74 research outputs found

    Structural and doping effects in the half-metallic double perovskite A2A_2CrWO6_6

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    he structural, transport, magnetic and optical properties of the double perovskite A2A_2CrWO6_6 with A=Sr, Ba, CaA=\text{Sr, Ba, Ca} have been studied. By varying the alkaline earth ion on the AA site, the influence of steric effects on the Curie temperature TCT_C and the saturation magnetization has been determined. A maximum TC=458T_C=458 K was found for Sr2_2CrWO6_6 having an almost undistorted perovskite structure with a tolerance factor f1f\simeq 1. For Ca2_2CrWO6_6 and Ba2_2CrWO6_6 structural changes result in a strong reduction of TCT_C. Our study strongly suggests that for the double perovskites in general an optimum TCT_C is achieved only for f1f \simeq 1, that is, for an undistorted perovskite structure. Electron doping in Sr2_2CrWO6_6 by a partial substitution of Sr2+^{2+} by La3+^{3+} was found to reduce both TCT_C and the saturation magnetization MsM_s. The reduction of MsM_s could be attributed both to band structure effects and the Cr/W antisites induced by doping. Band structure calculations for Sr2_2CrWO6_6 predict an energy gap in the spin-up band, but a finite density of states for the spin-down band. The predictions of the band structure calculation are consistent with our optical measurements. Our experimental results support the presence of a kinetic energy driven mechanism in A2A_2CrWO6_6, where ferromagnetism is stabilized by a hybridization of states of the nonmagnetic W-site positioned in between the high spin Cr-sites.Comment: 14 pages, 10 figure

    Effect of Standard Treatment Guidelines with or without Prescription Audit on Prescribing for Acute Respiratory Tract Infection (ARI) and Diarrhoea in some Thana Health Complexes (THCs) of Bangladesh

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    Inappropriate prescribing for ARI and diarrhoea is a serious health problem in many developing countries including Bangladesh. A baseline retrospective prescribing survey for ARI and diarrhoea have been conducted in randomly selected 60 thana health complexes (THCs) of Dhaka division of Bangladesh. In the 38 of 60 THCs, the prescribers did not comply with the standard treatment guidelines (STG) for ARI. They are marked as \u27unsatisfactory performers\u27. In these THCs unnecessary antibiotics were prescribed in more than 50% of the encounters. The study further revealed that in 26 THCs, comprising 41.6% of the 38 THCs, the situation was even worse regarding the indiscriminate use of antibiotics. In these THCs antibiotics were prescribed in \u3e or =72% of the encounters. For diarrhoea, only in 8.3% of the THCs antibiotics were prescribed in \u3e or =50% of the encounters. Encouragingly, most of the prescribers prescribed ORS. So the diarrhoea cases were dropped from the intervention. The 24 out of 26 worse performing THCs for ARI management, were grouped into three groups: Group-I (implementing STG+ Audit), Group-II (STG) and Group-III (no intervention, control). The prescribers of the THCs belonging to Group-I and Group-II received STG+Audit and STG only respectively as intervention(s). On the contrary, the prescribers of the THCs of Group-III (control) did not receive any intervention. It was observed that after the implementation of interventions the use of the unnecessary antibiotics to treat ARI was significantly reduced (p\u3c0.01) compared to pre-intervention period in Group-I (STG+Audit). In this group highly significant (p\u3c0.000) reduction in antibiotics use was achieved in 6 out of 8 THCs. The average reduction in antibiotic use in terms of encounters was 23.7 and 15.2% in the Group-I and Group-II respectively owing to the intervention(s). Significant reduction in antibiotic use in terms of THCs was 3 (out of 8 THCs) and 2 (out of 8 THCs) belonging to the Group-II and Group-III respectively. When compensated for the change in the control group, the reduction of antibiotic use in terms of encounters was 15.2 and 6.9% in the THCs of the Group-I and Group-II respectively due to introduction of the interventions. The study concludes that STG supported by prescription audit are highly effective interventions to change the prescribing behaviour of the prescribers for ARI in the THCs

    An artificial fish swarm filter-based Method for constrained global optimization

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    Ana Maria A.C. Rocha, M. Fernanda P. Costa and Edite M.G.P. Fernandes, An Artificial Fish Swarm Filter-Based Method for Constrained Global Optimization, B. Murgante, O. Gervasi, S. Mirsa, N. Nedjah, A.M. Rocha, D. Taniar, B. Apduhan (Eds.), Lecture Notes in Computer Science, Part III, LNCS 7335, pp. 57–71, Springer, Heidelberg, 2012.An artificial fish swarm algorithm based on a filter methodology for trial solutions acceptance is analyzed for general constrained global optimization problems. The new method uses the filter set concept to accept, at each iteration, a population of trial solutions whenever they improve constraint violation or objective function, relative to the current solutions. The preliminary numerical experiments with a wellknown benchmark set of engineering design problems show the effectiveness of the proposed method.Fundação para a Ciência e a Tecnologia (FCT

    PHYTOCHEMICAL INVESTIGATION AND EVALUATION OF ANTIOXIDANT AND THROMBOLYTIC PROPERTIES OF LEAVE EXTRACTS OF GARDENIA CORONARIA BUCH-HAM

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    Objective: The objective of this study was assessing the diverse pharmacological efficacies of methanolic extracts of the whole plant of Gardenia coronaria Buch-Ham This study illustrates the phytochemicals, antioxidants and thrombolytic activity which have the possibility to be used in the coming future to open a new line of investigation. The Gardenia coronaria, one of the necessary traditional medicinal plants in Bangladesh. In the rural area this plant is used by a lot of people as a treatment from various disease. Methods: Total sum of the flavonoids was spectrophotometrically ascertained with the help of aluminum chloride colorimetric assay as total phenolic and tannin content by Folin Chiocalteu’s reagent. Antioxidant activity, ascertained by DPPH (α, α-diphenyl-β-picrylhydrazyl) free radical scavenging assay giving some comparison between the resultant activity with the standard. The thombolytic activity was assessed based on the method of minor alterations. Results: The percentage of clot lysis was 87.58% when 100 μl of streptokinase (30,000 I.U.), and the methanolic extract displayed the least clot lysis activity (26.79%), much less compared to the standard. It can be elicited that the extract of Gardenia coronaria Buch-Ham contains antioxidant and thrombolytic activity. The potential of these activities probably because of the availability of most of the phytochemicals supporting previous claims and verify its uses as an expected folk medicine.                                        Peer Review History: Received 9 January 2020;   Revised 25 January; Accepted 4 March, Available online 15 March 20200 Academic Editor: Dr. Amany Mohamed Alboghdadly, Princess Nourah bint abdulrahman university, Riyadh, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 4.5/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Dr. Gehan Fawzy Abdel Raoof Kandeel, Pharmacognosy Department, National Research Centre, Dokki, 12622,  Giza, Egypt, [email protected]  Dr. Marwa A. A. Fayed, University of Sadat City, Egypt, [email protected] Similar Articles: COMPARATIVE ANALYSIS OF THE PHYTOCHEMICAL COMPOSITIONS OF LEAF, STEM-BARK AND ROOT OF AZADIRACHTA INDICA (NEEM) EXTRACTION AND PHYSICOCHEMICAL CHARACTERIZATION OF NOVEL POTENT MUCOADHESIVE BIO-MATERIAL OBTAINED FROM THE FRESH FRUITS PULP OF ACHRAS ZAPOTILL
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