181 research outputs found

    The α1‐adrenergic receptor is involved in hepcidin upregulation induced by adrenaline and norepinephrine via the STAT3 pathway

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    Elevated body iron stores are associated with hypertension progression, while hypertension is associated with elevated plasma catecholamine levels in patients. However, there is a gap in our understanding of the connection between catecholamines and iron regulation. Hepcidin is a key iron‐regulatory hormone, which maintains body iron balance. In the present study, we investigated the effects of adrenaline (AD) and norepinephrine (NE) on hepatic hepcidin regulation. Mice were treated with AD, NE, phenylephrine (PE, α1‐adrenergic receptor agonist), prazosin (PZ, α1‐adrenergic receptor antagonist), and/or propranolol (Pro, ÎČ‐adrenergic receptor antagonist). The levels of hepcidin, as well as signal transducer and activator of transcription 3 (STAT3), ferroportin 1 (FPN1), and ferritin‐light (Ft‐L) protein in the liver or spleen, were assessed. Six hours after AD, NE, or PE treatment, hepatic hepcidin mRNA levels increased. Pretreatment with PZ, but not Pro, abolished the effects of AD or NE on STAT3 phosphorylation and hepatic hepcidin expression. When mice were treated with AD or NE continuously for 7 days, an increase in hepatic hepcidin mRNA levels and serum hepcidin concentration was also observed. Meanwhile, the expected downstream effects of elevated hepcidin, namely decreased FPN1 expression and increased Ft‐L protein and non‐heme iron concentrations in the spleen, were observed after the continuous AD or NE treatments. Taken together, we found that AD or NE increase hepatic hepcidin expression via the α1‐adrenergic receptor and STAT3 pathways in mice. The elevated hepatic hepcidin decreased FPN1 levels in the spleen, likely causing the increased iron accumulation in the spleen

    Influence of Electrolyte Refreshing on the Photoelectrochemical Performance of Fiber-Shaped Dye-Sensitized Solar Cells

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    Given the convenient sealing of fiber-shaped dye-sensitized solar cells (FDSSCs), the electrolyte refreshing effect on the photo-electrochemical performance of FDSSCs was studied. The electron transport and interfacial recombination kinetics were also systematically investigated by electrochemical impedance spectroscopy. With increased electrolyte refreshing times from 0 to 10, the open-circuit voltage (Voc) and fill factor (FF) increased, whereas the photocurrent density (Jsc) and power conversion efficiency (PCE) significantly decreased. The increased Voc was mainly ascribed to the electron recombination resistance (Rct, WE) at the TiO2/electrolyte interface and electron lifetime. The decreased Jsc and PCE were due to dye desorption and the increase of series resistance. Further investigation proved that Li+ played a vital role in increasing Voc as electrolyte refreshing and Li+ had more significant impact than TBP (tert-butyl pyridine) on maintaining high Voc

    Simultaneous Determination of Malachite Green, Chloramphenicols, Sulfonamides, and Fluoroquinolones Residues in Fish by Liquid Chromatography-Mass Spectrometry

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    A fast-analytical method using simplified extraction has been developed for the simultaneous determination of 42 compounds from 4 different classes of veterinary drugs (amphenicols, triphenylmethane, fluoroquinolones, and sulfonamides) in fish by reverse phase liquid chromatography-tandem mass spectrometry. The selection of extraction reagents was optimized using different types of microfiltration membrane, mobile phase, and LC column. Samples were extracted using 0.4% hydrochloric acid in acetonitrile and ethyl acetate and then were cleaned up using solid-phase extraction Cleanert Alumina N columns (500 mg) and Oasis hydrophilic-lipophilic balance (HLB) cartridges. The chromatographic separation was performed on a XR-ODS C8 column using a mobile phase of (A) 0.1% formic acid and 2 mM ammonium acetate and (B) 0.1% formic acid acetonitrile at a flow rate of 0.25 mL·min−1. The results indicated 67.7–112.8% recovery of 42 compounds with an intra- and interday relative standard deviations less than 10%. The limits of quantification for analytes were in the range of 0.3–1.0 Όg kg−1 for samples which were satisfactory to support future surveillance monitoring. The method applicability was checked by analyzing 30 fish samples collected from local markets. Two fish samples surpassed the established MRL of 100 Όg kg−1 with values of 104 Όg kg−1 and 112 Όg kg−1

    Pathways from payments for ecosystem services program to socioeconomic outcomes

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    Payment for ecosystem services (PES) is a widely accepted policy tool for achieving environmental conservation and socioeconomic development goals. However, the mechanisms through which PES programs affect socio-economic outcomes remain elusive. Here, we use a framework which integrates links between PES programs, livelihood activities, and socioeconomic outcomes, to determine how China's Grain-to-Green Program (GTGP) has affected the incomes of participating households in the Yanhe watershed of the Loess Plateau. The results show that although the total effect of the GTGP on household income is not statistically significant, there are still two significant pathways. Through the analysis we found that implementation of the GTGP significantly increased the participations in local non-farm jobs, which leads to increased household incomes. Based on our findings, we suggest several ways of improving the socioeconomic outcomes of the GTGP through increasing non-farm work benefit of participating households, maximizing the positive effect of economic forest, and reducing the reliance of households on income from crop production. Our study provides a template for revealing the underlying pathways to socioeconomic outcomes of PES programs-crucial knowledge if we are to design and implement better PES programs and achieve the desired environmental conservation and poverty reduction goals

    Effect of Cobalt on Microstructure and Wear Resistance of Ni-Based Alloy Coating Fabricated by Laser Cladding

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    Ni-based alloy powders with different contents of cobalt (Co) have been deposited on a 42CrMo steel substrate surface using a fiber laser. The effects of Co content on the microstructure, composition, hardness, and wear properties of the claddings were studied by scanning electron microscopy (SEM), an electron probe microanalyzer (EPMA), X-ray diffraction (XRD), a hardness tester, and a wear tester. The results show that the phases in the cladding layers are mainly Îł, M7(C, B)3, M23(C, B)6, and M2B. With the increase in Co content, the amounts of M7(C, B)3, M23(C, B)6, and M2B gradually decrease, and the width of the eutectic structure in the cladding layer also gradually decreases. The microhardness decreases but the wear resistance of the cladding layer gradually improves with the increase of Co content. The wear resistance of the NiCo30 cladding layer is 3.6 times that of the NiCo00 cladding layer. With the increase of Co content, the wear mechanism of the cladding layer is changed from abrasive wear to adhesive wear

    A connectivity-based assessment framework for river basin ecosystem service management

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    Conflicts between increasing ecosystem services (ESs) demand and limited or even decreased natural capital hinders the sustainable development of river basins worldwide. The main reason for the conflicts is that human interventions have seriously decoupled the original harmonious relationship between humans and nature. In this review, we proposed a network connectivity-based assessment framework for river basin ES management which aims to quantify the connections among ecosystems, ESs, ES beneficiaries, ES management organizations and external drives. Construction of the network is based on how multiple ESs are provided and consumed among multiple beneficiaries, to cope with external drivers and inform management efforts. This framework can be used to identify if management intervention is needed for keeping river basin ESs and to address any changes in the interactive socio-ecological system for more sustainable river basin ES management
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