This difference is significant, especially considering the size of the rodent brain, a major research model in neuroscience. Our review will focus on the utilization of red light-operated optogenetic tools in neuroscience. We first outline the advantages of red light for in vivo studies. Then we provide a brief overview of the red light-activated optogenetic proteins and systems with a focus on new developments in the field. Finally, we will highlight different tools and applications, which further facilitate the use of red light optogenetics in neuroscience.Optogenetics, a field concentrating on controlling cellular functions by means of light-activated proteins, has shown tremendous potential in neuroscience. It possesses superior spatiotemporal resolution compared to the surgical, electrical, and pharmacological methods traditionally used in studying brain function. A multitude of optogenetic tools for neuroscience have been created that, for example, enable the control of action potential generation via light-activated ion channels. Other optogenetic proteins have been used in the brain, for example, to control long-term potentiation or to ablate specific subtypes of neurons. In  To get to this goal, researchers try to manipulate the function of a specific cell type within a specific brain structure during a specific time, while maintaining the rest of the brain as intact as possible. For this purpose, the spatiotemporal precision of optogenetics is superior compared to traditional research methods in neuroscience. The temporal resolution of optogenetics is dependent on light exposure . The spatial resolution is a combination of gene technology and the accurate focusing of the light on the target. Gene technology ensures the expression of the optogenetic system in the specific cells and the localization in targeted cellular compartments  can cause similar problems. PBM is a field that applies low-power red light illumination for therapeutic purposes. The mechanisms of PBM are still under debate, but are possibly related to mitochondrial enzymes, the production of reactive oxygen species, and endogenous red light-sensing proteins . Outsidein vivo models in broad utilization in neuroscience  in the target. In principle, actuators without a need for an extrinsic chromophore would be ideal, but the existing actuators with intrinsic chromophores utilize only strongly scattering and phototoxic UV light . Most ofoscience .in vivo experiments in most animal models  . DifferePhytochromes, however, are photochromic proteins, that is, they can be shuttled between active and inactive conformations by different wavelengths of red light . The phoCyanobacteriochromes have been utilized relatively little as optogenetic actuators compared to the other two red light-sensing actuator classes described above. CBCRs are photochromic relatives of the phytochromes, as they are composed of a singular GAF domain and bind a bilin chromophore . The smaOne important way to improve the utilization of red light in optogenetics is to gain more knowledge about the actuator proteins. New knowledge can then be utilized by genetically modifying the protein for more desirable attributes, like lower dark activity. Novel actuators and binding partners can also be found from nature, which can offer unprecedented options for optogenetic control.New knowledge has been gained on the structure of red light-sensing opsins  and the Different dimerization-based localization systems  are an iFor red light-controlled heterodimerization systems, the development of binding partners for phytochromes and CBCRs is crucial for attaining improved optogenetic systems. The first systems were based on the plant phytochrome B and its binding partner Phytochrome-Interacting Factor (PIF) . These sRhodopseudomonas palustris (RpBphP1) and its binding to PpsR2, suffers from a large size and self-oligomerization . Therefore, their activity is also sustained longer, compared to the QPAS1 system  more specific expression of the optogenetic actuators in the desired brain cells, and (2) more accurate manipulation of the system in the brain.In this section, we are taking a closer look at different methods that have improved or could improve the future optogenetic research with red light. Technical advancements in closely related fields, like robotics, imaging, and biochemistry, have made optogenetics a more and more applicable research approach in the field of neuroscience . The corA precise injection of a viral vector to a certain brain area is the main way to deliver the optogenetic system to the target cells. Viral vectors are replication-deficient viral particles, which can carry the DNA of the system into the target cells by infecting them. Injection protocols are constantly evolving to ensure accurate and safe delivery. For example, imaging dyes and magnetic resonance imaging (MRI) are used to ensure the accuracy of the injection . At the in vivo targets  lenses are routinely utilized for this purpose in neuroscience . In pracThe simultaneous use of other neuroscientific research applications can also disrupt illumination. The electrical activity of the brain is one of the fundamental parameters monitored in neuroscience. Combining optogenetics and electrophysiology enables simultaneous manipulation and recording of neural activity. Intracranial EEG provides better sensitivity and precision compared to the traditional electrophysiology methods . For thiFor topical parts of the brain, transparent intracranial EEG probes have been developed to be compatible with optogenetics . For exaThe first microwell high-throughput method for optogenetics has the potential to streamline future research. The LED-platform, optoPlate-96, enables a simultaneous and independent control of 96 3-color optogenetic experiments in 96- or 384-well plates. The system has been used in a two-system study of proliferation and survival-signaling pathways with the plant phytochrome-based OptoSOS system ; optoPlaDrosophila melanogaster larvae olfactory neuron activation by Chrimson has been visualized in the neurons by two-photon calcium imaging  have been one of the major improvements for optogenetic illumination . UPNC ar systems .Caenorhabditis elegans (Upconversion nanoparticles have other interesting characteristics which can be helpful in future research. For example, they have been successfully utilized as transfection vectors for an optogenetic apoptosis system without any transfection agents. In the same study, mouse tumors treated by the system have been monitored by an MRI based on the nanoparticles . UPNC ha elegans .The penetration of light into biological tissues is still relatively limited for larger animal models, like non-human primates. The optogenetic manipulation of structures deep in the primate brain is not possible without an intracranial probe, not even with NIR light . X-rays Besides the advances in transfection and illumination, various other methods have facilitated the use of red light in optogenetics. Data-driven approaches and simulations are just one example: red-shifted opsins have been found through machine learning-based data mining, and the photocycle of Chrimson has been theoretically optimized through a mathematical model . Similarin vivo to decrease the tumor size of mice (Heat-responsive promoters could be another tool to be utilized. They are parts of DNA that can bind heat-activated transcription activators, then activate the gene transcription. They have been utilized with the NIR light absorbance of photothermal-converting nanoparticles, which convert light to heat. In novel systems, an HSP70 promoter has been utilized  of mice . The ear of mice . Its sim of mice . SimilarDifferent platforms have also created new opportunities for red light-based optogenetics. Microfluidic biochips have been used to study axon development. There, a small 3D gel environment on the chip has enabled the co-culturing of motor neurons with main peripheral glial cells, Schwann cells. The opsin activation of the motor neurons has increased the axon growth and myelination by the Schwann cells .in vivo but could be an interesting tool for the research of Parkinson’s disease (An optogenetic bioimplant has also been created . The imp disease .in vivo. Consequently, the cone cells formed synapses with the natural preceding signaling cells of the visual pathway. Per the natural ON/OFF pathway of the signal transmission of sight, natural cone cells constantly inhibit their preceding signaling cells in the dark, and light inhibits this constant inactivation. Here, the natural signaling cells were activated after the inactivation of the modified cone cells by red light-induced Jaws activity (in vivo functions may be restored through the transplantation of red light optogenetic cells.Organoids are organ-mimicking multicellular 3D structures. Retinal organoids have been utilized for optogenetic vision restoration in mice by activity , 2021. TIn our review, we have focused on the current state and advancement in red light optogenetics in neuroscience. We have outlined the physical and biological properties to be considered regarding illumination, and we address the advantages of red light for the light penetration problem. We have also reviewed the current state of the research on red light-sensing optogenetic actuators. Several interesting optogenetic systems have recently been introduced, and we are keen to see their future applications. Lastly, we have highlighted different methods that support the future of optogenetic research. The methods have been shown to originate from a multitude of closely related fields of science with the primary focus on the improvements in transfection and illumination methods. Overall, we hope that our review will facilitate the use of red light for optogenetics in neuroscience.We would finally like to leave the reader with a list of hints and suggestions for future studies, which is based on the reviewed literature:•Utilize the better tissue penetration of red light in transcranial illumination.•Apply the photochromaticity of phytochromes and CBCRs for reversible biological events.•Improve existing heterodimerization systems with the recent smaller binding partners.•Apply the recently found opsin types for novel optogenetic applications.•Utilize the two-photon absorption of bacterial phytochromes for better tissue penetration.•Create new multichromatic systems with a wider range of actuators and wavelength ranges.•in vitro to neuroscientific applications in vivo.Transfer the red light-sensing optogenetic systems published •Consider nanoparticles as a research tool and collaborate with someone with knowledge of their production and use.•in vitro platforms to streamline optogenetic studies.Use high-throughput •in vivo studies.Consider the possibilities of optogenetic neural bioimplants for •Utilize the heat produced by the red light in heat-responsive approaches.•Favor the use of one-vector approaches with smaller proteins, homodimerization systems, and linked opsins.•Consider methods that help injection or implantation in the brain, like robotics or MRI.•Prefer the use of transcranial and topical intracranial approaches in recording and imaging of the optogenetic effect, which preserves the brain under study.•Turn computer-based results about red light-driven systems into actual applications.•Note the possible effects of endogenous opsins and PBM on the optogenetic experiments.•When plant phytochromes and CBCRs are used in the brain, ensure their chromophore availability.•Facilitate the simultaneous use of EEG and optogenetic applications in the deep brain by morphing intracranial LEDs with intracranial transparent EEG probes.•Expand the minimalistic optogenetic toolbox of CBCRs to benefit from their small size and photochromatic activity.KL, HT, and MN designed and wrote the manuscript. All the 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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Persistent immune activation and dysfunction induced by infectious agents may contribute to long term comorbid conditions in individuals exposed to these pathogens. Even during successful antimicrobial treatment, increased levels of inflammation and immune cell activation and inappropriate immune cell migration and retention in tissue sites may contribute to tissue damage and end organ disease . Understanding why some populations infected with a pathogen are able to regulate their immune responses and limit their inflammatory consequences, while other individuals may have exacerbated and persistent immune responses even during suppressive therapy, may provide insights for development of complementary immune-modulatory therapies that may reduce inflammation and morbidity and mortality in these groups. The Research Topic highlights some of these issues.via various mechanisms. The problem is that although some forms of this immune activation are beneficial for the eradication of the microbial agent, others may be toxic, not only in the short term but also in the long term. It is therefore important to understand these pathogenic pathways, inasmuch as they may persist even under efficient antimicrobial therapy.Any infection induces the activation of the human immune system Some microbial components may activate the complement and/or the coagulation system and thereby start an inflammatory reaction. Phagocytic cells will be recruited into infected tissues, and activated to engulf the infectious agent in order to neutralize it. In the meantime, immune and non-immune cells detect the presence of pathogen-associated molecular patterns, triggering a danger signal that also fuels inflammation and promoting the initiation of the adaptive immune response, ideally, resulting in a cellular and humoral immune response targeting specific microbial antigens. Natural killer cells and cytotoxic T cells will identify infected cells and destroy them. All of these types of immune activation may contribute to the elimination of the invader. Yet, besides these desirable effects, the microbial agent may also cause side effects with potential pathogenic consequences Figure 1First, many infectious agents have developed the means to evade defenses and subsequently promote immune dysfunction. A master of this gameplay is the human cytomegalovirus (HCMV). HCMV downregulates the density of HLA classes I and II at the surface of the cells it infects  and intevia metabolic disorders. Thus, Human Immunodeficiency Virus (HIV) infection increases the level of oxidized LDL able to activate monocytes via Lectin-like oxidized LDL receptor-1  presenting residual viral load under ART. This profile is characterized by CD4+ T cell, monocyte, and endothelial activation. These data reinforce the hypothesis that low-level viremia could drive a specific form of immune activation in virologic responders. Many studies using the single copy assay of plasma viremia have shown that most patients have persistent plasma viremia in the range of 1-10 copies/ml despite being classified as fully suppressed by standard clinical monitoring assays  dynamically changed over time to reach a peak 3-4 weeks after symptom onset with a response lasting for an average of 112 days. They found that these responses were higher in patients with a severe condition.Immune activation may also impact the capability of mounting a specific immune response. Several studies explored the link between COVID-19 severity and the development of an efficient humoral immunity with contradictory results. Moreover, the question of antibodies as beneficial, neutral or harmful in SARS-CoV-2 infection remains controversial. Auma et al. resulting in at least partial or full restoration of circulating naïve CD4 T cells numbers. The importance of the size of the pool of these cells for control of future infections has recently been suggested as the cause of the age-related loss of control of SARS-CoV-2 infection in older patients  and chemokines .Last, All authors listed have made a substantial, direct, and intellectual contribution to the work and approved it for publication.PC was supported by MSDAvenir (DS-2016-0010).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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Detection of unknown malware and its variants remains both an operational and a research challenge in the Internet of Things (IoT). The Internet of Medical Things (IoMT) is a particular type of IoT network which deals with communication through smart healthcare  devices. One of the prevailing problems currently facing IoMT solutions is security and privacy vulnerability. Previous malware detection methods have failed to provide security and privacy. In order to overcome this issue, the current study introduces a novel technique called biserial correlative Miyaguchi–Preneel blockchain-based Ruzicka-index deep multilayer perceptive learning (BCMPB-RIDMPL). The present research aims to improve the accuracy of malware detection and minimizes time consumption. The current study combines the advantages of machine-learning techniques and blockchain technology. The BCMPB-RIDMPL technique consists of one input layer, three hidden layers, and one output layer to detect the malware. The input layer receives the number of applications and malware features as input. After that, the malware features are sent to the hidden layer 1, in which feature selection is carried out using point biserial correlation, which reduces the time required to detect the malware. Then, the selected features and applications are sent to the hidden layer 2. In that layer, Miyaguchi–Preneel cryptographic hash-based blockchain is applied to generate the hash value for each selected feature. The generated hash values are stored in the blockchain, after which the classification is performed in the third hidden layer. The BCMPB-RIDMPL technique uses the Ruzicka index to verify the hash values of the training and testing malware features. If the hash is valid, then the application is classified as malware, otherwise it is classified as benign. This method improves the accuracy of malware detection. Experiments have been carried out on factors such as malware detection accuracy, Matthews’s correlation coefficient, and malware detection time with respect to a number of applications. The observed quantitative results show that our proposed BCMPB-RIDMPL method provides superior performance compared with state-of-the-art methods. The Internet of Things (IoT) is an extensive network of smart, internet-connected devices that automatically sense and collect data from various environments. With the rapid growth of IoT technologies, the detection and analysis of malware is a significant concern in medical application systems. Malicious applications may damage android IoT devices. Therefore, increased attention must be paid to the detection of these applications to stem privacy leakage and property loss. Several methods have been developed to detect malware, which are discussed here.A highly scalable malware detection framework, enabled for software-defined networking (SDN), which was a hybrid convolutional neural network with long short-term memory (CNN-LSTM), was developed for the Internet of Medical Things (IoMT) . LSTM waKumar et al. (2019) devised a novel method that integrated machine-learning techniques and blockchain to detect malware in Android IoT devices . The malJahromi et al. (2020) introduced a stacked LSTM method that improved malware detection performance . The desTwo different methods were developed for malware detection. The Robust-NN was designed with the integration of a convolutional neural network and 1- nearest neighbours (C4N) for enhancing the accuracy . HoweverTakase et al. (2020) used values that were extracted from the processor to detect malware. The designed mechanism was used to categorize malware or benign programs with the aid of processor information to improve security, but no hash-based malware feature analysis was performed to minimize the time consumption . FinallyMalware detection is one of the most important threats in IoT. Machine learning is one of the most effective methods employed to detect malware in an IoT environment. Previous work has shown that the malware detection method has not yet solved the two-fold concern that malware must be detected accurately but as quickly as possible. Previous studies have shown that this method takes more time to classify malware detection and does not possess the expertise to effectively and timely handle the massive numbers of newly discovered malware. To overcome this issue, the current BCMPB-RIDMPL technique has been introduced.The objective of the proposed technique is as follows:To enhance malware application detection with lesser time consumption, the BCMPB-RIDMPL technique is introduced;To minimize the malware detection time, the BCMPB-RIDMPL technique uses Point biserial correlative feature matching to select the relevant feature and remove the unnecessary malware features;To generate the hash value with maximum security, the Miyaguchi–Preneel cryptographic hash-based Blockchain is applied in the BCMPB-RIDMPL technique;To match the hash value, the Ruzicka similarity index is applied for categorizing the malware and benign applications in BCMPB-RIDMPL.The BCMPB-RIDMPL technique is shown to improve the detection of malware applications through the choice of the processes of feature selection, blockchain technology, and classification;The method is shown to match the point biserial correlative feature to select the relevant feature and remove the malware;The novelty of the point biserial correlation coefficient is employed to estimate the correlation among the features. The maximum correlations among the features are chosen and other features are eliminated. It is used for minimizing the dimensionality of data and malware detection time;The Miyaguchi–Preneel cryptographic hash-based blockchain is applied to create the hash value for each selected feature;The novelty of the blockchain technology Miyaguchi–Preneel compression function is used for creating the hash value. This helps to ensure security by avoiding unauthorized access;The novelty of the Ruzicka similarity index is used to verify the hash value of malware and other test features and classifies malware and benign applications;Lastly, the paper explains the extensive experimental evaluations that have been performed in various performance metrics to highlight the benefit of the proposed BCMPB-RIDMPL method over conventional classification techniques.The present work explains the development of a novel biserial correlative Miyaguchi–Preneel blockchain-based Ruzicka-index deep multilayer perceptive learning (BCMPB-RIDMPL) technique. The research contributions described in this paper are summarized here:The article is organised into five different sections as follows. Das et al. (2019) analyzed the different types of malware detection approaches that have been applied to improve the security of the IoT/IoMT environment . DiffereAn advanced ensemble learning (MTHAEL) method was developed for robust IoT malware threat detection . The desLei et al. (2019) developed a scalable and event-aware android malware detection method. The neural network was used for extracting high-level semantics. The softmax classifier was employed to create the prediction, but the deep-learning model was not implemented for accurate malware detection . A sub-cGuizani and Ghafoor (2020) identified a software-based architecture for malware detection to improve the security performance of IoT devices . The desA machine-learning-based visualization scheme that was developed by Liu et al. 2020) for malware identification could not be applied to a wide range of applications in machine learning and computer security , but the20 for maA deep learning-based ensemble learning detection framework was introduced by Ma, et al. (2019) for API fragments , but theThe IoMT is a network of connected wearable medical devices and medical systems. It facilitates a variety of healthcare services to minimize healthcare expenditure, offers timely medical responses, and increases the quality of medical treatment. In recent years, numerous works have been designed for malware detection. Accurate malware detection is a challenging task, since the machine learning techniques use the entire feature for classification, therefore making it infeasible and inaccurate. Hence, the dimensionality of the dataset needs to be minimized for accurate malware detection with minimum time consumption. In order to overcome the issue, a BCMPB-RIDMPL technique is introduced. The proposed technique aims to enhance the accuracy of malware detection with minimum time consumption and false-positive rate. The BCMPB-RIDMPL technique performs feature selection and classification, using Point biserial correlative feature matching to identify the relevant features for accurate detection. The selected relevant features are used to classify and detect the malware.Medical devices are more susceptible to many security threats and attacks than other network devices. Apart from enabling access to sensitive medical data, this application malware destroys the devices and affects the hospital network. Attacks on these connected devices also cause major physical damage. Therefore, the main aim of the research explained in this paper is to underline the need for security research in the field of IoMT and to address security and privacy concerns through the introduction of a novel BCMPB-RIDMPL technique.The schematic structure of deep multilayer perceptive learning is shown in Point biserial correlative feature matching is a statistical technique that is used to choose the relevant features and to remove unnecessary features from high-dimensional space. The mapping process reduces the dimensionality of the datasets. The dataset comprises the malware features The correlation between the features is measured as given in Equation (1):Here, In Equation (2), In the second hidden layer, blockchain technology is applied to generate the hash for the improvement of security. Miyaguchi–Preneel cryptographic hash-based blockchain technology is a distributed model that stores the malware features in each block. The basic structure of blockchain technology is shown in The blockchain comprises a number of blocks that construct a chain. Each block comprises a block header, timestamp , In Equation (4), These hash values are stored in the blockchain. The first part of the block header stores the hash values of all data. The second part of the block stores all static and dynamic characteristics of the malware such as suspicious APIs, permissions, events, calls, and so on. This feature information in the block is announced for all the users to predict the malware with higher accuracy and minimum time consumption.After the information is stored in the blockchain, the classification process to detect malware applications is performed in the third hidden layer. When doctors download the application files, first they verify the hash values of malware features. The hashed information regarding malware features is verified against the test malware features. If these two hash values are matched, then the applications are classified as malware. Otherwise, the applications are classified as benign. The hash value verification is done with the help of the Ruzicka similarity index. The Ruzicka similarity is calculated as given below: In Equation (5), Algorithm 1: Biserial correlative Miyaguchi–Preneel blockchain-based Ruzicka index deep multilayer perceptive learning.Input: Dataset, malware features Output: Improve the malware detection accuracyBeginStep 1: Collect the malware features [input layer]Step 2: For each feature [hidden layer 1]Step 3: Measure correlation Step 4: Select highly correlated featuresStep 5: Remove other featuresStep 6: End forStep 7: Construct blockchain [hidden layer 2]Step 8: For each selected featureStep 9: Partition into k message blocks Step 10: For each block Step 11: Generate a hash value Step 12: End forStep 13: Obtain the final hash Step 14: End forStep 15: Store the hash in the blockchain Step 16: Perform hash verification [hidden layer 3]Step 17: Measure similarity Step 18: If . The dataset contains 129,013 application packages, among which 123,453 are benign application packages (.apk) and 5560 are malware android application packages. The dataset comprises comma-separated value (CSV) files. Among the multiple malware features, relevant features were selected for classification. The efficiency of the NGBFSEII-BCP method is determined in terms of malware detection accuracy, the Matthews correlation coefficient, and malware detection time. The hardware specifications are shown in A novel Drebin dataset originally developed by the Institute for System Security at the Technical University of Braunschweig, Germany, was used to conduct the experiments to identify malware. This dataset was taken from In this section, the experimental results of the tests on the BCMPB-RIDMPL technique and the state-of-the-art existing hybrid CNN-LSTM  and multThe malware detection accuracy  is definThe Matthews correlation coefficient  is basedThe time taken to detect malware is defined as the amount of time that passes between data input and detection by the algorithm of benign or malware applications . The oveThe shorter detection period shown by the BCMPB-RIDMPL technique, which is displayed graphically in The area under the curve (AUC) is a measurement of the performance of the results of the classification of true positives and false positives. A Receiver Operator Characteristic (ROC) curve or the Receiver Operating Characteristic curve refers to the graph indicating the performance of the BCMPB-RIDMPL technique. The AUC-ROC curve is used to solve the binary classification issue. The AUC curve plots two metrics, namely true positives and false positives. Area Under the Curve (AUC) is used to compute the ability of a classifier to distinguish between classes. It is used as a summary of the ROC curve. The ROC curve plot illustrates the relationship between true positives and false positives. The AUC-ROC curve provides a better performance of the model at distinguishing between the positive and negative rate in malware detection. The performance of AUC curve of BCMPB-RIDMPL technique and existing methods hybrid CNN-LSTM or multi-kernel SVM systems is illustrated in Performance measurement is an essential task in Machine Learning. AUC-ROC curve  is used The open and widespread environment of the IoMT, which offers high-end digital advantages and involves human lives, creates huge challenges to protect the data from evolving cyber threats, attacks, and vulnerabilities. To address this challenge, we have proposed a highly scalable and efficient malware detection technique. The BCMPB-RIDMPL method initially selects the number of features to reduce the complexity of malware detection. After this feature selection, a hash value is generated through the use of the Miyaguchi–Preneel compression function, and the results are stored in the blockchain. Finally, the Ruzicka similarity index is applied for efficient and timely detection of sophisticated IoMT malware with higher accuracy than is shown by techniques currently in use. A comprehensive experimental estimation of the method has been carried out with consideration of different performance factors such as malware detection accuracy, false-positive rates, and malware detection time. The analysis shows that the proposed BCMPB-RIDMPL technique outperforms the existing classifiers, with higher malware detection accuracy by eight percentage points and the Matthews correlation coefficient by twenty three percentage points, and a shorter detection time by twelve percentage points.


The COVID-19 pandemic prompted the development and implementation of hundreds of clinical trials across the USA. The Trial Innovation Network (TIN), funded by the National Center for Advancing Translational Sciences, was an established clinical research network that pivoted to respond to the pandemic.The TIN’s three Trial Innovation Centers, Recruitment Innovation Center, and 66 Clinical and Translational Science Award Hub institutions, collaborated to adapt to the pandemic’s rapidly changing landscape, playing central roles in the planning and execution of pivotal studies addressing COVID-19. Our objective was to summarize the results of these collaborations and lessons learned.The TIN provided 29 COVID-related consults between March 2020 and December 2020, including 6 trial participation expressions of interest and 8 community engagement studios from the Recruitment Innovation Center. Key lessons learned from these experiences include the benefits of leveraging an established infrastructure, innovations surrounding remote research activities, data harmonization and central safety reviews, and early community engagement and involvement.Our experience highlighted the benefits and challenges of a multi-institutional approach to clinical research during a pandemic. Excellence in the development and execution of clinical trials is never more critical than during a pandemic. Clinical trials targeting the pandemic are necessary to demonstrate the safety and efficacy of lifesaving prevention measures, treatments, and vaccines. During a pandemic, the usual delays and inefficiencies that often plague clinical trials should not be tolerated by sponsors or the general public. In the midst of daily case counts and a rising number of widely reported, attributable deaths, delays, and inefficiencies in clinical trials are measured by the lives lost. Thus, operational excellence in the conduct of clinical trials becomes paramount. Simply stated, trials are an even more critically “essential activity” in a pandemic. Since it was established in 2016, the National Center for Advancing Translational Sciences (NCATS)-funded Trial Innovation Network (TIN) has focused on operational innovation and collaboration to support successful multicenter clinical trials within the Clinical and Translational Science Awards (CTSA) Hub consortium, addressing a wide range of diseases and health conditions [The TIN is a collaborative initiative within the NCATS CTSA program that consists of three key partners: the CTSA Program Hubs, the three Trial Innovation Centers (TICs), and the Recruitment Innovation Center (RIC) Fig. . The TINEach of the three major TIN components plays a key role in the functions of the TIN. The CTSA Program Hubs are a network of 66 medical research institutions that collaborate locally and regionally to catalyze innovation in training, research tools, and processes. As the key partner of the TIN, the CTSA Program Hubs: (1) encourage faculty and investigators at each Hub institution to generate ideas for trials and studies; (2) provide input before protocols are implemented; (3) help to efficiently identify study sites with sufficient resources and patient populations; (4) support and further develop the essential efforts of their local teams in executing multicenter clinical trials; and (5) create a culture in which key stakeholders play unique and important roles and ultimately work together to build a national system to conduct clinical trials better, faster, and more cost-effectively.Initial Consultations: Initial consultations, which are provided for all submitted proposals, offer a platform for the submitting study team to share the details and vision of their proposal with the TICs, the RIC, and the NCATS. During the consultation, an assigned TIC, the RIC, and NCATS provide input to the submitting team in multiple areas and explore potential collaboration opportunities  were not always reliable in projecting which potential sites would have the greatest numbers of eligible participants. This number changed quickly at sites; and at some sites was in near-constant flux.3.Many potential clinical trial sites struggled to identify efficient methods to execute the logistics of clinical trial site activation and execution, including contracting, site location, assessment of available staff, consenting participants, and the safe implementation of study procedures. This was particularly true for outpatient COVID positive participants.4.The burden of COVID-19 has disproportionately impacted Black, Hispanic/Latino, Indigenous people, and individuals with limited English proficiency (LEP) –7. HistoAs the COVID-19 pandemic spread across the USA, there arose a critical need for clinical trials targeting both preexisting and newly developed therapeutics. Approximately 250 interventional clinical trials were posted on the clinicaltrials.gov website by May 30, 2020 [The TICs and RIC adapted to address these challenges in several ways. The TICs and RIC developed processes to triage the increased number of COVID-related proposals. Discussions of each potential study focused early on trial feasibility and the ways in which the trial would complement or compete with other trials that were already being performed. Given the changing geographical landscape of the focus of the infection, the consulting teams advised investigators to place EHR-based cohort assessments in context for the selection of clinical sites.The TIN took numerous steps to address the logistical challenges of conducting clinical research during a pandemic. The challenges of in-person participant recruitment and follow-up offered an ideal opportunity for innovation using direct-to-patient, remote methodologies. For example, one TIC and the RIC assisted faculty at Medical University of South Carolina in the development of a fully remote, observational cohort study that aimed to examine the outcomes of infants who were exposed to COVID-19 by enrolling mother-infant pairs. The study engaged clinical sites to advertise participation to potential participants, but the participants self-enrolled via a study website using electronic consent. All follow-up occurred remotely via questionnaires and remote interviews. The TICs and RIC also helped multiple trials transition to electronic consenting procedures or transition from being in-person to becoming fully virtual.The RIC leveraged one of its flagship programs for connecting with the community at large: community engagement studios (CE studios), a model for gathering community member input on research . The CE The most important advantage the TIN had in its response to the COVID-19 pandemic was its pre-established infrastructure and the fact that the TIN’s mission was not restricted to supporting one disease. This infrastructure was critical because: (1) communication lines were already in place among a vast network of academic institutions capable of implementing clinical trials; (2) there existed a central body and mechanism for the development and review of proposals and triage facilitation and prioritization; (3) there were experienced coordinating centers familiar with rapid start-up and site activation. The TIN had already leveraged this infrastructure to operationalize coordination of the Helping to End Addiction Long-term (HEAL) Pain Management Effectiveness Research Network (ERN). This multisite research cooperative is leading and implementing multiple clinical trials to address the opioid epidemic by testing alternative strategies for the prevention and treatment of acute and chronic pain. Pivoting from the opioid epidemic to the COVID-19 pandemic allowed the TIN to leverage existing tools and strategies but also highlighted some challenges unique to the pandemic. For example, the TICs and RIC responded to a consultation from Washington University to engage in the ACTIV-1 trial, a phase 3 clinical trial that will enroll approximately 2,000 adults in the USA and Latin America hospitalized with moderate to severe cases of COVID-19 . The conHowever, multiple challenges were encountered following the speed of initial site activation. Some challenges were specific to the pandemic. These challenges included a reduced availability of study coordinators and the presence of other studies competing for limited resources, such as information technology resources for electronic medical record builds and review of contracts. Some challenges existed independent of the pandemic itself but were especially impactful due to the pandemic-related need for speedy trial completion. For example, many study sites required start-up activities  to occur sequentially rather than in parallel. Efficient agreement on contract language was extremely variable between sites. Some of this variation was attributed to unique aspects of flow down language placed in the master contract by the sponsor. In addition, even in the setting of single IRB review, many local IRBs require levels of additional review that delay activation. In fact, “local context review” results in considerable potential delay of activation in the single IRB review era. Site investigators often have little control over these issues, and the coordinating center lacks the ability to accelerate these processes.Because of its robust infrastructure, the TIN became a central reviewing body of a large number of COVID-related trial proposals, many of which were otherwise funded by either industry or separate funding agency sponsors and would not have had central oversight. This unique vantage point allowed the TIN to learn from each trial, incorporating successful strategies when applicable and foreseeing challenges with certain protocols. In large trials, for example, the TIN recognized the need for detailed and frequently planned interim analyses so that critical data such as baseline severity, comorbidities, and critical event rates could be reviewed at real-time intervals during the pandemic.Two TIN programs are in ongoing efforts to leverage cooperative activity across the CTSA Hubs by pooling individual participant data from small trials to produce an individual patient analysis of data across trials. A similar exercise occurring in real time is also being performed to compare, contrast, and combine safety data from multiple trials in real time to increase safety communication among autonomous trial DSMBs during the accrual period of trials.Piloting efficacy data pooling has focused on several inpatient trials that ended accrual in late spring because the pandemic slowed, and several peer-reviewed signals suggested a small or no benefit with the possibility of increased safety events in the active exposure arm. This effort has involved comparing individual trial data dictionaries, harmonizing data elements, developing cross-trial consensus on the prioritization of clinical hypotheses to analyze, development of a consensus on the statistical analysis plan, organizing an authorship and publication plan, and combining multiple limited data sets with protection of protected health information.The TIN DSMB Coordination (DSMBc) effort sought to create visualization and data reporting tools to enable the synchronized review of multiple studies by a single DSMB focused on a specific therapy using harmonized reports (hReports) . The DSMThe TIN sponsored numerous activities during the pandemic that supported dissemination of research-related activities. Examples include over 13 public-access TIN hosted Webinars and Open Forums related to COVID-19 related research activities and resources. One of these webinars held in March 2020 and attended by over 400 participants targeted self-service tools for eConsent, 21CFR Part-11 validation, and best-practice videos related to development and support of eConsent methods. Based on consultations performed during the pandemic, the RIC developed a COVID-19 Recruitment and Retention Toolkit which is publicly available. The TIN also supports a persistent messaging hub for approximately 200 local CTSA recruitment and retention experts. Communication on this messaging platform may include any topic related to participant recruitment and retention, but COVID-19 related discussions have been popular during the pandemic.Many of the TIN’s adaptations during the COVID-19 pandemic could be applied to non-COVID research. Remote research has multiple possible benefits, including added convenience for study participants, improved retention of participants, and reduced costs. The use of electronic consent should be considered for any study. The direct-to-patient approach to clinical research also allows for the recruitment of participants from rural and other communities that may not have access to the classic academic clinical research site.One important lesson from the COVID-19 pandemic is the need for the early engagement of the lay community. The alarming number of cases of morbidity and mortality related to COVID-19 in vulnerable populations makes the enrollment of affected groups in clinical trials a priority. The rapid pace of research during a pandemic can challenge principles of engagement, which focus on engendering trust and gaining buy-ins from communities. However, many CTSA Hubs had already built robust community engagement programs, which encouraged the community to understand research needs and meet these challenges. The CTSA program’s commitment to community engagement provided research teams at the Hubs the ability to consult with community research advisory groups who were already familiar with the ways in which research teams and community groups could work together to support clinical trials. The RIC team quickly shifted to virtual CE studios and completed eight CE studios focused on COVID-19 projects, with important lessons learned on conducting studies during the pandemic Fig. . In addiThe COVID-19 pandemic also offered a unique opportunity for building other new relationships with the community that we hope will become permanent. One example of such a relationship was proposed to the TIN as an initial consultation. The project, now funded by NICHD, links school leaders with CTSA sites to interpret emerging scientific evidence to keep children, teachers, and the community healthy and safe during the COVID-19 pandemic. The long-range vision for community engagement is that these relationships will become a foundation for further outreach and research that will positively impact public health.While the COVID-19 pandemic is ongoing at the time of this communication, thus limiting definitive conclusions and comprehensive assessment of the effectiveness of the TIN’s pandemic-related activities, the TIN’s early experiences have yielded several recommendations that might be applied to future pandemics. The following recommendations were produced as a collaborative effort among the leadership of the TICs and RIC, including multiple faculty members who also lead CTSA Hubs.1.Emphasize the essential nature of research during any pandemic.2.multisite clinical trial infrastructure that is prepared to respond to new health threats and can be quickly leveraged to develop and implement the most pivotal clinical trials. An efficient clinical trial network should not be freshly launched during a new pandemic; it should be well-practiced with a track record of success prior to the pandemic.The nation should invest in 3.Remote activities and a direct-to-participant approach can facilitate research at times when in-person, site-based activities are neither feasible nor preferred.4.Early recognition of the limits of non-pandemic clinical trial site assessment tools  and pivoting to new methods , can accelerate timelines and set realistic expectations for enrollment.5.Data harmonization should be an early focus. Early guidance regarding preferred definitions for primary and secondary outcomes would streamline clinical trial development and substantially improve the ability to interpret results across studies. Consortium level master protocols could enhance the cross trial harmony of subsequent data.6.data safety monitoring boards increases the relevance of smaller studies and the probability of observing important safety signals for therapeutics that are likely to become widely used.When possible, combining trial data and 7.Community involvement in study development is critical in building trust in scientific and medical activities and can have a long-lasting, positive impact on public health. Rapidly engaging marginalized communities during a pandemic requires community engagement infrastructure and prior investment in mutually beneficial community-academic partnerships.


Surveillance testing within healthcare facilities provides an opportunity to prevent severe outbreaks of coronavirus disease 2019 (COVID-19). However, the quantitative impact of different available surveillance strategies and their potential to decrease the frequency of outbreaks are not well-understood.We establish an individual-based model representative of a mental health hospital yielding generalizable results. Attributes and features of this facility were derived from a prototypical hospital, which provides psychiatric, psychosomatic and psychotherapeutic treatment. We estimate the relative reduction of outbreak probability for three test strategies  relative to a symptom-based baseline strategy. Based on our findings, we propose determinants of successful surveillance measures.Entry Testing reduced the outbreak probability by 26%, additionally testing once or twice weekly reduced the outbreak probability by 49% or 67% respectively. We found that fast diagnostic test results and adequate compliance of the clinic population are mandatory for conducting effective surveillance. The robustness of these results towards uncertainties is demonstrated via comprehensive sensitivity analyses.We conclude that active testing in mental health hospitals and similar facilities considerably reduces the number of COVID-19 outbreaks compared to symptom-based surveillance only.The online version contains supplementary material available at 10.1186/s12879-022-07075-1. Treatment and care facilities with intermediate to long-term treatment durations pose a setting in which active COVID-19 surveillance strategies are urgently required. This became apparent from reports of disastrous outbreaks in skilled nursing facilities . PsychiaSurveillance aims at the disruption of evolving infection clusters in order to halt the spread of infection. Existing COVID-19 surveillance strategies revolve around detection of infected individuals in order to isolate them and their close contacts. To this end, possible infections are commonly confirmed by polymerase chain reaction (PCR) tests . Yet, suHigh quality evidence about the benefits of surveillance testing is sparse. Mathematical modelling studies complement empirical evidence by conceptualizing the important aspects of the problem  and by iWe add to the available body of evidence by proposing an individual-based model representative of a prototypical psychiatric-psychosomatic hospital offering treatment to patients for extended periods of time. Our study aims at providing some generalizable key results with a robust quantification of their uncertainty. This is achieved by conducting a comprehensive set of sensitivity analyses of parameters and various structural assumptions presented in an easily accessible form.We simulated the propagation of infection and implementation of surveillance measures in a hospital  with 60 inpatients with an average duration of stay of 8 weeks and 80 staff members. The hypothetical clinics were initialized with fully susceptible populations whose dynamic evolutions were simulated in daily increments for a total simulation time of 100 days. The facility was modelled as a semi-closed environment: Propagation of infection within the clinic was treated as a closed system, but interactions with the environment outside of the clinic could introduce infected individuals into the clinic. Figure The infection dynamics were implemented in the model at the level of individual agents which represented individuals in the clinic population. Individual-based models offer a high flexibility and allow for incorporation of inter-individual heterogeneity and inherent stochasticity, such that they are well suited to model relevant features of the epidemiological dynamics realistically . The curThe disease progression was modelled structurally similar to a homogeneous stochastic SEIR-model , but extmentclass2pt{minim, i.e. the number of secondary cases caused by the respective primary cases [Variations in the natural history of the disease are not only manifested in the display of symptoms but also in the timing of the different disease states. It has been shown that accounting for stochasticity in these timings significantly affects the modelled spread of a virus . Consequry cases . For trary cases , 17, impTemporal variations of the infectiousness of agents at different stages of their disease were represented by time-dependent infectivity profiles . The infHeterogeneity in the transmission structure has been found to play a key role in infection spread, e.g. by application of infection models on networks  or age-sSurveillance measures are implemented to detect and prevent the spread of infection within the clinic. This is achieved by enforcing strict quarantine on individuals who display symptoms or individuals who were tested positive in screening measures, e.g. achieved by relocating the agent out of the clinic. Once an agent is quarantined, the agent was assumed to be non-infectious during the time of isolation. While this is likely not entirely realistic, this is a decent approximation in the light of the multitude of other, more critical modelling assumptions. The fundamental concepts of outbreak detection and containment represented a symptom-based baseline surveillance scenario which was common to all considered surveillance strategies. It comprised (i) isolation based on symptoms, (ii) case ascertainment via diagnostic testing, and (iii) subsequent contact tracing to isolate contacts at high risk of possible contagion due to previous contact with the index case.Isolation based on symptoms was modelled as a daily probability of isolating an agent in the symptomatic state (Abbott)  as emplomentclass2pt{minim, aimed at detecting the intrusion of the virus into the clinic at the entry point, in addition to baseline surveillance. To this end, patients which were newly admitted to the clinic or who returned from temporary absence were tested immediately when entering the clinic and five days after, which accounted for potentially long incubation times. The third and fourth strategy implemented regular testing of the clinic population on top of entry testing and baseline surveillance, i.e. testing every agent once weekly or twice weekly, respectively. These regular tests were simulated to be performed each Friday for once weekly testing and additionally each Tuesday for twice weekly testing. Considering that the result likely depends on slight variations in the incubation time or presymptomatic time for which exact knowledge about the distribution is sparse and constantly shifting, different testing days have not been analysed. As individual agents may refuse to participate in preventive testing measures, compliance to testing measures was defined as an additional agent property which was randomly assigned to each agent independent of their role with a certain probability given by the corresponding parameter. Non-compliant agents were not tested for strategies which imposed regular testing on the clinic population, i.e. for the third and fourth strategy. However, all agents were assumed to be compliant to isolation based on symptoms or a positive test result as this was the case in the actual clinic.Four different surveillance strategies were evaluated quantitatively: The aforementioned symptom-based baseline surveillance strategy in which testing is only initiated because of symptoms and three active surveillance strategies. Active surveillance strategies comprised preventive testing of the clinic population. The first investigated strategy was the symptom-based baseline surveillance. The second strategy, termed entry testingIn order to quantitatively evaluate the efficacy of the different strategies, suitable outcome measures were defined. The primary outcome measure of interest was the reduction of outbreak probabilities between two defined strategies. An outbreak was defined as The relative reduction of outbreak probability by entry, once weekly and twice weekly testing relative to the symptom-based baseline strategy is displayed in Fig. Implementing entry testing reduced the probability of an outbreak by 26% relative to the baseline only strategy, additionally testing of the clinic population once or twice weekly reduced the outbreak relative to the baseline strategy by 49% and 67%, respectively. The best guess outbreak probability reductions were mostly robust to variations of parameters and the large number of simulations conducted lead to narrow stochastic uncertainties. The sensitivity of the diagnostic test and compliance of the clinic population critically determined the efficacy of the strategy. Both of these parameters are not epidemiological quantities and can therefore be target for optimization in applications, which due to their large impact may lead to a considerable reduction in outbreaks. Epidemiological parameters with noticeable impact on the uncertainty of results were the reproduction number (R0), the probability of contracting an infection outside of the clinic (OutsideInfection) and the timing of the peak of infectiousness (PeakInfectiousness). An analysis of best-case and worst-case parameters for outbreak probability reduction provides a span of results of 8% to 61% for entry testing, 22% to 86% for once weekly testing and 37% to97% for twice weekly testing.In order to assess the efficacy of the symptom-based baseline surveillance, it has been compared to a scenario with no surveillance in Additional file Practical feasibility of the strategies was assessed by analysing the secondary outcomes, i.e. the amount of tests conducted per day and the amount of individuals in quarantine on a given day. Since testing twice weekly was the most extensive testing strategy proposed, these outcomes have been analysed in a full 1-way sensitivity analysis. The results are visualized in Additional file The test-to-result delay of diagnostic tests differs between PCR and PoC antigen tests. Thus, analysing the effect of this delay on the efficacy of surveillance measures may provide valuable insight regarding their usefulness in application. In order to demonstrate possible effects, the different surveillance strategies were simulated for delays of Figure Variation of the outbreak size, defined earlier as A population fully compliant to active surveillance testing is not guaranteed in an application setting. Therefore, the impact of varying levels of compliance with regular preventive testing measures in the clinic population was investigated. Different test frequencies were analysed using the best guess parameters and assuming established baseline surveillance and entry testing. Figure The ongoing COVID-19 pandemic necessitates appropriate public health responses to mitigate consequences for vulnerable populations. Facilities providing long-term treatment for psychiatric patients or care homes for elderly residents provide exemplary settings in which infection surveillance can be conducted at the level of a single institution. Diagnostic tests provide the means to establish surveillance, as they have been essential to detect ongoing outbreaks and prevent further spread of the virus and will continue to be at the center of infection control in the light of emerging virus mutations . With grWe employed an individual-based model tailored to the setting of a typical mental health treatment facility to explore different surveillance strategies intended to suppress COVID-19 outbreaks. We modelled four surveillance strategies: symptom-based baseline surveillance, entry testing, testing once a week or testing twice a week. For each active surveillance strategy, estimates for the relative reduction of outbreak probability compared to the baseline strategy were obtained. We investigated critical determinants of the epidemiological dynamics and found that fast test results, high compliance and high test sensitivity are crucial to maximize efficacy of active surveillance. Investigation of the average number of diagnostic tests conducted and individuals under quarantine per day showed that regular testing is practically feasible if specificity of the diagnostic test is sufficiently high as this implies a low number of false positive test results.A comprehensive sensitivity analysis confirmed the robustness of the obtained results under varying assumptions about a set of uncertain parameters, representing alternative epidemiological parameters as well as alternative structural assumptions. Moreover, the stochastic nature of the simulation model has been controlled for by generating a sufficient amount of simulation runs. Although an appropriate analysis of uncertainty has been conducted, the 1-way sensitivity analysis employed does not yield confidence or credible intervals on the generated estimates. However, the 1-way sensitivity analysis provides easily interpretable outcomes and introduces no additional bias compared to probabilistic sensitivity analyses, which require the specification of poorly known parameter probability distributions .The best-case and worst-case ranges represent extreme case parameter sets and overestimate the underlying parameter uncertainty. While this can help to put results into perspective, the true effect estimates are much more likely to be in the vicinity of the reductions estimated for the best guess parameters. Additionally, some of the parameters with large impact on the model such as the test sensitivity and compliance are not necessarily unknown and should therefore be interpreted apart from truly uncertain epidemiological parameters, which is not considered in the best/worst case analysis.We focused on the suppression rather than mitigation of outbreaks, defined here as 2–5 newly infected individuals over the course of 10 days. This approach differed from previous modelling studies which considered outcomes that focus on late outbreak stages, e.g. the number of cumulative infections –9. The sThe small outbreak setting additionally reduces the impact of the modelled contact structure on the simulation results considerably. Indeed, we could see in our study that the impact of the parameter controlling the extent of heterogeneity in the contact structure was negligible. Therefore, only the variation of individual transmissibility needed to be incorporated into the model, but not necessarily an explicit contact structure as employed in many other studies –9, 31 inDiagnostic tests have been characterized in the model by their sensitivity, specificity and their test-to-result delay without explicitly relating these to a PCR or PoC test. A PoC antigen test will usually imply a short test-to-result delay, while a PCR test should come with the benefit of a higher sensitivity and specificity. The value of these performance measures will vary between manufacturers, virus variants and the quality of the sample, such that the model results are to be interpreted in the light of the assumed test characteristics. While from a mathematical point of view it is legitimate to consider diagnostic tests with low sensitivities, surveillance with only low-sensitivity tests is unreasonable in the context of the case-ascertainment process assumed in the model. In applications, faster low-sensitivity tests can be used to screen for cases as long as results are confirmed with a diagnostic test with adequate sensitivity and specificity. This non-trivial model extension was not considered in our analyses. Diagnostic tests quickly become unsuitable for regular surveillance testing if their specificity is too low, because the resulting amount of false positives is problematic in active surveillance settings, which is well supported by our model results.Another important structural limitation is the assumption of constant sensitivity of diagnostic tests during the course of disease. To account for this, the course of disease could be defined based on a viral load profile across time which is proportional to the infectiousness of an individual as well as to the sensitivity of the diagnostic test . CurrentCOVID-19 surveillance in hospitals with long treatment duration and long-term care facilities provides a unique opportunity to create a safe environment for a vulnerable population. In this context, adequate assessment of the gain of various mitigation strategies is sparse but urgently needed to establish standards for practical implementation of strategies. In order to complement the existing literature, we quantified the effect of various surveillance strategies on the probability of occurring viral outbreaks. We demonstrated that implementing these strategies is practically feasible. We found that improving strategies based on isolating symptomatic individuals by means of testing-based strategies requires fast diagnostic test results, highlighting a possible use of point-of-care tests in this setting. Furthermore, we highlight the importance of a compliant population in order to maximize efficacy of regular testing. Overall, our results suggest that establishing surveillance exceeding symptom-based screening alone can successfully reduce disease burden in hospitals and long-term care facilities.Additional file 1. Summary of epidemiological characteristics for the article.Additional file 2. Additional methods for the article.Additional file 3. Additional results for the article.


Infective endocarditis is a sinister condition with considerable morbidity and mortality. Its relevance in the current era is compounded by the increased use of implanted devices such as replacement valves or cardiac implantable electronic devices. These infections are caused by multiple different bacteria with different virulence, pathogenicity, and antimicrobial resistance. Unlike in native endocarditis, the presence of foreign tissue permits sustenance by inflammatory and thrombotic processes as the artificial surfaces promote inflammatory responses and hypercoagulability. Prevention of these infections has been suggested with the use of homografts in combination with antibiotics. Others have attempted to use “low fouling coats” with little clinical success thus far. The use of antibiotic prophylaxis plays a pivotal part in reducing the incidence of prosthesis-related endocarditis. This remains especially crucial with the increasing use of transcatheter heart valve therapies. The widespread use of cardiac implantable electronic devices such as permanent pacemakers, implantable cardioverter defibrillators, and cardiac resynchronization therapy devices has also heralded a noticeable increase in cases of infectious endocarditis affecting complex equipment which can be difficult to treat. Multimodality strategies are needed with input from surgeons and cardiologists to ensure treatment is both prompt and successful, tailored to the individual needs of the patients. The current era is characterized by remarkable advances in the field of cardiology with noticeable changes in patient demographics and disease manifestations , 2. Thisorganism , 4.The emergence of new cardiac implantable electronic devices (CIEDs) has also heralded a noticeable increase in cases of infectious endocarditis (IE) affecting complex equipment . LikewisAnother aspect to consider is healthcare-associated infection, which is the result of complicated care in patients who have received the next generation of cardiac devices. Despite the burden of healthcare-associated infections in high-income countries being significantly lower than those occurring in low-income countries , there iGiven the constant evolution of infections associated with implants and implantable devices in cardiopathic patients, an evaluation of therapeutic and innovative biomaterials against medical device-associated infections, 2 crucial challenges should be considered: preventive therapy against the most aggressive strains of pathogens and the infection of heart devices including conventional mechanical or biological prosthesis, transcatheter heart valve implantation (THVI), and CIED.Staphylococcus aureus represents the most common pathogen among healthcare-associated organisms accounting for around 30% of cases [Staphylococcus aureus is found in 70% of the examined.Infective endocarditis can occur in patients who require the implantation of a cardiac device during initial hospitalization or after discharge from the hospital. of cases . It is iStaphylococcus aureus is the high aggressiveness of the infection which frequently causes complications such as an increased risk of embolism and stroke. Certainly, persistent bacteremia of the pathogen in the blood with distant colonization supports critical illness, systemic sepsis, and death [Enterococci, on the other hand, are the cause of an additional 10% of bacterial colonization [Concern related to the clinical picture of patients with endocarditis sustained by nd death . Other gnization .Staphylococcus aureus, infections caused by coagulase-negative staphylococci (CoNS), as for example Staphylococcus epidermidis, Staphylococcus lugdunensis, and Staphylococcus capitis, have assumed a particular menace. One of the characteristics that make staphylococci CoNS potentially very harmful is that they are ubiquitous and skin commensal, so they can easily colonize infusion catheters and indwelling devices [With the increase in infectious endocarditis supported by  devices –16.staphylococci CoNS also concerns the infectious processes that develop in the materials that make up the valve bioprostheses and CIEDs. In implanted biomaterials, bacterial colonization of pathogens such Staphylococci CoNS can reach up to 10%, thus, characterizing device infections (bioprosthesis and CIED) for two reasons [Lugdunensis strain of Staphylococcus, endowed with a particular aggressiveness towards biological tissues and biomaterials [The concern related to early endocarditis caused by  reasons , 16. The reasons . The secaterials .haemophilus, aggregatibacter, cardiobacterium, Eikenella corrodens, and kingella) are responsible for a low percentage of infections (3% of cases). The peculiarity that makes these pathogens insidious is the slow growth and the frequent colonization in the oropharynx, and they can adhere to the cardiac devices of immunosuppressed patients [There are other opportunistic pathogens, zoonotic bacteria, and fungi that can lead to the development of particularly insidious infections. Bacteria included in the HACEK group (patients .Acinetobacter spp and Pseudomonas aeruginosa), Legionella spp, Mycoplasma spp, and Tropheryma whippelii [Candida or Aspergillus, which although infrequent, are however lethal and aggressive. They occur mainly in immunosuppressed patients or after cardiac surgery procedures, especially in patients who have received prosthetic valves or devices for the treatment of arrhythmias [Unusual pathogens causing IEs include Gram-negative bacteria  to support the observational studies –44. The p < 0.0001) [The 2015 report from the Society of Thoracic Surgeons [  0.0001) –53 . This pyrolytic carbon prosthesis consisted of a silver-coated sewing ring and was enthusiastically implanted for three years starting in 1997 because it provided an antibacterial coating. The results of the follow-up mitigated the initial enthusiasm for the high rate of thrombosis and perivalvular leak manifested in the Silzone prosthesis recipients , 63. TheSeveral studies have focused on the limitation of antibiotic prophylaxis on the incidence of IE in the presence of devices. Opinions differ between public health agencies in various countries.In France, restrictions on the use of oral therapy with antibiotics have been in place since the early 2000s where the administration of drugs is limited to high-risk cases. An analysis involving the different French regions did not show substantial changes in the incidence of heart infections although restrictions on taking oral antibiotic prophylaxis were not modified. The data reported from this study confirmed no significant change in the incidence of oral streptococcal infection , 65.In 2007, the position of the American College of Cardiology/America Heart Association (ACC/AHA)  was to lThe data reported by 2 nationwide epidemiological studies, one from the United States and the other from the United Kingdom, are in clear disagreement with the French experience. They provide food for thought. The study by Pant et al.  based onIn the 21st century, new platforms for the treatment of structural heart diseases have emerged, and heart infections have therefore continued to evolve, reaching a rate of increase of >25% in cases needing further treatment.The new transcatheter heart valve (THV) prostheses that use a minimally invasive procedure either trans-thoracic or percutaneous approach have radically changed the treatment of structural heart valve disease. The transcatheter heart valve therapy (THVT) in the last 10 years, after use in the first instance for more fragile patients with multiple comorbidities and high surgical risk, has been successfully extended to intermediate and low-risk patients. It is important to note that, due to the characteristics of fragility and comorbidity in which there are many patients, the increased risk of bacteremia and infective endocarditis is not negligible .The devices available on the market are the balloon, self, and mechanical expandable systems. The first two commercial transcatheter heart valve platforms that were approved for use in high or extreme risk surgical patients were the Edwards Lifesciences intra-annular balloon-expandable transcatheter heart valve platform –77 and tThe next generation of balloon-expandable valve is the SAPIEN 3 system (Edwards Lifesciences). The SAPIEN 3 THV (Edwards Lifesciences) is a balloon-expandable, transcatheter aortic heart valve replacement device system that consists of a cobalt-chromium alloy frame and bovine pericardium leaflets  Figures. The altRecently, 2 other self-expandable devices have been evaluated in randomized controlled trials: the Portico  Self-expanding intra-annular Re-sheathable Transcatheter Aortic Valve System  and the The Portico valve is composed of three intra-annular, bovine pericardial tissue valve leaflets mounted in a radiopaque, nonflared, self-expanding nitinol frame with a porcine pericardial valve sealing cuff  Figure . The ACUA very low rate of infection was described in the pilot PARTNER randomized trial –77.enterococci strains in 24.6% and S. aureus in 23.3%.The landmark study from Reguiero et al.  is the fSixteen centers (13608 patients) declined to participate with individual data contributing to a significant bias in the understanding of results. Another potential bias could arise by the recruitment of centres from very different health care systems across the world. The difference in clinical approaches, treatment protocols, postoperative management, and home-care assistance play an important role in the development of postoperative infections. The only parameter directly related to the procedure predicting endocarditis risk was aortic regurgitation, but the lack of intermediate data between TAVR and rehospitalisation prevents a full understanding of the pathological evolution. Worsening of NYHA class, rehospitalisation for heart failure, or dialysis would provide important information, especially for primary-care physicians to refer the patient and avoid triggers for infection. Endocarditis patients were younger, reflecting the current expansion to lower-risk candidates of TAVR. The in-hospital mortality rate was 36%, and surgery was performed only in 14.8% of the patients during the infective endocarditis episode. In survivors, overall mortality at 2 years was as high as 67%. These data outnumber the ones on surgical mortality for prosthetic valve endocarditis after surgical aortic valve replacement  and on mInterestingly, this study arrives timely after the one from Hansson et al.  reportinStaphylococcus CoNS 25%; Staphylococcus aureus 21%) or enterococci (21%). The colonization of the device by pathogens was indifferently localized on the stent frame, the leaflets, or both components. It should be noted that antibiotic prophylaxis was used in 59% of the infected and that although the self-expanding CoreValve system  was an independent risk factor for IE , this deserves further evaluation for validation.A multicenter study  reportedStaphylococcus aureus in 38% of cases, enterococci in 31%, Staphylococcus CoNS in 9%, and streptococci in 9.1% of cases.Another study  reportedNone of the materials assembled in the devices described –82 seemsCardiac device infections (CDI) have increased in proportion, distinguishing healthcare in the 21st century from the 20th –88. The It is important to underline the disproportion that exists between the number of CDI reported in the United States  compared to the corresponding increase in the rate of implanted devices, thus, recording a large tendency for materials to develop infection , 86–88. Endocarditis occurring from the CIED usually involves the generator pocket and subsequently progresses to the generator leads. From these, if not promptly counteracted, it can extend to the valvular and nonvalvular endocardial surfaces. Commonly, the initial inflammatory process is characterized by cellulitis or erythema and is limited to the pocket containing the generator. Its evolution as a widespread infection sees the involvement of the entire device whereby eradication is very difficult. The infected material and evident erosion of the skin overlying the pocket highlight a considerable risk of haematogenous spread of the infection.Staphylococci belonging to the CoNS strain are the leading pathogens responsible for infection between 60% and 80%. Enterococcus faecalis is the most common causative pathogen in patients with digestive system cancer for whom CIED implantation is required [required –89. In trequired , 22.To avoid the onset of endocarditis of CIED, the use of antibiotic therapy as prophylaxis is recommended by evidence reported in both RCTs and observational studies. Prolonged use of antibiotic administration may be required in conjunction with negative serial blood cultures for 72 hours prior to reimplantation if the use of a new device is required , 91.Treatment of CIED-related right-sided endocarditis is an emerging field , 92, 93,The severity of the infection guides the choice of procedure. Involvement limited to leads may involve simple extraction of the infected material which can be performed percutaneously , 95. HowConsidering the worrying epidemiology of the problem and the causal etiology, two principles emerge for an adequate management strategy of CIED-related tricuspid valve endocarditis. First, the creation of a team dedicated to endocarditis made up of surgeons and cardiologists to avoid delays in diagnosis. Second, treatment with a stricter antibiotic prophylaxis policy is aimed at protecting high-risk patients and multidrug-resistant organisms .Another growing subgroup of patients at risk for tricuspid valve endocarditis are individuals with end-stage renal disease for whom vascular access and CIED are required. For these patients, the risk reduction strategy involves performing arteriovenous fistulas on the contralateral upper limb to allow for the placement of an implantable cardiac electronic device so as to avoid the introduction of the central venous catheter. The increasing use of miniaturized CIEDs and even leadless pacemakers/implants is an important prospect for patients with rapidly progressing chronic kidney disease .Importantly, the studies by Polewczyk et al. , 99 streIn this direction, a benefit derives from treatment with anticoagulant and antiplatelet drugs. Therefore, the efficacy of chronic anticoagulant therapy and antiplatelet treatment should lead us to consider this medical treatment as indispensable choice for the prevention of CIED infection.Infective endocarditis continues to be a disease with significant morbidity and mortality. With the increasing use of implantable valves or devices, there has been a shift in the treatment and prevention strategies of these infections. Treatment often requires input from the multidisciplinary team due to the complex nature of the presenting patients. Antibiotic prophylaxis may have a role in reducing the incidence of these infections but further trials are needed to substantiate findings from previous studies.


While many European Union/European Economic Area (EU/EEA) countries recently expanded human papillomavirus (HPV) vaccination to boys, HPV vaccine supply is currently limited for girls in low- and middle-income countries (LMIC) that are severely affected by HPV.Globally, about 50% of countries have introduced HPV vaccination. Some LMIC with high burden of cervical cancer have not yet introduced HPV vaccination, or are reaching suboptimal vaccination coverage. While WHO issued a call for cervical cancer elimination in 2018, a global shortage of HPV vaccines is currently predicted to last at least until 2024.We reviewed national policies of EU/EEA countries and recommendations of the World Health Organization (WHO) Strategic Advisory Group of Experts on immunisation to discuss current challenges and dose-sparing options. Several EU/EEA countries have extended HPV vaccination to boys and the European Cancer Organisation has issued a resolution for elimination of all HPV-associated cancers in both sexes. The European Centre for Disease Prevention and Control concluded in its 2020 guidance that cost-effectiveness of extending routine vaccination to boys depends on several context-specific factors. The extension of HPV vaccination to boys in EU/EEA countries may affect global availability of vaccines. Temporary dose-sparing options could be considered during the COVID-19 post-pandemic period. Human papillomavirus (HPV) infection is the most frequent sexually transmitted disease and the second most common cause of cancer attributable to an infectious agent globally . CervicaIn view of the large burden of cervical cancer attributable to HPV, immunisation strategies against HPV infection have initially focused exclusively on girls.From the growing body of evidence, including clinical trials, field trials, large cohort studies and ecological studies on the impact of HPV vaccination, HPV vaccines have proven to be generally safe and effective against persistent HPV infection, anogenital warts, and pre-cancerous lesions, in particular when administered to HPV naive subjects. There is also evidence of substantial indirect (herd) protection when vaccine coverage is above 50% ,4.We review and discuss the implications of the expansion of HPV vaccination to boys in the European Union/European Economic Area (EU/EEA) in light of the current cervical cancer elimination goals and of the global shortage of HPV vaccines, which is mainly affecting girls in low- and middle-income countries (LMIC).Globally, by 2020, about half of all countries have introduced HPV vaccination, covering about one third of the eligible population of girls. Low- and middle-income countries have the lowest rates of introduction of HPV vaccination and some are struggling with its introduction while experiencing a high burden of cervical cancer and HPV-associated illness . A recenA call for elimination of cervical cancer was issued by the World Health Organization (WHO) in May 2018, followed by the American Cancer Society in June 2018 ,8. In Seextend the benefits of vaccines to everyone, everywhere” and identifies vaccination ‘coverage and equity’ as one of its seven strategic priorities [The WHO considers vaccination fundamental for equity in healthcare and beyond. It is one of the key elements of primary healthcare and universal healthcare coverage. The proposed Immunisation Agenda 2030 aims to “iorities . All vacIn 2008, the European Centre for Disease Prevention and Control (ECDC) produced its first guidance on HPV vaccination in EU/EEA countries following the introduction of the first two vaccines against human papillomavirus . The guiSupplementary Table) and concluded that cost-effectiveness of extending HPV vaccination to boys depended on several factors, many of which are context-specific. The cost of the HPV vaccine was the main driver of the incremental cost-effectiveness ratio (ICER) when comparing a scenario of universal vaccination with a baseline scenario of vaccination of girls only. Notably, the extension of HPV vaccination to boys appeared more cost-effective compared with increasing vaccine uptake among girls in cases where vaccination coverage among girls is persistently lower than 75–80% [As part of the guidance, a systematic review of studies looking at cost-effectiveness of extending routine HPV vaccination to boys was performed  and the United Kingdom (UK) have extended, or have decided to extend in the coming years, HPV vaccination to boys, while other countries are discussing the opportunity to extend it soon , Table 2The WHO has highlighted that the current global HPV vaccination shortage, foreseen to last at least until 2024, might delay the introduction of HPV vaccination in the countries most in need . In partBetween 84% and 90% of all cervical cancers occur in LMIC and implementation of mass screening remains a major challenge in several of these countries. Recent projections showed that an estimated 11 million women from LMIC will be diagnosed with cervical cancer in the next 10–20 years. Many of these cervical cancers are diagnosed late and thus have poor prognosis . In thesAdditionally, it should be noted that the average individual health benefit obtained from a dose of vaccine administered to a boy in the EU/EEA is substantially lower than the average individual health benefit obtained from a dose of HPV vaccine given to a girl in LMIC where cervical cancer screening is not implemented or well-established. The WHO’s Strategic Advisory Group of Experts (SAGE) on immunisation recently recommended a temporary pause in the implementation of HPV vaccination of boys in those countries that are considering doing so . It was In light of the limited evidence available, the use of a single dose of an HPV vaccine is currently not recommended. However, a substantial amount of research is ongoing. Non-randomised data from post-hoc analyses of two randomised controlled trials (RCTs) from Costa Rica and India (the latter now converted into a cohort study), using bivalent and 4-valent recombinant HPV vaccines respectively, showed that immunogenicity was still observed years after a single dose of HPV vaccination, although inferior to that observed after two or three doses ,26. ReceAlternative dose-sparing options are also being considered. Vaccination schedules could be modified in order to spare doses and gain time during the current vaccine shortage. Different options were proposed at the SAGE meeting in October 2019, however, it was concluded that the feasibility of the suggested alternative schedules would need to be carefully assessed in each different context . One cosOther gradual approaches may also be contemplated. The Immunisation Committee from the Province of Quebec in Canada recently recommended an off-label mixed schedule using the 9-valent HPV vaccine as a first dose, and the bivalent HPV vaccine as a second dose, until evidence of effectiveness of a single dose of HPV vaccine becomes available ,32. The The COVID-19 pandemic has affected national routine immunisations and may influence the future priorities of vaccination programmes in many countries. A modelling study estimated that, because of the impact of the pandemic on HPV vaccine uptake, over 130,000 cases of genital warts and between 2,882 and 6,487 cases of cervical cancer will not be avoided in the US over the next 100 years, with over 60% of them occurring in the next 50 years .Too many girls living in LMIC with a high burden of cervical cancer are not vaccinated against HPV, hence the global call for action for cervical cancer elimination. In high-income countries, including several EU/EEA countries, the priority has shifted towards the prevention of all HPV-associated illness and the equity of access to HPV vaccination for all genders thanks to successful vaccination and screening strategies against cervical cancer. In view of the current global HPV vaccines shortage which could be affected by the current COVID-19 pandemic in different ways, and given the growing global demand for HPV vaccines, there are different aspects to consider including equity of benefit, equity of access globally, current and future vaccine supply, national and international health needs and priorities, costs and political imperatives. The SAGE issued clear and sensible temporary recommendations, however, countries that have already extended HPV vaccination to boys, or have already decided to extend it, may face important challenges to provisionally reverting or modifying their decision after long debates on the opportunity to do so.The dose-sparing options suggested by SAGE represent possible temporary solutions, in particular the extension of the time interval between the first and the second dose of the HPV vaccine. However, the communication and implementation of such temporary decisions may be difficult and might affect HPV vaccination confidence and uptake of the full two-dose schedule. The potential impact of the COVID-19 pandemic on supply and uptake of other vaccines suggests postponing any further change of the current vaccination schedules to the post-pandemic phase.


Ehlers Danlos syndromes (EDS) are a group of genetic disorders, characterized by skin hyperelasticity, joint hyperlaxity and tissue weakness. Vascular EDS is rare and is differs from other types of EDS by an inconsistent acrogenic morphotype and the occurrence of severe digestive and vascular complications, which can be lifethreatening.We report the case of a 27-year-old man with a type IV vascular Ehlers-Danlos syndrome revealed by a colonic perforation after appendectomy for peritonitis secondary to appendicitis. The etiology of the perforation remained a challenge till a genetic research was carried out for COL3A1 gene mutation, which was positive in favor of vascular Ehlers Danlos disease. Then, a totalization of the colectomy with ileorectal anastomosis was performed.Vascular Ehlers Danlos syndrome (VEDS) is due to qualitative and quantitative abnormalities in the synthesis of type III collagen, which is a major constituent of the vessel wall, skin, joint capsules, uterus and gastrointestinal tract, particularly the colon. Colonic perforation, particularly sigmoidal perforation, is the most frequent complication in SEDV and most often precedes the molecular diagnosis. Colonic perforations are uncommon. The Hartmann procedure is a well-established surgical treatment modality, especially for emergency surgery. Given the iterative risk of colonic perforation and anastomotic leakage, preventive treatment by total colectomy with ileo-rectal anastomosis or definitive ileostomy is recommended by several authors.SEDV is a rare pathology with a difficult diagnosis. However, it should be keeped in mind when there is any spontaneous colonic perforation in the young people. •Ehlers danlos syndromes are a group of genetic disorders of the connective tissue.•Life expectancy is reduced due to spontaneous vascular rupture or colonic perforation.•Colonic perforations are uncommon. They occur in the context of diverticulitis in adults.•The diagnosis is difficult because of the rarity of the pathology and the inaccessibility of genetic tests.•The surgical management of colonic perforations in ehlers danlos syndromes is not codified. Its prevalence is estimated at 1 per 150 000 .Life expectancy is reduced (mean age 45–50 years), due to spontaneous vascular rupture or colonic perforation . The firWe report the case of a 27 year old man with vascular Ehlers Danlos syndrome revealed by sigmoid perforation for whom a total colectomy was performed with deferred ileorectal anastomosis as a preventive measure. The aim of this case is to discuss the place of preventive total colectomy in Ehlers Danlos disease according to literature review. This case have been reported in line with scare guideline 2020 .1.1A 27-year-old man with history of appendectomy and peritonitis due to sigmoid perforation. A segmental sigmoidal resection with Hartmann colostomy were performed. The specimen analysis did not reveal any inflammatory sign of bowel disease.Three months later, the patient presented an occlusive syndrome complicated with stoma and the small bowel necrosis. A 43-cm small bowel resection with end to end anastomosis and 10 cm colonic resection associated with a left iliac fossa colostomy rebuilt were performed. The specimen analysis showed moderate congestive interstitial colitis with the presence of numerous eosinophilic polynuclear cells exceeding 40 PNE/field, which could be in favor of eosinophilic colitis, without granulomatous lesions or other signs of IBD. Examination of the bowel resection showed a regular moderately inflammatory mucosa without cryptic abnormalities with some giant cells and rare granulomas in the muscular.-Thin, loose skin,-Hypoplasia of the ear lobule [A].-Madonna face appearance: pinched nose, horizontal lips, prominent cheekbones, and sunken and dark circled eyes [B].-Acrogeria of the hands [C].On third hospitalization, physical examination showed :-Thin, l-Atrophic aspect of the median laparotomy scar-Postoperative eventration of the linea alba with a ring sac 10 cm in diameter.Abdominal examination showed:The remain of physical examination was normal.The etiology of the perforation remained a challenge for this patient and after morphotype analysis, a genetic research was carried out for COL3A1 gene mutation, which was positive in favor of vascular Ehlers Danlos disease. Then, a totalization of the colectomy with ileorectal anastomosis was performed , associa2(5), . Onl. Onl8]. By the way, any idiopathic colonic perforation in a young adult, in the absence of colonic pathology, should require a genetic study for SEDV . In 47% In the literature, the surgical management of colonic perforations in SEDV is not codified, the main reasons being the rarity of the disease, the absence of a formal diagnosis at the time of the first colonic perforation, and the need for emergency surgical treatment ,11.The Hartmann procedure is a well-established surgical treatment modality, especially for emergency surgery. Given the iterative risk of colonic perforation and anastomotic leakage, preventive treatment by total colectomy with ileo-rectal anastomosis or definitive ileostomy is recommended by several authors . HoweverA recently published meta-analysis by Speacke et al. describes 109 operations performed in 51 patients with EDS reported in 44 case series and allows to establish a management strategy in EDS by evaluating the risk of intestinal perforation recidivisme in the therapeutic management. Indeed, the rate of recidivisme is significantly higher after colo-colic anastomosis, compared to ileo-rectal anastomosis , survival analysis also increases with total colectomy compared to other operative modes. The author therefore suggests that total colectomy with ileorectal anastomosis or definitive ileostomy should be performed to prevent the subsequent risk of perforation in any patient with confirmed Ehlers Danlos syndrome.This strategy would limit the risk of certain immediate complications , which has a high (66%).For our patient, a total colectomy with ileo-rectal anastomosis was performed.3SEDV is a rare pathology, the diagnosis is difficult because of the ignorance of the pathology and the inaccessibility of genetic tests. However, it should be keeped in mind when there is any spontaneous colonic perforation in the young people.The surgical management of colonic perforations recommends total colectomy with ileo-rectal anastomosis or definitive ileostomy as a preventive measure, justified by the high rate of recurrence and anastomotic fistulas.The study is exempt for ethical approval.None.Khalid Elhattabi: manage the research and design and write the first draft of the manuscript.Hasna Benghait: manage the research and design and write the first draft of the manuscript.Abdelilah Elbakouri: manage the research and design and write the first draft of the manuscript.Mounir Bouali: manage the research and design and write the first draft of the manuscript.Fatimazahra Bensardi: correction of the paper.Abdelaziz Fadil: correction of the paper.This is not the first case and the registration is not required.The Guarantor is the one or more people who accept full responsibility for the work and/or the conduct of the study, had access to the data, and controlled the decision to publish.The authors declare having no conflicts of interest for this article.