829 research outputs found
Neogi_Singh_2022
No full text<p>Data and codes for the paper:</p>
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<p>Neogi, S. & Singh, M.S. (2022). Understanding changes in the tropical circulation under global warming using a cloud resolving model and a conceptual model. J. Climate, in press, doi:10.1175/JCLI-D-21-0854.1.</p>
UV resistance and fire retardant property enhancement of unsaturated polyester composite
No full textPolymer matrix composites are increasingly being used due to their low cost and simple fabrication methods. Polyester resins are amongst the most cost effective and efficient types of resins. But certain drawbacks limit the performance of these resins to be used as structural materials. These limitations include poor fire retardant properties, degradation on exposure to UV radiations and moisture diffusivity. To overcome these drawbacks, certain additives have been used such as aluminium trihydroxide (ATH) and carbon black. ATH serves the purpose of improving the fire retardant properties and carbon black provides UV resistance to the composite. In the present work, the effect of ATH and carbon black, to improve fire resistant properties and UV resistance of unsaturated polyester resin, has been investigated. An estimation of the limited oxygen index, smoke density rating and thermogravimetric analysis of ATH-filled resins has been carried out. Results indicate that the mechanical properties such as tensile strength and tensile modulus can be used to estimate the extent of degradation of carbon-filled resin on exposure to UV radiations. It has been found that even after UV exposure, the mechanical properties of carbon-filled samples do not decrease significantly. These tests have been performed at different loadings of the filler materials. Apart from the extent of loading, the amount of dispersion of the filler in the matrix is also found to influence the final properties of the polymer composite. The appropriate method of dispersion has been developed based on the observations made from the scanning electron microscope images
Neogi_Singh_2022
No full textData and codes for the paper:
Neogi, S. & Singh, M.S. (2022). Understanding changes in the tropical circulation under global warming using a cloud resolving model and a conceptual model. J. Climate, in press, doi:10.1175/JCLI-D-21-0854.1.</p
Global Financial and Economic Crisis: Implications for Trade and Industrial Restructuring in South Asia
No full textThis study investigates the impact of global crisis shocks on India's trade and industry. The authors use panel data modeling and vector autoregression techniques to understand the dynamic effects of global crisis shocks on Indian industry and trade. Changes in trade composition are positively associated with changes in manufacturing composition in India, controlling for other variables. However, there is no strong indication that Indian industry has been severely harmed by the fall in demand in crisis-affected advanced economies such as the United States, the European Union, and Japan, holding other things constant.india trade industry; indian industry; india manufacturing sector; india external trade; global economic crisis
sj-docx-1-car-10.1177_19476035231172152 – Supplemental material for Associations of Changes in Knee Hyaline Cartilage Composition Measured With Dual-Energy Computed Tomography in Gout, Aging and Osteoarthritis
No full textSupplemental material, sj-docx-1-car-10.1177_19476035231172152 for Associations of Changes in Knee Hyaline Cartilage Composition Measured With Dual-Energy Computed Tomography in Gout, Aging and Osteoarthritis by Julie Legrand, Claire Marzin, Tuhina Neogi, Laurène Norberciak, Jean-François Budzik and Tristan Pascart in CARTILAGE</p
Translational genomics of HIV-1 subtype C in India : molecular phylogeny and drug resistance
No full textThis thesis describes the translational genomics of HIV-1subtype C in India from its origin to therapeutic response with the aim to improve our knowledge for better therapeutic and preventive strategies to combat HIV/AIDS. In a systemic approach, we identified the molecular phylogeny of HIV-1 subtypes circulating in India and the time to most recent common ancestors (tMRCA) of predominant HIV-1 subtype C strains. Additionally, this thesis also studied drug resistance mutations in children, adolescents and adults, the role of host factors in evolution of drug resistance, and population dynamics of viremia and viral co-receptor tropism in perinatal transmission. Finally, the long term therapeutic responses on Indian national first-line antiretroviral therapy were also studied.In Paper I, we reported an increase in the HIV-1 recombinant forms in the HIV-1 epidemiology using a robust subtyping methodology. While the study confirmed HIV-1 subtype C as a dominant subtype, its origin was dated back to the early 1970s from a single or few genetically related strains from South Africa, whereafter, it has evolved independently.In Paper II, the lethal hypermutations due to the activity of human apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (hA3G) was significantly associated with antiretroviral therapy (ART) failure in Indian HIV-1 subtype C patients. The presence of M184I and M230I mutations were observed due to the editing of hA3G in the proviral compartment but stop codons were also found in the open reading frames and the same drug resistance mutations were absent in plasma virus. Therefore, it is unlikely that the viral variants which exhibit hypermutated sequences and M184I and/or M230I will mature and expand in vivo and hence are unlikely to have any clinical significance. The high concordance of drug resistance genotyping in the plasma and proviral compartments in therapy-naïve patients, gives weight to the idea of using whole blood for surveillance of drug resistance mutations which precludes logistic challenges of cold chain transport.In Papers III and IV, we identified a substantial proportion of HIV-1 subtype C perinatally-infected older children who had a high burden of plasma viremia but also had high CD4+ T-cell counts. In addition, older children with HIV-1 subtype C infection presented a high prevalence of predicted X4 and R5/X4 tropic strains which indicates that HIV-1 subtype C strains required longer duration of infection and greater disease progression to co-receptor transition from R5- to X4-tropic strains (IV). Our studies also indicate that transmitted drug resistance is low among Indian HIV-1 infected children, adolescents (III) and adults (II).In Paper V, in a longitudinal cohort study, a good long-term response to the Indian national first-line therapy for a median of nearly four years with 2.8% viral failure, indicating the overall success of the Indian ART program. Our study also showed that three immunologically well patients with virological rebound and major viral drug resistance mutations (M184V, K103N and Y181C) during one study visit had undetectable viral load at their next visit. These findings suggest that use of multiple parameters like patients’ immunological (CD4+ T-cell count), virological (viral load) and drug resistance data should all be used to optimize the treatment switch to second line therapy.In conclusion, this translational genomics study enhances our knowledge about the HIV-1 subtype C strains circulating in India which are genetically distinct from prototype African subtype C strains. Considerably more research using appropriate models need to be performed to understand the phenotypic and biological characteristics of these strains to guide efficient disease intervention and management strategies.List of scientific papersI. Neogi U, Bontell I, Shet A, De Costa A, Gupta S, Diwan V, Laishram RS, Wanchu A, Ranga U, Banerjea AC, Sönnerborg A. (2012) Molecular epidemiology of HIV-1 subtypes in India: Origin and evolutionary history of the predominant subtype C. PLoS ONE. 7(6):e39819. https://doi.org/10.1371/journal.pone.0039819 II. Neogi U, Shet A, Sahoo PN, Bontell I, Ekstrand ML, Banerjea AC, Sönnerborg A. (2013) Human APOBEC3G-mediated hypermutation is associated with antiretroviral therapy failure in HIV-1 subtype C-infected individuals. J Int AIDS Soc. 16:18472. https://doi.org/10.7448/IAS.16.1.18472 III. Neogi U, Sahoo PN, De Costa A, Shet A. (2012) High viremia and low level of transmitted drug resistance in anti-retroviral therapy-naïve perinatally-infected children and adolescents with HIV-1 subtype C infection. BMC Infec Dis. Nov 22; 12(1): 317. https://doi.org/10.1186/1471-2334-12-317 IV. Neogi U, Sahoo PN, Arumugam K, Sönnerborg A, De Costa A, Shet A. (2012) Higher prevalence of predicted X4-tropic strains in perinatally- infected older children with HIV-1 subtype C in India. J Acquir Immune Defic Syndr. 59(4): 347-53. https://doi.org/10.1097/QAI.0b013e3182405c7b V. Neogi U, Heylen E, Shet A, Chandy S, Shamsunder R, Sönnerborg A, Ekstrand ML. (2013) Long-term efficacy of first line antiretroviral therapy in Indian HIV-1 infected patients: A longitudinal cohort study. PLoS ONE. 8(1):e55421. https://doi.org/10.1371/journal.pone.0055421 </p
Stable Drop Shapes under Disjoining Pressure: II. Multiplicity and Stability
No full textThe stability of the contact line region as affected by the disjoining pressure has been analyzed by solving the augmented Young-Laplace equation. Because of the results in Part I (Zhang, X., Neogi, P., and Ybarra, R. M., J. Colloid Interface Sci.), we have concentrated on obtaining multiple solutions for the same set of conditions. as many as five solutions were obtained: drops that end in a thin film with uniform thickness and where the film shape oscillates, drops that end with microscopic contact angles, as well as uniform thin films of two different thicknesses. the results of linear stability analysis were used to show that most cases were unstable to infinitesimal disturbances. Only two stable drop shapes for the particular disjoining pressure investigated are stable, a thin film of constant thickness and a thin drop that ends in a film of same thickness. Both multiplicity and stability have been discussed here for the first time and shed considerable light on the role of the attractive and repulsive forces. © 2002 Elsevier Science (USA)
Role of ANO4 in regulation of aldosterone secretion in the zona glomerulosa of the human adrenal gland
No full textBackground: Cell origin of aldosterone-producing adenomas, a major cause of hypertension, is unknown. A less common subtype of these adenomas, composed of cells resembling zona glomerulosa, have mutations in genes ATP1A1 and CACNA1D. To understand whether the adenomas originate from zona glomerulosa, we carried out a microarray analysis comparing transcriptomes of zona glomerulosa, zona fasciculata, and tumour in human adrenal tissue, and investigated the functional role of genes upregulated in the zona glomerulosa. Methods: Using a microarray analysis (Affymetrix, High Wycombe, UK), we compared transcriptomes of zona glomerulosa, zona fasciculata, and tumour obtained by laser capture microdissection of 14 patients with aldestosterone adenomas and seven with phaeochromocytoma. One of the most zona glomerulosa-selective genes was ANO4, a member of the anoctamin family. Subcellular localisation was observed by immunofluorescence microscopy of transfected HEK293 cells. Yellow fluorescent protein-based assay was performed to detect ANO4 activity as a calcium-activated chloride channel. H295R cells were transfected by ANO4 to measure aldosterone and CYP11B2 expression. Findings: Microarray analysis revealed 28 genes that were at least five times overexpressed in zona glomerulosa compared with zona fasciculata. ANO4 was 19·9 times higher in zona glomerulosa than in zona fasciculata (p=6·6 × 10(-24)). Haemagglutinin-tagged ANO4 was localised to the plasma membrane of transfected HEK293 cells. In response to increased intracellular calcium, ANO4-transfected cells triggered a lower flow of iodide than did other anoctamins. ANO4 overexpression in H295R cells increased aldosterone secretion from mean 0·9 pmol/μg protein (SE 0·2) to 1·1 (0·1), whereas CYP11B2 mRNA expression increased five times. Interpretation: We show that ANO4 is one of the most highly expressed genes in zona glomerulosa of the human adrenal gland. When overexpressed in vitro, it increases aldosterone production. Funding: British Heart Foundation
Effect of Ni doping on the magnetic and electronic properties of half heusler Cu1-xNixMnSb alloys
No full textThe effect of Ni-doping on the magnetic and electronic properties of cubic half heusler Cu1-xNixMnSb (x = 0.04, 0.07, 0.1, 0.125) compounds have been investigated both experimentally and theoretically in light of the development of half-metallic ferromagnetism (HMFM) in x = 1, NiMnSb. Our findings reveal that Ni-substitution introduces ferromagnetic (FM) correlations within the parent AFM matrix of CuMnSb. This is followed by the reduction in spin-down density of states (DOS) at the Fermi energy (EF), verified from the gradual suppression of T2-dependency in the low T resistivity variation upon increasing doping content. The ab-initio electronic structure calculations further suggest that the Sb p-holes, produced upon Ni doping, mediate the RKKY-type indirect FM exchange between the distant Mn atoms, and consequently, the spin-down DOS starts to get depleted at the Fermi energy. Further the importance of the Sb p-holes in mediating ferromagnetic (FM) exchange interaction, is illustrated theoretically on Fe-doped Cu1-x FexMnSb systems having identical crystal structure, where appreciable Sb holes stabilizes FM correlations at much lower concentration of Fe
A randomized double-blind placebo-controlled clinical study on the effects of gabapentin premedication on hemodynamic stability during laparoscopic cholecystectomy
No full textBackground: Carbon dioxide pneumoperitoneum for laparoscopic surgery increases arterial pressures, heart rate, and systemic vascular resistance. In this randomized double-blind placebo-controlled clinical study, we investigated the efficacy of gabapentin premedication to provide perioperative hemodynamic stability in patients undergoing laparoscopic cholecystectomy.
Materials and Methods: Sixty patients, of either sex (18-65 years of age) undergoing elective laparoscopic cholecystectomy were randomly allocated to two groups of 30 patients each. Patients of group G received oral gabapentin 900 mg 2 h before induction of anesthesia, while patients in group P received placebo at the same time.
Results: Mean arterial pressure in patients of group G were significantly lower (P < 0.05) after tracheal intubation and pneumoperitoneum and remained lower, as compared to group P, throughout the pneumoperitoneum. Similarly, heart rate in group G was significantly lower (P < 0.05) after tracheal intubation and pneumoperitoneum and remained lower, in comparison to group P, throughout the peumoperitoneum. Intravenous labetalol was required, to control intraoperative hypertension, in 33.3% (10 out of 30) patients in group P. There was no significant difference in the incidence of adverse effects between the two groups.
Conclusion: Gabapentin premedication provided perioperative hemodynamic stability during laparoscopic surgery
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