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.

Derivation of copper water quality criteria in Bohai Bay for the protection of local aquatic life and the ecological risk assessment.

Developing effective marine water quality criteria (WQC) is crucial for controlling marine contamination and protecting marine life. The WQC for copper is urgently needed due to the toxicity and widespread of copper contamination. In this work, both short-term water quality criteria (SWQC) and long-term water quality criteria (LWQC) under 10 % effect endpoints were derived by using the model averaging of species sensitivity distribution (SSD10) method for Bohai Bay. The WQC values were obtained directly from the hazardous concentration for 5 % of species (HC5) values, which removes the influence of arbitrary assessment factor (AF). Modifications to the acute-chronic ratio (ACR) strategies and the inclusion of the test toxicity data of local species also improved the accuracy and applicability of the WQC values. The derived SWQC and LWQC were 2.21 and 0.45 µg/L, respectively. Furthermore, the overall risk level of copper in Bohai Bay was evaluated by using the risk quotient (RQ) method, and the results showed it was at a moderate-low level. This study provides a new approach for the derivation of the WQC for Cu and the risk assessment of Bohai Bay, which is essential for the protection of local aquatic life and provides guidance to the establishment of the national WQC.

Risks of applying mobilising agents for remediation of arsenic-contaminated soils: Effects of dithionite-EDTA and citric acid on arsenic fractionation, leachability, oral bioavailability/bioaccessibility and speciation.

Arsenic (As) mobilisation assists in remediating As-contaminated soils but might increase ecological and health risks. In this study, risks of applying two mobilising agents were assessed, i.e. an emerging reducing-chelating composite agent [dithionite (Na2S2O4)-EDTA] and a classical low-molecular-weight organic acid (LMWOA) [citric acid (C6H8O7)]. Results showed that both agents induced sharp increase in leachability-based ecological risk of As. Interestingly, the two agents had opposite performances regarding health risks. Na2S2O4-EDTA significantly increased As relative bioavailability (RBA) to 1.83 times that in controls based on in vivo mouse model, and As bioaccessibility to 1.96, 1.65 and 1.20 times in gastric, small intestinal and colon phases based on in vitro PBET-SHIME model. Besides, it caused significant increase of highly toxic As(Ⅲ) in colon fluid. In contrast, C6H8O7 significantly reduced RBA and bioaccessibility of soil As in colon by 44.44% and 14.65%, respectively. Importantly, C6H8O7 restrained bioaccessible As(V) reduction and promoted bioaccessible As(Ⅲ) methylation, further reducing health risk. The phenomena could mainly be attributed to excessive metal components release from soil by C6H8O7 and gut microbiota metabolism of C6H8O7. In summary, C6H8O7 and similar LMWOAs are recommended. The study contributes to mobilising agent selection and development and provides a reference for managing remediation sites.

Derivation of copper water quality criteria in the Bohai Sea of China considering the effects of multiple environmental factors on copper toxicity.

Copper has become one of the most important heavy metal pollutants in the environment because of its wide application and high toxicity, but research on water quality criteria (WQCs) on copper is limited, especially the derivation of seawater WQC. In addition, the toxicity of copper in the seawater system is affected by various environmental factors. Therefore, establishing a WQC that meets the characteristics of the regional environment is a top priority. The correlations between four factors of temperature, salinity, pH, dissolved organic carbon (DOC) and the toxic effect values of copper were analyzed in this study, and the temperature was determined as the most influential factor among the four factors in the Bohai Sea. A specific correlation between temperature and the toxic effects of copper was identified, and WQCs were derived based on the identified correlation and the variations of the Bohai Sea's temperature in different seasons by species sensitivity distribution (SSD) method. Under the condition of the winter, spring, autumn, and summer with an average water temperature of 0.09, 15.96, 17.83, and 24.87 °C, the obtained short-term water quality criteria (SWQCs) were 44.29, 4.70, 4.31, and 3.33 µg/L; the long-term water quality criteria (LWQCs) were 18.14, 1.93, 1.77 and 1.36 µg/L. The findings indicated the importance of introducing specific environmental conditions during the derivation process. This work could provide valuable information for pollution prevention and aquatic life protection in the Bohai Sea and provide a valuable reference for the derivation of criteria in other regions alike.

Establishment of a comprehensive method to derive seawater quality criteria of BDE-47 in China.

2,2',4,4'-tetrabromodiphenyl ether (BDE-47) is an emerging toxic organic pollutant widely detected in territorial waters. Accordingly, establishing the seawater quality criteria (SWQC) for BDE-47 is of significant importance to protect the marine ecosystems. In this study, published ecotoxicity data of BDE-47 to aquatic species in China were collected, and acute and chronic toxicity tests were carried out on saltwater aquatic organisms from 5 phyla and 8 families widely existed in the Chinese marine environment. Static acute toxicity tests and renewed chronic toxicity tests were adopted. The scientific theories and technical methods of the United States Environmental Protection Agency (US EPA), Canada, the European Union (EU), and the Netherlands on water quality criteria guidelines, as well as the Chinese freshwater quality criteria guidelines were compared. Then an integrated method of SWQC derivation was introduced through comprehensive consideration. Afterward, the SWQC of BDE-47 was derived based on the ecotoxicity data. The SWQC includes short-term seawater quality criteria (S-SWQC), long-term seawater quality criteria (L-SWQC), and serious risk concentration for the ecosystem (SRCeco). And they were derived and recommended as 7.90 µg/L, 0.217 µg/L, and 3.65 µg/L, respectively. This study served as a specific example to quantitatively studies the differences between different scientific theories and technique methods. The derivation process and improvement of SWQC for BDE-47 provide support for the future revision of water quality criteria in China.

[Effects of Aging on the Cd Adsorption by Microplastics and the Relevant Mechanisms].

It has been verified that, as an emerging contaminant, microplastics are capable of adsorbing certain traditional contaminants like the heavy metal Cd. However, the majority of previous studies only focused on certain types of virgin microplastics, especially for PE and PS. In addition, this adsorption process might be affected by microplastics inevitably undergoing aging and consequent changes in the natural environment. Unfortunately, the relevant reports on aging effects were mainly about organic pollutants, rather than heavy metals. By far, there have been few comprehensive and mechanistic studies on the key aging effects on the Cd adsorption by various types of microplastics. In this study, five representative types of microplastics (i.e., PS, ABS, PP, PVC, and PET) were selected for aging by ultraviolet radiation, and the physicochemical properties of virgin and aged microplastics were thoroughly compared, including specific surface area, crystallinity, surface functional groups, and surface elements. Accordingly, the changes in adsorption isotherms of Cd by microplastics were discussed. The results showed that:① aging induced non-significant changes in specific surface area but a significant decrease in crystallinity. Surface functional groups also changed, including the emergence of a C=O functional group on PS and ABS, the decrease in C=C absorption peak intensity on ABS, and the increase in absorption peak intensities of C=O, C-O, and polar ester groups on PET. Regarding surface C content, C=C/C-C decreased, whereas C-O and O-C=O increased. The total O content and O/C significantly increased as well. ② The Langmuir model well-fitted the adsorption isotherms of Cd by virgin and aged microplastics. Aging significantly expanded the adsorption capacity of Cd by microplastics, as the order of saturated adsorption capacity before aging was ABS (0.2284 mg·g-1)>PVC (0.1360 mg·g-1)>PS (0.1286 mg·g-1)>PP (0.1005 mg·g-1)>PET (0.0462 mg·g-1) and then became PS (0.2768 mg·g-1)>ABS (0.2586 mg·g-1)>PVC (0.1776 mg·g-1)>PP (0.1721 mg·g-1)>PET (0.0951 mg·g-1) after aging. ③ Both crystallinity and surface functional groups played key roles in the adsorption of Cd by microplastics. As for virgin microplastics, crystallinity was negatively correlated with the saturated adsorption capacity of Cd, because the amorphous regions contributed most to Cd adsorption. Aging brought about the decrease in crystallinity and the increase in amorphous regions, which further promoted the oxidation reaction on microplastics. Consequently, oxygen-containing functional groups increased on the surface and eventually expanded the adsorption capacity of Cd by microplastics. Note that certain specific functional groups of various microplastics also had impacts on the adsorption process. These results provide valuable information about the environmental behaviors and interactions of microplastics and heavy metals in nature.

Cognitive-coping therapy for obsessive-compulsive disorder: a randomized controlled trial.

Pharmacotherapy and cognitive-behavioral therapy (CBT) are widely used to treat obsessive-compulsive disorder (OCD). These treatments have helped many patients with OCD, but there still is room for improvement. Recently, a promising psychotherapy for OCD, cognitive-coping therapy (CCT), has been developed. Pharmacotherapy plus CCT (PCCT) demonstrates higher efficacy in a shorter period of time and lower relapses than pharmacotherapy or pharmacotherapy plus CBT. In this randomized controlled trial, we investigated the efficacy of CCT for OCD treatment. One hundred and forty-five OCD patients were randomly assigned into two groups: pharmacotherapy (N = 72) and PCCT (N = 73). In each group, drug-resistant (DR) and non-drug-resistant (NDR) OCD were further analyzed to examine the efficacy of CCT. Some clinical features and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) were blindly assessed pre-treatment and post-treatment at week 1, 2, 3, 4, and 12. The Y-BOCS scores were significantly lower in PCCT than in the pharmacotherapy group at any post-treatment time-point (P < 0.001). Compared with pre-treatment, the Y-BOCS scores were significantly reduced at any time-point (P < 0.001) in PCCT group, but only at week 12 (P < 0.001) in the pharmacotherapy group. In the PCCT group, there were no differences between DR and NDR groups' Y-BOCS scores at any post-treatment time-point. The response rates and remission rates were higher in PCCT than in the pharmacotherapy group. Three variables, the number of weeks of treatment, insight, and disregarding of obsessions, were significantly correlated with the Y-BOCS score. Therefore, CCT might be a potential treatment for OCD.

Retrospective analysis: the earthquake-injured patients in Barakott of Pakistan.

OBJECTIVE: To provide the experience on medical rescue and care for any giant earthquake by analysing the patients treated by the Chinese Medical Rescue Team in the Barakott earthquake of Pakistan. METHODS: On October 8, 2005, a giant earthquake (7.8 Richter scale) earthquake occurred in the northwest Pakistan. We belonged to the Chinese Medical Rescue Team and worked in the earthquake-affected town---Barakott from October 28, 2005 to November 17, 2005. The patients were classified into upper respiratory tract infection, diarrhea, trauma and other diseases. All the data of patients who were injured during the earthquake were analysed. The difference was analyzed by X(2) test. RESULTS: Of the 2 194 patients treated by the Chinese Medical Rescue Team, trauma patients only accounted for 29%, diarrhea patients for 4%, upper respiratory infection patients for 14%, and other types of diseases for 52%. Among the 630 trauma patients, 426 patients were injured during the earthquake. Of the 426 patients, 291 (68%) patients were found having open wounds, 85 (20%) patients mainly complained of soft tissue pain without any wound or fracture, and 76 (18%) patients had fractures with or without open wound. The most frequent site of wound was lower extremity. Head injury in children was 30%, obviously higher than that in the adults. Wound infection was common among the injured patients, with the rates of 72%, 64% and 78% in male, female adult patients and children, respectively. CONCLUSIONS: Prevalence of common diseases, trauma, wound infection and fracture are main problems presented at late stage of the giant earthquake. Great attention should be paid to head and lower extremity injuries.

[Effect of electroacupuncture on thymocyte apoptosis-related genes in morphine withdrawal rats].

OBJECTIVE: To explore the underlying mechanism of electroacupuncture (EA) in relieving morphine withdrawal syndrome in rats. METHODS: Forty SD rats were randomly divided into normal control group, model group 1, model group 2 and EA group. Morphine withdrawal syndrome model was established by muscular injection of morphine (5 mg/kg on the 1st day, progressively increasing everyday till 100 mg/kg on the 20th day) in the hind limbs. Then, rats of model group 1 were anesthetized (10% chloraldurat) to be killed on the 21st day, and those of model group 2 killed on the 27th day. EA (2/100 Hz, 2-4 mA) was applied to bilateral "Zusanli" (ST 36) for 30 mm, once a day for 7 days. The rat's thymus was removed (after anesthesia), cut into sections (4 pm) and stained with immunohistochemical method for displaying the expression of apoptotic promoters Bax, Fas, Fas Ligand (FasL) as well as anti-apoptotic peptide Bcl-2. RESULTS: Compared with normal group, Bcl-2 immunoreaction (IR)-positive cell number of model group 1 and group 2 decreased significantly while Sax, Fas and FasLIR-positive cell number and Bax/Bcl-2 in two model groups increased considerably (P < 0.01). In comparison with model group 2, Bcl-2 IR-positive cell number of model group 1 decreased significantly (P < 0.05), Bax, Fas and FasL IR-positive cell number and Bax/Bcl-2 of model group 1 were significantly higher (P < 0.01, fl. 05). After EA, in comparison with model group 2, Fas and FasL IR-positive cell number and Bax/Bcl-2 decreased significantly (P < 0.01, 0.05), and Bcl-2 IR-positive cell number increased markedly in EA group (P < 0.05); in comparison with model group 1, Bcl-2 IR-positive cell number increased significantly (P < 0.01), while Bax, Fas and FasL IR-positive cell number and Bax/Bcl-2 decreased evidently in EA group (P < 0.01). CONCLUSION: EA at "Zusanli" (ST 36) can inhibit morphine-induced downregulation of Bcl-2 and upregulation of Fas and FasL expression, which may contribute to its effect in resisting thymus apoptosis in morphine withdrawal rats.

[Comparison of microbial community structure in MBRs treating different wastewater].

In order to investigate the microbial community structures in different membrane bioreactors, total bacterial genomic DNA was extracted from biomass in four MBRs treating different wastewater. The microbial community structures were studied by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and cloning-sequencing. Furthermore, and the sequences were used for homology analysis and then two phylogenetic trees were constructed. Results indicate that each MBR owns its specific ecological community after a long-term of operation. Influent wastewater composition has a significant impact on total bacterial community structures. Population diversity, which is in the bioreactor fed with more complex components wastewater, is higher than those of other MBRs. The Shannon Index are 0.77 and 0.78. Proteobacteria and Bacillus, which contain 8 OUTs and 2 OUTs, are the climax communities in the investigable MBRs. The profiles of ammonia-oxidizing bacterial community in the four reactors are very similar. There may exist several modes of nitrification and denitrification in MBR because sequences revealed that there exist multitude nitrifying organisms, in which Nitrosomonas are the most predominant, and two denitrifying bacterium (uncultured Achromobacter sp. and uncultured denitrifying bacterium)in reactors.

[Expression of alpha-defensin-1 with J chain in the transfected COS-7 cells].

OBJECTIVE: To recombine the alpha-defensin-1 (HNP-1) and J chain cDNA fragment into a new germicidal molecule J-HNP-1, and investigate its expression in the transfected COS-7 cells. METHODS: J chain and HNP-1 cDNA were amplified from the plasmids pCH-J and pBabeNeo-HNP-1 respectively, then the J-HNP-1 DNA fragment was obtained by recombinant polymerase chain reaction (PCR). The J-HNP-1 fragments were inserted into pcDNA3.1 (-)/Myc-HisC, which subsequently was made to transfect the COS-7 cell by lipid transfection method. The expression was confirmed by Western blot. RESULTS: Determination with His antibody, a dense band at 24 ku was displayed by the cell lysate and the cell culture supernatant in concordance with that of the predicted extent, but not in the control. CONCLUSION: The new germicidal peptide J-HNP-1 is found to be expressed intracellularly and could be secreted. The results lay the foundation for further study on the germicidal activity of J-HNP-1.

Intestinal colonization with Candida albicans and mucosal immunity.

AIM: To observe the relationship between intestinal lumen colonization with Candida albicans and mucosal secretory IgA (sIgA). METHODS: A total of 82 specific-pathogen-free mice were divided randomly into control and colonization groups. After Candida albicans were inoculated into specific-pathogen-free mice, the number of Candida albicans adhering to cecum and mucosal membrane was counted. The lymphocyte proliferation in Peyer's patch and in lamina propria was shown by BrdU incorporation, while mucosal sIgA (surface membrane) isotype switch in Peyer's patch was investigated. IgA plasma cells in lamina propria were observed by immunohistochemical staining. Specific IgA antibodies to Candida albicans were measured with ELISA. RESULTS: From d 3 to d 14 after Candida albicans gavaging to mice, the number of Candida albicans colonizing in lumen and adhering to mucosal membrane was sharply reduced. Candida albicans translocation to mesenteric lymph nodes occurred at early time points following gavage administration and disappeared at later time points. Meanwhile, the content of specific IgA was increased obviously. Proliferation and differentiation of lymphocytes in lamina propria were also increased. CONCLUSION: Lymphocytes in lamina propria play an important role in intestinal mucosal immunity of specific-pathogen-free mice when they are first inoculated with Candida albicans. The decreasing number of Candida albicans in intestine is related to the increased level of specific IgA antibodies in the intestinal mucus.

[Clinical significance of serum S-100B protein in severe cerebral injury].

OBJECTIVE: To investigate the value of S-100B protein as a biology marker in diagnosis and prognostic after severe cerebral injury. METHODS: Sixty-six patients with severe head injury (Glasgow coma scale score (GCS)