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Breast cancer is the most common type of cancer amongst women worldwide, and numerous microRNAs (miRNAs/miRs) are involved in the initiation and progression of breast cancer. The aim of the present study was to identify hub miRNAs and determine the underlying mechanisms regulated by these miRNAs in breast cancer. Breast invasive carcinoma transcriptome data (including mRNAs and miRNAs), and clinical data were acquired from The Cancer Genome Atlas database. Differential gene expression analysis, co‑expression network analysis, gene set enrichment analysis (GSEA) and prognosis analysis were used to screen the hub miRNAs and explore their functions. Functional experiments were used to determine the underlying mechanisms of the hub miRNAs in breast cancer cells. The results revealed that low miR150 expression predicted a more advanced disease stage, and was associated with a less favorable prognosis. Through the combined use of five miRNA‑target gene prediction tools, 31 potential miR150 target genes were identified. GSEA revealed that low miR150 expression was associated with the upregulation of several cancer‑associated signaling pathways, and the downregulation of several tumor suppressor genes. Furthermore, miR150 independently affected overall survival in patients, and interacted with its target genes to indirectly affect overall and disease‑free survival. Functional experiments demonstrated that miR150 positively regulated B and T lymphocyte attenuator (BTLA), and the downregulation of miR150 and BTLA combined promoted cell migration. In conclusion, the present study revealed that low miR150 expression was associated with less favorable clinical features, upregulation of several carcinogenic signaling pathways, and poor patient survival. Additionally, a miR150‑BTLA axis was suggested to regulate cell viability and migration.

Dietary preferences were closely associated with the pathogenesis of numbers of metabolic disorders, in particularly, obesity. Dietary fiber was shown to be capable of preventing weight gain and excessive food intake mainly through stimulating chewing and saliva secretion, and promote satiety signals. In this study, we characterized the "Vitamin World® Vegan Meal" Formula of Feihe, a novel protein‐enriched fiber dietary supplement contained potato protease inhibitor II (PI2) that developed. And we demonstrated that this particular fiber formula was effective in preventing weight gain, increasing satiety signals, and reducing food intake in rats in a dosage‐dependent manner. Our study provides lines of evidence and would further bolster the use of this nutritious vegan meal in regulating satiety and food intake in clinics., A novel protein‐enriched fiber dietary supplement contained potato protease inhibitor II was developed. The satiety function evaluation of the fiber vegan product was carried out.

Background Calycosin (CAL), a type of O-methylated isoflavone extracted from the herb Astralagusmembranaceus (AM), is a bioactive chemical with antioxidative, antiphlogistic and antineoplastic activities commonly used in traditional alternative Chinese medicine. AM has been shown to confer health benefits as an adjuvant in the treatment of a variety of diseases. Aim The main objective of this study was to determine whether CAL influences the cytochrome P450 (CYP450) system involved in drug metabolism. Methods Midazolam, tolbutamide, omeprazole, metoprolol and phenacetin were selected as probe drugs. Rats were randomly divided into three groups, specifically, 5% Carboxymethyl cellulose (CMC) for 8 days (Control), 5% CMC for 7 days + CAL for 1 day (single CAL) and CAL for 8 days (conc CAL), and metabolism of the five probe drugs evaluated using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Results No significant differences were observed for omeprazole and midazolam, compared to the control group. T max and t1/2 values of only one probe drug, phenacetin, in the conc CAL group were significantly different from those of the control group (T max h: 0.50±0.00 vs 0.23±0.15; control vs conc CAL). C max of tolbutamide was decreased about two-fold in the conc CAL treatment group (conc vs control: 219.48 vs 429.56, P Conclusion Calycosin inhibits the catalytic activities of CYP1A2, CYP2D6 and CYP2C9. Accordingly, we recommend caution, particularly when combining CAL as a modality therapy with drugs metabolized by CYP1A2, CYP2D6 and CYP2C9, to reduce the potential risks of drug accumulation or ineffective treatment.

The structures, semiconductor and photocurrent response properties of three 1,4-diazabicyclo[2.2.2]octane derivative-templated iodobismuthates, (Et2DABCO)3(BiI6)2 (1), (i-Pr2DABCO)2(Bi2I10) (2), [(Me2DABCO)2(Bi2I10)2] n (3) (Et2DABCO2+ = N,N′-diethyl-1,4-diazabicyclo[2.2.2] octane, i-Pr2DABCO2+ = N,N′-diisoproyl-1,4-diazabicyclo[2.2.2] octane, Me2DABCO2+ = N,N′-dimethyl-1,4-diazabicyclo[2.2.2] octane), are reported. Based on the templates with different substitutents on 1,4-diazabicyclo[2.2.2]octane, mono-nuclear ((BiI6) 3 − for 1), dimer ((Bi2I10) 4 − for 2) and 1-D chain ((BiI5) 2n− for 3) can be obtained. C-H···I hydrogen bonds contribute to the structural extension to 2-D layer (for 2) and 3-D network (for 3). Their absorption spectra were investigated, and energy band gaps of 2.24/1.73/1.44 eV indicate their narrow-gap semiconductor natures. Their photocurrent response properties were also discussed. Finally, theoretical calculation was executed to give structure-properties correlation.

Two novel tetrahedral manganese(II) complexes, (N-methylpiperidinium)MnCl4 (1) and (N-methylpyrrolidinium)MnCl4 (2), with clearly distinct fluorescence characteristics were synthesized through organic cation modulation. Compound 1 exhibits prominent green luminescence with a high quantum yield of 79.37% and 2 emits unusual red emission at 611 nm.

Background Calycosin (CAL), a type of O-methylated isoflavone extracted from the herb Astralagusmembranaceus (AM), is a bioactive chemical with antioxidative, antiphlogistic and antineoplastic activities commonly used in traditional alternative Chinese medicine. AM has been shown to confer health benefits as an adjuvant in the treatment of a variety of diseases. Aim The main objective of this study was to determine whether CAL influences the cytochrome P450 (CYP450) system involved in drug metabolism. Methods Midazolam, tolbutamide, omeprazole, metoprolol and phenacetin were selected as probe drugs. Rats were randomly divided into three groups, specifically, 5% Carboxymethyl cellulose (CMC) for 8 days (Control), 5% CMC for 7 days + CAL for 1 day (single CAL) and CAL for 8 days (conc CAL), and metabolism of the five probe drugs evaluated using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Results No significant differences were observed for omeprazole and midazolam, compared to the control group. Tmax and t1/2 values of only one probe drug, phenacetin, in the conc CAL group were significantly different from those of the control group (Tmax h: 0.50±0.00 vs 0.23±0.15; control vs conc CAL). Cmax of tolbutamide was decreased about two-fold in the conc CAL treatment group (conc vs control: 219.48 vs 429.56, P

Stimuli-responsive materials with coexisting nonlinear optical (NLO) and dielectric properties are technologically important, which enable simultaneous conversion of optoelectronic properties between different states under external stimuli. By rationally screening guest cations (C6H5NF2)+ in the crown-ether inclusion system, we synthesized a crown-ether supramolecular compound [(C6H5NF2)(18-crown-6)][PF6] (1). Differential scanning calorimetry (DSC) showed that 1 undergoes a reversible phase transition above room temperatures (305 K/292 K), with a thermal hysteresis of 13 K. Temperature-dependent dielectric and NLO measurements show that the compound exhibits two distinct switching response behaviors. Structural analysis indicates that the order&ndash, disorder change of the host molecule 18-crown-6 and the guest organic cation during the phase transition induces the dielectric and NLO switching behavior of the compound.

Background Bamboo is one of the most important nontimber forestry products worldwide. However, a chromosome-level reference genome is lacking, and an evolutionary view of alternative splicing (AS) in bamboo remains unclear despite emerging omics data and improved technologies. Results Here, we provide a chromosome-level de novo genome assembly of moso bamboo (Phyllostachys edulis) using additional abundance sequencing data and a Hi-C scaffolding strategy. The significantly improved genome is a scaffold N50 of 79.90 Mb, approximately 243 times longer than the previous version. A total of 51,074 high-quality protein-coding loci with intact structures were identified using single-molecule real-time sequencing and manual verification. Moreover, we provide a comprehensive AS profile based on the identification of 266,711 unique AS events in 25,225 AS genes by large-scale transcriptomic sequencing of 26 representative bamboo tissues using both the Illumina and Pacific Biosciences sequencing platforms. Through comparisons with orthologous genes in related plant species, we observed that the AS genes are concentrated among more conserved genes that tend to accumulate higher transcript levels and share less tissue specificity. Furthermore, gene family expansion, abundant AS, and positive selection were identified in crucial genes involved in the lignin biosynthetic pathway of moso bamboo. Conclusions These fundamental studies provide useful information for future in-depth analyses of comparative genome and AS features. Additionally, our results highlight a global perspective of AS during evolution and diversification in bamboo.

A novel high-temperature dielectric and quadratic nonlinear optical switching material, 3,4-difluoroanilinium 18-crown-6 perchlorate, was synthesized. It exhibits two successive structural phase transitions at 347 K and 240 K, respectively. Gradually increased SHG-active characteristics are also identified.

To evaluate the impacts of anthropogenic events on the rapid urbanized environment, the levels of legacy organochlorine pesticides (OCPs) and current-use insecticides (CUPs), i.e., dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), pyrethroids and organophosphates in soil of the Pearl River Delta (PRD) and surrounding areas were examined. Spatial concentration distributions of legacy OCPs and CUPs shared similar patterns, with higher concentrations occurred in the central PRD with more urbanization level than that in the PRD's surrounding areas. Furthermore, relatively higher concentrations of OCPs and CUPs were found in the residency land than in other land-use types, which may be attributed to land-use change under rapid urbanization. Moderate correlations between gross domestic production or population density and insecticide levels in fifteen administrative districts indicated that insecticide spatial distributions may be driven by economic prosperity. The soil–air diffusive exchanges of DDTs and HCHs demonstrated that soil was a sink of atmospheric o,p′-DDE, o,p′-DDD, p,p′-DDD and o,p′-DDT, and was a secondary source of HCHs and p,p′-DDT to atmosphere. The soil inventories of DDTs and HCHs (100 ± 134 and 83 ± 70 tons) were expected to decrease to half of their current values after 18 and 13 years, respectively, whereas the amounts of pyrethroids and organophosphates (39 and 6.2 tons) in soil were estimated to decrease after 4 and 2 years and then increase to 87 and 1.0 tons after 100 years. In this scenario, local residents in the PRD and surrounding areas will expose to the high health risk for pyrethroids by 2109. Strict ban on the use of technical DDTs and HCHs and proper training of famers to use insecticides may be the most effective ways to alleviate the health effect of soil contamination.

Distributed computing and Resource sharing in large-scale heterogeneous system are the key to realize mobile learning system. This paper sets up a mobile learning service system through the construction of teaching cloud platform and cloud resources, cloud resource sharing, application and service of cloud resource, system and mechanism construction. The mobile learning network system is established by building models of it, which realizes mobile learning, collaborative learning and the situated learning anytime anywhere with freedom, individuality and diversification.

Rapid economic growth in South China (including Guangdong Province, Hong Kong, and Macau), particularly within the Pearl River Delta region, has resulted in severe pollution of the natural eco-environment in the last three decades. Large amounts of monitoring data on organic pollution in the Pearl River Delta have been accumulated, which allows us to conduct a fairly comprehensive assessment of the state of the Pearl River Delta and elucidate spatial and temporal patterns of pollution on a regional scale. Of various causes for environmental deterioration, negative impact from persistent organic pollutants (POPs) is a global concern. This review examines the current levels and distribution patterns of several POPs, namely DDT (and its metabolites DDD and DDE), hexachlorocyclohexanes, and polybrominated diphenyl ethers, in various environmental compartments of South China. The general information on environmental occurrence, regional behaviors, ecological effects, and human exposure of these POPs in this region are reviewed.

Ranunculus L. is an early diverging clade in the Angiosperm phylogeny. The split between terrestrial and aquatic/semi-aquatic lineages within the genus occurred within 20 Ma (Emadzade and Horandl, 2011), which is much younger than for some well-known aquatic lineages such as Ceratophyllum and Potamogeton. Ranunculus sceleratus Linn. is a semi-aquatic plant commonly found in paddy fields, streams and lakes in Asia, Europe and North America (eFlora of China, http://www.efloras.org/). The plant has also been studied for its unique toxicological and pharmacological properties (Prieto et al., 2003). Its karyotype is 2n = 32, x = 8 in mainland China (Yang, 2000). It usually roots in inundated soils, with stems and leaves emergent. The semi-aquatic R. sceleratus has been hypothesized to be an inter-mediate type in the transition from a terrestrial to aquatic habitat within the genus (Barrett et al., 1993; Prieto et al., 2003). In this study, we generated RNA-seq data of R. sceleratus and analyzed this in relation to the RNA-seq data of Ranunculus bungei Steud., Ranunculus cantoniensis DC., and Ranunculus brotherusii Freyn (Chen et al., 2015). Our aim was to generate RNA-seq data of R. sceleratus and identify the orthologous genes among the four species. Links to deposited data RNA-seq data of R. sceleratus was deposited at NCBI sequence Reads Archive (no. SRP072329). It is in SRA format. ITS sequence of R. sceleratus was deposited in GenBank (no. {"type":"entrez-nucleotide","attrs":{"text":"KT957621","term_id":"949478889","term_text":"KT957621"}}KT957621). All the unigenes of R. sceleratus, data matrices of ITS and chloroplast DNA, sequences of the 3455 putative orthologous clusters identified using the program OrthoMCL, and 884 clusters after filters were deposited in figshare (https://figshare.com/s/f40d8f9bd8f894f2d630; sequences in fasta format). These data can be used for further transcriptome assembly, selective pressure estimation, phylogenetic analyses, etc.

Fluoroimmunoassay based on quantum dots (QDs) and magnetic relaxation switch (MRS) immunoassay based on superparamagnetic nanoparticles (SMN) were constructed to detect Salmonella enterica (S. enterica) in water samples. In fluoroimmunoassay, magnetic beads was conjugated with S. enterica capture antibody (MB-Ab2) to enrich S. enterica from sample solution, then the QDs was conjugated with the S. enterica detection antibody (QDs-Ab1) to detect S. enterica based on sandwich immunoassay format. And the fluorescence intensity is positive related to the bacteria concentration of the sample. Results showed that the limit of detection (LOD) of this method was 102 cfu · mL⁻¹ and analysis time was 2 h. In MRS assay, magnetic nanoparticle-antibody conjugate (MN-Ab1) can switch their dispersed and aggregated state in the presence of the target. This state of change can modulate the spin-spin relaxation time (T₂) of the neighboring water molecule. The change in T₂(ΔT₂) positively correlates with the amount of the target in the sample. Thus, AT can be used as a detection signal in MRS immunosensors. Results showed that LOD of MRS sensor for S. enterica was 10³ cfu · mL⁻¹ and analysis time was 0.5 h. Two methods were compared in terms of advantages and disadvantages in detecting S. enterica.

A fluoroimmunoassay based on quantum dots (QDs) and a lateral flow immunoassay system based on the magnetic beads (MB) were constructed to detect ractopamine (RAG) in urine samples. The monoclonal antibody (Ab1) against RAC was conjugated with QDs or MB as detector reagent, respectively. They apply a competitive format using an immobilized RAC conjugate and free RAC present in samples. That is to say, the concentration of RAC in the sample was negative related to the fluorescense intensity of QDs or the color density of MB. Results showed that the limit of detection (LOD) of fluorescence immunoassay method is 1 ng · mL⁻¹ and analysis time is 4 h, while the visual LOD was 10 ng · mL⁻¹ and analysis time was 15 min in magnetic lateral flow immunoassay system (MFLIS). Taken into consideration of the advantages and disadvantages of the two methods, it was suitable for the trace detection of RAC using fluoroimmunoassay while it was appropriate for point-of-care tesing of RAC by MFLIS.

P-toluenesulfonic acid (TSA) doped polypyrrole (PPy) binary nanocomposite and MnO2/PPy/TSA ternary nanocomposite were prepared by chemical oxidative polymerization. The chemical compositions of nanocomposites were characterised by infrared spectrometry and energy dispersive spectroscopy. Micrographs and BET isotherm measurements showed that the particle and the pore size of the ternary nanocomposite are much smaller than those of the binary one. Electrochemical measurements showed that the ternary nanocomposite electrode exhibited a higher specific capacitance of ∼376 F g−1 at 3 mA cm−2 and better cycling stability in 0.5 M Na2SO4 solution than the binary one, which is attributed to that the dispersed MnO2 particles adhered to PPy chains increase the specific surface area of the ternary nanocomposite and retard the structural deterioration of PPy backbones during charge–discharge cycling process. Long cyclic measurements showed that the specific capacitance of ternary composite can retain 90% of its initial value over 500 charge–discharge cycles in the potential range of −0.1 to 0.9 V vs. SCE. Nevertheless, the dispersed MnO2 could reduce the rate capability and conductivity of the ternary composite.

Three-bending experiments were performed on RC beams strengthened with prestressed CFRP under static and cycle loading. Prestressed CFRP obviously increases the load-carrying capacity and fatigue life of strengthened RC beam. And it greatly increases the flexural stiffness of strengthened beam. The failure modes of the beams go through concrete cracking, CFRP debonding from concrete and beam fractured. The vertical flexibility history at midspan is decomposed into three stages. And then fatigue damage is defined by flexural stiffness and its evolvement shows three stages of nucleation, growth and mutation.

Soybean (Glycine max L. Merr.) is the world's foremost source of edible plant oil and proteins, meantime, the biologically active secondary metabolites such as saponins and isoflavones are benefit to human health. The objective of this study was to identify quantitative trait loci (QTL) and epistatic interactions associated with isoflavone, protein, and oil contents in soybean seeds. An F13 recombinant inbred line (RIL) comprising 474 lines was derived from a cross between Jindou 23 and Huibuzhi cultivars. SSR technique was employed for mapping of the QTLs. The QTLs for isoflavone, protein, and oil contents were analyzed and 23 QTLs were detected based on the constructed linkage map. Six QTLs for isoflavone content were localized in linkage groups J, N, D2, and G, eleven QTLs for oil content were localized in the linkage groups Al, A2, B2, C2, and D2, and six QTLs for protein content were localized in linkage groups B2, C2, G, and H1. The correlative analysis demonstrated that the isoflavone content had significant correlation with protein content, while significantly negative correlations was existed between oil and protein content, and significantly positive correlations was existed between protein and oil content. All these findings have laid an important basis for the marker assisted breeding in soybean. The phenotypic correlations of quantitative traits may be resulted from the correlation of the QTL controlling those traits.

To examine the distribution patterns of organic contaminants in rapidly urbanizing regions, the levels and spatial distributions of 19 overlooked insecticides, i. e., phenyl-pyrazole class (fipronil), chlordane, endosulfan, nonachlor, hexachlorobenzene, heptachlor, dieldrin, aldrin, endrin, methoxychlor and their metabolites, were examined in 229 soil samples collected from the Pearl River Delta (PRD) and surrounding areas. The results indicated that higher insecticide levels distributed in the central PRD, while lower levels congested in the surrounding areas. The similar spatial patterns between the levels of insecticides and economic prosperity or population density demonstrated that social-economic factors may have dictated the spatial patterns of insecticides. In addition, the changing of land-use types during urbanization processes, e.g., historical plowlands have been converted into residential landscapes, resulted in high concentrations of banned insecticides in metropolis of the central PRD. Source diagnostics indicated that new inputs of technical chlordane products existed in the PRD and surrounding areas. Fipronil was degraded into fipronil sulfone and fipronil sulfide in most soil samples because of its low half-life in soil. Finally, a risk assessment of 19 insecticides in soil for human health suggested that six samples collected from the major administrative districts with dense population had potential cancer or non-cancer risk to human health. Therefore, these overlooked insecticides should be concerned in future environmental research.

The interaction between 3,3-bis(4-hydroxy-1-naphthyl)-phthalide (NPP) and bovine serum albumin (BSA) have been studied by fluorescence spectroscopy. The binding of NPP quenches the BSA fluorescence. By the fluorescence quenching results, it was found that the binding constant K = 5.30 × 10 4 L mol −1 , and number of binding sites n = 0.9267. In addition, according to the synchronous fluorescence spectra of BSA, the results showed that the fluorescence spectra of BSA mainly originate from the tryptophan residues. Finally, the distance between the acceptor NPP and BSA was estimated to be 1.94 nm using Foster's equation on the basis of fluorescence energy transfer. The interaction between NPP and BSA has been verified as consistent with the static quenching procedure and the quenching mechanism is related to the energy transfer.

A simple and promising H2O2 biosensor has been developed by successful entrapment of horseradish peroxidase (HRP) in a gelatine matrix which was cross-linked with formaldehyde. The large microscopic surface area and porous morphology of the gelatine matrix lead to high enzyme loading and the enzyme entrapped in this matrix can retain its bioactivity. This biosensor exhibited a fast amperometric response to hydrogen peroxide (H2O2). The linear range for H2O2 determination was from 2.5×10 -5 to 2.5×10 -3 M, with a detection limit of 2.0×10 -6 M based on S / N = 3. This biosensor possessed very good reproducibility.

We aimed at investigating the role of CYP2C9 in carvedilol O-desmethylation and identifying the effect of 35 CYP2C9 allelic variants we found in Chinese Han population on the in vitro metabolism of carvedilol. Recombinant CYP2C9 and CYP2D6 microsomes of the wild type were used to test and verify the enzymes involved in carvedilol O-desmethylation. Recombinant CYP2C9 microsomes of distinguished genotypes were used to characterize the corresponding enzyme activity toward carvedilol. 2–100 μM carvedilol was incubated for 30 min at 37 °C. The products were detected using high-performance liquid chromatography. CYP2C9 plays a certain role in carvedilol metabolism. Compared with wild-type CYP2C9*1, the intrinsic clearance (V max/K m) values of all variants toward carvedilol O-desmethylation were significantly altered. The variants exhibited significantly decreased values (from 30 to 99.8 %) due to increased K m and/or decreased V max values. We conclude that recombinant system could be used to investigate the enzymes involved in drug metabolism and these findings complement the database where CYP2C9 polymorphism interacts with biotransformation of exogenous substances like drugs and toxins.

The jujube (Ziziphus jujuba Mill.), a member of family Rhamnaceae, is a major dry fruit and a traditional herbal medicine for more than one billion people. Here we present a high-quality sequence for the complex jujube genome, the first genome sequence of Rhamnaceae, using an integrated strategy. The final assembly spans 437.65 Mb (98.6% of the estimated) with 321.45 Mb anchored to the 12 pseudo-chromosomes and contains 32,808 genes. The jujube genome has undergone frequent inter-chromosome fusions and segmental duplications, but no recent whole-genome duplication. Further analyses of the jujube-specific genes and transcriptome data from 15 tissues reveal the molecular mechanisms underlying some specific properties of the jujube. Its high vitamin C content can be attributed to a unique high level expression of genes involved in both biosynthesis and regeneration. Our study provides insights into jujube-specific biology and valuable genomic resources for the improvement of Rhamnaceae plants and other fruit trees., The jujube is a major dry fruit crop in China and is commonly used for medicinal purposes. Here the authors sequence the genome and transcriptome of the most widely cultivated jujube cultivar, Dongzao, and highlight the genetic and molecular basis of agronomically important jujube traits, such as vitamin C content.

Available literature data on five typical groups of emerging contaminants (EMCs), i.e., chlorinated paraffins (CPs), dechlorane plus and related compounds (DPs), hexabromocyclododecanes (HBCDs), phthalate esters, and pyrethroids, accumulated between 2003 and 2013 were assimilated. Research efforts were categorized by environmental compartments and countries, so that global trends of research on EMCs and data gaps can be identified. The number of articles on the target EMCs ranged from 126 to 1,379 between 2003 and 2013. The numbers of articles on CPs, DPs, HBCDs, and pyrethroids largely followed the sequence of biota > sediment ≥ air > water ≥ soil > human tissue, whereas the sequence for phthalate esters was water > sediment > soil > human tissue ≥ biota ≥ air. Comprehensive studies on the target EMCs in biological samples and human tissues have been conducted worldwide. However, investigations into the occurrence of the target EMCs in soil of background areas and water are still scarce. Finally, developed and moderately developed countries, such as the USA, China, Canada, Japan, and Germany, were the main contributors to the global research efforts on EMCs, suggesting that economic prosperity may be one of the main factors propelling scientific research on EMCs.

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in soil of the Pearl River Delta (PRD) and surrounding areas was examined on a basis of six land-use types and four geographic regions, from which the impacts of anthropogenic events on the terrestrial environment were evaluated. No significant difference in the concentrations of Σ28PAH and Σ15PAH (sums of 28 and 15 PAHs, respectively) was found among the land-use types of industry, landfill and residency. On the other hand, higher soil PAH concentrations occurred in the central PRD characterized by dense population and high urbanization level, compared to other geographic regions. Source diagnostics implicated the combustions of coal and refined petroleum as the major input sources of anthropogenic PAHs. Furthermore, low molecular weight PAHs tended to volatilize from soil to air while the opposite was prevailing for high molecular weight PAHs. The mean annual diffusive flux of Σ15PAH (852 μg m− 2 yr− 1) from the soil to the atmosphere in the central PRD was greater than those in the PRD's periphery (195 μg m− 2 yr− 1), West region (322 μg m− 2 yr− 1) and East region (84.9 μg m− 2 yr− 1), suggesting that the central PRD may have become a secondary source of PAHs to the surrounding areas. Finally, ecological risk assessment based on the classification from Maliszewska-Kordybach showed that 3.5% of soil within the central PRD was heavily contaminated by PAHs and 5.2 million residents may be subjected to high health risk.

The present article studied the interaction between intramolecular charge transfer fluorescence probe-1-keto-2-(p-dimethylaminobenzal)-tetrohydronaphthalene (KDTN) and bovine serum albumins (BSA). With the concentration of KDTN increasing, the fluorescence of BSA rapidly quenched and the fluorescence peak gradually blue-shifted. The result indicated that they were bound mainly by hydrophobic interaction. The binding sites is 0.94 (3 degrees C) and the equilibrium constant K is 3.27 x 10(4) L x mol(-1). Temperature increment is advantageous to the combination. It is a single static quenching process that the fluorescence of BSA quenches, which is induced by the combination of KDTN and BSA. Further study showed that different substances had different effects on the combination of KDTN and BSA.

The interation of caffeine and theophylline with bovine serum albumins has been studied by fluorescence spectroscopy. The results indicated that enoxacin could bind with BSA strongly at molar ratio 1:1 and the equilibrium constants were Kc = 1.673 x 10(4) L x mol(-1) and Kt = 6.802 x 10(3) L x mol(-1), respectively. Good linear Stern-Volmer lines were observed on the fluorescence of BSA quenched by enoxacin of different concentration, indicating that the combination reaction of enoxacin with BSA is a single static quenching process.