180 research outputs found

    Ab initio determination of ion-traps in silver-doped chalcogenide glass

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    We present a microscopic picture of silver dynamics in GeSe3_{3}:Ag glass obtained from {\it ab initio} simulation. The dynamics of Ag is explored at two temperatures, 300K and 700K. In the relaxed network, Ag occupies bond centers between suitably separated host sites. At 700K, Ag motion proceeds via a trapping-release dynamics, between "super traps" or cages consisting of multiple bond-center sites in a small volume. Our work offers a first principles identification of trapping centers invoked in current theories, with a description of their properties. We compute the charge state of the Ag in the network, and show that it is neutral if weakly bonded and Ag+^+ if in a trapping center.Comment: submitted to pr

    A review of strategies to improve rational prescribing in asthma.

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    Background: There are well-recognised gaps between evidence-based recommendations and prescribing practices in asthma. While different strategies have been devised to improve rational prescribing, the impact of these is uncertain. Aim: To examine the characteristics and effectiveness of strategies to improve rational prescribing in asthma. Method: We systematically searched electronic databases to find studies that reported on strategies to improve prescribing in asthma, or included rational prescribing as one of the main components of the program. Results: There were thirteen relevant studies. All of the strategies described in these studies involved physician education using a variety of modalities; two of the trials also included patient-specific prescribing direction. Twelve of thirteen studies reported improved prescribing practice. There was significant heterogeneity in the interventions and outcome criteria employed by the studies. Conclusion: Strategies to improve rational prescribing in asthma show promise, but the significant methodological heterogeneity, and the absence in most cases of demonstrable clinical benefit, raise concerns about their applicability in clinical practice. Keywords: asthma, inappropriate prescribing, medication therapy management, physician's practice patterns, quality improvemen

    Ab initio determination of ion-traps in silver-doped chalcogenide glass

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    We present a microscopic picture of silver dynamics in GeSe3_{3}:Ag glass obtained from {\it ab initio} simulation. The dynamics of Ag is explored at two temperatures, 300K and 700K. In the relaxed network, Ag occupies bond centers between suitably separated host sites. At 700K, Ag motion proceeds via a trapping-release dynamics, between "super traps" or cages consisting of multiple bond-center sites in a small volume. Our work offers a first principles identification of trapping centers invoked in current theories, with a description of their properties. We compute the charge state of the Ag in the network, and show that it is neutral if weakly bonded and Ag+^+ if in a trapping center.Comment: submitted to pr

    Maximum Penetration Height and Intrusion Speed of Weak Symmetric Plane Fountains in Linearly Stratified Fluids

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    The flow behavior of weak symmetric plane fountains in linearly stratified fluids is studied numerically with three-dimensional simulations over a range of the Froude ((Formula presented.)), Reynolds ((Formula presented.)), and stratification numbers (s). The two main parameters describing the fountain characterization are the dimensionless maximum fountain penetration height ((Formula presented.)) and intrusion velocity ((Formula presented.)), which differ significantly at different flow development stages. It was found that the stratification stabilizes the symmetry of the weak fountains, which makes the fountain become asymmetric at a larger (Formula presented.) value, and (Formula presented.) at the fully developed stage continues to increase as a result of the intrusion, which continually changes the ambient fluid stratification features, thus the buoyant force. The evolution of intrusion experiences three distinct stages. Both (Formula presented.) and s have effects on (Formula presented.) and (Formula presented.), with the effect of (Formula presented.) usually larger than that of s. The overall impacts of (Formula presented.) and s can be quantified in terms of (Formula presented.), with a and b varying for different parameters. With numerical results, empirical correlations are produced in terms of (Formula presented.) for each relevant parameter, which generally predict the results very well

    ASSESSMENT OF LEVEL OF BLOOD GLUCOSE IN TYPE-2 DIABETIC PATIENTS UNDERGOING DENTAL TREATMENTS

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    Aims and objectives: The main objective of the study is to analyze the level of blood glucose in type-2 diabetic patients undergoing dental treatments. Material and methods: This cross sectional study was conducted in THQ Hospital, Haveli Lakhan during March 2018 to November 2018. The data was collected from 100 diabetic patients who undergo dental procedures and treatments. Venous blood sample was collected from each patient and then centrifuged this sample for the separation of serum. The sample included only the patients who presented blood glucose levels and HbA1c demonstrating that diabetes was under control. They should also be under continuous oral hypoglycemic drugs treatment, medical supervision and no dose alterations. Results: The data was collected from 100 diabetic patients. There is no statistically significant difference between the groups, regarding the evaluation period (p> 0.05). For heart rate, there was no statistically significant difference between the groups regarding the evaluation period (p> 0.05). However, regarding the comparison between the periods statistically significant differences were observed (p <0.05) for the T1 and T2 values for group. However, when comparing the periods statistically significant differences were observed (p <0.05) for T2 and T3 values for group. Conclusion: It is concluded that periodontal disease is the main oral clinical manifestation in diabetic patients

    A semi-quantitative scattering theory of amorphous materials

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    It is argued that topological disorder in amorphous solids can be described by local strains related to local reference crystals and local rotations. An intuitive localization criterion is formulated from this point of view. The Inverse Participation Ratio and the location of mobility edges in band tails is directly related to the character of the disorder potential in amorphous solid, the coordination number, the transition integral and the nodes of wave functions of the corresponding reference crystal. The dependence of the decay rate of band tails on temperature and static disorder are derived. \textit{Ab initio} simulations on a-Si and experiments on a-Si:H are compared to these predictions.Comment: 4 pages, 2 figures, will be submitted to Phys. Rev. Let

    The potential protective effect of metformin on selective cardiac biomarkers in diabetic male rats

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    Metformin, a biguanide, first line antidiabetic agent, undergoes extensive debate to explain its possible cardioprotective effect. This study represents an attempt to help clarifying this cardioprotective effect. 24rats divided into three diabetic group (8 rats for each) (diabetes induced by Streptozocin 60 mg/kgi.p.). Diabetic groups treated with (saline, 75 mg/kg metformin and 150 mg/kg metformin, i.p.) for 6 weeks, then cardiac stress was induced by isoproterenol (ISO) (150 mg/kg i.p.) for two successive days. Selective biomarkers were assessed; brain natriuretic peptide (BNP), matrix metalloproteinase - 1 (MMP-1) and histopathology examination. The results of this study showed that metformin produce a dose dependent cardioprotection effect in diabetic rats

    The Protective Effect of Metformin Against Doxorubicin Induced Cardiotoxicity in Rabbits

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    Back ground: Doxorubicin is a very effective anticancer therapy of the anthracycline's family used in many pediatric and adult cancers. However, due to severe cardiotoxicity adverse effect, the uses of doxorubicin are limited. Metformin reducing basal and postprandial glucose levels. Metformin has a good treatment efficacy and safety profile in treatment of T2DM in conjunction with lifestyle modification. Metformin have a cardioprotective effect in addition to reducing basal and postprandial levels of glucose by decreasing the production of reactive oxygen species, maintaining energy homeostasis and apoptosis regulation by its activation of adenosine monophosphate-activated protein kinase.  Method: Thirty-six white male rabbits randomly divided to six groups, each comprising of six rabbits. 1- Control group injected 2 ml saline single dose intraperitoneally. 2- Metformin group 300 mg/kg/daily for 14 days orally. 3- Acute doxorubicin induction group 16 mg/ kg intraperitoneally as a single dose. 4- Chronic doxorubicin induction group 4mg/kg intraperitoneally twice a week for two weeks. 5- Metformin+ acute doxorubicin induction group 16 mg/kg intraperitoneally single dose and Metformin 300 mg/kg/daily for 14 days orally, three days before doxorubicin treatment. 6- Metformin + chronic doxorubicin induction group 4 mg/kg intraperitoneally, twice a week for two weeks and Metformin 300 mg/kg/daily for 14 days orally, three days before doxorubicin treatment.  Result: our results revealed the treatment with metformin significantly (p < 0.05) reduced the serum level of troponin I and MMP2 in Metformin+ acute doxorubicin induction and Metformin + chronic doxorubicin induction groups in comparison with the acute doxorubicin and chronic doxorubicin groups. Conclusion: From these results in this study, we can conclude that metformin has a cardioprotective effect against doxorubicin induced cardiotoxicity in acute and also the chronic induction by decreasing serum level of troponin I and MMP2

    A large spin-up rate measured with INTEGRAL in the High Mass X-ray Binary Pulsar SAXJ2103.5+4545

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    The High Mass X-ray Binary Pulsar SAXJ2103.5+4545 has been observed with INTEGRAL several times during the last outburst in 2002-2004. We report a comprehensive study of all INTEGRAL observations, allowing a study of the pulse period evolution during the recent outburst. We measured a very rapid spin-up episode, lasting 130days, which decreased the pulse period by 1.8s. The spin-up rate, pdot=-1.5e-7 s/s, is the largest ever measured for SAXJ2103.5+4545, and it is among the fastest for an accreting pulsar. The pulse profile shows evidence for temporal variability, apparently not related to the source flux or to the orbital phase. The X-ray spectrum is hard and there is significant emission up to 150keV. A new derivation of the orbital period, based on RXTE data, is also reported.Comment: 8 pages, 7 figures, accepted for publication in A&

    Probing stellar winds and accretion physics in high-mass X-ray binaries and ultra-luminous X-ray sources with LOFT

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    This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of high-mass X-ray binaries and ultra-luminous X-ray sources. For a summary, we refer to the paper.Comment: White Paper in Support of the Mission Concept of the Large Observatory for X-ray Timing. (v2 few typos corrected
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