Search

Usually, external solutes alter the local structural arrangement of the water hydrogen bond (H-bond) network. However, urea has a negligible effect on the local structure of water, irrespective of its concentration. In this work, we aim to find the microscopic origin of the inertness of urea toward water’s local structure by using theoretical isotope dilute IR spectroscopy. To get a microscopic resolution of different local environments, we investigate frequency distributions, population of structurally different ensembles, H-bond configurations, and H-bond strength. We find that urea has a negligible effect on the vibrational spectroscopic signatures of water. The solvation shell-wise decomposition of frequency distribution further reveals that the urea has almost zero perturbation to the local structure of any of its solvation shells. However, the frequency distribution of waters near the C=O group and NH2 group reveals a non-negligible impact by urea on water. The frequency distribution of the CO-region is red-shifted and narrower than the bulk water response, indicating a stronger H-bond and enhanced structural ordering of the waters in the CO-region; however, an opposite response is observed for the NH-region. The H-bond strength outcome further supplements this finding. We infer that the O-H oscillators in the CO-region and NH-region have non-negligible counteracting perturbation from the urea molecule. Yet, the overall response is free from any such effects. The insignificant populations and counteracting responses of these two ensembles play a major role.

Abstract Current study examined the magnetohydrodynamic (MHD) Prandtl nanofluid of a thermal double‐diffusive flow through an exponentially vertical surface in association with heat generation, and thermophoresis effect. The novelty of this study is due to the analysis of Prandtl nanofluid model with Soret mechanism and chemically responding fluids. This suggested model is beneficial since it can significantly advance the domains of thermal and industrial engineering. The fluid flow phenomenon is characterized by nonlinear coupled differential equations involving two or more independent variables. A suitable numerical technique is used to handle the set of governing equations along with a stability and convergence analysis. According to recent study, the fluid velocity increases since all the parameters are set to higher levels. For the various parametric values, isotherms and streamlines have been explored. This suggested model is beneficial since it can significantly advance the domains of thermal and industrial engineering. For instance, thermal radiation is crucial in designing sophisticated energy‐transformed systems that operate at high temperatures. On the other hand, the phenomenon of Soret is useful in separating isotopes in chemical engineering. An important findings of the current investigations can be treated as, radiative heat encourages fluid temperature distribution since it is the measure of the electromagnetic element radiates from the fluid particle that convert it into thermal radiation. These studies have several applications in the manufacturing and biomedical fields, petrochemical industries, automobiles, medical sciences, and various production processes in industries.

The Indo-Burma area is one of the most seismically active regions because of subduction of the Indian plate under the Burmese plate. The Indo-Burma area, which is bordered by 22°–27°N and 92°–97°E, has of late witnessed multiple moderate-to-large earthquakes. Seismic hazard assessment has been performed using the well-known extreme value theory, including estimate of return periods and likelihood of occurrence of medium to large earthquake events. The Indo-Burma region's seismic hazard parameterization has been computed using a homogeneous and thorough earthquake database created for the time span between 1973 and 2021. Due to an insufficient dataset, the b-value calculated using the GR relation was determined to be unsatisfactory (0.58). Therefore, the b-value was estimated using Gumbel's extreme value approach (0.902). The findings show that earthquake of 5.352 magnitude is likely to be the greatest annual earthquake in the study area. Additionally, the most likely large earthquakes that might happen throughout a wide range of periods have been projected and displayed.

In today’s fast-paced world, people increasingly rely on a variety of processed foods due to their busy lifestyles. The enhanced flavors, vibrant colors, and ease of accessibility at reasonable prices have made ready-to-eat foods the easiest and simplest choice to satiate hunger, especially those that undergo thermal processing. However, these foods often contain an unsaturated amide called ‘Acrylamide’, known by its chemical name 2-propenamide, which is a contaminant formed when a carbohydrate- or protein-rich food product is thermally processed at more than 120 °C through methods like frying, baking, or roasting. Consuming foods with elevated levels of acrylamide can induce harmful toxicity such as neurotoxicity, hepatoxicity, cardiovascular toxicity, reproductive toxicity, and prenatal and postnatal toxicity. This review delves into the major pathways and factors influencing acrylamide formation in food, discusses its adverse effects on human health, and explores recent techniques for the detection and mitigation of acrylamide in food. This review could be of interest to a wide audience in the food industry that manufactures processed foods. A multi-faceted strategy is necessary to identify and resolve the factors responsible for the browning of food, ensure safety standards, and preserve essential food quality traits.

Light-intensity-modulated displacement sensors are extensively used in numerous applications. Such type of sensors operates by utilizing a pair of adjacent optical fiber—one as transmitter and the other one as receiver. Such displacement sensors have the benefits of higher sensitivity and operating range, because they can efficiently collect more light after a reflectance has occurred. In this brief communication, we report all fiber optic displacement sensor using different reflectors such as plane, convex and concave. The experiment has been performed in the context of different refractive index-based solutions along with a comparative sensing analysis of these sensors. The attained results indicate that concave reflector-based displacement sensor yields the maximum sensitivity as compared to the other reflectors. Further, there has been good corroboration between simulated and observed transmittance. The findings is envisioned to help build more inexpensive displacement sensors with augmented sensitivity.

ABSTRACT Estimates of incidence based on medically attended cholera can be severely biased. Vibrio cholerae O1 leaves a lasting antibody signal and recent advances showed that these can be used to estimate infection incidence rates from cross-sectional serologic data. Current laboratory methods are resource intensive and challenging to standardize across laboratories. A multiplex bead assay (MBA) could efficiently expand the breadth of measured antibody responses and improve seroincidence accuracy. We tested 305 serum samples from confirmed cholera cases (4 to 1083 d postinfection) and uninfected contacts in Bangladesh using an MBA (IgG/IgA/IgM for 7 Vibrio cholerae O1-specific antigens) as well as traditional vibriocidal and enzyme-linked immunosorbent assays (2 antigens, IgG, and IgA). While postinfection vibriocidal responses were larger than other markers, several MBA-measured antibodies demonstrated robust responses with similar half-lives. Random forest models combining all MBA antibody measures allowed for accurate identification of recent cholera infections (e.g., past 200 days) including a cross-validated area under the curve (cvAUC200) of 92%, with simpler 3 IgG antibody models having similar accuracy. Across infection windows between 45 and 300 days, the accuracy of models trained on MBA measurements was non-inferior to models based on traditional assays. Our results illustrated a scalable cholera serosurveillance tool that can be incorporated into multipathogen serosurveillance platforms. IMPORTANCE Reliable estimates of cholera incidence are challenged by poor clinical surveillance and health-seeking behavior biases. We showed that cross-sectional serologic profiles measured with a high-throughput multiplex bead assay can lead to accurate identification of those infected with pandemic Vibrio cholerae O1, thus allowing for estimates of seroincidence. This provides a new avenue for understanding the epidemiology of cholera, identifying priority areas for cholera prevention/control investments, and tracking progress in the global fight against this ancient disease.

BackgroundImmune responses that target sialidase occur following natural cholera and have been associated with protection against cholera. Sialidase is a neuraminidase that facilitates the binding of cholera toxin (CT) to intestinal epithelial cells. Despite this, little is known about age-related sialidase-specific immune responses and the impact of nutritional status and co-infection on sialidase-specific immunity.MethodsWe enrolled 50 culture-confirmed Vibrio cholerae O1 cholera cases presenting to the icddr,b Dhaka hospital with moderate to severe dehydration. We evaluated antibody responses out to 18 months (day 540) following cholera. We assessed immune responses targeting sialidase, lipopolysaccharide (LPS), cholera toxin B subunit (CtxB), and vibriocidal responses. We also explored the association of sialidase-specific immune responses to nutritional parameters and parasitic co-infection of cases.ResultsThis longitudinal cohort study showed age-dependent differences in anti-sialidase immune response after natural cholera infection. Adult patients developed plasma anti-sialidase IgA and IgG responses after acute infection (P

Background: Lung disease is viewed as perhaps the most far reaching and deadly malignancies all throughout the planet. The most seasoned and most crucial technique is based on sputum cytology. The last outskirts for getting sufficient material are fine needle yearning cytology (FNAC) of bronchial development. Aims and Objective: To relate the meaning of sputum cytology and fine needle goal cytology of bronchial tissue under CT rules for diagnosing cellular breakdown in the lungs. Materials and Methods: This potential observational investigation was completed by the division of medication in Chattogram Medical College Hospital, Chattogram, Bangladesh. Where data was collected from January 2019 to June 2020. A total of 50 patients with a suspected history, symptoms, and risk profile of having primary lung cancer, as demonstrated by chest radiography and CT scan, were chosen for the research population. Fifty patients with clinical and biochemical verification of suspected. All collected data were coding and input in SPSS-25 for further analysis. Both descriptive and inferential statistics were tested. Results: Among the 50 patients the vast majority of the patients were 51-60 years of age and the biggest number of the (94 %) patients were male. Sputum cytology is 8% touchy which isn’t steady with different examinations and CT guided FNAC is 94% sensitive. Conclusion: A definitive point of picture guided histological or cytological examination is to stay away from unnecessary thoracotomy and accomplish a particular determination with sensible exactness and least results. So, in this examination we found that sputum cytology is 8% delicate which isn’t steady with different investigations and CT guided FNAC is 94% touchy to last histological analysis of lung cancer. The discoveries recommended that CT guided FNAC discovered to be protected, feasible and viable.

This short communication reports a unique proposition of a versatile sensing scheme—aimed at early detection of oral cancer. Based on intensity modulation, the probe can render both qualitative as well as quantitative assessments via saliva samples. It can further plausibly affirm the stage of oral cancer in the patient. With remarkable response time and superior specificity due to incorporation of biomarkers, this catheter like probe allows user to get rid of sample storage problem and other allied complications.

This paper presents the fabrication of a prototype with unique functionalities for monitoring human heart rate via simple insertion of fingertip on an infrared based sensor. The variation in the absorbance caused by the repeated pumping of oxygenated blood to various tissues within the body leads to distinct peaks and dips corresponding to the signal from the detector. Further, a MATLAB based Graphical User Interface (GUI) is developed to visualize this heart-beat signal as well as count the heart rate. In addition, the oxygen concentration can also be deciphered from the reported sensing scheme. The developed prototype seems to be in excellent match with standard heartrate monitoring device. It is believed that this multimodal prototype will pave way for more investigation towards development of sophisticated AI based analysis.

With the persistent rise of COVID-19 cases, it is imperative to have rapid assessment of infection with minimal logistics. Although different diagnostic techniques for SRAS-CoV-2 are available, there are limitations in terms of turn-around time, sensitivity, and specificity issues. In this direction, this work reports the effective exploitation of fiber optic biosensor especially for in vivo identification of SARS-CoV-2. The proposed catheter like probe is envisioned to alleviate the need for sample storage as well as other allied complicacies. The scheme for qualitative as well as quantitative assessment is elaborately presented here for this portable probe. The proposed probe equipped with rapid diagnosis is believed to have immense potential through adaptive measures.

Cancer is one of the dreaded diseases to which a sizeable proportion of the population succumbs every year. Despite the tremendous growth of the health sector, spanning diagnostics to treatment, early diagnosis is still in its infancy. In this regard, circulating tumour cells (CTCs) have of late grabbed the attention of researchers in the detection of metastasis and there has been a huge surge in the surrounding research activities. Acting as a biomarker, CTCs prove beneficial in a variety of aspects. Nanomaterial-based strategies have been devised to have a tremendous impact on the early and rapid examination of tumor cells. This review provides a panoramic overview of the different nanotechnological methodologies employed along with the pharmaceutical purview of cancer. Initiating from fundamentals, the recent nanotechnological developments toward the detection, isolation, and analysis of CTCs are comprehensively delineated. The review also includes state-of-the-art implementations of nanotechnological advances in the enumeration of CTCs, along with future challenges and recommendations thereof.

Arsenic is well known for its toxicity and various health effects. In this work, we report a simple, environment friendly and cost effective colorimetric approach for selective detection of arsenic (III) in aqueous medium. PEG functionalized silver nanoparticles were synthesized by chemical reduction method and applied for detection of heavy metal ions like arsenic(III), cobalt (II), cadmium (II), copper (II), iron (III), lead (II), mercury (II), magnesium (II) and nickel (II). In case of arsenic samples, we have observed perceptible alteration of colors from yellow to bluish due to aggregation of PEG functionalized silver nanoparticles. Absorption spectra of the arsenic samples were measured through UV–Vis spectrometry to derive detectable range of arsenic (III) concentration. The results have showed that the detection limit of this sensing unit is 1 ppb with an excellent linearity of ∼0.99. Keywords: Silver nanoparticles, Polyethylene glycol, Colorimetric, Arsenic (III)

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. In many low-income countries it causes large outbreaks and disproportionally affects pregnant women and their offspring. Surveillance studies to find effective preventive interventions are needed but are hampered by the lack of funding and infrastructure. Dried blood spots (DBS) offer an easier and more robust way to collect, transport, and store blood samples compared to plasma/serum samples, and could ease some of the barriers for such studies. In this study we optimize an HEV IgG ELISA for DBS samples and validate it on 300 paired DBS and plasma samples collected in rural areas of Bangladesh from participants in a HEV vaccine study. We demonstrate that HEV IgG in blood stored as DBS is stable for two months at up to 40 °C, and for five freeze-thaw cycles. The specificity was 97% and the overall sensitivity of the DBS assay was 81%. The sensitivity was higher in samples from vaccinated participants (100%) compared to previously infected participants (59%), reflecting a positive correlation between IgG titer and sensitivity. We found a strong correlation between DBS and plasma samples with an r2 of 0.90, but with a higher degree of difference between individual paired samples. Our study shows that DBS offers a stable alternative to plasma/serum for HEV IgG measurements and can facilitate serological studies, particularly in resource limited areas.

Cholera is a severe dehydrating illness of humans caused by Vibrio cholerae

ABSTRACT The mechanism of protection against cholera afforded by previous illness or vaccination is currently unknown. We have recently shown that antibodies targeting O-specific polysaccharide (OSP) of Vibrio cholerae correlate highly with protection against cholera. V. cholerae is highly motile and possesses a flagellum sheathed in OSP, and motility of V. cholerae correlates with virulence. Using high-speed video microscopy and building upon previous animal-related work, we demonstrate that sera, polyclonal antibody fractions, and OSP-specific monoclonal antibodies recovered from humans surviving cholera block V. cholerae motility at both subagglutinating and agglutinating concentrations. This antimotility effect is reversed by preadsorbing sera and polyclonal antibody fractions with purified OSP and is associated with OSP-specific but not flagellin-specific monoclonal antibodies. Fab fragments of OSP-specific polyclonal antibodies do not inhibit motility, suggesting a requirement for antibody-mediated cross-linking in motility inhibition. We show that OSP-specific antibodies do not directly affect V. cholerae viability, but that OSP-specific monoclonal antibody highly protects against death in the murine cholera model. We used in vivo competitive index studies to demonstrate that OSP-specific antibodies impede colonization and survival of V. cholerae in intestinal tissues and that this impact is motility dependent. Our findings suggest that the impedance of motility by antibodies targeting V. cholerae OSP contributes to protection against cholera. IMPORTANCE Cholera is a severe dehydrating illness of humans caused by Vibrio cholerae. V. cholerae is a highly motile bacterium that has a single flagellum covered in lipopolysaccharide (LPS) displaying O-specific polysaccharide (OSP), and V. cholerae motility correlates with its ability to cause disease. The mechanisms of protection against cholera are not well understood; however, since V. cholerae is a noninvasive intestinal pathogen, it is likely that antibodies that bind the pathogen or its products in the intestinal lumen contribute to protection from infection. Here, we demonstrate that OSP-specific antibodies isolated from humans surviving cholera in Bangladesh inhibit V. cholerae motility and are associated with protection against challenge in a motility-dependent manner.

Oral cholera vaccines (OCVs) are being increasingly employed, but current killed formulations generally require multiple doses and lack efficacy in young children. We recently developed a new live-attenuated OCV candidate (HaitiV) derived from a Vibrio cholerae strain isolated during the 2010 Haiti cholera epidemic. HaitiV exhibited an unexpected probiotic-like activity in infant rabbits, preventing intestinal colonization and disease by wild-type V. cholerae before the onset of adaptive immunity. However, it remained unknown whether HaitiV would behave similarly to other OCVs to stimulate adaptive immunity against V. cholerae. Here, we orally immunized adult germ-free female mice to test HaitiV's immunogenicity. HaitiV safely and stably colonized vaccinated mice and induced known adaptive immune correlates of cholera protection within 14 days of administration. Pups born to immunized mice were protected against lethal challenges of both homologous and heterologous V. cholerae strains. Cross-fostering experiments revealed that protection was not dependent on vaccine colonization in or transmission to the pups. These findings demonstrate the protective immunogenicity of HaitiV and support its development as a new tool for limiting cholera.

Wet explosion pretreatment of hybrid poplar sawdust (PSD) for the production of fermentable sugar was carried out in the pilot-scale. The effects of pretreatment conditions, such as temperature (170–190 °C), oxygen dosage (0.5–7.5% of dry matter (DM), w/w), residence time (10–30 min), on cellulose and hemicellulose digestibility after enzymatic hydrolysis were ascertained with a central composite design of the experiment. Further, enzymatic hydrolysis was optimized in terms of temperature, pH, and a mixture of CTec2 and HTec2 enzymes (Novozymes). Predictive modeling showed that cellulose and hemicellulose digestibility of 75.1% and 83.1%, respectively, could be achieved with a pretreatment at 177 °C with 7.5% O2 and a retention time of 30 min. An increased cellulose digestibility of 87.1% ± 0.1 could be achieved by pretreating at 190 °C; however, the hemicellulose yield would be significantly reduced. It was evident that more severe conditions were required for maximal cellulose digestibility than that of hemicellulose digestibility and that an optimal sugar yield demanded a set of conditions, which overall resulted in the maximum sugar yield.

The occupational health status scenario in unorganized sector is not impressive. There is a lack of awareness on occupational health and safety issues and manual labour is still obligatory. Ergonomic and work physiological studies conducted among different unorganized sector occupations are scanty. The present study intended a physiological evaluation of workload in small scale aluminium casting works. In accordance, cardiac strain of the workers is assessed in actual work situation. Seventeen regular male workers (mean age 32.6 ± 10.9; range 22 – 55) years, were examined for the magnitude of physiological strain. Different tasks performed were identified including work and rest hours. Working heart rate, net cardiac cost, relative cardiac cost and recovery heart rates were determined. Tasks performed were analysed in terms of heaviness, recommended strain level and thermal stress of the workplace. Work study revealed the predominant static nature of the tasks performed. Overall strain of the job appeared to be moderate in nature with mean working heart rate of 99 ± 5.2 beats/min. Recovery patterns were inadequate for majority of the workers. Thermal stress prevailing was more than the recommended level. The subjects were exposed to cumulative circulatory stress which might have deleterious long term effect particularly on older workers. Interventions are required to ameliorate ergonomic stressors, which indicate further scope of study.

BACKGROUND:Cholera is endemic in Bangladesh, with outbreaks reported annually. Currently, the majority of epidemic cholera reported globally is El Tor biotype Vibrio cholerae isolates of the serogroup O1. However, in Bangladesh, outbreaks attributed to V. cholerae serogroup O139 isolates, which fall within the same phylogenetic lineage as the O1 serogroup isolates, were seen between 1992 and 1993 and in 2002 to 2005. Since then, V. cholerae serogroup O139 has only been sporadically isolated in Bangladesh and is now rarely isolated elsewhere. METHODS:Here, we present case histories of four cholera patients infected with V. cholerae serogroup O139 in 2013 and 2014 in Bangladesh. We comprehensively typed these isolates using conventional approaches, as well as by whole genome sequencing. Phenotypic typing and PCR confirmed all four isolates belonging to the O139 serogroup. FINDINGS:Whole genome sequencing revealed that three of the isolates were phylogenetically closely related to previously sequenced El Tor biotype, pandemic 7, toxigenic V. cholerae O139 isolates originating from Bangladesh and elsewhere. The fourth isolate was a non-toxigenic V. cholerae that, by conventional approaches, typed as O139 serogroup but was genetically divergent from previously sequenced pandemic 7 V. cholerae lineages belonging to the O139 or O1 serogroups. CONCLUSION:These results suggest that previously observed lineages of V. cholerae O139 persist in Bangladesh and can cause clinical disease and that a novel disease-causing non-toxigenic O139 isolate also occurs.