426 research outputs found

    Trends in Cardiac Pacemaker Batteries

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    Batteries used in Implantable cardiac pacemakers-present unique challenges to their developers and manufacturers in terms of high levels of safety and reliability. In addition, the batteries must have longevity to avoid frequent replacements. Technological advances in leads/electrodes have reduced energy requirements by two orders of magnitude. Micro-electronics advances sharply reduce internal current drain concurrently decreasing size and increasing functionality, reliability, and longevity. It is reported that about 600,000 pacemakers are implanted each year worldwide and the total number of people with various types of implanted pacemaker has already crossed 3 million. A cardiac pacemaker uses half of its battery power for cardiac stimulation and the other half for housekeeping tasks such as monitoring and data logging. The first implanted cardiac pacemaker used nickel-cadmium rechargeable battery, later on zinc-mercury battery was developed and used which lasted for over 2 years. Lithium iodine battery invented and used by Wilson Greatbatch and his team in 1972 made the real impact to implantable cardiac pacemakers. This battery lasts for about 10 years and even today is the power source for many manufacturers of cardiac pacemakers. This paper briefly reviews various developments of battery technologies since the inception of cardiac pacemaker and presents the alternative to lithium iodine battery for the near future

    A new analytical method for determination of ledipasvir and sofosbuvir in pharmaceutical formulations by HPLC method

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    A simple, Accurate, precise method was developed for the simultaneous estimation of the Sofosbuvir and Ledipasvir in Tablet dosage form. Chromatogram was run through Std Discovery C8 150 x 4.6 mm, 5m. Mobile phase containing Buffer 0.1% OPA: Acetonitrile taken in the ratio 60:40 was pumped through column at a flow rate of 1 ml/min. Buffer used in this method was 0.1% OPA buffer. Temperature was maintained at 30°C. Optimized wavelength selected was 260 nm. Retention time of Sofosbuvir and Ledipasvir were found to be 2.367 min and 3.436 min. %RSD of the Sofosbuvir and Ledipasvir were and found to be 0.6 and 0.5 respectively. %Recovery was obtained as 99.61% and 99.80% for Sofosbuvir and Ledipasvir respectively. LOD, LOQ values obtained from regression equations of Sofosbuvir and Ledipasvir were 0.67, 2.02 and 0.70, 2.12 respectively. Regression equation of Sofosbuvir is y = 4266.x + 7700, and y = 4861.x + 2656.of Ledipasvir. Retention times were decreased and run time was decreased, so the method developed was simple and economical that can be adopted in regular Quality control test in Industries

    Cerimetric Titration of As(III) in Acetic Acid Medium

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    A new analytical method for determination of dolutegravir and rilpivirine in pharmaceutical formulations by RP-HPLC method

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    A simple, rapid, precise, sensitive and reproducible reverse phase high performance liquid chromatography (RP-HPLC) method has been developed for the quantitative analysis of Dolutegravir and Rilpivirine in pharmaceutical dosage form. Chromatographic separation of Dolutegravir and Rilpivirine was achieved on Waters Alliance -2695, by using Luna C18 (250mm x 4.6mm, 5µm) column and the mobile phase containing 0.1% OPA & ACN in the ratio of 50:50 v/v. The flow rate was 1.0 ml/min, detection was carried out by absorption at 245 nm using a photodiode array detector at ambient temperature. The number of theoretical plates and tailing factor for Dolutegravir and Rilpivirine were NLT 2000 and should not more than 2 respectively. The linearity of the method was excellent over the concentration range 10-150 µg/ml and 5-75 µg/ml for Dolutegravir and Rilpivirine respectively. The correlation coefficient was 0.999. % Relative standard deviation of peak areas of all measurements always less than 2.0. The proposed method was validated according to ICH guidelines. The method was found to be simple, economical, suitable, precise, accurate & robust method for quantitative analysis of Dolutegravir and Rilpivirine study of its stability

    Dexamethasone negatively regulates phenobarbitone-activated transcription but synergistically enhances cytoplasmic levels of cytochrome P-450b/e messenger RNA

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    Dexamethasone has a potentiating effect on phenobarbitone mediated induction of cytochrome P-450b + e mRNAs in adult rat liver. However, the glucocorticoid inhibits phenobarbitone-activated transcription of cytochrome P-450b + e mRNAs by 60-70s. This inhibitory effect is evident in run-off transcription of the endogenous genes as well as in the transcription of an added cloned gene fragment. Dexamethasone inhibits the phenobarbitone-mediated increase in the binding of a transcription factor(s) to the upstream region of the gene as evidenced by gel retardation and Southwestern blot analysis. The glucocorticoid does not stabilize the phenobarbitone-induced polyribosomal cytochrome P-450b + e mRNAs but appears to stabilize the nuclear transcripts. It is proposed that a negative element may mediate the action of dexamethasone at the level of nuclear transcription and stabilization of the nuclear transcript may account for the potentiating effect of the glucocorticoid on phenobarbitone-mediated increase in cytochrome P-450b + e mRNAs in the cytoplasm of the adult rat liver. However, the cytochrome P-450b protein levels are slightly lower in phenobarbitone+dexamethasone treatment than in phenobarbitone-treated liver microsomes

    Studies on the extraction and characterization of thermostable a-amylase from pericarp of Borassus indica

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    Thermostable a-amylase was extracted and characterized from the fruits (pericarp) of Borassus indica. Analysis on the influence of various physico-chemical parameters on the extracted enzyme revealed a Vmax of 0.793 and a Km of 0.022. The optimum temperature was found to be 370C at pH 4.5. The stability studies on enzyme activity envisaged that the enzyme is stable up to 800C and retained its activity over a wide range of pH (4.0 – 8.5). Significant enhancement in the enzyme activity was observed in the presence of metal ions like Manganese and Strontium and an insignificant decrement in the presence of Sodium ions.African Journal of Biotechnology Vol. 4 (3), pp. 289-291, 200

    First simultaneous lidar observations of sodium layers and VHF radar observations of E-region field-aligned irregularities at the low-latitude station Gadanki

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    Simultaneous observations of atmospheric sodium (Na) made by a resonance lidar and E-region field-alignedirregularities (FAI) made by the Indian MST radar, both located at Gadanki (13.5°N, 79.2°E) and horizontal winds acquired by a SKiYMET meteor radar at Trivandrum (8.5°N, 77°E) are used to investigate the relationship among sodium layer, FAI and neutral winds in the mesosphere and lower thermosphere region. The altitudes and descent rates of higher altitude (~ 95 km) Na layer and FAI agree quite well. The descending structures of the higher altitude Na layer and FAI are found to be closely related to the diurnal tidal phase structure in zonal winds observed over Trivandrum. At lower altitudes, the descent rate of FAI is larger than that of Na layer and zonal tidal phase. These observations support the hypothesis that the metallic ion layers are formed by the zonal wind shear associated with tidal winds and subsequently get neutralized to manifest in the form of descending Na layers. The descending FAI echoing layers are manifestation of the instabilities setting in on the ionization layer. In the present observations, the altitudes of occurrence of Na layer and FAI echoes being low, we surmise that it is quite possible that the FAI echoes are due to the descent of already formed irregularities at higher altitudes

    Assessment Of Socioeconomic Status And Livelihood Index Among Small-Scale Fishermen Along The Kakinada Coast, Andhra Pradesh, India.

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    This present study provides an overview of the socio-economic characteristics and livelihood capitals of small-scale fishermen (SSF) in Kakinada Coast, Andhra Pradesh, India. It highlights key parameters such as age, sex, household structure, occupational status, income, and expenditure. The study also examines the five central capitals that influence the livelihoods of SSF: human, natural, financial, physical, and social capital. The majority of SSF in Kakinada Coast are in the prime working age group (25-54), with fishing being their primary occupation. The average household size is 4.81, with an average of 2.51 male members and 2.30 female members. Male SSF dominate the community, accounting for 96% of respondents, while females make up only 4%. The physical assets of SSF include large and small boats, fishing gears, drying racks, spades, radios, cooking pots, and jars. Access to natural capital, such as land, open water, usable forest, and aquatic resources, is limited for floating fishers. SSF have a limited level of human capital, including knowledge, skills, education, mental health, disease frequency, and access to training. The livelihood assessment index indicates that SSF possess a moderate level of human, financial, physical, natural, and social capital

    Identification of Dominant Air Pollutants Over Hyderabad Using Principal Component Analysis (PCA)

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    The study aims to bring out the interdependence of the air pollutant components through Correlation and Principal Component Analysis (PCA) to identify the sources causing air pollution in Residential, Resident cum Industrial and Industrial areas of Hyderabad. For this purpose, daily data (from 1st January 2018 to 31st December 2020) of air pollutants recorded by Continuous Ambient Air Quality Monitoring Stations (CAAQMS) that includes 15 air pollution-causing components was collected from the Centre Pollution Control Board (CPCB) website. Data from Residential (Hyderabad Central University (HCU)), Residential and Industrial (ICRISAT-Patencheru), and purely Industrial (Pashmylaram) areas were analyzed and it was identified that 5 majorly contributed pollutants at HCU were due to residential activities however, 5 major pollutants at ICRISAT and Pashmylaram were due to vehicular traffic and industry emissions. The purpose of the study was to figure out the sources of air pollutants and their interdependency under different local conditions. The findings of the study may help the policymakers and authorities concerned to implement different strategies and take necessary steps to keep the pollution levels under control
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