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Evaluation of trace elements in the water of Lancang River during the wet season (October) and dry season (December) was carried out to analyze the content of trace elements in the water, spatial and seasonal variations, enrichment, and health risks of dissolved trace metal. The results showed that the content of trace elements in the main stream of the upper Lancang River met the “Environmental Quality Standard for Surface Water” (GB3838-2002) Class I water-quality standard, but the Fe content in sampling points during the wet season exceeded the limit value of water-quality standard. Compared with other rivers in Tibet, the contents of As, Fe, and Pb in the study were relatively high. While Pb, As, and Zn were the mainly enriched trace elements. The water temperature, dissolved oxygen, conductivity, As, Cr, and Cu in the main stream of the upper Lancang River with significant seasonal variations. The content of trace elements in the front of the dam was lower than that in the tail and under the dam. The trace elements in the water of the reservoir area increased with an increase in the depth, and the reservoir had a certain interception effect on the trace elements. The As content in the main stream of the Lancang River was greatly affected by the branch of Angqu with high content of As. The HQingestion and HI of As in the part of the river in the study exceeded 1, and the water-quality health risks of the Guoduo reservoir tail and urban reaches were higher than those of other reaches, which should be paid more attention.

Background It has been indicated that protein kinase C (PKC) plays a vital role in the pathogenesis of hypoxia-induced pulmonary hypertension (PH). The functions or the pathogenic roles of PKCs vary from different types, and their related downstream pathways may also be distinct. Therefore, the specific role of different types of PKC deserves to be elucidated. Discussions regarding conventional PKC (cPKC) have dominated research in recent years, however, the relationship between novel PKC (nPKC) and the development of PH remain unclear. In addition, it is less known whether nPKC has a direct effect on the proliferation of pulmonary artery smooth muscle cells (PASMCs). This study is designed to investigate the role of nPKC in mediating PASMCs proliferation in PH and the underlying mechanisms. Methods Mouse PASMCs was isolated using magnetic separation technology. The PASMCs were divided into 24 h group, 48 h group and 72 h group according to different hypoxia treatment time, then detected cell proliferation rate and nPKC expression level in each group. We treated PASMCs with agonists or inhibitors of PKCδ and PKCε and exposed them to hypoxia or normoxia for 72 h, then measured the proliferation of PASMCs. We also constructed a lentiviral vector containing siRNA fragments for inhibiting PKCδ and PKCε to transfected PASMCs, then examined their proliferation. Results PASMCs isolated successfully by magnetic separation method and were in good condition. Hypoxia promoted the proliferation of PASMCs, and the treatment for 72 h had the most significant effect. Hypoxia upregulated the expression of PKCδ and PKCε in mouse PASMCs, leading to PASMCs proliferation. Moreover, Our study demonstrated that hypoxia induced upregulation of PKCδ and PKCε expression resulting to the proliferation of PASMCs via up-regulating the phosphorylation of AKT and ERK. Conclusions Our study provides clear evidence that increased nPKC expression contributes to PASMCs proliferation and uncovers the correlation between AKT and ERK pathways and nPKC-mediated proliferation of PASMCs. These findings may provide novel targets for molecular therapy of pulmonary hypertension.

By surveying and evaluating the δD and δ18O values of the water in the source region of the Yangtze River and the Lancang River, the characteristics of the hydrogen and oxygen stable isotope composition have been analyzed. The results showed that the ranges of δD and δ18O values varied from −126.28‰ to −47.96‰ and −16.77‰ to −7.13‰. The standard deviation of δD and δ18O value are 18.58‰ and 2.34‰. The stability of δ18O value is better than δD. Atmospheric precipitation is the principal source of river water supply in the region. The Local Meteoric Water Line equation is δD = 7.73 δ18O + 4.81 (R2 = 0.96, n = 19). Due to strong evapotranspiration, its slope and intercept are smaller than the Global Meteoric Water Line. The strong evapotranspiration in the source regions causes most of the d-excess to be negative, and the ice-snow melt water replenishment feature causes some d-excess to be positive. δD and δ18O values in the source regions exhibited certain latitude effect and continental effect.

Excessive phosphorus (P) loading was identified as an urgent problem during the post-Three Gorges Reservoir (TGR) period. Turbid water with high suspended sediment loads has been periodically released during the flood season to mitigate sediment deposition in the TGR, but limited attention has been paid to its effect on the distribution of P in bed sediment within the reservoir. In this study, field surveys, historical monitoring data related to sediment deposition, and physiochemical properties and the fractional P content in the mainstream surface sediment and representative column sediment, were used to investigate the effect of turbid flood water release on P distribution in bed sediment. The results revealed that turbid flood water release could discharge approximately 20% of the suspended sediment inflow entering the TGR. Additionally, both the particle size of the inflow sediment and suspended sediment flux tended to decline, and the deposited sediment volume tended to constantly increase in the TGR at a rate of 0.117 billion tonnes per year between 2004 and 2016. The median particle size (MPS) was larger for surface sediment obtained in the flood season than for that obtained in the dry season, and the MPS tended to increase with an increase in the sediment depth from 0 to 20 cm. The total phosphorus (TP) content in sediment ranged from 2.6% to 17.5% lower in the flood water releasing period than in the non-flood water storing period. However, no consistent variation was detected for the vertical distribution of P fraction in the top 20 cm of bed sediment. Compared with lakes with slow deposition rates, the TGR showed a rapid sedimentation rate of >1.0 m/y, which mostly resulted in the uniform distribution of the surface sediment P fraction.

To develop a method to measure simultaneously the concentration of BTEX (benzene, toluene, ethylbenzene, m/p-xylene, o-xylene) in human whole blood with Purge and Trap-Gas Chromatography-Mass Spectrometry. The conditions of purge and trap were optimized, so that the BTEX in human whole blood could be enriched and desorbed, and then characteristic ions could be selected with gas chromatography–mass spectrometry combined with isotope internal standard for qualitative and quantitative analysis. After the parameters of purge and trap method were optimized, the BTEX in human whole blood could be simultaneously enriched, desorbed and measured accurately. The detection limit with this method ranges from 0.001 μg/L to 0.004 μg/L. The Linear range is from 0.021 μg/L to 10.99 μg/L. The recovery rate of low concentration (0.687 μg/L) solution is in the range of 79.21% to 85.92%; the recovery rate of high concentration (2.747 μg/L) solution is in the range of 93.21% to 102.07%. The analysis of the same sample is repeated for six times with its relative standard deviation ranging from 2.77% to 5.40%. With simple operation, short analysis period, good separation as well as required accuracy and precision, this method could analysis of BTEX concentration in human whole blood.

Phytoremediation is an economic and promising technique for removing toxic pollutants from the environment. Freshwater sediments are regarded as the ultimate sink of the widely used PBDE congener decabromodiphenyl ether (BDE-209) in the environment. In the study, the aquatic macrophyte Scirpus validus was selected to remove BDE-209 from three types of sediments (silt, clay, and sand) at an environmentally relevant concentration. After 18 months of phytoremediation experiment, S. validus significantly enhanced the dissipation rates of BDE-209 in all the sediments compared to the controls. Average removal rates of BDE-209 in the three treatments of silt, clay, and sandy sediments with S. validus were respectively 92.84, 84.04, and 72.22%, which were 148, 197, and 233% higher than that in the control sediments without S. validus. In the phytoremediation process, the macrophyte-rhizosphere microbe combined degradation was the main pathway of BDE-209 removal. Sixteen lower brominated PBDE congeners (di- to nona-) were detected in the sediments and plant tissues, confirming metabolic debromination of BDE-209 in S. validus. A relatively higher proportion of penta- and di-BDE congeners among the metabolites in plant tissues than that in the sediments indicated further debromination of PBDEs within plants. The populations and activities of microorganisms in the sediments were greatly promoted by S. validus. Bacterial community structure in BDE-209-contaminated rhizosphere sediments was different from that in the control rhizosphere sediment, as indicated by the dominant proportions of β-proteobacteria, δ-proteobacteria, α-proteobacteria, Acidobacteria, and Chloroflexi in the microbial flora. All these results suggested that S. validus was effective in phytoremediation of BDE-209 by the macrophyte-rhizosphere microbe combined degradation in aquatic sediments.

With the rapid development of the steel industry, the accumulation of steel slag increases year by year, occupying a large amount of farm land and leading the problem of environmental pollution and safety hazards. The current comprehensive utilization rate of steel slag is still very low in China, far behind the developed countries. The low comprehensive utilization rate of steel slag is a stumbling block to the green and sustainable development of the Yangtze River Economic Belt. Improving the comprehensive utilization rate of steel slag is an imperative way to resolve these problems and to realize sustainable development for the steel enterprise. Steel slag presents porous structure and large surface area; in addition, it is easy to separate from water due to its high density. Therefore, the application of steel slag in industrial waste water treatment has received intensive attention in recent years. This paper systematically introduced the research progress of steel slag resource utilization as absorbent materials for waste water and proposed the important improved method and critical problems for steel slag as absorbent materials.

Water, sediment, and zoobenthos are crucial carriers and storage media for heavy metal migration and transformation. The distribution characteristics of heavy metals in water, sediment, and zoobenthos can reflect their pollution status and potential influences on the health of aquatic ecosystems. On the basis of monitoring data related to Cu, Zn, Pb, Cd, Ni, Mn, Hg, and As in mainstream water, surface sediment, and zoobenthos at eight sections-from Wuhan to Shanghai-of the Changjiang River (also known as the Yangtze River) and historical monitoring data on heavy metal distributions in different environmental media of the Changjiang River since the 1980s, this study undertook systematically analyzed the spatiotemporal distribution dynamics, pollution levels, and corresponding environmental risks related to heavy metals in water, sediment, and biota, and examined the effects of pollution source variations and water and sediment regimes on heavy metal distribution. Heavy metal concentrations in the waters were much lower than the water quality threshold of Grade III of the Chinese Surface Water Environmental Quality Standard (GB3838-2002); the concentrations of different heavy metals were irregularly distributed and varied significantly along the river mainstream; Cu, Cd, Zn, and Pb concentrations in sediment all exceeded their respective critical effect concentrations and exposed the ecosystem to pollution risks; the pollution levels of and ecosystem health risks posed by Zn and Cu in zoobenthos were high, with pollution concentrations ranked as shrimp > snails > crabs. In general, heavy metal concentrations in the three environmental mediums were ranked as sediment > zoobenthos > water. Finally, comparison with historical monitoring data revealed increasing Cd and Hg concentrations, with the average heavy metal concentration in sediment reaching its maximum value in the 2000s in the middle and lower reaches of the Changjiang River, which are subjected to the combined effect of pollutant emissions and changing water and sediment regimes.

Heavy metal contamination in surface water of the Three Gorges Reservoir (TGR) is a distinctly important issue for the water security of the Yangtze River Basin in China. Surface water samples of 46 river sections in the main stream and tributaries of the entire TGR area were collected during high and low water level operation periods of 2015 to 2016 to investigate the spatial-temporal distribution characteristics of six heavy metals (As, Cd, Cr, Cu, Pb and Zn) and assess their health risks. Results indicated that average concentrations of heavy metals in the surface water were lower than the threshold values for the first-grade water quality based on the Chinese standard of GB3838-2002 except for Zn. Heavy metals concentrations at high water levels was slightly lower compared with that at the low water levels in the main stream, As, Cd, Cr and Cu exhibited certain inter-annual decline variations in 2015 and 2016. Heavy metals showed distinctly regional variation and mainly distributed in upstream urban sections of the TGR area. The total health risks caused by heavy metals at the low water level periods, most of which exceeded the maximum acceptable risk level recommended by ICRP (5×10−5 a−1), were slightly higher than that at the high water level periods. The average annual health risks caused by carcinogenic and non-carcinogenic heavy metals was ranked as Cr > As > Cd > Pb > Cu > Zn, meanwhile this value via drinking water ingestion was 2 to 3 orders of magnitude larger than that of dermal contact. Carcinogenic heavy metals of Cr and As were the main causes of health risk and should be prioritized as the main focus of aquatic environment risk management in the TGR area.

This study is designed to investigate the role of novel protein kinases C (nPKC) in mediating pulmonary artery smooth muscle cells (PASMCs) proliferation in pulmonary hypertension (PH) and the underlying mechanisms. Mouse PASMCs was isolated using magnetic separation technology. The PASMCs were divided into 24 h group, 48 h group and 72 h group according to different hypoxia treatment time, then detected cell proliferation rate and nPKC expression level in each group. We treated PASMCs with agonists or inhibitors of PKCdelta (PKCδ) and PKCepsilon (PKCe) and exposed them to hypoxia or normoxia for 72 h, then measured the proliferation of PASMCs. We also constructed a lentiviral vector containing siRNA fragments for inhibiting PKCδ and PKCe to transfected PASMCs, then examined their proliferation. PASMCs isolated successfully by magnetic separation method and were in good condition. Hypoxia promoted the proliferation of PASMCs, and the treatment for 72 h had the most significant effect. Hypoxia upregulated the expression of PKCδ and PKCe in mouse PASMCs, leading to PASMCs proliferation. Moreover, Our study demonstrated that hypoxia induced upregulation of PKCδ and PKCe expression resulting to the proliferation of PASMCs via up-regulating the phosphorylation of AKT and ERK. Our study provides clear evidence that increased nPKC expression contributes to PASMCs proliferation and uncovers the correlation between AKT and ERK pathways and nPKC-mediated proliferation of PASMCs. These findings may provide novel targets for molecular therapy of pulmonary hypertension.

Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence characteristics of Microcystis aeruginosa were investigated in order to reveal the mechanisms of electrolytic inhibition of algae. Threshold of current density was found under a certain initial no. of algae cell. When current density was equal to or higher than the threshold (fixed electrolysis time), growth of algae was inhibited completely and the algae lost the ability to survive. Effect of algal solution volume on algal inhibition was insignificant. Thresholds of current density were 8, 10, 14, 20, and 22 mA cm(-2) at 2.5 × 10(7), 5 × 10(7), 1 × 10(8), 2.5 × 10(8), and 5 × 10(8) cells mL(-1) initial no. of algae cell, respectively. Correlativity between threshold of current and initial no. of algae cells was established for scale-up and determining operating conditions. Changes of chlorophyll fluorescence parameters demonstrated that photosystem (PS) II of algae was damaged by electrolysis but still maintained relatively high activity when algal solution was treated by current densities lower than the threshold. The activity of algae recovered completely after 6 days of cultivation. On the contrary, when current density was higher than the threshold, connection of phycobilisome (PBS) and PS II core complexes was destroyed, PS II system of algae was damaged irreversibly, and algae could not survive thoroughly. The inactivation of M. aeruginosa by electrolysis can be attributed to irreversible separation of PBS from PS II core complexes and the damage of PS II of M. aeruginosa.

Substantial changes have occurred in hydrological situation of the Three Gorges Reservoir (TGR) after the operation of the Three Gorges project, as have the heavy metals (HMs) pollution characteristics. In this study, concentrations of Cu, Zn, Pb, Cr, and Cd in surface water and sediments of the TGR were determined during the water impoundment period (December 2015) and water drawdown period (June 2016). The index of geoaccumulation, principal component analysis (PCA), and correlation analysis were used to analyze HMs pollution characteristics. Results showed that HMs concentrations in surface water were much lower than the quality standards for drinking water and surface water of China. The pollution levels of HMs in sediments were nonpolluted for Cr, nonpolluted to moderately polluted for Cu, Zn, Pb, and moderately polluted for Cd. In the fluctuating backflow zone, HMs concentrations in sediments during the water drawdown period were lower than those during the water impoundment period, which was attributed to that faster flow velocity during the water drawdown period resulted in less deposition of suspended solids and faster release of HMs pollutants from sediments to water. HMs concentrations of sediments at sites M14 and M17 showed similar periodic changes to those at the fluctuating backflow zone, which might be attributed to the density-stratified flow in the adjacent upstream tributaries (Meixi River and Qinggan River, respectively). Correlation analysis and PCA analysis results showed that for the sediments, Cr came from natural sources, while Cu, Zn, Pb, and Cd mainly came from anthropogenic sources.

Bangong Lake,was an inland lake on the Tibetan Plateau, which was an international lake across China and India. The water chemistry characteristics were analyzed by testing the chemical composition of the lake water in Bangong Lake. The Gibbs diagram was used to explore the main controlling factors of lake water, and the main ion source of lake water was described in combination with the proportion of dissolved ions. The results showed that the center was brackish water and the east was fresh water of the Bangong Lake with a weak alkaline water. From the surface to the bottom, the temperature, dissolved oxygen and redox potential were decreasing, while the conductivity was increasing. The main cation of lake water was Na+, the main anion was Cl-, and the main chemical type was SO4-Cl-Na. The soluble ions in the central water were mainly controlled by evaporation and concentration, while the soluble ions in the eastern water were mainly controlled by rock weathering. The cations in the water were mainly derived from the silicate rock weathering and the dissolution of evaporite, and the anions was mainly derived from the dissolution of evaporite.

The explosive growth of water hyacinth had been a serious threat to the biodiversity of local ecosystems and the production, life and health of residents. It has become a malignantly invasive alien species in many countries and regions of the world. In this paper, biological characteristics and distribution, application in water pollution control, and application risk and control strategy in water pollution control of water hyacinth were summarized and elaborated.

A mean annual temperature increase has been recorded on the Yunnan–Guizhou Plateau of China during the last century. This temperature increase has been significantly greater since the 1950s. Thus, paleolimnological analyses may be utilized to better understand ecological responses to recent changing climate over decadal to centennial timescales, especially in regions with sparse lake monitoring data. Here, we present paleolimnological results from a 210Pb/137Cs-dated sediment core spanning approximately the last ~250 years from a remote, alpine, semi-closed oligotrophic lake (Lugu Lake) on the northwestern Yunnan–Guizhou Plateau. Sediment profiles of diatoms, geochemical variables (LOI550, TOC and C/N) and median grain size were analyzed and compared with the climate data (1951 AD–2010 AD) from the Lijiang weather station. Endogenous productivity of Lugu Lake has increased gradually over the last 30 years. The majority of diatom taxa encountered in the core are typical of alkaline oligotrophic lakes. Diatom assemblages were dominated by Cyclostephanos dubius, Cyclotella taxa, and fragilarioid taxa. Diatom species composition has changed significantly with three assemblage shifts at different scales over the ~250-year period. Diatom species diversity reveals a distinct increase before ~1970 AD, followed by a decline. In addition, a decreasing trend in diatom cell-size was consistent with recent warming trends. Redundancy analysis (RDA) shows that regional air temperature trends (annual, spring, summer, and winter) have played a significant role (p

Pluripotent stem cells act as an excellent cell source for disease therapy because of its specific characteristics of self-renewal and differentiation. Pluripotent stem cells are heterogeneous, consisting of naive stem cells as well as primed epiblast stem cells. However, the strategies and mechanisms of maintaining naive pluripotent stem cells remain unclear. In this study, we found that folic acid (FA) sustained mouse embryonic stem cell (ESC) pluripotency and enabled long-term maintenance of the naive state of ESCs under CHIR99021 conditions. Mechanistic experiments showed that STAT3 pathway partially mediated the effect of FA after which the interaction between STAT3 and importin α5 was enhanced. Meanwhile, MEK/ERK signaling also acted downstream of FA in maintaining ESC pluripotency. Furthermore, FA significantly promoted mouse somatic cell reprogramming. Overall, our study identified an effective chemical condition for maintaining homogeneous ESCs and highlighted the important roles of LIF/STAT3 and MEK/ERK signaling in naive ESC pluripotency.

Bioflocculants of Chlamydomonas reinhardtii were investigated under axenic conditions. C. reinhardtii was found to produce significant amounts of bioflocculants. Flocculating activity by C. reinhardtii began in the linear phase of growth and continued until the end of the stationary phase. The highest flocculating efficiency of the culture broth was 97.06%. The purified C. reinhardtii bioflocculant was composed of 42.1% (w/w) proteins, 48.3% carbohydrates, 8.7% lipids, and 0.01% nucleic acid. The optimum condition for bioflocculant production of C. reinhardtii was as follows: under temperature of 15A degrees C to 25A degrees C, pH 6-10 and illumination of 40-60 mu mol photons m(-2) s(-1). The bioflocculants produced by C. reinhardtii showed maximum activity in pH ranges from 2 to 10. The flocculating activity was significantly enhanced by the addition of CaCl2 as a co-flocculant at an optimal concentration of 4.5 mM.

Capability of three species of aquatic macrophytes to remediate pentachlorophenol (PCP)-contaminated sediments starting with initial concentration of 2,000 μg kg−1 dw (dry weight) was investigated. Negative effect of PCP on the plant growth, chlorophyll contents and root activities (p > 0.05) of the three species of aquatic macrophytes during remediation was not observed. PCP removal was significantly enhanced in the phytoremediated sediments in comparison with the control sediments after 90 days treatment (p

Plant-accelerated removal of BDE-209 from sediment by aquatic macrophyte Scirpus validus Vahl in the presence of a cationic-surfactant (CTAB), an anionic-surfactant (SDS), a nonionic-surfactant (Tween 80) and β-cyclodextrin (β-CD) at the concentrations ranged from 300 mg/kg to 1000 mg/kg were investigated. Significantly negative effect were not observed for the growth of S. validus in terms of plant height and stem diatemeter, which indicated that it is preferable for CTAB, SDS, Tween 80 and β-cyclodextrin to be utilized as the BDE-209 phytoremediation amendment. Furthermore, CTAB, SDS and Tween 80 in the certain concentrations significantly enhanced the phytoremediation efficiencies and 11.78-19.33% of increase in BDE-209 removal rates was obtained. Significantly enhance of BDE-209 phytoremediation efficiency was not observed in the added β-CD concentration ranges. Results obtained from this study provided some insight with regard to the feasibility of phytoremediation for BDE-209 contaminated sediments with addition of suitable solubilizers, especially Tween 80.