19 research outputs found

    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

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

    Get PDF
    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

    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

    Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021

    Get PDF
    Background: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions

    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

    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

    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

    No full text
    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

    No full text
    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
    corecore