Immobilisation remediation of arsenic-contaminated soils with promising CaAl-layered double hydroxide and bioavailability, bioaccessibility, and speciation-based health risk assessment.

Arsenic (As)-contaminated soil poses great health risk to human mostly through inadvertent oral exposure. We investigated CaAl-layered double hydroxide (CaAl-LDH), a promising immobilising agent, for the remediation of As-contaminated Chinese soils. The effects on specific soil properties and As fractionation were analyzed, and changes in the health risk of soil As were accurately assessed by means of advanced in vivo mice model and in vitro PBET-SHIME model. Results showed that the application of CaAl-LDH significantly increased soil pH and concentration of Fe and Al oxides, and effectively converted active As fractions into the most stable residual fraction, guaranteeing long-term remediation stability. Based on in vivo test, As relative bioavailability was significantly reduced by 37.75%. Based on in vitro test, As bioaccessibility in small intestinal and colon phases was significantly reduced by 25.65% and 28.57%, respectively. Furthermore, As metabolism (reduction and methylation) by the gut microbiota inhabiting colon was clearly observed. After immobilisation with CaAl-LDH, the concentration of bioaccessible As(Ⅴ) in the colon fluid was significantly reduced by 61.91%, and organic As (least toxic MMA(V) and DMA(V)) became the main species, which further reduced the health risk of soil As. In summary, CaAl-LDH proved to be a feasible option for immobilisation remediation of As-contaminated soils, and considerable progress was made in relevant health risk assessment.

Influences of coexisting aged polystyrene microplastics on the ecological and health risks of cadmium in soils: A leachability and oral bioaccessibility based study.

Whether coexisting microplastics (MPs) affect the ecological and health risks of cadmium (Cd) in soils is a cutting-edge scientific issue. In this study, four typical Chinese soils were prepared as artificially Cd-contaminated soils with/without aged polystyrene (PS). TCLP and in vitro PBET model were used to determine the leachability (ecological risk) and oral bioaccessibility (human health risk) of soil Cd. The mechanisms by which MPs influence soil Cd were discussed from direct and indirect perspectives. Results showed that there was no significant difference in the leachability of soil Cd with/without aged PS. Additionally, aged PS led to a significant decrease in the bioaccessibility of soil Cd in gastric phase, but not in small intestinal phase. The increase in surface roughness and the new characteristic peaks (e.g., Si-O-Si) of aged PS directly accounted for the change in Cd bioaccessibility. The change in organic matter content indirectly accounted for the exceptional increase in Cd bioaccessibility of black soil with aged PS in small intestinal phase. Furthermore, the changes in cation exchange capacity and Cd mobility factor caused by aged PS explained the change in Cd leachability. These results contribute to a deeper understanding about environmental and public health in complicated emerging scenarios.

Comparative Analyses of EPA-Phosphatidylcholine, EPA-Lysophosphatidylcholine, and DHA-Lysophosphatidylcholine on DHA and EPA Repletion in n-3 PUFA-Deficient Mice.

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) play an important role in maintaining the physiological functions of tissues, and the beneficial effects of DHA/EPA in phospholipid forms have been widely reported. Although lysophosphatidylcholine (LPC) is considered to be the preferred form of DHA supplementation for the brain, the kinetics of DHA and EPA recovery and corresponding changes of n-6 docosapentaenoic acid (DPA) and arachidonic acid (AA) levels in different phospholipid molecules and different tissues after administration of EPA in phosphatidylcholine (PC) and LPC forms and DHA in the LPC form are not clear. Here, we measured the total fatty acids in tissues and fatty acid composition of different phospholipid molecules after gavage administration of equal molar amounts of EPA/DHA in mice with n-3 polyunsaturated fatty acid (PUFA) deficiency induced by maternal dietary deprivation of n-3 PUFA during pregnancy and lactation. The results showed that dietary supplementation with EPA-PC, EPA-LPC, and DHA-LPC exhibited different priorities for EPA or DHA accretion and supplementation efficiency curves in different tissues during the developing period. EPA-PC exhibited a more optimal efficacy in DHA and EPA repletion in serum and hepatic total fatty acids. In terms of DHA recovery in the brain, EPA-LPC and DHA-LPC showed great effects. Meanwhile, the DHA level in total fatty acids and major fractions of phospholipids (PC, PE, and PI + PS) in the heart and bone marrow with the supplementation of DHA-LPC displayed a relatively considerable increase compared with that of EPA supplementation groups. The study provides a reference for the time course of DHA or EPA recovery in phospholipid molecular species in different tissues after the supplementation of EPA-PC, EPA-LPC, and DHA-LPC.

Enhanced laccase production by mutagenized Myrothecium verrucaria using corn stover as a carbon source and its potential in the degradation of 2-chlorophen.

Chlorophenols are widely used in industry and are known environmental pollutants. The degradation of chlorophenols is important for environmental remediation. In this study, we evaluated the biodegradation of 2-chlorophenol using crude laccase produced by Myrothecium verrucaria. Atmospheric and room temperature plasma technology was used to increase laccase production. The culture conditions of the M-6 mutant were optimized. Our results showed that corn stover could replace glucose as a carbon source and promote laccase production. The maximum laccase activity of 30.08 U/mL was achieved after optimization, which was a 19.04-fold increase. The biodegradation rate of 2-chlorophenol using crude laccase was 97.13%, a positive correlation was determined between laccase activity and degradation rate. The toxicity of 2-CP was substantially reduced after degradation by laccase solution. Our findings show the feasibility of the use of corn stover in laccase production by M. verrucaria mutant and the subsequent biodegradation of 2-chlorophenol using crude laccase.

GmCIPK21, a CBL-interacting protein kinase confers salt tolerance in soybean (Glycine max. L).

Salt stress severely affects plant development and yield. Calcineurin B-like protein interacting protein kinases (CIPKs) play a crucial role in plant adaptation to environmental challenges. However, the biological functions of CIPKs in soybean remain poorly understood. Here, we identified GmCIPK21, a salt-responsive CIPK gene from soybean. Overexpression of GmCIPK21 in Arabidopsis and soybean hairy roots led to increased salt tolerance. The hairy roots with GmCIPK21 suppression by RNA interference exhibited salt-sensitive phenotypes. Further physiological analysis revealed that GmCIPK21 reduced the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) and increased the activity of the antioxidant enzymes under salt stress. Additionally, GmCIPK21 was found to enhance the ABA sensitivity of transgenic plants. GmCIPK21 was also implicated in increasing the activation of antioxidant-, salt-, and ABA-related genes upon salt stress. Interestingly, GmCIPK21 interacted with GmCBL4, promoting the scavenging salt-induced reactive oxygen species (ROS). These results collectively suggested that GmCIPK21 affects ROS homeostasis and ABA response to improve salt tolerance in soybean.

Melatonin mediates reactive oxygen species homeostasis via SlCV to regulate leaf senescence in tomato plants.

Melatonin (MT) functions in removing reactive oxygen species (ROS) and delaying plant senescence, thereby acting as an antioxidant; however, the molecular mechanism underlying the specific action of MT is unclear. Herein, we used the mutant plants carrying the MT decomposition gene melatonin 3-hydroxylase (M3H) in tomato to elucidate the specific mechanism of action of MT. SlM3H-OE accelerated senescence by decreasing the content of endogenous MT in plants. SlM3H is a senescence-related gene that positively regulates aging. MT inhibited the expression of the senescence-related gene SlCV to scavenge ROS, induced stable chloroplast structure, and delayed leaf senescence. Simultaneously, MT weakened the interaction between SlCV and SlPsbO/SlCAT3, reduced ROS production in photosystem II, and promoted ROS elimination. In conclusion, MT regulates ROS homeostasis and delays leaf aging in tomato plants through SlCV expression modulation.

The soybean CBL-interacting protein kinase, GmCIPK2, positively regulates drought tolerance and ABA signaling.

Calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) play important roles in plant environmental stress responses. However, the biological functions of the CBL-CIPK signaling pathway in the tolerance of soybean (Glycine max) to drought stress remain elusive. Here, we characterized the GmCIPK2 gene in soybean, and its expression was induced by drought stress and exogenous abscisic acid (ABA) treatments. The overexpression of GmCIPK2 enhanced drought tolerance in transgenic Arabidopsis and soybean hairy roots, whereas downregulation of GmCIPK2 expression in soybean hairy roots by RNA interference resulted in increased drought sensitivity. Further analysis showed that GmCIPK2 was involved in ABA-mediated stomatal closure in plants under drought stress conditions. GmCIPK2 increased the expression of ABA- and drought-responsive genes during drought stress. Additionally, yeast two-hybrid, pull-down, and bimolecular fluorescence complementation assays demonstrated that a positive regulator of drought stress, GmCBL1, physically interacted with GmCIPK2 on the plasma membrane. Collectively, our results demonstrated that GmCIPK2 positively regulates drought tolerance and ABA signaling in plants, providing new insights into the underlying mechanisms of how the CBL-CIPK signaling pathway contributes to drought tolerance in soybean.

BES/BZR Transcription Factor TaBZR2 Positively Regulates Drought Responses by Activation of TaGST1.

BRI1-EMS suppressor (BES)/brassinazole-resistant (BZR) family transcription factors are involved in a variety of physiological processes, but the biological functions of some BES/BZR transcription factors remain unknown; moreover, it is not clear if any of these proteins function in the regulation of plant stress responses. Here, wheat (Triticum aestivum) brassinazole-resistant 2 (TaBZR2)-overexpressing plants exhibited drought tolerant phenotypes, whereas downregulation of TaBZR2 in wheat by RNA interference resulted in elevated drought sensitivity. electrophoretic mobility shift assay and luciferase reporter analysis illustrate that TaBZR2 directly interacts with the gene promoter to activate the expression of T. aestivum glutathione s-transferase-1 (TaGST1), which functions positively in scavenging drought-induced superoxide anions (O2 -). Moreover, TaBZR2 acts as a positive regulator in brassinosteroid (BR) signaling. Exogenous BR treatment enhanced TaBZR2-mediated O2 - scavenging and antioxidant enzyme gene expression. Taken together, we demonstrate that a BES/BZR family transcription factor, TaBZR2, functions positively in drought responses by activating TaGST1 and mediates the crosstalk between BR and drought signaling pathways. Our results thus provide new insights into the mechanisms underlying how BES/BZR family transcription factors contribute to drought tolerance in wheat.

Wheat CBL-interacting protein kinase 23 positively regulates drought stress and ABA responses.

BACKGROUND: The calcineurin B-like protein (CBL)-interacting protein kinase (CIPK) signaling pathway responds to various abiotic stresses in plants. RESULTS: Wheat CIPK23, isolated from wheat drought transcriptome data set, was induced by multiple abiotic stresses, including drought, salt, and abscisic acid (ABA). Compared with wild-type plants, TaCIPK23-overexpression wheat and Arabidopsis showed an higher survival rate under drought conditions with enhanced germination rate, developed root system, increased accumulation of osmolytes, and reduced water loss rate. Over-expression of TaCIPK23 rendered transgenic plants ABA sensitivity, as evidenced by delayed seed germination and the induction of stomatal closure. Consistent with the ABA-sensitive phenotype, the expression level of drought- and ABA-responsive genes were increased under drought conditions in the transgenic plants. In addition, using yeast two-hybrid system, pull-down and bimolecular fluorescence complementation (BiFc) assays, TaCIPK23 was found to interact with TaCBL1 on the plasma membrane. CONCLUSIONS: These results suggest that TaCIPK23 plays important roles in ABA and drought stress responses, and mediates crosstalk between the ABA signaling pathway and drought stress responses in wheat.

Sequence Analysis and Comparison of the Key Genes of Domestic Live Attenuated Varicella Vaccine.

Objective To analyze the safety and consistency of domestic live attenuated varicella vaccines (LAVVs) at gene level.Methods The key genes (ORF38,ORF54,and ORF62) of LAVVs produced by four Chinese manufacturers were amplified by polymerase chain reaction (PCR) and sequenced.The sequencing results were compared with the sequences of Dumas,P-Oka,and V-Oka strains in GenBank and with the sequences of Varilrix (GSK) and Varivax (Merck).Results The ORF38 and ORF54 gene sequences of four domestic LAVVs were the same as each other and completely consistent with the sequences of V-Oka and Varilrix;however,it was different from Varivax (Merck) at one site.The ORF62 gene sequences of four domestic LAVVs were similar,and had individual nucleotide differences with V-Oka,Varilrix(GSK),and Varivax (Merck).Conclusions The sequences of ORF38,ORF54,and ORF62 of four domestic LAVVs are almost the same,showing good stability.They have small differences with V-Oka,Varilrix(GSK),and Varivax (Merck),without introducing new mutations.

Asymmetric Mannich Reaction of Aryl Methyl Ketones with Cyclic Imines Benzo[e][1,2,3]oxathiazine 2,2-Dioxides Catalyzed by Cinchona Alkaloid-based Primary Amines.

Aryl ketones represent problematic substrates for asymmetric Mannich reactions due to a large steric hindrance exhibited by such compound species. A highly enantioselective direct Mannich reaction of aryl methyl ketones with cyclic imine benzo[e][1,2,3]oxathiazine 2,2-dioxides could be successfully carried out utilizing a combination of cinchona alkaloid-derived primary amines with trifluoroacetic acid (TFA); the primary amines feature a superior catalytic efficacy over secondary amines with a variety of sterically hindered carbonyl compounds as substrates. The reaction proceeded well with various cyclic imines in 89-97 % ee and with various aryl methyl ketones in 85-98 % ee. Moreover, the aryl carbonyl of a Mannich product could be transformed to ketoxime, which further undergoes a Beckmann rearrangement to produce an amide compound while maintaining enantioselectivity.

[Residue Characteristics of Perfluorinated Compounds in the Atmosphere of Shenzhen].

In order to explore the residual characteristics of perfluorinated compounds (PFCs) in the atmosphere of Shenzhen, passive air samplers consisting of polyurethane foam (PUF) disks impregnated with XAD-4 power were deployed at 12 sites in Shenzhen from November 2014 to February 2015. Seven volatile and fifteen ionic PFCs were analyzed. The results indicated that ΣPFCs concentration ranged from 23.7 pg x m(-3) to 157 pg x m(-3) (mean: 79.0 pg x m(-3)), dominated by volatile PFCs, with 8:2 FTOITI, 6:2 FTOH, PFPeA, PFOA being the dominant compounds. The spatial distribution of volatile and ionic PFCs concentrations was the same, displaying the characteristic of "the northwest being higher than the southeast ". Furthermore, the concentrations of 6:2 FTOHs, 8:2 FTOHs, PFPeA, PFHxA and PFOA had positive correlations with PM2.5 and PM10 (P < 0.05, P < 0.01) and were more positively correlated with the levels of PM10 than those of PM2.5.

[Simulation of Multimedia Transfer and Fate of Perfluorooctane Sulfonate (PFOS) in Shenzhen Region].

To study the transfer and fate of perfluorooctane sulfonate (PFOS) in Shenzhen region, a level Ⅲ fugacity model was used to simulate and calculate the concentrations of PFOS in local air, water, soil and sediment. Physical and chemical parameters of PFOS and environmental parameters of Shenzhen were entered into the model. The simulated concentrations were compared with actual measurements to validate the model, and then analyzed based on the transfer flux of PFOS between media to identify the main transfer route. The input parameters and output results of the model underwent sensitivity analysis and uncertainty analysis, respectively. The simulated concentrations of PFOS in air, water, soil and sediment were 1.4 pg·m-3, 7.0 ng·L-1, 0.39 µg·kg-1 and 0.11 µg·kg-1, in good agreement with the actual measurements. The transfer from air to soil, soil to water and air to water were the main PFOS transfer routes between media, accounting for 32%, 32%, 5.8% of total transfer, respectively. The transfer through water was the major PFOS outlet from a region. The advective input of air and water, temperature, PFOS solubility, precipitation and density of soil and sediment were the key parameters affecting the model output. Uncertainty analysis showed that the coefficient of variation of PFOS concentrations reached the minimum in water and the maximum in soil, which may be caused by the highly changeable content of organic carbon in soil.

The soybean GmDi19-5 interacts with GmLEA3.1 and increases sensitivity of transgenic plants to abiotic stresses.

Drought-induced (Di19) proteins played important roles in plant growth, development, and abiotic stress responses. In the present study, a total of seven Di19 genes were identified in soybean. Each soybean Di19 gene showed specific responses to salt, drought, oxidative, and ABA stresses based on expression profiles. With a relatively higher transcript level among Di19 members under four stress treatments, GmDi19-5 was selected for detailed analysis. Inhibitor assays revealed that ABA inhibitor (Fluridone) or H2O2 inhibitor (DMTU) was involved in the drought- or salt-induced transcription of GmDi19-5. The GUS activity driven by the GmDi19-5 promoter was induced by salt, PEG, ABA, and MV treatments and tended to be accumulated in the vascular bundles and young leaves. A subcellular localization assay showed that GmDi19-5 protein localized in the nucleus. Further investigation showed that GmDi19-5 protein was involved in the interaction with GmLEA3.1. Overexpression of GmDi19-5 increased sensitivity of transgenic Arabidopsis plants to salt, drought, oxidative, and ABA stresses and regulated expression of several ABA/stress-associated genes. This present investigation showed that GmDi19-5 functioned as a negative factor under abiotic stresses and was involved in ABA and SOS signaling pathway by altering transcription of stress-associated genes.

A highly enantioselective and regioselective organocatalytic direct Mannich reaction of methyl alkyl ketones with cyclic imines benzo[e][1,2,3]oxathiazine 2,2-dioxides.

A highly enantioselective direct Mannich reaction of methyl alkyl ketones with cyclic imines benzo[e][1,2,3]oxathiazine 2,2-dioxides, catalyzed by the combination of cinchona alkaloid derived primary amine and TFA, is disclosed. For unsymmetrical methyl alkyl ketones, it is favoured that specific regioselective addition to the imine substrates occurs at the less-substituted methyl group by steric control.

[Study on high-temperature phase change of tobermorite].

In the present paper, the high-temperature phase change of pure tobermorite was investigated by TGA/DSC, X-ray diffraction and infrared spectroscopy (IR) respectively. The DSC results showed that four interlayer water molecules were lost when they were heated at 300 degrees C. As the temperature increased to 724 degrees C, Si-O-H bonds were cleaved and dehydroxylation occurred. The XRD results showed that many diffraction peaks o f tobermorite disappeared and the crystal structure was broken and collapsed. Then tobermorite tends to be disordered and amorphous. When the calcination temperature increased to 861 degrees C, the disordered structure recombined to wollastonite, and the crystal structure became ordered and stable. Finally, the structure completely transformed to 2M-wollastonite at 1 000 degrees C. It should include the process of high-temperature phase change of tobermorite: tobermorite --> dehydration tobermorite --> dehydroxylation tobermorite --> wollastonite.

[Impact of glutamine and ω-3 polyunsaturated fatty acids on intestinal permeability and lung cell apoptosis during intestinal ischemia-reperfusion injury in a rat model].

OBJECTIVE: To investigate the impact of intestinal lymphatic vessels ligation and different enteral nutrition support during ischemia/reperfusion on intestinal permeability, systemic inflammatory response and pulmonary dysfunction in a rat model. METHODS: Seventy-two Sprague-Dawley male rats were randomized into normal diet group, regular enteral nutrition group, glutamine-enriched group, 0-3 polyunsaturated fatty acids (wo-3PUFA) group, and sham control after gastrostomy. All the enteral nutrition group were isocaloric (1046 kJ kg-' d-1) and isonitrogenous (1.8 g N kg-' d-'). After enteral nutrition for 7 days, the rats were subjected to intestinal ischemia for 60 min, or ischemia plus mesenteric lymph duct ligation except for the sham group followed by 3 days of nutrition (72 h). Intestinal permeability (lactose/mannitol ratio in the urine, L/M) was determined on the 5th, 7th and 9th day after gastrostomy. The levels of serum diamine oxidase, endotoxin, cytokines, ALT and AST were detected at the 11th day after gastrostomy. Mucosal thickness was measured using small intestine and villusheight. Myeloperoxidase (MPO), nitric oxide (NO), NO synthase, and apoptotic index were detected in lung tissue. RESULTS: Ischemia for 60 min could cause intestinal injury. Intestinal permeability(L/M)was increased significantly in every group on the first day after ischemia (P<0.05). However, L/M decreased significantly 3 days after ischemia (P<0.05). The groups with Glu and o-3PUFA-enriched nutrition almost restored to normal level (P>0.05). The level of L/M in lymphatic ligation group was significantly lower than non-ligation group (P<0.05). The levels of endotoxin and cytokine were reduced, mucosal thickness and villous height were significantly higher (P<0.05) in the groups of Glu and o-3PUFA-enriched nutrition compared with enteral nutrition and normal diet groups during intestinal ischemia-reperfusion injury. MPO, NO, NOS and the apoptosis index of lung tissue decreased in the groups of Glu and o-3PUFA-enriched as well as after lymph duct ligation (P<0.05). CONCLUSIONS: The distant tissue-lung damage and systemic inflammation caused by intestinal ischemia-reperfusion injury may be related to some factors in the intestinal lymph. Blocking the gut-lymph pathway and/or adding Glu and o-3PUFA in enteral nutrition may reduce intestinal permeability and endotoxin, increase mucosal thickness, attenuate the systemic inflammatory reaction, and prevent lung injury

Nutrients removal and recovery from anaerobically digested swine wastewater by struvite crystallization without chemical additions.

Anaerobically digested swine wastewater contains high concentrations of phosphorus (P) and nitrogen (N). A pilot-scale experiment was carried out for nutrients removal and recovery from anaerobically digested swine wastewater by struvite crystallization. In the pilot plant, a sequencing batch reactor (SBR) and a continuous-flow reactor with struvite accumulation devices were designed and employed. The wastewater pH value was increased by CO(2) stripping, and the struvite crystallization process was performed without alkali and Mg(2+) additions. Results of the long-term operation of the system showed that, both reactors provided up to 85% P removal and recovery over wide ranges of aeration times (1.0-4.0 h), hydraulic retention times (HRT) (6.0-15.0 h) and temperatures (0-29.5°C) for an extended period of 247 d, in which approximate 30% of P was recovered by the struvite accumulation devices. However, 40-90% of NH(4)(+)-N removed was through air stripping instead of being immobilized in the recovered solids. The recovered products were detected and analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and chemical methods, which were proved to be struvite with purity of more than 90%. This work demonstrated the feasibility and effects of nutrients removal and recovery from anaerobically digested swine wastewater by struvite crystallization without chemical additions.

The remediation of heavy metals contaminated sediment.

Heavy metal contamination has become a worldwide problem through disturbing the normal functions of rivers and lakes. Sediment, as the largest storage and resources of heavy metal, plays a rather important role in metal transformations. This paper provides a review on the geochemical forms, affecting factors and remediation technologies of heavy metal in sediment. The in situ remediation of sediment aims at increasing the stabilization of some metals such as the mobile and the exchangeable fractions; whereas, the ex situ remediation mainly aims at removing those potentially mobile metals, such as the Mn-oxides and the organic matter (OM) fraction. The pH and OM can directly change metals distribution in sediment; however oxidation-reduction potential (ORP), mainly through changing the pH values, indirectly alters metals distribution. Mainly ascribed to their simple operation mode, low costs and fast remediation effects, in situ remediation technologies, especially being fit for slight pollution sediment, are applied widely. However, for avoiding metal secondary pollution from sediment release, ex situ remediation should be the hot point in future research.