Comparative performance analysis of mussel-inspired polydopamine, polynorepinephrine, and poly-α-methyl norepinephrine in electrochemical biosensors.

Polydopamine (PDA) has garnered significant interest for applications in biosensors, drug delivery, and tissue engineering. However, similar polycatecholamines like polynorepinephrine (PNE) with additional hydroxyl groups and poly-α-methylnorepinephrine (PAMN) with additional hydroxyl and methyl groups remain unexplored in the biosensing domain. This research introduces three innovative biosensing platforms composed of ternary nanocomposite based on reduced graphene oxide (RGO), gold nanoparticles (Au NPs), and three sister polycatecholamine compounds (PDA, PNE, and PAMN). The study compares and evaluates the performance of the three biosensing systems for the ultrasensitive detection of Mycobacterium tuberculosis (MTB). The formation of the nanocomposites was meticulously examined through UV-Visible, Raman, XRD, and FT-IR studies with FE-SEM and HR-TEM analysis. Cyclic voltammetry and differential pulse voltammetry measurements were also performed to determine the electrochemical characteristics of the modified electrodes. Electrochemical biosensing experiments reveal that the RGO-PDA-Au, RGO-PNE-Au, and RGO-PAMN-Au-based biosensors detected target DNA up to a broad detection range of 0.1 × 10-8 to 0.1 × 10-18 M, with a low detection limit (LOD) of 0.1 × 10-18, 0.1 × 10-16, and 0.1 × 10-17 M, respectively. The bioelectrodes were proved to be highly selective with excellent sensitivities of 3.62 × 10-4 mA M-1 (PDA), 7.08 × 10-4 mA M-1 (PNE), and 6.03 × 10-4 mA M-1 (PAMN). This study pioneers the exploration of two novel mussel-inspired polycatecholamines in biosensors, opening avenues for functional nanocoatings that could drive further advancements in this field.

Bio-inspired polynorepinephrine based nanocoatings for reduced graphene oxide/gold nanoparticles composite for high-performance biosensing of Mycobacterium tuberculosis.

Polydopamine (PDA) has established itself as a promising grafting and coating material, particularly for functional group-deprived electrochemically active nanomaterials such as graphene, MXene, CNT, metal nanoparticles, and so on, and has proven its extensive applicability in the design and development of electrochemical biosensor devices. However, polynorepinephrine (PNE), a sister compound of PDA, having additional -OH groups and greater coating uniformity and biocompatibility, has never been studied in the field of biosensors. Herein, we investigated PNE as a coating material for reduced graphene oxide (RGO) and gold nanoparticles (Au) in order to build an electrochemical genosensor for Mycobacterium tuberculosis (MTB) detection. Biotin-Avidin chemistry was used to covalently immobilize probe DNA (ssDNA) specific to MTB to the nanocomposite surface on glassy carbon electrode (GCE) in order to construct biosensing electrodes. The formation of RGO/PNE and RGO/PNE/Au nanocomposite as well as the immobilization of ssDNA onto the bioelectrodes are both corroborated by UV-Visible, Raman, and XRD studies with FE-SEM and HR-TEM analysis. The electrochemical studies performed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) showed the significant enhancement in charge transfer kinetics of RGO/PNE/GCE and RGO/PNE/Au/GCE electrode compared to GO/GCE electrode. The biosensing investigations performed using ssDNA/avidin/RGO/PNE/Au/GCE bioelectrode showed high sensitivity (2.3 × 10-3 mA µM-1), low detection limit (0.1 × 10-7 µM), broad detection range (0.1 × 10-2 to 0.1 × 10-7 µM) with good selectivity and low response time (5 s) of the developed sensor. In comparison to the analogous RGO/PDA/Au material system, RGO/PNE/Au demonstrated increased enzyme loading, improved electrochemical responsiveness, and superior biosensing performance.

Ternary nanocomposite-based smart sensor: Reduced graphene oxide/polydopamine/alanine nanocomposite for simultaneous electrochemical detection of Cd2+, Pb2+, Fe2+, and Cu2+ ions.

Heavy metal ion (HMI) sensors are the most sought commercial devices for environmental monitoring and food analysis research due to serious health concerns associated with HMI overdosage. Herein, we developed an effective electrochemical sensor for simultaneous detection of four HMI (Cd2+, Pb2+, Fe2+, and Cu2+) using a ternary nanocomposite of reduced graphene oxide functionalized with polydopamine and alanine (ALA/pDA/rGO). Comprehensive spectroscopic and microscopic characterizations were performed to ensure the formation of the ternary nanocomposite. The developed nanocomposite on glassy carbon electrode (GCE) yields >2-fold higher current than GO/GCE electrode with excellent electrochemical stability and charge transfer rate. Using DPV, various chemical and electrochemical parameters, such as supporting electrolyte, buffer pH, metal deposition time, and potential, were optimized to achieve highly sensitive detection of targeted HMI. For Cd2+, Pb2+, Fe2+, and Cu2+ sensing devised sensor exhibited detection limits of 1.46, 2.86, 50.23, and 17.95 ppb and sensitivity of 0.0929, 0.0744, 0.0051, and 0.0394 µA/ppb, respectively, with <6% interference. The sensor worked similarly well for real water samples with HMI. This study demonstrates a novel strategy for concurrently detecting and quantifying multiple HMI in water and soil using a smart ternary nanocomposite-based electrochemical sensor, which can also detect HMI in food samples.

Diversity of Vibrio parahaemolyticus in marine fishes of Bangladesh.

AIMS: To determine the occurrence, diversity, antibiotic resistance and biofilm formation of Vibrio parahaemolyticus isolated from marine fishes in Bangladesh. METHODS AND RESULTS: A total of 80 marine fishes were obtained from the local markets and examined for the presence of V. parahaemolyticus. All the isolated V. parahaemolyticus were characterized for the presence of virulence markers, thermostable direct hemolysin (TDH) or thermostable direct hemolysin related hemolysin (TRH). Isolates were serotyped and further characterized by enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) typing to analyse the genetic diversity. Moreover, biofilm formation and antibiotic resistance patterns were also determined. About 63·75% (51/80) of the tested marine fishes were contaminated with V. parahaemolyticus. From the contaminated fishes, 71 representatives V. parahaemolyticus were isolated and none of them harboured tdh and trh virulence genes. Nine different O-groups and seven different K-types were found by serological analysis and the dominant serotype was O5:KUT. In ERIC-PCR analysis, eight clusters (A-H) were found and the most common pattern was A (46·5%). All of the isolates were resistant to ampicillin and 78·9% of isolates were resistant to streptomycin. The highest biofilm formation was found at 37°C compared to 25°C and 4°C. CONCLUSION: Diverse V. parahaemolyticus are present in marine fishes in the local market of Bangladesh with antibiotic-resistant properties and biofilm formation capacity. SIGNIFICANCE AND IMPACT OF THE STUDY: The widespread prevalence of diverse V. parahaemolyticus in marine fishes is an issue of serious concern, and it entails careful monitoring to ascertain the safety of seafood consumers.

Current Trends of Using Antimicrobials at Obstetrics and Gynaecology Department in a Tertiary Care Hospital.

This cross-sectional descriptive study was done to analyse the current trends of using antimicrobials in various surgical procedures at Obstetrics and Gynaecology department in Mymensingh Medical College Hospital, Mymensingh from July 2014 to June 2015. Among 300 postoperative obstetrics and gynaecological surgery cases, samples were selected as non-random purposive selection method where pattern of using antimicrobials were analysed by SPSS method 20.1 versions. The incidence of antimicrobial resistance is on continued rise with a threat to return to the pre-antibiotic era. This has led to emergence of such bacterial infections which are essentially untreatable by the current armamentarium of available treatment options. Now-a-days variation of choosing antibiotic are quietly accepted in Obstetrics and Gynaecology department as prophylaxis purpose to control life threatening conditions such as postoperative wound infection, septicaemia, urinary tract infection etc. The data analysis revealed that among 300 obstetrical and gynaecological surgeries, Nitroimidazoles (93.33%), Cephalosporins (91%) and Aminoglycosides (59%) group were most commonly used antimicrobials in both obstetrics and gynaecological surgeries. Metronidazole (93.33%), Ceftriaxone (68.66%), Gentamicin (60.33%), Cefuroxime (48%), Flucloxacillin (42%), Cefixime (27%) were the most commonly used antimicrobials at obstetrics and gynaecology department. Combination of Ceftriaxone, Metronidazole and Gentamicin (37.66%), Ceftriaxone and Metronidazole (25.33%), Cefuroxime, Metronidazole and Gentamicin (16%), Ciprofloxacin, Metronidazole and Gentamicin (5.33%) were most commonly used antimicrobials postoperatively. Total mean duration of antimicrobial therapy was 10.45 days. Antibiotics are useful in prevention of infection. But indiscriminately use of antibiotics without any guideline may lead to antimicrobial resistance. So, antimicrobial surveillance committee should be formed by hospital authority to know the local using pattern of antibiotics.

Outcome of Pregnancy Related Acute Kidney Injury Observed in a Tertiary Care Hospital.

This prospective case control study was carried out in Mymensingh Medical College Hospital (MMCH) from April 2011 to March 2012. The main objective of the study was to determine the short term maternal outcome of pregnancy related Acute Kidney Injury and to identify aetiological factors and to observe clinical features of pregnancy related Acute Kidney Injury. Total 60 pregnant women with AKI were included in the study as sample and equal (60) number of pregnant women with normal renal function was taken as control. Mean ages (±SD) of study and control group were observed 31.6±6.9 years and 25.5±4.7 years respectively. It was observed that most patients were from rural area with low income group. Most women were multiparous and presented in third trimester and postpartum period. Majority of the study subjects did not receive antenatal care at any stage of pregnancy. Fifty (86.7%) of the study subjects were oligo-anuric, forty-nine (81.7%) were edematous and fifty one (85%) were anaemic. Twenty-five (41.7%) patients presented with abnormal vaginal bleeding. Sepsis (including septic abortion and puerperal sepsis) was responsible for of Pregnancy Related AKI (PR-AKI) in more than two fifths of cases. Haemorrhage (APH & PPH combined) was the next common cause of Pregnancy Related AKI (PR-AKI). Toxemia of Pregnancy was responsible in one fourth of cases. Dialysis (HD & IPD combined) was required for two fifths of the patients. Rest patients were treated conservatively with antibiotics, blood transfusion, maintenance of fluid and electrolytes balance etc. Maternal outcome of Pregnancy related acute kidney injury was considered for the period of patient's hospital staying. 56.6% patients recovered completely, 15.0% patients recovered partially, 6.7% did not recover at the time of hospital discharge; while 21.7% died. So it can be concluded that, pregnancy related acute kidney injury is a critical condition, associated with worse prognosis.

Association of vitamin D status with incidence of enterotoxigenic, enteropathogenic and enteroaggregative Escherichia coli diarrhoea in children of urban Bangladesh.

OBJECTIVE: To evaluate the association between vitamin D status and diarrhoeal episodes by enterotoxigenic (ETEC), enteropathogenic (EPEC) and enteroaggregative (EAEC) E. coli in underweight and normal-weight children aged 6-24 months in urban Bangladesh. METHODS: Cohorts of 446 normal-weight and 466 underweight children were tested separately for ETEC, EPEC and EAEC from diarrhoeal stool samples collected during 5 months of follow-up while considering vitamin D status at enrolment as the exposure. Cox proportional hazards models with unordered failure events of the same type were used to determine diarrhoeal risk factors after adjusting for sociodemographic and concurrent micronutrient status. RESULTS: Vitamin D status was not independently associated with the risk of incidence of ETEC, EPEC and EAEC diarrhoea in underweight children, but moderate-to-severe retinol deficiency was associated with reduced risk for EPEC diarrhoea upon adjustment. Among normal-weight children, insufficient vitamin D status and moderate-to-severe retinol deficiency were independently associated with 44% and 38% reduced risk of incidence of EAEC diarrhoea, respectively. These children were at higher risk of ETEC diarrhoea with vitamin D deficiency status when adjusted for micronutrient status only. CONCLUSION: This study demonstrates for the first time that normal-weight children with insufficient vitamin D status have a reduced risk of EAEC diarrhoea than children with sufficient status. Moderate-to-severe deficiency of serum retinol is associated with reduced risk of EPEC and EAEC diarrhoea in underweight and normal-weight children.

Association between serum vitamin D, retinol and zinc status, and acute respiratory infections in underweight and normal-weight children aged 6-24 months living in an urban slum in Bangladesh.

We conducted a longitudinal assessment in 466 underweight and 446 normal-weight children aged 6-24 months living in the urban slum of Dhaka, Bangladesh to determine the association between vitamin D and other micronutrient status with upper respiratory tract infection (URI) and acute lower respiratory infection (ALRI). Incidence rate ratios of URI and ALRI were estimated using multivariable generalized estimating equations. Our results indicate that underweight children with insufficient and deficient vitamin D status were associated with 20% and 23-25% reduced risk of URI, respectively, compared to children with sufficient status. Underweight children, those with serum retinol deficiency were at 1·8 [95% confidence interval (CI) 1·4-2·4] times higher risk of ALRI than those with retinol sufficiency. In normal-weight children there were no significant differences between different vitamin D status and the incidence of URI and ALRI. However, normal-weight children with zinc insufficiency and those that were serum retinol deficient had 1·2 (95% CI 1·0-1·5) times higher risk of URI and 1·9 (95% CI 1·4-2·6) times higher risk of ALRI, respectively. Thus, our results should encourage efforts to increase the intake of retinol-enriched food or supplementation in this population. However, the mechanisms through which vitamin D exerts beneficial effects on the incidence of childhood respiratory tract infection still needs further research.

Intraductal papillary neoplasm of the bile duct (IPN-B): also a disease of western Caucasian patients. A literature review and case series.

Cholangiocarcinoma (CCa) is an aggressive malignancy, which often presents with advanced, inoperable disease. Early detection of any premalignant condition could improve the dismal prognosis of cholangiocarcinoma (5% 5-year survival). There are two premalignant precursors of CCa: biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct (IPN-B). BilIN is only visible microscopically; imaging has no role in identification. IPN-B is a recent diagnostic entity, arising from a World Health Organization (WHO) reclassification of tumours. IPN-B is visible macroscopically, and can be identified on imaging. With its propensity to spread preferentially along the biliary epithelium, only infiltrating the duct wall at a late stage, it may be more amenable to complete resection than typical CCa. The lead time with early detection, during which dysplasia could progress to invasive carcinoma, is an opportunity where resection may be curative. The literature on IPN-B has originated from Asia, but awareness of this condition in the western world is limited. We report a case series of IPN-B occurring in Caucasian patients from the UK, with radiological-pathological correlation. The protean imaging appearances present a unique challenge, but also a great opportunity, for radiologists. Early identification and resection of lesions, even in asymptomatic or minimally symptomatic patients, should be considered.

VULNERABILITY OF LOW-ARSENIC AQUIFERS TO MUNICIPAL PUMPING IN BANGLADESH.

Sandy aquifers deposited >12,000 years ago, some as shallow as 30 m, have provided a reliable supply of low-arsenic (As) drinking water in rural Bangladesh. This study concerns the potential risk of contaminating these aquifers in areas surrounding the city of Dhaka where hydraulic heads in aquifers >150 m deep have dropped by 70 m in a few decades due to municipal pumping. Water levels measured continuously from 2012 to 2014 in 12 deep (>150m), 3 intermediate (90-150 m) and 6 shallow (<90 m) community wells, 1 shallow private well, and 1 river piezometer show that the resulting drawdown cone extends 15-35 km east of Dhaka. Water levels in 4 low-As community wells within the 62-147 m depth range closest to Dhaka were inaccessible by suction for up to a third of the year. Lateral hydraulic gradients in the deep aquifer system ranged from 1.7×10-4 to 3.7×10-4 indicating flow towards Dhaka throughout 2012-2014. Vertical recharge on the edge of the drawdown cone was estimated at 0.21±0.06 m/yr. The data suggest that continued municipal pumping in Dhaka could eventually contaminate some relatively shallow community wells.

Inferring the fluoride hydrogeochemistry and effect of consuming fluoride-contaminated drinking water on human health in some endemic areas of Birbhum district, West Bengal.

This research work is carried out to evaluate fluoride (F) hydrogeochemistry and its effect on the population of two endemic villages of Birbhum district, West Bengal. Fluoride concentration in drinking water varies from 0.33 to 18.08 mg/L. Hydrogeochemical evolution suggests that ion-exchange mechanism is the major controlling factor for releasing F in the groundwater. Most of the groundwater samples are undersaturated with respect to calcite and fluorite. Health survey shows that out of 235 people, 142 people suffer from dental fluorosis. According to fluoride impact severity, almost 80 and 94 % people in an age group of 11-20 and 41-50 suffer from dental and skeletal fluorosis, respectively. Statistically drinking water F has a positive correlation with dental and skeletal fluorosis. Bone mineral density test reveals that 33 and 45 % of the studied population suffer from osteopenic and osteoporosis disease. IQ test also signifies that F has a bearing on the intelligence development of the study area school children. The existence of significant linear relationship (R (2) = 0.77) between drinking water F and urinary F suggests that consumption of F-contaminated drinking water has a major control over urinary F (0.39-20.1 mg/L) excretion.

Specific antibody responses as indicators of treatment efficacy for visceral leishmaniasis.

Acute visceral leishmaniasis (VL) is caused by infection with parasites of the Leishmania donovani complex and may be fatal if not treated. Early diagnosis and efficacious treatment are the keys to effective VL management and control. Novel regimens are being developed to overcome limitations in VL treatment options, which are currently restricted by high costs, severe systemic side effects, and unresponsiveness. Although simple and accurate serological tests are available to help confirm VL, none are suitable to monitor treatment efficacy and cure. Here, we confirm that serum antibody responses to the diagnostic antigens rK39 and rK28 are unaltered by treatment, but demonstrate that antibodies produced against two antigens, rK26 and rK18, can be used as an indirect measure of parasite clearance. The levels of anti-rK18 and -rK26 antibodies were high in patients at initial diagnosis but declined in patients treated with either SSG (Ethiopia) or AmBisome (Bangladesh). Taken together, we propose that serological tests which measure antibodies to rK26 and rK18 merit consideration as potential markers of treatment success and cure.

Nanofiltration based water reclamation from tannery effluent following coagulation pretreatment.

Coagulation-nanofiltration based integrated treatment scheme was employed in the present study to maximize the removal of toxic Cr(VI) species from tannery effluents. The coagulation pretreatment step using aluminium sulphate hexadecahydrate (alum) was optimized by response surface methodology (RSM). A nanofiltration unit was integrated with this coagulation pre-treatment unit and the resulting flux decline and permeate quality were investigated. Herein, the coagulation was conducted under response surface-optimized operating conditions. The hybrid process demonstrated high chromium(VI) removal efficiency over 98%. Besides, fouling of two of the tested nanofiltration membranes (NF1 and NF3) was relatively mitigated after feed pretreatment. Nanofiltration permeation fluxes as high as 80-100L/m(2)h were thereby obtained. The resulting permeate stream quality post nanofiltration (NF3) was found to be suitable for effective reuse in tanneries, keeping the Cr(VI) concentration (0.13mg/L), Biochemical Oxygen Demand (BOD) (65mg/L), Chemical Oxygen Demand (COD) (142mg/L), Total Dissolved Solids (TDS) (108mg/L), Total Solids (TS) (86mg/L) and conductivity levels (14mho/cm) in perspective. The process water reclaiming ability of nanofiltration was thereby substantiated and the effectiveness of the proposed hybrid system was thus affirmed.

Alteration of the serum biomarker profiles of visceral leishmaniasis during treatment.

Until recently, chemotherapy for visceral leishmaniasis (VL; also known as kala-azar) was severely limited by factors such as high cost, route of administration, generation of side effects and potential for resistance. Although largely effective, chemotherapies have become available with the introduction of new drugs and multi-drug regimens for VL. These could be further improved by the identification of biomarkers that are altered during effective treatment. The identification of such biomarkers in the circulation would also simplify efficacy trials. In this study, we determined immunological signatures within the serum of ethnically and geographically distinct VL patients (from Bangladesh and Brazil). Our results indicate that inflammatory and regulatory cytokines (IFNγ, TNFα, IL-10, IL-17), as well as levels of growth factors (FGF, VEGF), are elevated within the serum of VL patients from these sites. The examination of samples from Brazilian VL patients during and beyond standard treatment with meglumine antimoniate identified multiple parameters that revert to levels comparable to those of healthy endemic control individuals. The consolidation of these results provides a 'response to treatment' signature that could be used within efficacy trials to rapidly and simply determine successful interruption of VL.

How useful is endorectal ultrasound in the management of early rectal carcinoma?

INTRODUCTION: Endorectal ultrasonography (EUS) is used to T stage early rectal tumours and select patients to whom transanal endoscopic microsurgery (TEM) could be offered. Published papers have shown that EUS can have good accuracy, but there is little literature on how EUS influences patient management. The study aim is to ascertain the value of EUS in the management of early rectal tumours. METHODS: Patients with adenomas/early rectal carcinoma being considered for TEM were prospectively studied. Each patient underwent EUS. The surgeon recorded the expected T stage, confidence level of the T stage and management plan for each patient on a proforma before and after the ultrasound result was revealed. Comparison was made between the ultrasound stage and final pathological stage where available. RESULTS: Ninety-six patients were referred over 2 years. Nine were out of reach of the rigid probe and were excluded. Proformas were completed on 53/87 patients (age range 28-87 years, mean age 66 years, 30 males/23 females). Forty-eight patients had a pathological report to compare with the EUS T stage. Ultrasound agreed with the pathological T staging in 43 patients (90%). Patient management was changed in five patients. In 30% of (16/53) patients, EUS increased the confidence level for T staging. CONCLUSION: Although EUS has a high accuracy in predicting the T stage of early rectal cancers, it never changes the management plan for lesions thought to be benign. It seldom changes the pre-operative selection process when clinical examination is considered with other imaging modalities (MRI/CT). EUS should be reserved for answering specific questions in difficult cases rather than for all patients.

A thermo-mechanically loaded rotating FGM cylindrical pressure vessels under parabolic changing properties: An analytical and numerical analysis.

This study aims to develop an exact analytical solution for steady-state thermo-mechanical stress in a functionally graded (FG) thick-walled cylindrical vessel. The cylinder is subjected to combined rotational speed and internal pressures while the thermal load is with convective and radiative boundary conditions. The dimensionless governing equations and boundary conditions, represented as a quartic equation, are derived and solved using Ferrari's method. The temperature, displacement, and stress fields across the thick-walled cylindrical vessel are calculated by finding the roots of the quartic equation. In order to investigate the accuracy of the exact analytical solution, a numerical model is constructed based on a standard Galerkin discretization approach of the finite element method (FEM). The analytical solutions and the results obtained through FEM show a high level of agreement. Furthermore, the study analyzes the effects of material parameters on temperature, displacement, and stress fields. Displacement, temperature, and stress fields are presented in the form of dimensionless graphs along the radial direction. For the considered parametric studies, results revealed that parabolic grading is beneficial than conventional grading. This study reveals that for the thermal loading, the maximum temperature, displacement, and tangential stress decrease for the parabolic grading. A similar but lower value of temperature, displacement, and tangential stress is also observed in the case of thermomechanical loading. This study is expected to assist in the assessment of the reliability of load calculations and contribute to the overall durability of pressure vessels. The results obtained from this study can provide valuable insights into thermo-elasticity and the thermo-mechanical behavior of thick-walled cylindrical vessels and can aid in the design and optimization of such systems.

An insight to the recent advancements in detection of Mycobacterium tuberculosis using biosensors: A systematic review.

Since ancient times, Tuberculosis (TB) has been a severe invasive illness that has been prevalent for thousands of years and is also known as "consumption" or phthisis. TB is the most common chronic lung bacterial illness in the world, killing over 2 million people each year, caused by Mycobacterium tuberculosis (MTB). As per the reports of WHO, in spite of technology advancements, the average rate of decline in global TB infections from 2000-2018 was only 1.6% per year, and the worldwide reduction in TB deaths was only 11%. In addition, COVID-19 pandemic has reversed years of global progress in tackling TB with fewer diagnosed cases. The majority of undiagnosed patients of TB are found in low- and middle-income countries where the GeneXpert MTB/RIF assay and sputum smear microscopy have been approved by the WHO as reference procedures for quickly detecting TB. Biosensors, like other cutting-edge technologies, have piqued researchers' interest since they offer a quick and accurate way to identify MTB. Modern integrated technologies allow for the rapid, low-cost, and highly precise detection of analytes in extremely little amounts of sample by biosensors. Here in this review, we outlined the severity of tuberculosis (TB) and the most recent developments in the biosensors sector, as well as their various kinds and benefits for TB detection. The review also emphasizes how widespread TB is and how it needs accurate diagnosis and effective treatment.

Human resource assessment for scaling up VL active case detection in Bangladesh, India and Nepal.

OBJECTIVES: To determine whether medical staff at PHC level would have the time to take up additional activities such as 1-day fever camps for active VL case detection. METHODS: This article assessed the workload of health staff of different professional categories working at health facilities in Bangladesh, India and Nepal. Data were collected from different sites in high endemic VL areas. The study population was the health staff of government health facilities at all levels. Workload indicators of staffing need (WISN) software were adopted to carry out the analysis of staff workload and their availability in the selected health facility. The WISN difference and WISN ratio for a particular health facility were calculated from actual staffing available and calculated staffing requirement. RESULTS: The results showed a mixed picture of the availability of health workers. In most settings of Bangladesh and India, physicians with or without laboratory technicians would have time for active case detection. In Nepal, this would be performed by trained nurses and paramedical personnel. CONCLUSION: If all vacant posts were filled, active case detection could be performed more easily. The elimination programme can be scaled up with the current staffing levels in the endemic areas with some short training if and when necessary.

Exact goodness-of-fit tests for Markov chains.

Goodness-of-fit tests are useful in assessing whether a statistical model is consistent with available data. However, the usual χ² asymptotics often fail, either because of the paucity of the data or because a nonstandard test statistic is of interest. In this article, we describe exact goodness-of-fit tests for first- and higher order Markov chains, with particular attention given to time-reversible ones. The tests are obtained by conditioning on the sufficient statistics for the transition probabilities and are implemented by simple Monte Carlo sampling or by Markov chain Monte Carlo. They apply both to single and to multiple sequences and allow a free choice of test statistic. Three examples are given. The first concerns multiple sequences of dry and wet January days for the years 1948-1983 at Snoqualmie Falls, Washington State, and suggests that standard analysis may be misleading. The second one is for a four-state DNA sequence and lends support to the original conclusion that a second-order Markov chain provides an adequate fit to the data. The last one is six-state atomistic data arising in molecular conformational dynamics simulation of solvated alanine dipeptide and points to strong evidence against a first-order reversible Markov chain at 6 picosecond time steps.

Reduced Graphene Oxide-Polydopamine-Gold Nanoparticles: A Ternary Nanocomposite-Based Electrochemical Genosensor for Rapid and Early Mycobacterium tuberculosis Detection.

Tuberculosis (TB) has been a devastating human illness for thousands of years. According to the WHO, around 10.4 million new cases of tuberculosis are identified every year, with 1.8 million deaths. To reduce these statistics and the mortality rate, an early and accurate TB diagnosis is essential. This study offers a highly sensitive and selective electrochemical biosensor for Mycobacterium tuberculosis (MTB) detection based on a ternary nanocomposite of reduced graphene oxide, polydopamine, and gold nanoparticles (rGO-PDA-AuNP). Avidin-biotin coupling was used to bind the MTB probe DNA onto the rGO-PDA-AuNP modified glassy carbon electrode (ssDNA/avidin/rGO-PDA-AuNP). UV-Visible, Raman, XRD, and TEM were used to evaluate the structural and morphological characteristics of rGO-PDA-AuNP. Furthermore, DNA immobilization is validated using FESEM and FT-IR techniques. The modified electrodes were electrochemically analyzed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV), and the results indicate that the produced electrode can detect target DNA up to 0.1 × 10-7 mM with 2.12 × 10-3 mA µM-1 sensitivity and a response time of 5 s. The constructed genosensor displayed high sensitivity and stability, and it also provides a unique strategy for diagnosing MTB at an early stage. Furthermore, our rGO-PDA-AuNP/GCE-based electrochemical platform has broad potential for creating biosensor systems for detecting various infectious pathogens and therapeutically significant biomarkers.