[The Breast Cancer Cohort Study in Chinese Women: the construction and progress of the pan-shared biobank].

Objective: Biobank construction plays an irreplaceable role in the research of accurate prevention and treatment of diseases. Shared biobank network based on a large crowd queue is the way of the future. This subject is one of the key contents of national precision medicine "The Breast Cancer Cohort Study in Chinese Women: (BCCS-CW)" , aiming to solve the bottleneck of insufficient standardization and sharing. Methods: The establishment of "entity library-information library-extension library" , the widely Shared network of biobank of breast cancer specific disease cohort, and the establishment of strict standard setting and quality control standard to construct the standardized biobank. Results: This biobank provides a shared biobank resource for breast cancer risk assessment, prediction and early warning, early screening, classification, individualized treatment, efficacy and safety prediction and monitoring and other accurate prevention and treatment programs and clinical decision-making system research. Conclusion: The data of this biological sample bank is refined and complete, and the sample size of cases is sufficient, which can meet the research needs of medical big data, genomics, metabonomics, epigenetics and other fields.

Bibliometric Analysis of Research Hotspots Related to Marine Oil Spill Accidents in the Environmental Field Based on Web of Science.

ABSTRACT: Objective To conduct bibliometric analysis of the relevant literature in the environmental field published from 1982 to 2018 collected by the Web of Science citation database and further explore the frontier research dynamics and hotspots in the environmental field. Methods The word "oil spill*" was used as the subject term for retrieval. A knowledge map of hotspots in oil spill research was built through software VOSviewer and the clustering relations between them were explored. The frequency and relevance of the keywords in the corresponding literature were obtained by the matrix of keywords built through the Thomson Data Analyzer （TDA） software. Results The four main research hotspots of marine oil spill pollution were oil spill numerical simulation and model prediction, oil spill exposure toxicity and risk assessment, oil spill component and source analysis and oil spill pollution characteristics and treatment. Conclusion The study analyzes the main content of the four research hotspots and the current research progress and provides scientific basis for further understanding of the mechanism of marine oil spill occurrence, migration and transformation, implementation of oil spill treatment and repair as well as more accurate assessment of eco-environment damage.

Multimedia model of atrazine in plant-soil-groundwater system with a fugacity approach.

The application of atrazine in China during the last ten years has led to some environmental problems. In this paper, the multimedia model of atrazine in soil-plant-groundwater system at Baiyangdian Lake area in Northern China was established using a fugacity approach, and verified with observed values. The model involved 7 environmental compartments which are air, groundwater, soil, corn roots, corn stem, corn leaf and kernel of corn. The results showed that the relative errors between calculated and observed values have a mean value of 24.7%, the highest value is 48% and the lowest value is 1.4%. All these values indicated that this multimedia model can be used to simulate the environmental fate of atrazine. Both the calculated and observed values of concentrations of atrazine in plant compartments are in the following order: in corn roots > in corn stem > in kernel of corn > in corn leaf, it exhibited a good regularity. The prediction results indicated that concentrations of atrazine in the groundwater and kernel of corn will override the limitation of 3 micrograms/L and 0.05 mg/kg respectively.

Hydrolysis kinetics of atrazine and influence factors.

The hydrolysis kinetics of atrazine in distilled water and leaching water from soil, and their influence factors were studied by incubation at 35 degrees C and HPLC analysis method. The kinetic process of atrazine hydrolysis can be described by the first-order reaction law. The results showed that the hydrolysis rate constants k in leaching water and distilled water were 1.606 x 10(-3)/d and 1.055 x 10(-3)/d, respectively; the half-life of atrazine hydrolysis in distilled water at pH 3, pH 4.5 and pH 8 were 373 days, 522 days and 657 days respectively. The results also showed that the proton in reaction solution can catalyze the atrazine hydrolysis; humic acid and NH4+ etc. substances in aqueous solution can facilitate atrazine hydrolysis; rate constants of atrazine hydrolysis with humic acid and NH4NO3 were 2.431 x 10(-3)/d and 1.498 x 10(-3)/d respectively which were 2.3 and 1.42 times of control (1.055 x 10(-3)/d); anion NO3- can inhibit catalysis of humic acid to atrazine hydrolysis.

Distribution of atrazine in a crop-soil-groundwater system at Baiyangdian Lake area in China.

In this paper, the concentration distribution and environmental fate of atrazine in a crop-soil-groundwater system at Baiyangdian Lake area of North China were studied. The concentration of the herbicide in spatial and vertical soils, and in roots, stem, leaf, corncob and kernel of corn, and in groundwater were measured by HPLC. The results showed that the variation of spatial concentration of atrazine in soil can be described by first-order kinetics equation which has a half-life of 360 days and a rate constant of 0.0019 d-1. The vertical variation of atrazine concentration with soil depth follows the exponential decay law. After 120 days following atrazine application, the mass distributions of this herbicide in crop-soil-groundwater system are 71% in soil, 20% in groundwater and 1% in crop respectively, and 8% due to loss by degradation or often removal processes. The order of atrazine concentration in every part of corn crop is in roots > in corncob > in kernel of corn > in leaf.

Identification of UV photoproducts and hydrolysis products of butachlor by mass spectrometry.

The photoproducts and hydrolysis products of butachlor in water were identified by gas chromatography/mass spectrometry. When exposed to UV light, butachlor in aqueous solution was rapidly degraded, giving at least 11 photoproducts as a result of dechlorination with subsequent hydroxylation or cyclization processes. The chemical structures of nine degradation compounds were identified on the basis of mass spectrum interpretation and literature data. Major photoproducts are identified as 8-ethyl-1-butoxymethyl-4-methyl-2-oxo-1,2,3,4-tetrahydro-quinoline, 2-hydroxy-2',6'-diethyl-N-(butoxymethyl) acetanilide, and a compound related to butachlor. Minor photoproducts are identified as 2,6-diethylaniline; 1-acetyl-7-ethylindole; N-(2,6-diethylphenyl)-N-(butoxymethyl)acetamide; 2-oxo-N-(2,6-diethyl-phenyl)-N-(butoxymethyl)acetamide; 1-hydroxyacetyl-2-butoxyl-3-methyl-7-ethylindole; 1-acetyl-2-butoxyl-3-methyl-7-ethylindole; and two compounds with the chemical structure unknown. The half-lives of butachlor UV photolysis were 7.54, 10.56, and 12.22 min in deionized water, river water, and paddy water, respectively. The half-lives of butachlor hydrolysis at pH 4, 7, and 10 were 630, 1155, and 1155 days at 25 +/- 1 degrees C, respectively. A hydrolysis product at pH 4 was identified by GC/MS to be 2-hydroxy-2',6'-diethyl-N-(butoxymethyl) acetanilide.