125 research outputs found

    Antibiotics usage, how well we know it? KAP survey among the dentist population in Mumbai

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    Background: There is a rising concern for antibiotic resistance worldwide, the primary cause of which is overuse and misuse. This study primarily aimed at assessing the knowledge of dental practitioners regarding the current guidelines on use of antibiotics and to identify the shortcomings if any.Methods: Present study was a cross-sectional questionnaire-based study conducted amongst 450 dental practitioners across Mumbai with the help of a self-designed questionnaire. The data was entered into excel sheets and appropriate statistical analysis was done with chi-square test using SPSS version 20.Results: The present study had a response rate of 95%. For the total percentage of patients examined each day that required systemic antibiotics, 36.9% (153) dentists answered 0-5%, followed by 25.3% (105) answered 10-15%. 76.1% (316) dentists came across patients who had self-prescribed antibiotics. 66% (274) dentists had never advised an antibiotic sensitivity/ culture test for their patients. 51.3% (213) dentists came across patients who did not respond to antibiotics. 87.2% (363) dentists were not aware about the ‘AWaRe’ classification of antibiotics given by WHO. 93.3% (383) dentists did not know about antimicrobial stewardship concept.Conclusions: The present study reflected antibiotic overuse and misuse to a certain extent by dental practitioners across Mumbai. Most dentists were unaware about ‘AWaRe’ classification and antimicrobial stewardship. Patient education on ill effects of self-prescription of antibiotics, identification of traits of antibiotic resistance and antibiotic culture tests needs to be prioritized by dentists

    Relevant Result Generation by Harvesting Web Information

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    Multimedia question answering approach has been popular to get information online. The answer of the question is provided in the form of the multimedia. Textual answer is not more informative that’s why it will provide the answer in images and video also. Already existing system work only on the narrow domains and it will complex to generalize to handle question. The proposed system does not answer the question directly. It will having the component such as selection of proper pattern of answer, query generation for multimedia search and multimedia data selection and presentation of result. System having the semantic search. Question is ask by the user in the natural language. In question anwer system will check the question by its keywords

    Atomistic Simulations of the Motion of an Edge Dislocation in Aluminum Using the Embedded Atom Method

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    The motion of an edge dislocation is analyzed for temperatures ranging from 10 K to 200 K and for stresses up to 5 GPa. The dislocation velocity versus the applied shear stress curve can be divided into four regimes corresponding to successively higher shear stresses. In the first regime, the applied shear stress is below the Peierls stress and the dislocation velocity is nominally zero. In the second regime, the dislocation velocity decreases with increasing temperature indicating the presence of a drag due to thermal phonons. In the third regime, the dislocation reaches a sub-sonic limiting velocity that can be predicted by a two-dimensional lattice-dynamics analysis. Such an analysis predicts a limiting velocity for a moving defect when the phase velocity and the group velocity are equal. If even higher shear stresses are applied, the dislocation travels with a transonic velocity of √2 times the shear wave speed

    Fracture in Mode I using a Conserved Phase-Field Model

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    We present a continuum phase-field model of crack propagation. It includes a phase-field that is proportional to the mass density and a displacement field that is governed by linear elastic theory. Generic macroscopic crack growth laws emerge naturally from this model. In contrast to classical continuum fracture mechanics simulations, our model avoids numerical front tracking. The added phase-field smoothes the sharp interface, enabling us to use equations of motion for the material (grounded in basic physical principles) rather than for the interface (which often are deduced from complicated theories or empirical observations). The interface dynamics thus emerges naturally. In this paper, we look at stationary solutions of the model, mode I fracture, and also discuss numerical issues. We find that the Griffith's threshold underestimates the critical value at which our system fractures due to long wavelength modes excited by the fracture process.Comment: 10 pages, 5 figures (eps). Added 2 figures and some text. Removed one section (and a figure). To be published in PR

    Sequence dependence of the folding of collagen-like peptides: Single amino acids affect the rate of triple-helix nucleation

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    The refolding of thermally denatured model collagen-like peptides was studied for a set of 21 guest triplets embedded in a common host framework: acetyl-(Gly-Pro-Hyp)3-Gly-Xaa-Yaa-(Gly-Pro-Hyp)4-Gly-Gly-amide. The results show a strong dependence of the folding rate on the identity of the guest Gly-Xaa-Yaa triplet, with the half-times for refolding varying from 6 to 110 min (concentration = 1 mg/ml). All triplets of the form Gly-Xaa-Hyp promoted rapid folding, with the rate only marginally dependent on the residue in the Xaa position. In contrast, triplets of the form Gly-Pro-Yaa and Gly-Xaa-Yaa were slower and showed a wide range of half-times, varying with the identity of the residues in the triplet. At low concentrations, the folding can be described by third-order kinetics, suggesting nucleation is rate-limiting. Data on the relative nucleation ability of different Gly-Xaa-Yaa triplets support the favorable nature of imino acids, the importance of hydroxyproline, the varying effects of the same residue in the Xaa position versus the Yaa position, and the difficulties encountered when leucine or aspartic acid are in the Yaa position. Information on the relative propensities of different tripeptide sequences to promote nucleation of the triple-helix in peptides will aid in identification of nucleation sites in collagen sequences

    Atomistic simulations of dislocation mobility in Al, Ni and Al/Mg alloys

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    Dislocation velocities and mobilities are studied by Molecular Dynamics simulations for edge and screw dislocations in pure aluminum and nickel, and edge dislocations in Al-2.5%Mg and Al-5.0%Mg random substitutional alloys using EAM potentials. In the pure materials, the velocities of all dislocations are close to linear with the ratio of (applied stress)/(temperature) at low velocities, consistent with phonon drag models and quantitative agreement with experiment is obtained for the mobility in Al. At higher velocities, different behavior is observed. The edge dislocation velocity remains dependent solely on (applied stress)/(temperature) up to approximately 1.0 MPa/K, and approaches a plateau velocity that is lower than the smallest "forbidden" speed predicted by continuum models. In contrast, above a velocity around half of the smallest continuum wave speed, the screw dislocation damping has a contribution dependent solely on stress with a functional form close to that predicted by a radiation damping model of Eshelby. At the highest applied stresses, there are several regimes of nearly constant (transonic or supersonic) velocity separated by velocity gaps in the vicinity of forbidden velocities; various modes of dislocation disintegration and destabilization were also encountered in this regime. In the alloy systems, there is a temperature- and concentration-dependent pinning regime where the velocity drops sharply below the pure metal velocity. Above the pinning regime but at moderate stresses, the velocity is again linear in (applied stress)/(temperature) but with a lower mobility than in the pure metal.Comment: PDF, 30 pages including figures, submitted to Modelling Simul. Mater. Sci. En

    Potassium-selective block of barium permeation through single KcsA channels

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    Ba2+, a doubly charged analogue of K+, specifically blocks K+ channels by virtue of electrostatic stabilization in the permeation pathway. Ba2+ block is used here as a tool to determine the equilibrium binding affinity for various monovalent cations at specific sites in the selectivity filter of a noninactivating mutant of KcsA. At high concentrations of external K+, the block-time distribution is double exponential, marking at least two Ba2+ sites in the selectivity filter, in accord with a Ba2+-containing crystal structure of KcsA. By analyzing block as a function of extracellular K+, we determined the equilibrium dissociation constant of K+ and of other monovalent cations at an extracellular site, presumably S1, to arrive at a selectivity sequence for binding at this site: Rb+ (3 µM) > Cs+ (23 µM) > K+ (29 µM) > NH4+ (440 µM) >> Na+ and Li+ (>1 M). This represents an unusually high selectivity for K+ over Na+, with |ΔΔG0| of at least 7 kcal mol−1. These results fit well with other kinetic measurements of selectivity as well as with the many crystal structures of KcsA in various ionic conditions

    Does prenatal micronutrient supplementation improve children's mental development? A systematic review

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    <p>Abstract</p> <p>Background</p> <p>Although maternal nutrient status influences all aspects of fetal development including the brain, the impact of micronutrient supplementation on the baby's mental function is a topic of debate. This systematic review assesses the effect of single and multiple micronutrient supplementation during pregnancy on offspring mental development.</p> <p>Methods</p> <p>Eleven electronic literature databases were searched using key terms of various combinations and filter string terms. Reference lists of articles selected for review were scanned for citations fitting the same inclusion criteria. Each stage of the literature retrieval and review process was conducted independently by two reviewers. The CONSORT checklist was used to assess study quality.</p> <p>Results</p> <p>A total of 1316 articles were retrieved from the electronic database search, of which 18 met the inclusion criteria and were evaluated. The selected studies were randomized controlled trials published from 1983 to 2010, with high variance in sample size, intervention type, and outcome measures. The median CONSORT score was 15 (range 12 - 19). Due to inconsistent interventions and outcome measures among the studies, no conclusive evidence was found that enhancing the intrauterine environment through micronutrient supplementation was associated with child mental development in a number of dimensions. There was some evidence to support n-3 fatty acids or multi-micronutrients having some positive effect on mental development, but the evidence for single nutrients was much weaker.</p> <p>Conclusions</p> <p>The study of children's mental outcomes as a function of prenatal supplementation is still relatively new, but the results of this systematic review suggest that further work with multiple micronutrients and/or n-3 fatty acids should be conducted.</p
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