Formation and evolution of the Changbaishan volcanic geothermal system in a convergent plate boundary back-arc region constrained by boron isotope and gas data
JOURNAL OF HYDROLOGY
Authors: Zhao, Rongsheng; Shan, Xuanlong; Wu, Chengzhi; Yi, Jian; Hao, Guoli; Wang, Pujun
Abstract
The goal of this study is to analyze fluid geochemistry, boron isotope and gas data to reassess the formation and evolution processes of the Changbaishan volcanic geothermal system (Jilin, China). Due to the presence of hot fumaroles (with temperatures of higher than 100 degrees C) and sinters, we believe that phase separation is occurring underground, which is also indicated by the characteristics of the B and gas data. Based on their hydrochemical data and B/Cl ratios, the thermal water samples in this area can be divided into three groups: 1) group 1 is steamheated/condensate water (group 1-1: JJ, JLQ; group 1-2: SBDG, XRQ); 2) group 2 is karst water (CR3 and LSD); and 3) group 3 is residual water (CR1 and CR2). The preliminary discrimination of samples using B and gas data implies that group 1-1 around the crater is controlled by a second phase separation process, which is induced by the input of hot magmatic material; group 1.2 in the basin area is controlled by the transformation of clay minerals, and the XRQ water sample shows contamination by sewage; group 2 represents karst water that has leached metamorphic rock and been directly heated by the input of hot magmatic volatiles; and group 3 is the result of one seawater phase separation process. The mixing and fluid-rock interaction models based on the mass balance of boron concentration and isotope imply that the phase separation and input of magmatic volatiles are more important than fluid-rock interactions in the formation of the Changbaishan geothermal system, and the first phase separation process in the deep carbonate reservoir occurred in a late stage, with approximately 75%-87.5% of water becoming vapor. Additionally, the Rayleigh distillation of B isotope implies that new magma is being generated below this area, with the low B concentrations and high boron isotopic values of its gases implying that the mixed component may be derived from the subducted Pacific plate (e.g., marine sediment). The addition of "excess heat" due to the continued subduction of the Pacific plate has further encouraged the phase separation process, and the subduction process has also accelerated the transition of the hydrothermal system into a non-hydrothermal system.
Association Between Genetic Polymorphisms ofCR2Gene and the Risk of Steroid-Induced Osteonecrosis of the Femoral Head in the Chinese Han Male Population
GENETIC TESTING AND MOLECULAR BIOMARKERS
Authors: Zhao, Zandong; Zhang, Liang; Kang, Xin; Zheng, Jiang; Tian, Bin
Abstract
Background:Multiple lines of evidence have suggested that genetic factors may contribute to steroid-induced osteonecrosis of the femoral head (SONFH). Complement receptor 2 (CR2), constituting a family of regulators of complement activation, has been recently reported to be associated with osteonecrosis of the femoral head (ONFH) in Koreans. The aim of this study was to evaluate the relationships between theCR2gene and susceptibility to SONFH in the male Han Chinese population. Materials and Methods:A total of 468 SONFH patients and 1224 healthy controls were recruited to the study. Ten tag single nucleotide polymorphisms (SNPs) located within theCR2gene were genotyped. Genetic association analyses, including SNP and haplotypic analyses, were performed for the 10 SNPs. Furthermore, bioinformatic analyses were conducted to examine the functional consequences of significant SNPs. Results:An intronic SNP, rs311306, was identified to be significantly associated with the risk of SONFH (p = 0.0008, odds ratio = 1.44). Allelic analyses showed that the C allele of this SNP significantly elevated the risk of SONFH, which was replicated in genotypic association analyses. Moreover, a 3-SNP haplotype was significantly associated with SONFH (rs311306-rs17044576-rs3767933,p = 7.49 x 10(-8)). Furthermore, bioinformatic analysis results indicated limited functional consequences of SNP rs311306, but a complex interaction network was constructed by the protein encoded by theSLC44A2gene and proteins encoded byCD19,CD81, andC3genes. Conclusion:Our findings shed new light on the link between theCR2gene and SONFH in Han Chinese males, providing clues as to the nature of the mechanisms involved in the etiology of ONFH.