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Stroke is an acute cerebrovascular disease resulting from either obstruction or rupture of a blood vessel in the brain. Oxidative stress (OS), referred to a status where cellular oxidative capacities overwhelm antioxidative defenses, is involved in the pathophysiology of stroke. The bibliometric analysis and in-depth review aim to depict the research trend of OS in stroke. Relevant scientific publications were acquired from the Web of Science Core Collection database. Scientific landscape of OS in stroke was illustrated by general quantitative trend, impactful journals, and co-authorship of various academic units (i.e., countries/regions, organizations, and authors). Furthermore, theme analysis predicting the hot research issues and frontiers was performed. 15,826 documents regarding OS in stroke were obtained over a time span of more than 20 years from 1992 to 2021. The overall tendency of publication counts was continuously on the rise. Bibliometric analysis indicated China and the United States were predominant in this study field, as reflected by their high publication counts and intensive collaboration with other countries. Current key research areas of OS in stroke may lie in the investigation of neuroinflammation, and interaction among multiple cell death mechanisms including apoptosis, autophagy, and ferroptosis to search for effective treatments. Moreover, another hot topic could be the association between air pollution and stroke, and its underlying mechanisms. As the exploration of OS in stroke is speculated to be a continuous hot spot in the future, this article may be helpful for researchers to conduct future studies with the understanding of influential academic forces and research highlights. [ABSTRACT FROM AUTHOR]

The halogenated polycyclic aromatic hydrocarbons (H-PAHs) have been paid increasing attentions due to their potential health hazards. This research firstly investigated distribution and cancer risk of 7 parent polycyclic aromatic hydrocarbons (PAHs) and 19 H-PAHs in Songhua river and Songhua lake of Jilin city, China. The results indicate that 7 parent PAHs and 12 H-PAHs were coexisted. The total concentrations of PAHs, Cl-PAHs, and Br-PAHs respectively ranged from 75.6 to 323.33 with a median concentration of 164.48 ng/L, n.d. to 45.87 with a median concentration of 2.19 ng/L, and n.d. to 56.93 ng/L with a median concentration of 4.67 ng/L. The seasonal variation was obvious; the highest total concentrations of PAHs and H-PAHs were occurred in melt season, which suggests that melting snow and riverine input were major sources of PAHs and H-PAHs. For cancer risk, the incremental lifetime cancer risk (ILCR) values of PAHs and HPAHs for all the sampling sites and water seasons were lower than 1.00E-06, suggesting that the cancer risk of these compounds were low, while the cancer risk may be underestimated due to a lack of toxicity data for some H-PAHs. [ABSTRACT FROM AUTHOR]

In order to realize the simultaneous removal of nine metal ions from water, in this study, an excellent flocculant suitable for the simultaneous removal of multiple metal ions in water was developed by using the excellent flocculation properties of graphene oxide (GO) combined with biological flocculants. First, this study investigated the concentrations and pollution levels of nine metal pollutants in surface water and groundwater of a typical city in central China. The maximum concentrations of these nine metal ions were Al 0.29, Ni 0.0325, Ba 0.948, Fe 1.12, As 0.05, Cd 0.01, Zn 1.45, Mn 1.24, and Hg 0.16 (in mg/L). Second, the three-dimensional structure diagram of GO was established. Gaussian16W software and the pm6D3 semi-empirical method were used to analysis the structure and the vibration of GO. The B3LYP function and basis set DEF2SVP was used to calculate the single point energy. Third, with varying the flocculation time, it was found that the maximum flocculation efficiency could reach more than 80.00% under the optimal conditions, that is, with a metal ion mixture of 20 mg/L. The optimal dosage of GO was 15 mg/L. The optimal time for bioflocculation efficiency was 2.5 h, and the optimal concentration of bioflocculant was 3 mg/L. The optimal flocculation efficiency was 82.01% under the optimal conditions. [ABSTRACT FROM AUTHOR]

Daily use of plastic feeding and water bottles occur widely in China, and they could be sources for release of microplastics (MPs), which threaten the health of Chinese infants and children during daily usage. In this work, we investigated the use of polycarbonate (PC) and polypropylene (PP) for making water bottles (WBs) and polyphenylene sulfone resins (PPSU) for making feeding bottles (FBs), and we found that feeding bottles and water bottles released microparticles in amounts ranging from 53 to 393 particles/mL during 100 opening/closing cycles. The good linear regressions for plots of microparticles released vs. abrasion distance (r2 = 0.811) indicated that thick-necked bottles release more microparticles than thin-necked bottles. The brands and types of bottles (plastic vs. glass) influence microparticle release, and this indicates that high-quality plastic and glass bottles release fewer microparticles and are good for the health of infants and children. In addition to calcium stearate and silicone additives, the identified MPs account for 7.5 to 42.1% of released microparticles with different polymer types, sizes (from 20 to 500 μm) and shapes (cubic, spherical and irregular shapes). Additionally, an average of 1.74 MPs were released from an injection with a single-use plastic injector. Nevertheless, a number of microparticles and nanosized plastics were observed with all samples, suggesting that the health risks of micro- and nanosized particles to humans, especially babies and children, and the environment should be considered seriously. [ABSTRACT FROM AUTHOR]

The fate and risk assessment of silver nanoparticles (Ag NPs) is an important environmental health issue. The toxic effects, mechanisms, and modes of action of Ag NPs on aquatic organisms have been extensively determined in the laboratory. However, knowledge gaps and discrepancies exist between laboratory studies and realistic environmental research; such inconsistencies hinder the development of health and safety regulations. To bridge these gaps, this review summarizes how environmental conditions and the physicochemical properties of Ag NPs affect the inconsistent findings between laboratory studies and realistic environmental research. Moreover, this paper systematically reviews different toxic effects of Ag NPs in a realistic environment and compares these effects with those in the laboratory, which is helpful for assessing the environmental fate and risk of Ag NPs. The hazardous effects of Ag NPs on the whole aquatic ecosystem with low concentrations (μg L−1) and long-term periods (months to years) are detailed. Furthermore, two perspectives of future toxicity studies of Ag NPs in realistic freshwater environments are emphasized. [ABSTRACT FROM AUTHOR]

The distribution and fate of organic pollutants determines pollution control strategies and definition of environmental standards. So far, few models predict accurately the fate of organic pollutants. Therefore, here we tested the Markov chains model to simulate the distribution and fate of nonylphenol and naphthalene in the aquatic environment. Results show that the removal of nonylphenol and naphthalene from the water/sediment system is higher in the wet season and lower in the dry season. Due to its hydrophilic hydroxyl group, nonylphenol remains in water, whereas naphthalene, being more hydrophobic, accumulates in the sediment. Results of Markov chains modeling perfectly matched results from microcosm experiments. [ABSTRACT FROM AUTHOR]

In this paper, spatiotemporal variability of drought in Xilingol grassland during pasture growing season (from April to September) was investigated, using 52 years (1961-2012) of precipitation data recorded at 14 rain gauge stations in the study area. The Standardized Precipitation Index was used to compute the severity of drought. The Mann-Kendall test, the linear trend, and the sequential Mann-Kendall test were applied to standardized precipitation index (SPI) time series. The results indicate that drought has become increasingly serious on the region scale during pasture growing season, and the rate of SPI decreases ranged from −0.112 to −0.013 per decade. As for the MK test, most of the stations, the Z value range is from −1.081 to −0.005 and Kendall’s τ varies from −0.104 to −0.024. Meanwhile, drought is increased obviously from the northwest to the southeast region. Meanwhile, the occurrence probability of each severity class, times for reaching different drought class from any drought severity state, and residence times in each drought class have been obtained with Markov chain. Furthermore, the drought severities during pasture growing season in 2013-2016 are predicted depending on the weighted Markov chain. The results may provide a scientific basis for preventing and mitigating drought disaster. [ABSTRACT FROM AUTHOR]

The information on concentration levels, partitioning and sources of pollutants in aquatic environment is quite necessary for pollution treatment and quality criteria. In this work, sixteen priority polycyclic aromatic hydrocarbons (PAHs) recommended by U.S. Environmental Protection Agency in the water and sediment of Yinma River Basin were firstly investigated. Among 16 individual PAHs, naphthalene was the highest average concentration in water samples as well as in sediment samples, 67.2 ng/L and 825.06 ng/g, respectively, whereas benzo(g,h,i)perylene was undetected in water samples nor in sediment samples. For three PAH compositional patterns, concentrations of light (2-3 ring) PAHs were dominant in water and sediment, accounting for 71.69 and 86.98 % respectively. The PAH partitioning in the sediment-water system was studied, results showed that PAH partitioning was in an unsteady state and tended to accumulate in the sediment. The possible sources of PAHs in water and sediment were both identified as a mixed source of petroleum and combustion. The benzo(a)pyrene equivalents (EBaP) values for PAHs in the water and sediment in some sites were relatively higher, suggesting the existence of environmental health risk. [ABSTRACT FROM AUTHOR]

Phenanthrene (Phe) with carcinogenicity is ubiquitous in the environment, especially in aquatic environment; its toxicity is greater. To help determine toxicity risk and remediation strategies, this study predicted seasonal fate of Phe in aquatic environment. Candidate mechanisms including biodegradation, sorption, desorption, photodegradation, hydrolysis and volatility were studied; the results for experiments under simulated conditions for normal, wet and dry seasons in the Yinma River Basin indicated that biodegradation in sediment, sorption, desorption, and volatility were important pathways for elimination of Phe from aquatic environment and showed seasonal variations. A microcosm which was used to mimic sediment/water system was set up to illustrate seasonal distribution and transport of Phe. A Markov chain was applied to predict seasonal fate of Phe in air/water/sediment environment, the predicted results were perfectly agreed with results of microcosm experiments. Predicted results with a Markov chain suggested that volatility and biodegradation in sediment were main elimination pathways, and contributions of elimination pathways showed seasonal variations; Phe was eliminated from water and sediment to negligible levels over around 250 h in August and over 1000 h in May; in November, Phe was eliminated from water to a negligible level while about 31 % of Phe amount still remained in sediment over 1000 h. [ABSTRACT FROM AUTHOR]

The authors investigate the global existence and semiclassical limit of weak solutions to a sixth-order parabolic system, which is a quantum-corrected macroscopic model derived recently to simulate the quantum effects in miniaturized semiconductor devices. [ABSTRACT FROM AUTHOR]

Bioflocculation, being environmental-friendly and highly efficient, is considered to be a promising method to harvest microalgae. However, one limitation of this technology is high expense on substrates for bioflocculant bacteria cultivation. In this regard, we developed an innovative method for the inner-recycling of biomass that could harvest the typical microalgae, Microcystis aeruginosa, using a bioflocculant produced by Citrobacter sp. AzoR-1. In turn, the flocculated algal biomass could be reutilized as a substrate for Citrobacter sp. AzoR-1 cultivation and bioflocculant production. The experimental results showed that 3.4 ± 0.1 g of bioflocculant (hereafter called MBF-12) was produced by 10 g/L of wet biomass of M. aeruginosa (high-pressure steam sterilized) with an additional 10 g/L of glucose as an extra carbon source. The efficiency of MBF-12 for M. aeruginosa harvesting could reach ~95% under the optimized condition. Further analysis showed that MBF-12, dominated by ~270 kDa biopolymers, contributed the bioflocculation mechanisms of interparticle bridging and biosorption process. Bioflocculant synthesis by Citrobacter sp. AzoR-1 using microalga as a substrate, including the polyketide sugar unit, lipopolysaccharide, peptidoglycan and terpenoid backbone pathways. Our research provides the first evidence that harvested algae can be reutilized as a substrate to grow a bioflocculant using Citrobacter sp. AzoR-1. [ABSTRACT FROM AUTHOR]