خيارات البحث
النتائج 4581 - 4590 من 6,535
Association between noise exposure and diabetes: meta-analysis النص الكامل
2020
Wang, Huimin | Sun, Dawei | Wang, Boshen | Gao, Dengfeng | Zhou, Yanhua | Wang, Ning | Zhu, Baoli
Diabetes is one of the typical chronic diseases, and its incidence is related to many environmental factors. At present, there is no radical cure for diabetes, so the prevention of diabetes is particularly important. In order to effectively prevent the occurrence of diabetes, it is necessary to understand the conditions leading to the occurrence of diabetes. Current studies have shown that long-term exposure to noise will increase the risk of diabetes. Literature was retrieved from Pubmed and Web of Science. The relationship between noise exposure and diabetes published in the past 10 years was retrieved from the literature. Two researchers screened the literatures and extracted the data according to the inclusion and exclusion criteria. Endnote software was used to manage the literature, and NOS (Newcastle-Ottawa Scale) scale was used to evaluate the quality of the included literatures. Random effects meta-analysis was used to comprehensively evaluate the noise exposure of diabetic patients, and stata13.1 was used for data analysis. After adherence to strict inclusion and exclusion criteria, eight studies on the association between noise and diabetes were selected, including five cohort studies and three cross-sectional studies, with a total of 514,570 participants and 23,708 diabetics. The results showed that exposure to noise increased the risk of developing diabetes (OR = 1.08; 95% CI = 1.03 ~ 1.12). From the analysis of these selected articles, it can be seen that there is a positive correlation between noise and the occurrence of diabetes. As a result, it is necessary to strengthen routine blood tests for people who have been exposed to noise for a long time, especially those who have to be exposed to noise due to their occupations.
اظهر المزيد [+] اقل [-]Impacts of injection temperature on the CO2 injection capacity in the different sloping formations النص الكامل
2020
Jing, Jing | Zhou, Wei | Yang, Yanlin | Zuo, Lin | Tang, Zhonghua
The CO₂ injection capacity directly affects the CO₂ storage efficiency. Injection temperature and formation sloping degree affect the CO₂ injection capacity. Based on the actual geological conditions of the Shiqianfeng Formation in the Ordos Basin of China, a three-dimensional (3D) simulation model was established to evaluate pressure, temperature, CO₂ spatial distribution, and injection amount. A total of 17 simulation schemes were carried out using the TOUGH2–ECO2N fluid property module. The results showed that the injection temperature had a significant impact on the CO₂ injection capacity in the different sloping degree formations. Increasing the injection temperature resulted in increased formation pressure, CO₂ gas phase, dissolved phase, and total injection amount, while decreasing the CO₂ concentration, and the formation pressure changed obviously with the formation sloping degree. The larger the formation sloping degree was, the less the CO₂ injection amount. Higher injection temperature and smaller sloping degree formation were more favorable for CO₂ injection, and the CO₂ injection capacity was stronger, signaling that it should be selected to store CO₂ in the future.
اظهر المزيد [+] اقل [-]Preparation of high porosity biochar materials by template method: a review النص الكامل
2020
Xi, Jingen | Li, Hui | Xi, Jiamin | Tan, Shibei | Zheng, Jinlong | Tan, Zhongxin
Biochar plays an important role in soil improvement, pollutant removal, and nitrogen reduction. The excellent adsorption performance of biochar is closely related to its pore structure. Therefore, this paper combines a large amount of literatures to investigate the principle and method of preparing carbon materials by using the template method, and the idea of preparing high porosity biochar by template method was proposed. The results show that: (1) The specific surface area of the carbon materials prepared by the template method is more than 400 m² g⁻¹, and the total pore volume is more than 0.3 cm³ g⁻¹, which is much higher than the biochar materials prepared under the traditional high temperature anoxic pyrolysis. (2) Compared with the hard template method, a soft template method with simple operation, low toxicity of the compound, and low cost is selected. (3) The lignin, which is also a hydrophilic carbon source similar to phenolic resin, can be used as an ideal carbon precursor. (4) In the selection of templating agents, the specific surface area and total pore volume of carbon materials prepared by using F127 as a template are relatively large, showing more excellent pore size performance. (5) Finally, the idea of using template method to prepare high porosity biochar is proposed: lignin extracted from straw material is used as precursor, block polymer F127 is used as template, an appropriate amount of a cross-linking agent and a solvent is added, and finally the target biochar material is prepared by pyrolysis carbonization.
اظهر المزيد [+] اقل [-]Inflammatory effects of particulate matter air pollution النص الكامل
2020
Arias-Pérez, Rubén D. | Taborda, Natalia A. | Gómez, Diana M. | Narvaez, Jhon Fredy | Porras, Jazmín | Hernández, Juan C.
Air pollution is an important cause of non-communicable diseases globally with particulate matter (PM) as one of the main air pollutants. PM is composed of microscopic particles that contain a mixture of chemicals and biological elements that can be harmful to human health. The aerodynamic diameter of PM facilitates their deposition when inhaled. For instance, coarse PM having a diameter of < 10 μm is deposited mainly in the large conducting airways, but PM of < 2.5 μm can cross the alveolar-capillary barrier, traveling to other organs within the body. Epidemiological studies have shown the association between PM exposure and risk of disease, namely those of the respiratory system such as lung cancer, asthma, and chronic obstructive pulmonary disease (COPD). However, cardiovascular and neurological diseases have also been reported, including hypertension, atherosclerosis, acute myocardial infarction, stroke, loss of cognitive function, anxiety, and Parkinson’s and Alzheimer’s diseases. Inflammation is a common hallmark in the pathogenesis of many of these diseases associated with exposure to a variety of air pollutants, including PM. This review focuses on the main effects of PM on human health, with an emphasis on the role of inflammation.
اظهر المزيد [+] اقل [-]Comparative analysis on freshwater yield from conventional basin-type single slope solar still with cement-coated red bricks: an experimental approach النص الكامل
2020
Kabeel, Abd Elnaby | El-Agouz, El-Sayed | Athikesavan, Muthu Manokar | Duraisamy Ramalingam, Rajendran | Sathyamurthy, Ravishankar | Prakash, Nakka | Prasad, Chandran
This manuscript communicates the use of cement-coated red bricks for augmenting the production of distilled water using a traditional single slope solar still by low cost energy storage. The exposure area of water is increased in modified solar still (MSS) by keeping the cement-coated red bricks in the absorber. Using the energy storage material in the absorber, the water temperature was higher in the case of MSS at 20 kg water mass which was the minimum mass used during the experiment in the basin. From the results, it was also found that there is an improvement of about 34% in the temperature of water which acts as the driving force for evaporation of water inside the closed chamber. Furthermore, with increase in water temperature the productivity was enhanced by 45% as compared to the CSS. Comparison of different solar still on productivity was also analysed, and it is seen that the yield is higher in the present study by 38.8% than double slope-double basin solar still with different energy storage. The daily yield from CSS for water depth of 20, 30, 40 and 50 was found as 3.2, 2.8, 2.7 and 2.6 kg, whereas the modified solar still produced 6.3, 6, 5. 8 and 5.6 kg, respectively. Due to the reduced daily yield at higher water masses, the cost per litre of water produced from both conventional and modified solar still is higher.
اظهر المزيد [+] اقل [-]Si-Ca-K-Mg amendment reduces the phytoavailability and transfer of Cd from acidic soil to rice grain النص الكامل
2020
Wang, Yefeng | Ying, Yuqian | Lu, Shenggao
Cadmium (Cd) contamination in the soil-rice chain is the major threat to human health in China. It is very necessary to lower Cd phytoavailability in contaminated soils and reduce Cd transfer from soil to rice for food safety. This study applied the Si-Ca-K-Mg amendment (SCKM) to immobilize Cd in acidic soils and then reduce its accumulation in rice grain (Oryza sativa L.). Two agricultural soils (Alfisol and Ultisol) collected from Eastern China were treated with three levels of Cd concentration (0, 0.4, and 2.0 mg/kg), respectively, for pot experiment. The phytoavailability and chemical forms of Cd in two soils were determined using ethylenediaminetetraacetic acid (EDTA) and the European Community Bureau of Reference (BCR) extraction procedures. At 2.0 mg Cd/kg-treated soils, application of SCKM amendment increased the yield of rice grain by 10–17% for Alfisol and 14–39% for Ultisol, and reduced the concentrations of EDTA-extractable Cd by 6–27% for Alfisol and 5–25% for Ultisol, compared with treatment without amendment. SCKM amendment significantly (p < 0.05) reduced the bioconcentration factor (BCF) of Cd in root, straw, and grain of rice. Compared with treatment without amendment, the application of amendments decreased the Cd concentrations of rice grains by 35–76% for Alfisol and 31–72% for Ultisol, respectively. The BCR sequential extraction revealed that amendment reduced acid soluble Cd fraction by 6.2–13.6% for Alfisol and 6.1–13.5% for Ultisol, respectively, indicating that amendment could effectively transform the highly phytoavailable Cd into a more stable form. SCKM amendment addition significantly (p < 0.05) increased soil pH and exchangeable K⁺, and decreased exchangeable Al³⁺ contents in both soils. Our results demonstrated that SCKM amendment was effective in reducing the phytoavailability and transfer of Cd in soil-rice system, and ameliorating soil acidity. The SCKM amendment had greater potential as a low-cost and friendly environmentally amendment for safe production of rice in Cd-contaminated soils.
اظهر المزيد [+] اقل [-]Environmental cue affects the hearing-related behaviors of Drosophila melanogaster by targeting the redox pathways النص الكامل
2020
Dhar, Gyanaseni | Bag, Janmejaya | Mishra, Monalisa
Environmental cues like noise, pressure, and circadian rhythm can affect the hearing ability of human beings. Nevertheless, the complex physiology of the human being does not allow us to understand how these factors can affect hearing and hearing-related behaviors. Conversely, these effects can be easily checked using the hearing organ of Drosophila melanogaster, the Johnston organ. In the current study, the Drosophila was exposed to challenging environments like noise, low pressure, and altered circadian rhythm. The hearing organ of larvae, as well as adults, was analyzed for hearing-related defects. In the third instar larva, the cell deaths were detected in the antenna imaginal disc, the precursor of Johnston’s organ. Elevated levels of reactive oxygen species and antioxidant enzymes were also detected in the adult antennae of environmentally challenged flies. The ultrastructure of the antennae suggests the presence of abundant mitochondria in the scolopidia of control. Fewer amounts of mitochondria are found in the environmentally challenged adult antennae. In adults, various hearing-related behaviors were analyzed as a readout of functionality of the hearing organ. Analysis of climbing, aggressive, and courtship behaviors suggests abnormal behavior in environmentally challenged flies than the control. The current study suggests that the environmental cues can alter hearing-related behaviors in Drosophila. The methods used in this study can be used to monitor the environmental pollution or to study the effect of alteration of noise, pressure, and circadian rhythm on hearing-related behaviors taking Drosophila melanogaster as a model organism. Graphical abstract
اظهر المزيد [+] اقل [-]Developing the relationship between metal ionic characters and ecological risk assessment screening values using QICAR النص الكامل
2020
Li, Zhitao | Meng, Xiaoqi | Wang, Ying | Wang, Xuedong
Metals are widely released and distributed in soil and may have a negative impact on terrestrial organisms. Over the past years, a series of criteria or standards for assessing the ecological risks and toxicity of metals have been published in many countries; however, few studies have investigated their metal ionic properties and toxicity. In the present study, the ecological risk assessment screening values (ERASV) recommended by the Oregon Department of Environmental Quality were selected to investigate the correlation between metal toxicity and their ionic characters based on the hard and soft acids and bases (HSAB) concept. The results showed that more ionic characters were significantly correlated with ERASV using the HSAB theory, while only one metal ionic characteristic was correlated with ERASV in organisms. For borderline metal ions, maximum complex stability constants (log βn) and the softness (δp) of borderline ions were correlated with ERASV, while log βn and electronegativity (Xm) were significantly related to ERASV for borderline plus hard ions, and the boiling point (BP) and electron density (AR/AW) (AR indicates atomic radius and AW is atomic mass) were significantly related to ERASV for borderline plus soft ions. These results indicated that different metal ion characteristics play different roles in different types of metal toxicity in organisms and the mechanisms of toxicity are different. Based on these relationships, a set of quantitative ion characteristic parameter-activity relationship (QICAR) was developed. The QICAR predicted ERASV for metals that were reasonably consistent with those recommended by the Oregon Department of Environmental Quality, with differences between them generally < 2.0 orders of magnitude. However, there were discrepancies between the recommended and predicted values, and these discrepancies may be related to terrestrial geochemical properties. These soil properties should be further considered when developing QICAR models in future studies, such as soil type, organic matter, and pH. Overall, the QICAR models were able to determine the relationships between metal ionic properties and their toxicity and will be useful for assessing toxicity data on unknown toxic metals and will provide a basis for ecological assessment.
اظهر المزيد [+] اقل [-]First ecotoxicological characterization of paraffin microparticles: a biomarker approach in a marine suspension-feeder, Mytilus sp النص الكامل
2020
Nunes, Bruno | Simões, Maria Inês | Navarro, Juan Carlos | Castro, Bruno Branco
Microplastics are one of the main environmental pollutants in marine ecosystems, and their presence in seawater is a consequence of the widespread use of plastic materials in modern commodities. This wide usage of plastics includes the employment of microspheres in common personal care products, which end up being ultimately released into the aquatic compartment. Known ecotoxicological effects of microplastics favoured the search for technologically viable and environmentally safer alternatives, such as paraffin wax microparticles, whose ecotoxicological risks have not been entirely characterized. To address this gap, the present study exposed mussels (Mytilus sp.) for 96 h to three densities (5 mg/L, 20 mg/L and 80 mg/L) of four size ranges (100–300 μm, 300–500 μm, 400–850 μm, and 800–1200 μm) of paraffin wax particles. Toxicological endpoints were the activities of four enzymes involved in key cellular processes, including antioxidant defence (catalase (CAT), glutathione reductase (GRed) and glutathione peroxidase (GPx)) and phase II metabolism (glutathione S-transferases (GSTs)), as well as lipid content and fatty acid profiles of the digestive gland. Significant interactions between the presence/absence of food and paraffin particle density were found, as food sometimes worked as a confounding factor in the analysed biomarkers. Despite this uncertainty, some overall patterns emerged. In general, smaller paraffin wax particles (100–300 μm) caused little effects on the activity of the four enzymes tested, whereas larger particles (800–1200 μm) caused significant effects on almost all biomarkers. CAT activity was enhanced in animals exposed to larger paraffin particles, whilst GPx activity was depressed; GRed activity was not affected by the exposure to paraffin particles. The activity of GSTs was enhanced, but only in one tested condition. No effects were observed in terms of the total lipid content and fatty acids of exposed animals. Overall, data obtained in this work suggest that, at densities of paraffin wax particles comparable to the levels found in the environment for microplastic beads, no toxicity is expected to occur in the tested mussel species, by measuring the here-assessed toxicological endpoints.
اظهر المزيد [+] اقل [-]Adsorption and reduction of Cr(VI) by hydroxylated multiwalled carbon nanotubes: effects of humic acid and surfactants النص الكامل
2020
Huang, Yu | Song, Ke | Luo, Wei | Yang, Jiewen
The present study investigated the impacts of humic acid (HA) and surfactants (SDBS and CTAB), which were ubiquitously found in the aquatic environments, on the removal of Cr(VI) by the hydroxylated MWCNTs-OH. The results showed that MWCNTs-OH could remove Cr(VI) from aqueous solution via adsorption coupled with reduction, and the kinetics followed the pseudo-first-order model with the rate of 3.5 × 10⁻³ h⁻¹. In the presence of anionic SDBS, the removal percentage of Cr(VI) was greatly inhibited because the hydrophobic interaction and π-π interaction between SDBS and MWCNTs-OH surfaces not only decreased the adsorption sites for Cr(VI) but also made the surfaces more negatively charged. On the contrary, the existence of cationic CTAB could lead to the surfaces more positively charged, which consequently enhance the electrostatic attraction between Cr(VI) and the surfaces as well as the removal of Cr(VI). Noticeably, the presence of HA could promote the removal of Cr(VI), which was attributed to the reduction of Cr(VI) by the adsorbed HA. The ESR spectra indicated the existence of π-type radicals in HA structure and conduction electrons in MWCNTs-OH, and then the π-π interaction between MWCNTs-OH and adsorbed HA possibly increase the electron-donating ability of HA. Moreover, the promotive effect of HA could be enhanced with the addition of Ca²⁺. This study was helpful for us to understand the role of MWCNTs-OH in controlling the fate of Cr(VI) when HA and surfactants were present.
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