Interfacial Adsorption Kinetics of Methane in Microporous Kerogen.

Rapid declines in unconventional shale production arise from the poorly understood interplay between gas transport and adsorption processes in microporous organic rock. Here, we use high-fidelity molecular dynamics (MD) simulations to resolve the time-varying adsorption of methane gas in realistic organic rock samples, known as kerogen. The kerogen samples derive from various geological shale fields with porosities ranging between 20% and 50%. We propose a kinetics sorption model based on a generalized solution of diffusive transport inside a nanopore to describe the adsorption kinetics in kerogen, which gives excellent fits with all our MD results, and we demonstrate it scales with the square of the length of kerogen. The MD adsorption time constants for all samples are compared with a simplified theoretical model, which we derive from the Langmuir isotherm for adsorption capacitance and the free-volume theory for steady, highly confined bulk transport. While the agreement with the MD results is qualitatively very good, it reveals that, in the limit of low porosity, the diffusive transport term dominates the characteristic time scale of adsorption, while the adsorption capacitance becomes important for higher pressures. This work provides the first data set for adsorption kinetics of methane in kerogen, a validated model to accurately describe this process, and a qualitative model that links adsorption capacitance and transport with the adsorption kinetics. Furthermore, this work paves the way to upscale interfacial adsorption processes to the next scale of gas transport simulations in mesopores and macropores of shale reservoirs.

Occupational Ventilatory Defects Among Workers Employed in Tea Gardens, A Cross-Sectional Study in Siliguri Subdivision of Darjeeling District, West Bengal.

Introduction: During the refining and packing of tea, a very fine dust is formed which is called the tea fluff. Exposure to this fluff has been reported to cause ventilatory defects on chronic exposure. Objective: To determine the association between air quality of the different work sections of tea gardens and the ventilatory functions of the workers. Methodology: An observational analytical study with cross sectional design was conducted on 400 apparently healthy individuals working in different sections of 4 tea gardens. Data on sociodemographic characters of the population, particulate matter (PM) and air quality (AQI) was recorded. All participants underwent spirometric evaluation. Results: The mean (SD) age of the study population was 37.8 (8) years. Most (67%) of the study participants were females. The participants were engaged in the job for a mean (SD) of 4.7 (2.7) years. The median distribution of PM2.5, PM 10 and AQI are progressively higher from the garden section to the dry section. A significant correlation between FVC and PM2.5 and PM10 is seen. FEV1 and FEV1/FVC shows a significant correlation with all air quality parameters while FEF25-75 is correlated to none of them. Comparison of the three models to predict the spirometric variables show that even after adjustments, the FEV1 is significantly associated with air quality parameters, FEV1/FVC is significantly associated with the air quality parameters and age while the FEF25-75% is dependent on the age of the participant. Conclusion: There is a strong correlation between the ventilatory parameters and the cumulative exposure of PM2.5, PM10 and AQI, which persists even after adjustment for confounders.

Pulmonary Involvement in Systemic Lupus Erythematosus Patients in a Tertiary Care Hospital.

INTRODUCTION: In half of the individuals with systemic lupus erythematosus (SLE), over the course of the disease, pulmonary involvement occurs frequently and is one of the parts in the array of presenting symptoms. But the published research and information on SLE have historically concentrated on renal, central nervous system (CNS), and dermatological manifestations, while the pulmonary effects of SLE have received very less attention. OBJECTIVE: To know the extent and pattern of pulmonary involvement in SLE patients in a tertiary care hospital. MATERIALS AND METHODS: A cross-sectional observational study was conducted among 70 diagnosed SLE [who fulfilled the revised American College of Rheumatology (ACR) criteria for the classification of SLE] patients attending a tertiary care center. Seventy diagnosed SLE patients who met the updated ACR criteria for the classification of SLE and were enrolled in a tertiary care facility in West Bengal participated in a cross-sectional observational study. After informed consent, clinical examinations, general survey, respiratory examination, cardiovascular examination, and relevant investigations [chest X-ray, pulmonary function test, echocardiography and electrocardiography, and high-resolution computed tomography (HRCT)/chest computed tomography (CT) scan] were performed. RESULTS: The majority of the study subjects belonged to the 21-30 years of age-group (45.7%) and were females. Most of the study subjects were treatment-naïve as they were newly diagnosed. Among the chief presenting complaints, the most common was cough followed by dyspnea and pleuritic chest pain. Chest X-rays showed pleural pathology in 37% of study subjects and pulmonary function tests were found to have a restrictive pattern in 4.3%. Echocardiography documented that 19.6% had pulmonary artery hypertension. HRCT revealed that 19.4% of subjects had definitive findings of interstitial lung diseases (ILD). CONCLUSION: A substantial contributor to morbidity and death, SLE is a potentially fatal, commonly debilitating autoimmune illness with pulmonary symptoms. Cough was the most common presenting complaint, and the most common radiological abnormality detected was pleural effusion. Spirometry revealed, as expected, a restrictive pattern in most of the cases. Around 29% of cases revealed features suggestive of or confirmatory evidence for intestinal lung disease. As a whole, the prevalence of lung involvement in SLE in the study was 67%. But this being a study with only 70 participants, a further longitudinal is recommended to study disease activity correlation with the incidence of early pulmonary involvement in SLE disease course.

Impact of surface nanostructure and wettability on interfacial ice physics.

Ice accumulation on solid surfaces is a severe problem for safety and functioning of a large variety of engineering systems, and its control is an enormous challenge that influences the safety and reliability of many technological applications. The use of molecular dynamics (MD) simulations is popular, but as ice nucleation is a rare event when compared to simulation timescales, the simulations need to be accelerated to force ice to form on a surface, which affects the accuracy and/or applicability of the results obtained. Here, we present an alternative seeded MD simulation approach, which reduces the computational cost while still ensuring accurate simulations of ice growth on surfaces. In addition, this approach enables, for the first time, brute-force all-atom water simulations of ice growth on surfaces unfavorable for nucleation within MD timescales. Using this approach, we investigate the effect of surface wettability and structure on ice growth in the crucial surface-ice interfacial region. Our main findings are that the surface structure can induce a flat or buckled overlayer to form within the liquid, and this transition is mediated by surface wettability. The first overlayer and the bulk ice compete to structure the intermediate water layers between them, the relative influence of which is traced using density heat maps and diffusivity measurements. This work provides new understanding on the role of the surface properties on the structure and dynamics of ice growth, and we also present a useful framework for future research on surface icing simulations.

Prevalence of Risk Factors of Non-communicable Diseases among Adolescents of a Rural Area in Darjeeling District of West Bengal.

INTRODUCTION: Adolescence is the transitional period between childhood and adulthood when new health behaviors are laid down, which may track in to adulthood and have lifelong impact. Global trends show that these NCD-related behaviors are gradually rising among young people, and that they establish patterns of behavior that persist throughout life and are often hard to alter. OBJECTIVE: To find out the prevalence and socio demographic predictors of risk factors of non communicable diseases among adolescents of a rural area Methods: A community based cross sectional study was conducted among 365 adolescents residing in a rural area of Siliguri subdivision. They were interviewed and measurements were taken using standard procedure. RESULTS: The prevalence of behavioural factors for NCDs like tobacco use, alcohol use, unhealthy diet, physically inactivity was 18.4%, 4.7%, 87.1% and 23.0% respectively; metabolic risk factors like overweight, hypertension, and abdominal obesity 28.5%, 17.5%, 1.4% respectively. After adjustment, the odds of behavioural and metabolic risk factors were found highest among the males, participants whose mothers were not working and those who belonged to Hindu families and lower socioeconomic class. CONCLUSION: The proportion of risk factors of non communicable diseases among the rural adolescents was quite high'. Given the associated health problems and costs, non communicable diseases have become an issue of serious concern.

Acoustothermal Nucleation of Surface Nanobubbles.

Ultrasonic surface vibration at high frequencies (O(100 GHz)) can nucleate bubbles in a liquid within a few nanometres from a surface, but the underlying mechanism and the role of surface wettability remain poorly understood. Here, we employ molecular simulations to study and characterize this phenomenon, which we call acoustothermal nucleation. We observe that nanobubbles can nucleate on both hydrophilic and hydrophobic surfaces, and molecular energy balances are used to identify whether these are boiling or cavitation events. We rationalize the nucleation events by defining a physics-based energy balance, which matches our simulation results. To characterize the interplay between the acoustic parameters, surface wettability, and nucleation mechanism, we produce a regime map of nanoscopic nucleation events that connects observed nanoscale results to macroscopic experiments. This work provides insights to better design a range of industrial processes and clinical procedures such as surface treatments, mass spectroscopy, and selective cell destruction.

A decision support scheme for beta thalassemia and HbE carrier screening.

The most effective way to combat ß-thalassemias is to prevent the birth of children with thalassemia major. Therefore, a cost-effective screening method is essential to identify ß-thalassemia traits (BTT) and differentiate normal individuals from carriers. We considered five hematological parameters to formulate two separate scoring mechanisms, one for BTT detection, and another for joint determination of hemoglobin E (HbE) trait and BTT by employing decision trees, Naïve Bayes classifier, and Artificial neural network frameworks on data collected from the Postgraduate Institute of Medical Education and Research, Chandigarh, India. We validated both the scores on two different data sets and found 100% sensitivity of both the scores with their respective threshold values. The results revealed the specificity of the screening scores to be 79.25% and 91.74% for BTT and 58.62% and 78.03% for the joint score of HbE and BTT, respectively. A lower Youden's index was measured for the two scores compared to some existing indices. Therefore, the proposed scores can obviate a large portion of the population from expensive high-performance liquid chromatography (HPLC) analysis during the screening of BTT, and joint determination of BTT and HbE, respectively, thereby saving significant resources and cost currently being utilized for screening purpose.

A Randomized Controlled Trial Comparing the Efficacy of a Combination of Rifaximin and Lactulose with Lactulose only in the Treatment of Overt Hepatic Encephalopathy.

Background: Hepatic encephalopathy (HE), or portosystemic encephalopathy, represents a reversible decrease in neurologic function caused by liver disease, and treatment has traditionally been with non-absorbable disaccharides along with antibiotics and supportive measures. The present study was undertaken to evaluate if their combination therapy were superior to the established therapy in management of HE. Methods: Ninety six (96) patients of hepatic encephalopathy were randomly assigned to receive either lactulose and rifaximin in standard dosage or lactulose only and their response to therapy was monitored using standard assessment tools. The statistical analysis was done using Kaplan- Meier methods to estimate the percentage of patients maintaining survival over time. Results: The patients who were on lactulose and placebo revealed to have lower mortality than those on lactulose and rifaximin. Also, improvement in neurological status was of Grade 1 or more was more in patients on lactulose and placebo when compared to those on lactulose and rifaximin. Although survival analysis revealed no statistical difference between two groups, the mean survival in the placebo group was higher. Conclusions: The present study reveals that improvement in neurological status of the group treated with lactulose only was that of a higher percentage than that of the group being treated with lactulose and rifaximin, which reiterates the recommendation that lactulose be used as a first line therapy in overt hepatic encephalopathy (OHE). Also the outcome was better in patients who had a lower grade of encephalopathy on admission.

Isolated third nerve palsy: a rare neurological presentation of Burkitt's lymphoma.

Lymphoma patient presenting with isolated third nerve palsy is relatively rare, and diagnosis of underlying disease may be challenging. Until this date, less than 20 cases have been described in the literature. This is the case of a 3-year-old boy who presented to neurologist with ptosis of left eye for 8 days. On examination, abdominal mass was detected, and the child was referred to paediatric surgery department. Laparotomy and excision of the mass was done. Histopathology and immunohistochemistry of the mass confirmed it to be a case of Burkitt's lymphoma. At this point, the patient was referred to haematology department. Contrast-enhanced CT brain showed infiltration around left cavernous sinus. Patient was treated with two cycles of R-CODOX-M/R-IVAC. Ptosis improved completely within few days of starting chemotherapy. Follow-up positron emission tomography CT scan done after the second cycle of chemotherapy revealed no metabolically active disease.

Thyroid abscess in case of Pre B acute lymphoblastic leukaemia: a rare presentation.

Thyroid abscess is a very rare clinical condition. It usually occurs in immunocompromised individuals or those with underlying malignancy. We report a case of multiple thyroid abscesses in the patient with Pre B acute lymphoblastic leukaemia which developed secondary to hematogenous spread from pyomyositis of right calf muscle. The patient developed sepsis-associated disseminated intravascular coagulation, which got resolved after thyroidectomy. He became afebrile after surgical intervention. Unfortunately, all the cultures were negative. Since there are few case series and reports, there are no clear guidelines for management of thyroid abscess. We conclude that though rare, thyroid abscess may be the cause of persistent fever in immunocompromised patients.

Nutrient adequacy and its correlation in a sub-Himalayan region of West Bengal, India.

INTRODUCTION: Nutrient adequacy is the level of intake of an essential nutrient in relation to the nutrient requirement for adequate health, which is expressed as the percentage of recommended dietary allowance. To develop an effective nationwide preventive program to combat malnutrition, it is necessary not only to assess the nature and magnitude of the problem of nutrient inadequacy but to identify factors affecting it especially at the household level. OBJECTIVE: To estimate the prevalence of nutrient adequacy in a sample of households in a rural area of Darjeeling district and to find out the factors associated with nutrient adequacy. MATERIALS AND METHODS: A community-based cross-sectional study was carried out from January 2014 to December 2014 in 821 households of Darjeeling district, India. The major dependent variable used in this study was the mean nutrient adequacy ratio of a household and the independent variables were number of family members, number of under-five children in the family, literacy of head of the family, literacy of the wife of the head of the family, income of the family, and percentage expenditure on food. RESULTS: The prevalence of nutrient adequate households was found to be 35.3% among the study households. It was observed that the percentage expenditure on food had the highest contribution toward nutrient adequacy, followed by number of under-five children in the family and literacy of the wife of the head of the family. Undernutrition was found to be prevalent in 56.6% of the households. CONCLUSION: Majority of the study population had a diet less than the required amount and expectedly, undernutrition was also present in huge proportions.

Job Satisfaction among Doctors of a Government Medical College and Hospital of Eastern India.

BACKGROUND: Job satisfaction expresses the extent of congruence between an individual’s expectation of the job and the reward that the job provides.Job satisfaction among doctors is an issue that is of utmost importance because offactors like patient relationships and time pressures associated with managed care. The current study was done to determine the level of job satisfaction in doctors posted in a tertiary care hospital of eastern India and to find out the factors associated with it. MATERIALS AND METHODS: A descriptive cross sectional study was conducted among 255 doctors posted in a tertiary care hospital of eastern India. Data werecollected using a self-reported questionnaire consisting of 49 items addressing the seven domains of job satisfaction, where higher values indicated higher level of satisfaction. The average scores of items were computed to construct factor scores for each individual. Two stage cluster analysis was performed to get the proportion of satisfied doctors and binary logistic regression was used for comparison of predictors of job satisfaction. RESULTS: The proportion of job satisfaction was found to be 59.6% and the most important factor was found to be working space. On adjustment, the odds of being satisfied were found to be higher in the older age groups, among males, doctors posted in preclinical or paraclinical departments and those staying in present setting for 5 years or more. CONCLUSION: More than half of the doctors were found to be satisfied with their job which can help the policy makers to make necessary strategies to increase the level of satisfaction of the employees. .

Perceived HIV Related Stigma among Patients Attending ART Center of a Tertiary Care Center in Rural West Bengal, India.

INTRODUCTION: Despite the advent of modern technologies, India is still grappling with the HIV/AIDS pandemic. Stigma is one of the key aspects which can interfere with HIV test-seeking behaviour, care-seeking behaviour upon diagnosis, quality of care given to HIV-positive patients and perception and treatment of People Living with HIV/AIDS (PLHA) by communities, families, and partners. AIM: To determine the perceived stigma associated with HIV/AIDS and its correlates among PLHAs attending the Anti Retroviral Therapy (ART) centre of North Bengal Medical College, Darjeeling, West Bengal, India. MATERIALS AND METHODS: An observational cross-sectional study was conducted over a period of four months among 454 patients aged ≥18years attending ART centre of North Bengal Medical College. Perceived stigma among the study subjects were assessed using a face and content validated version of Berger's HIV stigma scale. Linear regression analysis was used for statistical analysis of the predictors of perceived stigma. Data were analysed using SPSS version 16 software. RESULTS: The majority of the study population had moderate to low stigma. Regression analysis showed that being on treatment with ART had the highest contribution towards stigma followed by gender and HIV serostatus of the patients. CONCLUSION: The patients attending ART centre of North Bengal Medical College had moderate to low level of stigma. In absence of any efficacious stigma reduction programs in this region, more work needs to be done to assist PLHA in coping with stigma.

Preoperative Ultrasound Guided Fine Needle Aspiration Cytology of Ovarian Lesions- Is It a Rapid and Effective Diagnostic Modality?

INTRODUCTION: The deep seated ovarian lesions unapproachable by unguided aspiration cytology were easily done under ultrasound guidance. It gave a before hand cytological diagnosis of the lesion to the surgeon determining the modality of treatment for the patient. AIM: To find the diagnostic accuracy of the method of ultrasound guided cytological assessment of ovarian lesion. MATERIALS AND METHODS: The study was conducted as a prospective observational study over a period of one year, in hospital setting, where ultrasound guided fine needle aspiration had been used to aspirate ovarian lesions, giving a rapid cytological diagnosis. In 43 sample cases, aspiration of fluid done from ovarian lesions were followed by cyto-centrifugation and staining by May-Grunwald-Giemsa (MGG) and Papanicolaou (Pap) stain providing a cytological opinion regarding benign/malignant nature of the lesion and further categorization. Later the cytological diagnosis was compared with final histopathological diagnosis, taking it as a gold standard. RESULTS: The overall sensitivity, specificity, and diagnostic accuracy of ultrasound guided aspiration and cytological analysis were high, 96%, 76.92% and 89.47% respectively as calculated by comparing the cytological diagnosis with histological diagnosis, taking it as gold standard. CONCLUSION: This method has evolved as a highly sensitive, rapid, simple and effective modality for screening and as well as accurate preoperative diagnosis of ovarian lesions.

A clinicopathological study of peripheral lymph nodes in HIV-infected patients with special reference to CD4+ T-cell counts: Experience from a tertiary care institution in Darjeeling (India).

BACKGROUND: HIV/AIDS is a major health burden worldwide. India bears the third highest HIV-patients load globally. In the Darjeeling district, HIV-prevalence is >1% with very little known about the profile of HIV-lymphadenopathy. The aim of this study was to identify the different causes of peripheral lymphadenopathy among HIV-infected patients in this region, correlate them with CD4+ T-cell counts and formulate some common clinico-haematological parameters as potential predictors of CD4+ T-cell count. METHODS: In the present study, 76 cases were evaluated. Fine Needle Aspiration Cytology (FNAC) was performed as an out-patient procedure in the Department of Pathology. Smears were stained routinely with Haematoxylin-Eosin and Leishman stains. ZN stains were done when indicated by the cytological findings. Immediate CD4+ T-cell count was obtained by referring the patients to the Anti-retroviral therapy centre. RESULTS: Cytological diagnoses included tuberculosis (82.9%), reactive hyperplasia (6.6%), nonspecific granulomatous lesions (3.9%), non-Hodgkin lymphoma (2.6%), histoplasmosis (2.6%) and simultaneous filariasis with toxoplasmosis (1.3%). Statistically, the opportunistic infections and lymphomas significantly concurred with a CD4+ T-cell count <350/µl. Likewise, the number of enlarged lymph nodes and absolute lymphocyte count (ALC) were found to be useful predictors of CD4+ T-cell counts. CONCLUSIONS: Lymph node cytology in HIV-infected patients is essential to identify opportunistic infections from neoplastic lesions and; to enable therapeutic strategies. Correlation of lesions with mean CD4+ T-cell count predicts personal immunity, stage of disease and disease activity. Furthermore, enlarged lymph node numbers and ALC can be surrogate markers of CD4+ T-cell count for monitoring the severity of the immune suppression in under-resourced countries like India.

A Cross-sectional Assessment of Risk Factors of Non-Communicable Diseases in a Sub-Himalayan Region of West Bengal, India Using who Steps Approach.

BACKGROUND: Non-communicable diseases (NCDs), principally cardiovascular diseases, cancer, chronic respiratory diseases, and diabetes are the leading causes of death and disability globally. The basic element of NCD prevention is the identification of the common risk factors and their prevention and control. OBJECTIVE: To determine the prevalence of risk factors for non-communicable diseases, in Siliguri city of West Bengal, India using WHO Steps approach. METHODS: Between April 2012 to July 2012, 779 adults of 18-64 years from Siliguri city were chosen by 30-cluster sampling. They were interviewed and measurements and laboratory tests were done. RESULTS: The prevalence of behavioural risk factors like tobacco use, alcohol, unhealthy diet was 57.5%, 12.5%, 50.87% and 60.4%, respectively while that of biological risk factors like overweight, abdominal obesity and hypertension was 29.8%, 20.2% and 17.8%, respectively. The prevalence of biochemical risk categories like diabetes, hypercholesterolemia, hypertriglyceridaemia, low HDL-C was 9.1%, 17.8%, 16.6% and 67.5%, respectively. CONCLUSIONS: A high prevalence of risk factors for non-communicable diseases was found in Siliguri city which emphasizes the need of interventions to reduce these risk factors.

Retroperitoneal giant ancient schwannoma.

Ancient schwannoma is a rare variant of benign peripheral nerve sheath tumor, often morphologically mimicking malignancy. Retroperitoneum is an uncommon location. We describe one case of giant retroperitoneal ancient schwannoma. Literature concerning this variant is also reviewed. A 65 year old male presented with altered bowel habits. Imaging findings revealed a large heterogeneous mass in the retroperitoneum. The patient was treated with complete excision. Grossly, the tumor was predominantly solid with focal cystic degeneration. Histological examination showed an encapsulated spindle cell tumor with nuclear palisading, very focal nuclear atypia and widespread foam cell infiltration - findings consistent with ancient schwannoma. A diagnosis of ancient schwannoma can be considered for a solid-cystic encapsulated mass in the retroperitoneum. Malignant transformation is very rare. Local recurrence is uncommon following complete excision. The authors have nothing to disclose.

Rare case of chest wall schwannoma with destruction of rib, masquerading as a breast mass.

Schwannomas are slow growing, benign, nerve sheath tumours of Schwann cell origin. They predominantly involve head, neck and flexor surfaces of upper and lower extremities, while the chest wall is an uncommon location for schwannomas. Schwannomas may rarely cause erosion of adjacent bone. We are reporting a very rare case of a chest wall schwannoma with destruction of rib which occurred in a 35-year-old female patient, which initially presented as a breast mass and was radiologically misinterpreted as a malignant soft tissue tumour.

Apert Syndrome.

Apert syndrome is one of the craniosynostosis syndromes which, due to its association with other skeletal anomalies, is also known as acrocephalosyndactyly. It is a rare congenital anomaly which stands out from other craniosynostosis due to its characteristic skeletal presentations.