1,178 research outputs found

    Prevalence of Substance Abuse among Engineering Students

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    The study was initiated with the key objective of examining the prevalence rate of substance abuse among engineering students of a premier engineering institute of India, and also to identify the factors responsible for such behaviour among these students. The objectives also included to identify and propose appropriate methods and solutions through which this type behaviour among engineering students could be countered. The study was undertaken among students of a centrally funded technical institute. Data triangulation method was used by taking data from data sources like engineering students, non-technical students, hostel authorities, security personnel, student counsellor, nearby shopkeepers etc. for better data validity. The study was qualitative in nature. In-depth interviews and daily observation methods were used, to identify the nature of substance abuse among students & to provide proper solutions for those who are highly or moderately addicted to substance. The results of the study show that B.Tech students are more addicted to substance than the M.Tech and Ph.D. students. The main reason for this kind of behaviour is due to excessive freedom from both parents and administration. Use of psychoactive substances also leads to various types of health hazards such as chest pain, decrease in stamina and cough. It also has impact on education. In addition, the lack of any involvement from non-users or passive users against instances of substance abuse leads to a state of more vulnerability and a feeling of isolation among the user base. Some probable solutions recommended to decrease the harmful use of substance abuse among students are - awareness programmes, open house discussions, creation of support groups, in addition to strict rules and regulations regarding use of substance in hostels. Routine meeting with parents may also help to evaluate the changes perceived among the wards as a result timely treatment and support could be made available to students

    Regulatory role of proteasome in determination of platelet life span

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    Limit of platelet life span (8-10 days) is determined by the activity of a putative "internal clock" composed of Bcl-2 family proteins, while role of other molecular players in this process remains obscure. Here, we sought to establish a central role of proteasome in platelet life span regulation. Administration of mice with inhibitors of proteasome peptidase activity induced significant thrombocytopenia. This was associated with enhanced clearance of biotin-labeled platelets from circulation and reduction in average platelet half life from 66 to 37 h. Cells pretreated in vitro with proteasome inhibitors exhibited augmented annexin V binding and drop in mitochondrial transmembrane potential indicative of apoptotic cell death and decreased platelet life span. These cells were preferentially phagocytosed by monocyte-derived macrophages, thus linking proteasome activity with platelet survival. Decisive role of proteasome in this process was underscored from enhanced expression of conformationally active Bax in platelets with attenuated proteasome activity, which was consistent with pro-apoptotic phenotype of these cells. The present study establishes a critical role of proteasome in delimiting platelet life span ostensibly through constitutive elimination of the conformationally active Bax. These findings bear potential implications in clinical settings where proteasome peptidase activities are therapeutically targeted

    Assessment of optical, mechanical and nonlinear properties of potassium acid phthalate single crystal: a potential candidate for optoelectronic applications

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    A good optical quality semi-organic single crystal of Potassium Acid Phthalate (KAP) was harvested from aqueous solution by using slow evaporation solution growth technique (SEST) at ambient condition. The defect free single crystal of KAP was analyzed by different instrumentation techniques, for checking its compatibility for different applications. Its unit cell dimensions and phase purity was examined by powder X-ray diffraction (PXRD) and found that it crystallizes in orthorhombic with non-centrosymmetric in nature. The quality of the grown ingot was assessed by high resolution X-ray diffraction (HRXRD) technique and found that, the crystalline quality is better with less grain boundaries. Its optical properties were scrutinized by UV-vis., photoluminescence (PL) and time resolved photoluminescence (TRPL) measurements respectively. The mechanical stability of the grown crystal was tested by Vickers microhardness method and found that the grown crystal shows indentation size effect (ISE) which was explained using different theoretical models. Its third order nonlinear optical properties were studied by Z-scan measurement by using Ti:Sapphire laser as a source and determined its nonlinear absorption coefficient (beta) and it was found that the KAP crystal is one of the preferable choices for optical limiting applications

    Sirtuin inhibition induces apoptosis-like changes in platelets and thrombocytopenia

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    Sirtuins are evolutionarily conserved NAD+-dependent acetyl-lysine deacetylases that belong to class III type of histone deacetylases. In humans, seven sirtuin isoforms (Sirt1 to Sirt7) have been identified. Sirtinol, a cell permeable lactone ring derived from naphthol, is a dual Sirt1/Sirt2 inhibitor of low potency whereas EX-527 is a potent and selective Sirt1 inhibitor. Here we have demonstrated that Sirt1, Sirt2 and Sirt3 are expressed in enucleate platelets. Both sirtinol or EX-527 induced apoptosis-like changes in platelets as revealed from enhanced annexin V binding, ROS production and drop in mitochondrial transmembrane potential. Above changes were associated with increased phagocytic clearance of the platelets by macrophages. Expression of acetylated p53 and the conformationally active form of Bax were found to be significantly higher in both sirtinol- as well as EX-527-treated platelets, thus implicating p53-Bax axis in apoptosis induced by sirtuin inhibitors. Administration of either sirtinol or EX-527 in mice led to reduction in both platelet count and number of reticulated platelets. Our results, for the first time, implicate sirtuins as a central player in determination of platelet aging. Since sirtuin inhibitors are being evaluated for their anti-tumor activity, this study rekindles attention to potential side effect of sirtuin inhibition in delimiting platelet life span and management of thrombosis

    Investigation of Micro-indentation Hardness of Bi2Te3 Based Composite Thermoelectric Materials

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    We have successfully synthesized Bi0.5Sb1.7Te3+x (x = 0, 0.12, 0.14) composite thermoelectric materials via solid state reaction followed by Spark Plasma Sintering (SPS). The structural characterization of these materials carried out by X-ray diffraction reveals to be composite phase consisting of Bi2Te3-type phase with small amount of Te and Sb phase. The micro-hardness performed on samples Bi0.5Sb1.7Te3+x(x = 0, 0.12, 0.14) reveals the reduction of VHN with increasing Te concentration as compared to that of single phase state-of-the-art Bi0.5Sb1.5Te3 thermoelectric materials

    PRIMARY CELL CULTURE OF AEDES ALBOPICTUS MIDGUT CELLS: A PROSPECTIVE MODEL FOR IN VITRO STUDY OF ARBOVIRUSES

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      Objective: Midgut cells play a key role in the propagation of mosquito borne Arboviruses. The existing mosquito cell lines for studying viral pathogenesis are derived either from larvae or from eggs since there is no cell line available from the mosquito midgut. Therefore, to delineate the in situ viral interaction which naturally occurs within the mosquito midgut and represent cellular pathogenesis in human beings, the present work was aimed to develop a primary cell line from the midgut cells of Aedes albopictus.Methods: The midgut cells of A. albopictus were collected, cultured and incubated at 28°C to study the growth after every 24 hrs for 7 days.Result: The primary cell culture showed an increasing growth pattern of columnar cells up to 48 hrs followed by decrease in cell population afterward. However, the number of stem cells increased significantly throughout the study period, and their population outnumbered the columnar cells after 72 hrs. There was no significant change of goblet cells and regenerating cells which were scanty in number throughout the experiment.Conclusion: The present method will help to develop the individual cell lines from mosquito midgut and study the host pathogen interaction in arboviral diseases in future

    Role of Bharatiya Nirdeshak Dravya (BND®) in Development of Indian Reference Materials for Quality Assurance of Products

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    The benchmark of life and quality infrastructure of a nation is mainly dependent on the measurement system of country. The growth of nation in addition to its science & technology is highly influenced by measurement of any physical quantities or policies. The ancient as well as modern sciences predominantly rely on the measurement procedure and its accuracy. One can say that science starts from measurements hence it can be considered as one of the basic aspect of science and its growth. To perform these measurements which are basis of life, simple to sophisticated equipment's are used. The results from these instruments may be not accurate and precise if it is not calibrated. With calibration there is need of comparable measurement to attain the unbroken chain of measurements. Now Certified Reference Materials (CRMs) played critical role in calibration of instrument and to get the comparable measurements which are traceable to national or world-wide standards. The outcomes of sophisticated instruments may be wrong without its calibration. So now it is the time for the scientific and new innovations world to calibrate the sophisticated instruments using these certified reference standards. These CRMs are generally produced and maintained by "National Measurement Institute (NMI)" of the country. In India, Bharatiya Nirdeshak Dravya (BND®) division of National Physical Laboratory (NPL) is continuously working in developing the Indian Reference Materials (IRMs). Now these IRMs can be defined as those substances which are key factors for maintaining a healthy measurement system and to get very precise value. With this these are cost effective IRMs which will improve the quality of products and will help in economic growth of the country. In this article, we are discussing about that measurements which are attached to each steps of our life. But it is necessary that measurement should be accurate and precise and traceable to some true value. CSIR-NPL is continuously focused on the development of IRMs for calibration of instrument, improvement in quality of life, industrial production, global trade and to get accurate and precise measurements

    Growth and Characterization of Single Crystals ofl-Histidine Hydrochloride Monohydrate for Nonlinear Optical Applications

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    In the present study, we have focused on the growth of semi-organic single crystals, as they play a vital role in the generation of a terahertz pulse and its potential applications. The single crystals ofl-histidine hydrochloride monohydrate (LMHCL) were grown by slow evaporation solution growth by using deionized water as a solvent in a controlled atmosphere. Good quality crystals of the required size were obtained within 2 weeks. To estimate the lattice dimensions and get the structural information, powder x-ray diffraction (PXRD) study was performed in which we have found that the crystal belongs to the orthorhombic crystal system with space groupP2(1)2(1)2(1). The functional groups and the corresponding vibrational mode were confirmed using Fourier transform infrared (FTIR) and Raman spectroscopy, respectively. To study the optical properties UV-Vis transmission spectrum and photoluminescence (PL) were recorded. It was observed that the single crystal has a high value of transmission over a long range of wavelength which signifies that the crystal is a good candidate for nonlinear optical (NLO) applications. The UV cut-off wavelength is found to be 236 nm. The grown single crystals were studied by time-domain terahertz spectroscopy (THz-TDS) for photonic applications and the refractive indices were calculated and it is found that the refractive index is nearly equal to 3.4

    Resolving fluorescent species by their brightness and diffusion using correlated photon-counting histograms

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    Fluorescence fluctuation spectroscopy (FFS) refers to techniques that analyze fluctuations in the fluorescence emitted by fluorophores diffusing in a small volume and can be used to distinguish between populations of molecules that exhibit differences in brightness or diffusion. For example, fluorescence correlation spectroscopy (FCS) resolves species through their diffusion by analyzing correlations in the fluorescence over time; photon counting histograms (PCH) and related methods based on moment analysis resolve species through their brightness by analyzing fluctuations in the photon counts. Here we introduce correlated photon counting histograms (cPCH), which uses both types of information to simultaneously resolve fluorescent species by their brightness and diffusion. We define the cPCH distribution by the probability to detect both a particular number of photons at the current time and another number at a later time. FCS and moment analysis are special cases of the moments of the cPCH distribution, and PCH is obtained by summing over the photon counts in either channel. cPCH is inherently a dual channel technique, and the expressions we develop apply to the dual colour case. Using simulations, we demonstrate that two species differing in both their diffusion and brightness can be better resolved with cPCH than with either FCS or PCH. Further, we show that cPCH can be extended both to longer dwell times to improve the signal-to-noise and to the analysis of images. By better exploiting the information available in fluorescence fluctuation spectroscopy, cPCH will be an enabling methodology for quantitative biology
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