Malaria is a critical public health problem resulting in substantial morbidity andmortality, particularly in developing countries. Owing to the development of resistancetoward current therapies, novel approaches to accelerate the development efforts of newmalaria therapeutics are urgently needed. There have been significant advancements in thedevelopment of in vitro and in vivo experiments that generate data used to informdecisions about the potential merit of new compounds. A comprehensive disease-drug modelcapable of integrating discrete data from different preclinical and clinical componentswould be a valuable tool across all stages of drug development. This could have anenormous impact on the otherwise slow and resource-intensive process of traditionalclinical drug development. The United Nations estimates that 6.2 million lives have been saved over the last 15 yearsowing to enhanced interventions to control malaria . Depending on the species, the parasite may also reside for aprolonged period in the host liver, resulting in relapsing malaria. Plasmodiumfalciparum is the most deadly of the five species of parasites, as it can causesevere malaria and is responsible for a majority of malaria-attributed deaths globally.Female The pipeline for malaria therapeutics is growing, in part because of the tropical diseasepriority review vouchers offered by the US Food and Drug Administration (FDA). Thesevouchers have provided a large financial incentive for pharmaceutical companies to developdrugs for neglected tropical diseases and malaria , 4. BecaHere, we review the current state of the art in malaria drug development and describe therole of modeling and simulation in drug development and regulatory decision making. Newexperimental techniques continue to emerge and provide the impetus to develop improvedmodels to predict clinical drug pharmacokinetic (PK) and pharmacodynamic (PD) properties.These new models have the potential to radically alter drug development and regulatorydecision-making processes and lead to more affordable and more effective drug therapy.Pharmacokinetics (PK): the study of the time course of how the body affectsthe drug, commonly characterized by absorption, distribution, metabolism, excretion, andtoxicity (ADMET) parametersPharmacodynamics (PD): the study of how the drug affects the body,describing the relationship between drug concentrations and pharmacological response. ACTs are required to demonstrate clinicalefficacy of >95% polymerase chain reaction (PCR)-corrected curerates at day 28 in the per-protocol population in clinical trials  recommends artemisinin-based combination therapies(ACTs) for the treatment of malaria. Artemisinin and its derivatives are potent andfast-acting drugs that cause a rapid decline in parasitemia during the first days oftreatment. The ACTs are remarkable malaria treatments that have activity against bothasexual blood-stage and sexual stages of parasite; however, the ACTs do not clear the latentliver stages of parasiteUnfortunately, resistance to the artemisinins, characterized by a reduced rate of parasiteclearance, has arisen in the Greater Mekong Subregion of Asia, and there is concern thatresistance is spreading. Decreased efficacy of artemisinins could result in exposure to thepartner drug in the combination therapy at a suboptimal level in a patient with an increasedparasite load. This partial treatment with less effective therapy may not completely clearparasites, allowing transmission to occur. An increased prevalence, severity, or both ofartemisinin resistance would be an enormous setback in the efforts to end malaria. With thisin mind, novel approaches to accelerate the development efforts of new malaria therapeuticsare urgently needed.a) the ability to block transmission ofgametocytes to mosquitoes, (b) the ability to block transmission to or byinsect vectors, (c) activity against hypnozoites, (d)activity against parasites sequestered in the liver (hepatic schizonts), and(e) the ability to clear the pathogenic asexual blood-stage parasites is a critical component of efforts to eliminate malaria. The ideal attributes requiredto achieve radical cure include  experiments,controlled human malaria infection (CHMI) in healthy volunteers, and clinical trials inendemic settings . Examples of MIDD for malaria therapeutics are discussed below for discovery,preclinical and clinical stages.The aforementioned attributes constitute a framework of requirements that can be used toevaluate new compounds along the development path. There have been significant advancementsin the preclinical in vitro and in vivo experimental models and clinical trials used togenerate information used to inform decisions about the potential value of new compounds.The experimental approaches include in vitro growth of settings –9. AltogPhysiologically based pharmacokinetic (PBPK) models: quantitative predictionof pharmacokinetic properties of chemicals based on in vitro physiological, biochemical,and physicochemical propertiesThe availability of large chemical libraries and high-throughput screening assays hasradically altered the process of generating and selecting lead compounds. High-throughputscreening assays have been successfully formatted for asexual parasites, and assays are indevelopment to evaluate activity in both liver-stage parasites and gametocytes. Quantitativestructure-activity relationship models can be used to identify the chemical structurescritical to drug activity and design . This information serves as input intophysiologically based PK (PBPK) models and provides predictions of the absorption,distribution, metabolism, excretion, and toxicity (ADMET) characteristics of potentiallyuseful drugs before compounds are actually synthesized . These PAfter synthesis, in vitro experiments provide additional information about the metabolicprofile, transporter activity, and potency against various stages of the parasite lifecycle. In vitro in vivo extrapolation (IVIVE) methods are then used to connect in vitro datato in vivo endpoints. IVIVE ranges from simple scaling factors and allometric approaches tocomplex mathematical models . These approaches are often used to predictdrug-drug interactions and inform study designs in drug development –13.In silico tools such as mechanistic PBPK models can be connected with a PD model in aneffort to predict clinical endpoints. The value of these in silico tools was recentlydemonstrated by a series of experiments in which novel compounds were designed from publiclyavailable information and were used to predict the activity, ADMET risk profiles, and invivo PK profiles to identify lead compounds. These selected compounds were then synthesizedand experimentally evaluated in vitro. The experiments showed general agreement betweenobserved and predicted physicochemical properties, demonstrating the utility of modeling andsimulation to identify potential lead compounds with acceptable PK/PD characteristics .Unlike many disease conditions for which preclinical models may not recapitulate the actualclinical condition in patients, the experimental model of malaria infection in huMouse canbe used to accrue data that help identify the target in vivo concentrations necessary forkilling malaria parasites that infect humans. Experiments with different strains ofparasites have been extremely useful for assessing drug activity against a variety ofresistant parasite strains that are currently circulating in areas with endemic malaria.These experiments constitute a preclinical testing paradigm for malaria therapeutics that ismore robust than is typically found in other therapeutic areas.Plasmodium berghei (a rodent-specific parasite species).As a result, the drug effect on P. berghei had to be extrapolated torepresent drug activity against parasite species that infect humans. Thus, it was crucial todevelop the use of immunodeficient mice to enable the study of P.falciparum infections in an experimental animal model. The evolution of thesemouse models began with nude mice in 1962, progressed to SCID mice in 1983, and subsequentlyhas evolved into more advanced mouse models that are capable of supporting the circulationof human erythrocytes infected with P. falciparum or P.vivax  models: quantitative description ofpharmacokinetics and pharmacodynamics to represent pharmacological relationships as a drugeffect over timeParasite reduction ratio: the regression-predicted fractional reduction inparasitemia at usually 48 h postinoculation50:IC concentration of drug in blood or plasma eliciting 50% ofmaximum parasite killing rateTypical preclinical experimental endpoints in the SCID huMouse model include survival,reduction in parasitemia, the effect of a compound on erythrocytic stages, time to parasiteclearance, relapse, and recrudescence .HistoriP. berghei , CHMI, Phase 2 dose-response, andPhase 3 confirmatory studies. The purpose of these studies is to determine the safety andefficacy profile of the drug and define the optimal treatment regimen. Data generated fromeach of these studies provide an opportunity for PK/PD modeling and simulation analyses toaid in the design of the subsequent studies and provide an estimate of the clinicalpotential of the compound.a)estimated human efficacious dose and exposure in human and (b)the noobserved adverse effect level (NOAEL) dose and exposure in the preclinical toxicity studies.Dose selection for FiH studies is further guided by the PD parameter estimations derivedfrom the SCID huMouse experiments and exposure predictions from animal PK studies. Ademonstrated exposure-response relationship in the SCID huMouse model increases theprobability of advancing an effective drug into later-stage clinical trials. Preclinicalestimations of effective concentrations, combined with the PK results from the FiH studies,can be used to validate and update PBPK models that are used in selecting the dosingregimens to be used for the CHMI studies.FiH studies are conducted in healthy volunteers using single and multiple doseadministrations, testing different doses and formulations in both fed and fasted states.Data obtained from these studies provide key PK information, such as drug exposure andhalf-life, and the identification and characterization of metabolites. The decision toadvance compounds to FiH trials is based on the margin between the . The sporozoite-induced malaria studies are conducted via directvenous inoculation of sporozoites or through infected Anopheles bites,whereas the IBSM studies are conducted via direct venous inoculation of blood-stage malaria.The pros and cons of using sporozoite-induced malaria or IBSM challenge models have beendiscussed . Although three njection. Followinjection. ThereafPlasmodium parasite . It took two decades to obtain enough safety datafor artemetherlumefantrine to be approved as a recommendation by the WHO for women in theirfirst trimester of pregnancy . Many ofThe innovative experimental models that have been developed for malaria, such as the SCIDhuMouse model and CHMI studies, represent opportunities to integrate the otherwisesequential and separate modeling and simulation exercises to advance MIDD for malariatherapeutics. A comprehensive disease-drug model capable of integrating the separatepreclinical and clinical trial components that could be used across all stages of drugdevelopment would be of great value.MIDD uses mathematical models to quantitatively investigate the interaction ofpharmacology, parasite biology, and disease pathophysiology. Models that incorporate thecomponents of the parasite life cycle and pharmacology –40 as weThese mechanistic mathematical models can characterize the PK/PD properties of drugs andexplore the impact of intrinsic and extrinsic factors that contribute to their intersubjectvariability and impact exposure and response across populations. The estimation of theirimpact can be used to provide a quantitative basis for optimal pharmacotherapy inhumans.Current models in use include both empirical population PK/PD models for evaluatingexposure-response relationships and semimechanistic models that represent differentbiological aspects of the parasite life cycle and pharmacology. The PK/PD models arise fromwork in a variety of disciplines and differ in focus and sophistication, as outlined bySimpson and colleagues . The modThe data coming from SCID huMouse model and CHMI studies, in conjunction with previouslypublished computational models, represent two ways of realizing the value of MIDD in malariatherapeutics. First, the CHMI studies are conducted on a cohort-by-cohort basis using anadaptive design. The data from the sequential cohorts of subjects enrolled in the CHMIstudies provide staged learning about the PK/PD of a drug. As each cohort completes a studycycle, the parameters and structure of a PK/PD model can be updated to yield improvedpredictions for planning the dose of the next cohort. This iterative approach of modelrefinement also provides an expanding knowledge base for use in performing clinical trialsimulations of future Phase 2 and Phase 3 clinical trials .Figure 3.Second, the data that accrue from a specific drug development program, pooled with datafrom other programs, provide a knowledge base for the development of a comprehensivedisease-drug model that is broadly applicable to drugs with differing pharmacology andacross different stages of development. Building such a model will require the coordinatedexpertise of scientists in many disciplines. A formal process for building, qualifying, andapplying a comprehensive disease-drug model is outlined in The process of creating a comprehensive disease-drug model begins with the development of aconceptual scheme. The conceptual scheme is a pictorial representation reflecting thecurrent understanding and interpretation of biology and pharmacology. This pictorialrepresentation is used as the basis of reconciling different knowledge domains and points ofview. As these ideas are incorporated into the conceptual scheme, the computational modelscan be adapted and used to perform a predictability assessment based on available data. Amodeling and simulation framework can be used to integrate data and provide evidence of thevalidity of the model, which is important for establishing the credibility of the approachand in supporting its use for decision making during drug development and the regulatoryreview process. An interdisciplinary team guides this iterative process of modeldevelopment, refinement, and validation. This systematic approach to model refinement,predictability assessment, hypothesis generation, and reassessment allows the strengths andweaknesses of a model to be identified and guides subsequent efforts to improve the model.The predictive accuracy of any mathematical model is dependent on three sources ofuncertainty: the data generated by experimental models, the validity of the mathematicalconstruct, and how well the model represents the system of interest. Consequently, theaccuracy and utility of the comprehensive disease-drug model for malaria is highly dependenton a continued assessment of the conceptual scheme and the experimental and computationalmodels. For example, newly recognized inadequacies of the computational model at any stageof development can lead to new experimental designs that address unappreciated gaps inknowledge. This may improve the accuracy of predictions in downstream applications of themodel.The value of the model is dependent on its successful application in two different venues:at various drug development decision-making milestones and during regulatory review. Each ofthese venues is explored briefly below.Federal regulations require that a new drug application must provide substantial evidenceof efficacy for the investigational drug or combination of drugs in adequate andwell-controlled clinical trials. Furthermore, the combination rule requires that data areavailable to demonstrate that each component of a fixed-dose combination contributes ameasurable advantage over the individual components . The typical development scenario for combination therapy relies on a factorialdesign that compares the drug combination dose ratios to monotherapy with each separatedrug to standard of care. These factorial design trials are expensive, are logisticallydifficult to perform, and limit the ability to deliver new malaria drug candidates in auseful time frame. They also expose a large proportion of the study population to over-and underdosing, which makes this study design questionable from a medical and ethicalpoint of view. Leveraging dose-response data from CHMI studies and using modeling andsimulation to guide trial design could decrease the number of trials necessary andincrease the success of the trials conducted.Figure 4). The randomization probabilities toeach treatment arm as well as the doses can change as knowledge about outcomes emergesthrough the lens of the disease-drug model. This type of pivotal platform study would pavethe way to a well-designed confirmatory trial.A new study design, known as the platform trial, enables the simultaneous evaluation ofmultiple interventions that can be added or dropped according to accumulating real-timeclinical trial information –58. ThisThere are three sources of efficiency in platform trials beyond those achievable intraditional studies. First, many different types of patients can be enrolled whileresearchers adaptively identify and/or confirm which patient/risk factor subsets—ifany—benefit from which of the therapies. Second, randomization probabilities can bemodified based on the accumulating data to increase the probability of assigningbetter-performing therapies within a patient subtype. Finally, models of response can bebuilt to predict long-term outcomes from short-term response data.For malaria, this innovative study design, combined with the application of acomprehensive disease-drug model, could have a dramatic effect on the costs andprobability of success of late-stage clinical trials. Clinical trial simulations couldpredict the outcomes of, and optimize, subsequent trial design. The models could make useof historical data to eliminate the need to replicate established exposure-responserelationships or reduce the size of comparator arms. For example, dose-responseinformation for the drugs of interest, including data from both monotherapy andcombination therapy, could be obtained from CHMI studies. The PK/PD information obtainedfrom CHMI studies can provide input to a comprehensive disease-drug model for malariacapable of representing the pharmacology of selected agents. Mathematical models couldmake use of these dose-response data to select rational candidates for combinationtherapy, guide study design for pivotal Phase 2 dose-response studies, and optimize dosingregimens. Clinical trial simulations of various scenarios could then be used to predictoutcomes and optimize the likelihood of subsequent trials. Furthermore, the models wouldaccentuate the learning during a trial and accelerate the changes in randomizationprobabilities to more effective treatment arms. For example, in next-generation factorialdesigns for malaria therapies, the treatment arms might include the standard of care, drugA treatment monotherapy, drug B treatment monotherapy, and combination therapy. Therandomization probabilities to each treatment arm as well as the doses can change asknowledge about outcomes emerges through the lens of the disease-drug model.In 2004, the FDA launched a two-year pilot program that featured 11 stakeholder meetingsand leveraged quantitative thinking to guide dose selection and clinical trial design. In 2009At a recent Clinical Pharmacology Advisory Committee Meeting on MIDD hosted by the FDA,participants raised a series of issues that define the level of credibility and validityof models intended to support regulatory decision making . SeveralThe Prescription Drug User Fee Act VI reauthorization provides an opportunity to assessperformance goals with a view toward ensuring the effectiveness of the human drug reviewprogram and advancing MIDD concepts. The FDA has proposed a pilot program for MIDDapproaches starting in fiscal year 2018; if antimalarial MIDD were explored as part ofthis pilot program, it would provide case studies and clarity on criteria for acceptancefor various approaches to antimalarial MIDD.SUMMARY POINTSExperimental models will continue to evolve and yield additional data andinsights. There is a need for valid quantitative links between the outputs ofthese experiments at all stages of malaria therapeutics research anddevelopment.Significant advances in the experimental models used in drug development formalaria therapeutics have the potential to support more mechanistic and integratedmodels of malaria biology and pharmacology that could provide early estimates ofthe clinical potential of new antimalarial drugs.The use of these models to define the exposure-response relationships has thepotential to improve the selection of doses to be tested, reduce the number ofpatients exposed to the wrong doses, and reduce the time and resources necessaryto successfully develop new antimalarial drugs.Proper qualification of complex mechanistic disease-drug models and ongoingdialogue with regulatory agencies about their proper use will be required for theexpanded application of MIDD for malaria therapeutics.This work was supported by the Bill and Melinda Gates Foundation. Kayla Ann Andrews,Thaddeus Grasela, and Luann Phillips are employees of Cognigen, which was contracted, inpart, by the Bill and Melinda Gates Foundation for the preparation of this manuscript. DavidWesche is a consultant for the Bill and Melinda Gates Foundation through Certara StrategicConsulting. Steven Kern is a full-time employee of the Bill and Melinda GatesFoundation.


The degree of stenosis of a carotid plaque is a well-established risk factor for ischemic stroke. Nevertheless, the risk of ipsilateral stroke in asymptomatic carotid stenosis remains low and new imaging markers are needed to better target which patients would benefit most from endarterectomy or intensive medical therapy. Ultrafast ultrasound imaging offers parameters helping at characterizing the carotid plaque by shear wave elastography and Ultrafast Doppler (UFD). We aimed at using these techniques to characterize 3 different ultrasound biomarkers: plaque stiffness heterogeneity, wall shear stress (WSS) and intraplaque micro-flows and to correlate these biomarkers with findings on computed tomography angiography (CTA) and the pathological examination.We present the case of a multimodal evaluation of a carotid plaque using ultrasound. Elastography has been coupled to the WSS assessment and the detection of intraplaque micro-flows by UFD. The data have been compared to CTA and to the pathology examination of the tissue after carotid endarterectomy.Elastography allowed at identifying stiff areas corresponding to calcifications, as well as a soft area corresponding to an intraplaque hemorrhage. The flow evaluation with UFD showed an increase of the WSS along the plaque and identified the presence of a plaque rupture, confirmed by the pathologist.Ultrafast ultrasound imaging is an innovative, easily accessible technique that provides imaging modalities on top of the conventional B-mode. Ultrafast ultrasound biomarkers such as plaque stiffness heterogeneity, WSS and intraplaque micro-flows could help to define the vulnerability of the carotid plaque in order to stratify patients that could benefit most from endarterectomy or intensive medical therapy. This is because current best evidence indicates a likely overall patient benefit using this approach. In addition, arterial imaging technology could be used to spare people from unnecessary and potentially harmful procedures or other treatments. It could be also used to better select persons for carotid procedures or particularly effective but risky or expensive medical treatments.Biomarkers to identify plaques at higher risk of ipsilateral stroke have been proposed with different imaging modalities, magnetic resonance imaging (MRI), ultrasound, and computed tomography angiography (CTA) . These bThe aim of our research is to provide biomarkers with ultrafast ultrasound imaging that could easily be combined to identify patients who would benefit most from endarterectomy or intensive medical therapy. In order to maintain the benefit of such interventions, the objective would be to identify plaques with an annual risk of ipsilateral stroke over 3%. In our laboratory we developed specifically dedicated sequences for the evaluation of the carotid plaque by using ultrafast imaging modalities. We present here the multimodal evaluation of a patient at “higher-than-average” risk of ipsilateral stroke based on the stenosis progression and a large plaque area. The aim of this case is to show a proof of concept on the feasibility of ultrafast imaging evaluation by combining several methods of tissue and blood flow analysis.2, with a grayscale median at 64 (no unit). A CTA confirmed the presence of a 70% NASCET carotid stenosis associated with calcifications  and a linear probe , provides stiffness mapping of the arterial wall superimposed to the B-mode image  and dropped below 1.45 Pa at the plaque descent (Two UFD imaging sequences have been used here: the first sequence was designed for ultrafast vector flow imaging (angle-independent quantitative Doppler mode) and the second sequence was designed for ultra-sensitive Doppler imaging of low velocity blood flows. To map the flow dynamics correctly in the carotid artery, it is imperative to resolve the beam-flow angle dependence problem. Vector Doppler imaging can estimate flow velocities at each point of the lumen without any angle correction , giving  descent .Unlike the vector flow imaging mode, ultra-sensitive Doppler mode has been developed to enhance the detection of low velocity flows with a high spatial resolution . AppliedDuring the intervention, the surgeon noticed the presence of a severe and calcified stenosis with a plaque ulceration. No complication, either immediately after surgery or after 1 year of follow-up, were noticed. Post-operative Duplex ultrasound revealed no residual stenosis.Gross examination of the removed plaque was assessed on a longitudinal section . It notiThis case illustrates a multiparametric assessment of a carotid plaque by UF. The vulnerability of the plaque was confirmed by the presence of a plaque ulceration and a large intraplaque hemorrhage described on gross examination. These characteristics had not been seen neither by Duplex ultrasound nor by CT scan. In addition to conventional B-mode, UF enables us to better identify structures by stiffness analysis and WSS measurement. In this case, UF identified a soft area with a low velocity flow disappearing in the anterior wall of the carotid artery. These data may attest the presence of a hemorrhage and ulceration in the plaque’s wall. The ultrafast vector flow imaging, recently developed, offers the unique opportunity to directly measure WSS by ultrasound. MRI previously tried, first by Computational Flow Dynamics and recently by 4D flow sequences with to address the direct assessment of the WSS. High WSS values were found associated with the presence of intraplaque hemorrhage , as we rLastly, the ultra-sensitive Doppler imaging aims at detecting micro-flows within tissue without the need for any contrast agents. This method can identify a flow irrigating into the plaque, which can indicate the presence of a plaque ulceration, a characteristic associated with an increased risk of embolic events . The higThe main limitation regarding the parameters presented is related to the presentation of a single case. The sole objective was to illustrate the feasibility of these ultrafast imaging modalities and no conclusion on the validation of the parameters presented can be provided here. A prospective validation is indeed required to demonstrate the value of these markers.In conclusion, UF is an innovative technology that conveys, on top of a B-Mode imaging, a shear wave elastography mode and an ultrafast Doppler mode leading to new parameters to better characterize the carotid plaque by measuring stiffness, WSS and micro-flows. The UF–plaque study (NCT03234257) is currently on-going aiming at demonstrating the correlation between stiffness measurement, WSS, micro-flows detection with plaque vulnerability criteria determined by histology on a prospective cohort of patients with carotid endarterectomy. For the future, the local evaluation of the carotid plaque by UF could provide an opportunity to perform a multimodal analysis including clinical criteria , and association with brain imaging criteria (silent infarction), in order to select patients at higher than average risk of stroke that would most benefit from carotid endarterectomy or intensive medical treatment.All datasets generated for this study are included in the article/The studies involving human participants were reviewed and approved by the Comités de Protection des Personnes, CPP N° 2017T2-13. The patients/participants provided their written informed consent to participate in this study.GG, LK, and TM wrote the manuscript. GG and EM performed the ultrasound analysis. PJ and J-MA performed the surgery. PB and KA performed the histological analysis. MP, OP, and JP performed the post-processing of the ultra-fast Doppler acquisitions. TM performed final approval of the version to be published and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy and integrity of any part of the work are appropriately investigated and resolved.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


This cross-sectional study examines the degree to which patient bills of rights and responsibilities from 50 academic hospitals in the US communicate a zero-tolerance policy against patient-perpetrated sexual harassment toward health care professionals. Therefore, we sought to examine the degree to which hospitals affiliated with the Association of American Medical Colleges (AAMC) complied with NASEM recommendations for addressing patient-perpetrated sexual harassment through a patient bill of rights and responsibilities and the degree to which language about patients’ rights mirrors the language about patients’ responsibilities.The National Academies of Science, Engineering, and Medicine (NASEM) report on sexual harassment recommends that hospitals maintain a clearly written patient bill of rights and responsibilities communicating a zero-tolerance policy for sexual harassment toward health care professionals.STROBE) reporting guideline.Between February and October 2019, we conducted a cross-sectional evaluation of patient bills of rights and responsibilities in 50 hospitals, randomly selected from 418 AAMC-affiliated hospitals using a random-number generator function in Stata, version 15.1 (StataCorp LLC). Two of us  independently reviewed and coded these documents for (1) a specific statement about patients’ responsibilities to refrain from harassment and sexual harassment and their right to receive care free of harassment and (2) the tone of the language communicating this expectation. The University of Michigan institutional review board deemed this study exempt because it did not meet the definition of human subjects research. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology , it was coded as specific. Patient bills of responsibilities that did not use these words but that used positive behaviors to describe expectations  were coded as suggestive. If neither approach was taken, this language was coded as absent. The same framework was used when examining patient bills of rights for expectations regarding harassment. This coding is presented in counts (percentages).Condemnation of patient-perpetrated harassment was evaluated in the patient bill of responsibilities. If the document used the words specific  because they clearly stated that the patient has the right to a discrimination-free experience  were coded as perience . Only 11perience .specific (it used the word harassment) (suggestive was used in 38 (97%) of the patient responsibility statements, including that patients were to be considerate of hospital staff  of the hospitals maintained a publicly available statement. Of the 39 statements, 1 (3%) was coded as assment) , whereasassment) , B. Langal staff .In this representative sample of AAMC-affiliated academic hospitals, nearly all of the hospitals (94%) specifically delineated patients’ rights to receive care free of harassment; however, the same emphasis on zero tolerance of harassment toward health care workers was rarely included in the patients’ responsibilities. Furthermore, the tone of the language used to describe patient responsibilities was suggestive rather than specific as in the patients’ rights and was in contrast to NASEM recommendations.6 Thus, this group of hospitals warrants specific attention.One limitation of this analysis is that the investigators were not blinded to the hospitals. Another limitation is a lack of generalizability to hospitals outside the AAMC. However, patient-perpetrated harassment is commonly experienced by trainees and is associated with isolation and burnout.Further investigation is needed to understand how patient bills of rights and responsibilities are disseminated, viewed, and interpreted among patients. Combating patient-perpetrated harassment may require hospitals to directly address patients by maintaining clearly written expectations with congruent language in the patient bill of rights and responsibilities.


A cutaneous sinus tract of dental origin is relatively uncommon and may easily be misdiagnosed because of its unusual occurrence and absence of dental symptoms. Extraoral drainage depends on the location of the affected tooth as well as on specific factors such as the virulence of the microorganism, resistance of the patient's body, and the relationship between anatomy and muscle facial attachments. An odontogenic cutaneous sinus tract is a pathologic channel that initiates in the oral cavity and exits at the cutaneous surface of the face or neck. It might resemble an ulcer, cyst, furuncle, or retracted, sunken skin . The purA healthy 17-year-old female patient presented herself to the dental hospital of the Faculty of Rabat complaining of discomfort and nonesthetic appearance of her face. The patient presented an extraoral sinus tract associated with the mental protuberance region, with an approximate size of 5 mm x 5 mm. The nodule was soft with minimal purulent discharge. During the interview, the patient reported that the sinus tract had appeared 3 months before and several treatment attempts based on antibiotics and dermatologic ointment had been made after visiting a dermatologist without any improvement . No intrA working diagnosis of an extraoral sinus tract related to a previously unknown traumatic injury to the incisors with consequent pulpal necrosis and periapical infection associated with the mandibular incisor tooth 31. Root canal treatment of tooth 31 commenced. The 31 was extirpated and dressed with a non-setting calcium hydroxide. Tooth 31 was then obturated with gutta-percha and hermetically sealed. The patient was monitored post-initial treatment at 2 months. The patient at 2 months review was concerned regarding the residual extraoral scarring affecting the mental protuberance region. For it we started the surgical procedure with the reflection of a full-thickness flap which allowed to observing that one of the fistulous tract extremities stuck to the bone around the apical region of 31. Consequently, the area was dissected to surgically remove the cord-like tract . After tCutaneous sinus tracts in the lower face is frequently described as an extraoral manifestation of pulpal-periradicular pathosis, might have other etiologies related to infectious disease such as mycobacterial infections, actinomycosis, deep fungal infections, osteomyelitis, or tumors such as pyogenic granulomas, epidermal cysts, squamous cell carcinomas, or congenital malformations such as thyroglossal duct cysts, brachial cleft cysts, and salivary gland fistulas . Like ouRadiographic findings are also important for the diagnosis and identification of affected teeth. Radiographic findings are also important for the diagnosis and identification of a carious tooth or retained roots along with the associated radiolucency periapical lesion, which may be a granuloma or a cyst . AlthougFacial lesions of dental origin are rare. This case highlights the significance of including odontogenic origins to the differential diagnosis of orofacial skin lesions. Early correct diagnosis, based on radiologic evidence of a periapical root infection, and treatment of these lesions can help prevent unnecessary and ineffective antibiotic therapy or surgical treatment, reducing the possibility of further complications.


Microlens arrays (MLAs) and MLA-based artificial compound eyes (ACEs) are the important miniaturized optical components in modern micro-optical systems. However, their optical performance will seriously decline once they are wetted by water droplets  or are polluted by contaminations in a humid environment. In this mini-review, we summarize the research works related to the fabrication of superwetting MLAs and ACEs and show how to integrate superhydrophobic and superoleophobic microstructures with an MLA. The fabrication strategy can be split into two categories. One is the hybrid pattern composed of the MLA domain and the superwetting domain. Another is the direct formation of superwetting nanostructures on the surface of the microlenses. The superhydrophobicity or superoleophobicity endows the MLAs and ACEs with liquid repellence and self-cleaning function besides excellent optical performance. We believe that the superwetting MLAs and ACEs will have significant applications in various optical systems that are often used in the humid or liquid environment. Microlens arrays (MLAs) and MLA-based artificial compound eyes (ACEs) play a key role in advanced micro-optical systems , otherwise, the nanostructures will cause obvious light scatter.In conclusion, the recent achievements related to the fabrication of superwetting MLAs and ACEs are reviewed. Inspired by the superwettability in nature, superwetting micro/nanostructures are integrated into the MLA surface, thereby endowing the MLA with anti-liquid and self-cleaning properties. Two strategies are generally utilized to prepare such a superwetting MLA. A superwetting microstructure can be created on the flat area between microlenses, resulting in a hybrid pattern composed of the MLA domain and the superwetting domain. On the other hand, the superwetting nanostructures can also be directly created on the top surface of the microlenses. The resultant MLAs and ACEs exhibit superhydrophobicity or superoleophobicity, which endows those optical components with excellent liquid repellence and self-cleaning function besides good optical performance.Although several superwetting MLAs and ACEs have been reported, the fabrication of such superwetting optical components is currently still in its infancy. Many development problems need to be solved before practically applying the superwetting MLAs and ACEs in various optical systems. Firstly, poor mechanical/chemical durability of the superwetting micro/nanostructures may result in the decline of the surface superwettability and optical performance for a superwetting MLA after a short period of use. Stable superwettability can extend the service life of the superwetting MLAs and ACEs. Secondly, the influence of the surface micro/nanostructures on surface wettability as well as the optical performance of an MLA should be deeply studied and optimized, which has a positive role in designing and fabricating different superwetting MLAs and ACEs. Finally, how to effectively integrate the superwetting MLAs with other optical components in a micro-optical system is also a technical problem. The adverse effect of the generated superwetting micro/nanostructures on the basic optical function of the micro-optical system should be minimized. We believe that the liquid repellence and self-cleaning function will broaden the applications of the superwetting MLAs and ACEs in the medical endoscope, solar cells, microfluidic system, bioscience research, ocean exploration, and other optical systems that are often used in the humid or liquid environment.FC directed and supervised the research. JY and HB wrote the manuscript. QY and XH contributed toward significant discussions and revised the paper. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Gene therapy orphan medicinal products constitute a unique group of new drugs which in case of hereditary diseases are usually administered only once at an early age, in the hope to provide sufficient gene product to last for the entire life of the patients. The combination of an exceptionally large single payment and the life-long clinical follow-up needed for understanding the long-term benefits and safety of gene therapy, represent new types of scientific, financial, social and ethical challenges for the pharmaceutical industry, regulators and society. With special consideration of the uniqueness and importance of gene therapy, the authors propose a three points plan for a close cooperation between the pharmaceutical industry and society to develop orphan gene therapy. (1) In fully transparent health technology negotiations a close and long-lasting, contractually fixed cooperation should be established between the manufacturers and local health-care stakeholders for sharing the medical and scientific benefits, the financial risks as well as the burdens of the post-authorization clinical and regulatory development. (2) The parties should agree on a fair, locally affordable drug price without the usually very high premium price calculated to compensate for the low number of patients. In case of high manufacturing costs, the companies should offer prolonged, 15–20 years long payment by installment with risk-sharing, especially considering that the late outcome of the treatment is unknown. Society should assist scientifically and financially organizing a specific patient registry, treatment in specialized hospitals and adequate long-term follow-up of patients, the coordinated management of financial transactions related to the risk sharing program. (3) The post-authorization treatment and prolonged observation of additional new cases coordinated by society should provide real world data needed for the modern complex regulatory evaluation of gene therapy products by the competent authorities. We assume that fair sharing of the benefits and risks as well as a well-organized cooperation of society with the industry in collecting real world evidence might result in better drug evaluation and improved accessibility due to lower prices. The outlined concept might support gene therapy more efficiently than the presently requested outstandingly high prices. The Orphan Drug Act accepted in 1983 in the United States of America (US) introduced officially the concept of rare diseases and the corresponding orphan drug designation to stimulate drug development in this area –10.The number of cases defining a rare disease varies throughout different jurisdictions and countries. Expressing the prevalence uniformly per 100,000 inhabitants, the approximate average threshold is between 40 and 50 patients suffering from a particular rare condition . RecentlDue to the rapid advancement of the molecular biological classification of diseases, many new agents targeting small disease entities with well-characterized genetic mutations and pathology will fall into the orphan drug category. The growing abundance of orphan drugs and especially the much higher prices of gene therapies will dramatically increase the financial burden of drug procurement and will leave less money available for the drug treatment of other diseases , 13–20. These problems will be discussed using as an example the treatment of spinal muscular atrophy (SMA) with the recently introduced gene therapy product Onasemnogene abeparvovec (Zolgensma®). This case was chosen considering similarities of Zolgensma® with other gene therapy products developed for hereditary diseases, such as once-only treatment, uncertainty of prolonged efficacy and safety and high financial outlay –20. MoreSpinal muscular atrophy is a genetic disease diagnosed in one in every 10,000–11,000 newborns . It has In the past, only supportive therapies have been available to alleviate the symptoms of the disease. Recently, two expensive orphan drugs either replacing the defective gene or targeting genetic transcription reached the market. The early studies mostly enrolled patients with severe, rapidly lethal SMA type 1 .Onasemnogene abeparvovec (Zolgensma®) is a complex molecule containing the gene that encodes the SMN protein, together with an enhancer and a promoter needed for proper gene function. The complex construct is linked to a viral vector necessary for carrying the molecule into cells. In genetically impaired neonate mice, a single subcutaneous or intravenous injection of this self-complementary adeno-associated virus serotype 9 construct could deliver enough SMN gene to neurons assuring the adequate further development of the animals for a prolonged time , 25. In In spite of the limited observation period, the once-in-a-lifetime treatment is tentatively assumed to provide a life-long effect. Considering that several factors might influence the duration and extent of the clinical results of gene administration , it is sZolgensma® received orphan drug designation together with the respective incentives both in the US and the European Union (EU). The U.S. Food and Drug Agency (FDA) granted fast track designation, priority review and a rare pediatric disease priority review voucher , 32. ConNusinersen (Spinraza®), the only other available effective specific treatment for SMA, is an antisense oligonucleotide which binds to the splicing silencer region on the SMN2 pre-mRNA. The modified mRNA is translated into functional SMN protein –41. The The 2.1 million US$ list-price for the once-only treatment with Zolgensma® became the highest price requested ever for a new medicinal compound . For theIn this paper, only the US prices are analyzed, because in the USA the companies themselves determine the list price. The list price will be usually modified and specific rebates will be agreed upon in confidential negotiations with the various payers in the US. Nevertheless, the outstandingly high price difference between the list prices of Zolgensma® and other medicinal products will most probably remain similar in other countries and will exert an exceptionally high impact on the local drug budgets. For example, in Germany a price of 1,945,000 EUR, close to the US price was announced, which will be renegotiated based on the local cost-effectiveness evaluation after 1 year. In other EU Member States, the negotiations are ongoing . The comFollowing the above short presentation of the development, marketing authorization and pricing of Zolgensma®, let us analyze what we can learn from this experience for improving both the affordability and post-marketing evaluation of gene therapy products. The need of higher priced orphan drugs for small patient populations suffering from rare diseases is now ethically broadly accepted. This led to the orphan drug legislation with the provision of economic incentives to the pharmaceutical companies for supporting drug development for rare diseases. Regulatory agencies devised several further means for making life-saving drugs available to the patients as early as possible after the confirmation of basic efficacy and safety parameters , 31–35. It is also obvious that a considerable part of the required post-authorization clinical observations has to be performed by society. The many additional cases and the very long follow-up time needed for proving the long-lasting effectivity and safety of gene therapy place exceptionally high burden also on the health-care system. Most of the data provided by society will fall into the category of real world evidence feeding the above-mentioned voluntary registry of Zolgensma® treated patients. The coherent collection and the combination of data emerging from classical clinical trials and real world data is becoming an increasingly important approach for the regulators to offer a well-balanced evaluation of orphan products as suggested by Eichler et al. . Much orThe construction and manufacturing of the gene therapy medicinal products are material factors determining their exceptionally high prices. In addition, the overall large expenses of broad prior research leading to the development of high-tech products are often considered in the price calculation and are frequently cited for explaining their exaggerated prices. However, this is a questionable argument and it should be judged critically, since a large part of previous basic research used was probably covered by public funds and its results are available from the scientific literature . In addiHealth insurance companies around the world find it hard to incorporate the very highly priced gene therapies into their policy when the long-term outcome is not yet proven. Besides the high budget impact, they consider also the effect of the disease on the patients and caregivers , 9. The A frequently asked question is how far society can cover the upward pricing spiral elicited by new types of drugs, primarily by gene therapy products. In the US, ICER convened a special expert meeting for discussing evidence generation, assessing pricing, value, and affordability of gene therapy , 59, 60.However, such non-official acquisition strategies are too fragile to provide equitable access for all the patients needing expensive orphan drug treatments. Indeed, there is a real possibility that due to the intensive pressure of few patients for obtaining disproportionally expensive treatments, an increasing fraction of the local drug budgets might be channeled away from the majority of patients suffering from more frequent diseases, thereby increasing the health-care burden of other patients. The more likely possibility is that without establishing a properly balanced price band for gene therapy products, the present drug reimbursement system will not be able to cover gene therapy distorting further the equity of access to required drugs . InternaThe above discussed considerations led us to envisage a more sophisticated solution involving both the pharmaceutical industry and several healthcare-related organizations participating in the clinical development and use of gene therapies. We propose that due to the special clinical pharmacological properties of orphan gene products and their exorbitantly high price the pharmaceutical industry should be persuaded by society to accept a more generous benefits and risks sharing program to improve the access of patients to the drug. On the other side, the public should provide much more effective support for the investigation of the effectivitiy of gene products. The aim should be established by a goal-oriented long-term contractual cooperation between the parties.The concept of benefit sharing is essentially a “gesture of solidarity,” meaning procedural and distributive justice in drug research stipulating the ethical obligation that some of the advantages gained by a sponsor should be shared with the subjects and communities participating in the project. Unfortunately, benefit sharing in clinical research is not enshrined into a binding legal system. Benefit sharing is frequently described in relation to international clinical drug development performed by capital strong pharmaceutical companies in developing countries . It can Benefit sharing should be accompanied by a risk-sharing agreement covering 15–20 years which is in line with the clinical observation period prescribed by the FDA for recording long-term effects , 28. TheBeside the benefit- and risk-sharing programs offered by the pharmaceutical companies society must also add its share to effective post-authorization activities primarily in the organization and support of an added real-world evidence program. The rapid improvement of advanced therapy products provides a moving target for the real world follow-up. The observations should be carried out in specialized medical centers able to provide scientifically high-level data extending those derived from the earlier small, frequently single-arm regulatory clinical trials. These centers should also scientifically contribute to the continuous development of these new type of products targeting only small patient groups . For sucThe pharmaceutical industry is also aware of the need for a well-organized post-authorization cooperation with the society. At a special expert meeting dealing with the affordability of gene therapy, they formulated very similar recommendations . The phaThe optimal organizations for negotiating fair financial agreements and efficient cooperation between the pharmaceutical industry and society are the health technology assessment groups. It is now broadly accepted that they cannot deal exclusively with financial aspects, they must consider also ethical and societal values such as good quality care, equity and solidarity as formulated for example in the value statement of EUnetHTA . The speThese divergent financial and ethical views must be weighted when health technology assessment groups make price and reimbursement decisions. High cost-effectiveness thresholds will decrease the number of patients treated and further use will be self-limiting due to a substantial increase of the financial burden for the society. Our principally different approach advocating the decrease of the premium price with parallel increase of the real-life research contribution by society might be quite advantageous for the pharmaceutical industry due to an increased number of patients involved and improved evaluation of the real world effectivity. Based on real-life evidence an outcome related payment procedure could be also established in which the price would be adjusted stepwise according to the maturity of the experience. The most important condition for the negotiated contractual approach is to make available a completely transparent scientific and financial development documentation by the industry as well as by the society covering their real life research contribution. On this basis, the parties could agree on a fairer price considering the proven research, development, production and marketing costs without calculating extra premium since the company gets financially and scientifically valuable real world research support as a compensation. Such evaluation needs the expertise of many different specialists. Health technology evaluations are presently done at national or even at lower levels of society resulting in qualitatively quite different decisions. Reaching the market is prolonged and regionally fragmented making the organization of rational, broad, cooperative gene therapy programs difficult. Therefore, we believe that such complex evaluation should be done internationally. Fortunately, we have now several international health technology organizations such as the INAHTA, EUnetHTA, RedETSA, HTAsiaLink, WHO-HTA cooperations covering different regions . These oThe usually expensive production of advanced orphan gene medicinal products will keep the cost high even without the added premium price. Society has to make difficult decisions as to how much of the available healthcare resources can be made available for treating patients with gene therapy. Purchasing these expensive medicinal products will frequently necessitate accruing additional grants from private and public research funds. Besides making these decisions, society should help to organize and manage disease specific groups for registering and following the patients. These organizations should also be responsible for collecting the data on patients for managing drug procurement and payments according to the risk-sharing program. The combination of all these organizational and financial tasks in special funds are of great practical importance for supporting the high-level scientific evaluation of all the treated patients and assuring a reliable long-term financial partnership with the sponsor . ConsideThe last important pillar of the long-term agreement should be based on the close cooperation of the patient groups with clinical researchers and hospitals. In this model, the patient groups would play a significant organizational role in the research programs especially during the post-authorization, real-world experience based development. This cooperation should be associated with an educational program teaching patient groups to represent people suffering from the same disease considering also the impact on the wider society. It is important that these patient organizations should be self-supported and independent of industrial economic influences . We beliSumming up, we are convinced that for firmly anchoring gene therapies in the medical practice fundamental changes are needed in their pricing and regulatory evaluation. According to our opinion, the further increase of cost-effectiveness threshold leading to a higher price could support development at the producer side, but poor affordability would significantly hamper the broad clinical use of gene therapy. We suggest that close financial, regulatory and clinical cooperation between the pharmaceutical industry and society could decrease significantly the price by generous benefit and risk sharing offered by the industry coupled to compensating gestures by society. The latter should assume responsibility for the medical and financial organization of a thorough real-life evaluation of gene therapy on a large patient population needed for the modern, complex regulatory evaluation. We hope that these ideas will promote further debate among all stakeholders to support broad access to gene therapy in the future.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.SK-F initiated this work and wrote the manuscript in close scientific cooperation, consultation, and discussion with the co-authors. All authors are members of the IFAPP Ethics Working Group. All authors contributed to the article and approved the submitted version.LL was employed by Eli Lilly & Co. LC was employed by Craveri Pharma. SN was employed by Ferozsons Laboratories Ltd. JS was employed by PPH plus GmbH & Co. KG. BF-B is a consultant affiliated with IFAPP and IFAPP Academy. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


An outbreak of the disease known as COVID-19, which originated in Wuhan in the Hubei province of China, has rapidly spread to all continents of the globe.It is uncertain what the eventual toll of the pandemic will be in Africa; however, there has been a suspicion that the looming pandemic may hit harder than it has the rest of the world.6While old age has consistently been associated with a higher risk of poor outcome, children appear to have escaped the worst of the disease.13The COVID-19 pandemic has placed unprecedented strain on health services around the world, and paediatric surgical services are no exception.Non-essential surgical and non-surgical activities should be curtailed to provide surge capacity for the expected pandemic-related influx. This is consistent with guidelines from many surgical societies worldwide19 24Paediatric surgical services in Africa are characterised by significant delays in health-seeking and within the referral chain.The change to non-operative treatment in eligible patients for certain conditions, for example, appendicitis that is being contemplated, may find less success in Africa, where a higher proportion of patients have complicated disease not amenable to non-operative treatment.et al reported on eight infants who tested positive on rectal swabs even after having tested negative by nasopharyngeal swabs.Perinatal transmission of SARS-CoV-2 has not yet been demonstrated in recent small case series and a systematic review.Experience from previous pandemics has demonstrated that HCWs are the lynchpin of resilient surgical systems during an outbreak. During the Ebola outbreak, the unfortunate death of 25% of the surgeons in one institution has led to a 97% reduction in surgical volumes,41Children have been called ‘the link in the transmission chain’ because of their importance in facilitating and amplifying viral transmission.Hospital visitors have been implicated as vectors in pathogen transmission during the SARS-CoV-1 outbreak of 2002–2004,Experiences from this and past epidemics show that in health emergencies children, the most vulnerable members of society suffer disproportionately.The incidence of family violenceSurgical training programmes are an additional casualty of the social distancing measures and surgical rationing. The reduction in elective surgical cases and clinics, as well as contact between teachers and trainees, has brought challenges in the delivery of surgical education worldwide.A recent global review of paediatric surgical workforce density showed that a minimum of four paediatric surgeons per million children under 15 years of age would be required to achieve a survival of >80% for a group of four bellwether paediatric surgical conditions.The pandemic has also presented opportunities for surgical education. Virtual didactics are poised to increase the size of the classroom and to allow easier collaborative learning between teams in different hospitals or countries. This is occurring all over the continent and the practice may persist long after the pandemic is over.The inexorable spread of COVID-19 around the world continues unabated and threatens to affect every clinical specialty. Children have unique needs and suffer disproportionately during health emergencies and therefore require enhanced protection. Paediatric surgeons in Africa have an important role during times such as these and should use tailor-made, context-appropriate strategies to minimise the impact on our patients and HCWs. Protection for HCWs should be the foremost in the minds of policy-makers as they are a precious and irreplaceable resource.


In this special issue, we focus on the role of nutrition in the therapy of nonalcoholic liver disease (NAFLD). Currently, substantial evidence exists suggesting the important role played by intestinal microbiota in the pathogenesis of NAFLD. Functional connection of microbiota with the mucus layer, the enterocytes, and the gut immune system is crucial for intestinal permeability. Moreover, many dietary factors influencing the gut microbiota may lead to the elevation of intestinal permeability and increase the risk of NAFLD (as well as obesity and insulin resistance). It has been established that the presence of liver steatosis was associated with increased colonic permeability and lower adherence to the Mediterranean diet and a healthy lifestyle .The meta-analysis by Stachowska and colleagues  showed tNatural substances may exert antioxidant and anti-inflammatory effects and successfully support NAFLD therapy. Jakubczyk et al. performed a meta-analysis examining the effects of resveratrol supplementation in NAFLD patients. The study revealed no significant impact on reducing anthropometric parameters, lipid profile, glucose metabolism, or arterial pressure. The currently available evidence is insufficient to confirm the efficacy of resveratrol in the management of NAFLD, thus further research is needed to clarify this issue .Inulin is a natural soluble fiber used as a food supplement and food additive improving nutritional value. Despite many reports on the health-promoting properties of dietary fiber, the effect of inulin on the liver seems unclear. Pauly et al. showed that relatively short-term inulin consumption in mice with an intact gut microbiome, disturbs cholesterol and bile acid metabolism and may have detrimental effects on liver function. Lowering of plasma cholesterol, induction of cholestasis, and mild liver injury were noted .The gut microbiome is one of the important factors in chronic liver disease progression. Hussain et al. studied the association between diet and the microbiome of the proximal gut in patients with liver cirrhosis . They coBile acids (BA) are synthesized in the liver from cholesterol and are important signaling molecules in a gut–liver axis. Primary BA undergo biotransformation to secondary BA by the intestinal microbiome and are reabsorbed into the portal tract of the liver. BA act as important signaling molecules of the nuclear farnesoid X receptor (FXR) and the membrane-associated G-protein-coupled bile acid receptor-1 (GPBAR-1) .


In this study, we present a comprehensive review of polymer-based microelectromechanical systems (MEMS) electromagnetic (EM) actuators and their implementation in the biomedical engineering field. The purpose of this review is to provide a comprehensive summary on the latest development of electromagnetically driven microactuators for biomedical application that is focused on the movable structure development made of polymers. The discussion does not only focus on the polymeric material part itself, but also covers the basic mechanism of the mechanical actuation, the state of the art of the membrane development and its application. In this review, a clear description about the scheme used to drive the micro-actuators, the concept of mechanical deformation of the movable magnetic membrane and its interaction with actuator system are described in detail. Some comparisons are made to scrutinize the advantages and disadvantages of electromagnetic MEMS actuator performance. The previous studies and explanations on the technology used to fabricate the polymer-based membrane component of the electromagnetically driven microactuators system are presented. The study on the materials and the synthesis method implemented during the fabrication process for the development of the actuators are also briefly described in this review. Furthermore, potential applications of polymer-based MEMS EM actuators in the biomedical field are also described. It is concluded that much progress has been made in the material development of the actuator. The technology trend has moved from the use of bulk magnetic material to using magnetic polymer composites. The future benefits of these compact flexible material employments will offer a wide range of potential implementation of polymer composites in wearable and portable biomedical device applications. Over the past few years, there has been an increasing demand on the employment of flexible materials for various applications in biomedical field. This has led to the significant growth of the movable structure development ,2. The fThe flexibility characteristic of polymer is beneficial in obtaining large and controlled structure deformation of the movable parts. These movable parts include diaphragm (thin membrane), pillars, cantilevers or the combination of pillars and movable structures ,6. This Studies on electromagnetically driven MEMS actuators in the field of biomedical instrumentation are currently increasingly popular in which the improvements of the mechanical structures and the material properties of the movable part became the most interesting topics. The development studies were done in order to enable efficient and precise structure movement for control, manipulation or analysis purpose of the biomedical samples ,13. ThesSeveral reports have been recently published to introduce the interaction between magnetic flux generated from electromagnetic coil and rotating magnet field ,16. ThisThe MEMS structures are usually made of glass, silicon, silicon nitride and metals ,20. ThosOn the other hand, polymers in MEMS have been used since several years ago as a photosensitive material , sacrifiIt was also reported that microstructures working under extreme vibration condition like actuators need enhancement in terms of material quality, design and technological concepts in order to increase the lifetime and effectiveness of the structures . TherefoSome popular polymers have been identified and explored to become the flexible material for actuation purposes. The common actuator materials that have been reported in the literatures include PMMA, parylene, polyimide and PDMS elastomer. The properties of those materials are summarized in In general, MEMS actuators can be driven either by mechanical actuation or non-mechanical actuation. Mechanical actuation mechanism with a diaphragm (membrane) as the moving part is primarily utilized in MEMS devices . CompareA large number of mechanical microactuator devices has been demonstrated including microrelays, microvalves, optical switches and mirrors, micropumps and many others that can be found in various applications. These actuators use different mechanical actuation principle such as piezoelectric, electrostatic, electromagnetic, thermo-mechanic, thermo-pneumatic and shape memory. The major advantages of electromagnetic actuation are the generated high magnetic force that enables large membrane deflection and high tunable frequency capability. In addition, rapid generation of electromagnetic field enables membrane deformation in 2 directions with very fast vibration rate . AdditioNot many designs for magnetic microactuators specifically used in biomedical field are reported in literature. The basic mechanism of electromagnetic actuation involves the interaction between magnet and electromagnetic field that intensively generates the magnetic force. This interaction produces high frequency vibration of the movable structures, such as membrane and pillars, hence enables various implementation of biomedical instrumentation.Thielicke et al.,  explaineIn general, the magnetic membrane actuation is achieved by the deformation of the movable membrane due to the generated magnetic force acting onto the membrane. The common structure of a magnetic actuator is schematically displayed in z-axis is generated. The magnetic force known as Lorentz force V of the body . T. T115]. A valveless EM micropump reported by Yamahata et al.  used comAnother valveless EM micropump having a composite magnetic membrane of Fe + PDMS was reported by Nagel et al. . Weight Shen and Liu fabricated a PDMS-based magnetic composite membrane with IPDP thin film stacked design a and embA complete PDMS-based micropump including the structure, the membrane and the valveless microfluidic system was reported by Zhou and Amirouche . The actSaid et al.  combinedElectromagnetically actuation of flexible membrane incorporating microvalve for micropump application has been also reported by Sadler et al., as shown in Polymer-based microvalves used to manipulate the fluid flow have been reported by Gaspar et al. . The actTo summarize, since 1995 there have been many developments in microactuator device design and materials for micropumps and microvalves incorporating elastic membrane, as listed in It can be concluded that the polymer-based micropump and valves were able to precisely control the delivery of the fluidic sample and obtained fluid flow range from 10 mL/min down to several nL/min. Innovations in the membrane material and structure and the use of the latest technology in several ways are still necessary to meet the needs and requirements of the biomedical instrumentations.Magnetic polymers found its important role in microfluidic mixer system which is mostly used as the basic material for the passive part of the system such as the channel and chamber formation in lab on chip system. On the other hand, the polymer has been playing the potential role as an active part in order to improve the mixing performance of the microfluidic system, especially for the bio-cell analysis. This is called active microfluidic mixer, which means that the mixing mechanism is due to the turbulences of the fluidic sample inside the mixer chamber, usually based on magneto-hydrodynamic and magnetic structure actuation, which is driven by an external magnetic field .In 2018, Tang et al. presented a research on embedded flexible magnets in PDMS membrane . Three d0.7Ce0.3)10.5Fe83.9B5.6 powder are then magnetized to produce permanent magnetic structures with bidirectional deflection capabilities, making them highly suitable as mixers controlled by electromagnetic fields. Similar to this concept, Zhou et al. [3O4 magnetic particles. Through an external magnetic field exposure, the magnetic pillar will react in rotation mode.Turbulence inside the fluidic chamber to improve mixing performance can also be produced by using pillars rotation as reported by Rahbar et al. . Here, au et al.  reportedFurthermore, Pawinanto et al.,  has deveIn this study, a comprehensive review on electromagnetically driven MEMS actuators with polymer-based movable structure is presented. The flexible characteristic of polymer is beneficial in attaining large and controlled structure deformation of the movable parts, such as thin membrane diaphragms, pillars or cantilevers. Significant discovery of polymer-based functional material has led to a wide range application of electromagnetic MEMS actuator. The flexible actuator structure with high magnetic property plays an important role in various biomedical instrumentations, such as lab on chip and drug delivery system.These actuators can function as micropumps, microvalves and micromixers which execute the imperative roles of delivering biomedical samples. The wonderful combination between flexibility and magnetic properties of the magnetic polymer actuators can accurately control the microfluidic flow in a microchannel and determine its direction. In addition, the fluidic samples can be delivered precisely at a wide range of fluid flow rate, from 30 mL/min down to several nL/min. It will be a challenging effort to widen the flow rate range of an electromagnetic injection system which may require significant arrangement in pump and valve system design. This will eventually improve the reliability and quality of the electromagnetically driven microactuator system, specifically designed for drug delivery and artificial kidney.The actuator structure also plays an important role as an active microfluidic mixer in the preparation process of the biomedical samples for drug delivery and lab on chip system. The polymer actuator can potentially reduce the mixing time and increase the mixing index. The increase of fluid sample turbulence inside the mixer chamber driven by external magnetic fields improves the mixing performance. Here, the innovation in design and fabrication technology for magnetic polymers introduces more compact mixer structure.The presence of bulk permanent magnet attached onto the actuator has been identified as one of the main drawbacks for making an electromagnetically driven MEMS actuator to be large in size. Hence, it is crucial to make the actuator structure compact, as this will ultimately reduce the overall size of the system. A polymer membrane diaphragm with embedded magnetic nanoparticles can become a compact actuator with better mechanical properties. The developmental concept for magnetic actuator has evolved from the utilization of hard and fragile materials to more flexible polymeric materials with matrix magnet and now progresses towards embedded magnetic nanoparticles polymer composites. In the future, the polymer composites will eliminate the need of a conventional bulky permanent magnet in electromagnetic actuators.To conclude, much progress has been made on magnetic actuator development and the future trend shows magnetic polymer composites as the new functional materials for flexible biomedical device technology. The magnetic polymer composite will be a fascinating material to be implemented in wearable and portable biomedical device applications that are currently and rapidly growing.


Decreasing cost and increasing technology access in schools places 3D immersive virtual reality (VR) within the reach of K-12 classrooms Korbey, . Educato VR has the potential to broaden the reach of the traditional classroom by addressing limitations of K-12 classroom environments. VR simulations that engage learners as explorers shift the focus from content acquisition to active inquiry  to head-mounted displays (HMD) has decreased the cost of VR, yet these technologies have focused heavily on the individual's experience  microscopy  microscopy  at MIT (#10707095354).MT did the planning for the paper, read and synthesized literature notes, and wrote the paper. AW read and compiled paper notes, wrote the section on students' understanding of cells, and helped review drafts of the manuscript. DR helped review the paper from a game designer perspective and edited the paper. EK advised MT as she formulated the paper idea, helped imagine the direction for the paper, and reviewed and edited the paper multiple times, providing indepth feedback.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Isoflavones are dietary phytoestrogens commonly found in soy-based products. The widespread presence of isoflavones in soy infant formula and breast milk may have long-lasting effects on the development of sex hormone-sensitive organs like the skeleton. Animal early-life programming models are suitable for testing the skeletal effects of pre- and neonatal exposure of soy isoflavones. This review aims to collate the impacts of early-life exposure of soy isoflavones as evidenced in animal models. The isoflavones previously studied include daidzein, genistein, or a combination of both. They were administered to rodent pups during the first few days postnatal, but prolonged exposure had also been studied. The skeletal effects were observed when the animals reached sexual maturity or after castration to induce bone loss. In general, neonatal exposure to soy isoflavones exerted beneficial effects on the skeletal system of female rodents, but the effects on male rodents seem to depend on the time of exposure and require further examinations. It might also protect the animals against bone loss due to ovariectomy at adulthood but not upon orchidectomy. The potential benefits of isoflavones on the skeletal system should be interpreted together with its non-skeletal effects in the assessment of its safety and impacts. Developmental programming or imprinting refers to the phenomenon whereby changes in the early development of an organism can exert long-lasting impacts that manifest during adulthood . AntenatThe skeletal system is responsive to hormones and hormone-like substances. Prenatal and neonatal exposure of the skeletal system to hormonal stimuli might alter the trajectory of skeletal development. A single dose of estrogen at the first postnatal day could increase the bone mineral density (BMD) and cortical thickness of male mice at the prepubertal stage, but the inverse happened at the stage of peak bone mass acquisition . PrenataIsoflavones are phytoestrogens present abundantly in soy-based products  and are The skeletal effects of soy isoflavones take decades to develop, and the planning of epidemiological studies or interventional trials on this topic is difficult. Animal models of prenatal and neonatal programming enable us to have a glimpse of the potential effects of soy isoflavones on skeletal developments. Animals like rodents have a relatively short life cycle, so developmental changes can be examined within a shorter time. The purpose of this review is to examine the skeletal effects of early-life exposure to soy isoflavones in animal models of prenatal and neonatal programming.In toxicity testing, the neonatal life stage refers to the period from birth to 3 weeks of age , but theMost studies examining neonatal exposure of soy isoflavones on the skeletal system used mice as the model organism. The soy isoflavones studied included DAI, GEN, or a combination of both. Since the binding affinity of different types of isoflavones on biological targets, like estrogen receptors , are difThe soy isoflavones were administered subcutaneously during the first few postnatal days, and the skeletal outcomes were assessed when the mice reached maturity (4 months of age), with diethylstilbestrol (DES) as the positive control. The dose and type of isoflavone used in each study were different ; thus, the skeletal effects may not be comparable between studies. Other variations of the models exist. Two studies assessed the skeletal effects of prenatal exposure of folic acid (FA) and postnatal exposure of isoflavones on mice , 21; thuIn the prenatal and postnatal rat model , 23, soyAnother study exposed the mouse pups with isoflavones, castrated them in the fourth month, and assessed their bone health status in the eighth month . The casThe composition of the control diet is essential to ensure a fair comparison between the isoflavone-supplemented and control groups. Long-term supplementation of different diet regimens with and without soy isoflavones or protein can modify body composition and metabolic profile of the animals . Most stThe design of the studies is shown in Bone mineral density (BMD) assessment through dual-energy X-ray absorptiometry in animals allows non-invasive longitudinal changes in bone mass . NeonataOverall, neonatal exposure to isoflavones increased BMD of the mice at sexual maturation, and the effects were slightly better in male mice. However, it did not protect male mice against bone loss due to sex hormone deficiency. These observations suggest that both androgenic and estrogenic stimulation are essential in the development of the skeleton in males , 31. On BMD cannot differentiate between the trabecular and cortical compartment, and it has a low resolution . MicrocoSkeletal microarchitecture is a major determinant of bone strength, which can be studied through microcomputed tomography . NeonataOn cortical bone indices, DAI increased the cortical area of the femoral neck and midpoint . DAI, GEOverall, data on neonatal exposure of isoflavones on bone microarchitecture is limited. The available study showed that improvements were site specific. The lumbar spine and femoral neck are trabecular rich; therefore, the improvement in trabecular indices is better. The femoral midshaft is cortical rich; hence, cortical improvement is more apparent. The variations in bone composition could significantly influence the effects of isoflavones on different bone regions, which dictates bone strength.The ultimate measure of bone health is skeletal strength, which predicts fracture risk. The usual indices include ultimate/peak load, which refers to bone strength under certain specific loading conditions, and stiffness, which refers to the resistance of the bone against deformation . NeonataOn the other hand, neonatal DAI exposure increased the femoral neck and midpoint peak load in adult male mice but not in female mice . The effOverall, neonatal isoflavone exposure generally improves the bone strength of mice, but the skeletal sites vary due to the type of isoflavones present.Bone remodeling refers to the tightly regulated process of bone resorption by osteoclasts and formation by osteoblasts . The bonOverall, neonatal isoflavone exposure might suppress the formation of osteoclasts, but this observation was not reflected in the bone resorption markers. Perhaps this change is transient and has normalized upon adulthood.Other studies reported a longer period of isoflavone exposure involving the prenatal and neonatal periods. We limit our discussion to studies with postnatal exposure within the limit of the neonatal period of life. Tousen et al.  reportedOverall, in contrast to neonatal exposure, prenatal plus postnatal exposure of isoflavones exerted negative effects to the bone. This observation might be related to the critical period of intrauterine exposure. It was reported that soy isoflavones could regulate the epigenetic process of embryonic stem cells . WhetherCurrent findings from animal experiments are summarized in Prepubertal exposure of soy isoflavones also influences skeletal health at adulthood. Zhang et al.  showed tHotchkiss et al.  comparedSoy isoflavones affect skeletal development through direct and indirect action on bone cells. In this section, the actions of soy isoflavones on bone cells, through DNA methylation and thyroid hormones (TH), are discussed.Ereg and Efcab2, as well as downregulation of Hrc, Gli, and Ifim5 in MC3T3-E1 preosteoblastic cells  . The difIn silico analysis showed that isoflavones could bind to thyroid receptors, but this effect has not been validated in vitro (On the other hand, soy isoflavones exert their effects on the skeletal system indirectly through interference with TH homeostasis . Congeniin vitro . Isoflavin vitro . Soy isoin vitro , which pin vitro . Howeverin vitro .Soy isoflavones may also affect skeletal health through other indirect mechanisms. A multigeneration supplementation study showed that soy protein concentrates and soy isoflavones slowed down the weight gain and reduced the insulin level of the rats . The redOverall, soy isoflavones modulate a complex network of factors influencing bone health. The net effects seem to be beneficial, considering the phenotypic response of the skeletal system on soy isoflavone supplementation. The mechanisms of action of soy isoflavones and soy protein isolates are summarized in Early-life exposure to isoflavones, especially during the neonatal period, enhances BMD, skeletal microstructure, and strength in adulthood. Similarly, prepubertal or life-long supplementation suggested beneficial skeletal effects, which may reduce the skeletal negative effects of castration at adulthood. On the other hand, the prenatal plus postnatal exposure models reveal the negative effects of isoflavones. Further, basic research on the influence of isoflavones on the epigenetic process in embryos would explain the skeletal phenotypes observed. Mechanistically, the skeletal protection may be due to their direct actions on bone cells favoring osteogenesis and DNA methylation. The effects of isoflavones on TH homeostasis could bring more harm than benefits to the skeleton at this life stage. Therefore, soy infant formulation should not be initiated without proper evaluation of the risk and benefits. The evidence presented in this review should also be interpreted together with evidence from other organ systems, especially sex hormone-sensitive organs to assess the impacts of early-life exposure of isoflavones on developmental health holistically.K-YC and K-LP conceived the review. K-YC performed the literature search and drafted the manuscript. K-LP validated the search results and reviewed the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Currently the investigation on recycled cement concrete aggregate has been widely conducted, while the understanding of the recycled polymer concrete aggregate is still limited. This study aims to fill this knowledge gap through the experimental investigation on mechanical and durability performance. Specifically, the remolded polyurethane stabilized Pisha sandstone was collected as the recycled polymer concrete aggregate. The remolded Pisha sandstone was then applied to re-prepare the polyurethane-based composites. After that, the mechanical performance of the prepared composites was first examined with unconfined and triaxial compressive tests. The results indicated that the Pisha sandstone reduces the composite’s compressive strength. The reduction is caused by the remained polyurethane material on the surface of the remolded aggregate, which reduces its bond strength with the new polyurethane material. Aiming at this issue, this study applied the ethylene-vinyl acetate (EVA) to enhance the bond performance between the polyurethane and remolded sandstone. The test results indicated both the unconfined and triaxle compressive strength of the polyurethane composites were enhanced with the added EVA content. Furthermore, the durability performance of the EVA-modified composites were examined through freeze-thaw and wet-dry cycle tests. The test results indicated the EVA could enhance the polyurethane composites’ resistance to both wet-dry and freeze-thaw cycles. Overall, the modification with EVA can compensate for the strength loss of polyurethane composites because of the applied remolded aggregate and enhance its sustainability. The demolishing of the aged infrastructure has led to numerous construction waste, which has led to severe environmental burden , includiCurrently, polyurethane is widely applied in construction due to its novel mechanical performance , water rOne major obstacle prohibiting the wide application of the recycled aggregate is that the remained binder on its surface  can deteAnother type of solution is to modify the binder material for the mixture design optimization. Currently, the addition of superplasticizer ,41, replBesides the study on bonding performance, the investigation on the durability performance of the concrete with recycled concrete aggregate has also been widely conducted . The freAs mentioned above, currently the investigation and understanding of the recycled polymer concrete aggregate are quite limited. A detailed experimental investigation was conducted in this study to fill this knowledge gap. This study first examined the mechanical and durability performance of the original polyurethane-based composites incorporating the remolded sandstone aggregate. Then the strategy of modifying binder material was adopted for the performance enhancement. The original polyurethane was modified using the EVA content in this study, and the influence of the EVA content on the mechanical performance was then conducted with the unconfined and triaxle compressive tests. Furthermore, the influence on durability performance was also investigated by the wet-dry and freeze-thaw tests. The logic structure of the whole paper is demonstrated in The raw material for the sample preparation includes the collected Pisha sandstone from the field site and the W-OH type hydrophilic polyurethane. The original Pisha sandstone sample was collected from the Huangpu River Basin, Inner Mongolia, China, where the water erosion and soil loss is a long-term issue. The former studies indicated that the polyurethane could help to stabilize the fragile Pisha sandstone ,68. HoweThe W-OH type polyurethane has been used for repairing the concrete materials in the former study , which wThe first step is to prepare the polyurethane composites with original Pisha sandstone. The ready-prepared W-OH solution was quickly mixed with the sieved Pisha sandstone (No. 8 sieve size) during the preparation and the mass ratio between the sandstone and W-OH solution is selected to be 4:1 based on the filed experience . To inveThe next step is to obtain the remolded Pisha sandstone aggregate. The prepared polyurethane composites with original Pisha sandstone first went through 12 wet-dry cycles and then were manually cracked to obtain the remolded Pisha sandstone particles. This process simulated the natural degradation of the polyurethane-based composites and the freeze-thaw cycles were applied based on the protocol shown in In the field construction, the remolded and cracked Pisha sandstone/W-OH composites are re-solidified with the W-OH polyurethane to resume its water conservation ability . To simuAs the remained W-OH polyurethane on the surface of the remolded Pisha particle can deteriorate the performance of the remolded Pisha/W-OH composites, the modification on the W-OH was conducted by using ethylene-vinyl acetate (EVA) based on the former research results . Three rThe scanning electron microscopy was first conducted to examine the morphology difference between the original and remolded Pisha sandstone particles. The particles were coated with a 20 μm carbon layer before the examination.Besides the microscale characterization, the macroscale performance evaluation was also conducted, including the unconfined and triaxle compression tests. The unconfined compression test was conducted with the prepared cylinder samples in To better understand the sustainability of the Pisha/W-OH composites in the field condition, the durability tests were conducted for the prepared Pisha Sandstone/W-OH composites, including the freeze-thaw and wet-dry cycle tests. The infrastructure in Inner Mongolia goes through frozen temperatures in the winter and dry conditions in the summer season, respectively. The field examination also indicated the freeze-thaw cycles and wet-dry cycles are the major durability threats to the long-term performance of the infrastructure . Hence tThe measured unconfined compressive strength for the five type samples in The further compressive tests were then conducted with the Remolded Pisha sandstone/W-OH composites. The crushed samples and the test setup are shown in The triaxle compressive tests were further conducted with the remolded Pisha sandstone, original Pisha sandstone/W-OH composites, and remolded Pisha sandstone/W-OH composites separately to better understand the compressive performance under confining pressure. The triaxle compressive tests were conducted under the unconsolidated-undrained condition and the confining pressure  was selected based on the local crustal stress condition. The obtained stress–strain relationship for the remolded Pisha sandstone is shown in In this study, the stress when the axial strain reaches 15% was defined as the failure stress based on the recommendation in the reference . The comThe results in The examined compressive strength results for the samples re-solidified with EVA modified W-OH is demonstrated in Besides the performance evaluation on mechanical performance, further studies on the durability performance of the EVA modified W-OH composites were also conducted. Based on the local climate condition in Inner Mongolia, the durability performance under wet-dry and freeze-thaw cycles were examined. The evaluation was conducted by comparing the unconfined compressive strength before and after the durability tests as shown in Furthermore, the triaxle compressive tests were conducted for the EVA modified W-OH composites. The obtained results are shown in σ3 is the confining pressure value (kPa), and ε1 is the axial strain.To better understand the influence of confining pressure and remolding on the stress–strain performance of the composites, the Duncan–Zhang model was applied for the constitutive analysis of the Pisha sandstone composites as shown in Equation (1).One example of the fitted results based on Equation (1) is demonstrated in ε1→∞, (σ1 − σ3)ult can be represented with 1/b. The destruction ratio Rf can be further defined as shown in Equation (2). According to the relevant literature [Rf is generally between 0.5 and 1. In summary, the destruction ratio Rf of remolded solidified body, the model parameters a, b, the ultimate deviatoric stress and the destructive stress are shown in It can be known from Equation (1) that when terature , the desFurther studies were conducted for the morphology analysis of the original and remolded Pisha aggregate. The examination was conducted with SEM and the results are shown in (1)The remained polyurethane material on the surface of the remolded sandstone aggregate can enhance its internal friction. The samples with a higher amount of remained polyurethane can have higher compressive strength under the triaxle test.(2)The remained polyurethane material can reduce the unconfined compressive strength of the polyurethane composites containing remolded aggregate. The reduction is caused by the poor bonding between the remained polyurethane on the remolded aggregate surface and the new polyurethane material. The strength loss can be partially compensated with a higher concentration of polyurethane solution.(3)The modification with EVA can fully compensate for the strength loss of the polyurethane-based composites due to the applied remolded sandstone aggregate.(4)The EVA content can enhance the resistance to both freeze-thaw and wet-dry resistance of the polyurethane-based composites. The optimized EVA content based on mechanical and durability performance is 10m% based on the polyurethane content.This study investigated the mechanical and durability performance of the polyurethane composites with remolded sandstone aggregate. To compensate for the strength loss due to the added remolded aggregate, the EVA content was applied for the modification of the W-OH polyurethane. Then the unconfined and triaxle compressive tests were conducted to evaluate the mechanical performance tests. The durability under wet-dry and freeze-thaw cycles were also investigated. The major conclusion of this study are shown below:In the future, the research team aims to further apply the research findings in field construction to resolve the environmental burden because of the accumulated remolded Pisha sandstone and improve its resistance to environmental loadings. Furthermore, the field examination will help to identify the possible limitation of the proposed protocol and point out further research needs.