Distribution characteristics, sources and risk assessment of heavy metals in the surface sediments from the largest tributary of the Lancang River in the Tibet Plateau, China.

Angqu, positioned in the eastern expanse of the Tibet Plateau, claims the title of the largest tributary to the Lancang River. In October and December of 2018, in the sediment of Angqu, a comprehensive investigation was conducted on nine heavy metals-arsenic (As), manganese (Mn), chromium (Cr), cadmium (Cd), lead (Pb), mercury (Hg), copper (Cu), zinc (Zn), and nickel (Ni). This investigation aimed to scrutinize the spatial and temporal distribution patterns of these metals, assess the pollution status and ecological risks associated with the sediments, and delve into the sources contributing to their presence. The research results indicate that the average concentrations of As, Hg, and Cd in Angqu sediments exceed the soil background values of Tibet, while the concentrations of other heavy metals are below the soil background values of Tibet. Notably, arsenic poses potential ecological risks. In Angqu sediments, the concentrations of Mn, Cu, Ni, and Pb are generally higher in the wet season, but the seasonal variations of heavy metals in Angqu sediments are not significant. The sediments in the Angqu Basin are predominantly affected by mercury Hg, Cd, and As, with varying degrees of pollution at different sampling points. In the main stream of Angqu (City section), Hg pollution has reached above a moderate level, whereas As pollution near the tributary is only slightly polluted. The analysis of heavy metal sources reveals that there are five primary contributors to heavy metals in surface sediments of Angqu: parent material, agricultural activities, groundwater, atmospheric deposition, and other unidentified sources. Mn, Cr, Pb, and Ni are mainly derived from soil parent material, accounting for more than 50%. About 60.82% of As comes primarily from groundwater. Zn and Cd are mainly sourced from agricultural activities, accounting for 41.25% and 34.33%, respectively. Additionally, 20.6% of Hg originates from atmospheric deposition.

The pharmacological properties and corresponding mechanisms of farrerol: a comprehensive review.

CONTEXT: Farrerol, a typical natural flavanone isolated from the traditional Chinese herb 'Man-shan-hong' [Rhododendron dauricum L. (Ericaceae)] with phlegm-reducing and cough-relieving properties, is widely used in China for treating bronchitis and asthma. OBJECTIVE: To present the anti-inflammatory, antioxidant, vasoactive, antitumor, and antimicrobial effects of farrerol and its underlying molecular mechanisms. METHODS: The literature was reviewed by searching PubMed, Medline, Web of Knowledge, Scopus, and Google Scholar databases between 2011 and May 2021. The following key words were used: 'farrerol,' 'flavanone,' 'anti-inflammatory,' 'antioxidant,' 'vasoactive,' 'antitumor,' 'antimicrobial,' and 'molecular mechanisms'. RESULTS: Farrerol showed anti-inflammatory effects mainly mediated via the inhibition of interleukin (IL)-6/8, IL-1ß, tumour necrosis factor(TNF)-α, NF-κB, NO, COX-2, JNK1/2, AKT, PI3K, ERK1/2, p38, Keap-1, and TGF-1ß. Farrerol exhibited antioxidant effects by decreasing JNK, MDA, ROS, NOX4, Bax/Bcl-2, caspase-3, p-p38 MAPK, and GSK-3ß levels and enhancing Nrf2, GSH, SOD, GSH-Px, HO-1, NQO1, and p-ERK levels. The vasoactive effects of farrerol were also shown by the reduced α-SMA, NAD(P)H, p-ERK, p-Akt, mTOR, Jak2, Stat3, Bcl-2, and p38 levels, but increased OPN, occludin, ZO-1, eNOS, CaM, IP3R, and PLC levels. The antitumor effects of farrerol were evident from the reduced Bcl-2, Slug, Zeb-1, and vimentin levels but increased p27, ERK1/2, p38, caspase-9, Bax, and E-cadherin levels. Farrerol reduced α-toxin levels and increased NO production and NF-κB activity to impart antibacterial activity. CONCLUSIONS: This review article provides a theoretical basis for further studies on farrerol, with a view to develop and utilise farrerol for treating of vascular-related diseases in the future.

Physical literacy and health of Chinese medical students: the chain mediating role of physical activity and subjective well-being.

Background/objective: While Physical Literacy has been highlighted as a determinant in health in recent study, there is a dearth of studies examining its effect on physical health, and there is a little in the way of empirical data linking Physical Literacy to health outcomes. Accordingly, further empirical research is needed to clarify the mechanisms by which Physical Literacy affects physical health. The purpose of this study was to verify the role of medical students' Physical Literacy on Health-related quality of life as well as to explore the chain mediating role of Physical Activity and Subjective Well-being in it. Methods: This study utilized a cross-sectional study design. The Physical Literacy, Health-related Quality of Life, Physical Activity ratings, and Subjective Well-being of students at Shanxi Medical University were all measured using an online survey administered in September 2023. A total of 1968 valid questionnaires were returned. First, descriptive statistics and correlation analysis were performed using SPSS software. Second, PROCESS was used to test the mediating role. Finally, we used structural equation modeling (Amos) to test the model fit. Results: There is a significant correlation between all variables. After mediation effects analysis, we found that there were three indirect pathways of physical literacy on health-related quality of life: a single mediating effect of physical activity, a single mediating effect of subjective well-being, and a chained mediating effect of physical activity-subjective well-being. Conclusion: The mediating role of physical activity and subjective well-being on the relationship between physical literacy and health-related quality of life has been confirmed. Our research results support the integration of physical literacy into physical education teaching and the modification of curriculum content by physical education teachers as part of efforts to enhance students' physical activity levels, subjective well-being levels, and overall health. This study provides a new perspective for intervention in improving the health of medical students.

The Characteristics of Adsorption of Di-n-Butyl Phthalate by Surface Sediment from the Three Gorges Reservoir.

Phthalic acid esters (PAEs), recognized as endocrine disruptors, are identified as predominant organic pollutants in the Three Gorges Reservoir (TGR). Di-n-butyl phthalate (DBP), a representative PAE, has been extensively studied for its sources, distribution and ecological risks. However, there are few studies on the adsorption of DBP by sediment from the TGR, and the adsorption characteristics of surface sediment on DBP are not clear. Therefore, based on the actual sediment contents and particle sizes in the TGR, the kinetics and isothermal adsorption characteristics of surface sediment on DBP were investigated in this study. The results showed that the equilibrium time was 120 min, the adsorption kinetics were more in line with the pseudo-second-order kinetic model, and the sediment in water from the Yangtze River exhibited a higher adsorption rate and maximum adsorption amount on DBP than that observed in deionized water. Additionally, a decrease in DBP adsorption was observed with increasing sediment content, while sediment particle size and specific surface area had a slight influence. Analysis using SEM, TGA and FTIR revealed that organic matter on the sediment surface significantly contributed to DBP adsorption. This study contributes valuable insights into the adsorption characteristics of DBP by the surface sediment from the TGR, providing a scientific foundation for understanding the migration and transformation of DBP in this critical reservoir in China.

The mediating effect of 24-h time-use behaviors on the relationship between depression and mortality: A compositional mediation analysis for survival outcomes.

BACKGROUND: A compositional mediation model of survival outcomes was established to explore whether 24-h time-use behaviors mediate the relationship between depression and mortality. METHODS: 4137 adults from the National Health and Nutrition Examination Survey (NHANES 2005-2006) were followed up to 2019. Cox proportional hazards regression model was used to estimate the total effect of depression on mortality. Compositional data analysis was used to examine the relationship between 24-h time-use compositions and mortality. Furthermore, we constructed a compositional mediation model for survival outcomes to investigate the mediating effect of 24-h time-use behaviors on depression and mortality. RESULTS: Compared with participants without depression, depressive patients had a significantly higher risk of overall mortality (HR = 1.49, 95 % CI: 1.25,1.79), cardiovascular disease -specific mortality (HR =1.89, 95 % CI: (1.37,2.63)) and mortality from causes other than cardiovascular disease or cancer (HR = 1.62, 95 % CI: (1.25,2.08)). Physical activity, especially moderate-to-vigorous physical activity, significantly mediated the relationship between depression and all-cause and CVD-specific mortality. LIMITATIONS: Despite being a cohort study, the exposure and mediatiors were measured at the baseline. Further research is necessary to require a temporal order between the exposure and mediating variables. CONCLUSIONS: Our findings indicate that 24-h time-use behaviors link depression to mortality. In particular, increasing the time spent on physical activity can reduce the risk of death in patients with depression. This finding provides potential interventions for reducing the risk of death in patients with depression.

Down-regulation of connexin 43 contributes to structure and function of pulmonary artery in nicotine-administered mice.

Dysregulated connexin signaling is implicated in the pathophysiology of pulmonary artery hypertension (PAH). Nicotine affects pulmonary vascular remodeling. However, the potential mechanistic link between connexin signaling and nicotine-induced pulmonary artery remodeling remains unclear. We aimed to investigate the role of connexin 43 (Cx43) in pulmonary artery remodeling in nicotine-administered C57BL/6 J wild-type (WT) and Cx43 heterozygous (Cx43+/-) mice. Hemodynamic parameters and right ventricle pathology were assessed in the mice. Serum biochemical indices of hepatic and renal function were measured. The RT-PCR, immunofluorescence, and western blotting were conducted to evaluate Cx43 mRNA and protein levels. We performed histological staining to identify pulmonary arteries. Wire myography was used to examine contraction and relaxation responses in the pulmonary arteries. Pulmonary vascular permeability was assessed through Evans blue staining. Compared with the WT group, the Cx43+/- group showed lower Cx43 mRNA and protein expression in the pulmonary arteries (P < 0.01). Nicotine treatment significantly increased Cx43 expression (P < 0.01) and induced morphological changes in the pulmonary arteries (P < 0.01). Our findings suggest that Cx43 plays a crucial role in pulmonary artery reactivity and permeability in mice. Furthermore, downregulation of Cx43 expression may contribute to alterations in pulmonary artery structure and function.

Up-regulation of nPKC contributes to proliferation of mice pulmonary artery smooth muscle cells in hypoxia-induced pulmonary hypertension.

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 (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. 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. 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.

Spatiotemporal distribution dynamics of heavy metals in water, sediment, and zoobenthos in mainstream sections of the middle and lower Changjiang River.

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.

Spatial-temporal distribution characteristics and health risk assessment of heavy metals in surface water of the Three Gorges Reservoir, China.

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.

Spatial variations and periodic changes in heavy metals in surface water and sediments of the Three Gorges Reservoir, China.

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.

Influence of turbid flood water release on sediment deposition and phosphorus distribution in the bed sediment of the Three Gorges Reservoir, China.

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.

Efficiency and mechanism of the phytoremediation of decabromodiphenyl ether-contaminated sediments by aquatic macrophyte Scirpus validus.

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 ß-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.

Loss-tolerant measurement-device-independent quantum private queries.

Quantum private queries (QPQ) is an important cryptography protocol aiming to protect both the user's and database's privacy when the database is queried privately. Recently, a variety of practical QPQ protocols based on quantum key distribution (QKD) have been proposed. However, for QKD-based QPQ the user's imperfect detectors can be subjected to some detector- side-channel attacks launched by the dishonest owner of the database. Here, we present a simple example that shows how the detector-blinding attack can damage the security of QKD-based QPQ completely. To remove all the known and unknown detector side channels, we propose a solution of measurement-device-independent QPQ (MDI-QPQ) with single- photon sources. The security of the proposed protocol has been analyzed under some typical attacks. Moreover, we prove that its security is completely loss independent. The results show that practical QPQ will remain the same degree of privacy as before even with seriously uncharacterized detectors.

Folic Acid Supports Pluripotency and Reprogramming by Regulating LIF/STAT3 and MAPK/ERK Signaling.

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.

Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence characteristics of Microcystis aeruginosa.

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.

[Characteristics and comparative study of a new drinking-water defluoridation adsorbent Bio-F].

To evaluate the application potentiality pf a new type drinking-water defluoridation adsorbent Bio-F, comparative study on the defluoridation characteristics of common adsorbents activated alumina (AA), bone char (BC), activated clinoptilolite (AC) with Bio-F was conducted. The defluoridation characteristics under different conditions, such as particle diameter, pH, retention time, fluorine concentration, regeneration stability, were investigated by continuous-flow column experiments and static tests. The defluoridation efficiency of high fluoride underground water by four types of adsorbents was also compared. The results showed that F(-) adsorption kinetics of Bio-F fitted the Lagergren First-order equation (R2 = 0.9580). F(-) adsorption by Bio-F was found to fit the Langmuir adsorption isotherm (R2 = 0.9992). The results indicated that the static defluoridation capacity (DC) of Bio-F was 4.0883 mg x g(-1), which was about 1.8 folds and 5.8 folds of those of AA and AC respectively. DC of all four adsorbents was positively correlated with F(-) concentration and negatively correlated with particle size. High concentration of CO3(2-) and HCO3(-) reduced the DC of Bio-F (p < 0.05), while high concentration of Ca2+, NO3(-), HPO4(2-) favored defluoridation by Bio-F (p < 0.001). The optimal retention time of Bio-F was 3-4 min, which was less than that of AC (20 min) and AA (11 min). The DC of Bio-F remained relatively stable in pH 4.0-9.0 and in regeneration since the DC variation was not more than 15%. The above results indicated that Bio-F was superior to AA, BC and AC in drinking-water defluoridation.