392 research outputs found

    A mechanical behavior law for the numerical simulation of the mushy zone in welding

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    The aim of this work is to propose a mechanical behavior law dedicated to the mushy zone located between the solid phase and the weld pool in welding. The objective is to take into account of the influence of the mushy zone in the simulation of welding in order to improve the computation of induced effects such as residual stresses

    Voltammetric determination of melatonin in tablet dosage forms and human serum

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    The electrochemical oxidation of melatonin is studied in Britton-Robinson buffer in the pH range 2.2-11.8 by cyclic voltammetry at glassy carbon electrode. Three irreversible, diffusion-controlled oxidation peaks were obtained. The utility of using differential pulse and square wave techniques for determination of melatonin was examined. Different parameters affecting the peak current were analylzed and at optimum conditions, linear calibration plots from 0.02-0.5 mM and 0.04 to 0.5 mM of melatonin were obtained applying the two techniques, respectively. The differential pulse mode was successfully applied to the determination of melatonin in commercial tablets containing about three-folds of vitamin B6 without previous separation. The same technique was also used for melatonin determination in human serum with acceptable accuracy.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Voltammetric determination of melatonin in tablet dosage forms and human serum

    Get PDF
    The electrochemical oxidation of melatonin is studied in Britton-Robinson buffer in the pH range 2.2-11.8 by cyclic voltammetry at glassy carbon electrode. Three irreversible, diffusion-controlled oxidation peaks were obtained. The utility of using differential pulse and square wave techniques for determination of melatonin was examined. Different parameters affecting the peak current were analylzed and at optimum conditions, linear calibration plots from 0.02-0.5 mM and 0.04 to 0.5 mM of melatonin were obtained applying the two techniques, respectively. The differential pulse mode was successfully applied to the determination of melatonin in commercial tablets containing about three-folds of vitamin B6 without previous separation. The same technique was also used for melatonin determination in human serum with acceptable accuracy.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    ABO BLOOD GROUPS IN CORRELATION WITH HYPERLIPIDEMIA, DIABETES MELLITUS TYPE II AND ESSENTIAL HYPERTENSION

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    Objectives: There are associations between ABO blood groups and systemic diseases. So we aim to explore any associations among ABO blood groupwith hyperlipidemia; diabetes mellitus (DM) type II, and essential hypertension.Methods: A total of 800 subjects were recruited. Patients groups were subdivided into hyperlipidemia group (n=100), DM type II group (n=160),and hypertension group (n=166). Fasting blood sample was collected and plasma samples used for measuring of 2, 3-dinor-6-keto-prostaglandinF1α (PGF1α), 11-dehydro-thromboxane (TX) B2, insulin, triglycerides (TGs), total cholesterol (Tc), high-density lipoprotein cholesterol (HDL-C),prothrombin time (PT), activated partial PT (aPPT), blood group type, random blood glucose level, and body mass index (BMI) were also determined.Results: Blood Group A demonstrates a significant elevation in insulin, random blood sugar (RBS), Tc, TGs, and low-density lipoprotein (LDL)/HDLratio and shows a significant decrease in prostacyclin. Blood group B demonstrates a significant elevation in TXB, Tc, TGs, and LDL/HDL ratio andshows a significant decrease in PT. Blood group AB demonstrates a significant elevation in PT, and prostacyclin and shows a significant decrease ininsulin, RBS, Tc, TGs, and LDL/HDL. Blood group O demonstrates a significant elevation in PT, and prostacyclin and shows a significant decrease inTXB2, Tc, TGs, and LDL/HDL ratio.2Conclusions: Blood group AB is protective against hyperlipidemia, diabetes, thrombosis, and hypertension, blood group O is protective againstcardiovascular diseases while blood group B followed by A are risk factors for hypertension and blood group A is a risk factor for diabetes. Thesefindings are establishing the ethnic-dependent correlation of ABO groups and studied diseases.Keywords: Hyperlipidemia, DM type II, Hypertension, Thrombosis, ABO blood groups

    Exploring the English Language Teachers’ Attitudes Towards the Use of Pedagogical Dictionaries in their Classes (Sudanese Perspective)

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    The dictionary should always be present in language education. It is the tool with which EFL teachers can effectively perform teaching tasks in their classes. Good teachers should take on the habit of consulting their dictionaries to assimilate the lexical, syntactical, phonological, morphological, etymological and more other features of one word or expression that a good dictionary can provide. This paper is investigating the attitudes of English language teachers in the use of this important teaching aid. It is an additional viewpoint from EL teachers in four Sudanese State Universities on the use of dictionary in their classes. The findings of this research might be of significance to other researchers, teachers, language learners and textbook designers; and the results may be applicable in many similar EFL environments round the globe.

    Voltammetric determination of melatonin in tablet dosage forms and human serum

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    The electrochemical oxidation of melatonin is studied in Britton-Robinson buffer in the pH range 2.2-11.8 by cyclic voltammetry at glassy carbon electrode. Three irreversible, diffusion-controlled oxidation peaks were obtained. The utility of using differential pulse and square wave techniques for determination of melatonin was examined. Different parameters affecting the peak current were analylzed and at optimum conditions, linear calibration plots from 0.02-0.5 mM and 0.04 to 0.5 mM of melatonin were obtained applying the two techniques, respectively. The differential pulse mode was successfully applied to the determination of melatonin in commercial tablets containing about three-folds of vitamin B6 without previous separation. The same technique was also used for melatonin determination in human serum with acceptable accuracy.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    COMBINED USE OF HYALURONIC ACID WITH NANO-BIOACTIVE GLASS ENHANCED BIOCEMENT BASED SILICATE STIMULATED BONE REGENERATIVE CAPACITY IN TIBIAL BONE DEFECTS OF RABBITS: IN-VIVO STUDY

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    An ideal biomaterial for bone regeneration is a longstanding quest nowadays. This study aimed to evaluate the osteogenic potentiality of nano-bioactive glass enhanced biocement based silicate with or without hyaluronic acid seeded in rabbits’ tibial bone defects. For this, 24 male rabbits with two 5 mm defects (1 defect per tibia) were divided into three equal groups. Among the predefined three groups, for the rabbits of group 1(control) bone defects were left untreated while for the members of group 2 defects received nano-bioactive glass enhanced biocement based silicate cement, and group 3 defects received nano-bioactive glass cement mixed with hyaluronic acid. Animals of each group were divided equally for euthanization after 3 and 6 weeks. Bone specimens were processed and examined histologically with histomorphometrically analysis of new bone area percentage. The bone defects in group 3 showed significantly improved osseous healing histologically as compared to the group 1&2. The morphometric analysis also revealed a significant increase in the new bone area percentage in group 3 as compared to the group 1 and 2 (P < 0.05). The results of the present study can be concluded that bone defects could be treated with nano-bioactive glass and hyaluronic acid cement. Although, nano-bioactive glass alone was capable of bone regeneration the combination of both had significant regenerative capacity

    Validity of sphenoid ostium in relation to posterior wall of maxillary sinus by computed tomography

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    Background: Sphenoid sinus is the most inaccessible paranasal sinus, enclosed within the sphenoid bone and intimately related to numerous vital neural and vascular structures. Anatomic variation of the sphenoid sinus is well documented and may complicate surgery in such a place.Objective: To assess the reliability of preoperative computed tomography (CT) in determination of the distance between the posterior wall of maxillary sinus (PWMS) and the sphenoid sinus ostium (SSO) in the coronal plane.Patients and methods: This was a prospective study of the distance between the SSO and the PWMS in the coronal plane, which was measured both radiologically in preoperative CT and intraoperatively during endoscopic sinus surgery for patients in need for middle meatal antrostomy and sphenoid sinusotomy at the same side. Distances obtained by both techniques have been tested for the degree of correlation. Number of the included patients was 25.Results: Forty four nasal sides were included in the study. The mean distance between the sphenoid sinus ostium and posterior wall of maxillary sinus in the coronal plane was 6.6 ± 1.8 mm when measured by preoperative CT and 6.9 ± 1.9 mm when measured directly during surgery. No significant difference was found between the mean distances measured by both techniques (p = 0.246) with good agreement between them (r = 0.864).Conclusion: Preoperative CT may be a reliable tool to preoperatively determine the difference in depth between the PWMS and the SSO
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