On-site monitoring and numerical simulation on groundwater flow and pollution plume evolution in a hexavalent-chromium contaminated site.

Accurately ascertaining spatiotemporal distribution of pollution plume is critical for evaluating the effectiveness of remediation technologies and environmental risks associated with contaminated sites. This study concentrated on a typical Cr(VI) contaminated smelter being currently remediated using pump-and-treat (PAT) technology. Long-term on-site monitoring data revealed that two highly polluted regions with Cr(VI) concentrations of 162.

Contaminant back-diffusion from layered aquitards subjected to barrier-controlled source zones.

Low-permeability aquitards may serve as secondary sources of slow-releasing contaminants into the adjacent aquifer system, creating considerable obstacles to groundwater cleanup. Accurately capturing the exchange of contaminant mass between aquitards and aquifers can facilitate site management and remediation. Previous simulation studies were mainly limited to one-dimensional (1D) back diffusion from aquitards during the remediation of the source zone.

Forward and back diffusion of reactive contaminants through multi-layer low permeability sediments.

Contaminants stored in the low permeability sediments will continue to threaten the adjacent shallow groundwater system after the aquifer is remediated. Understanding the storage and discharge behavior of contaminants in the aquitards is essential for the efficient remediation of contaminated sites, but most of the previous analytical studies focused on nonreactive solutes in a single homogenous aquitard. This study presents novel analytical solutions for the forward and back diffusion of contaminants through multi-layer low permeability sediments considering abiotic and biotic environmental degradation.

Investigating the roles of advection and degradation in chlorinated solvent back-diffusion from multi-layer aquitards: A novel analytical approach.

Aquitards contaminated by chlorinated solvents may act as a secondary source slowly releasing contaminants into adjacent aquifers, thus severely hampering the remediation of groundwater systems. Accurate predicting the long-term exchange of solvents between aquifers and aquitards can more effectively guide site management and remediation. This study presented a general analytical model for the back-diffusion of chlorinated solvents through multilayer aquitards.

Approximate analytical model for transient transport and oxygen-limited biodegradation of vapor-phase petroleum hydrocarbon compound in soil.

Volatile organic compounds (VOCs) contamination may occur in subsurface soil due to various reasons and pose great threat to people. Petroleum hydrocarbon compound (PHC) is a typical kind of VOC, which can readily biodegrade in an aerobic environment. The biodegradation of vapor-phase PHC in the vadose zone consumes oxygen in the soil, which leads to the change in aerobic and anaerobic zones but has not been studied by the existing analytical models.

Two-dimensional analytical solution for subsurface volatile organic compounds vapor diffusion from a point source in layered unsaturated zone.

Although migration of subsurface volatile organic compounds (VOCs) from contaminant sources in unsaturated soil widely exists, the related analytical models are quite limited. A two-dimensional analytical solution is hence developed to simulate vapor diffusion from the subsurface contaminant source in the layered unsaturated zone. The contaminant source is simplified as a point source leaking at a constant rate.

Transient migration behavior of VOC vapor in layered unsaturated soils subjected to multiple time-dependent point pollution sources: Analytical study.

Predicting the migration behavior of volatile organic compounds (VOCs) vapor is essential for the remediation of subsurface contamination such as soil vapor extraction. Previous analytical prediction models of VOCs migration are mostly limited to constant-concentration nonpoint sources in homogeneous soil. Thus, this study presents a novel analytical model for two-dimensional transport of VOCs vapor subjected to multiple time-dependent point sources involving transient diffusion, sorption and degradation in layered unsaturated soils.

An analytical model for one-dimensional diffusion of degradable contaminant through a composite geomembrane cut-off wall.

A one-dimensional analytical model is proposed to analyze contaminant diffusion through a composite geomembrane cut-off wall (CGCW) composed of a geomembrane (GMB) and a bentonite cut-off wall (BCW). The model considers degradation process of contaminant and time-dependent inlet boundary condition which are common in engineering practices. Moreover, two limiting scenarios of the exit boundary condition (EBC) of CGCW for field conditions are taken into account, including the flushing and non-advective semi-infinite aquifer EBCs.

miR-375 and miR-30d in the effect of chromium-containing Chinese medicine moderating glucose metabolism.

In China, TianMai Xiaoke tablet (TM) is used to treat type 2 diabetes. However, the exact mechanism of TM is not clear. This study is to investigate the effect of TM on glucose metabolism in diabetic rats and to identify whether TM takes a direct action through microRNAs on islet.

α-Internexin: a novel biomarker for pancreatic neuroendocrine tumor aggressiveness.

Purpose: We aimed to test whether α-internexin could be a molecular biomarker of tumor aggressiveness and prognosis in pancreatic neuroendocrine tumors (PNETs).

Patients And Methods: Using immunohistochemical staining and Western blot, we detected the expression of α-internexin in 350 tumors from 343 patients, of whom 257 were followed up. Methylation of α-internexin promoter was examined by bisulfite sequencing to identify the crucial region that determines gene expression.

Prevalence and risk factors of diabetes in patients with Klinefelter syndrome: a longitudinal observational study.

Objective: To evaluate the prevalence and risk factors of diabetes in patients with Klinefelter syndrome.

Design: Retrospective longitudinal study.

Setting: Medical college hospital.

Effects of variation in retinol binding protein 4 gene and adipose specific expression of gestational diabetes in Beijing, China.

Objective: To investigate the clinical features of GDM in China and the effects of RBP4 genetic variants, and also to identify RBP4 expression changes in mRNA and protein levels.

Research Design And Methods: 1595 Chinese pregnant women were included in this study. Four known RBP4 single nucleotide polymorphisms (SNPs) were genotyped in 505 cases and 687 controls.

[Changes of insulin resistance and islet beta cells function in subjects with high-normal blood pressure].

Objective: To investigate the changes of insulin resistance and islet beta cells function in subjects with euglycemia and high-normal blood pressure.

Methods: Total 423 subjects were divided into normal blood pressure group and high-normal blood pressure group. Body height, weight, waist and hip circumference, and biochemical data were measured.

Clinical implications of microsatellite instability and MLH1 gene inactivation in sporadic insulinomas.

Context: The molecular pathogenesis of sporadic insulinomas is unknown. There is a lack of biomarker to distinguish benign and malignant form of insulinoma.

Objective: Our objective was to confirm the occurrence of microsatellite instability (MSI) in insulinomas, to identify alterations of mismatch repair (MMR) genes in the tumors, and to evaluate the possibility to distinguish benign and malignant insulinoma or to predict the clinical outcome of patients with these alterations.

Identification of a regulatory single nucleotide polymorphism in the adiponectin (APM1) gene associated with type 2 diabetes in Han nationality.

Objective: To identify the genetic defects of the the adiponectin (APM1) gene that contribute to the development of type 2 diabetes (T2DM) and determine the functional single nucleotide polymorphisms (SNPs) in the APM1 gene associated with T2DM in Han nationality.

Methods: The APM1 gene 5'-UTR was screened by direct sequencing to identify common polymorphisms. Identified SNPs were genotyped in 585 nondiabetic controls, 278 subjects with impaired glucose intolerance (IGT) and 212 patients with T2DM.

Association of ghrelin polymorphisms with metabolic syndrome in Han Nationality Chinese.

Objective: To investigate the association of ghrelin gene polymorphisms with metabolic syndrome in Han Nationality Chinese.

Methods: A total of 240 patients with metabolic syndrome and 427 adults aged above forty years were recruited. Genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism analysis.

[Study on diabetes prevalence in urban China].

Objective: To describe the status of diabetic mellitus (DM) prevalence and fast blood glucose level among urban population in China.

Methods: All 16 511 subjects, from households participating in dietary survey, aged over 20 years, were randomly sampled from 44 urban sites in 31 provinces, autonomous regions and municipalities. The diagnosis of DM was based mainly on fast plasma glucose concentration, combining with oral glucose tolerance test and the survey of previous diabetic mellitus diagnosis in local hospitals.

Association of angiotensin converting enzyme gene I/D polymorphism with type 2 diabetes mellitus.

Objective: To investigate the association of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with type 2 diabetes mellitus (T2DM).

Methods: Two hundred and nine patients with T2DM diagnosed based on the criteria for diabetes mellitus in 1999 by WHO and 221 controls were recruited from general population of Dongcheng District in Beijing. All subjects were genotyped for the I/D polymorphism of ACE gene by PCR-fragment length polymorphism (FLP) assay.

[A description on the Chinese national nutrition and health survey in 2002].

Objective: To describe the status of nutrition and health related indices in the Chinese population.

Methods: A stratified multi-stage cluster sampling was used from 31 provinces, autonomous regions, and municipalities. The survey was done in 2002, including data gathered from questionnaires, interviews, physical examinations, measurement of biochemical indices, and dietary investigation.

[Leptin and clustering of the components of risk factors for metabolic syndrome].

Objectives: To evaluate relationship between serum level of leptin and the components of risk factors for metabolic syndrome and to analyze the characteristics and laws of clustering of the risk factors.

Methods: Totally, 795 non-diabetic adult Chinese subjects (691 men and 104 women, aged 40 - 75 years) from a diabetes prevalence survey in 2000 were involved in this study. Measurements included serum levels of true insulin (TI), leptin, fasting lipids, fasting glucose (FBG) and 2 h postchallenge glucose, as well as seated blood pressure (BP), body mass index (BMI), ratio of waist circumference to hip circumference (WHR), calculated quantitative insulin sensitivity check index (QUICKI), etc.

[Study on prevalence rates of hypertension and chronic diabetic complications of in-patients with diabetes].

Objective: To understand the relationship between prevalence rates of chronic diabetic complications and related macro-vascular diseases and hypertension, to provide evidence for diabetes prevention and control.

Methods: To retrospectively analyze the clinical and laboratory data on 24 496 in-patients with diabetes during Jan. 1, 1991 to Dec.

[Epidemiological survey of chronic vascular complications of type 2 diabetic in-patients in four municipalities].

Objective: To provide an epidemiological description and risk factors of chronic vascular complications of type 2 diabetic in-patients in four municipalities including Beijing, Shanghai, Tianjin, and Chongqing.

Methods: Data of the study came from 3,469 Type 2 diabetic in-patients from 1991 to 2000 in 10 medical centers of Beijing, Shanghai, Tianjin, and Chongqing. A variety of parameters of in-patients were evaluated retrospectively to know the prevalence and risk factors of chronic vascular complications in the study patients.