363 research outputs found

    SENSITIVE SPECTROPHOTOMETRIC ASSAY OF MUSCARINIC RECEPTOR ANTAGONIST TOLTERODINE TARTRATE IN BULK DRUG AND PHARMACEUTICAL FORMULATIONS

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    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

    Early Cerebrovascular Silent Changes in Long-Standing End-Stage Renal Disease Patients on Hemodialysis Value of Adding Advanced Unenhanced MRI Sequences to Imaging Protocols

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    Background: End-Stage Renal Disease (ESRD) patients on hemodialysis suffered from many central and peripheral neurological insults. Aim of the work:This study aimed to assess the value of using MRA, MRV, and SWAN sequences in early visualization of the silent cerebrovascular complications in those patients. Patients and Methods: Our study was conducted on forty-five patients with well-documented ESRD on regular hemodialysis for more than 5 years with no neurological manifestation, all undergone unenhanced MRI, DWI with ADC and measuring the ADC value, SWAN, MRA, and MRV. Results: we found that 11% of cases have acute infarction at the basal ganglia region. 36.7% of patients are diagnosed with intracerebral hemorrhage, only 26.7% of them are seen by the conventional MRI, and 16.7% of cases showed microbleeds on SWAN with normal conventional MRI. The sensitivity and specificity of SWAN with ADC value to detect brain hemorrhage are 100% and 88.8% respectively. Conclusion: Visualization of cerebrovascular complications such as infarction, hemorrhage, atherosclerosis, and arterial and venous occlusion using DWI with ADC, MRA, MRV, and SWAN and is very useful in early management and better prognosis of ESRD patients even with silent complications that don’t give up symptoms with high sensitivity and specificity of SWAN in early detection of hemorrhage and microbleeds

    Micro-encapsulation of asphalt rejuvenators using melamine-formaldehyde

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    Asphalt pavement roads are exposed to traffic loading and natural elements such as rain, sunlight and oxidation, which result in decreasing their relaxation capabilities and the initiation of cracks. Innovative maintenance techniques such as developing microcapsules with rejuvenators have emerged in order to reverse the aging process in asphalt binder. The objectives of this study were to assess the effectiveness of an asphalt rejuvenator to reverse the aging process in asphalt binder and to develop a microencapsulation procedure for the tested asphalt rejuvenator. Properties such as size, shell thickness and morphology of the prepared microcapsules were evaluated by varying the production parameters, i.e. agitation rate, heating temperature, and Ethyl Methyl Acrylate (EMA) concentration. Three binder types were considered in the experimental program, two virgin asphalt binders that were aged in the laboratory and a binder extracted from Reclaimed Asphalt Pavement (RAP). Based on the results of the experimental program, it was concluded that the binder Performance Grade (PG) 70-22 was partially restored at both high and low temperature grades with the use of the rejuvenator. In contrast, the low temperature grade of the binder PG 76-22 and the high temperature grade of the RAP binder were restored with the use of the tested rejuvenator product. Microcapsules containing the rejuvenator were synthesized and a characterization process was conducted based on microcapsule properties such as diameter, shell thickness and morphology of the prepared microcapsules

    Assessment of seminal plasma free amino acids among fertile men

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    Abstract Background:Amino acids can elevate sperm count, motility, and morphology. Increasing the availability of these amino acids can help to improve male fertility certain foods can help to improve sperm parameters. This is due to the high concentration of specific amino acids. There are many amino acids involved in the production, development and maintenance of sperm. Aims:assessment of seminal plasma free amino acids among fertile men. Patients and methods: this study done on 50 fertile menassessment of free amino acids in their seminal plasma, Semen analyses were done and amino acids measured in seminal plasma using H.P.L C. Results:The median and range of their semen analysis parameters were :volume 2(3-3),liquefaction time 10(10-15), sperm concentration 60(50-75)million / ml ,total sperm motility80(80-80) %, abnormal sperm35(30-40),viability 67.5(60-80)%the range of seminal plasma leucine was(1.68-1.87),isoleucine (1.22-1.31),valine(0.33-0.53)tyrosine, (1.11-1.22),phenylalanine (0.79-0.89) ,histidine (1.28-1.51) ,Tryptophan (0.26-0.36). Conclusions:Assessment of seminal plasma amino acids is very helpful in evaluation of male fertility

    Economic Analysis of Stand-Alone Hybrid Wind/PV/Diesel Water Pumping System: A Case Study in Egypt

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    The design and evaluation of a stand-alone hybrid renewable energy system for pumping underground water for small farm irrigation is presented. Given environmental conditions, system specifications and daily load demand data, the optimal size of main system components is obtained using a sizing algorithm. Different renewable energy systems are compared using yearly simulations, on hourly base via specialized commercial software simulation packages PVSYST and HOMER, to simulate the system performance and to reach the optimum configurations based on the objective criteria. The criteria used in economic optimization are the net present cost and the cost of energy, with the percent of the capacity shortage. The following systems can be compared: PV only, PV with horizontal axis wind turbine, PV with vertical axis wind turbine, and PV with horizontal axis wind turbine and diesel generator and diesel generator only. The simulation also was carried out for different load patterns for optimum operation. The study was illustrated for climatic conditions of an isolated area in El-Tour City, Sinai, Egypt. The installed 3.42 kW PV water pumping system for irrigation purposes in the same site was also described

    Rheological properties of asphalt binder modified with recycled asphalt materials and light-activated self-healing polymers

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    Ultraviolet (UV), light-activated, self-healing polymers are an emerging technology that was proposed to enhance the elastic behavior of asphalt binder, while improving its self-healing properties. The objective of this study was to evaluate the effects of self-healing polymer on the rheological properties of binder blends prepared with or without recycled asphalt materials. Binder blends were prepared with two different binders (PG 67-22 and PG 70-22M), with or without recycled asphalt materials, and 5% self-healing polymer (Oxetane-substituted Chitosan-Polyurethane). High-Pressure Gel Permeation Chromatography (HP-GPC) results showed an increase in High Molecular Weight (HMW) components in the binder with an increase in stiffness through the addition of recycled materials. A further increase was observed with the addition of self-healing polymer. Fourier Transform Infrared Spectroscopy (FTIR) confirmed High-Pressure Gel Permeation Chromatography (HP-GPC) results with an increase in the carbonyl index. Furthermore, the addition of recycled materials led to an increase in the high-temperature grade and the low-temperature grade of the binder blends, while the self-healing polymer did not have a significant effect on the PG-grade. Overall, the addition of self-healing polymer led to an increase in stiffness and an improvement in the rutting performance, while it did not have a positive effect on low-temperature cracking performance. For unmodified binder (PG 67-22), self-healing polymer incorporation improved the elastic and fatigue cracking properties of the binder. However, when it was added to a polymer-modified binder (PG 70-22M) and/or binder blends containing recycled asphalt materials, the potential of this material was low to negative on the low temperature and fatigue cracking performances

    Induction of cryptic antifungal pulicatin derivatives from <i>Pantoea agglomerans</i> by microbial co-culture

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    Microbial co-culture or mixed fermentation proved to be an efficient strategy to expand chemical diversity by the induction of cryptic biosynthetic pathways, and in many cases led to the production of new antimicrobial agents. In the current study, we report a rare example of the induction of silent/cryptic bacterial biosynthetic pathway by the co-culture of Durum wheat plant roots-associated bacterium Pantoea aggolomerans and date palm leaves-derived fungus Penicillium citrinum. The initial co-culture indicated a clear fungal growth inhibition which was confirmed by the promising antifungal activity of the co-culture total extract against Pc. LC-HRMS chemical profiling demonstrated a huge suppression in the production of secondary metabolites (SMs) of axenic cultures of both species with the emergence of new metabolites which were dereplicated as a series of siderophores. Large-scale co-culture fermentation led to the isolation of two new pulicatin derivatives together with six known metabolites which were characterised using HRESIMS and NMR analyses. During the in vitro antimicrobial evaluation of the isolated compounds, pulicatin H (2) exhibited the strongest antifungal activity against Pc, followed by aeruginaldehyde (1) and pulicatin F (4), hence explaining the initial growth suppression of Pc in the co-culture environment

    A comparative study of life cycle carbon emissions and embodied energy between sun-dried bricks and fired clay bricks

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    Publisher's version (útgefin grein)This study presents a comparison of the life cycle carbon emission (LCCO2) and embodied energy calculation between two kinds of bricks, sun-dried and fired clay, as means of evaluating the energy and climate impact of each brick type and the economics of production. Focus is paid to the differences across the whole production chain between sun-dried clay bricks, which represent the traditional norm, and fired clay bricks, which are the most widely-used walling materials in conventional buildings. A case study was carried out in Dakhla Oasis in the Western Desert of Egypt. The results of this study show that if sun-dried bricks are used instead of fired bricks, a reduction of up to 5907 kg CO₂e (in CO₂ emissions) and 5305 MJ of embodied energy for every1000 bricks produced could be achieved. The paper concludes by offering alternative scenarios for brick-making and suggestions for improving sun-dried brick production. The methodology used in this study contributes to the development of an investigative-comparative way to assess choices between building materials. It also intends to help inform local homeowners and building practitioners not only in Egypt, but also globally, about resource depletion, energy consumption, and harmful emissions from fired industrial bricks as a common building construction material.We would like to acknowledge Dr. Bernhard Steubing for his guidance on the applicability of using SimaPro in the Egyptian context and Dr. Andr? Stephan for his comments on an early draft of this study. Special thanks to Mr. Saber Osman for his swift response and help with technical reports on the Egyptian Brick Factory GHG Reduction Project and Eng. Baher El- Sharaawy for his help with data from the Egyptian GIS unit and CAPMAS. Thanks to Dr. Ahmed Abdelmontaleb for the discussion on LCA for the brick industry in Egypt. Sincere gratitude to Eng. Jaber Aboelela, Architect Zeiad Amer and Architect Yasser Abdallah for their kind help with providing information on brick production in Egypt.Peer Reviewe

    Enhancing land cover classification in remote sensing imagery using an optimal deep learning model

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    The land cover classification process, accomplished through Remote Sensing Imagery (RSI), exploits advanced Machine Learning (ML) approaches to classify different types of land cover within the geographical area, captured by the RS method. The model distinguishes various types of land cover under different classes, such as agricultural fields, water bodies, urban areas, forests, etc. based on the patterns present in these images. The application of Deep Learning (DL)-based land cover classification technique in RSI revolutionizes the accuracy and efficiency of land cover mapping. By leveraging the abilities of Deep Neural Networks (DNNs) namely, Convolutional Neural Networks (CNN) or Recurrent Neural Networks (RNN), the technology can autonomously learn spatial and spectral features inherent to the RSI. The current study presents an Improved Sand Cat Swarm Optimization with Deep Learning-based Land Cover Classification (ISCSODL-LCC) approach on the RSIs. The main objective of the proposed method is to efficiently classify the dissimilar land cover types within the geographical area, pictured by remote sensing models. The ISCSODL-LCC technique utilizes advanced machine learning methods by employing the Squeeze-Excitation ResNet (SE-ResNet) model for feature extraction and the Stacked Gated Recurrent Unit (SGRU) mechanism for land cover classification. Since ‘manual hyperparameter tuning’ is an erroneous and laborious task, the AIMS Mathematics Volume 9, Issue 1, 140–159. hyperparameter selection is accomplished with the help of the Reptile Search Algorithm (RSA). The simulation analysis was conducted upon the ISCSODL-LCC model using two benchmark datasets and the results established the superior performance of the proposed model. The simulation values infer better outcomes of the ISCSODL-LCC method over other techniques with the maximum accuracy values such as 97.92% and 99.14% under India Pines and Pavia University datasets, respectively

    An ex vivocystic fibrosis model recapitulates key clinical aspects of chronic Staphylococcus aureus infection

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    Staphylococcus aureus is one of the most prevalent organisms isolated from the airways of people with cystic fibrosis (CF), predominantly early in life. Yet its role in the pathology of lung disease is poorly understood. Clinical studies are limited in scope by age and health of participants and in vitro studies are not always able to accurately recapitulate chronic disease characteristics such as the development of small colony variants. Further, animal models also do not fully represent features of clinical disease: in particular, mice are not readily colonized by S. aureus and when infection is established it leads to the formation of abscesses, a phenomenon almost never observed in the human CF lung. Here, we present details of the development of an existing ex vivo pig lung model of CF infection to investigate the growth of S. aureus. We show that S. aureus is able to establish infection and demonstrates clinically significant characteristics including small colony variant phenotype, increased antibiotic tolerance and preferential localisation in mucus. Tissue invasion and the formation of abscesses were not observed, in line with clinical data
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