Source Apportionment and Health Risk Assessment of Heavy Metals in Soils of Old Industrial Areas-A Case Study of Shanghai, China.

Heavy metals in the soil of industrial areas pose severe health risks to humans after land-use properties are transformed into residential land. The public exposure time and frequency will soar significantly under residential land. However, much uncertainty still exists about the relationship between soil heavy metal pollution and-human health risks in an old industrial zone in Shanghai, China. Principal component analysis-(PCA) was used to explore the main sources of these heavy metals. Kriging interpolation was u-sed to identify their spatial distribution and high-risk areas, and the Human Health risk model was used to measure health risk. The results illustrate that the pollution levels of Cd, Hg, and Pb in industrial land are more serious than those in irrigation cropland. Meanwhile, the results of PCA showed that there were two main pollution sources under irrigated cropland, a natural source and a traffic source, accounting for 44.1% and 31.0%, respectively, and there were three main pollution sources under industrial land, with natural sources accounting for 28.5%, traffic sources accounting for 25.7%, and industrial sources accounting for 13.1%. In addition, the health risk assessment results indicated that the priority control pollutants of non-carcinogenic risk and carcinogenic risk were Zn and Cr, respectively. The high-risk area was mainly located in the middle of the study area. These results indicate that eliminating heavy metal pollution in the soil of the industrial area is so important to decrease health risks. The results of this study provide theoretical contributions to early warning of health risks related to heavy metal pollution in industrial area soil and serve as a practical reference for speeding up the formulation of industrial land pollution management policies.

Ergodic time scale and transitive dynamics in single-particle tracking.

We investigate ergodic time scales in single-particle tracking by introducing a covariance measure Ω(Δ;t) for the time-averaged relative square displacement recorded in lag-time Δ at elapsed time t. The present model is established in the generalized Langevin equation with a power-law memory function. The ratio Ω(Δ;Δ)/Ω(Δ;t) is shown to obey a universal scaling law for long but finite times and is used to extract the effective ergodic time. We derive a finite-time-averaged Green-Kubo relation and find that, to control the deviations in measurement results from ensemble averages, the ratio Δ/t must be neither too small nor close to unity. Our paper connects the experimental self-averaging property of a tracer with the theoretic velocity autocorrelation function and sheds light on the transition to ergodicity.

Comparison of four markers of hepatic fibrosis and hepatic function indices in patients with liver cirrhosis and hepatoma.

BACKGROUND: The present study aimed to compare four hepatic fibrosis markers [i.e., hyaluronic acid (HA), laminin (LN), procollagen III N-terminal peptide (PIIINP), and collagen type IV (CIV)] and 16 hepatic function indices in patients with liver cirrhosis of varying etiology. METHODS: The hepatic function indices and hepatic fibrosis markers were measured in 108 patients with liver cirrhosis and hepatoma using an automatic biochemical analyzer and luminescent immune analyzer. Twenty healthy controls were enrolled to compare the differences between liver cirrhosis and hepatoma of varying etiology and to analyze the correlations between the hepatic function indices and fibrosis markers. RESULTS: There was no correlation between alanine aminotransferase (ALT), total protein (TP), alkaline phosphatase (ALP), or the four markers of hepatic fibrosis in liver cirrhosis caused by hepatitis B (P>0.05). Aspartate aminotransferase (AST) was positively correlated with HA (r=0.428, P=0.007), LN (r=0.458, P=0.004), and CIV (r=0.374, P=0.021). Total bilirubin (TBIL) and direct bilirubin (DBIL) were positively correlated with LN (TBIL: r=0.480, P=0.002; DBIL: r=0.457, P=0.004), PIIINP (TBIL: r=0.380, P=0.017; DBIL: r=0.406, P=0.011), and CIV (TBIL: r=0.415, P=0.010; DBIL: r=0.400, P=0.013). Total bile acid (TBA) and γ-glutamyltranspeptidase (GGT) were positively correlated with PIIINP (TBA: r=0.363, P=0.025; GGT: r=0.353, P=0.029) and CIV (TBA: r=0.419, P=0.009; GGT: r=0.335, P=0.040). Leucine aminopeptidase (LAP) was positively correlated with LN (r=0.482, P=0.002). Cholinesterase (CHE) (HA: r=-0.452, P=0.004, LN: r=-0.336, P=0.039; PIIINP: r=-0.468, P=0.003; CIV: r=-0.485, P=0.002), prealbumin (PA) (HA: r=-0.575, P=0.000, LN: r=-0.413, P=0.010; PIIINP: r=-0.344, P=0.035; CIV: r=-0.371, P=0.022), albumin (ALB) (HA: r=-0.541, P=0.000, LN: r=-0.373, P=0.021; PIIINP: r=-0.353, P=0.030; CIV: r=-0.415, P=0.010), and superoxide dismutase (SOD) (HA: r=-0.334, P=0.040, LN: r=-0.347, P=0.033; PIIINP: r=-0.487, P=0.002; CIV: r=-0.536, P=0.001) were negatively correlated with the four markers of hepatic fibrosis. There was no correlation between ALT, AST, TBIL, TP, ALP, GGT, or the four hepatic fibrosis markers in hepatoma caused by hepatitis B (P>0.05). Meanwhile, DBIL and TBA were positively correlated with CIV (DBIL: r=0.519, P=0.023; TBA: r=0.563, P=0.012), while CHE (r=-0.604, P=0.006), ALB (r=-0.564, P=0.012), and SOD (r=-0.489, P=0.034) were negatively correlated with CIV. Moreover, PA was negatively correlated with LN (r=-0.510, P=0.026) and CIV (r=-0.696, P=0.001). CONCLUSIONS: The concentrations of the serological indices differed significantly based on the specific liver cirrhosis etiology. There was a strong correlation between the hepatic function indices and four hepatic fibrosis markers. Thus, the detection of these markers might improve the diagnosis and treatment of hepatoma.

A Novel PCR Method for Detecting ACE Gene Insertion/Deletion Polymorphisms and its Clinical Application.

BACKGROUND: Angiotensin-converting enzyme (ACE) plays a major role in blood pressure regulation and cardiovascular homeostasis. The wide distribution and multifunctional properties of ACE suggest it's involvement in various pathophysiological conditions. RESULTS: In this study, a novel visual detection method for ACE I/D polymorphisms was designed by integrating direct PCR without the need for DNA extraction using gold magnetic nanoparticles (GMNPs)-based lateral flow assay (LFA) biosensor. The entire detection procedure could enable the genotyping of clinical samples in about 80 min. The detection limit was 0.75 ng and results could be obtained in 5 min using the LFA device. Three hundred peripheral blood samples were analyzed using the direct PCR-LFA system and then verified by sequencing to determine accuracy and repeatability. A clinical preliminary study was then performed to analyze a total of 633 clinical samples. CONCLUSIONS: After grouping based on age, we found a significant difference between the genotypes and the age of patients in the CHD group. The introduction of this method into clinical practice may be helpful for the diagnosis of diseases caused by large fragment gene insertions/deletions.

Hexagonal layered group IV-VI semiconductors and derivatives: fresh blood of the 2D family.

New phases of group IV-VI semiconductors in 2D hexagonal structures are predicted and their unusual physical properties are revealed. The structures of monolayer group IV-VI semiconductors are similar to those of blue phosphorene and each unit has the same ten valence electrons. The band gap of 2D hexagonal group IV-VI semiconductors depends on both the thickness and stacking order. Atomic functionalization can induce ferromagnetism, and the Curie temperature can be tuned. Gapped Dirac fermions with zero mass are developed and this makes it exceed that of graphene. The Fermi velocity can be compared to or even above that of graphene.

[Spatial response of lake water quality to multi-scale landscape pattern of lakeside zone in agricultural watershed].

Understanding the response of water quality in lake to landscape pattern at different spatial scales in agricultural watershed is of great significance to water quality management. In this study, we classified seven riparian buffer zones of lakeside zone by ArcGIS and RS in the Honghu Lake, according to the five functional areas. The landscape metrics were analyzed at multiple buffer widths using Fragstats software. Mathematical statistical methods and models such as redundancy analysis were used to explore spatial relationship between water quality and landscape patterns. Results showed that: 1) The effect of landscape patterns on water quality was scale-dependent at multiple buffer widths. The highest total explanatory power between landscape characteristics and water quality was found at the 200 m buffer width, accounting for 86.1% of the total, which was the most effective spatial scale affecting water quality. 2) The landscape configuration (e.g., largest patch index, patch density) was more associated with water quality than landscape composition (e.g., the percent of landscape and evenness index). 3) The impacts of different landscape types on water quality varied. Agriculture land, affected by topography and cultivation mode, was the main influencing factor on the degradation of water quality at smaller buffer widths from 100 m to 500 m. Forests with higher density and area had more purification effect on water pollutants at the wider buffer widths from 1000 m to 5000 m. The impacts of grassland on water quality was similar with that of forests, but densely distributed urban land contributed to water quality degradation at the same buffer widths. This study could provide scientific reference for water quality management and landscape planning of lake basin in agricultural areas.

Highly Tunable Electronic Structures of Phosphorene/Carbon Nanotube Heterostructures through External Electric Field and Atomic Intercalation.

Black phosphorene (BP)/carbon nanotube (CNT) heterostructures can be classified as either type I or II, depending on the size of the CNTs. An external electric field (Eext) can modulate the interfacial electronic structures and separate the electron and hole carriers of the BP/CNT heterostructures. The giant Stark effect is observed, and the band gap of the semiconducting heterostructures can vary several-fold. The intercalation of 3d transition metals can strongly bond BP and CNTs together. Furthermore, strong ferromagnetism with Curie temperature (TC) above room temperature is predicted. It is expected that these BP/CNT heterostructures will provide new opportunities and applications in the fields of optoelectronics and electronics as well as spintronics.

[Spatial Variability Characteristics of Water Quality and Its Driving Forces in Honghu Lake During High Water-level Period].

Based on the high-density analysis of 139 monitoring points and samples in water of honghu lake with different degrees of eutrophication during the high water-level period, we could get the figures of spatial variability characteristics of pollution factors, the biomass of aquatic plants and water quality in Honghu Lake using the GIS interpolation methods. The result showed that the concentrations of TN, TP, NH4(+) -N, permanganate index gradually increased from south to north during this period, the trend of water pollution degree in Honghu Lake was the region of inflowing rivers > enclosure culture area > open water area > the lake protection area > region of the Yangtze river into the lake; and the contribution rate of water quality parameters was in the order of TN > TP > permanganate index > NH4(+), -N > DO; under the influence of industrial sewage, agricultural sewage, domestic sewage, bait, aquatic plants and water exchange, 59% of TN, 35.2% of TP, 13.7% of permanganate index, 4.3% of NH4(+)-N exceeded the water quality targets, respectively, accordingly, 66.2% of the water quality also exceeded the water quality target. Nonetheless, DO reached the water quality target due to the influences of monsoon climate and other environment factors. The spatial variation analysis could directly reflect the mutual interaction among human activity, land-use types and environment factors which had an enormous impact on Honghu Lake water environment. In order to ensure that the lake water environment is beneficial for human productions and livings, it is necessary for us to control the discharge of industrial sewage, agricultural sewage and domestic sewage, as well as the expanding area of aquaculture, all the above measures would be significant for gradually resuming the self-purification capacity of water body and finally achieving the ecological sustainable development of Honghu Lake water environment.

Land use pattern, socio-economic development, and assessment of their impacts on ecosystem service value: study on natural wetlands distribution area (NWDA) in Fuzhou city, southeastern China.

This paper quantifies the allocation of ecosystem services value (ESV) associated with land use pattern and qualitatively examined impacts of land use changes and socio-economic factors on spatiotemporal variation of ESV in the Natural Wetland Distribution Area (NWDA), Fuzhou city, China. The results showed that total ESV of the study area decreased from 4,332.16 × 10(6) RMB Yuan in 1989 to 3,697.42 × 10(6) RMB Yuan in 2009, mainly due to the remarkable decreases in cropland (decreased by 55.3 %) and wetland (decreased by 74.2 %). Forest, water, and wetland played major roles in providing ecosystem services, accounting for over 90 % of the total ESV. Based on time series Landsat TM/ETM+ imagery, geographic information system, and historical data, analysis of the spatiotemporal variation of ESV from 1989 to 2009 was performed. It indicated that rapid expansion of urban areas along the Minjiang River resulted in significant changes in land use types, leading to a dramatic decline in ecosystem services. Meanwhile, because of land scarcity and unique ecosystem functions, the emergency of wetland and cropland protection in built-up area has become an urgent task of local authorities to the local government. Furthermore, there was still a significant negative correlation between ESV of cropland and wetland and the GDP. The results suggest that future planning of land use pattern should control encroachment of urban areas into cropland and wetland in addition to scientific and rational policies towards minimizing the adverse effects of urbanization.

Three-dimensional topological insulator in a magnetic field: chiral side surface states and quantized Hall conductance.

Low energy excitation of surface states of a three-dimensional topological insulator (3DTI) can be described by Dirac fermions. By using a tight-binding model, the transport properties of the surface states in a uniform magnetic field are investigated. It is found that chiral surface states parallel to the magnetic field are responsible for the quantized Hall (QH) conductance (2n + 1)e²/h multiplied by the number of Dirac cones. Due to the two-dimensional nature of the surface states, the robustness of the QH conductance against impurity scattering is determined by the oddness and evenness of the Dirac cone number. An experimental setup for transport measurement is proposed.

A sustainable landscape ecosystem design: a case study.

Landscape planning is clearly ecologically and socially relevant. Concern about sustainability between human and environment is now a driving paradigm for this professional. However, the explosion of the sustainable landscape in China is a very recent phenomenon. What is the sustainable landscape? How is this realized in practice? In this article, on the basis of the reviews of history and perplexities of Chinese landscape and nature analysis of sustainable landscape, the ecothinking model, an implemental tool for sustainable landscape, was developed, which applies ecothinking in vision, culture, conservation and development of site, and the process of public participation for a harmonious relationship between human and environment. And a case study of the south entrance of TongNiuling Scenic Area was carried out, in which the most optimum scenario was chosen from among three models according to the ecothinking model, to illustrate the construction of the ecothinking model and how to achieve a sustainable landscape.

Expression and characterization of Momordica Chanrantia anti-hyperglycaemic peptide in Escherichia coli.

A nucleic acid sequence MC, encoding Momordica Chanrantia anti-hyperglycaemic peptide MC6 (accession: AAX06814) synthesized according to Escherichia coli preferred codons, was cloned and expressed in E. coli. Recombinant protein pQE8-MC (about 3.5 kDa) was purified and analyzed by 20% SDS-PAGE and western blot. It revealed that the expressed pQE8-MC had good solubility in aqueous media. An HPLC assay was used to confirm the expression of pQE8-MC. Subsequent pharmacological activity assay revealed a significant hypoglycemic effect of low dose treatments of pQE8-MC on male kunming mice. Four hours after an intravenous tail injection, the blood sugar levels of mice treated with pQE8-MC saline solution A3 (1 mg/kg BW) decreased greatly (P < 0.01) relative to the levels of a control group. This suggests that pQE8-MC, expressed in bioengineered E. coli, has a similar hypoglycemic function to the natural protein MC6 from M. Chanrantia. These results reveal the possibility of using bio-engineered bacteria as an anti-diabetic agent.

Rapid Urbanization and Implications for Flood Risk Management in Hinterland of the Pearl River Delta, China: The Foshan Study.

The purpose of this paper is to examine the linkage between rapid urbanization and flood risk in the hinterlands of the Pearl River Delta, P.R. China. Foshan, a typical hinterland city in the Pearl River Delta region, was selected as a case study. Land use and cover change in Foshan during 1988-2003 was analyzed using remote sensing and geographic information system (GIS) techniques. Furthermore, analysis on historical hydrological data during 1962-2005 was performed. Results show that rapid urbanization has resulted in losses of farmland, forest and shrub since 1988. In addition, in order to compensate or offset the loss of farmland due to rapid urban expansion, more than 30 % of the forest and 20 % of the shrub areas were transformed into farmlands. Inevitably, both the urban and agricultural lands increased the pressure on the drainage systems. Furthermore, over the past decades human activities such as dredging up the floodways, excavating sand and building water facilities in the rivers, significantly changed the hydrological conditions, and therefore impaired the rivers' capacity to buffer floods. Lessons from the Foshan case implied that, in addition to natural processes, human activities driven by socio-economic factors should be considered responsible for the recently increasing level of flood risks. Both economically and environmentally, it is irrational and impractical to encourage encroachment of lands vulnerable to floods. It is also realistic and urgent to effectively prevent and control the adverse ecological consequences of urbanization and economic activities for building their wealth and prominence.

Isolation and algae-lysing characteristics of the algicidal bacterium B5.

Water blooms have become a worldwide environmental problem. Recently, algicidal bacteria have attracted wide attention as possible agents for inhibiting algal water blooms. In this study, one strain of algicidal bacterium B5 was isolated from activated sludge. On the basis of analysis of its physiological characteristics and 16S rDNA gene sequence, it was identified as Bacillus fusiformis. Its algaelysing characteristics on Microcystis aeruginosa, Chlorella and Scenedesmus were tested. The results showed that: (1) the algicidal bacterium B5 is a Gram-negative bacterium. The 16S rDNA nucleotide sequence homology of strain B5 with 2 strains of B. fusiformis reached 99.86%, so B5 was identified as B. fusiformis; (2) the algal-lysing effects of the algicidal bacterium B5 on M. aeruginosa, Chlorella and Scenedesmus were pronounced. The initial bacterial and algal cell densities strongly influence the removal rates of chlorophyll-a. The greater the initial bacterial cell density, the faster the degradation of chlorophyll-a. The greater the initial algal cell density, the slower the degradation of chlorophyll-a. When the bacterial cell density was 3.6 x 10(7) cells/ml, nearly 90% of chlorophyll-a was removed. When the chlorophyll-a concentration was less than 550 microg/L, about 70% was removed; (3) the strain B5 lysed algae by secreting metabolites and these metabolites could bear heat treatment.

Microbial remediation and optimization of oil polluted wetlands at Dalian Bay in China.

OBJECTIVE: The wetland at Dalian Bay in the Northeast of China has been polluted by oil severely. The effect of various microbes and operation parameters on the bioremediation of oil-polluted wetlands at Dalian Bay was investigated and reported previously. In the study, other operation conditions related to the status of medium were investigated via statistical experimental design and analysis and a necessary information is involved to use micro-technology in the application. METHODS: The method used involved the direct inoculation of selected bacteria, which were capable of degrading oil. The operation conditions were further optimized and evaluated by gravimetrical assay. RESULTS: The optimal pH and temperature for the studied bacteria to degrade the existing oil pollutants were established as pH 8.0 and 27 degrees C. The mixed of various bacteria showed better results in terms of oil degradation than any single one. Among the selected four factors, disturbance, oxidant, nutrients, and biosurfactant, the former two contributed more impacts on the oil degradation in the early stage of process, while the latter two became the limiting factors in the late stage. Three sets of optimal conditions were obtained for each individual stage, but no one was suitable for the overall process. CONCLUSION: The study demonstrated the technical feasibility of using direct inoculation into the contaminated soil samples to remove oil pollutants. It suggested that the operation conditions should be monitored and adjusted during the different stages of bio-reactions in the process to achieve the best result of oil degradation.

Molecular cloning of a novel LOS2 gene from Capsella bursa-pastoris.

A new LOS2 gene was cloned from C. bursa-pastoris by rapid amplification of cDNA ends (RACE). The full-length cDNA of C. bursa-pastoris LOS2 gene (designated as Cblos2) was 1694 bp containing a 1332 bp open reading frame (ORF) encoding a 444 amino acid protein. The predicted CbLOS2 protein contained enolase-N domain, enolase domain, conserved putative DNA-binding and repression domains like LOS2 from A. thaliana. Bioinformatic analysis indicated that CbLOS2 had similarity with other enolase proteins. Cold acclimation assay revealed that Cblos2 expressed constitutively in C. bursa-pastoris and was involved in the cold acclimation process, implying CbLOS2 was a bi-functional enolase.

Quantum growth of magnetic nanoplatelets of Co on Si with high blocking temperature.

Self-organized Co nanoplatelets with a singular height, quantized lateral sizes, and unique shape and orientation have been fabricated on a template consisting of ordered Al nanocluster arrays on Si(111)-7 x 7 surfaces. Despite their small volume (a few nm(3)), these nanomagnets exhibit an unusually high blocking temperature (>100 K). The perpendicular direction for easy magnetization, the high blocking temperature, the size tunability, and the epitaxial growth on Si substrates make these nanomagnets important for applications in information technology.