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Hypoxia-induced pulmonary microvascular endothelial cell (PMVEC) monolayers hyperpermeability is vital for vascular leakage, which participates in vascular diseases, such as acute lung injury (ALI) and high-altitude pulmonary edema (HAPE). We previously observed that PMVEC permeability was markedly elevated in hypoxia when cocultured with primary type II alveolar epithelial cells (AECII) in which isthmin1 (ISM1) was highly upregulated. However, whether the upregulation of ISM1 plays a role in hypoxia-induced PMVEC hyperpermeability is unclear. In this study, we assessed the role of AECII-derived ISM1 in hypoxia-induced PMVEC hyperpermeability with an AECII/PMVEC coculture system and uncovered the underlying mechanism whereby hypoxia stimulates ISM1 gene expression. We found that ISM1 gene expression was upregulated in cultured AECII cells exposed to hypoxia (3% O2) and that AECII-derived ISM1 participated in hypoxia-induced hyperpermeability of PMVEC monolayers, as small interference RNA (siRNA)-mediated knockdown of ISM1 in AECII markedly attenuated the increase in PMVEC permeability in coculture system under hypoxia. In addition, we confirmed that ISM1 was regulated by hypoxia-inducible factor-1α (HIF1α) according to the evidence that silencing of HIF1α inhibited the hypoxia-mediated upregulation of ISM1. Mechanismly, overexpression of HIF1α transcriptionally activated ISM1 gene expression by directly binding to the conserved regulatory elements upstream of the ism1 locus. We identified a novel HIF-1-target gene ISM1, which involves in hyperpermeability of pulmonary microvascular endothelial cell monolayers under hypoxia. Our in vitro cell experiments implied that the upregulated ISM1 derived from alveolar epithelium might be a vital modulator in hypoxia-induced endothelial hyperpermeability and thereby implicates with hypoxic pulmonary-related diseases.

In this paper, the antimicrobial effect of inert flue gas on indicator microorganisms in ballast water was investigated based on a 265h test. The inert flue gas consists of nitrogen (N_2) and carbon dioxide (CO_2) the microorganisms include Chlorella and Escherichia coli. Within the scope of the test, the killing effect of the microbes treated by combining N_2 and CO_2 was higher than that of using only either N_2 or CO_2. When the dissolved oxygen concentration in the ballast water was 0.5 mg/L and the pH value was 6, the killing effect was the highest. At this time, the mortality rate of Chlorella sp. and E. coli reached 99.99%, and 99.98%, respectively. After the experiment, property of the ballast water treated by N_2 and CO_2 were analyzed. The dissolved organic carbon concentration was lower than the recommended minimum concentration of 5 mg/L. The concentration of particulate organic carbon was higher than the standard value of 0.3%.The experiment proposes a new method for ballast water treatment of large ocean-going vessels in the future.

Chorioamnionitis (CAM), as a common intrauterine infectious disease, is the leading cause of premature birth, stillbirth, neonatal infection and sepsis. The formyl peptide receptor 2 (FPR2) is a member of GPCRs widely distributed in a variety of tissues and is associated with many inflammatory diseases. With the discovery of FPR2 in human placenta, the possibility of exploring the function of FPR2 in obstetrics is evolving. The Resolvin D1 (RvD1) plays an important role in the resolution of inflammation by combining with FPR2. In this study, we evaluated the role of FPR2 and RvD1 in CAM, not only in the human placenta but also in mouse models. The expression of FPR2 increased in the placenta of CAM patients and the downstream PPARγ/NF‐κB signalling changed accordingly. Moreover, Fpr2−/− mice were highly susceptible to LPS, displaying a worse CAM symptom, compared with WT mice. By establishing a model of trophoblast inflammation in vitro, it was confirmed that RvD1 rescued the effect of LPS on inflammation by combining with FPR2 and its downstream PPARγ/NF‐κB pathway. Otherwise, RvD1 improved the preterm labour in a mouse model of CAM induced by LPS. Altogether, these findings show that RvD1 alleviated the inflammation of trophoblast in vivo and in vitro through FPR2/PPARγ/NF‐κB pathway, suggesting RvD1/FPR2 might be a novel therapeutic strategy to alleviate CAM.

Previous studies have demonstrated that silica nanoparticle (SiNP) exposure induces pulmonary and cardiovascular diseases, yet their transportation and degradation in vivo have not been fully elucidated. From the perspective of reproduction, this study was implemented to examine the uterine accumulation of SiNP and explore its reproductive toxicity and pathogenic mechanisms. First, we coupled FITC onto SiNPs and intratracheally instilled them into pregnant mice on the fifth gestational day, and the toxic effect of SiNP was evaluated in vitro and in vivo. It was found that SiNP penetrated the trophoblast membrane, leading to apoptosis and suppression of cell proliferation, tube formation, and invasion in a dose-dependent manner. Mechanistically, SiNP dysregulated the expression of Scd1, Slc27a1, and Cpt1a, and induced over synthesis and efflux obstruction of fatty acid through the PPARγ signaling pathway. The downregulation of Caspase-3 triggered apoptosis of trophoblast, which was causally associated with intracellular fatty acid accumulation as revealed by the correlation analysis. Besides, SiNP induced uterine inflammation in vivo, which aggravated with the observation prolongation within 24 h. Overall, SiNPs were visualized by coupling with FITC, and the uterine accumulation of SiNP induced fatty acid metabolic disorder, biological dysfunction, and trophoblast apoptosis, which were mediated in part by the PPARγ signaling pathway. These findings would contribute to understanding the environmental impacts of SiNP better, as well as the development of control measures for environmental pollution.

In this paper, composites of poly (3,4-ethylenedioxythiophene) (PEDOT) and sulfonated cellulose (SC) were prepared by oxidative polymerization both in CHCl3 and H2O using different SC contents. The structures of composites (PEDOT/SC) were characterized by Ultraviolet–Visible absorption spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Electrochemical sensing using a PEDOT/SC-modified electrode was performed by the differential pulse voltammetry method. The results indicate that SC acted as a soft template for the formation of fibrous composites. Doping PEDOT with SC affected the conjugation degree and crystallinity of the resulting composites. The results showed that the PEDOT/SC composites obtained in H2O exhibited a higher electrochemical response than those produced in CHCl3. The composites obtained using 5 mg/mL SC in both reaction media had the best electrochemical performance. The electrochemical analysis showed that the limit of detection (LOD) for paracetamol was 0.258 μM and 0.0742 μM, with linear ranges of 0.02–4000 μM and 0.08–1580 μM for composites obtained using 5 mg/mL SC in H2O and CHCl3, respectively.

Two unique lanthanide coordination polymers, namely, {[Ln2(μ3-OH)2(Tfpht)2 (H2O)2·0.5bipy]}n (Ln = Gd (1) and Eu (2), H2Tfpht = 3,4,5,6-Tetrafluorophthalic acid, bipy = 4,4′-bipyridine) have been afforded successfully. The coordination polymers 1 and 2 are isostructural and have the same phase, both crystallizing in the triclinic system, with space group of P−1. They both exhibit one-dimensional (1-D) ribbon-double chains composed of trinuclear lanthanide clusters bridged by μ3-hydroxyl bridges and carboxyl oxygen atoms of Tfpht2− ligands, and the chains are further linked by hydrogen bonding interactions to give rise to a 2-D corrugated layer. The solid state luminescence emission spectra of coordination polymer 1 is based on the H2Tfpht acid ligand, whereas 2 displays the characteristic f-f transitions of Eu(III) ions. The direct-current (dc) magnetic susceptibility studies reveal the weak ferromagnetic interaction between the Gd(III) ions in coordination polymer 1.

Objective MiR-499 has been reported to be expressed only in cardiomyocytes, and its expression would increase after acute myocardial infarction (AMI). miR-499 plays a role in the process of cardiomyocytes injury induced by hypoxia/reoxygenation (H/R), however, it still remains unclear. Results Hypoxia inhibited miR-499-5p expression and H/R induced apoptosis. SOX6 was a target gene of miR-499-5p, and high expression of miR-499-5p inhibited the expression of SOX6. MiR-499-5p reduced H9c2 cells injury by inhibiting the expression of SOX6, overexpression of which could reverse the effect of miR-499-5p on H9c2 cells. MiR-499-5p inhibited the levels of LDH and MDA, while overexpression of miR-499-5p inhibited H/R-induced cell apoptosis. MiR-499-5p could up-regulate the level of Bcl-2 and down-regulate the expression levels of Bax and caspase-3. However, SOX6 partially reversed these effects of miR-499-5p. Conclusion We proved that miR-499-5p inhibited H/R-induced cardiomyocytes injury by targeting SOX6. Our results suggested that miR-499-5p/SOX6 pathway may present a potential therapeutic target for the treatment of AMI.

In this work, three Schiff base derivatives with large conjugated system have been elaborately designed and synthesized, in which bithienyl (1), pyrenyl (2) and anthryl (3) connect an azo moiety (N=N) monomer through conjugation linkage (C=N), respectively. Their third-order nonlinear optical (NLO) properties are systematically investigated by performing the picosecond-pulsed Z-scan measurements at the wavelength of 532 nm and femtosecond-pulsed Z-scan measurements at the wavelength of 600 nm. The pump-probe measurements and the linear dependence between the amplitude of transmittance change and different laser energy indicate that the nonlinearity is originated from pure two-photon absorption (2PA) behavior. Among them, compound 1 with the bithiophene group has a larger two-photon absorption cross section up to 8.90 × 104 GM (ps). The reason may be that the electron-rich bithiophene group with lower delocalization energy improves electron transition. In addition, excellent optical limiting (OL) behaviors of the three Schiff base derivatives are observed under ps laser excitations at 532 nm wavelength, which resulted from 2PA induced reverse saturation absorption (RSA). All the experimental results manifest that these compounds could be used as potential NLO materials.

Given the long-term potential risk of arsenic (As)-contaminated agricultural soil to public health, the redistribution of iron (Fe) and immobilization of As within the unsaturation zone during irrigation and consequent water table fluctuations were studied via a column experiment and corresponding geochemical modeling. Experimental results show that As and Fe accumulated significantly at the top of the column during irrigation. A tremendous increase in As and Fe accumulation rates exists after water table recovery. It was deduced that Fe(II) and As(III) were oxidized directly by O2 at the period of low water table. But the production of hydroxyl radical (OH) was promoted at the period of high water table due to the oxidation of adsorbed Fe(II). The generated OH further accelerate the oxidation of Fe(II) and As(III). Moreover, the combination of As and Fe is more stronger at the top of the column due to the transformation of combined states of As from surface complexation into surface precipitation with the growth of Fe(III) minerals. This study details the processes and mechanisms of As and Fe immobilization within the unsaturation zone during different irrigation periods and accordingly provides some insights to mitigate As accumulation in topsoil.

Magnesium-silicate-hydrate (M-S-H) cement has emerged as an alternative binder with potentially lower energy requirements and emissions. Due to the intrinsically low pH values of its matrix, however, normal steel reinforcement is not appropriate for M-S-H system. To toughen the matrix and to overcome the brittle nature of the material, a new strain hardening magnesium-silicate-hydrate composite (SHMSHC) is developed for the first time by incorporating 2 vol% short and randomly oriented polyvinyl alcohol (PVA) microfibers. The resulting SHMSHC exhibits significant strain hardening with a tensile strain capacity of more than 3%, a compressive strength beyond 50 MPa and a tensile strength of around 3 MPa. Remarkably, saturated multiple cracking with a tight crack width less than 10 μm invisible to the human naked eyes was observed. The newly developed SHMSHC addresses the fundamental challenge of M-S-H binder and is expected to widen possible application areas of M-S-H system. Ministry of Education (MOE) The authors acknowledge the financial support from the Singapore MOE Academic Research Fund Tier 2 (MOE2017-T2-1-087 (S)).

Extensive application of nanomaterials has dramatically increased the risk of silica nanoparticle (SiNP, SiO2) exposure, yet their biological effect on reproduction has not been fully elucidated. By tracking the uterine biodistribution of SiNP in pregnant mice, this study was conducted to evaluate the biological effect of SiNP on reproduction. First, SiNP was conjugated with FITC, and then the FITC-SiNP was administrated to trophoblast (100 µg/mL, 24 h) in vitro and pregnant mice (0.25 mg/mouse, 2–24 h) in vivo. It was found that the FITC-SiNP was internalized by trophoblast and deposited in the uterus. The internalization of SiNP caused trophoblast dysfunction and apoptosis, while SiNP accumulation in the uterus induced diffuse inflammatory infiltration. The genome-wide alteration of gene expression was studied by high throughput sequencing analysis, where 75 genes were found to be dysregulated after SiNP exposure, among which ACOT2, SCD1, and CPT1A were demonstrated to regulate the biosynthesis of unsaturated fatty acids. Moreover, the suppression of unsaturated fatty acids caused mitochondrial overload of long-chain fatty acyl-CoA (LACoA), which further induced both trophoblast apoptosis and endometrial inflammation. In conclusion, the successful conjugation of FITC onto SiNP facilitated the tracking of SiNP in vitro and in vivo, while exposure to FITC-SiNP induced uterine metabolic disorder, which was regulated by the ACOT/CPT1A/SCD1 axis through the biosynthesis of unsaturated fatty acids signaling pathway.

Silica nanoparticles (SiNPs) have drawn considerable attention due to their environmental health effects, while enhanced understanding of metabolic disorders has provided insight into related diseases. To investigate the impacts of SiNPs exposure on reproduction and reveal their pathogenic mechanisms, this study was designed and conducted from a metabolic perspective. First, fluorescein isothiocyanate (FITC)-SiNPs were chemically synthesized and applied to track SiNPs in vitro and in vivo. Next, 30 pregnant mice were intratracheally instilled with 1.25 mg of SiNPs/mouse, then sacrificed 24 h post-treatment. We found that SiNPs penetrated the trophoblast membrane, triggering apoptosis and inhibiting cell proliferation, invasion, and tube formation in a dose-dependent manner. Mechanistically, SiNPs dysregulated phosphofructokinase (Pfkl) and fructose-bisphosphatase 2 (Fbp2) and induced glucose depletion and pyruvate accumulation via the pentose phosphate pathway. Besides, the downregulation of caspase-3 suggested a causal relationship between pyruvate accumulation, pentose phosphate pathway activation, and cell apoptosis. Pfkl and Fbp2 was also dysregulated in vivo, and the uterine inflammation aggravated in a time-dependent manner. In conclusion, SiNPs triggered acute cytotoxicity and uterine inflammation by inducing glucose depletion and pyruvate overload in trophoblasts, which were mediated in part by Pfkl and Fbp2 via the pentose phosphate pathway.

Exposure to silica nanoparticles (SiNPs) has been suggested to cause physical disorders, yet the effects of SiNPs on female reproduction have not been illustrated. This study was implemented to explore the reproductive toxicity of SiNPs on female and reveal its underlying mechanisms. Methodologically, the fluorescein isothiocyanate (FITC)-SiNPs were synthesized by coupling with FITC and then used to track the biodistribution of SiNPs in vitro and in vivo. In total, 30 mice were intratracheally injected 0.25 g of FITC-SiNPs, and 6 mice injected with the same volume of saline were used as controls. The results showed that SiNPs penetrated the cellular membrane, triggering apoptosis and inhibiting proliferation, tube formation, and invasion of trophoblast. Mechanistically, SiNPs was demonstrated to dysregulate Fbp2, Cpt1a, Scd1, and Pfkl, and further induced accumulation of pyruvate and fatty acid in mitochondria through the AMPK signaling pathway, which finally activated the Caspase-3-dependent apoptosis. Consistently, the similar alterations of these genes were detected in vivo, and the uterine inflammatory infiltration aggravated with the extension of the observation duration. These results suggested that SiNPs induced trophoblast apoptosis and uterine inflammation, and ultimately caused acute reproductive toxicity on female. The underlying mechanism might be explained by the dysregulation of Fbp2/Cpt1a/Pfkl/Scd1 axis, which promoted the overload of glucose and lipid through the AMPK signaling pathway. These findings were of great significance to guide a comprehensive understanding of the reproductive toxicity of SiNPs as well as the development of environmental standards.

Intake of groundwater with arsenic (As) concentrations exceeding the World Health Organization standard of 10 μg L−1 adversely impacts over 100 million people worldwide. Geogenic As contaminated groundwater within central Yangtze River Basin has recently been reported, but the variations within different depths of aquifers are not commonly observed and the processes controlling As variations have yet to be resolved. Here we report the significant As variations within two different depths (10 m and 25 m) of shallow multi-level alluvial aquifers at Jianghan Plain, a floodplain in the central Yangtze River Basin, which is also a recently discovered geogenic As affected area with cases of waterborne arsenicosis. The multi-year monitoring of aquifer chemistry results show that the As concentrations increase with the Fe(II) concentrations when As contents are relatively lower (

Fluoride enrichment in groundwater at the North China Plain (NCP) is posing a potential health risk to human being. To better understand the enrichment mechanism of fluoride in the groundwater systems, the groundwater, sediments samples and pore water compacted from clayey sediments were collected to perform the chemistry analysis and geochemical inverse modeling. The results showed that fluoride concentration in groundwater from the NCP has a range of 0.38–7.35 mg/L, and 67.8% of groundwater samples have the fluoride concentration higher than 1.5 mg/L. High fluoride groundwater was mainly distributed in the central plain and coastal area of the NCP, and characterized by the Na-HCO3 or Na-Cl type water, lower Ca and higher TDS concentrations. Along groundwater flow-path from the mountainous to coastal areas, several hydrogeochemical processes control the mobilization and enrichment of fluoride in groundwater, including cation exchange between Ca and Na on the surface of clay minerals, precipitation/dissolution of carbonates, dissolution of fluorite, marine transgressions, and release of pore water trapped in clayey sediments caused by land subsidence. The fluoride concentrations in the pore water compacted from the sediments ranged from 2.92 to 4.48 mg/L. At the central plain and coastal area, the wide occurrence of land subsidence resulted from the groundwater over-exploration leads to the release of pore water rich in fluoride into surrounding aquifers, thereby elevating the concentration of groundwater fluoride. The resulted groundwater environment with high salinity and some newly-introduced ions, such as Mg, promote the dissolution of fluorite, which was under-saturated in the groundwater samples from the NCP, further enhancing the fluoride enrichment in the groundwater at the coastal area. The findings of this study will provide new insights on the generation of high fluoride groundwater.

Arsenic (As)-contaminated groundwater is a global concern with potential detrimental effects on the health of hundreds of millions of people worldwide. However, the extent of this problem may be more severe than anticipated, as many wells have not been tested and may contain unsafe-level of As. An optimized statistical regression model was developed to predict the probability of geogenic high As groundwater (As > 10 μg/L) in this study. Easily obtained hydrogeochemical and geological parameters that are significantly related to As geochemical behaviors were selected as explanatory variables in the model. The results indicate that pH, Cl−, HCO3−, SO42−, and NO3− concentrations, stratigraphic information, and well depth are excellent predictors of As exposure in the Datong Basin, China. Predicted unsafe wells correspond well with the known distribution of high As groundwater in the Datong Basin. The successful application of a data set from Bangladesh also demonstrated the applicability and credibility of this proposed method.

To understand the characteristics of Ca isotope composition and fractionation in silicate-dominated Quaternary aquifer system, hydrochemical and isotope studies (87Sr/86Sr, 13CDIC and 44/40Ca) were conducted on groundwater, sediment and rock samples from the Datong basin, China. Along the groundwater flow path from the basin margin to the center, groundwater hydrochemical type evolves from Ca-HCO3 to Na-HCO3/Na-Cl type, which results from aluminosilicate hydrolysis, vertical mixing, cation exchange between CaX2 and NaX, and calcite/dolomite precipitation. These processes cause the decrease in groundwater Ca concentration and the associated modest fractionation of groundwater Ca isotopes along the flowpath. The groundwater δ44/40Ca value varies from −0.11 to 0.49‰. The elevated δ44/40Ca ratios in shallow groundwater are attributed to vertical mixing involving addition of irrigation water, which had the average δ44/40Ca ratio of 0.595‰. Chemical weathering of silicate minerals and carbonate generates depleted δ44/40Ca signatures in groundwater from Heng Mountain (east area) and Huanghua Uplift (west area), respectively. Along the groundwater flow path from Heng Mountain to central area of east area, cation exchange between CaX2 and NaX on clay mineral results in the enrichment of heavier Ca isotope in groundwater. All groundwater samples are oversaturated with respect to calcite and dolomite. The groundwater environment rich in organic matter promotes the precipitation of carbonate minerals via the biodegradation of organic carbon, thereby further promoting the elevation of groundwater δ44/40Ca ratios.

A prompt growth in research on arsenic occurrence and behavior in the environment has occurred over the last decade or so. High arsenic (As) in groundwater has become a major global concern due to its widespread occurrence. A comparative hydrogeochemical study was performed on the occurrence of high As groundwater in Datong Basin, China, and Kushtia District, Bangladesh. A total of 132 groundwater samples (83 from Datong Basin and 49 from Kushtia District) were collected to analyze the major hydrogeochemical components and trace elements in groundwater of both areas. Factor analysis (FA) was applied on the hydrochemical data to identify the major hydrogeochemical processes in sedimentary aquifers. High As groundwater was observed in the low-lying central parts of Datong Basin, which are composed of the Holocene alluvial and lacustrine aquifers. The elevated As concentrations ranged from 0.31 to 452 μg/L and distributed in depths between 20 and 45 m. As-enriched groundwater is mainly Na-HCO3 type water and characterized by higher pH value, high Na+, low Ca2+, SO42−, and NO3− along with moderate TDS. The alkaline and reducing subsurface environment facilitate the leaching of As in sedimentary aquifers. The release and distribution of As in aquifers are resulted from the reduction of As-carrying crystalline iron (Fe) oxide/hydroxides and oxidation of organic matter. The aquifers of Kushtia District, Bangladesh, are unconsolidated, alluvial in nature, and developed from Holocene floodplain and Pleistocene deposits. High As (6.04–590.7 μg/L) groundwater occurs mainly in shallow aquifers. The Ca-HCO3 type groundwater is distinguished by circum-neutral pH, medium-high EC, high HCO3−, and low content of NO3−, SO42−, K+, and Cl−. The reductive suspension of MnOOH increases the dissolved As loads and redox responsive elements such as SO42− and pyrite oxidation act as the main mechanisms for As release in groundwater. As is mobilized by anaerobic leakage from the brown-clay and gray-sand into the sediment. Infiltration from irrigation return and surface wash water are the potential factors that remobilize As. The weak loading of Fe suggests that the release of Fe and As is decoupled in sedimentary aquifers of Kushtia District.

The reaction of dipotassio-tetrasilan-1,4-diide (4) with anhydrous SnCl2 at low temperature results in the formation of a five-membered cyclic potassio chlorostannate(II) ([(18-C-6)K](1)). By careful cation exchange reactions, it was transformed into the sodium chlorostannylenoid 2 (by using Na2 [B12 Cl12 ]) or into the non-stabilized cyclic bissilylstannylene 3 (through applying Li[Al(OC(CF3 )3 )4 ]). The increasing Lewis basicity of the bissilylstannylene 3 was analyzed by combined methods of DFT calculations and NMR spectroscopy and substantiated by the synthesis of the corresponding iron carbonyl complexes 7 and 8 from the chlorostannate 1 and the stannylene 3, respectively.

Arsenic (As) contamination of groundwater in Bangladesh is a serious natural calamity and public health hazard. High As concentrations in groundwater (>10 μg l−1) generally occur in Holocene alluvial aquifers. In this study, hydrochemical characteristics and factors influencing As distribution and release were investigated in Prayagpur, Southwestern Bangladesh. Fifty groundwater samples from the tubewells to depths from 21 m to 81 m were collected for hydrochemical and isotopic analysis. The results showed that As concentration in groundwater varied from 6.05 to 590.7 μg l−1 (average 58.31 μg l−1), and about 82% samples contained As exceeding 10 μg l−1. Elevated As concentration mostly occurred in shallow aquifers, which was associated with reducing conditions. High As groundwater was distinguished with weak alkaline pH value, moderate HCO3− and total dissolve solid (TDS), and low NO3− and SO42- concentrations. The groundwater was dominated by Ca·Mg-HCO3 type water that was different from other high As aquifers distributed in the arid area. Moderate alkalinity and the reductive condition, resulted from biochemical reactions were the key controlling factors of As mobilization in aquifers. Environmental isotopes (δ18O and δ2H) confirmed that evaporation did not play a vital role in the process of As enrichment in the groundwater.

The geochemical behaviors of colloids in aquifers played an important role in determining the fate of iodine in groundwater system. To decipher the impact of colloids on iodine mobilization in aquifers, three successive pore-sized colloids filtration (0.45 μm, 30 kDa and 5 kDa) were conducted on in-situ during groundwater sampling. The results showed that the distribution ratios ( f ) of total iodine (I T ) and iron in the dissolved solution (i.e., 5 kDa ultrafiltered) were from 0.78 to 0.99 and from 0.56 to 0.94, respectively. Natural organic matter (NOM) in the colloidal fractions obtained the f values ranging from 0.14 to 1.00. The decreased Eh values from recharge area to discharge area indicated redox potential of groundwater system changed from oxidizing to reducing along groundwater flowpath, and interestingly, the corresponding iodine fractions in groundwater were decreasing in dissolved solution and increasing in colloidal fractions. Inverse correlation between Fe and DOC and positive correlation between iodine and DOC suggested the occurrence of reductive dissolution of iron oxyhydroxides and degradation of organic iodine in groundwater system. Iodine distribution increased in dissolved solution and decreased in colloids with pH increase. Moreover, as pH increased, f (Fe) and f (DOC) decreased in dissolved solution and increased in colloids. Relatively weak correlation of f (I T ) with f (Fe) and strong relationship between f (I T ) and f (DOC) in the large grain size fractions suggested the Fe-OM complexes controlled iodine distribution in groundwater, which depends on the presence of Fe bridges. Negligible association of iodine with Fe and NOM in the small grain size fractions might be attributed to the effects of abundant OH − content in groundwater.

To better understand the enrichment of fluoride and iodine in groundwater at North China Plain (NCP), speciation analysis and geochemical modeling were conducted to identify the key hydrochemical processes controlling their mobilization in groundwater system. Groundwater fluoride and iodine concentrations ranged from 0.18 to 5.59mg/L and from 1.51 to 1106μg/L, respectively, and approximately 63% and 32.3% of groundwater fluoride and iodine were higher than the guidelines for drinking water (1.5mg/L and 150μg/L). High fluoride concentration (>1.5mg/L) can be detected in groundwater from the flow-through and discharge areas of NCP, and high iodine groundwater (>150μg/L) is mainly scattered in the coastal area. Na-HCO3/Cl type water resulted from water-rock interaction and seawater intrusion favors fluoride and iodine enrichment in groundwater. Speciation analysis results indicate that (1) fluoride complexes in groundwater are dominated by free fluoride, the negative charge of which favors fluoride enrichment in groundwater under basic conditions, and (2) iodide, iodate and organic iodine co-occur in groundwater at NCP with iodide as the dominant species. The geochemical modeling results indicate that groundwater fluoride is mainly associated with the saturation states of fluorite and calcite, as well as the adsorption equilibrium onto goethite and gibbsite, including the competitive adsorption between fluoride and carbonate. Groundwater iodine is mainly controlled by redox potential and pH condition of groundwater system. Reducing condition favors the mobilization and enrichment of groundwater iodide, which has the highest mobility among iodine species. Under reducing condition, reductive dissolution of iron (oxy)hydroxides is a potential geochemical process responsible for iodine release from sediment into groundwater. Under (sub)oxidizing condition, as groundwater pH over the 'point of zero charge' of iron (oxy)hydroxides, the lowering adsorption capacity of groundwater iodide/iodate on minerals leads to the release of sediment iodine into groundwater.

Groundwater fluoride is posing a health risk to humans, and analyzing groundwater quality is time-wasting and expensive. Statistical methods provide a valuable approach to study the spatial distribution of groundwater fluoride. Random Forest (RF), Artificial Neural Network (ANN), and Logistic Regression (LR) were used in this study for groundwater fluoride prediction in Datong Basin. The groundwater chemistry of 482 groundwater samples was collected and used to figure out the performance of three statistical technologies and extract the main factors controlling the enrichment of fluoride in groundwater. The data was separated into two parts for the statistical analysis, 80% for training and 20% for testing. The Chi-squared was applied to select the most relevant variables, and TDS, Cl−, NO3−, Na+, HCO3−, SO42−, K+, Zn, Ca2+, and Mg2+ were selected as best inputs for the fluoride prediction. Models were evaluated using the confusion matrix and The receiver operating characteristic area under the curve ROC (AUC). The results suggest that within ten input variables, the accuracies of RF, ANN, and LR were 0.89, 0.85, and 0.76, respectively. The mean decrease in impurity (MDI) and permutation feature demonstrates that eight of ten parameters, including TDS, Cl−, NO3−, Na+, HCO3−, SO42−, Ca2+ and Mg2+ are the variables influencing the groundwater fluoride in the study area. RF exhibited the best model with high conformity and confidence in predicting groundwater fluoride contamination in the study area.

This paper reports the potential use of municipal solid waste incineration fly ash (IFA) as cement supplement for the production of strain hardening cementitious composites (SHCC). Results showed that IFA is not a conventional pozzolan according to ASTM C618 . Certain chemical reaction; however, occurred when IFA is used together with cement as evidenced by the formation of Friedel’s salt in IFA-SHCCs. As a result, the compressive strength as well as tensile ductility of IFA-SHCCs can be maintained when up to 20% cement was replaced by IFA. At higher replacement level, however, excessive alkali metal chloride may leach out from the matrix leading to porous honeycomb microstructure of matrix which results in reduced compressive strength but enhanced tensile ductility of IFA-SHCCs. Leaching tests showed that almost all heavy metals concentration complied with the limits set in the Dutch Soil Quality Decree for construction materials. This suggests SHCC binder can effectively immobilize heavy metals in IFA potentially due to the low water-to-binder ratio of IFA-SHCCs matrix. Preliminary evaluation indicates that IFA may be used to replace cement in the production of SHCC. Further studies are necessary to investigate the long-term environmental impact of IFA-SHCCs.

A novel idea of using carbon nanofibers (CNFs) to strengthen the interface transition zone (ITZ) and to enhance the interface frictional bond strength between polyethylene (PE) fibers and cement-based matrix was proposed and realized by coating CNFs on surface of PE fibers through hydrophobic interactions. A strain hardening ultra-high performance concrete (SHUHPC) incorporating such CNF-coated PE fibers was developed. The resulting CNF-SHUHPC has a compressive strength over 150 MPa and exhibits 15% enhancement in tensile strength, 20% improvement in tensile strain capacity, and reduced cracking spacing. Single fiber pullout tests showed the interface frictional bond strength of the CNF-coated PE fiber was increased by 22%, which is attributed to CNFs strengthening the ITZ by filling nano-pores and bridging nano-cracks resulting in denser microstructure and higher crack resistance against fiber pullout as revealed by the micrographs. The increased interface frictional bond strength leads to higher tensile strength and increased tensile strain capacity as predicted by the micromechanical model.

Characterizing the properties of main host of iodine in soil/sediment and the geochemical behaviors of iodine species are critical to understand the mechanisms of iodine mobilization in groundwater systems. Four surface soil and six subsurface sediment samples were collected from the iodine-affected area of Datong basin in northern China to conduct batch experiments and to evaluate the effects of NOM and/or organic-mineral complexes on iodide/iodate geochemical behaviors. The results showed that both iodine contents and kf-iodate values had positive correlations with solid TOC contents, implying the potential host of NOM for iodine in soil/sediment samples. The results of chemical removal of easily extracted NOM indicated that the NOM of surface soils is mainly composed of surface embedded organic matter, while sediment NOM mainly occurs in the form of organic-mineral complexes. After the removal of surface sorbed NOM, the decrease in kf-iodate value of treated surface soils indicates that surface sorbed NOM enhances iodate adsorption onto surface soil. By contrast, kf-iodate value increases in several H2O2-treated sediment samples, which was considered to result from exposed rod-like minerals rich in Fe/Al oxyhydroxide/oxides. After chemical removal of organic-mineral complexes, the lowest kf-iodate value for both treated surface soils and sediments suggests the dominant role of organic-mineral complexes on controlling the iodate geochemical behavior. In comparison with iodate, iodide exhibited lower affinities on all (un)treated soil/sediment samples. The understanding of different geochemical behaviors of iodine species helps to explain the occurrence of high iodine groundwater with iodate and iodide as the main species in shallow (oxidizing conditions) and deep (reducing conditions) groundwater.

Ti/Cu/N coatings with different Cu contents were deposited on titanium alloy surface by the DC magnetron sputtering technique. XPS and FESEM were employed to characterize the composition and structure of the coating on the Ti6Al4V substrates. In addition, The adhesion force, friction, and wear properties of the Ti/Cu/N coatings were investigated. The experimental results showed that the coarse particles of the coatings would grow more and the surface roughness increased with the increase of copper content in the coatings; The coatings showed a strong adhesion force; The friction coefficient of the coating of the samples was less than the substrate, reaching 0.19 at least. The wear resistance of the coatings could be improved by optimizing and controlling the relative content of Ti, Cu, N elements on the titanium alloy surface, especially the 10.98 at% contents of the copper. The sample C2 kept the best wear resistance.

In order to reveal the pattern of spatial distribution of iodine in groundwater at North China Plain (NCP), a total of 136 groundwater samples were collected along the regional groundwater flow paths. The results showed that groundwater iodine ranged from 1.51 to 1106μg/L, and 31.4% of the samples have iodine concentrations higher than 150μg/L. High iodine groundwater samples are mainly observed in the coastal area of Bohai sea, and well depths greater than 350 m. The results of iodine speciation analysis showed that groundwater iodide, iodate and organic iodine had the ranges of

In order to identify the effects of groundwater colloids on iodine mobilization in aquifer system, nine groundwater samples were in-situ filtered through successive pore-sized membranes (0.45 μm, 30 kDa and 5 kDa) using filtration technique under N 2 atmosphere. Obvious decrease in groundwater iodine, Fe, Al and DOC was observed in the larger pore-sized fractions, indicating that groundwater iodine is closely associated with larger Fe-Al colloids. The analysis result of sample DT15-27 suggests that the extremely reducing condition could promote iodine dissolved in the truly dissolved phase. For low iodine groundwater, no good correlation between iodine and Fe, Al, DOC was observed for all sequential filtration steps, suggesting that groundwater iodine is trapped in the truly dissolved phase because of competitive adsorption of iron/aluminum.

Almost 20 years’ multi-disciplinary study on geogenic high arsenic (As) groundwater systems in China has greatly improved our understanding of the major processes controlling hydrogeochemical behavior of As in the subsurface environment. Among them, sorption by Fe(III) oxide/hydroxides was found to be one of the dominant processes retaining As in the aquifer matrix. Managed Aquifer Rehabilitation (MAR) by enhancing Fe(II) oxidation to promote As sorption was proposed and tested in a pilot-scale field experiment. Periodical injection of Fe(II) and ClO − into a high As sandy aquifer triggered formation of new Fe(III) (hydr)oxides coating on sediment particles via advanced heterogeneous oxidation of Fe(II) and concurrent oxidative adsorption of As(III) via co-precipitation and surface complexation with Fe(III) (hydr)oxides. Monitoring results indicate that aqueous As concentration decreased from the initial average value of 78.0 μg/L to 9.8 μg/L over the 25-day amendment period and leveled off below 10 μg/L for the following 30 days. MAR is thus proved to be a cost-effective approach for remediating high As aquifers.

High iodine concentrations in groundwater have caused serious health problems to the local residents in the Datong basin, northern China. To determine the impact of water-sediment interaction and irrigation practices on iodine mobilization in aquifers, isotope ( 2 H, 18 O and 87 Sr/ 86 Sr) and hydrogeochemical studies were conducted. The results show that groundwater iodine concentrations vary from 14.4 to 2180 μg/L, and high iodine groundwater (>150 μg/L) mainly occurs in the central area of the Datong basin. Sediment iodine content is between 87 Sr/ 86 Sr values and groundwater chemistry suggest that aluminosilicate hydrolysis is the dominant process controlling hydrochemical evolution along groundwater flowpath, and the degradation of TOC/iodine-rich sediment mediated by microbes potentially triggers the iodine release from the sediment into groundwater in the discharge area. The vertical stratification of groundwater 18 O and 2 H isotope reflects the occurrence of a vertical mixing process driven by periodic surface irrigation. The vertical mixing could change the redox potential of shallow groundwater from sub-reducing to oxidizing condition, thereby affecting the iodine mobilization in shallow groundwater. It is postulated that the extra introduction of organic matter and O 2 /NO 3 /SO 4 could accelerate the microbial activity due to the supplement of high ranking electron acceptors and promote the iodine release from the sediment into shallow groundwater.

With the widespread use of pesticides, the resistance to pesticides of pests has gradually increased, caused mixed pesticides to become even more widely used for practical applications. To investigate the effects of mixed pesticides on reproductive health in an occupational greenhouse environment, the greenhouse environment and the characteristics of the actual application were constructed, and then the male mice were comprehensively exposed to a mixture of the beta-cypermethrin and emamectin benzoate environmental. Additionally, the effect of the beta-cypermethrin and emamectin benzoate mixture on the reproductive health of male mice was known. The results showed that with the prolongation of exposure duration, the activities of Glutathione Peroxidase (GSH-Px), Total Superoxide Dismutase (T-SOD), Lactate dehydrogenase (LDH) and Acid phosphatase (ACP) in the testes of mice gradually decreased and the activity of Malondialdehyde (MDA) gradually increased. It was also found that the apoptosis rate of murine testicular cells increased and that DNA damage occurred with prolonged exposure duration. Therefore, it can be inferred that exposure to a mixture of the pesticides beta-cypermethrin and emamectin benzoate in the greenhouse environment may have adverse effects on the reproductive health of male mice.

The purpose of this paper is to observe the protective action and its effective mechanism of eriodictyol on lipopolysaccharide (LPS)-induced acute lung injury (ALI). In this study, our results indicated that eriodictyol could dramatically suppress the inflammatory mediators, including interleukin-6 (IL-6), IL-1β, prostaglandin E2, and tumor necrosis factor-α in bronchoalveolar lavage fluid of LPS-challenged mice. Eriodictyol also alleviated the wet/dry ratio and improved pathological changes of the lung. In addition, eriodictyol significantly decreased myeloperoxidase activity and malondialdehyde content as well as increased superoxide dismutase activity. Moreover, eriodictyol inhibited the COX-2/NLRP3/NF-κB signaling pathway in the lung tissues of ALI mice. In conclusion, our observations validated that eriodictyol processed the protective effects on ALI mice, which was related to the regulation of the COX-2/NLRP3/NF-κB signaling pathway.

Groundwater iodine has direct importance for human dietary iodine intake in areas where drinking water is of groundwater origin. However, little is known about enrichment and mobilization mechanisms of groundwater iodine in the North China Plain (NCP). Geochemistry, inorganic/organic carbon isotope and biomarker of groundwater and sediment samples were studied to reveal the effects of depositional environment and organic matter (OM) degradation on the generation of high iodine groundwater (>100 μg/L) in NCP. Results showed that groundwater iodine had a range of 7.2–800 μg/L and was increasing with increase in HCO3 concentration and decrease in groundwater δ13CDIC value, indicating the potential effects of microbial activity on the elevation of groundwater iodine. Sediments iodine ranged from 0.03 to 2.54 μg/g and higher contents occurred under the oxidizing depositional environment (higher Pr/Ph ratios). Biomarker analysis indicated that the marine iodine-rich OM is considered as the main source of groundwater iodine, which is prone to be released into groundwater by the microbial degradation under the reducing conditions. The hypothesis was evidenced by the 13Corg, 13CDIC and 3-D excitation emission matrices of groundwater. These results suggest that carbon-related biogeochemical cycling and redox condition are important in the enrichment and mobilization of iodine in groundwater system.

It is well known that exercise-induced fatigue is exacerbated following hypoxia exposure and may arise from central and/or peripheral mechanisms. To assess the relative contribution of peripheral and central factors to exercise-induced fatigue under hypoxia, a rat model of fatigue by a bout of exhaustive swimming was established and fatigue-related biochemical changes in normoxic and severe hypoxic conditions were compared. Rats were randomly divided into four groups, normoxia resting (NR), exhaustive swimming (NE), hypoxia resting (HR) and exhaustive swimming (HE) groups. The swimming time to exhaustion with a weight equal to 2.5% of their body weight reduced under hypoxia (HE 37±9 min vs. NE 91±16 min, p

The synthesis of a series of 1,2-diamino-o-carboranes (1-4) is reported. The molecular structures of these diamino-o-carboranes are remarkable as the inner-cluster C-C bonds are all ultra-long (162.7-193.1 pm) and vary substantially with small variations in the substituents. The results of quantum mechanical investigations suggest that the origin of the bond elongation is significant in-plane negative hyperconjugation of lone pairs of the nitrogen substituents with the σ* orbitals of the C-C bonds in o-carboranes.

Cadmium (Cd) calcite coprecipitation experiments were conducted to constrain the possible Cd isotope fractionation mechanism under different conditions. The changes in Cd/Ca molar ratio, HCO3− concentration, addition of Mg2+, Na2EDTA, or ionic strength (INaNO3) did not affect the composition of the precipitation but resulted in substantial change in mineral morphology. Cd exhibited an apparent isotope fractionation in the process of coprecipitation with calcite, and the fractional coefficient αCaCO3-Cd(aq) was less than one, indicating that the solution is preferentially enriched in heavy isotopes. The Cd mainly existed in the form of Cd(H2O)62+ in the solution before the reaction and was dominated by Cd(NO3)2, CdNO3+, Cd(EDTA)2− at the end of the experiments. The different isotopic ratios of Cd between the liquid phase and the solid phase can be explained by changes in Cd speciation which have different bond lengths of Cd O. Expect for the experiments with Na2EDTA and high ionic strength, the measured isotope ratios under different conditions plotted around the theoretical Rayleigh fractionation curve. This demonstrates that Cd isotopes almost reach equilibrium with Cd-calcite coprecipitation under the different experiment conditions and the Cd isotope fractionation mechanism is closely related to the thermodynamic isotope fractionation. In the experiment with Na2EDTA and high ionic strength, the formation of Cd(EDTA)2− and ion occlusion at surface sites inhibit Cd2+ entering the calcite and the isotopes of the solid and liquid phases do not reach equilibrium. As the result, obtained experiment data shift from the Rayleigh fractionation curve indicating the Cd isotope fractionation mechanism is closely related to the kinetic isotope effect. In general, the study results indicate that the Cd/Ca molar ratio, ionic strength, HCO3−, Na2EDTA, and Mg2+ concentrations of the solution can cause Cd isotope fractionation in different degrees during Cd-calcite coprecipitation. Cd isotope ratios might potentially provide important information on Cd mobilization and transportation in groundwater environment.

The phospholipid fatty acids (PLFA) and dissolved organic matter (DOM) 3D fluorescent signatures were appointed to elaborate arsenic (As) mobilization mechanism in groundwater from the Datong Basin. Groundwater samples were collected along the groundwater flow path from recharge zones to discharge zones according to redox sensitive parameters. Variations of Eh, NO3− and SO42− manifested the redox condition shifted from a weakly oxidative environment to highly reductive environment. In recharge zones, some aerobic bacteria may serve as the dominant species, such as Thiothrix (S-oxidizing bacteria: SOB), Gallionella (Fe-oxidizing bacteria: FeOB) and Fluviicola, characterized by 16:1ω7, 16:0 and 18:1ω7 PLFAs. The biogeochemical processes were mainly governed by aerobic bacteria exploiting protein-like DOM as electron donors to maintain metabolism together with depleting of O2 and NO3− (electron acceptors), which restricted the reduction of As. While in discharge zones, the anaerobic microbes played a predominant role, such as Desulfosporosinus (Sulfate reducing bacteria: SRB) and Clostridia (Fe reducing bacteria: FeRB), indicated by cy17:0, cy19:0 and 18:1ω9 PLFAs. SRB and FeRB mainly utilized protein-like DOM as energy sources for respiratory action. Simultaneously, biogenic reductive dissolution of Fe(III) (hydr)oxides and reduction of As(V), SO42− resulted in geogenic immobilized As reductive desorption into aquifers. The positive linear correlations between humic substances and Fe, As suggested that As-Fe-DOM complexation can enhance the transport of As and Fe in aqueous environments. The negative relationships between SRB/FeRB and As/Fe concentrations demonstrated that the HS− could react with Fe(II) and As(III) to form secondary Fe(II) sulfides or As-bearing sulfides, which subsequently sequestered As from groundwater via sorption or coprecipitation. In conclusion, the utilization of biodegradable protein-like DOM by SRB/FeRB being associated with reductive dissolution of As-bearing Fe (hydr)oxides minerals and As-Fe-DOM complexation promoted As mobility in groundwater aquifers.

Understanding the formation of thioarsenate, an important arsenic species, is of great significance with respect to explaining the mobilization of arsenic in fresh groundwater systems. Monothioarsenate (MTA), dithioarsenate (DTA), and trithioarsenate (TriTA) are three main forms of thioarsenate in fresh groundwater. A total of 30 groundwater samples were collected from the Datong basin to conduct hydrochemistry and arsenic speciation analysis. Geochemical simulations were established to verify the occurrence of thioarsenate. The results show thioarsenate was detected in 40% of the groundwater samples at concentrations ranging from 2.36 to 209.9 μg/L; the highest concentration accounted for 68% of total arsenic. Thioarsenate mainly occurs in the discharge area of the Datong basin, where the groundwater was characterized by strongly reducing conditions (Eh up to −175.3 mV) and higher concentrations of arsenic (up to 3450 μg/L) and sulfide (up to 8480 μg/L). A strong positive correlation (r = 0.81, p

Long-term intake of groundwater with elevated iodine concentration can cause thyroid dysfunction in humans; however, little is known on the mechanisms controlling the fate of iodine in groundwater systems. In this study, the groundwater and aquifer sediment samples from the Datong basin, a geologic iodine-affected area, were collected to perform the batch incubation experiments to understand the release and enrichment of iodine in groundwater systems. The results showed that the groundwater from the deep confined aquifer had a total iodine concentration of 473 μg/L, higher than that of shallow groundwater, and iodide is the dominant species of iodine. The deep confined aquifer was characterized by the reducing conditions. Meanwhile, a higher ratio of Fe(II) to total Fe was observed in bulk deep aquifer sediments (59%) in comparison with that of shallow sediments (33%). The results of batch incubation experiments showed that during the reductive transformation of Fe minerals in shallow aquifer sediments, iodide concentration in solution was gradually increasing from 24.7 to 101.5 μg/L after 10 days. It suggests that the transformation of Fe minerals in aquifer sediments acts as a diver causing the release of iodine from sediment into groundwater, which was further supported by the features Fe K-edge EXAFS before and after the batch experiments. Moreover, the changes in iodine species from iodate or organic iodine into iodide during the release further promotes the release of sediment iodine, which was supported by the developed geochemical models. The prevalence of reducing condition in deep aquifer favors the enrichment of released iodide. This study provides new insights into the mechanisms of iodide enrichment observed in deep confined aquifer.

The paper studies tribological properties of some new Ti/Cu/N films. These Ti/Cu/N films prepared by three different diameter coppers were embedded in the titanium target, and then were deposited on Ti alloy surface by DC magnetron sputtering. After that, the microstructure, thickness, adhesion and friction/wear properties of the film are characterized and analyzed. The results show that the composite film mainly made up of Ti/Cu and Ti/Cu/N have well adhesion and wear properties. Especially, the film prepared by a diameter of 3 mm thin-film copper inlaid titanium target sputter deposition have good performance on friction and wear.

Summary An in situ Fe-sulfide coating approach has been developed for As-contaminated groundwater remediation. Alternate injection of Fe(II), O2-free water and S2− can realize Fe-sulfide coating onto quartz sands with minor changes in porosity. As(III) uptake experiment indicated that the retardation factor for As(III) was 37 and dynamic retention capacity was 44.94 mg As(III)/g Fe, which was much higher than the maximum adsorption capacity for As(III) by FeS and FeS2. This result indicated that adsorption cannot be the only mechanism for As(III) uptake by Fe-sulfide coating layer. The SEM image and FTIR spectra results suggested that interaction between As(III) and Fe-sulfides and formation of As-sulfide precipitates could significantly contribute to As(III) uptake by Fe-sulfide coating layer. Alternate injection of Fe(II) + As(III) and S2− was conducted to simulate in situ As immobilization from real groundwater. The SEM image showed that the quartz sands were mainly covered by crystalline framboidal pyrite after such amendment. The breakthrough of As(III) was not observed during this experiment and the removal capacity for As(III) was 109.7 mg As/g Fe. The As(III) immobilization mechanism during alternate injection of Fe(II) + As(III) and S2− was significantly different from that of As(III) uptake by Fe-sulfide coating. The direct interaction between As(III) and S2− produced As-sulfides contributed to the high As(III) removal capacity during alternate injection of Fe(II) + As(III) and S2−. This result indicated that alternate injection of Fe(II) and S2− approach has an attractive application for As-contaminated groundwater remediation under strongly reducing environment.