732 research outputs found
Hepatitis C virus infection in patients with oral lichen planus
Background: Lichen planus (LP) is a chronic mucocutaneous disease of uncertain etiology. Recent reports suggest that LP is an extrahepatic manifestation of Hepatitis C infection.Objective: To determine the association of Hepatitis C virus (HCV) infection with oral LP and to study the tests of liver function in patients with oral LP.Study Design: A cross-sectional case-control study was carried out on 25 patients with oral LP and an equal number of controls. The study was conducted in the outpatient department of a dental college for a period of six months between January and June 2008. The sera of the patients and controls were tested for HCV ribonucleic acid (RNA) using reverse transcription primed-polymerase chain reaction and liver function tests (bilirubin, transaminases, and alkaline phosphatase).Results: Of the 25 patients with LP, three (12%) had HCV infection. None of the controls had HCV RNA positivity (P = 0.2347). Oral LP patients had higher serum bilirubin and transaminases when compared with controls (P < 0.05). However, there was no significant difference in alkaline phosphatase. HCV-positive and -negative patients did not differ significantly in liver function tests.Conclusions: An increased prevalence of HCV infection was seen in oral LP patients. Our findings support a possible etiological association between these two diseases
Proposal and Description of a Test System with Wind, Hydro and Fossil Fuel Power Plants for Static Analyses
This article presents and describes a 229 bus test system that includes wind,
hydro and fossil fuel power plants. It represents the Northeast subsystem of
the Brazilian Interconnected Power System (BIPS). The test system supplies a
load of 4.17 GW, being 13% powered by wind farms, which is the current wind
power penetration level of the BIPS. The data comprehends different load levels
based on the typical load behavior and typical capacity factors of wind, hydro
and fossil fuel plants, as well as the capacity of transmission and
sub-transmission lines, transformers, and the adopted structure for the test
system. The data is compiled considering models and operating scenarios of the
BIPS, and allow performing studies of static voltage stability, sensitivity of
voltage stability margin considering the wind farms, and multi-objective
optimization considering market constraints. The results of the simulations
with the test system indicate the consistency of their data structure and its
applicability to different studies of electric power systems.Comment: In proceedings of the 11th Bulk Power Systems Dynamics and Control
Symposium (IREP 2022), July 25-30, 2022, Banff, Canad
Menstrual pattern amongst adolescent girls: a cross sectional study from Raichur, Karnataka
Background: Menstrual disorders in adolescent age are quite different than in adult women, both for diagnostic and therapeutic management. We need to take into account the problems in normal initiation of menarche, hematological problems, general endocrine problems, and fragile emotional status at this tender age. The objective of the study was to study the patterns of menstrual disorders in adolescent girls.Methods: Cross sectional observational study was carried out in 200 adolescent girls, aged 12 to 19 years, among the students of S.R.P.S PU college and the district government Girls’ school in Raichur during the period of January 2017 to December 2017. A pre-structured questionnaire was used and data was analysed using Statistical package for social sciences (SPSS) 23.0 version.Results: Majority of the girls in our study were from 17-18 years age group (55%). The mean age of menarche was 13.2±0.9 years. Cycle length of 35 days cycle length. Majority had normal cycle length. Dysmenorrhea was found in 84 (42%) students. Premenstrual symptoms like tiredness were noted in 14 (7%) of cases, pain in the legs in 10 (5%), irritability in 8 (4%), lack of interest in work and play in 7 (3.5%), low back pain in 6 (3%), low/depressed mood in 6 (3%), anger in 4 (2%), anxiety in 4 (2%), difficulty in concentrating in 2 (1%), nausea\vomiting were noted in 2 (1%).Conclusions: Prevalence of dysmenorrhea was 42%. Premenstrual symptoms like tiredness were noted in majority of the girls 7%, pain in the legs in 5%, irritability in 4%
A BATTERY ENERGY STORAGE SYSTEM WITH CONTROLLED REDUCED-RATING DYNAMIC VOLTAGE RESTORER
In this paper, different voltage injection schemes for dynamic voltage restorers (DVRs) are analyzed with particular focus on a new method used to minimize the rating of the voltage source converter (VSC) used in DVR. A new control technique is proposed to control the capacitor-supported DVR. The control of a DVR is demonstrated with a reduced-rating VSC. The reference load voltage is estimated using the unit vectors. The synchronous reference frame theory is used for the conversion of voltages from rotating vectors to the stationary frame. The compensation of the voltage sag, swell, and harmonics is demonstrated using a reduced-rating DVR. Power quality problems such as transients, sags, swells, and other distortions to the sinusoidal waveform of the supply voltage affect the performance of these equipment pieces. Technologies such as custom power devices are emerged to provide protection against power quality problems. Custom power devices are mainly of three categories such as series-connected compensators known as dynamic voltage restorers (DVRs), shunt-connected compensators such as distribution static compensators, and a combination of series and shunt-connected compensators known as unified power quality conditioner. The DVR can regulate the load voltage from the problems such as sag, swell, and harmonics in the supply voltages. Hence, it can protect the critical consumer loads from tripping and consequent losses. The custom power devices are developed and installed at consumer point to meet the power quality standards such as IEEE-51
NOVEL TECHNIQUES TO PREPARE SOLID DISPERSIONS TO IMPROVE SOLUBILITY OF BOSENTAN
ABSTRACT
Objective: Bosentan presents challenges with regard to low and variable oral bioavailability due to its poor aqueous solubility and poor dissolution in gastric fluid. Solid dispersion has been used as the solubility enhancement technique due to its ability to develop suitable system with improved solubility and dissolution rate. Methods: Solid dispersions of bosentan were prepared by using novel techniques like solvent controlled coprecipitation, fusion and nanoprecipitation. Polymers with different ionic characteristics like Eudragit® EPO (cationic), Eudragit® L 100 55 (anionic) and Povidone K 30 (non-ionic) were employed at three different ratios of 1:1, 1:2 and 1:3 to prepare the solid dispersions of weakly basic bosentan. Dissolution study in buffers corresponding to different physiologically relevant pH was performed to understand the effectiveness of the technique and effect of the polymer. Additionally, samples were subjected for X-ray powder diffraction study to understand the nature of the drug in solid state in the solid dispersion systems. Results: It was observed that irrespective of the pH of the dissolution media, the dissolution rate of the solid dispersions of BOS prepared with Eudragit® L 100 55 are higher than that of pure drug and the solid dispersions prepared with the other polymers i.e. Eudragit® EPO and Povidone K 30, which is attributed to the weakly basic nature of bosentan. The diffractograms show decrease in the crystallinity of bosentan in the solid dispersions. Conclusion: The combination of solid dispersion technology with supersaturable systems appears to hold promise for improving dissolution and bioavailability of poorly soluble drugs. The selection of polymers that can inhibit crystallization of the drug in a supersaturated state becomes the key factor for an effective formulation. The present work is an attempt in this direction.
KEYWORDS: Solid Dispersion, Super Saturable systems, Insoluble drugs
Lithograph-moulded poly-L-co-D,L lactide porous membranes for osteoblastic culture
Pore size, shape, wall morphology, porosity, and interconnectivity are important characteristics of the scaffolds. Lithography is a manufacturing technique that allows the production of tridimensional scaffolds with a controllable and reproducible inner architecture. The aim of this study was to use lithography to create a poly-L-co-D,L lactide (PLDLA) scaffold with symmetrical pore size and distribution, and to evaluate its biocompatibility with osteoblasts in vitro. Lithographic moulds were used to produce porous PLDLA membranes by a casting procedure. Osteoblasts were removed from calvarial bones and seeded onto porous and smooth PLDLA membranes after which cell viability and adhesion assays, cytochemical analysis and scanning electron microscopy were used to characterize the cells. Cell viability and adhesion assays, cytochemical analysis, and scanning electron microscopy were carried out. Cell viability was similar on porous and smooth PLDLA membranes but higher than on a polystyrene substrate (positive control). Although osteoblasts adhered to the surface of all the materials tested, cell adhesion to lithographed PLDLA was greater than to smooth PLDLA membranes. In conclusion, osteoblasts interacted well with PLDLA membranes, as shown by the viability and adhesion assays and by the enhanced collagen production17171
GREEN SYNTHESIS OF NANOSTRUCTURED ZINC PARTICLES USING AQUEOUS LEAF EXTRACT OF SCHREBERA SWIETENIOIDES ROXB. AND THEIR CATALYTIC APPLICATION IN DEGRADATION OF METHYL ORANGE, CRYSTAL VIOLET DYES AND CHROMIUM METAL
Objective: The present work was aimed to synthesized the zinc nanoparticles (ZnO NPs) using aqueous leaf extract of Schrebera swietenioides Roxb., and further, the green-synthesized ZnO NPs were studied for its efficacy in the degradation of hazardous dyes like methyl orange, crystal violet and hazardous metal such as chromium.
Methods: The ZnO NPs were synthesized using aqueous leaf extract of S. swietenioides Roxb., as a green reducing agent and 0.1 M Zinc acetate as metal source and the NPs synthesis was completed within a short period of 6 h. The ZnO NPs synthesized were characterized using SEM, TEM, EDS, XRD, FT-IR and UV-visible spectrophotometer. Further, the synthesized NPs were applied for reduction of pollutant days such as methyl orange, crystal violet and pollutant metal chromium.
Results: The synthesis of NPs was monitored by observing the color change in the reaction mixture and UV visible spectral analysis. The UV spectral analysis shows a characteristic absorption wavelength at 379 nm. The synthesized NPs were hexagonal wurtzite form crystals having a spherical shape with rough surfaces with an average size of 68 nm and having 73.7 % of zinc content. At a NPs dose of 1.0 g/l the photocatalytic reduction was observed as 85.33±0.02 %, 86.82±0.095 % and 86.73±0.104 % for crystal violet dye, methyl orange dye and chromium metal, respectively. The NPs shows a high % photocatalytic reduction of chromium metal, crystal violet dye and methyl orange dye with less contact time confirms that the synthesized ZnO NPs were effectively catalyzed the degradation of methyl orange, crystal violet dyes and chromium metal. The NPs were observed to be recyclable and can shows high reduction activity after the completion of three cycles of degradation.
Conclusion: Hence it can be concluded that synthesized greener nanocatalyst was efficient for pollutant treatment and demonstrated the power of green biosynthesis for metallic nanoparticles
SYNTHESIS AND BIOLOGICAL EVALUATION OF SOME NOVEL HETEROCYCLIC MANNICH BASES
Various novel heterocyclic mannich bases were prepared by using Mannich reaction. Acetanilide was treated with substituted benzaldehyde and morpholine / methyl amine to give corresponding titled compounds in good yields. The synthesized compounds were characterized by physical properties and spectral studies (IR, 1H-NMR) and tested for antimicrobial activity against Escherichia coli, Bacillus subtilis by using cup plate method with reference to the standard Streptomycin. All the titled compounds show good antimicrobial activity
Study on knowledge, attitude and practices with respect to antibiotic use among medical students
Background: Antibiotic resistance has emerged as a serious global problem. Irrational prescribing of antibiotics is one of the key factors responsible for the development of antibiotic resistance. As today’s medical students will be the future prescribers their awareness regarding antibiotic resistance and rational prescribing of antibiotics is very much important. The main objective of the study was to evaluate the knowledge, attitude and practices of the medical students towards antibiotic use.Methods: A cross-sectional questionnaire-based study was conducted involving the medical students from all the semesters. A predesigned questionnaire was used to evaluate the knowledge, attitude and practices of the respondents. The response options were ‘yes’ or ‘no’ for some questions, and a 5 point Likert scale used to assess some questions. The data was analyzed using MS office Excel.Results: A total of 457 fully completed questionnaires from the respondents were evaluated. Majority of the respondents (70%) were females, and 91% of the respondents were aware of antibiotic resistance as a global problem. On analysis of score of questions assessing knowledge, 91% of respondents had attained a score in the range of 5-7. Majority (83%) of the respondents used antibiotics only on doctor’s prescription and 74% of the respondents had completed the prescribed course.Conclusions: The present study gives an insight on the knowledge, attitude and practices of medical students on antibiotic use, and can be used as a tool to plan educational strategies to improve the knowledge of the students regarding rational use of antibiotics
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