27 research outputs found
Immunogenic Modulations Induced by Prospective Anti-Malarial Herbal Extracts in Murine Model
Keeping in view the ever increasing problem of drug resistance and affordability of the antimalarial drugs by the poor mass, herbal medicines can become an important and alternative sustainable strategy for malaria treatment. Aqueous extracts of three Himalayan herbs― _Equisetum ravense_, _Artemisia vulgaris_ and _Centella asiatica_, with reported antimalarial property were screened for clinical efficacy against a local strain of _Plasmodium vivax_ antigen in murine model. _E. arvense_ extract was consistent in boosting phagocytic activity, nitric oxide generation, acid phosphatase and alkaline phosphatase activities in the peritoneal macrophages. The effectiveness of the rest herbals was discrete. A need for further detailed investigation to evaluate the clinical efficacy of these herbals seems essential
Structural characteristics of HfO under extreme conditions
Pressure induced structural change of HfO was extensively studied up to 10 GPa with diffraction technique using synchrotron X-ray radiation. The experiment drew attention as ambiguities still exist over the monoclinic to orthorhombic evolution of HfO at high pressure condition. Rietveld refinement of the diffraction patterns leads to determination of the detailed structure of HfO at different pressures. The space group of its first orthorhombic phase is confirmed. Density functional calculations were carried out to understand the pressure induced phase transition. High temperature study of this material was also performed up to 1373 K (1100 C) using synchrotron X-ray source for studying suitability of the material in high temperature applications and precise thermal expansion coefficients are reported
Tantalum doping in : orthorhombic phase formation at ambient conditions and change in path of pressure-induced structural evolution
A systematic study of orthorhombic phase formation at ambient conditions beyond a critical concentration of dopant Tantalum (Ta) in HfO is reported. The effect on the path of structural evolution due to Ta doping in HfO was also investigated. Studies on Ta-doped HfO samples and their path of structural evolution under compression have significant implications for materials undergoing -decay. The effect of continual doping due to -decay from geophysical point of view is discussed
Defect engineered d(0) ferromagnetism in tin-doped indium oxide nanostructures and nanocrystalline thin-films
Origin of unexpected defect engineered room-temperature ferromagnetism observed in tin-doped indium oxide (ITO) nanostructures (Nanowires, Nano-combs) and nanocrystalline thin films fabricated by pulsed laser deposition has been investigated. It is found that the ITO nanostructures prepared under argon environment exhibit strongest ferromagnetic signature as compared to that nanocrystalline thin films grown at oxygen. The evidence of singly ionized oxygen vacancy (V-0(+)) defects, obtained from various spectroscopic measurements, suggests that such V-0(+) defects are mainly responsible for the intrinsic ferromagnetic ordering. The exchange interaction of the defects provides extensive opportunity to tune the room-temperature d(0) ferromagnetism and optical properties of ITOs. (C) 2015 AIP Publishing LLC
Three-Ring-Based Thermotropic Mesogens with a Dimethylamino Group: Structural Characterization, Photophysical Properties, and Molecular Order
Thermotropic
liquid crystals exhibiting light-emitting properties
are gaining popularity as functional materials in view of their application
in organic light-emitting diodes. Such mesogens essentially require
active chromophoric moieties in the mesogenic core so that the mutual
light-emitting and liquid crystalline properties can be realized.
In this work, three-ring-core-based mesogens with a terminal dimethylamino
unit are subjected to structural characterization by various techniques.
These mesogens exhibit enantiotropic nematic as well as smectic A
phase with interdigitated layer organization (SmA<sub>d</sub>). This
is a surprising observation because the SmA<sub>d</sub> organization
is commonly observed for calamitic mesogens with terminal polar groups.
Interestingly, the single-crystal structure of the C<sub>6</sub> homologue
indicates antiparallel packing. Furthermore, the photophysical properties
of a representative C<sub>12</sub> mesogen in solution disclose yet
another exciting feature. The steady-state and time-resolved fluorescence
studies indicate negative solvotochromism in solvents with differing
polarity. To obtain greater insight, density functional theory (DFT)-based
highest occupied molecular orbital–lowest unoccupied molecular
orbital studies are carried out which support intramolecular charge-transfer
interactions in this class of mesogens. Additionally, the DFT calculations
also provide the <sup>13</sup>C chemical shifts which are compared
with the solution NMR values for the structural assignment of all
carbons in the core unit. Furthermore, the two-dimensional separated
local field measurements for the C<sub>12</sub> homologue in nematic
and SmA<sub>d</sub> mesophases offer <sup>13</sup>C–<sup>1</sup>H dipolar couplings from which the molecular order is determined
to be 0.59 and 0.70, respectively
Antibody Response to SARS-CoV-2 among COVID-19 Confirmed Cases and Correlates with Neutralizing Assay in a Subgroup of Patients in Delhi National Capital Region, India
Background: The plaque reduction neutralization test (PRNT) is the gold standard to detect the neutralizing capacity of serum antibodies. Neutralizing antibodies confer protection against further infection. The present study measured the antibody level against SARS-CoV-2 among laboratory-confirmed COVID-19 cases and evaluated whether the presence of anti-SARS-CoV-2 antibodies indicates virus neutralizing capacity. Methods: One hundred COVID-19 confirmed cases were recruited. Their sociodemographic details and history of COVID-19 vaccination, contact with positive COVID-19 cases, and symptoms were ascertained using a self-developed semi-structured interview schedule. Serum samples of the participants were collected within three months from the date of the positive report of COVID-19. The presence of anti-SARS-CoV-2 antibodies (IgA, IgG and IgM antibodies), receptor binding domain antibodies (anti-RBD), and neutralizing antibodies were measured. Findings: Almost all the participants had anti-SARS-CoV-2 antibodies (IgA, IgG and IgM) (99%) and anti-RBD IgG antibodies (97%). However, only 69% had neutralizing antibodies against SARS-CoV-2. Anti-RBD antibody levels were significantly higher among participants having neutralizing antibodies compared with those who did not. Interpretation: The present study highlights that the presence of antibodies against SARS-CoV-2, or the presence of anti-RBD antibodies does not necessarily imply the presence of neutralizing antibodies