584 research outputs found

    Equilibrium And Kinetic Study On The Biosorption Of Trypan Blue From Aqueous Solutions Using Avocado Seed Powder

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    This research aims to investigate the removal of trypan blue dye from aqueous solutions by employing ground avocado seeds powder, a low-cost biowaste adsorbent (biosorbent), under various experimental conditions. The effect of contact time, initial dye concentration, and adsorbent dose on dye removal were studied. The experimental kinetic data were fitted to pseudo-first order and pseudo-second-order kinetic models. Results imply that adsorption of trypan blue on the avocado seed adsorbent nicely followed the pseudo-second-order kinetic model. Equilibrium isotherms were analyzed by Langmuir and Freundlich isotherms, where Langmuir isotherm described the isotherm data with a high-correlation coefficient (R2=0.9948) closer to unity, and maximum adsorption capacity was found to be 19.3 mg g−1. The present study results substantiate that ground avocado seeds are a promising adsorbent for the removal of the dye trypan blue from industrial wastewater

    Removal Of Methylene Blue By Adsorption Of Water Hyacinth Derived Active Carbon Embedded With Cobalt Nanoparticles

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    In this research, active carbon-based catalyst synthesis and characterization were tested for potential catalysts to be used in dye removal of methylene blue (MB). Water hyacinth is one of the major problems that is facing humankind and especially here in Egypt. One of the implications of industrial activities is environmental pollution. Dyes used in the production of textiles, paper, and clothes are one of the major pollutants. The waste of those dyes discharged into water supplies without treatment or with ineffective treatment harmfully impacts the environment. In this research, the treatment is implemented using active carbon-based catalysts using embedded nanoparticles. This leads to a huge increase in the adsorbent\u27s surface area, also increasing the adsorbent efficiency. The activated carbon was derived from water hyacinth that grows near the Nile River. Water hyacinth has many practical uses as it can absorb heavy metals like lead and dyes. Water hyacinth was converted into activated carbon through carbonization. Different dyes were used with different contact times in fixed conditions

    Histidine substitution in the most flexible fragments of firefly luciferase modifies its thermal stability.

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    Molecular dynamics (MD) at two temperatures of 300 and 340 K identified two histidine residues, His461 and His489, in the most flexible regions of firefly luciferase, a light emitting enzyme. We therefore designed four protein mutants H461D, H489K, H489D and H489M to investigate their enzyme kinetic and thermodynamic stability changes. Substitution of His461 by aspartate (H461D) decreased ATP binding affinity, reduced the melting temperature of protein by around 25 degrees C and shifted its optimum temperature of activity to 10 degrees C. In line with the common feature of psychrophilic enzymes, the MD data showed that the overall flexibility of H461D was relatively high at low temperature, probably due to a decrease in the number of salt bridges around the mutation site. On the other hand, substitution of His489 by aspartate (H489D) introduced a new salt bridge between the C-terminal and N-terminal domains and increased protein rigidity but only slightly improved its thermal stability. Similar changes were observed for H489K and, to a lesser degree, H489M mutations. Based on our results we conclude that the MD simulation-based rational substitution of histidines by salt-bridge forming residues can modulate conformational dynamics in luciferase and shift its optimal temperature activity

    Dilated cardiomyopathy as a rare presentation of the pulmonary sequestration: A case report with aberrant vessel from aorta to left lower pulmonary lobe

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    Late onset non-ischemic cardiomyopathy is a rare manifestation of the presence of aberrant vessel from descending thoracic aorta to left lower lobe of lung. This congenital anomaly is associated with pulmonary sequestration. Our case was a 23-year-old male who was under observation since the age of 19 years for evaluation of shortness of breath, functional class II. He had history of professional athletic training and he denied consumption of any compound. Ejection fraction had deteriorated during three years from 45�50 to 40 and left ventricular size increased from normal size to mild enlargement. Cardiac computed tomography showed presence of aberrant artery from descending aorta to left lower pulmonary lobe with pulmonary sequestration. His cardiac function improved after successful coil embolization of aberrant vessel. In conclusion, pulmonary sequestration and aberrant pulmonary supply from aorta should be considered as a rare cause of dilated cardiomyopathy which can be reversible by proper intervention. © 2019 Japanese College of Cardiolog

    Modeling effects of voltage dependent properties of the cardiac muscarinic receptor on human sinus node function

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    The cardiac muscarinic receptor (M2R) regulates heart rate, in part, by modulating the ace-tylcholine (ACh) activated K⁺ current IK,ACh_{K,ACh} through dissociation of G-proteins, that in turn activate KACh_{ ACh} channels. Recently, M2Rs were noted to exhibit intrinsic voltage sensitivity, i.e. their affinity for ligands varies in a voltage dependent manner. The voltage sensitivity of M2R implies that the affinity for Ach (and thus the Ach effect) varies throughout the time course of a cardiac electrical cycle. The aim of this study was to investigate the contribution of M2R voltage sensitivity to the rate and shape of the human sinus node action potentials in physiological and pathophysiological conditions. We developed a Markovian model of the IK,ACh_{K,ACh} modulation by voltage and integrated it into a computational model of human sinus node. We performed simulations with the integrated model varying Ach concentration and voltage sensitivity. Low Ach exerted a larger effect on IK,ACh_{K,ACh} at hyperpolarized versus depolarized membrane voltages. This led to a slowing of the pacemaker rate due to an attenuated slope of phase 4 depolarization with only marginal effect on action potential duration and amplitude. We also simulated the theoretical effects of genetic variants that alter the voltage sensitivity of M2R. Modest negative shifts in voltage sensitivity, predicted to increase the affinity of the receptor for ACh, slowed the rate of phase 4 depolarization and slowed heart rate, while modest positive shifts increased heart rate. These simulations support our hypothesis that altered M2R voltage sensitivity contributes to disease and provide a novel mechanistic foundation to study clinical disorders such as atrial fibrillation and inappropriate sinus tachycardia

    Morphological Effects of Combined Systemic Administration of Fluoxetine and Sildenafil in the Murine Hippocampus

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    We examined the effects of fluoxetine, a selective serotonin re-uptake inhibitor, of sildenafil, a phosphodiesterase-5 (PDE5) inhibitor, and of combined administration of these agents on morphometric characteristics of principal cells of the murine hippocampus. Fluoxetine (5 mg/kg), sildenafil (2 mg/kg), or a combination of these drugs in the above doses were administered i.p. daily for 2 weeks to male mice. Hippocampal sections (5 mm thick) were stained with hematoxylin/eosin. Both drugs and their combination evoked no considerable changes in the dimensions of pyramidal cells in the CA1 and CA2 areas and in the dentate gyrus (DG), except for a trend toward some decrease of this parameter after fluoxetine injections in the CA1 area. Combined administration of fluoxetine and sildenafil provided significant decreases in the density of pyramidal neurons (their mean number per 10 mm of the slice) in the CA1 area and DG. Isolated administration of fluoxetine resulted in significant but less intense decreases in the density of principal cells in the CA2 area and DG. Possible mechanisms of the effects of the mentioned drugs are discussed. Further studies of interaction between fluoxetine and sildenafil in their effects on morphological and physiological properties of cells in different subregions of the hippocampus are recommended.Ми досліджували вплив флуоксетину (селективного інгібітора зворотного захвату серотоніну), силденафілу (інгібітора фосфодіестерази-5, PDE5) та їх сукупного введення на морфометричні характеристики основних (пірамідних) клітин гіпокампа мишей. Флуоксетин (5 мг/кг), силденафіл (2 мг/кг) або комбінація цих агентів у зазначених дозах уводилися самцям мишей внутрішньоочеревинно щоденно протягом двох тижнів. Зрізи гіпокампа завтовшки 5 мкм забарвлювали гематоксиліном та еозином. Обидві речовини та їх комбінація не викликали значних змін розмірів пірамідний нейронів у зонах CA1, CA2 та зубчастої звивини (ЗЗ), певна тенденція до зменшення зазначеного параметра спостерігалася після ін’єкцій флуоксетину в зоні CA1. Сукупна дія флуоксетину та силденафілу призводила до істотного зменшення щільності пірамідних нейронів (їх середньої кількості з розрахунку на 10 мкм зрізу) у зоні CA1 та ЗЗ. Обговорюються можливі механізми ефектів згаданих агентів. Доцільними є подальші дослідження особливостей взаємодії флуоксетину та силденафілу на морфологічні та фізіологічні характеристики клітин у різних підрозділах гіпокампа

    Morphological Effects of Combined Systemic Administration of Fluoxetine and Sildenafil in the Murine Hippocampus

    No full text
    We examined the effects of fluoxetine, a selective serotonin re-uptake inhibitor, of sildenafil, a phosphodiesterase-5 (PDE5) inhibitor, and of combined administration of these agents on morphometric characteristics of principal cells of the murine hippocampus. Fluoxetine (5 mg/kg), sildenafil (2 mg/kg), or a combination of these drugs in the above doses were administered i.p. daily for 2 weeks to male mice. Hippocampal sections (5 mm thick) were stained with hematoxylin/eosin. Both drugs and their combination evoked no considerable changes in the dimensions of pyramidal cells in the CA1 and CA2 areas and in the dentate gyrus (DG), except for a trend toward some decrease of this parameter after fluoxetine injections in the CA1 area. Combined administration of fluoxetine and sildenafil provided significant decreases in the density of pyramidal neurons (their mean number per 10 mm of the slice) in the CA1 area and DG. Isolated administration of fluoxetine resulted in significant but less intense decreases in the density of principal cells in the CA2 area and DG. Possible mechanisms of the effects of the mentioned drugs are discussed. Further studies of interaction between fluoxetine and sildenafil in their effects on morphological and physiological properties of cells in different subregions of the hippocampus are recommended.Ми досліджували вплив флуоксетину (селективного інгібітора зворотного захвату серотоніну), силденафілу (інгібітора фосфодіестерази-5, PDE5) та їх сукупного введення на морфометричні характеристики основних (пірамідних) клітин гіпокампа мишей. Флуоксетин (5 мг/кг), силденафіл (2 мг/кг) або комбінація цих агентів у зазначених дозах уводилися самцям мишей внутрішньоочеревинно щоденно протягом двох тижнів. Зрізи гіпокампа завтовшки 5 мкм забарвлювали гематоксиліном та еозином. Обидві речовини та їх комбінація не викликали значних змін розмірів пірамідний нейронів у зонах CA1, CA2 та зубчастої звивини (ЗЗ), певна тенденція до зменшення зазначеного параметра спостерігалася після ін’єкцій флуоксетину в зоні CA1. Сукупна дія флуоксетину та силденафілу призводила до істотного зменшення щільності пірамідних нейронів (їх середньої кількості з розрахунку на 10 мкм зрізу) у зоні CA1 та ЗЗ. Обговорюються можливі механізми ефектів згаданих агентів. Доцільними є подальші дослідження особливостей взаємодії флуоксетину та силденафілу на морфологічні та фізіологічні характеристики клітин у різних підрозділах гіпокампа

    In-hospital and six-month outcomes of elderly patients undergoing primary percutaneous coronary intervention for acute st-elevation myocardial infarction

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    BACKGROUND: Elderly patients constitute a rapidly growing proportion of the population, and hence the increasing rises in the number of patients with ST-segment-elevation myocardial infarction (STEMI). Primary percutaneous coronary intervention (PCI), which is now established as the preferred reperfusion strategy in STEMI patients, has been inadequately investigated in this high-risk group. The aim of the present study was to investigate the in- hospital and 6-month outcomes of primary PCI in elderly patients (� 75 years) with STEMI. METHODS: A total of 100 elderly patients with STEMI including those with cardiogenic shock were included. Primary PCI procedures were performed in a tertiary referral center between 2009 and 2014. In-hospital and 6-month outcomes of patients were recorded and analyzed. RESULTS: The average age of the patients was 79.6 ± 3.8 years (range = 75-90 years) and 27.0 were women. Cardiovascular risk factors and prior events were common. Nearly, half of the patients had three-vessel disease and the left anterior descending artery (LAD) was the most common infarct-related artery. The presence of cardiogenic shock but not the other variables was associated with less anatomic and procedural success (P < 0.001). It was also the major independent predictors of 6-month mortality in the patients aged � 75 years, hazard ratio (HR) = 8.02; 95% confidence interval (CI): 1.75-25.97, P < 0.001. In-hospital mortality was 2.4% in the patients without and 83.0% in those with cardiogenic shock. CONCLUSION: Primary PCI in aged patients could be associated with low complication rates and improved survival if performed in high-volume centers with experienced operators. Considering the very high rate of mortality in patients with cardiogenic shock, there should be measures to treat these patients before the onset of hemodynamic instability. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved

    Reducing radiation exposure in second-generation cryoballoon ablation without compromising clinical outcome

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    Purpose: Pulmonary vein isolation (PVI) using cryoballoon (CB) ablation is associated with an increased radiation exposure compared with radiofrequency ablation. Previous studies showed that radiation exposure in CB PVI can be reduced by optimizing the fluoroscopy protocol without comprising acute efficacy and safety. We evaluated the mid-term outcome of a modified fluoroscopy protocol in patients undergoing CB PVI. Methods: The study population comprised 90 consecutive patients who underwent second-generation CB-based PVI. The first 46 patients underwent CB PVI with conventional fl

    Transcatheter closure of coronary artery fistulae: A literature review

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    Coronary artery fistulae (CAFs) are anomalous connections that bypass the myocardial capillary bed between 1 or more coronary arteries and other cardiac chambers or other vessels. These fistulae are usually asymptomatic and are, thus, diagnosed incidentally. However, larger CAFs can cause various symptoms such as angina, exertional dyspnea, syncope, palpitation, and even sudden cardiac death. Treatment options include surgical closure and percutaneous transcatheter closure (TCC) with comparable safety and efficacy. The choice of device in TCC depends on the anatomic characteristics of the CAF, the age and size of the patient, the size of the occluded vessel, the appropriate size of the catheter to be used, and the tortuosity of the catheter course to reach the intended point. Herein, we present 4 cases treated via TCC and then offer an in-depth discussion regarding this coronary artery anomaly. © 2020, Tech Science Press. All rights reserved
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