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A wide pitch gradient covering the near infrared region (750.0–2500.0 nm) were facilely obtained by simple controlling temperature difference to LC mixtures with a twist grain boundary (TGB)–N* phase transition. After the pitch gradient formed, the structure of broad reflective bandwidth was fixed through polymerisation of monomers in mixtures by UV irradiation. It was found that the temperature difference between the up and down side of the samples was critical to form wide-pitch gradient distribution. Additionally, the reflection wavelength and bandwidth of films could be adjusted by the applied temperature difference with the widest bandwidth up to 1750 nm. This simple method for the preparation of broad reflective films was expected to be used in the fields like architectural energy conservation or infrared shield. [ABSTRACT FROM PUBLISHER]

Statistical characteristic analysis of pollutants in contaminated sites can help identify the origin, generation, and spatial variation of different pollutants, and can reduce the uncertainty of site survey data. Taking a large and abandoned contaminated coking site of China as the object, 114 surface (0-50 cm) soil samples were collected, with the statistical and spatial characteristics of 16 priority PAHs (ΣPAHs) analyzed. The descriptive statistical analysis indicated that the Σ PAH levels varied significantly, and the data were severely skewed. The correlation matrix (CM) and principal component analysis (PCA) showed that the extracted first two principal components (PCs) could effectively represent the whole site pollution data. Four pollutants, i. e. , Baa, Bbf&Bkf, Bap, and Inp, were selected for trend analysis and spatial local variance analysis. In the east-west and north-south directions of the site, the pollution showed a low-high-low trend. The variation coefficient of pollution for the site was higher in the central, northwest, and southwest regions, while lower in the other regions. [ABSTRACT FROM AUTHOR]

Cold鄄adapted microorganisms such as psychrotrophs and psychrophiles widely exist in the soils of sub鄄Arctic, Arctic, Antarctic, alpine, and high mountains, being the important microbial resources for the biodegradation of petroleum hydrocarbons at low temperature. Using the unique advantage of cold鄄adapted microorganisms to the bioremediation of petroleum hydrocarbon鄄contaminated soils in low temperature region has become a research hotspot. This paper summarized the category and cold鄄adaptation mechanisms of the microorganisms able to degrade petroleum hydrocarbon at low temperature, biodegradation characteristics and mechanisms of different petroleum fractions under the action of cold鄄adapted microorganisms, bio鄄stimulation techniques for improving biodegradation efficiency, e. g. , inoculating petroleum鄄degrading microorganisms and adding nutrients or bio鄄surfactants, and the present status of applying molecular biotechnology in this research field, aimed to provide references to the development of bioremediation techniques for petroleum hydrocarbon鄄contaminated soils. [ABSTRACT FROM AUTHOR]

Soil samples in different depths were collected from Tiebutie pool in Daqing, which was used to take up waste water from a petrochemical plant for about 30 years. The distribution and concentration of polycyclic aromatic hydrocarbons (PAHs) in organo -- mineral aggregates were analyzed. Results show that the concentration of low molecular PAHs is the highest in all fractions, and the Concentration of low molecular PAHs is higher than that of high molecular PAHs in deeper soil. The PAHs concentration in clay fraction is the highest, and the concentration of PAHs is related to the content of soil organic matter. Adsorption is an important transport approach for PAHs in organo -- mineral aggregates. [ABSTRACT FROM AUTHOR]

Two new phenolic glycosides were isolated from the seeds of Cucurbita moschata. Their structures were elucidated as (2-hydroxy)phenylcarbinyl 5-O-benzoyl-β-d-apiofuranosyl(1 → 2)-β-d-glucopyranoside (1) and 4-β-d-(glucopyranosyl hydroxymethyl)phenyl 5-O-benzoyl-β-d-apiofuranosyl(1 → 2)-β-d-glucopyranoside (2) on the basis of spectroscopic analysis and chemical evidence. [ABSTRACT FROM AUTHOR]

In order to evaluate the effects and mechanism of in-situ cement solidification/stabilization (S/S) on heavy metal contaminated soils, leaching tests, speciation analysis, and microscopic analysis were conducted after cement treatment of a Pb, Zn, and Cd contaminated site in Baiyin, China. The leaching test results showed that cement could effectively stabilize Cd and Zn, which could reduce 99.5%-100% and 96.6%-98.8% of H 2 SO 4 -HNO 3 extractable Cd and Zn, respectively. However, the leaching concentration of Pb was 2.6-5.8 times higher than that before 5% cement treatment. After adding 8% cement, H 2 SO 4 -HNO 3 extractable Cd and Zn were reduced by 99.6%-100% and 94.4%-97.9% respectively. Similarly, the leaching concentration of Pb was 1.9-12.5 times higher than that before 8% cement treatment. The results of sequential extraction test proposed by the European Community Bureau of Reference (BCR) showed that cement could transform acid extractable Cd and Zn to residual form and transform reducible fractions of Pb to oxidizable and residual form, increasing the stability of heavy metals in soil. The microscopic analysis results showed that Pb 2+ , Zn 2+ , and Cd 2+ could participate in the process of cement hydration and form silicate minerals and hydroxides. In conclusion, cement could be an effective S/S agent to remediate heavy metal contaminated soils, and site characteristics and environmental conditions should also be considered during the construction process.

Soil remediation technology screening is an important procedure in the supervision of contaminated sites. The efficiency and costs of contaminated site remediation will be directly affected by the applicability of soil remediation technology. The influencing factors include characteristics of contaminants, site conditions, remediation time and costs should be considered to determine the most applicable remediation technology. The remediation technology screening was commonly evaluated by the experienced expert in China, which limited the promotion and application of the decision making method. Based on the supervision requirements of contaminated sites and the research status at home and abroad, the screening method includes preliminary screening and explicit evaluation was suggested in this paper. The screening index system was constructed, and the extension theory was used to divide the technology grade. The extension theory could solve the problem of human interference in the evaluation process and index value assignment. A chromium residue contaminated site in China was selected as the study area, and the applicable remediation technologies were suggested by the screening method. The research results could provide a scientific and technological support for the supervision and management of contaminated sites in China.

Placental trophoblast cells differentiate into invasive trophoblasts or syncytiotrophoblasts. Abnormal trophoblast invasion results in pregnancy-associated disease and abortion. uPAR is a cell membrane-bound glycosylated protein, involved in physiological and pathological processes. However, uPAR expression in villi during threatened abortion and its role in trophoblast differentiation are unclear. We determined that, uPAR expression in the villi was reduced in threatened abortion patients than that in normal pregnancy. uPARsiRNA inhibited the potential for trophoblast migration and invasion in explants culture and HTR8/SVneo cells. It also enhanced forskolin-induced fusion of HTR8/SVneo cells. Overall, this study provides a possible reason for abortion.

Based on previous studies and field investigation of Dagang industry area in Tianjin, a total of 128 topsoil samples were collected, and contents of 10 heavy metals (As, Cd, Cr, Co, Cu, Pb, Ni, V, Zn and Hg) were determined. The geoaccumulation index and geostatistics were applied to examine the degree of contamination and spatial distribution of heavy metals in topsoil. The assessment on ecological risk of heavy metals was carried out using Hakanson's method, and the main resources of the heavy metals were analyzed as well. It was found that As, Cd and Co had the highest proportions exceeding Tianjin background value, which were 100%, 97.66% and 96.88%, respectively; the heavy-metal content increased to some extent comparing with that in 2004, and the pollutions of As and Cd were the worst, and other metals were at moderate pollution level or below. The ecological risks of heavy metals were different in topsoil with different land use types, the farmland soil in the southwest as well as soils adjacent to the industrial land were at relatively high potential ecological risk level, and the integrated ecological risk index reached up to 1 437.37. Analysis of correlation and principal component showed that traffic and transportation as well as agricultural activities might be the main resources of heavy metals in the area, besides, the industrial activities in the region might also affect the accumulation of heavy metals.

Air samples were collected to analyze the distribution of HCHs and DDTs around a contaminated site during its excavation. The carcinogenic risks and non-carcinogenic risks through breath exposure were studied by health risk assessment modes. The results showed that, there was an obvious seasonal variation of HCHs and DDTs in air around the excavating area. The concentrations of HCHs and DDTs were higher in winter and autumn, lower in spring and summer. The Σ HCHs concentration ranged from 5.65 ng x m(-3) to 133 ng x m(-3), and the average value was 28.6 ng x m(-3); Σ DDTs concentration ranged from 4.48 ng x m(-3) to 2 800 ng x m(-3), and the average value was 457.3 ng x m(-3) in winter. However, the Σ HCHs concentration was between 6.23 ng x m(-3) and 26.4 ng x m(-3), and the average value was 15.1 ng x m(-3) in spring; the Σ DDTs concentration was between 3.17 ng x m(-3) and 8.1 ng x m(-3), and the average value was 6.1 ng x m(-3) in summer. So the pollution could be reduced by excavating in spring and summer. The concentrations of HCHs and DDTs in the residents area were negatively correlated to the height (P < 0.05, n = 33 ). The carcinogenic and non-carcinogenic risks of adult residents through respiration to residents near the excavating area were lower than the acceptable level, while the excavating process caused carcinogenic and non-carcinogenic risks to young residents to some extent. In order to decrease the risks, measures should be taken to restrain the pollutants in the excavation area diffusing into the air.

Polybrominated diphenyl ethers (PBDEs) were determined in sediments collected from a river which through an electrical equipment dismantling area. The results showed that concentrations of PBDEs ranged from 101 to 20,400 ng · g(-1) with an average of 3,700 ng · g(-1), and BDE209 was the most dominant homologue accounted for more than 94% of all detected homologues. The concentration of PBDEs was higher in the middle of river than that in upstream and downstream and the average concentration in downstream was higher than the upstream, with a peak of concentration in the area near by dismantling industrial park. PBDEs pollution in this region is relatively serious compared with other regions. It was estimated that 0.39 t PBDEs (including 0.36 t BDE209) was discharged into the river as a result of dismantling industrial activities in last 40 years. A preliminary ecological risk assessment for PBDEs in sediments was conducted by hazard quotient method, the results showed that the OctaBDEs and DecaBDEs were in a low ecological risk, while the PentaBDEs was in a particularly high risk and could cause great harm to the environment.

Groundwater is the main source of water supply in China, and China's overall situation of groundwater pollution is not optimistic at present. Groundwater pollution risk evaluation and early-warning are the effective measures to prevent groundwater pollution. At present, research of groundwater early-warning method at home and abroad is still at the exploratory stage, and the sophisticated technology has not been developed for reference. This paper briefly described the data and technological demand of the early-warning method in different scales, and the main factors influencing the early-warning results of groundwater pollution were classified as protection performance of geological medium, characteristics of pollution sources, groundwater dynamics and groundwater value. Then the main early-warning indexes of groundwater pollution were screened to establish the early-warning model of regional or watershed scale by the index overlay method. At last, the established early-warning model was used in Baotou plain, and the different early-warning grades were zoned by the model. The research results could provide scientific support for the local management department to protect the groundwater resources.

Concentration profiles of polychlorinated biphenyls (PCBs) and toxicity risks of dioxin-like PCBs were investigated in soils collected from a capacitor-burial site. Based on the USEPA model of human health risk assessment, cancer and non-cancer risks for these soils were also estimated when used for residential and industrial purposes. It was observed that the average concentrations of total PCBs (sigma PCBs, 22 congeners) in the soils were 6.23, 19.3, and 1 540 mg x kg(-1) at different depths of 0-30 cm, 30-100 cm, and 200-250 cm, respectively. Tri-CBs and Tetra-CBs were the largest contributors to the total concentrations in the soils, making up 75.7%-94.0%. The toxic equivalent concentration (TEQs) of total PCBs was up to 457 microg x kg(-1), and PCB 126 had the highest contribution. Health risk assessment showed that under residential land uses, children was the most sensitive receptor although cumulative non-carcinogenic risks for both children and adults (0.927-1 760) nearly exceeded the acceptable level, while under industrial land uses except for the topsoil, the total non-carcinogenic risks for workers exceeded the acceptable level. Under residential and industrial land uses, PCBs in the soils had high carcinogenic risks that were more than the acceptable level of carcinogenic risks (10(-6)-10(-5)). Inhalation exposure was the major way subjected to the carcinogenic risk as well as to the non-carcinogenic risk, regardless of children, adults, and workers involved.

The influencing factors of benzene diffusion fluxes from sand and black soil to atmosphere were investigated using a flux chamber (30.0 cm x 17.5 cm x 29.0 cm). In this study, the benzene diffusion fluxes were estimated by measuring the benzene concentrations both in the headspace of the chamber and in the soils of different layers. The results indicated that the soil water content played an important role in benzene diffusion fluxes. The diffusion flux showed positive correlation with the initial benzene concentration and the benzene dissolution concentration for both soil types. The changes of air flow rate from 300 to 900 mL x min(-1) and temperature from 20 degrees C to 40 degrees C resulted in increases of the benzene diffusion flux. Our study of benzene diffusion fluxes from contaminated soils will be beneficial for the predicting model, and emergency management and precautions.

Dyes are frequently used to visualize fingering flow pathways, where the image process has an important role in the result analysis. The theory of fractal geometry is applied to give quantitative description of the stain patterns via image analysis, which is helpful for finger characterization and prediction. This description typically involves two parameters, a mass fractal dimension (D(m)) relative to the area, and a surface fractal dimension (D(s)) relative to the perimeter. This work detailed analyzes the influence of various choices during the thresholding step that transformed the origin color images to binary ones which are needed in the fractal analysis. One hundred and thirty images were obtained from laboratory two-dimension sand box infiltration experiments of four dyed non-aqueous phase liquids. Detailed comparisons of D(m) and D(s) were made respectively, considering a set of threshold algorithms and the filling of lakes. Results indicate that adjustments of the saturation threshold influence are less on both D(m) and D(s) in the laboratory experiments. The brightness threshold adjustments decrease the D(m) by 0.02 and increase the D(s) by 0.05. Filling lakes influence the D(m) less while the D(s) decrease by 0.10. Therefore the D(m) was recommended for further analysis to avoid subjective choices' influence in the image process.

Non-aqueous phase liquids (NAPLs) like petroleum hydrocarbons and chlorinated solvents have resulted in contamination of soils and ground water, which aroused widespread concern. It's quite important to delineate pollution area for remediation according to different soil types with pollutants properties in consideration. In this paper, a two-dimension visual sand box apparatus was constructed, with four typical NAPLs selected for infiltration experiments conducted in initially dry porous media. The main driving force was identified and fingering patterns were compared. The fractal dimension was used to give quantitative description. The present work indicates that the main driving force was capillary forces and the mechanism was the capillary fingering. The fingers varied from skeletal patterns to fleshy patterns and the infiltration area increased when the capillary number and the bond number decreased for NAPLs with the same level of viscosity. The high viscous force resulted in larger finger width and infiltration area. The same change between fluids happened in finer media. Fractal dimensions were positively correlated with the finger width and infiltration area, which is helpful in the pollution area characterization.