18 research outputs found

    Prevalence and antibiotic resistance of uropathogens in children with urinary tract infections referring to Abuzar hospital in Ahvaz

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    Urinary tract infection (UTI) is a prevalent disease among children. This study is an attempt to find the bacterial agents of UTI and antibiotic resistance in children. A descriptive cross-sectional study was carried out on 1316 clinical samples of children at Abuzar Hospital in Ahvaz that had positive urine culture. The strains were determined through biochemical tests and differential culture media. The pattern of antibiotic resistance of the studied strains was determined by the disk diffusion method. Out of the 1316 children surveyed, 821 were girls and 495 were boys. The most isolated strains from urine cultures were Escherichia coli (57.52%) followed by Enterococcus (12.15%). E. coli isolates demonstrated the highest resistance to ampicillin (57.06%) and amikacin was recognized as the most effective antibiotic with a sensitivity of 91.94%. E. coli was the most common causative agent of UTI in children. Amikacin was recognized as the appropriate choice against urinary tract pathogens. Because, in different regions and over time, the frequency distribution of antibiotic resistance varies, it is recommended to carry out periodic monitoring of antibiotic resistance for infection control

    Levofloxacin loaded poly (ethylene oxide)-chitosan/quercetin loaded poly (D,L-lactide-co-glycolide) core-shell electrospun nanofibers for burn wound healing

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    This study developed a new burn wound dressing based on core-shell nanofibers that co-deliver antibiotic and antioxidant drugs. For this purpose, poly(ethylene oxide) (PEO)-chitosan (CS)/poly(D,L-lactide-co-glycolide) (PLGA) core-shell nanofibers were fabricated through co-axial electrospinning technique. Antibiotic levofloxacin (LEV) and antioxidant quercetin (QS) were incorporated into the core and shell parts of PEO-CS/PLGA nanofibers, respectively. The drugs could bond to the polymer chains through hydrogen bonding, leading to their steady release for 168 h. An in vitro drug release study showed a burst effect followed by sustained release of LEV and QS from the nanofibers due to the Fickian diffusion. The NIH 3T3 fibroblast cell viability of the drug loaded core-shell nanofibers was comparable to that in the control (tissue culture polystyrene) implying biocompatibility of the nanofibers and their cell supportive role. However, there was no significant difference in cell viability between the drug loaded and drug free core-shell nanofibers. According to in vivo experiments, PEO-CS-LEV/PLGA-QS core-shell nanofibers could accelerate the healing process of a burn wound compared to a sterile gauze. Thanks to the synergistic therapeutic effect of LEV and QS, a significantly higher wound closure rate was recorded for the drug loaded core-shell nanofibrous dressing than the drug free nanofibers and control. Conclusively, PEO-CS-LEV/PLGA-QS core-shell nanofibers were shown to be a promising wound healing material that could drive the healing cascade through local co-delivery of LEV and QS to burn wounds

    Levofloxacin loaded poly (ethylene oxide)-chitosan/quercetin loaded poly (D,L-lactide-co-glycolide) core-shell electrospun nanofibers for burn wound healing

    Get PDF
    This study developed a new burn wound dressing based on core-shell nanofibers that co-deliver antibiotic and antioxidant drugs. For this purpose, poly(ethylene oxide) (PEO)-chitosan (CS)/poly(D,L-lactide-co-glycolide) (PLGA) core-shell nanofibers were fabricated through co-axial electrospinning technique. Antibiotic levofloxacin (LEV) and antioxidant quercetin (QS) were incorporated into the core and shell parts of PEO-CS/PLGA nanofibers, respectively. The drugs could bond to the polymer chains through hydrogen bonding, leading to their steady release for 168 h. An in vitro drug release study showed a burst effect followed by sustained release of LEV and QS from the nanofibers due to the Fickian diffusion. The NIH 3T3 fibroblast cell viability of the drug loaded core-shell nanofibers was comparable to that in the control (tissue culture polystyrene) implying biocompatibility of the nanofibers and their cell supportive role. However, there was no significant difference in cell viability between the drug loaded and drug free core-shell nanofibers. According to in vivo experiments, PEO-CS-LEV/PLGA-QS core-shell nanofibers could accelerate the healing process of a burn wound compared to a sterile gauze. Thanks to the synergistic therapeutic effect of LEV and QS, a significantly higher wound closure rate was recorded for the drug loaded core-shell nanofibrous dressing than the drug free nanofibers and control. Conclusively, PEO-CS-LEV/PLGA-QS core-shell nanofibers were shown to be a promising wound healing material that could drive the healing cascade through local co-delivery of LEV and QS to burn wounds

    Improvement of Cycle Stability for Graphite-Based Lithium-Ion Batteries via Usage of Phenyl Methanesulfonate as an Electrolyte Additive

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    In this work, phenyl methanesulfonate (PMS) is evaluated as an additive to enhance the cyclic stability of lithium-ion batteries (LIBs) based on a graphite electrode. According to the theoretical results obtained from density functional theory (DFT) calculations, PMS possesses a lower reduction potential compared to the cyclic carbonate electrolyte solvent. Hence, this compound is foreseen to be reduced before ethylene carbonate (EC) and form a solid electrolyte interphase (SEI) layer on the graphite electrode. The cyclic stability of Li/graphite battery is promoted considerably by adding a low dose of PMS to the electrolyte. The capacity retention of the Li/graphite half-cell is incredibly improved to about 100% after 35 cycles at room temperature. The results acquired from the electrochemical and surface characterization tests corroborate that an electrolyte with PMS is capable of forming a thinner SEI layer compared to the electrolyte devoid of an additive, which can dramatically lessen the interfacial resistance. Moreover, the results show that the graphite sheets are disguised under a myriad of PMS reductive deposits, which can neutralize the catalytic activity of prismatic surfaces

    Phenyl Vinylsulfonate, a Novel Electrolyte Additive to Improve Electrochemical Performance of Lithium-Ion Batteries

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    Irreversible capacity fading, originating from the formation of the solid electrolyte interphase (SEI), is a common challenge encountered in lithium-ion batteries (LIBs) containing an electrolyte based on ethylene carbonate (EC). In this research, phenyl vinyl sulfonate (PVS) is examined as a novel electrolyte additive to mitigate this issue and subsequently enhance the cyclic stability of LIBs. As evidenced by density functional theory (DFT) calculations, PVS has a higher reduction potential than that of EC, which is in accordance with the cyclic voltammetry (CV) measurements. Accordingly, the PVS-containing electrolyte demonstrated a reduction peak at ~1.9 V, which was higher than that of the electrolyte without an additive (at ~1.7 V). In contrast to the SEI derived from the reference electrolyte, the one built-in PVS-containing electrolyte was capable of completely inhibiting the electrolyte reduction. In terms of the Raman spectroscopy and electrochemical impedance spectroscopy (EIS) analysis, SEI formation as the result of PVS reduction can lead to less structural disorder in the graphite electrode; the battery with the additive showed less interfacial and charge transfer resistance. The Li/graphite cell with 1 wt % of PVS delivered capacity retention much higher than that of its counterpart without the additive after 35 cycles at 1 C

    Phenyl Vinylsulfonate, a Novel Electrolyte Additive to Improve Electrochemical Performance of Lithium-Ion Batteries

    No full text
    Irreversible capacity fading, originating from the formation of the solid electrolyte interphase (SEI), is a common challenge encountered in lithium-ion batteries (LIBs) containing an electrolyte based on ethylene carbonate (EC). In this research, phenyl vinyl sulfonate (PVS) is examined as a novel electrolyte additive to mitigate this issue and subsequently enhance the cyclic stability of LIBs. As evidenced by density functional theory (DFT) calculations, PVS has a higher reduction potential than that of EC, which is in accordance with the cyclic voltammetry (CV) measurements. Accordingly, the PVS-containing electrolyte demonstrated a reduction peak at ~1.9 V, which was higher than that of the electrolyte without an additive (at ~1.7 V). In contrast to the SEI derived from the reference electrolyte, the one built-in PVS-containing electrolyte was capable of completely inhibiting the electrolyte reduction. In terms of the Raman spectroscopy and electrochemical impedance spectroscopy (EIS) analysis, SEI formation as the result of PVS reduction can lead to less structural disorder in the graphite electrode; the battery with the additive showed less interfacial and charge transfer resistance. The Li/graphite cell with 1 wt % of PVS delivered capacity retention much higher than that of its counterpart without the additive after 35 cycles at 1 C

    Improvement of Cycle Stability for Graphite-Based Lithium-Ion Batteries via Usage of Phenyl Methanesulfonate as an Electrolyte Additive

    No full text
    In this work, phenyl methanesulfonate (PMS) is evaluated as an additive to enhance the cyclic stability of lithium-ion batteries (LIBs) based on a graphite electrode. According to the theoretical results obtained from density functional theory (DFT) calculations, PMS possesses a lower reduction potential compared to the cyclic carbonate electrolyte solvent. Hence, this compound is foreseen to be reduced before ethylene carbonate (EC) and form a solid electrolyte interphase (SEI) layer on the graphite electrode. The cyclic stability of Li/graphite battery is promoted considerably by adding a low dose of PMS to the electrolyte. The capacity retention of the Li/graphite half-cell is incredibly improved to about 100% after 35 cycles at room temperature. The results acquired from the electrochemical and surface characterization tests corroborate that an electrolyte with PMS is capable of forming a thinner SEI layer compared to the electrolyte devoid of an additive, which can dramatically lessen the interfacial resistance. Moreover, the results show that the graphite sheets are disguised under a myriad of PMS reductive deposits, which can neutralize the catalytic activity of prismatic surfaces

    Evaluation of ceramic water filters’ performance and analysis of managerial insights by SWOT matrix

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    Filtration is a crucial step in the water treatment process, typically preceding disinfection. Filters trap microorganisms and suspended solids, reducing their amount in the environment. The latest technology in filtration is ceramic filters, and in this study, the performance of silicon carbide ceramic filters (SIC) is evaluated. These filters were installed at three different locations within a water treatment plant (entrance storage, raw water, and backwash water), and changes in physical and chemical water parameters were measured. Results indicate high efficiency in turbidity removal, effectively clarifying volatile suspended solids (VSS) and fixed suspended solids (FSS). The turbidity removal efficiency was 99% for entrance storage and 65% for raw water. The SWOT (Strengths, Weaknesses, Opportunities, and Threats) matrix was used to analyse the results of the SIC and highlight its strengths, weaknesses, opportunities, and threats

    Application of Decision-Making Techniques for Prioritizing Water Treatment Technology in Flood Events: A  Preventive Crisis Management in the Czech Republic

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    Flood is one of the phenomena that threaten people's life and property, which occurs every year in developed and developing countries [1]. Meanwhile, rapid response to water quality problems during this natural disaster is one of the most critical factors of an Early-Warning System (EWS). Due to the change in the river network and the washing of urban and rural environments, the quality of water in flood is significantly reduced, and the residents face the problem of water supply during this period [2]. This paper presents a fast response framework for selecting the best water treatment techniques in unusual pollution loads of urban floods based on water qualitative analysis and methods of Game Theory (GT) as decision-making techniques. The main goal of this study is to provide a framework for improving drinking water supply services during flood risk management in the Czech Republic. To achieve the fast water treatment technologies, Ordered Weighted Averaging (OWA), mulTi-noRmalization mUlti-distance aSsessmenT (TRUST) and VIekriterijumsko KOmpromisno Rangiranje (VIKOR) computations as Multi Criteria Decision Making (MCDM) were applied. In fact, based on this structure, an operational model for the Czech Republic as per the Preventive Crisis Management (PCM) approach has been expressed as the primary outcome of this investigation. The results demonstrated that mobile membrane technologies could have higher efficiency than other methods. However, from the economic aspect, many options can be utilized in different scenarios according to the managerial opinions

    A comprehensive platform for air pollution control system operation in smart cities of developing countries: a case study of Tehran

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    Controlling air pollution in megacities is crucial from both a health and environmental perspective. Air pollution is a pervasive problem in these densely populated cities and must be effectively managed to promote sustainability. This study presents a framework for the intelligent management of air pollution control systems in developing nations. The framework was developed through the use of an expert agreement model involving five managers from Tehran. The results indicate that the Decision Support System (DSS) is equipped with calibrated sensors for monitoring air quality. Additionally, the concentration of air pollutants can be determined through the application of machine learning algorithms and the analysis of historical data. Rapid response methods are then applied to mitigate the acute and chronic effects of air pollution. The DSS also incorporates citizens' feedback to evaluate the effectiveness of air pollution control measures. Implementing this model in developing nations' smart cities can help achieve several of the United Nations' Sustainable Development Goals (SDGs), such as good health and well-being, sustainable cities and communities, climate action, and life on land
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