84 research outputs found

    Development and Validation of New RP-HPLC Method for Simultaneous Estimation of Amlodipine Besylate and Valsartan in Tablet Formulations.

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    Combination therapy in the treatment of hypertension as an appropriate treatment option is receiving boarder acceptance amongst the clinical community. Mono therapy is often not sufficient to normalize blood pressure since the goal of treatment is to normalize both systolic and diastolic blood pressure. A hypertension treatment guideline recently issued by the European Society of Hypertension and European Society of Cardiology or, in the Guide to Management of Hypertension 2008 issued by the Australian Heart Foundation recommends the combination therapy. It is proposed that these double combination tablets will be indicated as a substitution therapy in patients (i.e. patients are not to be started on this combination therapy) for the treatment of hypertension. As a replacement therapy in patients whose blood pressure is a dequately controlled on amlodipine and valsartan used as individual or combination therapiesMore rapid, precise, specific, sensitive, economic and reproducible gradient reverse phase HPLC method was developed and validated for simultaneous determination of amlodipine besylate and valsartan tablets. The method was validated for specificity, linearity, and precision as per ICH guidelines. The RP-HPLC method for AMBL and VAL detector wave length is 237 nm, the beer’s law was obeyed in the concentration of 100 ppm of AMBL and 128 ppm of VAL and retention time found to be 5.06 and 8.28 min respectively. A new method was developed for the quantification of AMBL and VAL in combined tablet formulation. This method seems to obey the validation parameters and cost effective. This method can be routinely employed for the analysis of this combination. The reason behind selection of two different categories of antihypertensive drugs was also justified properly because of synergistic effect on lowering of blood pressure and reduction of side effects of one drug by another. Side effects of the individual drugs can be mitigated by using a complementary agent rather than increasing the dose of a single agent

    Tropical convective cloud characterization using ground-based microwave radiometric observations

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    Characterization of the microphysical and thermodynamical properties of convective events over the tropical coastal station Thiruvananthapuram (TVM) has been carried out based on multiyear microwave radiometer profiler observations. The analyses have been extended to develop a methodology to identify convective events, which is based on the radiometric brightness temperature (Tb) difference threshold, at 30 and 22.23 GHz channels, and the results are compared with reflectivity and rainfall intensity deduced from concurrent and collocated disdrometer measurements. Eighty-four of such convections were identified using the aforementioned methodology over the station during 2010-2013, i.e., both for pre- and post-Indian summer monsoon months, and further evaluated by computing their stability indexes. The occurrence of convective systems peaks in the afternoon and early-morning hours with genesis, respectively, over the land and the sea

    Remote sensing data acquisition, platforms and sensor requirements

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    Although data available from various earth observation systems have been routinely used in many resource applications, however there have been gaps, and data needs of applications at different levels of details have not been met. There is a growing demand for availability of data at higher repetivity, at higher spatial resolution, in more and narrower spectral bands etc. Some of the thrust areas of applications particularly in the Indian context are; - Management of natural resources to ensure sustainable increase in agricultural production, - Study the state of the environment, its monitoring and assessment of the impact of. various development actions on the environment, - Updating and generation of large scale topographical maps. - Exploration/exploitation of marine and mineral resources and - Operational meteorology and studying various land and oceanic processes to understand/predict global climate changes. Each of these thrust area of application has many components, related to basic resource areas such as agriculture, forestry, water resources, minerals, marine resources etc. and the field of cartography. Observational requirements for major applications have been summarized as under. Monitoring vegetation health from space remains the most important observational parameter with applications, in agriculture, forestry, environment, hydrology etc. Vegetation extent, quantity and temporal changes are the three main requirements which are not fully realized with RS data available. Vegetation productivity, forest biomass, canopy moisture status, canopy biogeochemistry are some examples. Crop production forecasting is an important application area. Remotely sensed data has been used for identification of crops and their acreage estimation. Fragmented holdings, large spread in crop calendars and different management practices continue to pose a challenge lo remote sensing. Remotely sensed data at much higher spatial resolution than hitherto available as well as at greater repetivity are required to meet this need. Non-availability of cloud-free data in the kharif season is one of the serious problems in operational use of remote sensing for crop inventory. Synthetic aperture radar data al X & Ku bands is necessary to meet this demand. Nutrient stress/disease detection requires observations in narrow spectral bands. In case of forestry applications, multispectral data at high spatial resolution of the order of 5 to 10 metres is required to make working plans at forest compartment level. Observations from space for deriving tree height are required for volume estimation. Observations in the middle infrared region would greatly enhance capability of satellite remote sensing in forest fire detection. Temporal, spatial and spectral observational requirements in various applications on vegetation viewing are diverse, as they address processes at different spatial and time scales. Hence, it would be worthwhile to address this issue in three broad categories. a) Full coverage, moderate spatial resolution with high repetivity (drought, large scale deforestation, forest phenology....). b) Full coverage, moderate to high spatial resolution and high repetivity (crop forecasting, vegetation productivity). c) Selected viewing at high spatial resolution, moderate to high repetivity and with new dimensions to imaging (narrow spectral bands, different viewing angles). A host of agrometeorological parameters are needed to be measured from space for their effective use in development of yield models. Estimation of root-zone soil moisture is an important area requiring radar measurements from space. Surface meteorological observations from space at the desired spatial and temporal distributions has not developed because of heavy demands placed on the sensor as well as analytical operational models. Agrometeorology not only provides quantitative inputs to other applications such as crop forecasting, hydrological models but also could be used for farmer advisory services by local bodies. Mineral exploration requires information on geological structures, geomorphology and lithology. Surface manifestation over localized regions requires large scale mapping while the lithology can be deciphered from specific narrow bands in visible. NIR, MIR and TIR regions. Sensors identified for mapping/cartography in conjunction with imaging spectrometer would seem to cover requirements of this application. Narrow spectral bands in the short regions which provide diagnostics of relevant geological phenomenon are necessary for mineral exploration. Thermal inertia measurements help in better discrimination of different rock units. Measurements from synthetic aperture data which would provide information on geological structures and geomorphology are necessary for mineral exploration. The applications related to marine environment fall in three major areas: (i) Ocean colour and productivity, biological resources; (ii) Land-ocean interface, this includes coastal landforms, bathymetry, littoral transport processes, etc. and; (iii) Physical oceanography, sea surface temperature, winds, wave spectra, energy and mass exchange between atmosphere and ocean. Measurement of chlorophyll concentration accurately on daily basis, sea surface temperature with an accuracy of 0.5 °K. and information on current patterns arc required for developing better fishery forecast models. Improved spatial resolution data are desirable for studying sediment and other coastal processes. Cartography is another important application area. The major problems encountered in relation to topographic map updation are location and geometric accuracy and information content. Two most important requirements for such an application are high spatial resolution data of 1 to 2 metre and stereo capability to provide vertical resolution of 1 metre. This requirement places stringent demands on the sensor specifications, geometric processing, platform stability and automated digital cartography. The requirements for the future earth observation systems based on different application needs can be summarized as follows: • Moderate spatial resolution (l50-300m), high repetivity (2 Days), minimum set of spectral bands (VIS, NIR, MIR. TIR) full coverage. • Moderate to high spatial resolution (20-40m), high repetivity (4-6 Days), spectral bands (VIS, MR, MIR, TIR) full coverage. • High spatial resolution (5-10m) muitispectral data with provision for selecting specific narrow bands (VIS, N1R. MIR), viewing from different angles. • Synthetic aperture radar operating in at least two frequencies (C, X, Ku), two incidence angles/polarizations, moderate to high spatial resolution (20-40m), high repetivity (4-6 Days). • Very high spatial resolution (1-2m) data in panchromatic band to provide terrain details at cadastral level (1:10,000). • Stereo capability (1-2m height resolution) to help planning/execution of development plans. • Moderate resolution sensor operating in VIS, NIR, MIR on a geostationary platform for observations at different sun angles necessary for the development of canopy reflectance inversion models. • Diurnal (at least two i.e. pre-dawn and noon) temperature measurements of the earth surface. • Ocean colour monitor with daily coverage. • Multi-frequency microwave radiometer, scatterometer. altimeter, atmospheric sounder, etc

    The epidemiologic impact and cost-effectiveness of new tuberculosis vaccines on multidrug-resistant tuberculosis in India and China.

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    BACKGROUND: Despite recent advances through the development pipeline, how novel tuberculosis (TB) vaccines might affect rifampicin-resistant and multidrug-resistant tuberculosis (RR/MDR-TB) is unknown. We investigated the epidemiologic impact, cost-effectiveness, and budget impact of hypothetical novel prophylactic prevention of disease TB vaccines on RR/MDR-TB in China and India. METHODS: We constructed a deterministic, compartmental, age-, drug-resistance- and treatment history-stratified dynamic transmission model of tuberculosis. We introduced novel vaccines from 2027, with post- (PSI) or both pre- and post-infection (P&PI) efficacy, conferring 10 years of protection, with 50% efficacy. We measured vaccine cost-effectiveness over 2027-2050 as USD/DALY averted-against 1-times GDP/capita, and two healthcare opportunity cost-based (HCOC), thresholds. We carried out scenario analyses. RESULTS: By 2050, the P&PI vaccine reduced RR/MDR-TB incidence rate by 71% (UI: 69-72) and 72% (UI: 70-74), and the PSI vaccine by 31% (UI: 30-32) and 44% (UI: 42-47) in China and India, respectively. In India, we found both USD 10 P&PI and PSI vaccines cost-effective at the 1-times GDP and upper HCOC thresholds and P&PI vaccines cost-effective at the lower HCOC threshold. In China, both vaccines were cost-effective at the 1-times GDP threshold. P&PI vaccine remained cost-effective at the lower HCOC threshold with 49% probability and PSI vaccines at the upper HCOC threshold with 21% probability. The P&PI vaccine was predicted to avert 0.9 million (UI: 0.8-1.1) and 1.1 million (UI: 0.9-1.4) second-line therapy regimens in China and India between 2027 and 2050, respectively. CONCLUSIONS: Novel TB vaccination is likely to substantially reduce the future burden of RR/MDR-TB, while averting the need for second-line therapy. Vaccination may be cost-effective depending on vaccine characteristics and setting

    New tuberculosis vaccines in India: modelling the potential health and economic impacts of adolescent/adult vaccination with M72/AS01E and BCG-revaccination

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    BACKGROUND: India had an estimated 2.9 million tuberculosis cases and 506 thousand deaths in 2021. Novel vaccines effective in adolescents and adults could reduce this burden. M72/AS01E and BCG-revaccination have recently completed phase IIb trials and estimates of their population-level impact are needed. We estimated the potential health and economic impact of M72/AS01E and BCG-revaccination in India and investigated the impact of variation in vaccine characteristics and delivery strategies. METHODS: We developed an age-stratified compartmental tuberculosis transmission model for India calibrated to country-specific epidemiology. We projected baseline epidemiology to 2050 assuming no-new-vaccine introduction, and M72/AS01E and BCG-revaccination scenarios over 2025-2050 exploring uncertainty in product characteristics (vaccine efficacy, mechanism of effect, infection status required for vaccine efficacy, duration of protection) and implementation (achieved vaccine coverage and ages targeted). We estimated reductions in tuberculosis cases and deaths by each scenario compared to the no-new-vaccine baseline, as well as costs and cost-effectiveness from health-system and societal perspectives. RESULTS: M72/AS01E scenarios were predicted to avert 40% more tuberculosis cases and deaths by 2050 compared to BCG-revaccination scenarios. Cost-effectiveness ratios for M72/AS01E vaccines were around seven times higher than BCG-revaccination, but nearly all scenarios were cost-effective. The estimated average incremental cost was US190millionforM72/AS01EandUS190 million for M72/AS01E and US23 million for BCG-revaccination per year. Sources of uncertainty included whether M72/AS01E was efficacious in uninfected individuals at vaccination, and if BCG-revaccination could prevent disease. CONCLUSIONS: M72/AS01E and BCG-revaccination could be impactful and cost-effective in India. However, there is great uncertainty in impact, especially given the unknowns surrounding the mechanism of effect and infection status required for vaccine efficacy. Greater investment in vaccine development and delivery is needed to resolve these unknowns in vaccine product characteristics

    Photocatalytic behavior of Ba(Sb/Ta)2O6 perovskite for reduction of organic pollutants: Experimental and DFT correlation

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    We have synthesized closely packed hexagonal 2D plates and clustered nanoparticle morphologies of Ba(Sb/Ta)2O6 (BSTO) perovskite via the polymerizable complex method for photocatalytic dye degradation activities. The BSTO crystallized in a hexagonal structure. The presence of Ba2+, Sb5+, Ta5+, and O2− chemical states identified from XPS confirmed the formation of mixed Ba(Sb/Ta)2O6 phase accompanied with a minor amount of TaOx. Furthermore, BSTO showed excellent photocatalytic activity for the degradation of various organic dyes. The kinetic studies revealed 65.9%, 77.3%, 89.8%, and 84.2%, of Crystal Violet (CV), Methylene Blue (MB), Rhodamine blue (RhB), and Methylene Orange (MO), respectively, after irradiation of 180 min without using a cocatalyst. The formation of and OH−surface radicals, which are believed to facilitate the degradation of the dyes, are unveiled through first-principles Density Functional Theory (DFT) calculations and scavenging studies. Our results suggest that BSTO holds promise as an excellent photocatalyst with better degradation efficiency for various organic dyes

    Nations within a nation: variations in epidemiological transition across the states of India, 1990–2016 in the Global Burden of Disease Study

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    18% of the world's population lives in India, and many states of India have populations similar to those of large countries. Action to effectively improve population health in India requires availability of reliable and comprehensive state-level estimates of disease burden and risk factors over time. Such comprehensive estimates have not been available so far for all major diseases and risk factors. Thus, we aimed to estimate the disease burden and risk factors in every state of India as part of the Global Burden of Disease (GBD) Study 2016
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