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Protective effect of Zingerone against mouse testicular damage induced by zinc oxide nanoparticles 全文
2019
Rafiee, Zeinab | Khorsandi, Layasadat | Nejad-Dehbashi, Fereshteh
The purpose of the present study was to evaluate the effect of Zingerone (Zing) on zinc oxide nanoparticle (ZNP)-induced spermatogenesis defects in mice. To this end, 50 mg/kg of ZNP was prescribed to the mice as an intoxicated group for 35 days. In protection groups, Zing (10, 20, and 40 mg/kg) was given prior to ZNP treatment for seven days and then co-administration of ZNP for 35 days. Epididymal sperm parameters, testicular histology, Johnsen’s scoring, morphometric parameters, TUNEL staining, oxidative stress, and serum testosterone level were evaluated for determining ZNP and Zing effects on the mouse testicles. Effects of Zing and ZNP on the viability of mouse Leydig (TM3) and mouse Sertoli (TM4) cell lines were also done. Testicular weights, testosterone levels, sperm quality, morphometric parameters, Johnsen’s score, and superoxide dismutase (SOD) and catalase (CAT) activities were significantly decreased in ZNP-intoxicated mice, while apoptotic index, Malondialdehyde (MDA) content, and histological features, including epithelial vacuolization, sloughing, and germ cell detachment, were improved significantly in ZNP-intoxicated mice. Pretreatment with 20 or 40 mg/kg Zing significantly reduced the histological criteria, increased morphometric parameters, enhanced testosterone levels, attenuated apoptotic index, improved sperm quality, and reversed oxidative stress by reducing the level of MDA and incrementing the activity level of SOD and CAT enzymes. Zing dose-dependently enhanced the viability of ZNP-treated TM3 and TM4 cells in comparison with only ZNP-exposed cells. According to the results of our study, Zing effectively prevented the defects in spermatogenesis among mice treated by ZNP.
显示更多 [+] 显示较少 [-]Evaluating the performance of SALTMED model under alternate irrigation using saline and fresh water strategies to winter wheat in the North China Plain 全文
2019
Soothar, Rajesh Kumar | Zhang, Wenying | Zhang, Yanqing | Tankari, Moussa | Mirjat, Uris | Wang, Yaosheng
The effective water management in the North China Plain (NCP) needs a tool to predict winter wheat production due to water quality. A large quantity of brackish water is stored underground in this region, and whether this water can be used properly in agriculture is becoming a crucial issue that is about to be resolved. The SALTMED model is a generic modeling tool for efficient irrigation management strategies, especially for cyclic use of saline and fresh water as well as different water qualities, and it still needs further investigation for alternate irrigation using saline and fresh water at different growth stages of winter wheat. Therefore, the aim of this investigation was to evaluate the performance of SALTMED model and simulate the production of winter wheat grown under different irrigation strategies. Irrigation strategies comprised rain-fed cultivation (NI), fresh and saline water irrigation (FS), saline and fresh water irrigation (SF), saline water irrigation (SS), and fresh water irrigation (FF). Three-year observed data were used for the validations of SALTMED model. The values of evaluation indices of relative error, RMSE, NRMSE, index of agreement (D-index), and R² between simulated and observed grain yield were 6.8%, 0.8, 10.7, 0.9, and 0.9, respectively. The model results supported and matched the observed data and indicated similar differences among the irrigated and rain-fed treatments. It is concluded that the SALTMED model is able to predict grain yield of winter wheat and its productivity under the alternate irrigation using saline and fresh water and their interaction in the climate condition of the NCP.
显示更多 [+] 显示较少 [-]Comparison of extraction techniques for polycyclic aromatic hydrocarbons from lichen biomonitors 全文
2019
Van der Wat, Leandri | Forbes, Patricia B. C.
Lichens are useful biomonitors for atmospheric polycyclic aromatic hydrocarbons (PAHs). Different sample preparation techniques were explored in this regard, including ultrasound-assisted solvent extraction, microwave-assisted extraction, Soxhlet, and the quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique. It was found that a QuEChERS technique using hexane:acetone (1:1, v/v), never reported before for application to lichens, provided the best recoveries of internal standards, the highest total peak area for all PAHs of interest, and %RSDs comparable with the other preparation techniques tested. The optimized sample preparation technique was found to be a comparatively fast method (45 min), with good recoveries (96%), using less solvents and minimal energy consumption. Strong matrix effects were found: both strong enhancement (for the lighter PAHs) and strong suppression (for the heavier PAHs). The use of matrix-matched standards is thus imperative for the accurate determination of PAH concentrations in the lichen samples. Graphical abstract “Note: This data is mandatory. Please provide.”
显示更多 [+] 显示较少 [-]Bibliometric analysis of global research on air pollution and human health: 1998–2017 全文
2019
Dhital, Sushma | Rupakheti, Dipesh
To give a basic overview of research publications on air pollution and human health, a bibliometric analysis of 2179 documents published during the last two decades (year 1998 to 2017) was carried out. The relevant data was retrieved from the Web of Science Core Collection (WoSCC) and analyzed by using the software such as VOSviewer 1.6.7, Tableau Public 2018.1, and Origin Pro 9.0 for visualization and mapping. The publication trend showed a drastic increase during the second decade. The most productive countries working in the field of air pollution and human health were the USA, China, Italy, England, and Canada, whereas top institutions were Chinese Academy of Sciences, US EPA, Harvard University, Peking University, and University of Sao Paulo. Likewise, leading authors in the context of number of documents published and co-citation were Michael Bell and C. Arden Pope respectively. Majority of the researches were published in the journals like Atmospheric Environment, Science of the Total Environment, and Environmental Science and Pollution Research whereas most common author keywords in the publications were “air pollution,” “particulate matter,” and “PM₂.₅.”
显示更多 [+] 显示较少 [-]Real-time monitoring and quantification of organic by-products and mechanism study of acetone decomposition in a dielectric barrier discharge reactor 全文
2019
Li, Xueshuang | Guo, Teng | Peng, Zhen | Xu, Li | Dong, Junguo | Cheng, Ping | Zhou, Zhen
Non-thermal plasma (NTP) degradation of low-concentration acetone was investigated in a cylindrical dielectric barrier discharge reactor. The effects of oxygen content and flow rate on the removal efficiency at various discharge powers were examined in real-time. The acetone removal efficiency decreases drastically and then remains stable or increases gradually as the O₂ content increases from 0 to 25%, and further to 50%. The organic by-products were characterized and quantified using a real-time proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) instrument. The observed organic compounds, with concentrations about ppbv/ppmv by volume, were mainly formaldehyde, methanol, ketene, acetaldehyde, formic acid, acetone, and acetic acid. The discharge power was a critical factor affecting the concentration of the organic by-products and the selectivity toward CO₂. The mechanism study based on the by-product monitor in real-time showed that acetone firstly fragments into methyl radicals, acetyl radicals, and H; then, the methyl and acetyl radicals are oxidized by O or OH radicals into acetaldehyde, methanol, and other compounds. It seems that acetaldehyde could be an intermediate in acetone decomposition. Firstly, most of the acetone molecules were decomposed into acetaldehyde molecules; then, the acetaldehyde molecules continued to be decomposed and oxidized into other compounds, such as acetic acid and formaldehyde. These investigations not only proposed a detail decomposition mechanism for acetone in dielectric barrier discharge reactor, but also provided a potential way to analyze and evaluate the practicability of NTP removal of VOCs.
显示更多 [+] 显示较少 [-]Assessment of strength and leaching characteristics of heavy metal–contaminated soils solidified/stabilized by cement/fly ash 全文
2019
Zha, Fusheng | Ji, Chunjie | Xu, Long | Kang, Bo | Yang, Chengbin | Chu, Chengfu
Solidification/stabilization technique has been widely adopted to remediate the heavy metal–contaminated sites. In the present work, the strength and leaching characteristics of the contaminated soils solidified/stabilized by cement/fly ash were systemically investigated. Electrical resistivity was also measured to establish empirical relationships for assessment of remediation efficacy. Tests results showed that the unconfined compressive strength increased and the leached ion concentration decreased with increasing curing time. In contrast, the unconfined compressive strength decreased and the leached ion concentration increased with increasing initial heavy metal ion concentration in the specimen. For the strength characteristic, the most notable detrimental effect was induced by Cr³⁺ and the least was induced by Pb²⁺. For the leaching characteristic, the trend was reversed. The electrical resistivity of the tested specimen increased significantly with increasing curing time and with decreasing initial ion concentration. The electrical resistivity of the Pb-contaminated specimen was higher than that of the Zn-contaminated specimen, which in turn was higher than that of the Cr-contaminated specimen. Empirical relationships between the strength, leaching characteristic, and electrical resistivity were established, which could be adopted to assess the remediation efficacy of heavy metal–contaminated soil solidified/stabilized by cement/fly ash.
显示更多 [+] 显示较少 [-]A Bayesian assessment of occupational health surveillance in workers exposed to silica in the energy and construction industry 全文
2019
Abad, Alberto | Gerassis, Saki | Saavedra, Ángeles | Giráldez, Eduardo | García, Julio F. | Taboada, Javier
Medical records generated during occupational health surveillance processes have large amounts of unexploited information that can help to reduce silica-related health risks and many occupational diseases. The methodology applied in this study consists in analyzing through machine learning techniques a database with 70,000 medical examinations from workers in the energy and construction industry in Spain. First, a general unsupervised Bayesian model is built and node force analysis is used to identify the factors with the greatest impact on the worker’s health surveillance process. Second, a predictive Bayesian model is created and mutual information is employed to assess the more relevant factors affecting the medical capability of workers exposed to silica dust. The lung auscultation and the breathing exploration are the two factors that influence the most the medical capability of silica-exposed employees. Probabilistic inference shows a remarkable gender effect, where women present more resilience towards occupational diseases than men showing a higher proportion of normal results in certain key factors, such as body mass index (♀49.73%, ♂25.17%) or spirometry (♀53.73%, ♂48.91%). Finally, environmental conditions demonstrate to have a major influence on spatial variability of occupational diseases. The design of health prevention programs based on geographical variations can be crucial to the attainment of an ongoing and sustained healthier workforce with a reduction in the number of chronic workplace illnesses.
显示更多 [+] 显示较少 [-]Self-assembly of sponge-like kaolin/chitosan/reduced graphene oxide composite hydrogels for adsorption of Cr(VI) and AYR 全文
2019
Zhang, Yakun | Chen, Sisi | Feng, Xuezhen | Yu, Jingang | Jiang, Xinyu
The assembly of graphene oxide with biomass or polymers to form 3D hydrogels with excellent mechanical properties has become a research hotspot. In this work, the sponge-like kaolin/chitosan (CS)/reduced graphene oxide (rGO) composite was prepared for adsorption by simple self-assembly without cross-linking agent. The morphology, composition, surface properties, and pore size of as-prepared materials were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), zeta potential analyzer, Brunauer-Emmett-Teller surface area measurement (BET), and scanning electron microscopy (SEM). The effects of raw material ratio, contact time, temperature, pH, ionic strength, and recycling times on adsorption performance were investigated in detail. The results indicate that the composite has good absorption capacity for Cr(VI) and alizarin yellow R (AYR). Besides, composite hydrogel also exhibits excellent flexibility and good repeatability, which confirms its great potential as an adsorbent to remove pollutants in the water environment.
显示更多 [+] 显示较少 [-]Effects of operating parameters on in situ NH3 emission control during kitchen waste composting and correlation analysis of the related microbial communities 全文
2019
Ding, Ying | Wei, Jiaojiao | Xiong, Junsheng | Zhou, Bowei | Cai, Hanjiang | Zhu, Weiqin | Zhang, Hangjun
Ammonia emission during composting results in anthropogenic odor nuisance and reduces the agronomic value of the compost due to the loss of nitrogen. Adjusting the operating parameters during composting is an emerging in situ odor control technique that is cheap and highly efficient. The effects of in situ NH₃ emission control were investigated in this study by simultaneously adjusting key operating parameters (such as C/N ratio, aeration rate, and moisture content) during the composting processes (C1–C9). Results showed that the average NH₃ emission concentrations for different treatments were in the order of C1 > C4 > C2 > C5 > C3 > C6 > C7 > C8 > C9. The total content of NH₃ emission (21.02 g/kg) in C9 (C/N ratio = 35, aeration rate = 15 L/min, and moisture content = 60%) was much lower than that (65.95 g/kg) in C1 (C/N ratio = 15, aeration rate = 5 L/min, and moisture content = 60%). The nitrogen loss ratio was 27.36% for C1, while 16.15% for C9. The microbial diversity and abundance in C9 and C1 were compared using high-throughput sequencing. The relationship between NH₃ emission, operating parameters, and the related functional microbial communities was also investigated. Results revealed that Nitrosospira, Nitrosomonas, Nitrobacter, Pseudomonas, Methanosaeta, Rhodobacter, Paracoccus, and Sphingobacterium were negatively related to NH₃ emission. According to the above results, the optimal values for different operating parameters for the in situ NH₃ control during kitchen waste composting were, respectively, moisture content of 70%, C/N ratio of 35, and aeration rate of 15 L/min, with the order of effectiveness from high to low being aeration rate > C/N > moisture. This information could be used as a valuable reference for the in situ NH₃ emission control during kitchen waste composting.
显示更多 [+] 显示较少 [-]The enhanced lipid productivity of Chlorella minutissima and Chlorella pyrenoidosa by carbon coupling nitrogen manipulation for biodiesel production 全文
2019
Bharte, Supriya | Desai, Kruttika
Biodiesel production from microalgae has been researched extensively and attempted to commercialize on a large scale, but there are major hurdles in the production process like harvesting and low lipid content, which should be studied to enhance the process and make it economical. Present study aimed to improve the lipid productivity of Chlorella minutissima and Chlorella pyrenoidosa by modifying the carbon and nitrogen content of the medium. Both organisms were grown in BG11 medium for the first 6 days and thereafter grown in a modified BG11 medium completely deprived of nitrogen for 2 to 10 days. Nitrogen deprivation increased the lipid productivity of Chlorella minutissima to 20% and that of Chlorella pyrenoidosa to 17.6% by day 6. This was further coupled with carbon addition in the form of citric acid (5 g/L), sodium acetate (5 g/L), sodium carbonate (5 g/L), and sodium potassium tartarate (5 g/L), which increased the total lipid productivity of Chlorella minutissima up to 24% and that of Chlorella pyrenoidosa up to 23%. The highest lipid productivity of up to 24% for Chlorella minutissima and up to 23% for Chlorella pyrenoidosa was observed with nitrogen deprivation coupled with sodium acetate. Acidic transesterification revealed the presence of fatty acid methyl esters, majority of which consisted of hexadecanoic acid methyl ester and octadecanoic acid methyl ester. Maximum of 3% fatty acid methyl esters for Chlorella minutissima and 4% for Chlorella pyrenoidosa were obtained under nitrogen deprivation and sodium acetate as a carbon source. Thus, nitrogen deprivation coupled with sodium acetate as an increased carbon source in BG11 medium helps to increase the lipid productivity of Chlorella minutissima and Chlorella pyrenoidosa, and produces long-chain fatty acid methyl esters of C17 and C19 along with C21, C25, and C29.
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