119 research outputs found
Pre-investment perception of investors’ towards security market in indian context
Purpose: The security market comprises the buy and sell of the securities based on the demand. The security markets instruments comprise debt, equity, hybrid securities, and derivatives.
Theoretical framework:The investors perceive the adoption of the security market as necessary to examine the pre-investment in the security market.
Design/methodology/approach: With the implementation and incorporation of security features, the performance of the security market is improved.
Research, Practical & Social implications:The analysis is based on the Indian security market scenario through data collection from 300 respondents. The data were collected through primary data collection in quantitative and qualitative approaches.
Findings:The examination is based on the evaluation of the framed hypothesis based on the demographic profile of the investors in the security market.
Originality/value: The findings concluded that the risk associated with the security investments was subjected to security risk.
Effect of the Sliding of Stacked Live Loads on the Seismic Response of Structures
Dynamic interaction between sliding live loads and the structure they act on is significant in the seismic analysis and design of the structure. The problem becomes more complex when the live loads are in the form of stacks. This paper presents a numerical model to simulate the dynamic interaction between a primary structure (PS) and a set of stacked bodies lying on it. Individual bodies in the stack were termed as secondary bodies (SBs) in this study. The lowest SB in the stack interacts with the structure through friction. Similar frictional forces also exist between different levels of the stack. This numerical model was verified with a Finite Element model. A parametric study was performed on the seismic response by varying the dynamic properties of the structure and SBs. The energy dissipation is found to be significant due to sliding within the stack. A novel methodology is proposed to calculate a modified structural period (Tnew) of the structure to use in its design. It was found that the Tnew varies significantly with the structural period, mass ratios, and coefficients of friction. Finally, design equations are proposed to calculate the Tnew . Two Indian seismic hazard levels were considered for this study
Natriuretic peptide receptor-C is up-regulated in the intima of advanced carotid artery atherosclerosis
OBJECTIVE: Natriuretic peptide receptor-C (NPR-C/NPR-3) is a cell surface protein involved in vascular remodelling that is up-regulated in atherosclerosis. NPR-C expression has not been well characterized in human carotid artery occlusive lesions. We hypothesized that NPR-C expression correlates with intimal features of vulnerable atherosclerotic carotid artery plaque. METHODS: To test this hypothesis, we evaluated NPR-C expression by immunohistochemistry (IHC) in carotid endarterectomy (CEA) specimens isolated from 18 patients. The grade, location, and co-localization of NPR-C in CEA specimens were evaluated using two tissue analysis techniques. RESULTS: Relative to minimally diseased CEA specimens, we observed avid NPR-C tissue staining in the intima of maximally diseased CEA specimens (65%; p=0.06). Specifically, maximally diseased CEA specimens demonstrated increased NPR-C expression in the superficial intima (61%, p=0.17), and deep intima (138% increase; p=0.05). In the superficial intima, NPR-C expression significantly co-localized with vascular smooth muscle cells (VSMCs) and macrophages. The intensity of NPR-C expression was also higher in the superficial intima plaque shoulder and cap regions, and significantly correlated with atheroma and fibroatheroma vulnerable plaque regions (β=1.04, 95% CI=0.46, 1.64). CONCLUSION: These findings demonstrate significant NPR-C expression in the intima of advanced carotid artery plaques. Furthermore, NPR-C expression was higher in vulnerable carotid plaque intimal regions, and correlate with features of advanced disease. Our findings suggest that NPR-C may serve as a potential biomarker for carotid plaque vulnerability and progression, in patients with advanced carotid artery occlusive disease
HPLC Method for Determination of Rifaximin in Human Plasma Using Tandem Mass Spectrometry Detection
The present study was aimed at developing a simple, sensitive, and specific liquid chromatography–tandem mass spectrometry method for the quantification of rifaximin in human plasma using rifaximin D6 as internal standard. Chromatographic separation was performed on Zorbax SB C18, 4.6 x 75 mm, 3.5 μm column with an isocratic mobile phase composed of 10 mM ammonium formate (pH 4.0) and acetonitrile in the ratio of (20:80 v/v), at a flow-rate of 0.3 mL/min. Rifaximin and rifaximin D6 were detected with proton adducts at m/z 786.4 → 754.4 and 792.5 → 760.5 in multiple reaction monitoring positive mode respectively. The acidified samples were subjected to liquid–liquid extraction using a mixture of methyl t-butyl ether - dichloromethane (75: 25) followed by centrifugation, nitrogen-aided evaporation and reconstitution. The method was validated over a linear concentration range of 20 - 20000 pg/mL with correlation coefficient of more than 0.9995. This method demonstrated intra and inter-day precision within 0.6 - 2.6% and 2.2 - 5.6%, and accuracy within 95.7 - 104.2% and 95.8 - 105.0% for rifaximin, respectively. Rifaximin was found to be stable throughout freeze–thawing cycles, bench top and postoperative stability studies. This method was applied successfully for the analysis of blood samples following oral administration of rifaximin (200 mg) in 17 healthy Indian male human volunteers under fasting conditions.Keywords: Bioequivalence, mass spectrometry, rifaximinEast and Central African Journal of Pharmaceutical Sciences Vol. 13 (2010) 78-8
Simultaneous determination of ezetimibe and simvastatin in rat plasma by stable-isotope dilution LC-ESI–MS/MS and its application to a pharmacokinetic study
AbstractA simple, sensitive and specific liquid chromatography–tandem mass spectrometry method was developed for simultaneous quantification of ezetimibe and simvastatin in rat plasma. The deuterium isotopes: ezetimibe d4 and simvastatin d6 were used as internal standards for ezetimibe and simvastatin, respectively. MS/MS detection involved a switch of electron spray ionization mode from negative to positive at retention time 3.01min. Samples were extracted from plasma by liquid–liquid extraction using tertiary butyl methyl ether. Chromatographic separation was achieved with Agilent Eclipse XBD-C18 column using mobile phase that consisted of a mixture of ammonium acetate (pH4.5; 10mM)–acetonitrile (25:75 v/v). The method was linear and validated over the concentration range of 0.2–40.0ng/mL for simvastatin and 0.05–15.0ng/mL for ezetimibe. The transitions selected were m/z 408.3→271.1 and m/z 412.0→275.10 for ezetimibe and ezetimibe d4, and m/z 419.30→285.20 and m/z 425.40→199.20 for simvastatin and simvastatin d6. Intra- and inter-batch precisions for ezetimibe were 1.6–14.8% and 2.1–13.4%; and for simvastatin 0.94–9.56% and 0.79–12%, respectively. The proposed method was sensitive, selective, precise and accurate for the quantification of ezetimibe and simvastatin simultaneously in rat plasma. The method was successfully applied to a pharmacokinetic study by oral co-administration of ezetimibe and simvastatin in SD rats
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