959 research outputs found
Prevalence of Metallo-β-Lactamase producing Pseudomonas aeruginosa in wound infections in Duhok city, Iraq
Background: Pseudomonas aeruginosa is common pathogen causing nosocomial infection. Acquired drug resistance and Metallo-β-lactamases (MBL) production have recently emerged as one of the most worrisome resistance mechanism that hydrolyze all beta-lactam antibiotics including penicillins, cephalosporins and carbapenems, with the exception of aztreonam. The aim was to find out the prevalence of multi drug resistant (MDR) and Metallo-β-lactamase (MBL) positive isolates of P. aeruginosa in wounds samples which are a serious concern.Methods: Pseudomonas aeruginosa strains were obtained by standard isolation and identification techniques from 307 wound samples of hospital. Strains were then subjected to susceptibility testing for anti-pseudomonas drugs as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Carbapenems resistant strains were selected for the detection of MBL enzyme production by disc potentiation test. Production of MBL was confirmed by enhancement of inhibition zone around imipenem and meropenem discs impregnated with EDTA, as compared to discs without EDTA.Results: Amongst the 71 isolates of P. aeruginosa, 62(87.3%) isolate were imipenem-sensitive, while 9(12.7%) isolates were found to be imipenem resistant and MBL producers. Very high resistance to antibiotics was recorded amongst MBL producers’ P. aeruginosa compared with non-MBL imipenem-sensitive strains.Conclusion: Study indicates that, surveillance for the detection of MBL is necessary. The rapid dissemination of MBL producers is worrisome and necessitates the implementation of proper and judicious selection of antibiotics especially carbapenem.
CLOUD POINT EXTRACTION, PRECONCENRATION AND SPECTROPHOTOMETRIC DETERMINATION OF COBALT IN WATER SAMPLES
Objective: A new cloud point extraction (CPE) method was developed for pre concentration of trace cobalt (II) in water samples.Methods: The method is based on the complexation reaction of Co (II) with 2-(benzothiazolyl azo)-4-nitrophenol reagent (BTANP) at pH 7.0 and micelle-mediated extraction using the nonionic surfactant Triton X-114 of the complex.Results: The enriched analyte in the surfactant-rich phase was diluted with methanol and the cobalt content was determined by spectrophotometry at 549 nm. The optimum conditions (e. g. pH, reagent and surfactant concentrations, and temperature and centrifugation times) were evaluated and optimized. The proposed CPE method showed linear calibration within the range 10–300 ng/ml of Co(II) and the limit of detection of the method was 1.5 ng/ml with a pre concentration factor of 50. The relative standard deviation (RSD) was found to be 1.20% (N = 6). The interference effect of some cations and anions was also studied.Conclusion: The proposed method has been successfully applied to the determination of Co(II) in water samples with a recovery from spiked samples in the range of 96.60–98.70%.Â
A Comparative Study of Adaptive Neuro Fuzzy Inference System and Artificial Neural Networks for Predicting Groundwater Hydraulic Head in an Arid Region
يهدف هذا البحث إلى تطوير نموذج تنبؤي لتقدير منسوب المياه الجوفية في منطقة سفوان-الزبير باستخدام نظام الاستدلال العصبي الضبابي المكيف (ANFIS). تمثل هذه المنطقة الجزء الجنوبي من الصحراء العراقية، وهي منطقة قاحلة ذات موارد مائية محدودة. تم توليد البيانات المطلوبة لبناء نموذج ANFIS باستخدام نموذج MODFLOW V.5.3)). حيث تمت معايرة نموذج MODFLOW اعتمادا على القياسات الحقلية خلال سنة واحدة. ولد نموذج MODFLOW (3797) قيمة للمنسوب الهيدروليكي خلال كل شهر. استخدمت 70 ٪ من هذه القيم (2658 عينة) للتدريب، و30 ٪ منها (1139 عينة) في عملية التحقق. تم مقارنة دقة نماذج ANFIS مع دراسة سابقة معتمدة على تقنية الشبكة العصبية الاصطناعية (ANN). كانت متغيرات الادخال من المناسيب الهيدروليكية المتعاقبة ومعدلات تغذية المياه الجوفية. لا توجد زيادة كبيرة في دقة التقدير عند إضافة متغير إدخال آخر (معدل تغذية المياه الجوفية)، لأن مقدار هذا المتغير قليل جدًا، لذلك كان تأثيره على النتائج غير محسوس. توضح مقارنة ANFIS وANN أن نموذج ANFIS هو أفضل من ANN في مرحلة التحقق. يمكن ان يعزا ذلك الى ان نموذج ANFIS يجمع بين أساسيات المنطق الضبابي والشبكات العصبية؛ وبالتالي يمكن استخدام خصائصها في إطار واحد. يمكن استنتاج أن نموذج ANFIS أكثر ملائمة من نموذج ANN للتنبؤ بالمنسوب الهيدروليكي للمياه الجوفية من بيانات المدخلات ذات الصلة.The aim of this research is to develop a predictive model to estimate the groundwater head in Safwan-Zubair area by using an adaptive neural fuzzy inference system (ANFIS). This area represents the southern sector of the Iraqi Desert, an arid region with scarce and limited resources. The data required for building the ANFIS model are generated using MODFLOW model (V.5.3). MODFLOW model was calibrated based on field measurements during one year. MODFLOW model generated (3797) hydraulic head values during each month. 70% of these values (2658 samples) was used for training, 30% of these values (1139 samples) was used for checking. The accuracy of the ANFIS models are compared with previous work based on artificial neural network (ANN) technique. Different combination of successive hydraulic heads and recharge rates of groundwater is used as input variables. There is no significant increase in the estimation accuracy when adding another input variable (recharge rate). Because the amount of this variable is very little, so its influence on the results was imperceptible. A comparison of ANFIS and ANN shows that the ANFIS model performs preferable than the ANN model on the checking phase. ANFIS model combines both fuzzy logic basics and neural networks; thus their properties can be utilized in one frame. It can be concluded, the ANFIS model appears to be more convenient than the ANN model for predicting groundwater hydraulic head from related input data
VALIDATED SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF MONTELUKAST SODIUM IN PURE AND DOSAGE FORMS USING N-BROMOSUCCINIMIDE AND DYES
Objective: Simple, sensitive, precise, reproducible and validated spectrophotometric methods have been developed for the quantification of montelukast sodium as leukotriene receptor antagonist drug, in pure and dosage forms (tablets).
Methods: The methods use N-bromosuccinimide (NBS) as an oxidant and three dyes, amaranth, methylene blue, and indigo carmine, as auxiliary reagents. The three methods are based on oxidation reaction of montelukast sodium with a known excess of N-bromosuccinimide (NBS) in acid medium, followed by determination of unreacted NBS by the reaction with a fixed amount of dyes, amaranth, methylene blue, and indigo carmine followed by the measurement of the absorbance at 520, 664 and 610 nm, respectively.
Results: Under the optimum conditions, linear relationships with good correlation coefficients (0.9993-0.9996) were found over the concentration ranges of 0.5-10, 1.0-12 and 0.5-8.0 µg/ml with a limit of detection (LOD) of 0.15, 0.3 and 0.14 µg/ml using amaranth, methylene blue, and indigo carmine methods, respectively. Intra-day and inter-day accuracy and precision of the methods have been evaluated. No interference was observed from the common tablet excipients.
Conclusion: The proposed methods were validated in accordance with ICH guidelines and successfully applied to the analysis of montelukast sodium in dosage forms (tablets). The reliability of the methods was further ascertained by performing recovery studies using the standard addition method. Statistical comparison of the results obtained by applying the proposed methods with those of the reported method by applying student’s t-test and F-test revealed good agreement
Effect of type of mixing water and sand on the physico–mechanical properties of magnesia cement masonry units
AbstractThis study has been conducted to investigate the influences of sand addition and mixing waters with different ratios on the physico-mechanical properties of magnesium oxychloride cement (MOC) masonry units. Three mixtures (M, MI and MII) were prepared to make magnesium oxychloride cement from the sand dunes as a filler material with some different additives. The mixture (M) was prepared by seawater instead of tap water in the mixing process, other mixtures (MI & MII) used drinking water. The physico-mechanical properties were studied in means of determination of bulk density, water absorption and compressive strength of the hardened MOC specimens cured in air at the lab ambient conditions for 3, 7, and 28days. It was recognized that the compressive strengths decreased with the increase of sand dunes content. The specimens of the all cured mixtures fulfilled superior properties compared with the required limits for concrete and limestone masonry units of a heavy density type. Also, it was found that using of the seawater leads to increase the physico-mechanical properties of the MOC specimens and can be used as mixing water in the manufacture of masonry units instead of the traditional drink water after ensuring of the other demanded governing properties
Interplay between personality traits and learning strategies:the missing link
Students with varying personality traits are likely to employ diverse learning and study strategies. However, this relationship has never been explored in the medical education context. This study’s aim was to explore the relationship between learning strategies and personality traits among medical students. This study was a cross-sectional study, and a quantitative approach was employed using two self-administered questionnaires: one to assess the personality traits from the Five-Factor Model (Conscientiousness, Neuroticism, Extraversion, Openness, and Agreeableness), and the other to assess 10 learning strategies (Anxiety, Attitude, Concentration, Information Processing, Motivation, Selecting Main Ideas, Self-Testing, Test Strategies, Time Management, and Using Academic Resources). A stratified random sampling technique was used to recruit medical students at Alfaisal University in the preclinical and clinical years (N = 309). Pearson correlation coefficient was used to measure the relationship between variables, and linear regression was used to evaluate how personality traits predicted learning strategy selection. Personality traits predicted the selection of learning strategies, especially Conscientiousness and Neuroticism. Conscientiousness showed a positive correlation with seven learning strategies and was the most important predictor of learning strategies students employ. Neuroticism correlations and predictions were negative. The other three traits showed weaker correlations. These correlations were between Extraversion and Using Academic Resources (r = 0.27), Information Processing (r = 0.23), and Attitude (r = 0.19); Openness and Information Processing (r = 0.29); and Agreeableness and Attitude (r = 0.29). All personality domains influence at least one learning strategy, especially Conscientiousness and Neuroticism. This study helps build a foundation for individualized coaching and mentorship in medical education. NEW & NOTEWORTHY This study aspires to build a foundation for individualized coaching and mentorship in medical education through utilizing personality traits to empower academic success. We demonstrate that all personality domains influence students’ selection of at least one learning strategy, especially Conscientiousness and Neuroticism
SENSITIVE SPECTROPHOTOMETRIC ASSAY OF MUSCARINIC RECEPTOR ANTAGONIST TOLTERODINE TARTRATE IN BULK DRUG AND PHARMACEUTICAL FORMULATIONS
Objective: Simple, sensitive, and accurate spectrophotometric methods have been developed for the assay of tolterodine tartrate (TOL) in bulk drugand pharmaceutical formulations.Methods: The proposed methods are based on oxidation reaction of TOL with a known excess of cerium(IV) ammonium sulfate as an oxidizing agentin acid medium followed by determination of unreacted oxidant by adding a fixed amount of dye, e.g., amaranth (AM), rhodamine 6G (Rh6G), andindigo carmine (IC) followed by measuring the absorbance at 520, 530, and 610 nm, respectively. The effect of experimental conditions was studiedand optimized.Results: The Beer's law was obeyed in the concentration ranges of 1.0-10, 1.0-12, and 0.5-9.0 μg/mL using AM, Rh6G, and IC dyes, respectively, witha correlation coefficient ≥0.9995. The calculated molar absorptivity values are 1.868×104, 1.008×104, and 1.623×104 L/mol/cm using AM, Rh6G, andIC dyes, respectively. The limits of detection and quantification were reported. Intraday and interday accuracy and precision of the methods have beenevaluated. No interference was observed from the additives.Conclusion: The proposed methods were successfully applied to the assay of TOL in tablets preparations, and the results were statistically comparedwith those of the reported method by applying Student's t-test and F-test. The reliability of the methods was further ascertained by performingrecovery studies using the standard addition method
Prophylactic use of carvedilol to prevent ventricular dysfunction in patients with cancer treated with doxorubicin
Objective:
Deterioration in ventricular function is often observed in patients treated with anthracyclines for cancer. There is a paucity of evidence on interventions that might provide cardio-protection. We investigated whether prophylactic use of carvedilol can prevent doxorubicin-induced cardiotoxicity and whether any observed effect is dose related.
Methods:
A prospective, randomized, double-blind study in patients treated with doxorubicin, comparing placebo (n = 38) with different doses of carvedilol [6.25 mg/day (n = 41), 12.5 mg/day (n = 38) or 25 mg/day (n = 37)]. The primary endpoint was the measured change in left ventricular ejection fraction (LVEF) from baseline to 6 months.
Results:
LVEF decreased from 62 ± 5% at baseline to 58 ± 7% at 6-months (p = 0.002) in patients assigned to placebo but no statistically significant changes were observed in any of the 3 carvedilol groups. At 6 months, only one of 116 patients (1%) assigned to carvedilol had an LVEF < 50% compared to four of the 38 assigned to placebo (11%), (p = 0.013). No significant differences were noted between carvedilol and placebo in terms of the development of diastolic dysfunction, clinically overt heart failure or death.
Conclusions:
Carvedilol might prevent deterioration in LVEF in cancer patients treated with doxorubicin. This effect may not be dose related within the studied range
GREEN VORTEX-ASSISTED IONIC LIQUID-BASED DISPERSIVE LIQUID-LIQUID MICROEXTRACTION FOR ENRICHMENT AND DETERMINATION OF CADMIUM AND LEAD IN WATER, VEGETABLES AND TOBACCO SAMPLES
Objective: An eco-friendly, simple and sensitive vortex-assisted ionic liquid-based dispersive liquid-liquid microextraction method (VA-IL-DLLµE) has been proposed to enrich and determine trace levels of cadmium (Cd2+ ) and lead (Pb2+ ) ions in water, vegetables and tobacco samples, prior to its FAAS determination.
Methods: The proposed method based on utilization of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for both ions after the complexation with 4,5-dihydroxy-3-phenylazo-2,7-naphthalenedisulfonic acid, disodium salt (Chromotrope 2R) at pH 6.5. The impact of different analytical parameters on microextraction efficiency was optimized.
Results: In the ranges of 1.0–300 and 2.0-400 μg/ml, the calibration graphs were linear. The limits of detection were 0.3 and 0.6 μg/ml for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 100. The relative standard deviation (RSD %)<3.0%, which indicates the proposed method has high precision.
Conclusion: The proposed VA-IL-DLLµE method was developed and applied for the estimation of Cd2+ and Pb2+ ion content in various water, vegetables and tobacco samples, and satisfactory results were obtained. The obtained recovery values showed good agreement with the certified values
Copper(II)-oxaloyldihydrazone complexes: Physico-chemical studies: Energy band gap and inhibition evaluation of free oxaloyldihydrazones toward the corrosion of copper metal in acidic medium
AbstractA series of oxaloyldihydrazone ligands were prepared essentially by the conventional condensation reaction between oxaloyldihydrazide and different aldehydes e.g., salicylaldehyde, 2-hydroxy-1-naphthaldehyde, 2-hydroxyacetophenone and 2-methoxybenzaldehyde in 1:2M ratio. The synthesized compounds were purified to give bis(salicylaldehyde)oxaloyldihydrazone (L1), bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone (L2), bis(2-hydroxyacetophenone)oxaloyldihydrazone (L3) and bis(2-methoxybenzaldehyde)oxaloyldihydrazone (L4). All the oxaloyldihydrazones (L1–L4) and their relevant solid copper(II) complexes have been isolated and characterized by various physicochemical techniques. The identity of the synthesized compounds has been ascertained on the basis of elemental analyses, spectral (UV–Vis, IR, ESR, mass, 1H NMR), magnetism and thermal (TG) measurements. The dihydrazones coordinate to the metal center forming binuclear complexes. Upon chelation, the metal center can form a trigonal distorted octahedral structure with L1 and pseudo tetrahedral configuration with L2 & L3 & L4. The optical band gap energy for all compounds underlies the range of semiconductor materials. The investigated ligands were assayed for their corrosion inhibitive and adsorptive properties on copper surface in 1M HCl solution using weight loss technique. The results pointed out that, the ligands have a plausible inhibition toward the corrosion of copper specimen. The adsorption reaction on copper surface was found to be spontaneous first order and agreed with physical adsorption mechanism. The adsorption data fitted well to Freundlich, Langmuir and Frumkin adsorption isotherms
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