Affiner votre recherche
Résultats 4361-4370 de 7,292
Association between ambient temperature and ambulance dispatch: a systematic review and meta-analysis Texte intégral
2022
Xu, Er | Li, Yanni | Li, Tingting | Li, Qing
Previous studies have quantified the associations between ambient temperature and dispatch of ambulances, but the conclusions are still controversial. Therefore, a systematic review and meta-analysis were conducted to summarize all the current evidence. A systematic review of published literature was undertaken to characterize the effect of temperature on ambulance dispatch. We completed the literature search by the end of January 5, 2022. The pooled estimates for different temperature exposures were calculated using a random effects model. Differences among temperature pooled estimates were determined using subgroup analysis. This study was registered with PROSPERO under the number CRD42021284434. This is the first meta-analysis investigating the association between temperature and ambulance dispatch. A total of 25 studies were eligible for this study. The overall increased risks of high temperature, expressed as relative risks, were 1.734 (95% CI: 1.481–2.031). Subgroup analysis found that for the study using daily mean temperature, the high temperature increased the risk of ambulance dispatch by 15.2% (RR = 1.152, 95%CI: 1.081–1.228). In the ambulance dispatch of all-cause subgroups, the RR was 1.179 (95% CI: 1.085–1.282). The results also reported a significant association between low temperature and ambulance dispatch (RR = 1.130, 95% CI: 1.052–1.213). In the subgroup, the RR for cardiovascular disease was 1.209 (95% CI: 1.033–1.414), and respiratory disease was 1.126 (95% CI: 1.012–1.253). Sensitivity analysis indicated that the results were robust, and no obvious publication bias was observed. High temperature and low temperature are important factors influencing the dispatch of ambulances. These findings help improve the understanding of temperature effect on ambulance dispatch, demonstrating the need to consider wider surveillance of acute health outcomes in different environments.
Afficher plus [+] Moins [-]Sunlight-induced enhanced photocatalytic reduction of chromium (VI) and photocatalytic degradation of methylene blue dye and ciprofloxacin antibiotic by Sn3O4/SnS2 nanocomposite Texte intégral
2022
Kumar, Gandharve | Dutta, Raj Kumar
Detection of residual organic and inorganic species in water bodies, including drinking water, has led to developing strategies for their removal. Here, we report a very efficient method of removing Cr(VI), organic dye, and antibiotic from water using a type-II heterojunction based on Sn₃O₄/SnS₂ solar photocatalyst. The toxic Cr(VI) species are reduced by photocatalytic methodology, while methylene blue (MB) dye and ciprofloxacin (CIP) antibiotics are removed by photocatalytic degradation. The structural, compositional, morphological, and optical properties of the hydrothermally synthesized photocatalyst have been studied. Under sunlight exposure, more than 99.9% of Cr(VI) is reduced within 60 min at a reaction rate of 0.066 min⁻¹. While 99.6% of MB and 90% of CIP degradation are achieved in 90 min and 120 min, corresponding to photocatalytic degradation rates of 0.043 min⁻¹ and 0.019 min⁻¹, respectively. The total organic carbon after degradation corresponded to 85.1% for MB and 72.4% for CIP mineralization. The observed photocatalytic degradation is attributed to in situ generation of reactive oxygen species (ROS), e.g., superoxide radicals and hydroxyl radicals. The role of ROS towards photocatalytic degradation of MB and CIP, respectively, was confirmed from ROS scavenging studies. The MB and CIP degradation mechanism has been discussed by analyzing their degradation products.
Afficher plus [+] Moins [-]Preparation of hydrothermally solidified materials from waste cathode ray tube panel glass for construction applications Texte intégral
2022
Zhang, Jing | Xu, Qingbo | Wang, Haiyang | Li, Shunyi
Solidification of cathode ray tube (CRT) panel glass was carried out using a hydrothermal processing method. In this way, the glass powder was first compacted in a mold at 20 MPa, and then hydrothermally cured in an autoclave under saturated steam pressure at 200 ℃ for 6 h. The CRT panel glass was then hydrothermally solidified by the formation of tobermorite (Ca₅Si₆O₁₆(OH)₂·4H₂O), which was encouraged by the addition of slaked lime (Ca(OH)₂). The strength of solidified specimen heavily depended on the amount of tobermorite formed, with higher concentrations of tobermorite producing commensurately greater mechanical strength. With the addition of Ca(OH)₂ at 20–30% by mass, the specimen achieved a bending strength of approximately 16 MPa, which was sufficiently great for using as a construction material. As such, there is cause to believe that the hydrothermal processing method used here may have great potential for resource utilization of CRT panel glass, and the performance of the product is suitable for use as building materials.
Afficher plus [+] Moins [-]Iron oxide nanoparticles embedded in organic microparticles from Yerba Mate useful for remediation of textile wastewater through a photo-Fenton treatment: Ilex paraguariensis as a platform of environmental interest – Part 1 Texte intégral
2022
Monje, Dany Santiago | Ruiz, Orlando Simón | Valencia, Gloria Cristina | Mercado, D Fabio
Seven composites of iron oxide nanoparticles embedded in organic microparticles mediated by Cu(II) were synthesized using yerba mate (Ilex paraguariensis) dry leaf extract as precipitant, capping agent, and dispersant medium, using different Cu/Fe molar ratios. A thorough characterization of the particles by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis-mass spectrometry (TGA-MS), Fourier transform infrared spectrometer (FTIR), and atomic absorption-spectrometry (AA) indicates that all materials have spheric-like morphology with nanoparticles composed by metal oxide phases embedded into organic microparticles. Interestingly, this organic matter is proposed to play an important role in the solids’ photocatalytic activity in a photo-Fenton reaction, in which iron photo-leaching was elucidated, and a mechanism through ligand-to-metal charge transfer processes was proposed. All materials showed catalytic activity in the methyl orange elimination, achieving discolorations up to 96% in 2 h under UV irradiation at 375 nm. An experimental correlation between all samples’ UV/Vis spectra and their performances for methyl orange discoloration was observed. This process opens a landscape very interesting for the use of agroindustrial residues for green synthesis of metal oxide nanomaterials and their use and understanding of organo-metallic systems participation in Fenton-based processes.
Afficher plus [+] Moins [-]Effect of substrate properties and phosphorus supply on facilitating the uptake of rare earth elements (REE) in mixed culture cropping systems of Hordeum vulgare, Lupinus albus and Lupinus angustifolius Texte intégral
2022
Monei, Nthati | Hitch, Michael | Heim, Juliane | Pourret, Olivier | Heilmeier, Hermann | Wiche, Oliver
This study presents how phosphate (P) availability and intercropping may influence the migration of rare earth elements (REEs) in legume–grass associations. In a replacement model, Hordeum vulgare was intercropped with 11% Lupinus albus and 11% Lupinus angustifolius. They were cultivated on two substrates, A (pH = 7.8) and B (pH = 6.6), and treated with 1.5 g P m⁻² or 3 g P m⁻². Simultaneously, a greenhouse experiment was conducted to quantify carboxylate release. There, one group of L. albus and L. angustifolius was supplied with either 200 µmol L⁻¹ P or 20 µmol L⁻¹ P. L. albus released higher amounts of carboxylates at low P supply than L. angustifolius, while L. angustifolius showed the opposite response. Plants cultivated on substrate B accumulated substantially higher amounts of nutrients and REE, compared to substrate A. Higher P supply did not influence the leaf and stem P concentrations of H. vulgare. Addition of P decreased REE accumulation in barley monocultures on alkaline soil A. However, when H. vulgare was cultivated in mixed culture with L. angustifolius on alkaline substrate A with high P supply, the accumulation of REE in H. vulgare significantly increased. Conversely, on acidic substrate B, intercropping with L. albus decreased REE accumulation in H. vulgare. Our findings suggest a predominant effect of soil properties on the soil–plant transfer of REEs. However, in plant communities and within a certain soil environment, interspecific root interactions determined by species-specific strategies related to P acquisition in concert with the plant’s nutrient supply impact REE fluxes between neighbouring plants.
Afficher plus [+] Moins [-]Semi-solid anaerobic co-digestion of source-separated fecal slag and food waste: focusing on methane production, ecological risk assessment, and quality evaluation as fertilizer Texte intégral
2022
Yusuf, Hamza Hassan | Pan, Xiaofang | Cai, Guanjing | Cai, Jiasheng | Huang, Xuewei | Ye, Zhi-Long
Toilet revolution is driven by the urgent need for solutions to improve sanitation and access to high-quality organic fertilizer for rural areas, which is tagged “resource recovery from human waste.” This study provides a possible solution via semi-solid anaerobic co-digestion (Aco-D) of source-separated fecal slag (SFS) and food waste (FW) (3:1). A comprehensive investigation of Aco-D at different inoculum/substrate ratios (ISR) was conducted. Results revealed that the reactor with ISR of 1:4 reached the highest methane yield (255.05 mL/gVS), which enhanced Methanosaetaceae, Methanomicrobiales, and Syntrophomonas. Additionally, the reactor with low feedstock (ISR of 1:2) showed higher removal efficiency of antibiotics (74.75%). The ecological risk of digestate decreased to an insignificant hazard quotient level, and the contents of nutrients and heavy metals were in line with the standard requirement for fertilizer. This study could serve as an alternative technology to support further research in SFS management and digestate utilization as fertilizer.
Afficher plus [+] Moins [-]Effects of the green supply chain management practices on firm performance and sustainable development Texte intégral
2022
Amjad, Ahmad | Abbass, Kashif | Hussain, Yasir | Khan, Farina | Sadiq, Shahzad
The idea of sustainable development and green supply chain management is considered at the underlying stage in the research and academic fields, particularly in the rising economies of Asia. This research investigates the persuasive force of the firm’s green supply chain management practices with the mediating part of the competitiveness and investment recovery. Data was collected from the 12 ISO 9001 and ISO 14001 leather industries based in Pakistan. We distributed the 350 questionnaires at 12 leather industries, and the questionnaire was also transferred on Google Forms, and 50 questionnaire mail to different individuals who work in leather industries of other cities of Pakistan; out of 350 questionnaires, 183 were filled, and the remaining questionnaires were incomplete, and out of 50 emails, we get the response of 33 emails, and evaluated the model of this study by using the partial least square structural equation modeling PLS-SEM. We interact with the employees of leather industries and try to understand how they are following the green practices in their firms. This research uses resource dependence theory as the theoretical base. This study elaborates how the organization’s behavior is affected by the external resources of the corporation. The actual outcomes uncover that green supply chain management activities positively impacting the firm’s performance, where competitiveness and investment recovery play a mediating role among intra-organizational green practices.
Afficher plus [+] Moins [-]Mitotic and chromosomal effects induced for biosynthesized nanoparticles from three mediators on Allium cepa root cells Texte intégral
2022
Beatriz Andrioli, Nancy | Mendoza, Grace Stephany Solano | Fernández, Jorge Gastón | Ferramola, María Isabel Sanz
The genotoxicity of biogenic silver nanoparticles (AgNPs) obtained from three microbial mediators was assessed using the Allium cepa assay. Three clusters were differentiated for the highest frequency of end points of clastogenicity (stick-ends, fragments and bridges), end points of missegregation (C-metaphases and disorder anaphases), and lowest frequency of all the end points. In these clusters, the treatments were grouped respectively as I) positive control (GSF); II) silver nanoparticles form Aspergillus niger (AgNPs-An); and III) silver nanoparticles from both Cryptococcus laurentii (AgNPs-Cl) and Rhodotorula glutinis (AgNPs-Rg), Ag + , and negative control (NC). These results were in according to the principal component analisys (PCA) where treatments were associated to each component of the genotoxic effects. The statistical comparative analysis of the mitotic index (IM) and the abnormal mitosis frequency (AM) indicated that both GSF and AgNPsAn induce significant genotoxic effect. Low genotoxic effects were attributed to AgNPs-Cl and AgNPs-Rg, but mitogenic stimuli, similar to that obtained by the silver ions Ag + , were observed. Results suggested that different features of biogenic nanoparticles such as composition, size, and coating may be involved in the different cytological responses of the meristematic cells.
Afficher plus [+] Moins [-]Synthesizing urbanization and carbon emissions in Africa: how viable is environmental sustainability amid the quest for economic growth in a globalized world? Texte intégral
2022
Erdoğan, Savaş | Onifade, Stephen Taiwo | Altuntaş, Mehmet | Bekun, Festus Victor
Global emission statistics show that Africa is among the least carbon-emitting continents. However, the rising drive for economic growth amid urbanization and globalization in recent years has continued to attract the attention of policymakers to the attendant potential environmental risks. Hence, using robust empirical techniques, this study examines the impacts of increasing urbanization alongside its interactions with energy portfolios on environmental prospects of 15 selected African countries including the most urbanized and leading oil producers in the continent of Africa. The results of the analysis produced insightful implications for achieving both environmental and economic sustainability for the understudied countries. Firstly, the trio of urbanization, economic globalization, and income levels aggravate environmental degradation among these countries as they were found to be essential drivers of carbon emission levels over the understudied period (1990–2015). Secondly, while urbanization significantly poses threat to environmental sustainability, the evidence obtained regarding its interaction with energy portfolios of the understudied countries differs. The significant detrimental environmental impacts of the interaction between urbanization and energy portfolios were only confirmed in the context of fossil energy consumption among the countries, while renewables exist as a significant decarbonization channel within the framework of the increasing level of urbanization among the countries. Thirdly, the study upholds the EKC conjecture. Hence, policymakers and authorities in Africa should capitalize on maximizing the benefits of the huge renewable resource potentials on the continent through adequate investments in green energy technologies for urban infrastructures toward the realization of sustainable development goals (SDGs 11 and 13).
Afficher plus [+] Moins [-]Anthropogenic climate change drives melting of glaciers in the Himalaya Texte intégral
2022
Romshoo, Shakil Ahmad | Murtaza, Khalid Omar | Shah, Waheed | Ramzan, Tawseef | Ameen, Ummer | Bhat, Mustafa Hameed
The Himalayan glaciers provide water to a large population in south Asia for a variety of purposes and ecosystem services. As a result, regional monitoring of glacier melting and identification of the drivers are important for understanding and predicting future cryospheric melting trends. Using multi-date satellite images from 2000 to 2020, we investigated the shrinkage, snout retreat, thickness changes, mass loss and velocity changes of 77 glaciers in the Drass basin, western Himalaya, India. During this period, the total glacier cover has shrunk by 5.31 ± 0.33 km². The snout retreat ranged from 30 to 430 m (mean 155 ± 9.58 m). Debris cover had a significant impact on glacier melting, with clean glaciers losing ~ 5% more than debris-covered glaciers (~ 2%). The average thickness change and mass loss of glacier have been − 1.27 ± 0.37 and − 1.08 ± 0.31 m w.e.a⁻¹, respectively. Because of the continuous melting and the consequent mass loss, average glacier velocity has reduced from 21.35 ± 3.3 m a⁻¹ in 2000 to 16.68 ± 1.9 m a⁻¹ by 2020. During the observation period, the concentration of greenhouse gases (GHGs), black carbon (BC) and other pollutants from vehicular traffic near the glaciers increased significantly. Increasing temperatures, caused by a significant increase in GHGs, black carbon and other pollutants in the atmosphere, are driving glacier melting in the study area. If the current trend continues in the future, the Himalayan glaciers may disappear entirely, having a significant impact on regional water supplies, hydrological processes, ecosystem services and transboundary water sharing.
Afficher plus [+] Moins [-]