452 research outputs found

    Tunneling Study of the Charge-Ordering Gap on the Surface of La0.350_{0.350}Pr0.275_{0.275}Ca0.375_{0.375}MnO3_3 Thin Films

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    Variable temperature scanning tunneling microscopy/spectroscopy studies on (110) oriented epitaxial thin films of La0.350_{0.350}Pr0.275_{0.275}Ca0.375_{0.375}MnO3_3 are reported in the temperature range of 77 to 340 K. The films, grown on lattice matched NdGaO3_3 substrates, show a hysteretic metal-insulator transition in resistivity at 170 K. The topographic STM images show step-terrace morphology while the conductance images display a nearly homogeneous surface. The normalized conductance spectra at low temperatures (T<<150 K) show an energy gap of 0.5 eV while for T\geq180 K a gap of 0.16 eV is found from the activated behavior of the zero bias conductance. The presence of energy gap and the absence of phase separation on the surface over more than 2 μ\mum×\times2 μ\mum area contradicts the metallic behavior seen in resistivity measurements at low temperatures. We discuss the measured energy gap in terms of the stabilization of the insulating CO phase at the film surface.Comment: 5 pages, 5 figures To appear in Phys. Rev.

    Effect of epidural volume extension with colloid on dose requirement for intrathecal spinal block: a double blind prospective study

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    Background: Epidural volume extension (EVE) is a modification of combined- spinal epidural anaesthesia (CSEA) in which fluid is injected in epidural space after the intrathecal block. Fluid in epidural space compress subarachnoid space and causes cephalic spread of intrathecal drug to increase block height. Purpose of study is to determine efficacy of EVE on dose requirement of intrathecal bupivacaine when colloid was used for EVE.Methods: Sixty patients of ASA physical status I or II, scheduled for elective caesarean sections were recruited and randomized into two groups (30 each group). Group 1: CSEA in which spinal block is followed by 10 ml Colloid (HES 6%) in epidural space; Group 2: CSEA but no fluid in epidural space. Onset of sensory block and hemodynamic variables were measured at 5 min. intervals up to 40 minutes then at 10 min. intervals till end of surgery. Ineffective block was top- up by epidural 0.5% bupivacaine in incremental doses.Results: Median effective dose of intrathecal bupivacaine was significantly lower, 4.0 mg (95% CI 4.40-5.60) in group 1 versus 7.0 mg (95% CI 6.93-7.61) in group 2. Only 11 patients required ephedrine in group 1 versus 20 in group 2. Requirement of ephedrine was significantly lower 2.20 (±2.94) mg in group 1 versus 4.0 (±2.88) mg groups 2. Changes in haemodynamic variables from baseline were significantly lower in group 1 than those in group 2.Conclusions: EVE with colloid was effective in lowering dose requirement of spinal bupivacaine while patients hemodynamically were more stable.

    A multiattribute utility evaluation of different methods for the detection of enteric protozoa causing diarrhea in AIDS patients

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    <p>Abstract</p> <p>Background</p> <p>Enteric protozoa and sporozoa have emerged as important opportunistic parasites and can cause fatal infections in AIDS patients. The line of treatment being different for them necessitates an accurate and prompt identification of these to avoid empirical treatment. In this study which is the first of its kind from India we did a comprehensive evaluation of different techniques, comparing them on the basis of the attributes like yield, cost, time taken, expertise and infrastructure. For the first time combination of Calcoflour White and DAPI, a nuclear stain, were used to identify <it>Microsporidia </it>spp. Thus, a diagnostic protocol was devised for rapid, sensitive and cost effective identification of the opportunistic enteric protozoa.</p> <p>Results</p> <p>The organisms isolated from the stool samples of the cases (450 HIV patients) were predominantly <it>Cryptosporidium </it>spp., <it>Microsporidia </it>spp. and <it>Cyclospora </it>spp. Interestingly, the control group (200 relatives of the patients who were HIV negative) showed a high incidence (21%) of <it>Cryptosporidium </it>spp. We found a significant increase in the sensitivity of microscopy in detecting <it>Cryptosporidium </it>spp. and <it>Cyclospora </it>spp. after formol ether concentration. Kinyoun's staining was better compared to Modified safranin staining for <it>Cryptosporidium </it>spp. identification. Although ELISA had a sensitivity of 93.25% and specificity of 97% for <it>Cryptosporidium </it>spp. detection, we ranked Kinyoun's staining better than ELISA because it is not affordable to most of our patients. For detecting <it>Cyclospora cayetanensis</it>, autoflourescence was the easiest and most cost effective method followed by Safranin technique. Combination of Calcoflour White stain and DAPI gave good results for the identification of <it>Microsporidia </it>spp. We assessed the above techniques and graded the attributes in the following descending order: cost effectiveness, sensitivity, ease of use and interpretation, time taken for the procedure and batch testing.</p> <p>Conclusion</p> <p>Thus, we conclude that a combination of minimum three procedures should be carried out for the screening of stool specimens of HIV positive patients. Kinyoun's staining should be made mandatory for every diarrheal stool sample from HIV patients. Also every laboratory should assign its own value to the attributes and apply Multiattribute utility theory or the Analytical hierarchy process to decide the most appropriate methodology.</p

    Mechanical, Electrical and Thermal Properties of Nylon-66/Flyash Composites: Effect of Flyash

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    In the current study, the effect of flyash (FA) on the physic-mechanical, electrical, thermal and morphological behavior of nylon-66 (PA) was investigated. PA/FA composites were prepared by melt mixing via twin screw extruder, with varying weight percent (5 wt %, 10 wt %, 15 wt % and 20 wt %) of flyash. The results of composites were optimized and compared with virgin nylon-66. Mechanical and electrical properties of composites improved up to 10 wt% of FA loading without compromising the properties. The flyash filled nylon-66 composites showed a low abrasive wear rate. Increase the heat distortion temperature of composites with an increase in weight percent of flyash while opposing the melt flow rate. Flyash filler enhances the stiffness of plastics but significantly reduces the impact properties. Dispersion of flyash was examined by impact fracture surface of composites using a scanning electron microscope

    Guggulsterone Targets Smokeless Tobacco Induced PI3K/Akt Pathway in Head and Neck Cancer Cells

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    Epidemiological association of head and neck cancer with smokeless tobacco (ST) emphasizes the need to unravel the molecular mechanisms implicated in cancer development, and identify pharmacologically safe agents for early intervention and prevention of disease recurrence. Guggulsterone (GS), a biosafe nutraceutical, inhibits the PI3K/Akt pathway that plays a critical role in HNSCC development. However, the potential of GS to suppress ST and nicotine (major component of ST) induced HNSCC remains unexplored. We hypothesized GS can abrogate the effects of ST and nicotine on apoptosis in HNSCC cells, in part by activation of PI3K/Akt pathway and its downstream targets, Bax and Bad.Our results showed ST and nicotine treatment resulted in activation of PI3K, PDK1, Akt, and its downstream proteins--Raf, GSK3β and pS6 while GS induced a time dependent decrease in activation of PI3K/Akt pathway. ST and nicotine treatment also resulted in induction of Bad and Bax phosphorylation, increased the association of Bad with 14-3-3ζresulting in its sequestration in the cytoplasm of head and neck cancer cells, thus blocking its pro-apoptotic function. Notably, GS pre-treatment inhibited ST/nicotine induced activation of PI3K/Akt pathway, and inhibited the Akt mediated phosphorylation of Bax and Bad.In conclusion, GS treatment not only inhibited proliferation, but also induced apoptosis by abrogating the effects of ST/nicotine on PI3K/Akt pathway in head and neck cancer cells. These findings provide a rationale for designing future studies to evaluate the chemopreventive potential of GS in ST/nicotine associated head and neck cancer

    Mapping of the Indian fisheries growth rate and fish consumption through GIS

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    In the present study, Indian fisheries growth rate and fish consumption have been analyzed through GIS mapping. The analyses were based on the state-level fisheries data of India collected from the secondary sources. Accordingly, the paper contains one thematic map containing two layers. To achieve this, all the data have been brought into a tabular form through Microsoft Excel and then joined to Map Info Professional Version 8.0 GIS software with digitized map oflndia for further analysis to generate thematic maps

    A study of bone mineral density among people living with HIV in India and its correlation with CD4 count

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    Background: Data on the prevalence of osteoporosis in HIV patients in Asian population is scarce this study was done to find out the prevalence of osteoporosis in HIV infected patients and its correlation with CD4 counts.Methods: This cross- sectional study was conducted in NACO- ART center of tertiary care hospital. Total 115 HIV patients were included in this study which were divided into ART naive (n= 69) and patients taking ART (n= 46). We analysed BMD by DEXA in 115 HIV positive patients and 78 HIV negative age and sex matched controls. Correlation of BMD with a CD4 count and ART regimen was studied.Results: BMD was found to be low in HIV positive patients. T score in HIV positive patients was significantly lower (p<0.05) as compared to the HIV negative control group. The prevalence of osteopenia and osteoporosis in HIV positive patients was 50.4% and 29.6% respectively, as compared to 23.1% and 2.6% in HIV negative controls. BMD showed relation with CD4 count. We did not find any statistical difference between any ART regimen and BMD.Conclusions: The prevalence of osteopenia and osteoporosis in HIV infected cases was higher as compared to HIV negative controls and higher in ART group as compared to ART naïve group. Low BMD levels show correlation with low CD4 count. We recommend that HIV positive patients especially with advanced stage of disease, low CD4 count should be screened for low BMD by DEXA scan for osteoporosis and managed accordingl

    Phytotoxic effects of chromium and tannery effluent on growth and metabolism of Phaseolus mungo Roxb.

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    Abstract: The various dilution levels of treated tannery effluent (T.E.) (10, 25, 50 and 100 %) and Cr 6+ (0.5, 2.0, 5.0 and 10 ppm) were used in experiment to know their effect on seed germination, seedling growth, pigments and enzymes content in Black gram (Phaseolus mungo Roxb.). Chromium is known as the main toxic component of tannery effluent so its various concentration were given to know their effects. For the recovery of plant damage, protective value of 10 and 25 ppm of zinc, potassium and iron sulphate were also given with 50 % treated tannery effluent and 10 ppm Cr 6+ levels in separate petridishes. The different concentrations of tannery effluent and Cr 6+ showed significant reduction in germination percentage, seedling growth (plumule and radicle length, number of lateral roots, fresh and dry weight, and moisture %) and pigments (chlorophyll, pheophytin and carotenoids) with increase in concentrations. The lower doses of tannery effluent (10%) and Cr 6+ (0.5, 2 and 5 ppm) slightly increases the pigments concentration. The amylase activity and total sugar contents were also significantly decreased while catalase and peroxidase activity showed significant increase with rise in concentrations of treatments. The lower concentrations of tannery effluent (dilution 10 and 25%) and Cr 6+ (0.5 and 2 ppm) showed significant increase in total protein contents while decrease at higher concentrations. The zinc, potassium and iron treatments led to recover the damage caused by chromium and tannery effluent in all parameters. In recovery treatments zinc showed highest and significant recovery in maximum parameters. Iron also showed almost similar effect to the zinc while potassium showed minimum recovery

    The relation of serum GGT level in patients with non valvular atrial fibrillation and normal sinus rhythm

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    Background: The primary objective of the study was to assess and compare the relation of serum GGT level in patients with non valvular atrial fibrillation and normal sinus rhythm. The fundamental mechanisms underlying AF remains poorly understood. Oxidative stress is hypothesized to induce and maintain nonvalvular atrial fibrillation particularly in elderly patients. GGT levels are increased in patients with chronic inflammation. Increased serum levels of GGT are found in chronic nonvalvular atrial fibrillation (AF) patients as compared with patients in sinus rhythm.Methods: We included 75 patients of nonvalvular atrial fibrillation and 75 patients of sinus rhythm after applying exclusion criteria. Serum level of gamma glutamyl transrerase (GGT) of both the groups was compared.Results: Presence of coronary artery disease, hypertension, gender, hyperlipidemia, diabetes mellitus and smoking status were comparable between the 2 groups (P > 0.05 for all). Serum gamma glutamyl transferase activity in 75 cases was 71.45±26.21 with maximum being 147 IU/L more than the normal range for age, whereas in controls it was 19.68±5.53 i.e. much within the normal range for age.Conclusions: At the end of the study we concluded that serum GGT levels were significantly higher in patients with chronic nonvalvular atrial fibrillation (AF) patients as compared with patients in sinus rhythm

    Diarrhea, CD4 counts and enteric infections in a hospital - based cohort of HIV-infected patients around Varanasi, India

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    Background: As most of the studies in HIV patients with diarrhea were cross sectional, focusing on the etiological agents, we are reporting data on the rate of diarrhea, associations between diarrhea and CD4 counts and variation in frequency of identifying a pathogen with consistency of diarrhea and duration in a prospective hospital based study. Methods: Stool specimens were obtained between Jan 2001 and April 2003 from HIV infected adults with diarrhea presenting to Infectious Disease clinic, Banaras Hindu University, Varanasi. In all patients with diarrhea, specimens were examined by microscopy and cultures to identify pathogens. Results: During the study, 630 person years of observations with diarrhea were analyzed. 140 stool samples were collected representing 43% of episodes of reported diarrhea. Positivity of finding a pathogen from watery stools and formed stools were 40%&amp;24% respectively (p &lt; 0.01) probably due to associated inflammation is more in watery diarrhea. Patients having chronic diarrhea are 2.25 (95%CI 1.52-2.81) times at more risk of developing other opportunistic infections compared to those who don't have. However this is not true with the acute diarrhea where risk of harboring the opportunistic infections remain same. Conclusion: Diarrhea was most strongly associated with low CD4 counts. Over two-thirds of diarrheal episodes were undiagnosed, suggesting that unidentified agents or primary HIV enteropathy are important causes of diarrhea in this population. There is a strong negative association between duration of diarrhea and CD4 levels
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