641 research outputs found

    Characterization of VHF radar observations associated with equatorial Spread F by narrow-band optical measurements

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    International audienceThe VHF radars have been extensively used to investigate the structures and dynamics of equatorial Spread F (ESF) irregularities. However, unambiguous identification of the nature of the structures in terms of plasma depletion or enhancement requires another technique, as the return echo measured by VHF radar is proportional to the square of the electron density fluctuations. In order to address this issue, co-ordinated radar backscatter and thermospheric airglow intensity measurements were carried out during March 2003 from the MST radar site at Gadanki. Temporal variations of 630.0-nm and 777.4-nm emission intensities reveal small-scale ("micro") and large-scale ("macro") variations during the period of observation. The micro variations are absent on non-ESF nights while the macro variations are present on both ESF and non-ESF nights. In addition to the well-known anti-correlation between the base height of the F-region and the nocturnal variation of thermospheric airglow intensities, the variation of the base height of the F-layer, on occasion, is found to manifest as a bottomside wave-like structure, as seen by VHF radar on an ESF night. The micro variations in the airglow intensities are associated with large-scale irregular plasma structures and found to be in correspondence with the "plume" structures obtained by VHF radar. In addition to the commonly observed depletions with upward movement, the observation unequivocally reveals the presence of plasma enhancements which move downwards. The observation of enhancement in 777.4-nm airglow intensity, which is characterized as plasma enhancement, provides an experimental verification of the earlier prediction based on numerical modeling studies

    Evaluation of anti-tumor activity of ethanolic extract of Glycyrrhiza glabra against Ehrlich ascites carcinoma in swiss albino mice

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    Background: Cancer is one of the most life threatening diseases which is in need of newer drug development. The use of plant products with potent antioxidant and cytotoxic activity is upcoming Studies reveal that herbal product have increased efficacy as well as decreased side effects, with this in mind the present study was undertaken to assess the antitumor activity of extracts of Glycyrrhiza glabra (GG) against ehrlich ascites carcinoma in swiss albino mice.Methods: The extracts of roots of GG was collected and acute toxicity study was done following which the antitumor effect of extracts of GG was assessed by change in the body weight, mean survival time (MST), and percentage increased life span (% ILS). MST of each group containing six mice was monitored by recording the mortality daily for 6 weeks and % ILS was calculated. The hematological parameters and biochemical assays were also measured.Results: Extracts of GG showed a significant reduction in % increase in tumor induced body weight of the mice. The % increase in life span was also significant in the higher dose of GG (500 mg/kg). The combination of GG with standard drug cisplatin had better efficacy in terms of % ILS, hematological and biochemical parameters. The results obtained were statistically significant.Conclusions: The antitumor activity studies measuring the viability of cancer cells when exposed to the ethanolic extract of Glycyrrhiza glabra showed a potent cell-killing effect, indicating the presence of anti-cancer principles in the preparation

    Characterizations of the diurnal shapes of OI 630.0 nm dayglow intensity variations: inferences

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    International audienceMeasurements of OI 630.0 nm thermospheric dayglow emission by means of the Dayglow Photometer (DGP) at Mt. Abu (24.6° N, 73.7° E, dip lat 19.09° N), a station under the crest of Equatorial Ionization Anomaly (EIA), reveal day-to-day changes in the shapes of the diurnal profiles of dayglow intensity variations. These shapes have been characterized using the magnetometer data from equatorial and low-latitude stations. Substantial changes have been noticed in the shapes of the dayglow intensity variations between 10:00?15:00 IST (Indian Standard Time) during the days when normal and counter electrojet events are present over the equator. It is found that the width (the time span corresponding to 0.8 times the maximum dayglow intensity) of the diurnal profile has a linear relationship with the integrated electrojet strength. Occasional deviation from this linear relationship is attributed to the presence of substantial mean meridional wind

    Prediction of outcomes in acute exacerbation of COPD with DECAF score and BAP 65 score in a rural population

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    Background: Prognostic research in exacerbations of chronic obstructive pulmonary disease (COPD) requiring hospitalization has been limited and there appears to be little common ground between predictors of mortality in stable disease and during AECOPD. Furthermore, none of the prognostic tools developed in stable disease have been tested on hospitalised patients, and most require clinical measurements not routinely available at hospital admission. This study intends to test dyspnoea, eosinopenia, consolidation, acidemia, and atrial fibrillation (DECAF) and biological assessment profile (BAP) 65 Scores on Indian patients in a tertiary care set up and validate the same to be used as a routine and effective score in predicting the outcome in AECOPD.  Methods: Hospital based prospective observational study was carried out in 100 patients with AECOPD who was present to general medicine. DECAF and BAP-65 Scores were calculated. Data was analyzed using SPSS 22 version software.Results: In our study both DECAF score and BAP‑65 score performed equally well for prediction of need for Mechanical Ventilation. The AUROC for need for Mechanical Ventilation was 0.77 (95% CI=0.67–0.84) for DECAF score and 0.77 (95% CI=0.67–0.85) for BAP‑65 score. The AUROC for prediction of mortality for DECAF score was 0.83 (95% confidence interval [CI]=0.74–0.89) and for BAP‑65 score was 0.79 (95% CI=0.69–0.86).Conclusions: DECAF and BAP-65 are good and also equal in predicting mortality as well as need for mechanical ventilation. Both scores can be easily applicable in AECOPD patients, so that death during hospitalization for AECOPD and need for mechanical ventilation can be minimized.
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