105 research outputs found
Determination of Material Parameters during Superplastic Forming of AA 5086 Alloy
AbstractSuperplastic forming (SPF) process is an important advanced manufacturing method that has the benefit of certain materials capability to undergo large strains to failure when deformed atprominent temperature and at lesser strain rates. The major problem encountered during the Superplastic Forming of sheet metals, is the vagueness in determining the specific time necessary for attaining the steady state temperature, forming time by the sheet material to arrive the required geometry for a given input parameters such as pressure and temperature, thickness distribution along the profile. Hence in this work, a steady state equation is derived to determine the approximate time for the sheet metal to attain the set temperature and also the most favorable temperature and pressure necessary for achieving the deformation of the workpiece based on equal thickness distribution is determined. Graphs are plotted to show the varying parameters at different temperature and pressure values
INHIBITIVE EFFECT OF WRIGHTIA TINCTORIA LEAVES AS GREEN INHIBITOR FOR MILD STEEL IN ACID MEDIUM
The inhibition efficacy of Wrightia tinctoria leaves (WTL) extract on mild steel in 1.0N hydrochloric acid with various exposure time (24 to 360hrs) and temperature (313 to 333K) are investigated by mass loss measurements. The value of inhibition efficiency is increased with increase of inhibitor concentration and gradually decreased with rise in temperature is suggestive of physisorption. The adsorption of WTL onto the mild steel surface is found to follow the Langmuir adsorption isotherm. Both kinetic (activation energy and change in heat of absorption) as well as thermodynamics parameters (adsorption of enthalpy, entropy and Gibbs free energy) are calculated and discussed in details. The characterization of alcoholic extract of inhibitor and corrosion products formed on the metal surface is analyzed by UV, FT-IR and SEM spectral studies
Saccharin test of mucociliary clearance in Kartagener's syndrome
Saccharin test is a method for estimating mucociliary clearance in the upper respiratory passage. Its application in a clinically diagnosed patient with Kartagener's syndrome is reported
Long term follow up of HIV-infected patients with tuberculosis treated with 6-month intermittent short course chemotherapy
Background . Tuberculosis occurs in 60%–70% of HIVpositive persons in India. The outcome of HIV-positive patients treated with 6-month intermittent short course antituberculosis regimens in India is not well described. Methods . This was a prospective observational feasibility study of 71 patients with HIV and tuberculosis who were treated with category I regimen of the Revised National Tuberculosis Control Programme (ethambutol, isoniazid, rifampicin and pyrazinamide thrice weekly for the initial 2 months followed by rifampicin and isoniazid thrice weekly for the next 4 months). Sputum was examined by smear and culture for Mycobacterium tuberculosis every month up to 24 months. Chest X-ray, CD4 cell count and viral load were done prior to and at the end of treatment. None of the patients received antiretroviral therapy. Results . We present here the treatment response of patients with sputum culture-positive pulmonary tuberculosis to category I regimen. By efficacy analysis, among 43 patients treated with category I regimen, sputum smear conversion was observed in 79% and culture conversion in 82% at the second month. A favourable response was seen in 72% of patients. The mean (SD) CD4% fell from 12.6 (5.9) to 8.9 (4.9) (p<0.001) with no significant change in mean (SD) CD4 cell count (169 [126] to 174 [158]; ns) at the end of treatment. Viral load change from 1.8x105 at baseline to 1.3x105 at the end of treatment was not statistically significant. Thirty-one patients, who completed the full course of treatment, were declared cured and were followed
up for 24 months. Twelve had recurrent tuberculosis (39%); 16 of 43 (37%) patients had died by the end of 24 months, twothirds due to causes other than tuberculosis. Conclusion . Though the early bacteriological response to intermittent short course antituberculosis regimen was satisfactory, the overall outcome was adversely affected by the high mortality (during and after completion of treatment) and recurrence rate among HIV-infected patients with tuberculosis. Immune status deteriorated in spite of antituberculosis treatment, highlighting the need for antiretroviral treatment in addition to antituberculosis treatment to improve the long term outcome. The results of this pilot study need to be confirmed by larger studies
Domain Structure of the Staphylococcus aureus Collagen Adhesin
Sequence analysis of surface proteins from Gram-positive bacteria indicates a composite organization consisting of unique and repeated segments. Thus, these proteins may contain discrete domains that could fold independently. In this paper, we have used a panel of biophysical methods, including gel permeation chromatography, analytical ultracentrifugation, circular dichroism, and fluorescence spectroscopy, to analyze the structural organization of the Staphylococcus aureus collagen adhesin, CNA. Our results indicate that the structure, function, and folding of the ligand-binding domain (A) are not affected by the presence or absence of the other major domain (B). In addition, little or no interaction is observed between the nearly identical repeat units within the B domain. We propose that CNA is indeed a mosaic protein in which the different domains previously indicated by sequence analysis operate independently
Age for measles immunization seroconversion after measles vaccination at 6-8 months of age - A randomised controlled trial
The, objective of the study was to compare the
effectiveness of measles vaccine by seroconversion
in vaccinated children with non-vaccinated children
of 6 to 8 months age group in a city slam community
so as to study the feasibility of advancing the age
of immunization. Live attenuated lyophilized
Schwartz strain of measles vaccine was used.
Hemagglutination inhibition (HI) antibody was
estimated. Seroconversion was defined as either the
conversion of negative to positive or a two fold rise
in titre. One hundred and thirty two children
completed the study. There was no difference in
the age, sex and nutritional status between vaccinated
and non-vaccinated groups (p>0.7). The
seroconversion rate in the vaccinated group was
65% and in the non-vaccinated group was 26%.
The age, sex and nutritional status did not significantly
affect the seroconversion. Oar data suggest
that immunization with measles vaccine may be
effective as early as 6 months of age. Immunization
at 6 months may be needed at least for children in
densely populated areas like cities and towns
Role of sortase-dependent pili of Bifidobacterium bifidum PRL2010 in modulating bacterium-host interactions
Bifidobacteria represent one of the dominant groups of microorganisms colonizing the human infant intestine. Commensal bacteria that interact with a eukaryotic host are believed to express adhesive molecules on their cell surface that bind to specific host cell receptors or soluble macromolecules. Whole-genome transcription profiling of Bifidobacterium bifidum PRL2010, a strain isolated from infant stool, revealed a small number of commonly expressed extracellular proteins, among which were genes that specify sortase-dependent pili. Expression of the coding sequences of these B. bifidum PRL2010 appendages in nonpiliated Lactococcus lactis enhanced adherence to human enterocytes through extracellular matrix protein and bacterial aggregation. Furthermore, such piliated L. lactis cells evoked a higher TNF-α response during murine colonization compared with their nonpiliated parent, suggesting that bifidobacterial sortase-dependent pili not only contribute to adherence but also display immunomodulatory activity
Ambulatory Multi-Drug Resistant Tuberculosis Treatment Outcomes in a Cohort of HIV-Infected Patients in a Slum Setting in Mumbai, India
Background: India carries one quarter of the global burden of multi-drug resistant TB (MDR-TB) and has an estimated 2.5 million people living with HIV. Despite this reality, provision of treatment for MDR-TB is extremely limited, particularly for HIV-infected individuals. Médecins Sans Frontières (MSF) has been treating HIV-infected MDR-TB patients in Mumbai since May 2007. This is the first report of treatment outcomes among HIV-infected MDR-TB patients in India.
Methods: HIV-infected patients with suspected MDR-TB were referred to the MSF-clinic by public Antiretroviral Therapy (ART) Centers or by a network of community non-governmental organizations. Patients were initiated on either empiric or individualized second-line TB-treatment as per WHO recommendations. MDR-TB treatment was given on an ambulatory basis and under directly observed therapy using a decentralized network of providers. Patients not already receiving ART were started on treatment within two months of initiating MDR-TB treatment.
Results: Between May 2007 and May 2011, 71 HIV-infected patients were suspected to have MDR-TB, and 58 were initiated on treatment. MDR-TB was confirmed in 45 (78%), of which 18 (40%) were resistant to ofloxacin. Final treatment outcomes were available for 23 patients; 11 (48%) were successfully treated, 4 (17%) died, 6 (26%) defaulted, and 2 (9%) failed treatment. Overall, among 58 patients on treatment, 13 (22%) were successfully treated, 13 (22%) died, 7 (12%) defaulted, two (3%) failed treatment, and 23 (40%) were alive and still on treatment at the end of the observation period. Twenty-six patients (45%) experienced moderate to severe adverse events, requiring modification of the regimen in 12 (20%). Overall, 20 (28%) of the 71 patients with MDR-TB died, including 7 not initiated on treatment.
Conclusions: Despite high fluoroquinolone resistance and extensive prior second-line treatment, encouraging results are being achieved in an ambulatory MDR-T- program in a slum setting in India. Rapid scale-up of both ART and second-line treatment for MDR-TB is needed to ensure survival of co-infected patients and mitigate this growing epidemic.</br
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