68 research outputs found
Evaluation of the effects of photooxidized Echis carinatus venom on learning, memory and stress
Snake venoms are a mixture of complex proteins, which have many physical and pharmacological properties. Photochemical detoxification has been suggested to generate photooxidized Echis carinatus venom product (POECVP). Antigenically-active photooxidized species of Echis carinatus venom could be obtained by exposing the venom to ultraviolet radiation (UVR) in the presence of methylene blue. The aim of the present study was to evaluate the effects of POECVP on learning, memory and stress in rats. Detoxification of the photooxidized venom was evident since the POECVP-treated group had longer survival time than the group of mice treated with Echis carinatus venom product (ECVP) following intraperitoneal and intracerebral injections. Photooxidized Echis carinatus venom product showed antidepressant activity by prolonging sleep onset and shortening the duration of pentobarbitone-induced hypnosis in mice. In single and chronic dose studies with rats, we observed that POECVP significantly decreased the time needed to reach food in T-maze, shortened transfer latency in elevated plus-maze, and decreased immobility time in forced swim test. We concluded that although there is a possibility of employing POECVP in the treatment of depressive and chronic degenerative illnesses as a nonherbal and nonsynthetic alternative for patients not responding to the available therapy, further investigation is still needed
Workforce interventions to improve access to emergency contraception pills: a systematic review of current evidence in low- and middle-income countries and recommendations for improving performance
Science with the Daksha High Energy Transients Mission
We present the science case for the proposed Daksha high energy transients
mission. Daksha will comprise of two satellites covering the entire sky from
1~keV to ~MeV. The primary objectives of the mission are to discover and
characterize electromagnetic counterparts to gravitational wave source; and to
study Gamma Ray Bursts (GRBs). Daksha is a versatile all-sky monitor that can
address a wide variety of science cases. With its broadband spectral response,
high sensitivity, and continuous all-sky coverage, it will discover fainter and
rarer sources than any other existing or proposed mission. Daksha can make key
strides in GRB research with polarization studies, prompt soft spectroscopy,
and fine time-resolved spectral studies. Daksha will provide continuous
monitoring of X-ray pulsars. It will detect magnetar outbursts and high energy
counterparts to Fast Radio Bursts. Using Earth occultation to measure source
fluxes, the two satellites together will obtain daily flux measurements of
bright hard X-ray sources including active galactic nuclei, X-ray binaries, and
slow transients like Novae. Correlation studies between the two satellites can
be used to probe primordial black holes through lensing. Daksha will have a set
of detectors continuously pointing towards the Sun, providing excellent hard
X-ray monitoring data. Closer to home, the high sensitivity and time resolution
of Daksha can be leveraged for the characterization of Terrestrial Gamma-ray
Flashes.Comment: 19 pages, 7 figures. Submitted to ApJ. More details about the mission
at https://www.dakshasat.in
Excitatory effects of Buthus C56 toxin on Drosophila larval neuromuscular junction
Buthus C56 toxin from venom of the Indian red scorpion Mesobuthus tamulus was studied for its effects on spontaneous miniature excitatory junctional potentials (MEJP) on Drosophila larval neuromuscular junctions. C56 toxin was isolated on CM-Cellulose with linear gradient of ammonium acetate buffer, pH 6.0. Toxin purity was determined on SDS slab gel electrophoresis. Effective concentration of C56 toxin was based on contraction paralysis units (CPU) in Drosophila 3rd instar larvae by microinjection (0.1 CPU/ml = 2 x 10-6 g/ml). The toxin-induced excitatory junctional potentials were studied for calcium dependency (0.2 mM to 1.2 mM Ca2+) in Drosophila Ringer. Excitatory junctional potential amplitude was increased with increasing calcium concentration; maximum increase in the frequency at 0.4 mM Ca2+/4 mM Mg2+ Drosophila Ringer. It was suggested that while amplitude of excitatory junctional potentials was increased with concentration, maximum frequency increase at 0.4 mMCa2+/4 mM Mg2+ Drosophila Ringer may be due to augmented Ca2+ influx in 0.4 mM Ca2+, when NMDA receptors were maximally activated in C56 toxin-treated Drosophila larval neuromuscular junction
Sources, distribution and preservation of organic matter in a tropical estuary (Godavari, India)
Major sources and distribution of Organic Matter (OM) were examined in a tropical monsoonal estuary, the Godavari, using content and isotopic signatures in suspended particulate matter and surface sediments during no-discharge period. The lower (<10 km from the mouth) and upper (>10 km) estuaries have shown remarkably different features with reference to the sources, distribution and preservation of OM. The upper estuary is characterized by relatively high content of Particulate Organic Carbon (POC) and chlorophyll-a (Chl-a) and low suspended matter and sediment OC. In contrast, the lower estuary is characterized by relatively low content of particulate OC and Chl-a and high suspended matter and sediment OC. Our data and model results showed that suspended particulate OM is derived predominantly from freshwater phytoplankton in the upper (∼85%) and lower (∼60%) estuaries, with a minor contribution from estuarine phytoplankton (∼25%) and terrestrial C<sub>3</sub> plants (∼10%) in the lower estuary, during the study period. On the other hand, sediment OM in the upper and lower estuaries derived from both autochthonous and allochthonous sources with nearly equal contributions. Although relatively high in situ production was observed in the upper than the lower estuary, relatively low sediment OC was found in the former than the latter region, suggesting that strong influence of preservation conditions rather than surface biological production on OC accumulation in sediments. This is attributed to intense transformation of OM by heterotrophs in the upper than the lower estuary because of prevailing conducive conditions for degradation of OM in the upper estuary during the study period
Stable isotopes of carbon and nitrogen in suspended matter and sediments from the Godavari estuary
Spatial distribution of the carbon and nitrogen content and their isotopic enrichment in suspended matter and sediments were measured in the Godavari estuary to identify the sources and transformation mechanism of organic matter. Significant variability in isotopic distribution was found over the entire length of the Godavari estuary, suggesting multiple sources of organic matter. The mean isotopic ratios (δ<sup>13</sup>C<sub>sed</sub> −25.1 ± 0.9, δ<sup>13</sup>C<sub>sus</sub> −24.9 ± 1, δ<sup>15</sup>N<sub>sed</sub> 8.0 ± 2 and δ<sup>15</sup>N<sub>sus</sub> 6.5 ± 0.9‰) and elemental concentrations (C<sub>sed</sub> 0.45 ± 0.2%, C<sub>sus</sub> 0.9 ± 0.7%, N<sub>sed</sub> 0.07 ± 0.05% and N<sub>sus</sub> 0.16 ± 0.1%) support a predominantly terrigenous source. Significant enrichment in the isotopic ratios of δ<sup>13</sup>C from the upper to lower estuary in both suspended (−27.5 and −24.3‰, respectively) and sedimentary (−26.2 and −24.9‰, respectively) phases indicates a decrease in the influence of terrigeneous material toward the mouth of the estuary. A significant positive relationship exists between the δ<sup>13</sup>C of suspended and sediment, which indicates that these two organic carbon pools are likely coupled in the form of a significant exchange between the two phases. A positive relationship exists between chlorophyll a and suspended organic matter, which may mean that a significant source of organic carbon is the in situ produced phytoplankton. But, applying a simple mixing model to our isotopes, data yielded about 46% as the contribution of the terrestrial source to suspended matter, which may support the excessive heterotrophic activity in the Godavari estuary reported earlier
Prospective study of pattern of invasive fungal infections (IFI) and role of latex agglutination (LA) in galactomannan (GM) and candidamannan (CM) antigen detection in patients presenting with high-risk neutropenic fever (FN): Tata Memorial Hospital experience
Effect of Microgravity on Synthesis of Nano Ceria
Cerium oxide (CeO2) was prepared using a controlled-precipitation method under microgravity at the International Space Station (ISS). For comparison, ceria was also synthesized under normal-gravity conditions (referred as control). The Brunauer-Emmett-Teller (BET) surface area, pore volume and pore size analysis results indicated that the ceria particles grown in space had lower surface area and pore volume compared to the control samples. Furthermore, the space samples had a broader pore size distribution ranging from 30–600 Å, whereas the control samples consisted of pore sizes from 30–50 Å range. Structural information of the ceria particles were obtained using TEM and XRD. Based on the TEM images, it was confirmed that the space samples were predominantly nano-rods, on the other hand, only nano-polyhedra particles were seen in the control ceria samples. The average particle size was larger for ceria samples synthesized in space. XRD results showed higher crystallinity as well as larger mean crystal size for the space samples. The effect of sodium hydroxide concentration on synthesis of ceria was also examined using 1 M and 3 M solutions. It was found that the control samples, prepared in 1 M and 3 M sodium hydroxide solutions, did not show a significant difference between the two. However, when the ceria samples were prepared in a more basic medium (3 M) under microgravity, a decrease in the particle size of the nano-rods and appearances of nano-polyhedra and spheres were observed
The photodynamic action of UV sensitized methylene blue on the venom of Thailand cobra Naja siamensis
- …