This study is aimed to investigate the association of intraosseous (IO) versus intravenous (IV) route during cardiopulmonary resuscitation (CPR) with outcomes after out-of-hospital cardiac arrest (OHCA).I2 statistics. Time to intervention, defined as time interval from call for emergency medical services to establishing vascular access or administering medications, was hypothesized to be a potential outcome moderator and examined in subgroup analysis with meta-regression.We systematically searched PubMed, Embase, Cochrane Library and Web of Science from the database inception through April 2020. Our search strings included designed keywords for two concepts, i.e. vascular access and cardiac arrest. There were no limitations implemented in the search strategy. We selected studies comparing IO versus IV access in neurological or survival outcomes after OHCA. Favourable neurological outcome at hospital discharge was pre-specified as the primary outcome. We pooled the effect estimates in random-effects models and quantified the heterogeneity by the I2, 95%). In subgroup analysis, time to intervention was noted to be positively associated with the pooled OR of achieving the primary outcome . That is, when the studies not accounting for the variable of “time to intervention” in the statistical analysis were pooled together, the meta-analytic results between IO access and favourable outcomes would be biased toward inverse association. No obvious publication bias was detected by the funnel plot.Nine retrospective observational studies involving 111,746 adult OHCA patients were included. Most studies were rated as high quality according to Newcastle-Ottawa Scale. The pooled results demonstrated no significant association between types of vascular access and the primary outcome (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.27–1.33; The meta-analysis revealed no significant association between types of vascular access and neurological outcomes at hospital discharge among OHCA patients. Time to intervention was identified to be an important outcome moderator in this meta-analysis of observation studies. These results call for the need for future clinical trials to investigate the unbiased effect of IO use on OHCA CPR.The online version contains supplementary material available at 10.1186/s13049-021-00858-6. In the United States, there are more than 300,000 out-of-hospital cardiac arrests (OHCA) every year, and the survival rate at hospital discharge is around 10% , 3 suggeEwy et al.  indicateUpdated guidelines by American Heart Association consider intraosseous (IO) access an acceptable vascular access , while EThis systematic review and meta-analysis were performed in accordance with the guidelines of PRISMA   and MOOSTwo investigators (YLH and MCW) independently searched the databases, including PubMed, Embase, Cochrane Library and Web of Science, from the database inception through April 2020. Our search strings included designed keywords for two concepts, i.e. vascular access and cardiac arrest  independently scanned the titles and abstracts of all retrieved articles to determine whether the articles were pertinent to this review. We used the following prespecified inclusion criteria: (a) population included patients with OHCA, (b) comparison between IO and IV access for medications administration during CPR, (c) outcomes included survival or neurological results, and (d) study designs included randomized controlled trials, quasi-randomized controlled trials, and observational studies (cohort studies and case-control studies). Case series, reviews, editorials, comments and studies on non-human subjects were not included. We excluded studies that included trauma patients. Full-text articles were retrieved if either of the investigators considered the abstract potentially suitable. After retrieving the full reports of potentially relevant studies, two investigators (JW and JE) independently assessed each study’s eligibility on the basis of the inclusion criteria. Differences of opinion regarding study eligibility were settled by consultation with another investigators (TCL and EPCH).In this review, favorable neurological outcome at hospital discharge was pre-specified as the primary outcome. Short-term survival and survival at hospital discharge were the secondary outcomes. Since the definitions for short-term survival were various, we abstracted those outcome data for which the timing was closest to hospital admission.Two investigators (CHH and EHC) independently extracted qualitative and quantitative data according to a predesigned spreadsheet (Excel [Microsoft]) that was pilot-tested beforehand; a third investigator (WJC) adjudicated discordant assessments. Data were extracted for author information, publication year, study design, study setting, patient number, patient characteristics, selection method for intervention and comparator, definitions of outcomes, unadjusted/adjusted effect estimates and their corresponding 95% confidence intervals (CIs). The patient number was extracted on an intention-to-treat basis. If more than one adjusted effect estimates were reported in a single study, we selected the representative effect estimate according to the following hierarchy of priority: (a) effect estimates derived from multivariable statistical model, (b) effect estimates specifically adjusted for time to intervention, (c) comparison between patients categorized by first attempted vascular access, (d) effect estimates comparing IO versus IV access for active medications, and (e) effect estimates calculated with the largest patient number. If an adjusted effect estimate was not available, an unadjusted one was recorded or calculated manually for analysis. If included studies provided additional effect estimates of IO versus IV access for patients with shockable rhythms, these estimates would also be extracted.Without blinding to study authors or journals, two investigators (CHH and EHC) independently assessed the study quality using the Newcastle-Ottawa Scale, which rates the quality of observational studies in a standardized and structured format . ConflicI2 statistics, with I2 > 50% deemed as the presence of significant heterogeneity [Odds ratio (OR) was selected as the primary effect estimate for data synthesis. Since the proportion of patients recovering favorable neurological outcome in OHCA was relatively small, all other measures of effect estimates, such as risk ratio (RR), were assumed to approximate the OR and pooled in meta-analyses if OR could not be obtained. Weighted means of the ORs, with their associated 95% CIs, were calculated in random-effects models (DerSimonian-Laird method ) with thogeneity , 16.To examine heterogeneity, we performed subgroup analysis based on predefined moderator variables, including study year and location, selection method for intervention and comparator , EMS response time , time to intervention  adjusted in analysis, and type of effect estimates pooled in meta-analysis (adjusted versus unadjusted). In the subgroup analysis, the effect sizes stratified on the same moderator were re-estimated and compared in mixed-effects meta-regression analysis to examine the impact of each moderator on pooled ORs. Additional effect estimates for patients with shockable rhythms were also synthesized in the subgroup analysis. Finally, the presence of publication bias was examined using funnel plots.metafor package and rma function were used to perform meta-analysis and meta-regression in the R 3.6.3 software . In the statistical testing, a 2-sided p < 0.05 was considered statistically significant.The After a systematic literature search, we included nine studies –25 involThe patient demographic data were similar across included studies, except the study by Daya et al. , which eMost studies used multivariable analysis to adjust the confounding effects of multiple variables, except two studies , 21. DesMost studies , 23–25 uMost studies achieved similarly high Newcastle-Ottawa Scale scores . Subsequently, after adding the study by Zhang et al. [I2, 71%) but also worse neurological outcome at hospital discharge , though the heterogeneity of this expanded meta-analysis increased substantially. Interestingly, it was the latest Zhang et al. study [Two previous meta-analyses , 27 indig et al.  to the pg et al. , Granfell. study  that prel. study  study, aCompared to these previous studies , 27, ourDespite that most of the included studies used multiple statistical methods to account for confounding factors and were rated as high quality on Newcastle-Ottawa Scale, the inherent limitations of the retrospective observational study design may still limit the interpretation of current meta-analytic results, indicating the need for a high-quality clinical trial.First, the selection method in vascular access, i.e. first attempted versus actual access, may lead to confounding by indication. Successful IV cannulation can be challenging during CPR because of compromised peripheral vasculature. Depending on the EMS policy, IO access may be used as the last resort for medications administration , 23, 24 Second, not accounting for time to intervention may introduce resuscitation time bias , i.e. loBecause of the above-mentioned risks of bias, the meta-analytic results should be applied cautiously in clinical practice. Previous studies , 6 demonThere are some limitations in our study. First, we did not have enough information to include the site of IO insertion in the subgroup analysis. Humeral IO access of adrenaline administration has been shown to reach higher maximum serum concentration in a shorter time, compared with tibial IO access, thereby leading to higher chances of survival . It was The meta-analysis revealed no significant association between types of vascular access and neurological or survival outcomes at hospital discharge among OHCA patients. Time to intervention was identified to be an important outcome moderator in this meta-analysis of observational studies. These results call for the need for future clinical trials to investigate the unbiased effect of IO use on OHCA CPR.Additional file 1. Search strategy for each database.Additional file 2. Newcastle-Ottawa quality assessment scale for cohort studies.Additional file 3. Funnel plot for favorable neurological outcome at hospital discharge, according to mixed-effects meta-regression model.


The management of critical-size bone defects is still demanding. Recently, autologous platelet concentrates in combination with bone substitute have been applied and reported in a few studies. Our aim is to report the healing of a critical-size alveolar bone defect treated with a new bone regeneration technique by means of L-PRF and L-PRF blocks. A 45-year-old woman presented a large cystic lesion; the extraction of three teeth, a cyst removal procedure, and bone regeneration procedures with L-PRF and L-PRF blocks were planned. The L-PRF block was prepared by mixing a bone substitute with a piece of L-PRF membrane and liquid fibrinogen. Additionally, after bone healing an implant-based rehabilitation was optimally performed. On the basis of the positive results, in terms of bone healing and tissue regeneration in a large bone defect, the application of L-PRF and L-PRF blocks, in agreement with the scarce literature, is suggested as a feasible procedure in selected cases. Tooth loss is known to be related to a bone resorption process that can significantly affect alveolar bone volume. Moreover, if in the presence of a large alveolar bone cyst, the cyst enucleation combined with treatment tooth extraction may end with critical-size defects whose healing may be incomplete due to the size of the defect and the loss of periosteum or bone walls ,2.To prevent the development of severe bone resorption and provide an adequate bone height and width for successive implant rehabilitation, numerous surgical techniques have been proposed, such as alveolar ridge preservation (ARP) or guided bone regeneration procedures (GBR) .Recently, autologous platelet concentrates (APC) have been applied to provide more predictable results in several oral surgical procedures due to their ability to enhance soft and hard tissue regeneration, positively influencing wound healing ,5,6,7.Leukocyte- and platelet-rich fibrin (L-PRF), a strong fibrin matrix produced by the centrifugation of autologous blood, contains cytokines and growth factors such as platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor beta (TGF-b), and shows several healing properties such as angiogenesis, wound protection, and immune control ,6. Recently, the use of a fluid form of PRF has been proposed in order to bond particulate bone substitute, imbibe it with PRF growth factors, and make it more adhesive and stable . The resThe aim of this report was to evaluate the healing of a critical-size alveolar bone defect treated with a new bone regeneration technique by means of L-PRF, as a membrane, and L-PRF block, in order to maintain the bone volume after the extraction of three dental elements and the removal of a large cystic lesion.A non-smoker 45-year-old woman complained of right-side facial pain and swelling, which had begun some days before the first clinical examination.The clinical examination revealed abnormal mobility of teeth #14–16 and pain response to percussion testing. There was no significant systemic complaint. The family history was unremarkable.The dental X-ray showed the presence of a large cystic lesion related to teeth #14–16, which previously had been endodontically treated a. Thus, The final diagnosis was odontogenic cyst and teeth #14–16 with a hopeless prognosis.Based on the findings, teeth extraction, cyst removal, and GBR procedures combined with L-PRF and L-PRF block were planned.Before the beginning of the surgical procedures, L-PRF and PRF block were prepared according to the techniques described by Dohan et al. 2009)  and Cort  and CorIn the red cap tubes, three layers were formed after centrifugation: a base of red blood cells at the bottom; acellular plasma on the top (supernatant); and, finally, a clot of PRF between them. The L-PRF clots were then withdrawn by sterile tweezers and isolated from the red blood cells (RBCs), which, as platelet-poor plasma (PPP), were discarded. To obtain L-PRF membrane, the clots were moved on the grill of the Xpression Box  and pressed for about 5 min. The exudate was collected and kept for next steps. The PRF-block was then prepared. Two L-PRF membranes were cut into small pieces and mixed to 0.5 g of OSP-OX31 osteOXenon Mix Granules  (50:50 ratio); the PLyF and compression exudate were then added to the system, stirred gently for about 10 s, and shaped to obtain a homogeneous complex in the desired form. The activated platelets of the chopped membranes let fibrinogen polymerize into fibrin within few minutes, entrapping the biomaterial into a fibrin network containing platelets and leucocytes.The surgical protocol included (1) chlorhexidine 0.2% mouthwash 30 mL swished up to 60 s; (2) local anesthesia, achieved using 3% mepivacaine hydrochloride without adrenaline; (3) the elevation of a full-thickness mucoperiosteal flap; (4) tooth luxation and avulsion, gently performed with elevators and forceps; (5) the removal of the cyst and debridement of the post-extraction socket with miller surgical curette and irrigation a,b; (6) Histological examination confirmed the odontogenic nature of the cyst . In the following weeks, the patient was under strict oral hygiene measures and on regular recall. Tissue healing was uneventfully; there was no infection or swelling after the surgery and patient did not complain particularly about pain or discomfort.After 10 days, once the sutures were removed, the L-PRF membranes were partially reabsorbed.Six months postoperatively, the bone tissue healing was observed with dental X-ray a,b.The second stage surgery was then performed; before implant placement, using a trephine bur, an alveolar bone sample was obtained from the #15 implant site c. Three Three months after the implant placement, an impression was made; implants were loaded with screw-retained temporary fixed partial restorations. Definitive restoration was placed after 2 months a. The reThe purpose of this report was to describe the healing of a wide alveolar defect with the application of L-PRF in its pure form and as an L-PRF block. Different GBR and ARP techniques have been proposed to prevent bone resorption. Among the graft materials currently used in oral procedures, autologous bone blocks are described as the gold standard. However, the need for a second oral surgical site, especially if outside the oral cavity, is related to a higher patient morbidity and discomfort.The application of several bone substitutes in dentistry has been proposed, with heterogeneous results. The recent findings rely on the advantages of APC to enhance the properties of the bone substitute ,6.L-PRF is a second-generation platelet concentrate; its strong architecture composed of micropores and thin fibers serves as a scaffold for osteogenesis cell migration, differentiation, and neovascularization, maintaining the slow release of growth factors up to a period of 7–14 days ,12. MoreTo enhance the new bone formation, biocompatible bone graft material was processed with L-PRF membranes and fixed with liquid fibrinogen to obtain the L-PRF block. The L-PRF acted in the L-PRF block as a biological connector among the graft particles, creating a matrix with suitable manipulative qualities that was rich in bioactive molecules and growth factors ,9,11,14.Few authors have reported cases of PRF block in human oral surgeries; only 26 interventions in 15 cases have been reported ,15,16. TChenchev et al. evaluated the possibility of the augmentation of the alveolar ridge in the frontal region of the upper jaw in a 18-year old male. The authors applied a combination of bone graft materials, injectable platelet-rich-fibrin (i-PRF), and advanced platelet-rich fibrin (A-PRF). The augmentation procedure was successful and the dental implant was placed .In a single-cohort observational study, Cortellini et al. performed 15 bone augmentation procedures on 10 patients. All the patients (mean age 50.7 years) were affected by horizontal bone defect; the surgical procedures provide the application of L-PRF block , collagen membrane, and L-PRF membranes. Significant horizontal ridge augmentation was obtained with the L-PRF block; which allowed implant placement in all cases .Andrade et al. published a pilot clinical study on four patients; they applied a “dentin block” (a mixture of particulate autologous dentin with chopped L-PRF membranes and liquid fibrinogen) in ten extraction sockets. The “dentin block” was able to promote new bone formation, without host tissue reactions, and a favorable dentin resorption/bone formation rate. All the patients demonstrated an adequate amount and quality of bone for implant placement .To our knowledge, our case report is the first case regarding the application of L-PRF and L-PRF block for the management of large cystic removal and extraction of three teeth.The abovementioned beneficial properties of L-PRF played a key role in remineralization, which was already significant six months after the application.Even if there is no one standard definition of critical-sized defects, alveolar bone defects measuring 2–3 cm in diameter usually heal in about 12 months [In our case, the bone healing was achieved in about six months; moreover, our histological analysis showed that the L-PRF block was able to produce mature alveolar bone tissue. Indeed, the regenerated bone structure allowed the subsequent implant prosthetic rehabilitation.Despite all the limitations of reporting a case, the positive outcomes in terms of bone healing and tissue regeneration reinforced the effective role of L-PRF in oral surgical procedures.The present case report shows that the addition of L-PRF and L-PRF blocks may be successful for bone regeneration procedures also in critical-size defects, supporting the data found in the literature regarding the advantages of APC and especially of L-PRF. Still, further research and randomized controlled trials are necessary to confirm the results presented.


Background: The optimal strategy for patients with coexisting atrial fibrillation (AF) and heart failure (HF) was not settled. Our purpose was to conduct a systematic review and meta-analysis of randomized controlled trials to evaluate the effect of catheter ablation compared with medical therapy for AF on mortality, HF hospitalization, left ventricular (LV) function, and quality of life among patients with HF and AF.Materials and Methods: We searched Pubmed , EMBASE , the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov for randomized controlled trials with a comparison of catheter ablation for AF with medical therapy among patients with coexisting AF and HF. Risk ratio (RR) or mean difference (MD) with 95% confidence interval (CI) was used as a measure of the effect of catheter ablation versus medical therapy on endpoints. Our final analysis included 6 randomized control trials with 775 patients.Results: Pooled results from the random-effects model showed that compared with medical therapy for AF, catheter ablation was associated with reduced all-cause mortality  and HF hospitalization , as well as increased LV ejection fraction (LVEF), distance walked in six minutes, and improvements in quality of life.Conclusions: This updated meta-analysis showed that compared to medical therapy, catheter ablation for AF was associated with significant benefits in several key clinical and biomarker endpoints, including reductions in all-cause mortality and HF hospitalization. Previous study showed that rhythm control with antiarrhythmic drugs does not reduce the rate of death among patients with coexisting HF and AF when compared to a rate-control strategy Recently, a large randomized controlled trial showed that catheter ablation of AF, compared with medical treatment, significantly lowered the rate of mortality in patients with coexisting HF and AF This study was performed in accordance with recommendations from the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) statement “ablation or catheter” and “atrial fibrillation” and “heart failure”. We restricted our search to human and clinical trials. There were no language restrictions. We also reviewed the Introduction and Discussion sections of retrieved trials and relevant review articles to identify additional trials. Two investigators (KLP and ML) independently conducted the literature search, screening of abstracts and selection of included trials.We searched Pubmed , EMBASE , the Cochrane Central Register of Controlled Trials (CENTRAL), and the clinical trial registry maintained at ClinicalTrials.gov with the terms: Criteria for inclusion of a study were as follows: (1) the study design was a randomized controlled trial; (2) the study population was comprised of patients with coexisting AF and HF; (3) the study included a comparison of catheter ablation for AF with medical therapy; (4) reported at least one of following endpoints in active and control groups: all-cause mortality, hospitalization for HF, remained in (or free from) AF, change in LVEF, 6-minute walk distance, and Minnesota Living with Heart Failure Questionnaire (MLHFQ).We abstracted data for baseline characteristics, including age, sex, duration of follow-up, and number of patients in each group. We abstracted data on endpoints from each trial, including number with all-cause mortality, hospitalization for HF, and remained in AF for catheter ablation versus medical therapy. We also abstracted information including increase in LVEF, increase in 6-minute walk distance, and decrease in MLHFQ in active and control group. Two investigators (KLP and ML) independently abstracted data from eligible studies. Any discrepant judgments were resolved by joint discussion that arrived at consensus.2 and I2 statistics. Heterogeneity was considered if the χ2 test was significant (two-sided p < 0.05) or the I2 statistic was > 70 %. The fixed-effect and random-effects estimates of primary endpoint were compared to determine the influence of small-study effects on the results of our meta-analysis, as recommended by Cochrane Handbook for Systematic Reviews of Interventions The primary endpoint was all-cause mortality. Secondary endpoints were hospitalization for HF, remained in AF, change in LVEF, 6-minute walk distance, and MLHFQ. Risk ratio (RR) with 95% confidence interval (CI) was used to assess all-cause mortality, hospitalization for HF, and remained in AF, in the active group compared with control group. Mean difference with 95% CI was used to assess increase in LVEF, increase in 6-minute walk distance, and decrease in MLHFQ (i.e. lower score was considered as the better outcome) in the active group compared with control group. We pooled data from the random-effects model when two or more studies provided sufficient data (e.g. at least one event in either active or control group) for a given outcome. Heterogeneity was assessed by p value of χWe identified eight full articles for detailed assessment, of which one was excluded based on participants in control group were receiving atrioventricular-node ablation with biventricular pacing Overall, 388 patients were randomly assigned to receive catheter ablation for AF and 387 patients were randomly assigned to receive medical therapy for rate and/or rhythm control. Most of the trials enrolled patients with persistent AF, but one large trial enrolled 33% patients with paroxysmal AF Methods of measuring LVEF varied among included trials: two used radionuclide ventriculography 2=0%) . The small study effect was not obvious because results were similar between random-effects and fixed-effect models. Meta-regression was not undertaken because of small number of trials included.For primary endpoint, two studies contained zero events in both ablation and medical groups and were excluded from the pooled analysis. Pooled results from random-effects model showed that catheter ablation for AF compared with medical therapy was associated with reduced all-cause mortality  and there were no heterogeneity among trials  Figure . ResultsPooled results from the random-effects model showed that catheter ablation for AF compared with medical therapy was associated with reduced hospitalization for HF  and patients who remained with AF  , increased 6-minutes walking distance , and improved MLHFQ score  (Figure Ablation related complications are summarized in Although PABA-CHF trial In this meta-analysis comprised of six randomized controlled trials that enrolled over 700 patients with coexisting AF and HF, we found catheter ablation for AF was associated with 48% reduced risk for all-cause mortality, 44% reduced risk for HF-related hospitalization, and 59% reduced risk for AF compared with medical therapy. Additionally, catheter ablation for AF also showed significantly improved LV systolic function, increased the distance walked in six minutes, and improved the quality of life compared with medical therapy.Evidence suggests that HF patients with AF have a worse prognosis than those whose sinus rhythm are maintained, and that the coexisting of AF is a risk factor for death AF and HF are both common heart diseases. Evidence suggests that AF is independently associated with an increased risk of sudden cardiac death This study has several limitations. First, a meta-analysis may be biased when the literature search fails to identify all relevant trials. To minimize these risks, we performed extensive search using multiple literature engines, and trial databases, and included recent review articles. Second, follow-up duration in most of the included trials were less than one year which is less likely to include mortality endpoint. Therefore, the results of primary endpoint, all-cause mortality were largely derived from two clinical trials. Still, both trials showed significantly decreased all-cause mortality rates for catheter ablation compared with medical therapy. Third, success of catheter ablation for AF relies largely on experienced operators, which should be considered when trying to generalize results from clinical trials to real-world practice.This updated meta-analysis showed that catheter ablation for AF compared with medical therapy was associated with risk reduction of all-cause mortality, hospitalization for HF, and AF, as well as increase of LVEF, exercise capacity, and life quality. In the presence of experienced medical operators, catheter ablation for AF might be considered as first-line therapy in patients with coexisting HF and AF.Supplementary figures and tables.Click here for additional data file.


Biosensors are essential tools which have been traditionally used to monitor environmental pollution and detect the presence of toxic elements and biohazardous bacteria or virus in organic matter and biomolecules for clinical diagnostics. In the last couple of decades, the scientific community has witnessed their widespread application in the fields of military, health care, industrial process control, environmental monitoring, food-quality control, and microbiology. Biosensor technology has greatly evolved from in vitro studies based on the biosensing ability of organic beings to the highly sophisticated world of nanofabrication-enabled miniaturized biosensors. The incorporation of nanotechnology in the vast field of biosensing has led to the development of novel sensors and sensing mechanisms, as well as an increase in the sensitivity and performance of the existing biosensors. Additionally, the nanoscale dimension further assists the development of sensors for rapid and simple detection in vivo as well as the ability to probe single biomolecules and obtain critical information for their detection and analysis. However, the major drawbacks of this include, but are not limited to, potential toxicities associated with the unavoidable release of nanoparticles into the environment, miniaturization-induced unreliability, lack of automation, and difficulty of integrating the nanostructured-based biosensors, as well as unreliable transduction signals from these devices. Although the field of biosensors is vast, we intend to explore various nanotechnology-enabled biosensors as part of this review article and provide a brief description of their fundamental working principles and potential applications. The article aims to provide the reader a holistic overview of different nanostructures which have been used for biosensing purposes along with some specific applications in the field of cancer detection and the Internet of things (IoT), as well as a brief overview of machine-learning-based biosensing. The concept of biosensing is deeply embedded within most organic life forms, and from an evolutionary point of view, this has enabled them to survive harsh environments and predators. Common examples of this include augmented olfactory abilities of ca-nines, the electrosensitive nature of sharks, and toxin-sensing capabilities of certain algae ,2,3. AccAdvances in nanotechnology have allowed us to build structures or devices in the nanoregime, such as nanoparticles, nanotubes, nanorods and nanowires, which can directly probe and interact with the very biomolecules we intend to detect using biosensors. Such devices display unique properties, such as excellent electrical conductivity, tunable optical, electrical, and magnetic properties and show great promise for faster response and higher sensitivity at the device in comparison with conventional biosensors. Therefore, they can be exploited for a variety of bioengineering applications ranging from biosensors to drug delivery. Nanotechnology has had a significant impact on the field of disease detection, especially by using electrochemical, electromechanical, resonance, thermal, magnetic, and optical techniques. Nano-biosensors have advanced the ability to identify specific analytes and obtain detailed information regarding biomolecular profiles of various diseases. Accurate sensing and analysis of specific biomarkers has led to the development of advanced biosensor systems which are capable of sensing localized micro-environmental fluctuations, thus providing an indication of the disease, disease progression, and therapeutic assessment. However, in spite of their exciting properties, these nano-biosensors are plagued with certain disadvantages, such as drift, fouling, nonspecificity, and displaying irreproducible and nonuniform transduction signals.There are a number of highly informative reviews in the literature which are an excellent resource for an in-depth understanding of certain specific nanostructures for biosensors ,20,21,22The following sections of this review article will provide an overview of existing nano-biosensors along with their fundamental working principles and certain applications of such devices in varied biological fields. The article begins with a very brief discussion of various types of nano-biosensors and their applications. Following this, we provide a description and applications of thin-film-based biosensors. Next, a highly detailed description of nanostructure-based biosensors is also provided. In this section, we mainly describe sensors comprised of gold nanoparticles, carbon nanotubes, graphene, and quantum dots. A plethora of sensor applications is also discussed with literature references. After this, we provide a discussion of the impact nano-biosensors have had on the field of cancer research and low-power sensors for the Internet of things, including future prospects of this technology. Finally, a brief review of machine-learning-based biosensors is also provided to conclude the review.Nano-biosensors are a class of sensors which are used to observe, measure and analyze biological events using sensors which have been built using the techniques of nanotechnology. They are mostly built using various forms of quantum dots, nanoparticles, nanowires, and nanofilms. Most naturally occurring biological systems such as viruses, membranes, and protein complexes and their interactions take place in the nanometer regime. This makes devices whose dimensions are in the nanoscale ideal candidates for biomedical and bioanalytical applications to obtain higher degrees of sensitivity, specificity, and faster response times compared to the traditional methods of biosensing. These include a multitude of varied applications such as using amperometric nanodevices for enzymatic detection of glucose, quantum dots as fluorescence agents for the detection of binding, and even using bio-conjugated nanomaterials for specific biomolecular detection. For example, colloidal nanoparticles have been conjugated with antibodies for highly specific immunosensing purposes. Similarly, the electronic and optical properties of metal nanoparticles have been exploited for DNA/RNA detection and analysis. Nanomaterials/structures such as quantum dots, nanoparticles, and nanotubes are the key components of any nano-biosensor system. Based on these structures, devices such as nanosensors, nanoprobes and other miniaturized systems have revolutionized the field of chemical and biosensing. Such nanodevices have been specifically designed to exhibit high response times and ultralow power requirements. Nanomaterials such as metal nanoparticles, oxide nanoparticles, magnetic nanomaterials, carbon materials, quantum dots, and metallophthalocyanines have been used to improve the electrochemical signals of biocatalytic events that occur at the electrode/electrolyte interface. Functionalized nanoparticles that are bound to organic molecules have been developed for use in biosensors. The synthesis of such nanostructured materials and nanodevices involves a varied number of techniques, and the selection of a synthesis technique depends on the material of interest or the type of nanomaterial such as 0D, 1D, 2D, their sizes, and the desired quantity ,24,25. F2, TiO2, Al2O3, and Si3N4. These layers are crucial to the practical deployment of thin-film-based biosensors and drug delivery systems. Such layers are often exploited for their superior electrical, optical, magnetic, and mechanical properties in comparison with their bulk counterparts. For example, Sokolov et al. demonstrated that a PDMS thin-film utilized as a miniature pressure sensor displayed a recovery time which was ~50 times faster than a pressure sensor which comprised of a bulk PDMS layer [2 substrates. Functionalization using organic thin films is an equally important aspect of thin-film-based biosensor technology. The functionalization process essentially consists of depositing a thin layer of organic films such as a variety of thiol molecules, proteins, and nucleic-acid molecules. The selection of the appropriate surface chemistry is crucial to the uniform formation of the organic films and depends on the specific material to be activated. Silane molecules are often used to functionalize inorganic surfaces, such as glass. Numerous examples of similar functionalization techniques can be found in these literature references. The working principle of thin-film-based biosensors is based on the selective adsorption of analyte molecules on a functionalized thin film. These biosensors act as physicochemical  transducers, which convert the signal resulting from the recognition of the biological analyte into another form of a measurable signal. A plethora of thin-film-based biosensors can be found in literature references. These are comprised of complex structures of thin films, which give enormous functionalities to the sensors. The thin films are made from either organic and/or inorganic materials, such as metals, glass, polymers, silicon, or metal oxides. Specific structures of biological molecules can also be used as thin films. The most crucial part of such biosensors is the analyte-sensitive layer, i.e., the layer which reacts to the biomolecule. On this surface, atomic interactions and surface free energies and forces are different from the bulk of the material, and the analyte-specific reaction starts here. Surface activation can be necessary to immobilize biological analytes on sensitive layer. For this purpose, self-assembled monolayers (SAM)-enabled surface-modification techniques are the most widely used . Thin fiMS layer . The mosNanostructures are attractive options for biosensor applications due to their observable quantum effects and large surface area. Exploiting these unique properties potentially enables us to design biosensors with improved characteristics compared to their traditional counterparts. Essentially, such nanostructures can be realized in 0D , 1D  or 2D . The following sections will provide a broad overview of the most widely used nanostructures for biosensing purposes.2 or MnO2 nanoparticles, polymeric NPs, and semiconductor NPs such as CdS nanoparticles have been integrated with microstructures for efficient and sensitive biosensing [The recent advances in nanotechnology have allowed for cheap and rapid synthesis of nanoparticles (NPs), and these NPs have demonstrated augmented sensitivity against certain analytes and have therefore been extensively used for biosensing purposes. For example, metallic NPs such as gold and silver nanoparticles, dielectric NPs such as SiOosensing ,33,34,35AuNP-based optical biosensors: As the name suggests, these devices are designed to realize a measurable transduction between the presence or change in concentration of the analyte of interest and the optical properties of the biosensor. The fundamental principle behind gold nanoparticle assisted biosensing is the collective oscillation of plasmons in response to incident electromagnetic (EM) waves. An example of such a phenomenon is surface plasmon resonance (SPR), where the interaction between the incident EM waves and the conduction-band electrons of Au is used for probing surface characteristics of the same. This interaction results in the resonant coherent oscillations of the surface conduction electrons of the metal, and the characteristics of these oscillations is a function of the concentration of the analyte of interest, which is present on the surface. Generally, the specific binding of biomolecules on the surface of metals results in a change of the dielectric constant of the surrounding medium, which then causes a change in optical characteristics of any EM wave which is incident on the metallic surface. This change is proportional to the concentration of the coated biomolecules, and therefore, accurate measurements of the reflected EM wave provide relevant information regarding the concentration of the analyte of interest. Englebienne was one of the first researchers to report a red-shift in the SPR resonant frequency of gold particles coated by a monoclonal antibody [antibody . For theSome significant examples include the work of Lin et al. who used the SPR technique and demonstrated an optical-fiber-based biosensor, sensitive to organophosphorous pesticides . The preAuNP-based electrochemical biosensors: Electrochemical biosensors are devices which are designed specifically for transduction of biochemical signals into measurable electrical signals. These sensors have been widely investigated in the last couple of decades due to their relatively simple fabrication process and low-cost detection capabilities. As mentioned above, the excellent electrical properties, biocompatibility, and catalytic properties of AuNPs make them an attractive component of electrochemical sensors. Integrating AuNPs with existing electrochemical sensors leads to enhanced transduction signals due to an “amplified” electrode surface and augmented electron transfer between redox centers in proteins. AuNPs have also been used as catalysts for electrochemical reactions. The role of AuNPs can be broadly classified as (1) electron transfer mediators and (2) immobilization platforms.Usually, the active center of most biomolecules (for example a protein) is surrounded by a thick layer of electrically nonconducting shells, which impedes the flow of electrons between the electrically active center and the probing electrode, which leads to a poor output electrical signal. Natan et al. demonstrated for the first time, the amplification of electrical signals due to augmented electron transfer between the active center and the electrode . SimilarAuNPs are ideal for immobilizing biomolecules, in contrast to their bulk counterparts, since biomolecule adsorption on bulk materials has often led to degradation of their properties. For example, adsorption of protein biomolecules on the surface of bulk materials has often led to denaturation. Adsorption of such bio-molecules on AuNP surfaces has shown no signs of degradation due to the biocompatibility and high surface energy of gold. Additionally, due to their inherently higher surface area than their bulk counterparts, AuNPs can immobilize a far greater number of protein molecules, which therefore allows the realization of more sensitive biosensor devices. For example, Andreescu et al. utilized immobilized periplasmic glucose receptors on AuNPs and measured their electrical properties as a function of glucose concentration to develop a novel glucose sensor . SimilarIn addition to the above-mentioned applications, AuNPs have been used in conjugation with other nanostructures such as carbon nanotubes (CNTs) and graphene to further enhance their immobilization and binding capabilities. For example, Cui et al. have built an electrochemical biosensor based on the conjugation of AuNPs and CNTs .2O2 [Although gold is an inert element, small-sized AuNPs have demonstrated their ability to act as a catalyst. This property of AuNPs has been widely exploited for biosensing purposes. Such properties of AuNPs are generally believed to be a result of quantum-mechanical effects arising due to their much augmented surface-to-volume ratio. AuNPs have therefore been effectively utilized to reduce overpotentials of crucial electrochemical reactions as well as engineer the reversibility of certain redox reactions. For example, Tuener et al. demonstrated that 1.4 nm-sized AuNPs provided catalyst-like features for oxidation of styrene by dioxygen . Further2O2 . AnotherAuNP-based piezoelectric biosensors: The final category of AuNP-based biosensors which will be explored in this article are AuNP-based piezoelectric biosensors. In these sensors, any mass changes initiated due to biological events are detected by the quartz crystal microbalance (QCM) method, which is based on the piezoelectric effect. High-density AuNPs with enhanced surface-to-volume ratios are integrated with piezoelectric biosensors to amplify the inherently weak signals. For example, Jiang et al. demonstrated a microgravimetric DNA biosensor integrated with AuNPs [Escherichia coli detection [th AuNPs . In thisth AuNPs . Other eetection ,58. Besietection . Literatetection . This hyThere has been significant research and advancement in the field of carbon-based nanomaterials in the last couple of decades. The most widely studied and utilized carbon nanomaterials include carbon nanotubes (CNT), graphene  and graphene quantum-dots. Due to their specific structure and electronic configuration, their electromechanical properties are highly attractive for transduction purposes. Similar to other nanostructures, an augmented surface-to-volume ratio aids in significantly more number of binding sites in comparison with bulk materials. Due to such properties, carbon-based materials such as graphene and carbon nanotubes have been integrated with CMOS transistor technology to develop modified transistors and also for biosensing purposes. A more in-depth discussion of carbon-based nanomaterials and their applications in biosensing can be found here ,62,63,64Carbon nanotubes (CNTs) are cylindrical structures comprising of “rolled-up” sheets of a single-layer of carbon atoms. Depending on their structure, they can be classified as either single-walled or multiwalled. After their discovery in 1991 , CNTs haCNT-based electrochemical biosensors: As mentioned above, electrochemical biosensors are designed for transduction of biochemical signals into measurable electrical signals. These sensors have been widely used due to their low cost, ease of fabrication, and use as well as small footprint. Like AuNPs, CNTs have the ability to enhance the electron transfer which make them ideal additions to electrochemical biosensors. CNTs display a high surface-to-volume ratio, augmented sensitivity, electrical conductivity, and chemical stability, as well as high electrocatalytic effect, which make them ideal candidates for biosensors which require enzymatic reactions for accurate sensing. Therefore, a wide variety of CNT-based electrochemical sensors have been developed in the last two decades. For example, Wang et al. developed such devices for detecting metabolites and protein biomarkers [omarkers . CNTs haomarkers . Using somarkers . Santos omarkers . Similaromarkers ,71. Zelaomarkers . Some adomarkers ,74. Baseomarkers . Antiochomarkers .CNT-based optical biosensors: As describe in previous sections, optical biosensors are designed to realize a measurable transduction between the presence or change in concentration of the analyte of interest and the optical properties of the biosensor. Lubbers and Oppitz were the first to develop an optical biosensor for CO2, O2, and alcohol detection [etection . Since tetection . Heller etection . CNTs fuetection . Using setection . In thesetection ,83.2g−1, and the Young’s modulus is 1 TPa with an intrinsic mobility of 2 × 105 cm2v−1s−1. The thermal conductivity of graphene has been determined as 5 × 103 Wm−1K−1. It is optically almost transparent with a measured transmittance of 97.7%, and it is extremely conductive with a conductivity of ~104 Ω−1cm−1. Amongst its widespread applications, graphene has been mostly used to build high-speed electronic devices for storage and energy harvesting. It has been used to fabricate high-frequency transistors, photodetectors, and biosensors for a plethora of applications such as DNA sequencing. Graphene was first theoretically explored by P.R. Wallace in 1947  and thenGraphene-based electrochemical biosensors: As mentioned above, due to its excellent electrical properties, graphene can be integrated with the electrodes of electrochemical biosensors for enhanced biosensing. In addition to graphene’s augmented conductivity, it is chemically stable, has low cost, and is electrochemically inert. However, in certain cases, graphene has also been used as a catalyst for numerous biochemical redox reactions. In such biosensors, enzymes are immobilized on the graphene layer, which are used for specific analyte-recognition purposes. The immobilization can be realized using a variety of techniques including adsorption technique, covalent binding, electro-polymerization, and layer-by-layer immobilization. Amongst the variety of applications of graphene-based electrochemical biosensors, the most important are the detection of heavy metals, phenols, pesticides, and other pollutants such as hydrogen peroxide or microorganisms for environmental-monitoring purposes. Electrochemical sensors, based on principles of potentiometry and voltammetry, have been widely pursued to detect the presence of heavy metals and are being pursued widely due to their low cost, portability, reduced response time, and augmented sensitivity. The literature shows that electrochemical sensors for detecting heavy metals make use of noble metals such as Au and Pt for electrodes or different forms of carbon [2+ (1.5 nM) and Pb2+ (0.4 nM), based on principles of square-waver voltammetry analysis techniques [2+ and Pb2+ to further lower the limit of detection. Zhou et al. developed a biosensor for detecting Pb2+ using graphene-quantum-dot structures. These modified quantum dots were fabricated from graphene oxide, which were powdered into smaller pieces and chemically reduced using the green’s technique with polystyrene sulfonate and L-ascorbic acid [2+. Another highly sensitive and selective technique of detecting Hg2+ is by using graphene functionalized with aptamers [2O2. Song et al. reported a similar device which comprised of a multilayer electrode, consisting of molybdenum-disulfide–graphene and horseradish peroxidase for an ultralow limit of detection of H2O2 [Escherichia coli (E. coli) has been previously detected using graphene-based biosensors using functionalized graphene layers. The literature suggests that probing electrodes which comprise of a hybrid graphene and CNT layer, as well as the presence of graphene oxide, provides a higher probability of E. coli capture compared to bare graphene [E. coli detection, which does not involve the use of antibodies is based on using the adsorption of the slightly negatively charged E. coli on the surface of the p-type graphene. Another bacterium which has been similarly detected (using either antibodies or aptamers) using graphene-based biosensors is Staphylococcus aureus [f carbon . Specifichniques . In thisbic acid . Anotheraptamers . The limaptamers . Graphenaptamers ,92. Anotaptamers . Recentlaptamers . Some otaptamers . The litaptamers . The priaptamers . Anotheraptamers . Graphenaptamers . The addaptamers . Anotheraptamers . Generalaptamers . This co of H2O2 . Escherigraphene . In othegraphene . Anothers aureus .Quantum dots are colloidal nanostructures mostly built using semiconductor materials belonging to the groups of II–VI, III–V, or IV–VI in the modern periodic table. Due to quantum-mechanical effects, quantum dots display opto-electrical properties which are significantly different that conventional bulk materials. These properties make quantum dots attractive candidates for biosensing purposes. Alivisatos and Nie were the first to develop a quantum-dot biosensor and imaging system based on fluorescence in 1998 ,108. SinQuantum-dot-based fluorescent biosensors: As mentioned above, its high sensitivity and enhanced stability as well as abilities to measure different analytes simultaneously have led to significant development of quantum-dot-based fluorescent biosensors. Fluorescence-based resonant energy transfer is the most widely used technique for quantum-dot-based biosensors. The advantage of the resonant technique is that it enables detection of target biomolecules without any requirement of washing and separation steps. Additionally, high SNR  and highly sensitive techniques such as single-molecule detection methods have been used for quantum-dot-based biosensors for the detection of biomolecules such as DNAs, DNA methylation, and numerous enzymes. For example, Zhang et al. developed a DNA assay where liposomes encapsulated hundreds of quantum-dots to form hybrid complexes to enable binding of target DNA. This technique was used to accurately and simultaneously detect genetic sequences of HIV-1 and HIV-2 at 10–18 molar concentrations [Helicobacter pylori-specific DNA [2O2, Tang et al. demonstrated a paper-based biosensor for accurate detection of carcinoembryonic antigen with a limit-of-detection of ~6.7 pg/mL [trations . Shamsipific DNA . Krull eific DNA . This deific DNA . Using fific DNA . Zhang eific DNA . Ho et aific DNA . Wang etific DNA . Sang anific DNA . Hildebrific DNA . Based o.7 pg/mL . Using s.7 pg/mL . Kim et .7 pg/mL . Tyrakow.7 pg/mL . Li et a.7 pg/mL . Zhang e.7 pg/mL . The sam.7 pg/mL . Using f.7 pg/mL .Quantum-dot-based bioluminescent biosensors: A major bottleneck to the practical implementation of fluorescent biosensors based on quantum dots is the inherent requirement of appropriate illumination sources. Additionally, such sensors suffer from high background noise signals due to direct excitation of the acceptor fluorophore. This can be solved by using a bioluminescence resonance-energy transfer technique where a bioluminescent luciferase acts as the energy donor which acts as the catalyst for the oxidation of the substrate which generates the emission light and which can then be transferred to the acceptor to complete the bioluminescence resonance-energy transfer process. For example, Shen et al. demonstrated sensitive and selective detection of enrofloxacin using a quantum-dot-based bioluminescent biosensor [iosensor . Additioiosensor .Quantum-dot-based chemiluminescent biosensors: These devices are based on the principle of emission of light due to a chemical reaction. Quantum dots are exploited for their catalytic properties which can enhance redox chemiluminescent reactions and thereby improve the transduction signal. Therefore, quantum-dot-based chemiluminescent biosensors have been widely developed for their low background noise and high sensitivity. For example, Ju et al. built a quantum-dot-based chemiluminescent biosensor for sensitive detection of a carcino-embryonic antigen with a limit of detection in the range of 24 fg/mL [24 fg/mL . Based o24 fg/mL . Similar24 fg/mL .Quantum-dot-based photo-electrochemical biosensors: In these biosensors the analyte-dependent photoexcitation is the source of transduction energy, which is measured for sensing purposes. Such devices are generally easy and cheap to build and are designed to be portable for practical purposes. They have been used to build highly sensitive sensors for detecting DNAs and proteins. For example, Ju et al. developed photo-electrochemical biosensors based on quantum dots, functionalized with ZnO nanosheets for highly sensitive detection (~0.93 fM concentration) of DNA [−7 g/L). Chen used CdS quantum dots with TiO2 to realize modified ITO electrodes [) of DNA . Zhu et ) of DNA . The limectrodes . Finallyectrodes .The different nanostructures utilized for biosensing, along with their transduction mechanism as well as the limit of detection can be summarized in the In the previous sections, the article provided an extensive overview of biosensors comprising of nanofilms/structures and their many applications. In this section, we provide a brief review of the application of such biosensors specifically in two extremely important fields of research: (1) cancer diagnostics and (2) low-power, portable sensing techniques for Internet of things (IoT) applications.Due to its high mortality rate, cancer has been the subject of widespread and incessant research over the globe. On account of their enhanced sensitivity, selectivity, ease-of-use, and superior analytical performance for rapid sensing, nanostructure-based biosensors are highly attractive candidates for cancer detection. The following sections will provide a brief literature survey of nanostructure-based biosensors and biosensing techniques which employ nanostructures for cancer diagnosis.CNT-based biosensors: Feng et al. developed a paper-based bipolar electrode, functionalized with multiwall CNTs for sensitive electrochemiluminescent detection of prostate specific antigen(PSA) [gen(PSA) . Baj-Rosgen(PSA) . Ovádekogen(PSA) . Liu et gen(PSA) . Park etgen(PSA) . Zheng egen(PSA) . Fayazfagen(PSA) . Shobha gen(PSA) . Lerner gen(PSA) . Abdolahgen(PSA) . Liu et gen(PSA) . Veetil gen(PSA) . Malhotrgen(PSA) . Wan et gen(PSA) . Arkan egen(PSA) . Zerda egen(PSA) . Wang etgen(PSA) .Quantum-dot-based biosensors: Ho and Wilner et al. demonstrated a quantum-dot-based biosensor for the detection of miR-141 in prostate cancer [e cancer . Zhang ee cancer . Kim et e cancer . Jie et e cancer .Surface-plasmon resonance-based biosensors: Surface-plasmon resonance (SPR)-based biosensors have been actively used for detecting cancer biomarkers in serum samples [ samples . Using s samples . Carcino samples ,158,159. samples . Another samples . Jang et samples . Similar samples . The lim samples .Quartz crystal microbalance (QCM)-based biosensors: QCM-based biosensors integrated with nanoparticles have been used for sensitive detection of PSA and PSA–alpha 1-antichymotrypsin biomarkers, with a limit of detection measured in the range of 0.29 ng/mL [29 ng/mL . QCM tec29 ng/mL . Wang et29 ng/mL . QCM bio29 ng/mL . Similar29 ng/mL .Magnetic nanoparticles-based biosensors: Functionalized magnetic nanoparticles are vital for noninvasive and highly sensitive detection of cancer cells. Kumar et al. utilized magnetic nanoparticles, functionalized with target-specific peptides for enhanced tumor uptake and more pronounced silencing effects [ effects . These m effects ,179,180.With the meteoric rise of the Internet of things (IoT) in the last two decades, humanity is on the verge of witnessing the advent of a new digital nervous system for the world. With the practical deployment of an interconnected network of cameras, microphones, and a plethora of sensor and actuator systems, we seem to be inching toward a truly “smart” society. The earliest realization of the IoT was in 1982 when a group of local programmers at Carnegie Melon University connected a Coca-Cola machine to the internet to check if there was a drink available in the machine and if it was cold. With the term “Internet of things” being coined in 1999, the practical implications of this technology have been widespread in the last twenty years, and it has evolved immensely. By the year 2013, the IoT became an amalgamation of various technologies, including the internet, wireless communication, GPS, embedded systems, and MEMS devices. The latest advances in the IoT technology include development of smart wearable electronics for health monitoring, smart homes, pre-integrated IoT platforms, merging of artificial intelligence, and machine-learning algorithms with stand-alone devices and implementation of low-cost and power-efficient sensors and sensor-networks.At the backbone of the entire IoT framework lies a variety of sensors and sensor systems that collect diverse data and share it across the network of interconnected smart devices. This makes it possible for these devices to operate autonomously and improve the effectiveness and functionality of the vast IoT network. Some of the critical sensors which are being extensively used for these purposes are temperature, proximity and pressure sensors, water and air-quality monitoring sensors, and IR sensors. However, the practical realization of such an omnipresent and densely interconnected system demands the availability of low-power sensors and sensor systems for energy-efficient device operation and communication between the smart devices. For example, continuous air quality monitoring and asset tracking requires the sensors to be battery operated and deployed in remote areas of the world. Furthermore, to minimize energy consumption, most of these sensors are designed to typically operate in “sleep” or “stand-by” mode where it consumes very low power and record data only in the presence of a stimulus or according to a predetermined operation protocol. Research intended for the development of low-power sensors and sensor systems for IoT-based applications has been actively pursued by a significant proportion of the scientific community in the last couple of years and has led to major advancements in the field of nanotechnology-based sensor and sensor systems. The following section provides some key references across this field.2 nanowire gas sensors for IoT and portable applications [2 core-shell heterojunctions [2 thin films [2 sensor based on Si nanomembranes [Chikkadi et al. demonstrated the ultra-low-power operation of self-heated, suspended carbon-nanotube gas sensors . Ngoc anications ,183. Liuunctions . Han et in films .Cho demoembranes . Alreshaembranes ,188. Mamembranes . Long etembranes . Weiss pembranes . Villaniembranes . Kassal embranes . Laubhanembranes . Kuo et embranes . Kamakshembranes . Garulliembranes . Kim et embranes ,205,206.embranes ,212,213.IoT sensors in the field of healthcare is also an active area of research. Beach et al. presented an ultra-low-power ECG monitor integrated with the SPHERE IoT platform . Xican eResearchers worldwide are highly invested in developing state-of-the-art sensor-nodes/systems and system architecture catered to IoT applications. For example, Hayashikoshi and Gogoi proposed a low-power multi-sensor platform for IoT applications ,219. TreAlthough there has been a significant progress in the field of nano-biosensors in the last decade, such devices still typically suffer from certain disadvantages such as electrical noise, random quantum effects, limited specificity, and reduced stability. These issues have proven to be a significant bottleneck to their successful commercialization. One of the emerging technologies which is being used to mitigate such deficiencies is machine learning. From the perspective of biosensor applications, machine learning can be broadly described as an algorithmic approach for analyzing sensor data and extracting useful information by means of statistical techniques . MachineEscherichia coli, by analyzing data obtained by a colorimetric biosensor [Escherichia coli and Salmonella typhimurium by using silver nanowires on polyimide substrates [Escherichia coli and Bacillus subtilis [Guselnikova et al. demonstrated the use of convolutional neural networks for surface-enhanced Raman spectroscopy for detection of oligonucleotide damage on gold gratings . Using biosensor . Kim et iosensor . Ballardiosensor . Luo et iosensor . Gonzaleiosensor . By usinbstrates . Albrechbstrates . Tsutsuisubtilis . Zeng etsubtilis . Besidessubtilis . Tatarkosubtilis . Adak etsubtilis . Yan et subtilis .The advent of nanotechnology has undoubtedly aided the field of biosensors to reach new heights. Sensor parameters such as limit of detection, accuracy, and reliability have been shown to improve by incorporating nanomaterials/nanostructures for biosensing purposes. Such novel biosensors have been demonstrated to display single-molecule detection, significantly amplified transduction outputs as well as allowed rapid detection of intended analyte. These properties have helped remove certain bottlenecks which have hitherto prevented the practical implementation of biosensors. However, this technology is also plagued by certain disadvantages such as the inevitable release of nanoparticles into the environment. Additionally, although quantum effects result in very high sensitivity, they are often the source of randomized noise and background signal. Therefore, such sensors have displayed cross-sensitivity, nonlinear, and nonrepeatable response upon exposure to certain analytes. Furthermore, materials such as graphene while highly attractive for biosensing purposes have not yet been successfully mass fabricated. These limitations still need to be carefully addressed before the entire world can successfully harness the amazing properties of nanotechnology in biosensors. In conclusion, this review article aims at providing the reader a detailed overview of some of the most commonly used biosensors which have been realized by nanotechnology-enabled thin-films and miniaturized structures. These include thin-films, gold nanoparticles, carbon nanotubes, graphene, and quantum-dots. Numerous examples from literature have also been cited to provide the applications of such biosensors. Furthermore, the article also describes the influence of such biosensors specific to the vital field of cancer research. A future perspective with respect to low-power sensors for the Internet of things including future commercial prospects of this technology as well as the role of machine-learning techniques in biosensing has also been provided.


History of previous TB treatment was observed in a majority of the cases (87.7%). Nearly one-third of DR-EPTB cases (33%) had unfavourable treatment outcomes, with loss-to-follow-up  or death  being the most common unfavourable outcomes. In the adjusted analysis, weight band 31–50 kilograms  and h/o previous TB  were mainly associated with unfavourable outcomes. TB elimination efforts need to focus on all forms of TB, including DR-EPTB, leaving no one behind, in order to realise the dream of ending TB. Extrapulmonary drug-resistant tuberculosis (DR-EPTB) poses a formidable diagnostic and therapeutic challenge.Besides associated with high morbidity, it is a major financial burden for the patient and the health system. In spite of this, it has often been neglected as it does not “pose” a visible public health threat. We study clinical profiles, treatment outcomes, and factors associated with unfavourable outcomes among DR-EPTB patients under programmatic settings in New Delhi, India, and evaluate how this could impact TB elimination. A retrospective analysis of all DR-EPTB patients registered at three nodal DR-TB centres in Delhi in 2016 was carried out. Of the 1261 DR-TB patients registered, 203 (16%) were DR-EPTB, with lymph nodes  being the most common site, followed by bone . Nearly 29% ( Mycobacterium tuberculosis (MTB), the causative agent, usually affects the lungs (pulmonary TB/PTB). However, MTB may spread through lymphatic or hematogenous routes to virtually any organ in the body, resulting in extrapulmonary TB (EPTB). The most common sites of EPTB infection include peripheral lymph nodes, pleura, genitourinary sites, bones and joints, abdomen , and the central nervous system.Tuberculosis (TB) remains the top infectious killer, ranking above HIV/AIDS, with 10.0 million cases and 1.4 million deaths in 2018 [While EPTB has existed for millennia, pulmonary TB has remained the prime focus of global TB control programmes. EPTB is often less contagious than PTB, and is therefore overlooked even though it constitutes about 15% of all forms of TB, amounting to nearly 1 million incident cases notified in 2018, as per the WHO Global TB report [In the present era of HIV pandemic coupled with global emergence of multidrug-resistant TB (MDR TB) and extensively drug-resistant TB (XDRTB), drug-resistant EPTB (DR-EPTB) presents a real and new public health challenge that has yet to receive serious attention. While drug resistance in PTB has been extensively studied, DR-EPTB has been neglected. Several systematic reviews and individual patient meta-analysis have reported treatment outcomes of MDR-TB, without disaggregated outcomes of DR-EPTB ,3,4,5. TIndia continues to have the highest number of TB cases in the world, with nearly 2.69 million cases in 2018 . It alsoIndia aims to eliminate TB by 2025; however, this goal will remain unachieved if EPTB, especially the drug-resistant cases, continues to be ignored . CompareA better understanding of this small yet significant group of patients is necessary to design effective interventions that might help reduce morbidity and mortality and improve treatment success rates. When the global community talks about TB elimination, it talks about TB per se; however, most interventions and strategies are focused on pulmonary TB. The strategy and milestones to end the global TB epidemic include all diagnosed TB cases and latent TB cases , hence wIndicators such as TB treatment coverage, treatment success rates, the percentage of TB-affected households that experience catastrophic costs due to TB and drug-susceptibility testing (DST) coverage for TB patients is difficult to measure, and sustainable development goals (SDGs) cannot be achieved without giving due importance to DR-EPTB .To address these gaps, we carried out this operational research in order to study the demographics, clinical profiles, and treatment outcomes of patients with DR-EPTB registered at three selected DR-TB nodal centres in Delhi in 2016, and explored risk factors associated with unfavourable treatment outcomes. This is a retrospective cohort study involving a record review of routine program data.Delhi is the capital of India inhabited by 18.6 million people, with a large number of migrants. It has one of the highest population densities of 11,320 persons per square km, and a literacy rate of 86% . Delhi hThe Programmatic Management of Drug-Resistant TB (PMDT) services were launched in India in 2006 and obtained full geographical coverage in 2013. PMDT services started in Delhi in 2008 with a culture and drug susceptibility testing (C & DST) laboratory located at the state-owned Intermediate Reference Laboratory (IRL). Other tests, such as the cartridge-based nucleic acid amplification test (CBNAAT) and line probe assay (LPA), are also available at the IRL. PMDT services are provided through 25 chest clinics and four Nodal DR-TB centres in Delhi. Since 2018, all the chest clinics in Delhi have been designated as district DR-TB centres. Microbiological confirmation of disease for DR-EPTB patients is preferred for diagnosis. This is done using either CBNAAT or culture or both. However, clinical diagnosis is also reached with the help of fine needle aspiration cytology (FNAC), histopathology findings, or interferon gamma release assays (IGRA), along with other signs and symptoms of TB, especially among those not responding to the WHO drug-sensitive ATT regimen. The patients are usually diagnosed at the district DR-TB centres or nodal DR-TB centres, and a sample, if available, is sent to the IRL along with a filled form requesting C&DST. Patients are started on the conventional MDR regimen at the Nodal DR-TB centres after pretreatment evaluation, as per NTP guidelines. Further follow-up and management is done at the district DR-TB centres. The diagnostic algorithm, which is common for both pulmonary and EPTB, is given in The conventional RNTCP regimen for MDR-TB is given to the patients with DR-EPTB, i.e., intensive phase with six drugs for 6–9 months , followed by a continuous phase with four drugs for 18 months  as per RNTCP PMDT guidelines 2016 . The patClinical monitoring is mainly based on clinical parameters such as weight gain, change in the size of lymph nodes/lesions, the appearance of new lymph nodes/lesions and monitoring of other EP sites located deep in the body by ultrasound, magnetic resonance imaging, computed tomography scan, and ESR (erythrocyte sedimentation rate). Surgery is considered in the absence of response to chemotherapy despite 6–9 months of treatment ,19.Treatment outcome definitions used by the RNTCP are given in Regular monitoring of side effects of drugs is done by blood tests , audiometry, thyroid function tests, ocular examinations, ECG for QT prolongation and other tests, if needed.Box 1Cure: Treatment completed as recommended by the national policy without evidence of failure, and three or more consecutive cultures taken at least 30 days apart during CP are negative, including culture at the end of treatment.Treatment completed: Treatment completed as recommended by the national policy without evidence of failure, but no record that three or more consecutive cultures taken at least 30 days apart are negative after the intensive phase.Treatment success: This is a combination of cure plus treatment completed.Treatment failure: Treatment terminated or a need for permanent regimen change of at least two or more anti-TB drugs in CP because of the lack of microbiological conversion by the end of the extended intensive phase or microbiological reversion in the continuation phase after conversion to negative or evidence of additional acquired resistance to FQ or SLI drugs or adverse drug reactions (ADR).Death: A patient who dies for any reason during the course of treatment.Treatment lost-to-follow-up: A patient whose treatment was interrupted for one month or more for any reasons prior to being declared as failed.Not evaluated: A patient for whom no treatment outcome is assigned.Regimen changed: A TB patient’s need for permanent regimen change of at least one or more anti-TB drugs prior to being declared as failed.Treatment stopped due to adverse drug reactions: A patient who develops adverse drug reactions and cannot continue the M/XDR-TB treatment in spite of the management of adverse drug reactions as per the defined protocols and a decision has been taken by the DR-TB Centre committee to stop treatment.The study was conducted in three designated Nodal DR-TB centres under RNTCP in the state of Delhi.The study population included all DR-EPTB patients registered from 1 January 2016 to 31 December 2016 in the three selected nodal DR-TB centres in Delhi. These patients were admitted to a common TB hospital and initiated on a conventional MDR-TB regimen.Those with associated pulmonary TB or on ITR  or XDR treatment regimen were excluded from the study; there were only three cases of associated pulmonary TB.A list of all eligible DR-EPTB patients registered in 2016 at the selected nodal DR-TB centres was prepared. The principal investigator (SL) extracted data from the patient treatment cards and PMDT registers from September 2018 to February 2019 into a structured data collection instrument. Socio-demographic and clinical variables like PMDT TB number, date of registration, nodal DR-TB centre, age, sex, type of disease (primary/secondary MDR), site/s involved, history of previous TB treatment, site involved in previous TB episode, basis of diagnosis, resistance to drugs, comorbidities like HIV, diabetes, initial weight (in kilograms), final weight (in kilograms), adverse drug reaction, number of missed doses, treatment outcome see  and datep < 0.2 on univariable analysis were included in the final regression model. Unfavourable outcomes were defined as death, loss to follow-up, treatment failure, not evaluated, regimen change, or stopped treatment due to reasons other than adverse drug reactions. Favourable outcome was defined as treatment completed and cured.Data collected were double-entered and validated using EpiData version 3.1, and discrepancies were corrected by referring to the data collection forms or the original patient files. Data analysis was carried out using EpiData analysis version 2.2.2.183  and STATA version 13.0. Number and proportion were used to summarise categorical variables, and mean (standard deviation) or median (interquartile ranges (IQR)), as applicable, were used to summarise continuous variables. A chi-square test was performed to find the association of various socio-demographic and clinical variables with the treatment outcome. Binomial regression was done to explore the predictors of unfavourable treatment outcomes after controlling for confounders. The strength of association was expressed using relative risks (RRs) and 95% confidence intervals (95% CI). Variables with Administrative approval was obtained from the State TB Office, Delhi, India. Ethics approval was obtained from the Ethics Advisory Group of the International Union Against Tuberculosis and Lung Disease, Paris, France. Names of patients were not captured. The PMDT registration number was used to identify patients. Of the total 1261 DR-TB patients registered in the three selected DR-TB sites in Delhi in 2016, 1058 (84%) were pulmonary and 203 (16%) were DR-EPTB cases, all of whom were included in the study. ).Most patients were female , aged 15–44 years . Around two-thirds of the patients  weighed less than 50 kilograms. Lymph node  was the most common site of involvement, followed by bone and joint . A large majority of patients had a previous history of TB . CBNAAT was the basis of diagnosis in 173 patients (85.2%) and LPA in 20 (9.9%) cases .n = 58) experienced at least one ADR, with severe vomiting , joint pain , behavioral disorder  and hearing loss  being the most commonly observed ADRs (Nearly 28.6% (ved ADRs .The median (IQR) number of days from diagnosis to registration for treatment was 15 ,23,24,25n = 134). Of the 69 (34%) patients with unfavourable treatment outcomes, most of them were due to LTFU  or death   .p-value = 0.02), DR-TB centre  and history of previous TB  were significantly associated with unfavourable treatment outcomes  one in every six registered DR-TB patients has DR-EPTB, (ii) lymph node is the most common site of involvement, followed by bone, in DR-EPTB patients, (iii) one-third of all DR-EPTB cases had unsuccessful treatment outcomes, and (iv) baseline weight, DR-TB centre and history of previous TB were significantly associated with unsuccessful treatment outcomes. Of all DR-TB patients registered, 16% were DR-EPTB cases. These figures are comparable to the prevalence of EP disease in drug-sensitive cases . This isLymph node involvement is the most common EPTB, in general. We encountered a similar pattern in the DR-EPTB cases in the previous literature from the Netherlands (39%), the United States (40%), and the United Kingdom (37%) ,22. PleuNearly two-thirds of DR-EPTB cases (66%) had favourable treatment outcomes. This is better than the outcomes of the overall national DR-TB cohort (47%) notified between the 3rd quarter of 2014 to the 2nd quarter of 2015, which ranged between 36%–61% across all states . SimilarA recent study at a DR-TB centre in Mumbai reported a much higher completion rate of 82% among DR-EPTB patients, probably because it was a single centre study with different patient profiles and the use of a shorter regimen, which showed much better treatment completion rates .A review found that the death rates among DR-EPTB patients were widely ranged from 0%–80% in different studies across the globe . This wiLTFU is common, which was seen among one-fifth of the patients. However, newer initiatives such as mobile adherence support, online web-based platform (Nikshay) for real-time reporting, efficient referral systems using Nikshay ID and newer treatment guidelines  could contribute to a decrease in LTFU.The risk factors for unfavourable treatment outcomes help in stratifying patients for additional monitoring and improving outcomes. Patients with a previous history of TB have worse outcomes, which supports the findings in other studies ,11. ThisPatients registered at DR-TB Centre 2 had a higher risk of unfavourable treatment outcomes, mostly LTFU or transferred out, because the centre receives a large number of patients from regions outside Delhi, who are eventually lost to follow-up. This calls for close monitoring, and better linkages and tracking of such patients.A weight band between 31–50 kg at baseline was found to be significantly associated with unfavourable treatment outcomes compared to a weight band of < 30 kg. This has to be interpreted with caution as the role of unexplained confounders cannot be ruled out. A stratified analysis was conducted to study the association of weight bands on treatment outcomes in different age groups (children < 15 years and adults > 15 years). Although statistical significance was not seen, the proportion of outcomes among the 31–50 kg weight band was higher compared to other weight bands. Statistical nonsignificance could be due to small numbers and fewer numbers of outcomes in exposure categories, especially among children. This warrants a better understanding of the role of initial weight in determining treatment outcomes. We also need to explore whether a change in weight during the course of treatment or body mass index are better indicators compared to baseline weight in predicting outcomes. The strength of this study is that it was conducted within the routine programmatic setting in three designated Nodal DR-TB centres under RNTCP in Delhi. All the cases of DR-EPTB registered during the study period from three out of four nodal DR TB centres (covering 21 out of 25 chest clinics) in Delhi were included in the study without any exclusion, which covered nearly 90% of all such cases during the study period. This lends generalizability to the study findings. The study also adhered to Strengthening the Reporting of Observational studies in Epidemiology (STROBE) guidelines for conducting and reporting on observational studies [The study results have four important programmatic implications. First, high rates of death and LTFU among DR-EPTB patients need to be addressed urgently. Besides the risk factors identified in this study, some of which are non-modifiable, a shorter and easier-to-follow DR-TB treatment regimen with newer oral drugs such as bedaquiline or delamanid is probably the answer to reducing mortality and LTFU in this patient group. With the recent evidence from trials and large observational cohorts, the WHO stance has also departed from conventional treatment approaches for MDR TB in favour of shorter regimens with noninjectables ,26,27. HSecond, low weight was also one of the risk factors for unfavourable treatment outcomes, which require tailored interventions to improve treatment outcomes for these patient sub-groups, especially those with poor weight at baseline and with a previous history of TB. The national program has initiated "Nikshay Poshan Yojana" which provides incentives for nutritional support to TB patients, which is a welcome step; however, studies have reported poor implementation of this . Proper Third, the proportion of DR EP-TB diagnosed clinically stands at a dismal 4% in this study. The diagnosed drug-sensitive EP-TB cases in Delhi constitute about 40%–45% of all TB cases, as per the India TB Report, while DR EP-TB is usually 15% to 20% of all DR-TB cases. It shows that we are probably missing clinically diagnosed EP-DRTB cases. Clinical nonresponders of EP-TB need to be reported too. In addition, there is over-reliance on bacteriological confirmation and drug sensitivity testing for the diagnosis of DR EP-TB, which is resulting in the underestimation of clinically diagnosed cases. Thus, diagnosis should be based on clinical judgement supported by culture/Xpert results, and not solely on bacteriological tests, as is common practice.Fourth, those with a previous history of TB could be followed-up for at least two years to document relapse-free survival. For this, an aggressive strategy of follow-up and monitoring needs to be in place.DR-EPTB constitutes a significant subgroup of the DR-TB cases that needs urgent attention. Every third DR-EPTB patient has unfavourable treatment outcomes, with high rates of LTFU that needs to be tackled if we are to realise the goal of ending TB. The use of shorter regimens and close monitoring/tracking of the migrant population and the transfer-out cases are required to minimise LTFU. Those with a previous history of TB need to be monitored closely for compliance to treatment. Further studies are needed to understand the operational reasons for the low proportion of clinically diagnosed DR EP-TB and explore the role of baseline weight or other proxy indicators, such as body mass index or weight gain during the treatment, in predicting treatment outcomes.


Undifferentiated carcinoma of the pancreas is an aggressive but rare tumor for which several other terms have been used to describe its histological appearance. In addition, as osteoclast-like giant cells may accompany undifferentiated carcinoma of the pancreas, the WHO Classification distinguishes undifferentiated carcinoma with osteoclast-like giant cells (UC-OGC) from plain undifferentiated carcinoma since there are a few histopathological and clinical differences. UC-OGC was initially thought to be associated with worse prognosis compared to invasive ductal pancreatic adenocarcinoma, since it is often unresectable at diagnosis and tends to recur rapidly even if completely resected. When true UC-OGGs are carefully dissected out from other anaplastic carcinomas, it becomes, however, clear that UC-OGCs do have more indolent behavior, especially the pure UC-OGCs. This mini-review summarizes the current knowledge on UC-OGC. Undifferentiated carcinoma of the pancreas is an aggressive but rare tumor for which several other terms have been used to describe its histological appearance: anaplastic carcinoma, pleomorphic carcinoma, pleomorphic large cell carcinoma, pleomorphic giant cell carcinoma, spindle cell carcinoma, sarcomatoid carcinoma and carcinosarcoma. In the current WHO Classification, all these terms are lumped together into one single category designated as undifferentiated carcinoma of the pancreas despite their histological differences . In addiUndifferentiated carcinoma of the pancreas is a rare tumor  and UC-OLiterature on UC-OGC is relatively scarce and largely based on case reports. In this review we mainly focus on the histological and molecular aspects of UC-OGC.Tumors with osteoclast-like giant cells have been reported within a variety of organs including the skin , breast th edition of WHO classification, UC-OGC contains three cell types: osteoclast-like multinucleated giant cells that are non-neoplastic, mononuclear histiocytes, and neoplastic mononuclear cells   . Interesserpins) . Moreoveserpins)  and SERPserpins) .GLI3 mutations in two cases suggests that GLI3 is also a driver of UC-OGC  formation and, finally, to invasive ductal adenocarcinoma  allowing recruitment of non-neoplastic OGCs , and higPancreatic ductal adenocarcinoma has been well described in terms of computed tomography (CT) and magnetic resonance imaging (MRI) characteristics. The CT and MRI characteristics of undifferentiated carcinoma of the pancreas are, however, not well known. On imaging work-up, UC-OGC appears larger than pancreatic ductal adenocarcinoma and generally displays a cystic component . Bile duElevated serum levels of CEA and CA19.9 are less commonly observed than in pancreatic ductal adenocarcinoma . EndoscoThe survival of UC-OGC varies from 4 months to 10 years . ShiozawLuchini et al. demonstrated that the most important criterium for prognosis is the presence of an associated pancreatic ductal adenocarcinoma; they showed that median overall survival for pure UC-OGC was 36 months, compared with 15 months for UC-OGC with associated pancreatic ductal adenocarcinoma . This stDue to the rarity of UC-OGC, treatment options have never been standardized. Surgery is the first-choice treatment. The efficacity of radio- and/or chemotherapy in UC-OGC remains to be evaluated ; since U+ and CD8+ tumor-infiltrating lymphocytes/mm2 than conventional pancreatic ductal adenocarcinoma (PD-1 or PD-L1 monoclonal antibody therapy has demonstrated promising therapeutic effects in clinical studies of several cancer types. This therapy has been succesful in multiple prospective randomized clinical trials on non-small cell lung cancer, renal cell carcinoma, melanoma, Hodgkin lymphoma, breast carcinoma, head and neck squamous cell carcinoma and a subset of urothelial carcinoma –72. It harcinoma . These iarcinoma .i.e. UC-OGC without associated ductal adenocarcinoma. The improved survival of patients with pure UC-OGC might suggest that the unique morphology is a result of the immune response to an otherwise classical ductal pancreatic adenocarcinoma: elimination of the pancreatic ductal adenocarcinoma component by a strong immune respons could result in improved prognosis (The identification of UC-OGC is important since this tumor has a better prognosis than conventional pancreatic ductal adenocarcinoma and than undifferentiated carcinoma without giant cells. This especially holds true for pure UC-OGC, rognosis . Proof fRecent studies have given important new insights into the clinical and molecular features of UC-OGC. Available data suggest that UC-OGC shares genetical similarities with conventional ductal adenocarcinoma, but is clinically distinct from it. Future studies should compare molecular alterations in UC-OGC and associated pancreatic ductal adenocarcinomas from the same patient to further define what is unique or typical for UC-OGC. The histopathological and clinical characteristics of this tumor type are, however, unlikely to be due to specific genetic alterations but are probably the result of gene expression or other molecular processes not related to somatic mutations .+ TAM2 that promote survival and proliferation of neoplastic cells (Currently surgery is the first-choice treatment whereas the efficacy of radio- and/or chemotherapy remains to be evaluated. Since expression of PD-L1 is associated with poor prognosis, a clinical trial with immune checkpoint immunotherapy seems warranted. Moreover, since the neoplastic cells and osteoclast-like giant cells are surrounded by CD163ic cells , UC-OGC ic cells , 77. WhoPD and LV contributed equally to this work, generated the figures, and wrote the manuscript. RM, FP, MD, SD, FC, MG, and JLVL contributed to the writing of the manuscript. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.