40 research outputs found

    Phosphorus Species, Influencing and Release Risks Assessment in Mangrove Wetland Sediments of Dongzhai Harbor on Hainan Island, China

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    Mangrove wetlands are superior sites for the deposition of various pollutants, but they are also more susceptible to environmental contamination. To investigate the health threats of phosphorus to mangrove ecosystems, this study presents the distribution, chemical speciation and factors influencing phosphorus (P) forms in 38 surface sediments from the mangrove wetlands of Dongzhai Harbor on Hainan Island, China. P forms were measured using the sequential extraction (SEDEX) procedures. The results showed that the total phosphorus content in the sediment was at a high level, and there was a significant spatial variability of phosphorus in each form. Among them, inorganic phosphorus accounted for 74.64% of the total phosphorus, and organic phosphorus accounted for 25.35% of the total phosphorus. Among the inorganic phosphorus, detrital limestone phosphorus and Ca-bound phosphorus were dominant, while the content of exchangeable phosphorus and Fe-bound phosphorus had a smaller percentage. The concentration of biologically available phosphorus, ranged from 1.76 umol/g to 18.57 umol/g, and the Fe-bound and organic forms of phosphorus had a controlling effect on it. Based on Corg/OP, N/P and land use surveys, it was concluded that phosphorus was mainly an exogenous input. The correlation analysis concluded that the main sources of phosphorus in the study area are agriculture and aquaculture. The development of agriculture and aquaculture led to moderate levels of phosphorus pollution in the study area as a whole, with more serious a phosphorus pollution at the wetland park in the southeast corner of Dongzhai Harbor and in the western areas, with lush vegetation and developed river systems, mainly influenced by human activities, topography, vegetation and water system conditions

    Oleoylethanolamide Protects against Acute Ischemic Stroke by Promoting PPARα-Mediated Microglia/Macrophage M2 Polarization

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    Oleoylethanolamide (OEA) has been demonstrated to be a feasible protectant in ischemic stroke. However, the mechanism for OEA-afforded neuroprotection remains elusive. The present study aimed to investigate the neuroprotective effects of OEA on peroxisome proliferator-activated receptor α (PPARα)-mediated microglia M2 polarization after cerebral ischemia. Transient middle cerebral artery occlusion (tMCAO) was induced for 1 h in wild-type (WT) or PPARα-knock-out (KO) mice. Mouse small glioma cells (BV2) microglia and primary microglia cultures were used to evaluate the direct effect of OEA on microglia. A coculture system was used to further elucidate the effect of OEA on microglial polarization and ischemic neurons’ fate. OEA promoted the microglia switch from an inflammatory M1 phenotype to the protective M2 phenotype and enhanced the binding of PPARα with the arginase1 (Arg1) and Ym1 promoter in WT mice but not in KO mice after MCAO. Notably, the increased M2 microglia caused by OEA treatment were strongly linked to neuron survival after ischemic stroke. In vitro studies confirmed that OEA shifted BV2 microglia from (lipopolysaccharide) LPS-induced M1-like to M2-like phenotype through PPARα. Additionally, the activation of PPARα in primary microglia by OEA led to an M2 protective phenotype that enhanced neuronal survival against oxygen-glucose deprivation (OGD) in the coculture systems. Our findings demonstrate the novel effects of OEA in enhancing microglia M2 polarization to protect neighboring neurons by activating the PPARα signal, which is a new mechanism of OEA against cerebral ischemic injury. Therefore, OEA might be a promising therapeutic drug for stroke and targeting PPARα-mediated M2 microglia may represent a new strategy to treat ischemic stroke

    Rare-earth doped (K0.5Na0.5)NbO3 multifunctional ceramics

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    A novel PtRuIr nanoclusters synthesized by selectively electrodepositing Ir on PtRu as highly active bifunctional electrocatalysts for oxygen evolution and reduction

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    To promote development of the unitized regenerative fuel cell, a new energy conversion-storage device, it is essential to look for a bifunctional catalyst with high efficiency and catalytic properties for oxygen evolution and reduction reactions. Herein, a novel PtRuIr electrocatalyst has been synthesized by a pulse electrodeposition method with selectively electrodepositing Ir on PtRu nanoclusters. The prepared catalysts were characterized by electrochemical analysis, scanning electron microscopy and energy dispersive spectrometer. The experimental results show that the PtRuIr catalyst with 10 mol% of Ir exhibits significantiy higher oxygen evolution and reduction currents compared to the PtRu and the PtRuIr catalysts with other contents of Ir, which is also supported by the electrochemical impedance data. In addition, a single water electrolysis cell and a H-2/O(2)fuel cell were performed simultaneously to evaluate the oxygen evolution and reduction performances, respectively, of the novel catalyst. The optimized catalyst with 90 mol% PtRu and 10mol% Ir shows higher oxygen evolution reactivity current density and higher round-trip efficiency in the water electrolysis single cell, and in the meantime, it also exhibits higher oxygen reduction current density and higher power density in the fuel cell, compared to those of the PtRu catalyst.</p

    sj-docx-1-npx-10.1177_1934578X241242281 - Supplemental material for Network Pharmacology and In Vivo Validation to Explore the Potential Active Ingredients and Mechanisms of Ziyin Buyang Formula in Diminished Ovarian Reserve

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    Supplemental material, sj-docx-1-npx-10.1177_1934578X241242281 for Network Pharmacology and In Vivo Validation to Explore the Potential Active Ingredients and Mechanisms of Ziyin Buyang Formula in Diminished Ovarian Reserve by Ruxin Wang, Haixia Huang, Wenchen Du, Guicheng Xia and Yong Tan in Natural Product Communications</p

    Effect of pulse electrodeposition parameters on electrocatalytic the activity of methanol oxidation and morphology of Pt/C catalyst for direct methanol fuel cells

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    The electrodeposition technique for preparing direct methanol fuel cell electrodes has been developed to increase the Pt utilization and lower the Pt loading. The performance of the Pt/C electrode for methanol oxidation reaction (MOR) was optimized by adjusting the electrodeposition parameters such as applied electrical signal types, ratios of t(on)/t(off) deposition temperatures, and electrolyte concentrations, systematically. Furthermore, the effects of two kinds of additives, i.e. polyethylene glycol (PEG) and sodium dodecyl sulfonate (SDS), on the catalytic performance and morphology of Pt catalyst were investigated for MOR by SEM, XRD, cyclic voltammetry and linear sweep voltammetry. The results show that the optimal Pt catalyst has been prepared by the square wave current method with t(on)/t(off) of 1 s/5 s at 30 degrees C in a 1.0 mmol L-1 H2PtCl6 solution with a 10(-4) mmol L-1 PEG additive. Moreover, the effect of the additive type and amount on the formation mechanism of the Pt crystallite morphology has also been discussed. From the results, introducing additives into the deposition solution in the pulse electrodeposition process is useful for designing and fabricating electrocatalytic electrodes for direct methanol fuel cells.</p

    Why do older adults living alone in cities cease seeking assistance? A qualitative study in China

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    AbstractBackgroundAgainst the background of an aging population, older adults living alone in cities are increasingly dependent. However, their use of home and community-based services in China is unsatisfactory. This study attempted to figure out why older adults living alone in cities do not actively seek assistance in China.MethodsIn-depth interviews were conducted. A total of 29 older adults were recruited. Content analysis was used to analyze the interview data.ResultsThree themes were identified. (1) Desire for independence, despite hardship: The lives of older adults involve many inconveniences, but they preferred to solve problems by themselves, instead of asking for help; (2) Desire to not overburden jiaren (meaning family in Chinese): older adults did not want to disturb families or burden children with caring responsibilities. Moreover, previous experience of failing to obtain care made them reluctant to seek help from jiaren; (3) Desire to not bother wairen (meaning people other than family in Chinese): The lack of trust caused by being unfamiliar with wairen, and the fear of being a burden to others if they were not able to reciprocate, made older adults reluctant to seek help from wairen.ConclusionsChanges in social, economic, and demographic structures have led to gradual failure of family care. Older adults accustomed to an “acquaintance society” have not yet adapted to seeking help from the community. When addressing the problem of care for older adults living alone in cities, it is important to focus on the profound impact of social change.</jats:sec
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