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BACKGROUND: Potential modification of the association between maternal particulate matter (PM) exposure and preterm delivery (PTD) by folic acid (FA) supplementation has not been studied. OBJECTIVE: We examined whether FA supplementation could reduce the risk of PTD associated with maternal exposure to PM in ambient air during pregnancy. METHOD: In a cohort study covering 30 of the 31 provinces of mainland China in 2014, 1,229,556 primiparas of Han ethnicity were followed until labor. We collected information on their FA supplementation and pregnancy outcomes and estimated each participant's exposure to PM with diameters of =10µm (PM10), 2.5µm (PM2.5), and 1µm (PM1) using satellite remote-sensing based models. Cox proportional hazard regression models were used to examine interactions between FA supplementation and PM exposures, after controlling for individual characteristics. RESULTS: Participants who initiated FA =3?months prior to pregnancy (38.1%) had a 23% [hazard ratio (HR)=0.77 (95% CI: 0.76, 0.78)] lower risk of PTD than women who did not use preconception FA. Participants with PM concentrations in the highest quartile had a higher risk of PTD [HR=1.29 (95% CI: 1.26, 1.32) for PM1, 1.52 (95% CI: 1.46, 1.58) for PM2.5, and 1.22 (95% CI: 1.17, 1.27) for PM10] than those with exposures in the lowest PM quartiles. Estimated associations with a 10-µg/m³ increase in PM1 and PM2.5 were significantly lower among women who initiated FA =3?months prior to pregnancy [HR=1.09 (95% CI: 1.08, 1.10) for both exposures] than among women who did not use preconception FA [HR=1.12 (95% CI: 1.11, 1.13) for both exposures; ?interaction<0.001]. The corresponding association was also significantly lower for a 10-µg/m³ increase in PM10 [HR=1.03 (95% CI: 1.02, 1.03) for FA =3?months before pregnancy vs. 1.04 (95% CI: 1.03, 1.04) for no preconception FA; ?interaction<0.001]. CONCLUSION: Our findings require confirmation in other populations, but they suggest that initiating FA supplementation =3?months prior to pregnancy may lessen the risk of PTD associated with PM exposure during pregnancy among primiparas of Han ethnicity. [ABSTRACT FROM AUTHOR]

We aimed to clarify the epidemiologic and clinical importance of evolutionary events that occurred in carbapenem-resistant Klebsiella pneumoniae (CRKP). We collected 203 CRKP causing bloodstream infections in a tertiary hospital in China during 2013-2017. We detected a subclonal shift in the dominant clone sequence type (ST) 11 CRKP in which the previously prevalent capsular loci (KL) 47 had been replaced by KL64 since 2016. Patients infected with ST11-KL64 CRKP had a significantly higher 30-day mortality rate than other CRKP-infected patients. Enhanced virulence was further evidenced by phenotypic tests. Phylogenetic reconstruction demonstrated that ST11-KL64 is derived from an ST11-KL47-like ancestor through recombination. We identified a pLVPK-like virulence plasmid carrying rmpA and peg-344 in ST11-KL64 exclusively from 2016 onward. The pLVPK-like-positive ST11-KL64 isolates exhibited enhanced environmental survival. Retrospective screening of a national collection identified ST11-KL64 in multiple regions. Targeted surveillance of this high-risk CRKP clone is urgently needed. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the population structure, drug resistance mechanisms and plasmids of community-associated Enterobacter cloacae complex (CA-ECC) isolates in China.Methods: Sixty-two CA-ECC isolates collected from 31 hospitals across China were typed by hsp60 typing and MLST. ESBL and AmpC-overexpression phenotype was determined by double-disc synergy test. Replicon typing and conjugation were performed for plasmid analysis. All ESBL-positive isolates and representative conjugants were subjected to detailed characterization by WGS.Results: Enterobacter hormaechei and Enterobacter kobei were predominant in our collections. MLST distinguished 46 STs with a polyclonal structure. ST591 was the most prevalent clone detected in northern China. Twenty-two isolates (35.5%) were ESBL positive and half of them were E. kobei. ESBL positivity was related to ESBL production (15/22) and to AmpC overexpression (18/22). Core-genome phylogenetic analysis identified intra- and inter-regional dissemination of ESBL-producing E. kobei clones. ESBL producers were exclusively classified as E. hormaechei and E. kobei, and blaCTX-M-3 was the most prevalent ESBL genotype (10/15) detected in four different environments. In the ESBL-positive population, the ESBL producers encoded more drug resistance genes (8-24 genes) by carrying more plasmids (1-3 plasmids) than the non-ESBL-producing isolates, resulting in an inter-group difference in drug susceptibilities. IncHI-type plasmids were prevalent in the ESBL producers (12/15). All IncHI2-type plasmids (n = 11) carried ESBL genes and shared a similar backbone to p09-036813-1A_261 recovered from Salmonella enterica in Canada.Conclusions: The species-specific distribution, species-dependent ESBL mechanism and endemic plasmids identified in our study highlight the necessity for tailored surveillance of CA-ECC in the future. [ABSTRACT FROM AUTHOR]

The Shimensi deposit (Northern Jiangxi, South China) is a recently discovered super-large tungsten deposit. Muscovite 40Ar/39Ar dating yielded a plateau age of 145.7 ± 0.9 Ma, with normal and inverse isochronal ages being 145.4 ± 1.4 Ma and 145.3 ± 1.4 Ma, respectively. The muscovite 40Ar/39Ar age, which can represent the mineralization age, coincides well with the published zircon U-Pb ages (143-148 Ma) of the ore-hosting granites, which indicates that the tungsten mineralization was syn-magmatic. The new age reported here confirms that the Shimensi tungsten deposit is part of a large Early Cretaceous (147-136 Ma) tungsten-polymetallic belt in South China. Measured and calculated sulfur isotopic compositions (δ34Sminerals = -3.0% to 1.1%, average -1.3%; minerals34SH2S = -4.5h to +1.2h, average -1.8h) of the Shimensi ore-forming fluids indicate that the sulfur was mainly magmatic-derived. The calculated and measured oxygen and hydrogen isotopic compositions (218OH2O = 4.1h to 6.7%, δD = -62.7% to -68%) of the ore-forming fluids indicate a dominantly magmatic source with a meteoric water input. Oxygen isotopic modelling of the boiling/mixing processes indicates that the Shimensi tungsten mineralization was caused mainly by fluid mixing of magmatic hydrothermal fluid with meteoric water. [ABSTRACT FROM AUTHOR]

Previous studies have reported that XPC gene polymorphisms may modify the individual susceptibility to gastric cancer. In this case-control study with a total of 1,142 cases and 1,173 controls, four potentially functional polymorphisms were genotyped in the XPC gene (rs2228001 A>C, rs2228000 C>T, rs2607775 C>G, and rs1870134 G>C) by Taqman assays and their associations were analyzed with the risk of gastric cancer in a Southern Chinese population. No significant association between any of XPC polymorphisms and gastric cancer risk was detected except for a borderline association with the rs2228000 CT/TT genotype (crude odds ratio =0.86, 95% confidence interval =0.73-1.02, P=0.088) when compared to the rs2228000 CC genotype. Further stratified analysis revealed that the protective effect of rs2228000 CT/TT on the risk of gastric cancer was only significant among subjects older than 58 years. In summary, results indicated that genetic variations in XPC gene may play a weak effect on gastric cancer susceptibility in Southern Chinese population, which warrants further confirmation in larger prospective studies with different ethnic populations. [ABSTRACT FROM AUTHOR]

Objectives Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae has spread rapidly in China. In this study, we aimed to investigate the molecular epidemiology of KPC-producing K. pneumoniae isolates in China. Methods Ninety-five carbapenem-resistant K. pneumoniae isolates from 13 hospitals in nine cities covering five provinces in China were analysed. Antibiotic susceptibility was determined by the Etest. Multilocus sequence typing (MLST) and PFGE were used for epidemiological analysis. The genetic structure around blaKPC and the encoding genes of extended-spectrum β-lactamases and plasmid-mediated AmpC enzymes were detected by PCR and sequencing. Plasmids were analysed by transformation, restriction and Southern blot. Results All isolates harboured the blaKPC-2 gene. Seven sequence types (STs) were obtained. The dominant clone was ST11 (61/95), which was identified in isolates from Zhejiang province (four hospitals in Hangzhou and one hospital in Ningbo), Jiangsu province (one hospital in Nanjing) and Anhui province (one hospital in Hefei). Isolates with ST11 showed >80% similarity in PFGE patterns. Plasmids from 14 selected transformants, their original isolates representing different STs and/or regions, had a diversity of HindIII restriction maps. Conclusions The dominant clone of KPC-producing K. pneumoniae in China is ST11, which is closely related to ST258, which has been reported worldwide. [ABSTRACT FROM PUBLISHER]

Baogutu is the first porphyry Cu-Mo-Au deposit discovered in West Junggar, Xinjiang, China. It is part of the Central Asian orogenic belt. Baogutu is associated with a Carboniferous intrusive complex that was emplaced into lower Carboniferous volcano-sedimentary sequences of the Baogutu and Xibeikulasi Groups. The intrusive complex is made up of main stage equigranular to porphyritic diorites and quartz diorites, and minor late stage diorite porphyries. Intrusive activity occurred at about 325 Ma based on U-Pb (SHRIMP) analyses of zircons. The main stage diorites host the bulk of the Cu-Mo-Au mineralization at Baogutu. They have been over-printed by three alteration assemblages, including an early potassic (biotite) assemblage that occurs in the center of the deposit. A propylitic assemblage surrounds the potassic zone concentrically. Both of these alteration assemblages have been overprinted locally by phyllic alteration (quartz-sericite-pyrite), which is associated with the highest Cu-Mo grades. Mineralized and hydrothermally cemented breccias have disrupted the main stage diorites. The late stage diorites have undergone moderate potassic alteration and contain weak Cu mineralization. Matrix-rich breccias with very weak mineralization have cut the intrusive complex and disrupted the ore-body. Re-Os dating of molybdenite indicates that mineralization occurred at about 310 Ma. [ABSTRACT FROM AUTHOR]

Abstract  Integrated geological and geophysical investigations were carried out in 26 active mines in Northwestern China during the period 2001–2006 to explore for hidden extensions of known ore bodies and to search for new mineralization. This paper presents four case studies from northwest China: the Kuoerzhenkuoa volcanogenic hydrothermal gold deposit, the Nanjinshan breccia-associated gold deposit, the Duolanasayi deposit, associated with a ductile–shear zone, and the Hulu magmatic Cu–Ni sulfide deposit. In these studies, detailed mine-scale geological studies were carried out to determine the location and controls on ore formation. Based on these investigations and a review of previous exploration data, genetic models for the deposits were evaluated, and specific new targets were generated. These target areas were tested with surface geophysical surveys using the Stratagem EH4 system, a hybrid-source magnetotellurics (MT) method. Analysis of the data obtained in the surveys identified geophysical target anomalies that were subsequently drilled. Many of these test holes demonstrate the presence of Au and Cu–Ni mineralization. Evaluation of the geological models was crucial in developing conceptual targets as a basis for surface geophysical surveys. These models established the most likely target areas where Au and Cu–Ni mineralization could occur, but they did not define the limits or the geometries of the mineralized zones. Hybrid MT surveys played an important role in defining the location of buried mineralized systems and in testing the validity of the conceptual targets. The resistivity cross-sections obtained by imaging the MT data established the boundaries and geometries of the host rocks, including the distribution of lithology, structures, alteration, and mineralization. The four case studies in this paper show how this integrated geological and geophysical approach was used successfully to discover hidden mineral deposits. [ABSTRACT FROM AUTHOR]

The Kuoerzhenkuola gold deposit is located in the Sawur gold belt in Xinjiang, China. An integrated geological, geochemical and geophysical investigation was carried out in the Kuoerzhenkuola gold deposit, to determine the extension of the principal mineralized system, in the search for new resources. Re-examination of the rocks and structures in the Kuoerzhenkuola area showed that the study area features an elliptical caldera where the gold deposit lies. A re-investigation of the mine geology found that the mineralization at the Kuoerzhenkuola gold deposit is not controlled by the EW-striking regional fault as previously assumed, but by a caldera fracture system locally superimposed by regional faults; the host rocks are andesites and dacites of the Carboniferous Heishantou Group rather than the crypto-explosive breccia of the Devonian Sawurshan Group. Gas components of fluid inclusions from quartz, trace element chemistry of pyrite and fluid inclusions in pyrite, Pb isotopes of pyrite, and whole-rock geochemistry and Pb isotopes of the country rocks are used to study the source of fluids at Kuoerzhenkuola gold deposit. The ore-forming fluids are characterized by low–moderate temperatures and low salinities estimated from fluid inclusion microthermometry. Quadrupole mass spectrometry indicated a CO2-bearing fluid. Inductively coupled plasma–mass spectrometry of the fluid inclusions indicated high Cu (average 70 ppm) for the Au mineralization, whereas the host rocks have low Cu (average 33 ppm), indicating that Cu of the ore-forming fluids originated from magmatic fluid rather than the volcanic rocks. Pb isotopes of ores and host volcanic rocks indicate a similar, mixed source and some Pb could be sourced from the volcanism. This implied that magmatic fluids could play an important role in the Au mineralization process. These new geological findings and the fluids derived mainly from the magmatic fluids suggest that the ore-forming fluids originate at depth, and are transported and precipitated within the caldera fracture system. Thus, we proposed a conceptual target area at depth. A detailed Stratagem EH4 measurement was carried out to test the validity of the conceptual target. Stratagem EH4 soundings over six parallel traverses perpendicular to the mineralized trend showed that the caldera fracture system could extend for approximately 900 m in the dip direction at the center of the caldera, an indication of the presence of potential deep mineralization under the surveyed area. Detailed modeling of the Stratagem EH4 sounding images provided well-defined targets for test drilling. Subsequent test drilling on one of these targets, which extends down 850 m at an angle of 87°, returned encouraging results because four core-intercepts of gold ore bodies at down-hole depths of 40.5–42.0 m, 70.5–73.5 m, 357.0–358.5 m, and 384.5–385.5 m and a long interval gold mineralized body (0–720 m) were encountered. [ABSTRACT FROM AUTHOR]

Objective To analyze the trends of case detection and other indicators of leprosy in China during 1985-2002. Methods Data reported by each province were collected by China National Leprosy Database in Nanjing P.R.China. All data about registered cases were put into computer for analysis. Results From 1985 to 2002, a total of 49477 leprosy new cases had been detected. Among them, 69.5% were multi- bacillary cases and 25.4% had grade 2 disability. The child cases aged below 15 years accounted for 3.74% of total cases. Totally, 5824 cases and 303 cases relapsed after dapsone (DDS) mono-therapy and multidrug therapy (MI)T), respectively. Case detection showed a marked reduction from 0.47/100 000 in 1985 to 0.18/100 000 in 1993 although there were several spurts due to operational factors. From 1994, case detection showed no significant decline. The grade 2 disability among new patients decreased from 31.4% in 1985 to 23.4% in 2002. The child case detection rate among new cases fluctuated between 2.70%-3.56% from 1999 to 2002. The incidence of relapse declined after the introduction of DDS mono-therapy. However, it increased after the introduction of MDT. Conclusion China experiences in leprosy control show that it will take a long time with continuing present leprosy control activities to bring down the case detection and other indicators to a very low level even after reaching the elimination goal of leprosy. [ABSTRACT FROM AUTHOR]

Nasopharyngeal carcinoma (NPC) is characterized by a high prevalence in Southern China, especially among Cantonese individuals of the Guangdong Province. Epidemiological studies have suggested that frequent exposure to high levels of nitrosamine from preserved foods such as salted fish could be a risk factor for NPC. Cytochrome P450 encompasses a family of enzymes that metabolize carcinogens and CYP2A13, a member of this family, is expressed predominantly in the respiratory tract with the highest levels in the nasal mucosa. In an effort to test whether a correlation exists between CYP2A13 genetic polymorphism and the risk of developing NPC, we sequenced all nine exons and the exon-intron junctions of the CYP2A13 gene in 45 NPC patients. We identified a total of 21 single nucleotide polymorphism (SNPs), including 7 novel SNPs. The most frequent functional variant allele was 74A-1757G-3375T-7233G with a haplotype frequency of 7.8% in the 45 NPC cases. In addition, a stop codon mutation was detected in one case. We then selected the 3 most frequent SNPs and one stop codon mutation to expand our study to a casecontrol analysis within the Cantonese population. A novel haplotype consisting 8 SNPs in introns, and four additional novel SNPs were identified; but no correlation between CYP2A13 genetic polymorphism and individual susceptibility to NPC was observed. [ABSTRACT FROM AUTHOR]

Provides information on a study regarding biogenic gas and premature-low mature (PLM) associated gases in some medium and small-sized basins of Yanan Province in China. Sampling and analysis of gaseous samples; Discovery and theoretical study of PLM oil and the biothermocatalytic transitional zone gas; Conclusion.

The article discusses the first report of Klebsiella Pneumoniae Carbapenemase (KPC)-producing Pseudomonas aeruginosa in China in 2009. Three patients' faecal specimens out of 291 were found positive of the isolates in a surveillance study for assessing asymptomatic colonization with carbapenem-resistant organisms in the intensive care unit of the Zhejiang University College of Medicine. After these organisms were found in South America, the Caribbean islands and North America, the China report is said to indicate a potential worldwide spread.

Four isolates of Klebsiella pneumoniaeand one isolate of Enterobacter cloacaeexhibiting resistance to most β-lactam antibiotics, including oxyimino-cephalosporins and carbapenems, were obtained from different patients among four hospitals in China. Pulsed-field gel electrophoresis demonstrated that all the K. pneumoniaeisolates belonged to two clone patterns. Multilocus sequence typing showed that the four isolates of K. pneumoniaebelonged to two sequence types: ST 23 and ST 351. Conjugation studies with Escherichia coli(EC600) resulted in the transfer of reduced carbapenem susceptibility compared with that of the original isolates. Plasmid restriction analysis and hybridization experiment showed that the five isolates of Enterobacteriaceae carried a common 50 kb blaKPC-2-encoding plasmid. [ABSTRACT FROM AUTHOR]

Aim: To investigate fibroblast growth factor receptor 4 (FGFR4) protein expression in Chinese patients with resectable gastric cancer (GC) and the association with clinicopathological characteristics and survival., Methods: One hundred and seventy-five GC patients who underwent curative surgical procedures were enrolled in this study. The protein expression of FGFR4 in formalin-fixed, paraffin-embedded (FFPE) GC tissues was determined by immunohistochemical (IHC) analysis. Patient clinicopathological data and survival information were also collected and χ(2) statistical analysis was performed to analyze FGFR4 protein expression in the subgroups with differing clinicopathological characteristics including; gender, age, tumor location, differentiation, tumor-node-metastasis stage, macroscopic type, depth of invasion, lymph node metastases, distant metastasis, neural invasion and vascular invasion. Furthermore, some common molecular markers of GC in our cancer center, including p53, p27, topoisomerase IIα (Topo IIα) were also determined by IHC and their association with FGFR4 protein expression evaluated. The probability of survival for different subgroups with different clinicopathological characteristics was calculated using the Kaplan-Meier method and survival curves plotted using the log rank test., Results: Seventy seven cases (44%) were found to have high expression of FGFR4 protein. Significantly different FGFR4 expression was observed between gastric cancers with differing expression of Topo IIα (log rank χ(2) = 9.4760, P = 0.0236). No significant differences were observed between subgroups defined by any of the other clinicopathological characteristics. The median survival time of the FGFR4 high expression (77 cases) and low expression groups (98 cases) was 27 mo and 39 mo, respectively. The five-year survival rates and median survival times of gastric cancers with high FGFR4 expression were worse than those with low expression (30.8% vs 39.2%, 27 mo vs 39 mo), respectively, however, no significant difference was observed in survival time (log rank χ(2) = 1.0477, P = 0.3060). Survival analysis revealed that high expression of FGFR4 was a predictor of poor outcome in GC patients if the tumor was small (less than or equal to 3 cm in size) (log rank χ(2) = 5.5033, P = 0.0190), well differentiated (log rank χ(2) = 7.9757, P = 0.0047), and of T1 or T2 stage invasion depth (log rank χ(2) = 4.8827, P = 0.0271)., Conclusion: Our results suggest that high tumor expression of FGFR4 protein is not an independent risk factor for GC cancer initiation, but is a useful prognostic marker for GC patients when the tumor is relatively small, well differentiated, or in the early stages of invasion.