Refinar búsqueda
Resultados 4501-4510 de 7,292
Effects of ambient air pollutants on hospital admissions and deaths for cardiovascular diseases: a time series analysis in Tehran Texto completo
2022
Motesaddi Zarandi, Saeed | Hadei, Mostafa | Hashemi, Seyed Saeed | Shahhosseini, Elahe | Hopke, Philip K. | Namvar, Zahra | Shahsavani, Abbas
Short-term exposures to air pollution have been associated with various adverse health effects. In this study, we investigated the associations between ambient air pollutants with the number of hospital admissions and mortality from cardiovascular diseases (CVDs). This time series study was conducted in Tehran for the years 2014–2017 (1220 day). We collected the ambient air pollutant concentration data from the regulatory monitoring stations. The health data were obtained from the Ministry of Health and Medical Education. A distributed lag non-linear model (DLNM) was used for the analyses. Total CVDs and ischemic heart disease (IHD) admissions were associated with CO for each 1 mg/m³ increase at lags of 6 and 7 days. Also, there was a positive association between total CVDs (RR 1.01; 1.001 to 1.03), IHD (RR 1.04; 1.006 to 1.07), and cerebrovascular diseases (RR 1.03; 1.005 to 1.07) mortality with SO₂ at a lag of 4 days. PM₂.₅ and PM₁₀ were associated with cerebrovascular disease admissions in females aged 16–65 years and 16 years and younger for each 10 µg/m³ increase, respectively. Short-term exposure to SO₂, NO₂, and CO was associated with hospital admissions and mortality for CVDs, IHD, cerebrovascular diseases, and other cardiovascular diseases at different lags. Moreover, females were more affected by ambient air pollutants than males in terms of their burden of CVDs. Therefore, identifying the likely harmful effects of pollutants given their current concentrations requires the planning and implementation of strategies to reduce air pollution.
Mostrar más [+] Menos [-]Removal of Hg2+ from desulfurization wastewater by tannin-immobilized graphene oxide Texto completo
2022
Chen, Heng | Liu, Fengjun | Cai, Chenjian | Wu, Hao | Yang, Linjun
A novel adsorbent consisting of tannic acid (TA) immobilized on graphene oxide (GO) was proposed and used to remove Hg²⁺ from desulfurization wastewater. The morphology and physicochemical properties of tannin-immobilized graphene oxide (TAIGO) were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The characterization results showed that TA was successfully immobilized on GO, and that new functional groups were introduced on TAIGO. The effects of contact time, adsorbent dose, pH, and ion components on removal efficiency were evaluated. The adsorption process was found to be complete within 15 min, and the removal efficiency increased with increasing adsorbent dosage. The pH value affected the protonation of TAIGO and the form of Hg²⁺ in wastewater. High concentrations of Cl⁻ and SO₃²⁻ hindered the adsorption performance, whereas SO₄²⁻ and cations had a negligible effect. In addition, the excellent economic benefits of TAIGO were analyzed in an economic evaluation, and the Hg²⁺ removal efficiency remained at 88% after three recycles. A pseudo-second-order kinetic model (R = 0.9995) was used to fit the adsorption process, and the oxygen-containing functional groups and chelation reaction played critical roles in adsorption. TAIGO is a low-cost adsorbent with high Hg²⁺ removal efficiency and could be further used in practical desulfurization wastewater.
Mostrar más [+] Menos [-]Novel biologically synthesized metal nanopowder from wastewater for dye removal application Texto completo
2022
Kumar, Manoj | Venugopal, Ajay Kumar Pottikkadavath | Pakshirajan, Kannan
A novel adsorbent based on metal sulfide nanoparticles (MeSNPs) was biologically synthesized from metallic wastewater and examined for azo dyes removal from aqueous solution in batch and continuous systems. The size of the MeSNPs was in the range of 8–10 nm, with an average specific surface area of 120.4 m²/g. Batch adsorption study was then carried out using Direct Red 80 (DR 80) and Mordant Blue 9 (MB 9) as the model azo dyes by varying MeSNPs dosage, contact time, pH, and initial dye concentration. More than 99% removal efficiency of both the dyes was achieved by using MeSNPs at the following optimum conditions: 200 mg dosage, pH 2, 6 min contact time, and 100 mg L⁻¹ initial dye concentration. The batch sorption isotherm results were described using the Sips model, with the maximum predicted capacity values of 143.7 and 198.3 mg of dye per gram of adsorbent for DR 80 and MB 9, respectively. Besides, the sorption kinetic data for both the dyes followed the pseudo-second-order rate. Furthermore, maximum desorption efficiency values of 93% for DR 80 and 97% for MB 9 were achieved using an aqueous solution of pH 12, thus indicating that the adsorbent can be regenerated and reused further. Dynamic adsorption of the dyes was studied using a fixed-bed column with the MeSNPs as a function of liquid flow rates. The results showed an increase in breakthrough time with a decline in the flow rates for both DR 80 and MB 9 and the breakthrough behavior was explained using Thomas, Clark, and Yoon-Nelson models.
Mostrar más [+] Menos [-]A game-theoretic approach to designing an optimal code of conduct program to promote supplier sustainability in a supply chain Texto completo
2022
Zāriʻī, Ḥamīd | Rasti-Barzoki, Morteza
In recent years, suppliers in developing countries face the challenge of their low technological and knowledge-related capabilities to enhance sustainability. In addition, buying firms cannot optimize the performance of the whole supply chain because the supplier sustainability practices are unobservable to them and to the public. These two challenges lead to the occurrence of several environmental and social scandals. These scandals pose serious economic and reputational consequences to supply chain members, especially buying firms. Given these challenges and using a sequential game-theoretic methodology, our contribution to the literature on supplier sustainability is to address the effects of supplier code of conduct (SCC) programs on different performance indicators of supply chains. Our analyses indicated that (a) an SCC program can mitigate the supply chain performance deficiencies created by the lack of the integrated optimization of the whole supply chain. Moreover, an SCC program can be superior to some common auditing programs initiated by buying firms. (b) In cases that the supplier’s capability is low or moderate, an SCC program provides a Pareto improvement in its sustainability level and the buying firm’s profit. (c) High consumer awareness threatens the buying firm’s survival in the market. Given this threat, an SCC program indirectly enhances the buying firm’s potential to survive. (d) Buying firms should lower their suppliers’ wholesale prices in exchange for a substantial investment in their suppliers’ capabilities, irrespective of whether or not an SCC program is initiated.
Mostrar más [+] Menos [-]Does energy use and economic growth allow for environmental sustainability? An empirical analysis of Pakistan Texto completo
2022
Mohsin, Muhammad | Naseem, Sobia | Sarfraz, Muddassar | Zia-UR-Rehman, Muhammad | Baig, Sajjad Ahmad
The rapid growth of environmental pollution and the destruction of eco-systems force every individual economy to focus on environmentally friendly economic development. This research explores economic growth, energy use, foreign direct investment, agriculture, industrialization, and urban population growth with environmental sustainability proxied as CO₂ emissions from 1971 to 2018. Econometric methods are employed for different purposes as the unit root for the stationary check. ARDL determines the long-run relationship, while the Decoupling Index examines the growing speed of variables and CO₂ emissions, and VECM has been used for short- and long-run causalities. The study’s findings confirm the long-run impact of all environmental pollution variables as ECM-1 is negatively significant. The short-run causality test shows CO₂ emissions because of economic growth (GDP = > CO₂ ≠ GDP), energy use (ENU = > CO₂ ≠ ENU), and foreign direct investment (FDI = > CO₂ ≠ FDI) at a 1% level. In contrast, CO₂ emissions are not the Granger cause of GDP, ENU, and FDI. Economic growth, energy use, and foreign direct investment will increase CO₂ emission, not vice versa. The study findings suggest that governments should move toward adopting green technology by implementation of green fiscal policies.
Mostrar más [+] Menos [-]Air pollution associated with cognitive decline by the mediating effects of sleep cycle disruption and changes in brain structure in adults Texto completo
2022
Lo, Chen-Chen | Liu, Wen-Te | Lu, Yueh-Hsun | Wu, Dean | Wu, Chih-Da | Chen, Ting-Chieh | Fang, Yu-Ting | Lo, Yu-Chun | Chen, You-Yin | Kang, Lo | Tsai, Cheng-Yu | Lee, Yueh-Lun | Chuang, Kai-Jen | Ho, Kin-Fai | Chang, T. Y. (Ta-Yuan) | Chuang, Hsiao-Chi
The effects of air pollution on sleep and dementia remain unclear. The objective of this study was to investigate the effects of air pollution on cognitive function as mediated by the sleep cycle. A cross-sectional study design was conducted to recruit 4866 subjects on which PSG had been performed. Fifty of them were further given a cognitive function evaluation by the MMSE and CASI as well as brain images by CT and MRI. Associations of 1-year air pollution parameters with sleep parameters, cognitive function, and brain structure were examined. We observed that O₃ was associated with a decrease in arousal, an increase in the N1 stage, and a decrease in the N2 stage of sleep. NO₂ was associated with an increase in the N1 stage, a decrease in the N2 stage, and an increase in REM. PM₂.₅ was associated with a decrease in the N1 stage, increases in the N2 and N3 stages, and a decrease in REM. The N1 and N2 stages were associated with cognitive decline, but REM was associated with an increase in cognitive function. The N1 stage was a mediator of the effects of PM₂.₅ on the concentration domain of the MMSE. O₃ was associated with an increase in the pars orbitalis volume of the left brain. NO₂ was associated with increases in the rostral middle frontal volume, supramarginal gyrus volume, and transverse temporal volume of the left brain, and the pars opercularis volume of the right brain. PM₂.₅ was associated with increases in the pars triangularis volume of the left brain and the fusiform thickness of the right brain. In conclusion, we observed that air pollution was associated with cognitive decline by mediating effects on the sleep cycle with changes in the brain structure in controlling executive, learning, and language functions in adults.
Mostrar más [+] Menos [-]Propolis efficacy on SARS-COV viruses: a review on antimicrobial activities and molecular simulations Texto completo
2022
Ghosh, Soumya | Al-Sharify, Zainab T. | Maleka, Mathabatha Frank | Onyeaka, Helen N. | Maleke, Maleke | Maolloum, Alhaji | Godoy, Liliana | Meskini, Maryam | Rami, Mina Rezghi | Ahmadi, Shabnam | Al-Najjar, Shahad Z. | Al-Sharify, Noor T. | Ahmed, Sura M. | Dehghani, Mohammad Hadi
This current study review provides a brief review of a natural bee product known as propolis and its relevance toward combating SARS-CoV viruses. Propolis has been utilized in medicinal products for centuries due to its excellent biological properties. These include anti-oxidant, immunomodulatory, anti-inflammatory, anti-viral, anti-fungal, and bactericidal activities. Furthermore, studies on molecular simulations show that flavonoids in propolis may reduce viral replication. While further research is needed to validate this theory, it has been observed that COVID-19 patients receiving propolis show earlier viral clearance, enhanced symptom recovery, quicker discharge from hospitals, and a reduced mortality rate relative to other patients. As a result, it appears that propolis could probably be useful in the treatment of SARS-CoV-2-infected patients. Therefore, this review sought to explore the natural properties of propolis and further evaluated past studies that investigated propolis as an alternative product for the treatment of COVID-19 symptoms. In addition, the review also highlights the possible mode of propolis action as well as molecular simulations of propolis compounds that may interact with the SARS-CoV-2 virus. The activity of propolis compounds in decreasing the impact of COVID-19-related comorbidities, the possible roles of such compounds as COVID-19 vaccine adjuvants, and the use of nutraceuticals in COVID-19 treatment, instead of pharmaceuticals, has also been discussed.
Mostrar más [+] Menos [-]Exposure characteristics of phthalate metabolites among the Zunyi cohort of pregnant women in Southwest China Texto completo
2022
Liao, Juan | Fang, Derong | Liu, Yijun | Xiong, Shimin | Wang, Xia | Tian, Yingkuan | Zhang, Haonan | An, Songlin | He, Caidie | Chen, Wei | Liu, Xiang | Wu, Nian | Tian, Kunming | Wang, Linglu | Zhang, Ya | Yuan, Hongyu | Zhang, Li | Li, Quan | Shen, Xubo | Zhou, Yuanzhong
Reported evidence has increasingly indicated that exposure to phthalates can cause adverse pregnancy outcomes. However, phthalate exposure levels among pregnant women remains unclear. We aimed to evaluate the concentrations and predictors of phthalate metabolites in urine samples of the ongoing Zunyi cohort of pregnant women from Southwest China. The urine samples were collected from 1003 pregnant women during their third trimester of pregnancy. The concentrations of nine phthalate metabolites in urine samples were then determined. Data on socio-demographic profiles of the participants, lifestyle during pregnancy, parity, and sampling season were collected using questionnaires. The detectable rate of phthalate metabolites ranged from 76 to 100%. On average, mono-butyl phthalate exhibited the highest median concentration (62.45 μg/L), while mono-benzyl phthalate exhibited the lowest median concentration (0.04 μg/L). Urine concentrations of phthalate metabolites were significantly higher in older, multiparous, higher body mass index, higher income, and passive smoking during pregnancy participants. The levels of low-molecular-weight phthalate metabolites were highest during the summer. The findings indicate the health of pregnant women and fetuses in Zunyi may be generally harmed by the high exposure of phthalate metabolites, especially by mono-n-butyl phthalate. In addition, phthalate metabolites present a demographic and seasonal differential distribution among the study population. Targeted measures to reduce phthalate exposure for high-risk pregnant women and during high-exposure seasons may have potential benefits for maternal and fetal health protection.
Mostrar más [+] Menos [-]Analysis on the spatio-temporal evolution and influencing factors of China’s grain production Texto completo
2022
Li, Shaoting | Zhang, Daojun | Xie, Yuan | Yang, Chao
The rapid economic development and climate change have accelerated the changes in China’s food production and have a potential impact on food security. In this paper, the grain sown area from 2001 to 2019 was selected to analyze the spatio-temporal evolution and driving factors of China’s grain production through spatial autocorrelation analysis and geographically weighted regression. Our findings were as follows: (1) From the perspective of time characteristics, China’s grain production from 2001 to 2019 experienced four stages, rapid decline, rapid growth, steady growth, and slow decline, although with an overall upward trend. (2) From the perspective of spatial characteristics, the overall spatial pattern had a significant positive correlation. The high values were mainly concentrated in Shandong, Anhui, and Jilin and moved to the northeast China as time went on. (3) In terms of influencing factors, the positive impact of agricultural labor force on the grain production gradually decreased, showing a decreasing trend from southwest to northeast. The promotion of agricultural mechanization on the grain production increased year by year, with the spatial distribution characteristics of high in the northeast and low in the southwest. Besides, the coefficient of water resources endowment was negative, showing a spatial distribution pattern of high north and low south.
Mostrar más [+] Menos [-]Synergistic effects of glyphosate- and 2,4-D-based pesticides mixtures on Rhinella arenarum larvae Texto completo
2022
Peluso, Julieta | Furió Lanuza, Agustina | Pérez Coll, Cristina S. | Aronzon, Carolina M.
Glyphosate and 2,4-D are two herbicides commonly used together. Since there is little information about the interactions between these pesticides, the aim of this study was to evaluate the single and joint lethal toxicity of the glyphosate-based herbicide (GBH) ATANOR® (43.8% of glyphosate, isopropylamine salt) and the 2,4-D-based herbicide (2,4-DBH) Así Max 50® (602000 mg/L of 2,4-D) on Rhinella arenarum larvae. Equitoxic and non-equitoxic mixtures were prepared according to the recommendation for their combination and analyzed with a fixed ratio design at different exposure times and levels of lethality (LC10, LC50, and LC90). GBH (504h-LC50=38.67 mg ae/L) was significantly more toxic than 2,4-DBH (504h-LC50=250.31 mg ae/L) and their toxicity was time-dependent. At 48h, the equitoxic mixture toxicity was additive and from the 96h was antagonistic at LC10 and LC50 effect level. The non-equitoxic mixture toxicity was additive at LC10 effect level from the 48h to the 168h, and synergistic from the 240h. At LC50 and LC90 effect level, the mixture interaction resulted synergistic for all exposure times. This is the first study to report the synergistic interactions between GBH and 2,4-DBH on amphibians, alerting about its negative impact on aquatic ecosystems.
Mostrar más [+] Menos [-]