A synergistic approach to enhance sensitivity and selectivity of room temperature operable ammonia gas sensor with humidity assistance using RGO/WO3nanocomposite.

In this study, the fabrication of an ultrahigh selective NH3gas sensor based on RGO/WO3nanocomposite has been proposed. The hydrothermal method was employed to synthesize the RGO/WO3nanocomposite. The formation of RGO/WO3nanocomposite and the elemental composition, structure and morphology of the as-synthesized materials were confirmed through an array of analytical techniques, including XRD, Raman, FT-IR, XPS and TEM. For gas sensing applications, pure RGO and RGO/WO3have effectively spin-coated onto the interdigitated electrodes (IDE's) based on fluorine doped tin oxide (FTO) respectively, and their sensitivity towards NH3was tested. Gas sensing characteristics of prepared materials were analyzed at room temperature (25 °C) under different relative humidity (RH) levels. The developed RGO/WO3sensor was subjected to different NH3concentrations, demonstrating a high sensing response of 89% towards 500 ppm NH3under 11%-97%-11% RH conditions. Notably, the sensor exhibited rapid response and recovery times with an average response time of 92 s and recovery time of 26 s when exposed to 500 ppm NH3under the specified RH conditions. To gauge the material selectivity, the prepared nanocomposite was exposed to a range of volatile organic compounds and the results showcased the sensor's remarkable selectivity and sensitivity specifically toward NH3vapor. This superior performance can be attributed to the abundant active sites and the excellent electron transport properties inherent to the RGO component. Importantly, the RGO/WO3sensor displayed high reproducibility and consistent responses, with minimal degradation (1.98% degradation) over 30 d at 11%-97%-11% RH. Furthermore, we examined the sensor's response with varying levels of relative humidity to assess its potential for real-world applications. The sensor exhibited extremely low power consumption, outperforming a commercially available metal oxide sensor while operating at ambient temperature. The robust performance of RGO/WO3coupled with low power requirements and ambient temperature operation, positions it as a promising candidate for next-generation gas sensing technologies.

Electron Attachment to Wobble Base Pairs.

We have analyzed the low-energy electron attachment to wobble base pairs using the equation of motion coupled cluster method and extended basis sets. A doorway mechanism exists for the attachment of the additional electron to the base pairs, where the initially formed dipole-bound anion captures the incoming electron. The doorway dipole-bound anionic state subsequently leads to the formation of a valence-bound state, and the transfer of extra electron occurs by mixing of electronic and nuclear degrees of freedom. The formation of the valence-bound anion is associated with proton transfer in hypoxanthine-cytosine and hypoxanthine-adenine base pairs, which happens through a concerted electron-proton transfer process. The calculated rate constant for the dipole-bound to valence-bound transition in wobble base pairs is slower than that observed in the Watson-Crick guanine-cytosine base pair.

Comparative Analysis of Collagen and Chitosan-based Dressing for Haemostatic and Wound Healing Application.

Collagen and chitosan have haemostatic, tissue fix and wound healing properties but the poor mechanical property limits their application. Therefore, various concentrations of collagen (1-6%) and chitosan (1-2%) were used to develop biopolymer-coated gauzes, with and without glycerol as plasticiser. Glycerol-treated gauzes showed desired mechanical and adhesive property in comparison to polymer-coated gauzes alone. Developed gauzes were characterized using differential scanning calorimetry, thermal gravimetric analysis and Fourier transform infrared spectrophotometry to confirm the biopolymer coating and stability. Scanning electron microscopy showed multilayer coating of the biopolymer and faster clotting in chitosan gauzes in comparison to collagen. Surface plasmon resonance assay confirmed that chitosan exhibited more binding affinity of 65 RU in comparison to collagen, which showed 55 RU with erythrocytes. Decrease in the value of plateletcrit and mean platelet volume confirmed platelet adhesion and aggregation over the surface of polymer-coated dressings. Gamma scintigraphy studies showed 85 ± 2% formulation retention up to 12 h at the wound site in comparison to 40 ± 3% retention of the radiopharmaceutical alone. Collagen and chitosan-coated gauze showed 226 ± 15 s and 179 ± 12 s haemostasis time, respectively, which was significantly less from 506 ± 15 s in standard gauze. Chitosan gauze showed faster wound healing in comparison to the collagen-coated gauze. Chitosan and collagen-coated gauzes showed 55 ± 4% wound contraction on day seven in comparison to 25 ± 2% in the control group, while chitosan gauzes showed complete wound contraction on day fourteenth, while the collagen-coated gauze showed 90 ± 3% on the same day.

Fabrication of Three-Dimensional Bioactive Composite Scaffolds for Hemostasis and Wound Healing.

Fabrication of 3D composite scaffolds was carried out by lyophilization of variable concentrations of collagen and chitosan gel solutions. Fibrinogen and thrombin aerosol were deposited over the surface of scaffolds to enhance hemostasis and wound healing. Composite scaffolds were characterized using differential scanning calorimetry, thermogravimetric analysis, and Fourier-transform infrared spectrophotometer to ascertain the aerosol deposition and stability. Scanning electron microscope showed multilayered porosity with pore size of ~30 µm and mushroom-like fibril growth of aerosol. A detailed investigation by surface plasmon resonance confirmed higher binding affinity of collagen toward the human blood platelets and erythrocytes in comparison to chitosan and was found to increase with the increase in blood cell concentration from 480.8 to 886.4 RU for erythrocytes. Scaffolds showed higher binding response for platelets than erythrocytes, while fibrinogen and thrombin showed no or limited interaction. Highest blood sorption of 83 ± 4% was observed in case of aerosol deposited scaffolds. Aerosol deposited scaffolds showed minimum clotting time of 20 ± 3 s and bleeding time of 38 ± 4 s, which was significantly lower compared to the scaffolds without aerosol treatment. Aerosol deposited composite scaffolds with 2:1 concentration of chitosan/collagen showed complete wound contraction by day 14, while 50% was observed in case of the control group. In vivo studies revealed that chitosan had a crucial role in the inflammatory phase, while collagen played an important role in the proliferation and maturation phase. The present study suggests that the fabricated 3D composite scaffolds with bioactive moieties may be a potential candidate for enhanced hemostasis and wound healing applications.

Water mediated electron attachment to nucleobases: Surface-bound vs bulk solvated electrons.

We have presented a mechanism for electron attachment to solvated nucleobases using accurate wave-function based hybrid quantum/classical (QM/MM) simulations and uracil as a test case. The initial electron attached state is found to be localized in the bulk water, and this water-bound state acts as a doorway to the formation of the final nucleobase bound state. The electron transfer from water to uracil takes place because of the mixing of electronic and nuclear degrees of freedom. The water molecules around the uracil stabilize the uracil-bound anion by creating an extensive hydrogen-bonding network and accelerate the rate of electron attachment to uracil. The complete transfer of the electron from water to the uracil occurs in a picosecond time scale, which is consistent with the experimentally observed rate of reduction of nucleobases in the presence of water. The degree of solvation of the aqueous electron can lead to a difference in the initial stabilization of the uracil-bound anion. However, the anions formed due to the attachment of both surface-bound and bulk-solvated electrons behave similarly to each other at a longer time scale.

Electron Attachment to DNA Base Pairs: An Interplay of Dipole- and Valence-Bound States.

We have investigated the electron-attached states in Watson-Crick guanine-cytosine and adenine-thymine base pairs using the highly accurate equation-of-motion coupled-cluster (EOM-CC) method and extended basis sets. Both base pairs have two bound anionic states. The dipole-bound state is stable even at the neutral geometry, but the valence-bound state is only adiabatically bound. The initial electron attachment results in the formation of a dipole-bound state that acts as a doorway to the valence-bound anionic state. The adiabatic potential energy surface of ground and first excited states of an anion shows an avoided crossing, indicating mixing of the electronic and nuclear degrees of freedom. We have calculated the coupling strength between the valence- and dipole-bound states by fitting a simple diabatic model potential to a cut through the two adiabatic surfaces of the anions obtained from the EOM-CC calculations. The transfer of the electron from the initial dipole-bound to the final valence-bound state has been found to happen at an ultrafast time scale.

Transition metal catalysis-a unique road map in the stereoselective synthesis of 1,3-polyols.

The present review summarizes recent diverse reactions employed in the formation of 1,3-polyols providing an overview of the mechanistic pathway and the enantioselectivity obtained, in terms of the properties of transition metals directly involved in the catalytic transformations and their interaction with various ligands.

Development of "DiabetesSutra" a mobile application for lifestyle management of Type 2 Diabetes in India.

Background: Multiple mhealth (mobile health) interventions and mobile applications have been developed to support diabetes self-management. However, most of the apps are developed without the need for assessment and evaluation by experts in the field. This study aimed to design and develop a mobile application (app) supporting diabetes self-management for people with Type 2 Diabetes Mellitus (T2D) using a systematic approach. Methods: In this study mixed method design was used to develop the mobile application. The mhealth intervention was designed and developed in five steps: i) Extensive literature search, ii) Needs assessment of patients with T2D with the help of healthcare providers and patients (Interviews with 15 healthcare providers like clinicians, dietitians, and diabetes educators, and 2 focus group discussions with patients) iii) Ideation and content development of app based on outcomes of needs assessment; iv) content validation (by 10 healthcare providers) and v) App development on a hybrid platform. Evaluation of the app by users i.e., type 2 diabetes patients was done using the users' Mobile App rating scale (uMARS). The app was evaluated by 40 patients and rated on the uMARS questionnaire. Results: A patient-centric mobile app was developed for the nutritional management of diabetes with three modules: The patient module, the Evaluation module, and the Healthcare provider module. The patient module was the app that was provided to the patients with features like diet, physical activity, blood glucose log, education, etc., in addition to, a symptom checker, Stress meter blog, and FAQ. The evaluation module was integrated with the app it works when a user enters any log, it evaluates the entry against the standard cutoffs and flash prompts on the screen. The Healthcare provider module interacts with the server to provide them with patient data, comments, and feedback. Conclusions: The users found the app to be satisfactory. Incorporating additional features to enhance the user interface and streamline navigation could potentially enhance user engagement, thereby aiding in the management of T2D.

Dietary pattern associated with non-alcoholic fatty liver disease (NAFLD) in non-diabetic adult patients: A case control study.

BACKGROUND: Dietary intake is an important factor in the development and management of non-alcoholic fatty liver disease (NAFLD) however, optimal food group composition remains unclear. Data on detailed food group intake of NAFLD patients from India is scarce. METHODS & MATERIALS: In this study with 320 participants (160 NAFLD cases and 160 controls), dietary habits were assessed using a 24-h dietary recall for two days and a validated 142-item food frequency questionnaire over the past year. Principal component analysis identified dietary patterns associated with NAFLD among the participants. RESULTS: Cases were having a significantly higher intake of edible oils and fats along with nuts and oilseeds as compared to controls (p < 0.05). There was a positive and significant association with edible oils and fats with NAFLD [OR (95 % CI):1.7 (1.11-2.49) p = 0.013). In dietary pattern analysis western dietary pattern was found to be a risk for NAFLD whereas protective dietary pattern was associated with the decreased risk of NAFLD. CONCLUSION: The overall food groups intake in NAFLD cases and controls was low suggesting lower diet quality. Protective dietary pattern found to be beneficial for NAFLD. High intake of sugars and edible oils associated with western dietary pattern increases the risk of NAFLD.

Production, purification and characterization of cholesterol oxidase from a newly isolated Streptomyces sp.

Cholesterol oxidase production (COD) by a new isolate characterized as Streptomyces sp. was studied in different production media and fermentation conditions. Individual supplementation of 1 % maltose, lactose, sucrose, peptone, soybean meal and yeast extract enhanced COD production by 80-110 % in comparison to the basal production medium (2.4 U/ml). Supplementation of 0.05 % cholesterol (inducer) enhanced COD production by 150 %. COD was purified 14.3-fold and its molecular weight was found to be 62 kDa. Vmax (21.93 µM/min mg) and substrate affinity Km (101.3 µM) suggested high affinity of the COD for cholesterol. In presence of Ba(2+) and Hg(2+) the enzyme activity was inhibited while Cu(2+) enhanced the activity nearly threefold. Relative activity of the enzyme was found maximum in triton X-100 whereas sodium dodecyl sulfate inactivated the enzyme. The enzyme activity was also inhibited by the thiol-reducing reagents like Dithiothreitol and ß-mercaptoethanol. The COD showed moderate stability towards all organic solvents except acetone, benzene and chloroform. The activity increased in presence of isopropanol and ethanol. The enzyme was most active at pH 7 and 37 °C temperature. This organism is not reported to produce COD.

Barriers and facilitators in dietary and physical activity management of type 2 diabetes: Perspective of healthcare providers and patients.

BACKGROUND AND AIMS: Type 2 diabetes (T2DM) is a chronic disease that requires continuous management and daily self-care activities. The purpose of the study was to identify the barriers and facilitators in dietary and physical activity management of T2DM by patients. METHOD: Two focus group discussions with patients with T2DM (n = 12) and interviews with healthcare providers (HCPs, n = 15) were done, to identify the barriers and facilitators experienced by patients towards lifestyle management in T2DM. Data were analyzed using qualitative data analysis software Atlas ti. version 8. RESULT: Three major themes were identified as barriers and facilitators viz., Personal barriers and facilitators, social barriers and facilitators, and barriers and facilitators related to the healthcare provider. Major barriers were denial of illness, low level of knowledge of the disease, excess use of gadgets, poor infrastructure, gender issues, and lack of time. Major facilitators identified were patient education and motivation, continuous counseling and regular follow-up, family and peer support, and recreational and indoor activities. CONCLUSION: Based on the findings of the study, a multifaceted approach is required to address these barriers and facilitators. These findings will help in developing novel intervention strategies and making policy-level changes, which are required to improve diabetes self-management practices in people with T2DM.

Secondary Electron Attachment-Induced Radiation Damage to Genetic Materials.

Reactions of radiation-produced secondary electrons (SEs) with biomacromolecules (e.g., DNA) are considered one of the primary causes of radiation-induced cell death. In this Review, we summarize the latest developments in the modeling of SE attachment-induced radiation damage. The initial attachment of electrons to genetic materials has traditionally been attributed to the temporary bound or resonance states. Recent studies have, however, indicated an alternative possibility with two steps. First, the dipole-bound states act as a doorway for electron capture. Subsequently, the electron gets transferred to the valence-bound state, in which the electron is localized on the nucleobase. The transfer from the dipole-bound to valence-bound state happens through a mixing of electronic and nuclear degrees of freedom. In the presence of aqueous media, the water-bound states act as the doorway state, which is similar to that of the presolvated electron. Electron transfer from the initial doorway state to the nucleobase-bound state in the presence of bulk aqueous media happens on an ultrafast time scale, and it can account for the decrease in DNA strand breaks in aqueous environments. Analyses of the theoretically obtained results along with experimental data have also been discussed.

Prevalence of sarcopenia and its determinants in people with type 2 diabetes: Experience from a tertiary care hospital in north India.

OBJECTIVES: Changes in skeletal muscle mass and quality are associated with type 2 Diabetes (T2D) and its complications. We evaluated the prevalence of sarcopenia in patients with T2D and its association with various anthropometric and metabolic parameters. METHODS: A total of 229 patients with T2D, ≥20-60 years, were screened for sarcopenia using handgrip strength (HGS) by dynamometer, physical performance test (by Short Physical and chair stand test), and height-adjusted appendicular skeletal muscle index (ASMI) by Dual Energy X-ray Absorptiometry (DXA) applying Asian Working Group on Sarcopenia (AWGS). Multiple logistic regressions were performed to identify the factors associated with sarcopenia. RESULTS: The mean age was 46.2 ± 7.4 years with 55% being women. The prevalence of low HGS, poor physical performance, low ASMI, possible sarcopenia, sarcopenia, and severe sarcopenia was 16.2%, 39.3%, 33%, 43%, 18.8%, and 6.1%, respectively. Age >45 years and use of >2 oral hypoglycaemic agents (OHA's) were risk factors for low HGS (OR:3.51, 95%CI = 1.5-8.3) and low ASMI (OR:2.40, 95%CI = 1.05, 5.49, p-0.04), respectively. Female sex (OR:3.3 1.8-6.1 p < 0.01), age >45 years (OR:2.12, 95% CI = 1.2-3.8 p-0.012) and liver fibrosis (OR: 2.12, 95% CI = 1.01-4.46 p-0.048) were independently associated with poor performance. No association was found with HbA1c, dyslipidaemia, albuminuria, hypertension, or duration of diabetes and sarcopenia. CONCLUSION: Sarcopenia is becoming increasingly recognized as a significant complication in younger individuals with T2D, and poor physical performance plays a vital role in its development. The prevalence of sarcopenia rises with advancing age, underscoring the importance of early intervention to address this condition.

How Indian obese population managed their lifestyle during first and second lockdown during COVID-19 pandemic? - A comparative study.

Background: People from all over the world have been affected by the COVID-19 (SARS-CoV-2) pandemic. The lockdown during the pandemic has impacted the lifestyle of most of the population. The aim of the present study is to compare the effect of COVID lockdown-1 and lockdown-2 on the lifestyle of the obese Indian population. Methods: This was a cross-sectional study conducted during the COVID-19 lockdown on obese adults. A well-structured questionnaire was developed and administered among the study population. The study was conducted in two phases (lockdown-1 and lockdown-2). A total of 390 subjects were included in the study (260 subjects in the lockdown-1 phase and 130 subjects in the lockdown-2 phase). Data on diet, sleep, stress, and physical activity were obtained and analyzed. Results: The mean age of the participants of phase-1 in the study was 41.7 ± 10.2 years and the participants of phase-2 were 44.5 ± 9.2 years. Statistically significant differences were observed between lockdown-1 and lockdown-2 in terms of monitoring of weight and other comorbid conditions, changes in the consumption of refined flour and processed foods, sugar and sugar-sweetened foods, oils and ghee, duration of physical activity, changes in the duration of sleep, and the stress levels related to COVID-19 (P < 0.001). Conclusion: The impact of the lockdowns on health was very significant and different areas of lifestyle were affected in both the lockdowns. Weight gain was reported in both phases of the lockdown. The monitoring of health parameters, eating frequency, diet, and stress levels were affected during lockdown-1, whereas during lockdown-2, sleep duration and physical activity were affected. A comprehensive lifestyle modification plan is required to be developed to avoid these effects in the future.

Doorway Mechanism for Electron Attachment Induced DNA Strand Breaks.

We report a new doorway mechanism for the dissociative electron attachment to genetic materials. The dipole-bound state of the nucleotide anion acts as the doorway for electron capture in the genetic material. The electron gets subsequently transferred to a dissociative σ*-type anionic state localized on a sugar-phosphate or a sugar-nucleobase bond, leading to their cleavage. The electron transfer is mediated by the mixing of electronic and nuclear degrees of freedom. The cleavage rate of the sugar-phosphate bond predicted by this new mechanism is higher than that of the sugar-nucleobase bond breaking, and both processes are considerably slower than the formation of a stable valence-bound anion. The new mechanism can explain the relative rates of electron attachment induced bond cleavages in genetic materials.

Efficient EOM-CC-based Protocol for the Calculation of Electron Affinity of Solvated Nucleobases: Uracil as a Case Study.

We present an explicit solvation protocol for the calculation of electron affinity values of the solvated nucleobases. The protocol uses a quantum mechanics/molecular mechanics (QM/MM) approach based on the newly implemented domain-based pair natural orbital EOM-CCSD (equation-of-motion coupled-cluster single-double) method. The stability of the solvated nucleobase anion is sensitive to the local distribution of the water molecules around the nucleobase, and the calculated electron affinity values converge slowly with respect to the number of snapshots and the size of the water box. The use of nonpolarizable water molecules leads to an overestimation of the electron affinity and makes the result sensitive to the size of the QM region in the QM/MM calculation. The electron affinity values, although sensitive to the size of the basis set, lead to an almost constant blue shift of the electron affinity upon the increase in the basis set. The present protocol allows for a controllable description of the various parameters affecting the electron affinity value, and the calculated adiabatic electron affinity values are in excellent agreement with experimental results.

Nutritional regulation of actinomycin-D production by a new isolate of Streptomyces sindenensis using statistical methods.

Production of actinomycin-D, by an isolate, S. sindenensis, was optimized by statistical methods. Fructose peptone and NaNO3 were found to be critical for antibiotic production. In the second step, their concentrations were optimized with Central Composite Design and Response Surface Methodology. Fructose, peptone and NaNO3 at 2.55, 0.309 and 0.114% respectively gave approximately 261% higher yield (289 mg/l). Cultivation in fermentor at 600 rpm agitation and 1.5 vvm aeration with optimized medium gave 3.56 folds higher yield (365 mg/l) as compared to the yields in shake flasks using normal production medium (80 mg/l).

Microbial diversity--biotechnological and industrial perspectives.

Biodiversity is an addition sum of the studies on genetic, taxonomic commercial and ecosystem aspects of living systems. All the living individuals of a species contain a distinct combination of genes and the intrinsic interaction among the gene pool influences evolution, survival and phenotypic/genotypic changes of the part of the biodiversity i.e. community. The amount of genetic diversity within population varies tremendously and much of modern conservation biology is concerned with the maintenance of genetic diversity within the population of plants, animals and microbes. Germplasm, obtained with the vast biodiversity, provides a major source of biological material for the development of medicines, vaccines, pharmaceutical products, improved crop and animal varieties and for other environmental applications. Industrialized nations, who have the technology and resources to patent and develop commercial biological products, are having the benefits of biodiversity through the collected and conserved germplasm flowing through the international research centers. In fact a particular genetic contribution usually represents only a small percentage of the total value of the eventual products. In addition, the research and development process required to commercialize a particular product requires enormous technical efforts. The principle of patenting genes is the morally or ethically correct is a matter of intense debate. However, geneticists, having conceived of the technologies with vast and immediate therapeutic, food and environmental values must try to bring to the material to market as soon as possible.

Isolation, characterization and antifungal docking studies of wortmannin isolated from Penicillium radicum.

During the search for a potent antifungal drug, a cell-permeable metabolite was isolated from a soil isolate taxonomically identified as Penicillium radicum. The strain was found to be a potent antifungal agent. Production conditions of the active compound were optimized and the active compound was isolated, purified, characterized and identified as a phosphoinositide 3-kinase (PI3K) inhibitor, commonly known as wortmannin (Wtmn). This is very first time we are reporting the production of Wtmn from P. radicum. In addition to its previously discovered anticancer properties, the broad spectrum antifungal property of Wtmn was re-confirmed using various fungal strains. Virtual screening was performed through molecular docking studies against potential antifungal targets, and it was found that Wtmn was predicted to impede the actions of these targets more efficiently than known antifungal compounds such as voriconazole and nikkomycin i.e. 1) mevalonate-5-diphosphate decarboxylase (1FI4), responsible for sterol/isoprenoid biosynthesis; 2) exocyst complex component SEC3 (3A58) where Rho- and phosphoinositide-dependent localization is present and 3) Kre2p/Mnt1p a Golgi alpha1,2-mannosyltransferase (1S4N) involved in the biosynthesis of yeast cell wall glycoproteins). We conclude that Wtmn produced from P. radicum is a promising lead compound which could be potentially used as an efficient antifungal drug in the near future after appropriate structural modifications to reduce toxicity and improve stability.