Trade-induced atmospheric mercury deposition over China and implications for demand-side controls

Mercury (Hg) is of global concern because of its adverse effects on humans and the environment. In addition to long-range atmospheric transport, Hg emissions can be geographically relocated through economic trade. Here, we investigate the effect of China’s interregional trade on atmospheric Hg deposition over China, using an atmospheric transport model and multiregional input-output analysis. In general, total atmospheric Hg deposition over China is 408.8 Mg yr-1, and 32% of this is embodied in China’s interregional trade, with the hotspots occurring over Gansu, Henan, Hebei, and Yunnan provinces. Interprovincial trade considerably redistributes atmospheric Hg deposition over China, with a range in deposition flux from −104% to +28%. Developed regions, such as the Yangtze River Delta (Shanghai, Jiangsu, and Zhejiang) and Guangdong, avoid Hg deposition over their geographical boundaries, instead causing additional Hg deposition over developing provinces. Bilateral interaction among provinces is strong over some regions, suggesting a need for joint mitigation, such as the Jing-Jin-Ji region (Beijing, Tianjin, and Hebei) and the Yangtze River Delta. Transferring advanced technology from developed regions to their developing trade partners would be an effective measure to mitigate China’s Hg pollution. Our findings are relevant to interprovincial efforts to reduce trans-boundary Hg pollution in China

Crystal-field Engineering of Ultrabroadband Mid-infrared Emission in Co2+-doped Nano-chalcogenide Glass Composites

unable and ultrabroadband mid-infrared (MIR) emissions in the range of 2.5–4.5 μm are firstly reported from Co2+-doped nano-chalcogenide (ChG) glass composites. The composites embedded with a variety of binary (ZnS, CdS, ZnSe) and ternary (ZnCdS, ZnSSe) ChG nanocrystals (NCs) can be readily obtained by a simple one-step thermal annealing method. They are highly transparent in the near- and mid-infrared wavelength region. Low-cost and commercially available Er3+-doped fiber lasers can be used as the excitation source. By crystal-field engineering of the embedded NCs through cation- or anion-substitution, the emission properties of Co2+ including its emission peak wavelength and bandwidth can be tailored in a broad spectral range. The phenomena can be accounted for by crystal-field theory. Such nano-ChG composites, perfectly filling the 3–4 μm spectral gap between the oscillations of Cr2+ and Fe2+ doped IIVI ChG crystals, may find important MIR photonic applications (e.g., gas sensing), or can be used directly as an efficient pump source for Fe2+: IIVI crystals which are suffering from lack of pump sources

Perspectives and challenges of applying the water-food-energy nexus approach to lake eutrophication modelling

Embargo until August 4, 2023The water-food-energy (WFE) nexus is about balancing competing interests to secure the sustainability of services provided by interconnected sectors. Ignoring the interconnections could cause serious consequences. For example, eutrophication caused by overemphasizing on food production maximization could threaten water security. Worldwide eutrophication intensification is one of the most important causes of the lake water quality deteriorations. Water quality models are usually important decision making tools for policy makers. This study attempts to explore the possibilities of applying the WFE nexus concept into water quality models. We propose the most significant challenge is lack of a common modelling framework to streamline connections between up- and downstream models. As the most important water quality issue, eutrophication modeling should increase its visibility in the United Nations Sustainable Develop Goals.acceptedVersio

Third-order optical nonlinearity properties of CdCl2-modifed Ge–Sb–S chalcogenide glasses

We developed a new type of chalcohalide glasses with physicochemical and nonlinear optical properties that are tunable by composition. It is found that more than 60 mol.% CdCl2 heavy metal halide can be dissolved into the ternary Ge–Sb–S system and forming stable glasses. The visible-light transparency range is extended to shorter wavelengths with the addition of CdCl2, which is beneficial for the optical quality control and infra-red (IR) system alignment. The third-order optical nonlinearity (TONL) is studied using the femtosecond Z-scan method. The results show that both the nonlinear refractive index and two photon absorption co-efficient decrease with CdCl2. Benefiting from the favorable property-tailoring effects of CdCl2, the TONL figure of merit (FOM) can be improved to meet the requirement (FOM \u3c 1) for all-optical switching and IR photonic applications

Experimental study on the hydro-thermal-deformation characteristics of cement-stabilized soil exposed to freeze–thaw cycles

The exploration of the hydro-thermal characteristics and deformation behaviors of cement-stabilized soils is important for the prevention and control of freeze–thaw damage in cold region engineering. This study used six groups of cement-stabilized soil samples with different cement contents (i.e., 3%, 6%, 9%, 12%, 15%, and 18%) to investigate the variations in soil temperature, volumetric unfrozen water content, deformation, freezing temperature, and dry density. The results showed that the temperatures of the cement-stabilized soil samples during the freezing and thawing processes can be categorized into three stages and that the freezing temperature decreased with increasing cement content. Moreover, the cement content and ambient temperature significantly affected the volumetric unfrozen water content of the cement-stabilized soil samples during the freeze–thaw cycles, and the soil temperatures corresponding to the peak hysteresis degree were relatively consistent with the freezing temperature. The residual volumetric unfrozen water content primarily depended not only on the cement content but also on the freezing condition. Although the variations in volumetric unfrozen water contents during the freezing and thawing processes were similar, the ranges in temperature change differed significantly, particularly in the drastic phase transition zone. Additionally, adding cement into soils effectively inhibited deformation, mainly due to the dual positive effects of the liquid water reduction owing to hydration reaction and structure compaction owing to the filling of hydration products

Atmospheric Mercury Outflow from China and Interprovincial Trade.

Mercury (Hg) is characterized by its ability to migrate between continents and its adverse effects on human health, arousing great concern around the world. The transboundary transport of large anthropogenic Hg emissions from China has attracted particular attention, especially from neighboring countries. Here, we combine an atmospheric transport model, a mass budget analysis, and a multiregional input-output model to simulate the atmospheric Hg outflow from China and investigate the impacts of Chinese interprovincial trade on the outflow. The results show outflows of 423.0 Mg of anthropogenic Hg, consisting of 65.9% of the total Chinese anthropogenic emissions, from China in 2010. Chinese interprovincial trade promotes the transfer of atmospheric outflow from the eastern terrestrial boundary (-6.4 Mg year-1) to the western terrestrial boundary (+4.5 Mg year-1) and a net decrease in the atmospheric outflow for the whole boundary, reducing the chance of risks to foreign countries derived from transboundary Hg pollution from China. These impacts of interprovincial trade will be amplified due to the expected strengthened interprovincial trade in the future. The synergistic promotional effects of interprovincial trade versus Hg controls should be considered to reduce the transboundary Hg pollution from China

Analysis of an Imported Subgenotype C2 Strain of Human Enterovirus 71 in Beijing, China, 2015

Background: Subgenotype C4 of enterovirus 71 (EV71) is the predominant agent of Hand Foot and Mouth disease (HFMD) circulating in the mainland of China. For the first time, a subgenotype C2 of EV71 named SY30-2 was isolated from a HFMD case in Beijing, China. Since it is uncertain whether antibodies raised against subgenotype C4 of EV71 can protect C2 EV71, it is important to monitor and check the presence of cross-reactive antibodies against new EV71 subgenotypes. To find out the causes for the different NtAb, this study is to investigate the relationships between amino acid residue variations and cross-reactive antibodies against EV71 subgenotypes C2 and C4.Methods: Nucleotide and amino acid sequences from full-length genome sequence of SY30-2 were compared to EV71 reference strains. A microneutralization test was used to detect neutralizing antibody (NTAb) in the sera of subgenotype C4 of EV71 infected cases against SY30-2 and FY17 (a C4 isolate). The 3D structure of the viral capsid protein of SY30-2 was constructed.Results: Genome sequence and similarity plot analyses showed that SY30-2 shared the highest identity with subgenotype C2 of EV71 strains in every fragment of the genome. While the microneutralization test result showed that children infected with subgenotype C4 of EV71 had higher NTAb titers against FY17 than SY30-2 (p < 0.001). The amino acid sequence comparison revealed that four amino acid residues VP1-22, VP1-31, VP1-249 and VP3-93 were highly conserved in subgenotype C4 of EV71 compared with the corresponding amino acid residues on subgenotype C2 of EV71 (p < 0.05). Furthermore, the 3D-structure of viral capsid protein showed that VP1-22, VP1-31 and VP3-93 were located on the surface of virion.Conclusion: This is the first report of an EV71 subgenotype C2 isolated from HFMD in Beijing, China. Only a few antigenic variations on subgenotype C2 of EV71 could have led to a great decrease in NTAb titer. Thus, imported new genotypes and subgenotypes of EV71 should be closely monitored. The efficacy of available vaccines against new viruses should be evaluated as well

Preconditioning with Physiological Levels of Ethanol Protect Kidney against Ischemia/Reperfusion Injury by Modulating Oxidative Stress

Oxidative stress due to excessive production of reactive oxygen species (ROS) and subsequent lipid peroxidation plays a critical role in renal ischemia/reperfusion (IR) injury. The purpose of current study is to demonstrate the effect of antecedent ethanol exposure on IR-induced renal injury by modulation of oxidative stress.Bilateral renal warm IR was induced in male C57BL/6 mice after ethanol or saline administration. Blood ethanol concentration, kidney function, histological damage, inflammatory infiltration, cytokine production, oxidative stress, antioxidant capacity and Aldehyde dehydrogenase (ALDH) enzymatic activity were assessed to evaluate the impact of antecedent ethanol exposure on IR-induced renal injury.After bilateral kidney ischemia, mice preconditioned with physiological levels of ethanol displayed significantly preserved renal function along with less histological tubular damage as manifested by the reduced inflammatory infiltration and cytokine production. Mechanistic studies revealed that precondition of mice with physiological levels of ethanol 3 h before IR induction enhanced antioxidant capacity characterized by significantly higher superoxidase dismutase (SOD) activities. Our studies further demonstrated that ethanol pretreatment specifically increased ALDH2 activity, which then suppressed lipid peroxidation by promoting the detoxification of Malondialdehyde (MDA) and 4-hydroxynonenal (HNE).Our results provide first line of evidence indicating that antecedent ethanol exposure can provide protection for kidneys against IR-induced injury by enhancing antioxidant capacity and preventing lipid peroxidation. Therefore, ethanol precondition and ectopic ALDH2 activation could be potential therapeutic approaches to prevent renal IR injury relevant to various clinical conditions