Quantifying Defects and Finite Size Effects in Graphene Oxide Models

Oxidation of graphite and subsequent exfoliation leads to single layer graphene oxide (GO). GO has found many applications across diverse fields including medicinal chemistry, catalysis as well as a precursor for graphene. One of the key structural features of GO is the presence of different kinds of defects. Molecular dynamics simulations with ReaxFF force fields have been widely used to model realistic representations of GO that include defects of various types. In these simulations, one can vary the extent and distribution of the defects by changing the initial O/C ratio. It is therefore very important to employ a proper measure of the defect density. Traditionally, the total number of non-graphitic carbon atoms have been employed to quantify the amount of defects. Our simulations suggest that this parameter may not be a good measure at low defect densities. Herein, we introduce a hitherto unexplored metric, relative area of the defects, to gauge the defect density. We show that this metric has desirable properties at both low and high defect densities. Additionally, we investigate the changes in the defect distribution and mechanical properties upon varying the size of the simulation cell

Bone Mineral Density, Serum Calcium, and Vitamin D Levels in Adult Thalassemia Major Patients: Experience From a Single Center in Eastern India

Background and objective Patients suffering from thalassemia major are at higher risk of osteoporosis. Due to their decreased life expectancy, the number of adult patients is low. However, their bone health is rarely checked in developing countries like India. There is no data available in the literature on the bone mineral density (BMD) of adult (aged ≥18 years) thalassemia major patients in eastern India. In this study, we aimed to measure the BMD and serum calcium and vitamin D levels in adult thalassemia major patients and to compare them with healthy controls. Materials and methods We conducted this cross-sectional observational study at a tertiary care hospital in eastern India. We recruited adult thalassemia major patients who were not on calcium or vitamin D supplements. Their BMD was measured by dual-energy X-ray absorptiometry (DXA) on the lumbar spine (L1-L4). Venous blood was tested for serum calcium and vitamin D levels. We compared the parameters between the cases and controls by using the Mann-Whitney U test. Results A total of 31 (male = 19, female = 12) patients with a median age of 28 years comprised the case group. Age- and sex-matched controls showed similar height but higher weight and BMI. The serum calcium level was similar (p = 0.43) in the case and control groups but T-score (p = 0.0003) and vitamin D levels (p

Optimisation using central composite design (CCD) and the desirability function for sorption of methylene blue from aqueous solution onto Lemna major

AbstractWater pollution due to contamination of dye containing effluents is a great threat to water body. A study on the biosorption of methylene blue (MB) onto low-cost Lemna major biomass was conducted and the process parameters were optimized by response surface methodology (RSM). A two-level, four-factor central composite design (CCD) has been employed to determine the effect of various process parameters namely initial concentration (600–1000 mg L−1), bioadsorbent dose (0.20–1.50 g/100 mL), pH (5–12) and stirring rate (250–800 rpm) on MB uptake from aqueous solution. By using this design a total of 30 biosorption experimental data were fitted. The regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination (R2) value of 0.9978 and model F-value of 953.48. The optimum conditions of initial concentration (1000 mg L−1), adsorbent dose (0.2 g), pH (5) and stirring rate (251.51 rpm) were recorded from desirability function. The adsorption isotherm data were best described by both Freundlich and Langmuir models with a maximum adsorption capacity of 488 mg MB g−1 L. major biomass at 30 °C which is higher than that available with adsorbents used by past researchers. Finally the pseudo second order kinetic model described the MB biosorption process with a good fitting (R2 = 0.999). The adsorbent was characterised by scanning electron micrograph (SEM) and Fourier transform infrared spectroscopy (FTIR)

Nephrocutaneous fistula due to textiloma with in the pelvicalyceal system

Textiloma or gossypiboma is an embarrassing surgical scenario. Nephrocutaneous fistula is itself a rare complication after renal surgeries, but due to textiloma, it is rarest of the rare. In this case, 30-year-old lady presented with the complaints of chronic seropurulent discharge from a wound on her right lumbar region. On exploration it was found to be a retained surgical sponge in pelvicalyceal system, which was there for last seven years

CLINICAL AND AUTOIMMUNE CHARACTERISTICS OF COVID-19 PATIENTS IN A TERTIARY CARE CENTRE: A CROSS-SECTIONAL STUDY

Introduction: Since the end of 2019, the world is witnessing the emergence of the coronavirus disease 2019 (COVID-19) outbreak and pandemic caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This disease presented with a wide array of clinical, inflammatory and possible autoimmune manifestations. Currently, a very few data is available about the involvement of autoimmunity in patients affected by coronavirus disease 2019 (COVID-19). Aim: To find out the clinical and inflammatory status of COVID-19 patients and whether this disease (SARS-CoV-2) stimulates autoantibody production and contributes to autoimmunity activation. Methodology: A hospital based retrospective study conducted on 60 COVID-19 patients. All patients were clinically and radiologically evaluated and screened for common inflammatory markers and auto antibodies. Result: Patients included were 39 men (65%) and 21 women (35%). 33 patients were mild cases, 15 were moderate and 12 were severe cases with a mean age of 44.27. Fever and shortness of breath were the dominant symptoms; most patients had at least one coexisting disorder on admission; the most common characteristic on chest CT was groundglass opacity; the most common findings on laboratory measurements of inflammatory markers were elevated levels of CRP, LDH ,ferritin and altered neutrophil lymphocyte ratio; and prevalence of autoantibodies ,anti SSA/Ro antibody, anti SSB/La antibody, and antinuclear antibody was 20%, 10%, and 15%, respectively and Anti-TPO antibody was positive in 33.3% patients. Conclusion: We conclude that autoimmune phenomena exist in COVID-19 subjects.

FREQUENCY AND PREDICTORS OF HEPATOPULMONARY SYNDROME IN CHRONIC LIVER DISEASE PATIENTS

Introduction: Hepatopulmonary syndrome is not very uncommon among chronic liver disease patients in clinical practice.It is associated with shorter survival and poor liver function in cirrhotics. Although there are a large number of CLD patients in India, the exact frequency of HPS is not known & it needs evaluation. Aims: To estimate the frequency of hepatopulmonary syndrome among Indian patients with chronic liver disease, study the correlation between HPS and the severity of liver disease and assess the factors predictive for diagnosis of HPS. Methodology: A cross sectional study on total fifty patients (34 males, mean age 44.4 ± 7.3years) with chronic liver disease was conducted to diagnose the presence of hepatopulmonary syndrome. Patients were subjected to clinical examination, laboratory investigations, measurement of arterial blood gas and transthoracic contrast enhanced echocardiography. The severity of liver disease was assessed by Child-Pugh score.The diagnostic criteria for HPS were presence of intrapulmonary vascular dilatation(IPVD) documented by contrast enhanced echocardiography and alveolar arterial oxygen gradient of more than 15 mm Hg. Results:.Nine of fifty patients (18%) with chronic liver diseas were found to have contrast echocardiographic evidence of intrapulmonary vasodilatation. Hepatopulmonary syndrome was observed in seven (14%) patients.We did not find any significant correlation between presence of HPS with severity of liver disease according to the Child-Pugh score. Features like dyspnoea, orthopnea, cyanosis, clubbing, platypnoea and orthodeoxia were significantly more common in the HPS group. Conclusions: The frequency of HPS among the studied group of Indian patients with chronic liver disease was 14%. Though there was no significant correlation between presence of HPS with severity of liver disease according to the Child-Pugh score ; but presence of cyanosis, clubbing, dyspnoea and platypnoea–orthodeoxia are suggestive indicators of HPS

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe