A small-scale silica gel column chromatography method for separating carbazole compounds from highly mature crude oil.

The concentration of carbazoles in highly mature crude oil is quite low, making it challenging to separate carbazole compounds for the gas chromatography-mass spectrometry (GC-MS) detection. This study presents a small-scale column chromatography method for separating carbazoles from highly mature crude oil using silica gel as a solid phase adsorbent and a Pasteur pipette as a separation device. The carbazole-rich crude oil from the Pearl River Mouth Basin was selected to explore the impact of reagent polarity and injection mode on the separation of carbazoles. The oil sample was eluted with solvents mixed with different volume proportions of n-hexane and dichloromethane and each eluted fraction was collected for GC-MS testing. The results indicated that increasing the reagent polarity caused the aromatic hydrocarbons and carbazole compounds in crude oil to be eluted sequentially. Most aromatic compounds in the crude oil could be selectively eluted using a reagent polarity ratio of 9:1 (Vn-hexane: Vdichloromethane), with no carbazole compounds. A significant amount of carbazole compounds were eluted in the polar segments of 8:2-6:4, with the eluted carbazoles concentration accounting for more than 98 % of the total concentration. Moreover, the concentration and recovery of carbazoles eluted by direct injection mode were about 10 % higher than those after adsorption by silica gel. The standard deviation of the parameter ratio for the separated carbazole compounds in the three groups of repeatable parallel experiments was less than 0.2 %. Our method is superior to traditional two-step method and C18 column method in separation efficiency and damage to human body. This method can be applied to both highly mature crude oil and other kinds of oils including biodegradable oil. It could be a versatile method for the carbazoles separation and provide technical support in unveiling the geochemical implications of these compounds in complex areas.

APPL1 Is a Prognostic Biomarker and Correlated with Treg Cell Infiltration via Oxygen-Consuming Metabolism in Renal Clear Cell Carcinoma.

Kidney renal clear cell carcinoma (KIRC) is one of the most hazardous tumors in the urinary system. The regulation of oxygen consumption in renal clear cell carcinoma is a consequence of adaptive reprogramming of oxidative metabolism in tumor cells. APPL1 is a signaling adaptor involved in cell survival, oxidative stress, inflammation, and energy metabolism. However, the correlation of APPL1 with regulatory T cell (Treg) infiltration and prognostic value in KIRC remain unclear. In this study, we comprehensively predicted the potential function and prognostic value of APPL1 in KIRC. For KIRC patients, relatively low expression of APPL1 was associated with high degree of metastasis, pathological stage, and shorter overall time or poor prognosis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses suggested that low expression of APPL1 may be adapted to the malignant progression of tumors via affecting oxygen-consuming metabolism. In addition, the expression level of APPL1 was negatively correlated with Treg cell infiltration and chemotherapy sensitivity, which indicated that APPL1 may regulate the tumor immune infiltration and chemotherapy resistance by decrease oxygen-consuming metabolic process in KIRC. Therefore, APPL1 may become one of the important prognostic factors, and it may serve as a candidate prognostic biomarker in KIRC.

Novel efficient capture of Cr(VI) from soil driven by capillarity and evaporation coupling.

Soil contaminated by hexavalent chromium (Cr(VI)) poses a severe environmental threat owing to the carcinogenic and genotoxic characteristics of Cr(VI). Currently, field application of remediation technologies for Cr(VI) removal or detoxification fails to achieve optimum results owing to various limitations, such as high energy consumption, high chemical cost, secondary pollution, and long treatment duration. Herein, a novel strategy, namely, the capillary-evaporation membrane (CEM) method, which is based on the ubiquitous phenomena of capillarity and evaporation in natural soil environment without external forces, was applied to remove Cr(VI) from contaminated soil. The CEM method enables Cr(VI) dissolved in the soil solution to move upwards through soil pores and inter-particle spaces and get attached to the surface of adsorption membrane under the coupling action of capillarity and evaporation to achieve Cr(VI) removal. The CEM method showed high Cr(VI) removal capacity during 22 days of treatment of bulk soil (47.26%), sandy fraction (34.60%), and silt-clay fraction (52.50%), respectively. Further research on optimization of the CEM process conditions could remarkably improve Cr(VI) remediation performance. For example, the Cr(VI) removal rate increased to 89.04% in bulk soil through prolongation of the remediation period to 61 days. This study demonstrated a new environment-friendly remediation method driven by natural phenomena for Cr(VI)-contaminated soils.

Nrf2-SHP Cascade-Mediated STAT3 Inactivation Contributes to AMPK-Driven Protection Against Endotoxic Inflammation.

Signal transducer and activator of transcription 3 (STAT3) is implicated in inflammation processing, but the mechanism of its regulation mostly remains limited to Janus kinase (JAK)-mediated phosphorylation. Although AMP-activated protein kinase (AMPK)-mediated STAT3 inactivation has got documented, the molecular signaling cascade connecting STAT3 inactivation and the anti-inflammatory role of AMPK is far from established. In the present study, we addressed the interplay between AMPK and STAT3, and revealed the important role of STAT3 inactivation in the anti-inflammatory function of AMPK in lipopolysaccharide-stressed macrophages and mice. Firstly, we found that pharmacological inhibition of STAT3 can improve the anti-inflammatory effect of AMPK in wild-type mice, and the expression of STAT3 in macrophage of mice is a prerequisite for the anti-inflammatory effect of AMPK. As to the molecular signaling cascade linking AMPK to STAT3, we disclosed that AMPK suppressed STAT3 not only by attenuating JAK signaling but also by activating nuclear factor erythroid-2-related factor-2 (Nrf2), a redox-regulating transcription factor, which consequently increased the expression of small heterodimer protein (SHP), thus repressing the transcriptional activity of STAT3. In summary, this study provided a unique set of evidence showing the relationship between AMPK and STAT3 signaling and explored a new mechanism of AMPK-driven STAT3 inactivation that involves Nrf2-SHP signaling cascade. These findings expand our understanding of the interplay between pro- and anti-inflammatory signaling pathways and are beneficial for the therapeutic development of sepsis treatments.

Autolysosomal degradation of cytosolic chromatin fragments antagonizes oxidative stress-induced senescence.

Oxidative stress-induced DNA damage, the senescence-associated secretory phenotype (SASP), and impaired autophagy all are general features of senescent cells. However, the cross-talk among these events and processes is not fully understood. Here, using NIH3T3 cells exposed to hydrogen peroxide stress, we show that stress-induced DNA damage provokes the SASP largely via cytosolic chromatin fragment (CCF) formation, which activates a cascade comprising cGMP-AMP synthase (cGAS), stimulator of interferon genes protein (STING), NF-κB, and SASP, and that autolysosomal function inhibits this cascade. We found that CCFs accumulate in senescent cells with activated cGAS-STING-NF-κB signaling, promoting SASP and cellular senescence. We also present evidence that the persistent accumulation of CCFs in prematurely senescent cells is partially associated with a defect in DNA-degrading activity in autolysosomes and reduced abundance of activated DNase 2α. Intriguingly, we found that metformin- or rapamycin-induced activation of autophagy significantly lessened the size and levels of CCFs and repressed the activation of the cGAS-STING-NF-κB-SASP cascade and cellular senescence. These effects of autophagy activators indicated that autolysosomal function contributes to CCF clearance and SASP suppression, further supported by the fact that the lysosome inhibitor bafilomycin A1 blocked the role of autophagy-mediated CCF clearance and senescence repression.

Sulfur Transfer Versus Phenyl Ring Transfer in the Gas Phase: Sequential Loss of CH3OH and CH3O-P=O from Protonated Phosphorothioates.

Collisional activation fragmentation of protonated phosphorothioates leads to skeletal rearrangement and formation of aryl sulfenylium cation (R-PhS+) via successive eliminations of CH3OH and CH3O-P=O. To better understand this unusual fragmentation reaction, isotope-labeling experiments and density functional theory (DFT) calculations were carried out to investigate two mechanistic pathways. In route 1, a direct intramolecular transfer of the R-phenyl group occurs from the oxygen atom to the sulfur atom on thiophosphoryl to form methoxyl S-(3-methyl-4-methylsulfanyl-phenyl) phosphonium thiolate (a4), which subsequently dissociates to form the m/z 169 cation. In route 2, the sulfur atom of the thiophosphoryl group undergoes two stepwise transfer (1,4-migration to the ortho-carbon atom of the phenyl ring followed by 1,2-migration to the ipso-carbon atom) to form an intermediate isomer, which undergoes the subsequent dissociation to form the m/z 169 cation. DFT calculations suggested that route 2 was more favorable than route 1 from the point view of kinetics. Graphical Abstract.

Highly efficient treatment of real benzene dye intermediate wastewater by simple limestone and lime neutralization-coagulation with improved Fenton oxidation.

Multistage Fenton oxidation is a favored method for the treatment of benzene dye intermediate (BDI) wastewater, but the pH adjustments required after each stage of the Fenton process with a simple way is still a challenge. Limestone pretreatment and lime neutralization-coagulation were used to solve the problem in multistage Fenton process. First, we determined the optimal conditions of Fenton oxidation using the Box-Behnken response surface method. Limestone pretreatment before the multistage Fenton process allowed for simultaneous pH adjustment and 14.15% COD removal. Most notably, the lime cream neutralization-coagulation process effectively adjusted the pH after each stage of the Fenton process. The optimum CaO particle size, lime mass fraction, mixing time, and stirring speed were determined by orthogonal tests. COD removal (89.23%) was obtained when lime cream neutralization-coagulation was applied to the three-staged Fenton process, while only 58.57% COD removal was obtained by the unadjusted single-staged Fenton process. The COD and wastewater color were reduced from 10,600 mg/L and 12,200 multiples to 495 mg/L and 20 multiples, respectively, using the adjusted process. This improved method provides a promising cost-effective way to efficiently treat real BDI wastewater.

Phylogeny and polymorphism in the long control regions E6, E7, and L1 of HPV Type 56 in women from southwest China.

Globally, human papillomavirus (HPV)­56 accounts for a small proportion of all high­risk HPV types; however, HPV­56 is detected at a higher rate in Asia, particularly in southwest China. The present study analyzed polymorphisms, intratypic variants, and genetic variability in the long control regions (LCR), E6, E7, and L1 of HPV­56 (n=75). The LCRs, E6, E7 and L1 were sequenced using a polymerase chain reaction and the sequences were submitted to GenBank. Maximum­likelihood trees were constructed using Kimura's two­parameter model, followed by secondary structure analysis and protein damaging prediction. Additionally, in order to assess the effect of variations in the LCR on putative binding sites for cellular proteins, MATCH server was used. Finally, the selection pressures of the E6­E7 and L1 genes were estimated. A total of 18 point substitutions, a 42­bp deletion and a 19­bp deletion of LCR were identified. Some of those mutations are embedded in the putative binding sites for transcription factors. 18 single nucleotide changes occurred in the E6­E7 sequence, 11/18 were non­synonymous substitutions and 7/18 were synonymous mutations. A total 24 single nucleotide changes were identified in the L1 sequence, 6/24 being non­synonymous mutations and 18/24 synonymous mutations. Selective pressure analysis predicted that the majority of mutations of HPV­56 E6, E7 and L1 were of positive selection. The phylogenetic tree demonstrated that the isolates distributed in two lineages. Data on the prevalence and genetic variation of HPV­56 types in southwest China may aid future studies on viral molecular mechanisms and contribute to future investigations of diagnostic probes and therapeutic vaccines.

The inhibitory effect in Fraxinellone on oxidative stress-induced senescence correlates with AMP-activated protein kinase-dependent autophagy restoration.

As a natural metabolite of limonoids from Dictamnus dasycarpus, fraxinellone has been reported to be neuroprotective and anti-inflammatory. However, its influence on cellular metabolism remains largely unknown. In the present study, we investigated the effect of fraxinellone on cellular senescence-induced by oxidative stress and the potential mechanism. We found that fraxinellone administration caused growth arrest and certainly repressed the activity of senescence associated ß-galactosidase as well as the expression of senescence-associated-genes. Interestingly, this effect of fraxinellone is closely correlated with the restoration of impaired autophagy and the activation of AMPK. Notably, fraxinellone reacts in an AMPK-dependent but mTORC1-independent manner. Together, our study demonstrates for the first time that fraxinellone has the effect on senescence inhibition and AMPK activation, and supports the notion that autophagic mechanism is important for aging prevention. These findings expanded the list of natural compounds and will be potentially utilized for aging decay and/or AMPK activation.

Study on the degradation mechanism and pathway of benzene dye intermediate 4-methoxy-2-nitroaniline via multiple methods in Fenton oxidation process.

Benzene dye intermediate (BDI) 4-methoxy-2-nitroaniline (4M2NA) wastewater has caused significant environmental concern due to its strong toxicity and potential carcinogenic effects. Reports concerning the degradation of 4M2NA by advanced oxidation process are limited. In this study, 4M2NA degradation by Fenton oxidation has been studied to obtain more insights into the reaction mechanism involved in the oxidation of 4M2NA. Results showed that when the 4M2NA (100 mg L-1) was completely decomposed, the TOC removal efficiency was only 30.70-31.54%, suggesting that some by-products highly recalcitrant to the Fenton oxidation were produced. UV-Vis spectra analysis based on Gauss peak fitting, HPLC analysis combined with two-dimensional correlation spectroscopy and GC-MS detection were carried out to clarify the degradation mechanism and pathway of 4M2NA. A total of nineteen reaction intermediates were identified and two possible degradation pathways were illustrated. Theoretical TOC calculated based on the concentration of oxalic acid, acetic acid, formic acid, and 4M2NA in the degradation process was nearly 94.41-97.11% of the measured TOC, indicating that the oxalic acid, acetic acid and formic acid were the main products. Finally, the predominant degradation pathway was proposed. These results could provide significant information to better understand the degradation mechanism of 4M2NA.

FTO is required for myogenesis by positively regulating mTOR-PGC-1α pathway-mediated mitochondria biogenesis.

Global germ line loss of fat mass- and obesity-associated (FTO) gene results in both the reduction of fat mass and lean mass in mice. The role of FTO in adipogenesis has been proposed, however, that in myogenesis has not. Skeletal muscle is the main component of body lean mass, so its connection with FTO physiologic significance need to be clarified. Here, we assessed the impact of FTO on murine skeletal muscle differentiation by in vitro and in vivo experiments. We found that FTO expression increased during myoblasts differentiation, while the silence of FTO inhibited the differentiation; in addition, skeletal muscle development was impaired in skeletal muscle FTO-deficient mice. Significantly, FTO-promoted myogenic differentiation was dependent on its m6A demethylase activity. Mechanically, we found that FTO downregulation suppressed mitochondria biogenesis and energy production, showing as the decreased mitochondria mass and mitochondrial DNA (mtDNA) content, the downregulated expression of mtDNA-encoding genes and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) gene, together with declined ATP level. Moreover, the involvement of mTOR-PGC-1α pathway in the connection between FTO and muscle differentiation is displayed, since the expression of FTO affected the activity of mTOR and rapamycin blocked FTO-induced PGC-1α transcription, along with the parallel alteration pattern of FTO expression and mTOR phosphorylation during myoblasts differentiation. Summarily, our findings provide the first evidence for the contribution of FTO for skeletal muscle differentiation and a new insight to study the physiologic significance of RNA methylation.

Genetic variability in E6, E7, and L1 genes of human papillomavirus genotype 52 from Southwest China.

Human papillomavirus (HPV) is the major causative agent of cervical cancer, which accounts for the second highest cancer burden in women worldwide. HPV-52, the prevalent subtype in Asia, especially in southwest China, was analyzed in this study. To analyze polymorphisms, intratypic variants, and genetic variability in the E6-E7 (n=26) and L1 (n=53) genes of HPV-52, these genes were sequenced and the sequences were submitted to GenBank. Phylogenetic trees were constructed using the neighbor-joining and Kimura 2-parameters methods, followed by analysis of the diversity of secondary structure. Finally, we estimated the selection pressures acting on the E6-E7 and L1 genes. Fifty-one novel variants of HPV-52 L1, and two novel variants of HPV-52 E6-E7 were identified in this study. Thirty single nucleotide changes were observed in HPV-52 E6-E7 sequences with 19/30 non-synonymous mutations and 11/30 synonymous mutations (five in the alpha helix and five in the beta sheet). Fifty-five single nucleotide changes were observed in HPV-52 L1 sequences with 17/55 non-synonymous mutations (seven in the alpha helix and fourteen in the beta sheet) and 38/55 synonymous mutations. Selective pressure analysis predicted that most of these mutations reflect positive selection. Identifying new variants in HPV-52 may inform the rational design of new vaccines specifically for women in southwest China. Knowledge of genetic variation in HPV may be useful as an epidemiologic correlate of cervical cancer risk, or may even provide critical information for developing diagnostic probes.

Association of polymorphisms in tektin-t gene with idiopathic asthenozoospermia in Sichuan, China.

PURPOSE: The purpose of this research was to study the association between the single nucleotide polymorphisms (SNPs) of the tektin-t gene and idiopathic asthenozoospermia. METHODS: We conducted sequence analyses of the tektin-t gene in 104 idiopathic asthenozoospermia and 102 fertile men with normospermic parameters in Sichuan, China. RESULTS: In this study, we found that allele 136 T (odds ratio [OR] 1.745, 95 % confidence interval [CI] 1.146-2.655, P = 0.009) was significantly increased in idiopathic asthenozoospermic patients compared with fertile men. This mutation substitutes a highly conserved arginine at position 46 to cysteine. Moreover, PolyPhen-2 analysis predicted that this variant was "probably damaging". In addition, a novel heterozygous mutation, R207H (c.620G >A), was detected in five asthenozoospermic patients, while there was no detection of this genotype among the fertile candidates, indicating that the mutation was located within a conserved domain predicted by PolyPhen-2 analysis as "probably damaging" to the protein. CONCLUSIONS: These results suggested that tektin-t variants (Arg/Cys + Cys/Cys) were probably one of the high risk genetic factors for idiopathic asthenozoospermia among males in Sichuan, China, while the R207H polymorphism may be associated with idiopathic asthenozoospermia risk.

Microscopic Fluorescence Spectral Characteristics of Mixing Ratio of Crude Oil Experiment.

The microscopic fluorescence spectroscopy has become a mature technology of fluid inclusions test and analysis system, which is used to distinguish different types of crude oil and oil inclusions. These would be the important basis to study the history of hydrocarbon accumulation of petroleum basins. The mixture of crude oil from different sources could occur in migration and accumulation process. In order to effectively identify the type of geological process, mixing ratio of crude oil experiment has been carried out. This study result shows that mixing of crude oil make fluorescence color and spectral parameters(λmax, QF535 and CIE-XY) change nonlinearly. Fluorescence spectral parameters of mixed oil is between end member oil A and B. The greater A or B ratio of mixed oil, the closer to A or B. Fluorescence color of mixed oil show nonlinear and gradual change in CIE-XY chromaticity diagram. Variation of spectral spectrum shape show that single peak is changed into double and three peaks. The relationship between QF535 and degree of mixing could calculate quantitatively relative contribution. Mixing different types of crude oil make spectral spectrum shape changes, which present characteristics of two peaks and three peaks but not unimodal peak. The main and subsidiary wavelength reserve wavelength information of end member oils. Based on variation characteristics of fluorescence spectrum, there are three different types of oil including blue, blue-green and yellow fluorescing oil filling in the bottom member of Pinghu formation in A gas field. At the same time, there also was a mixing process of blue-green fluorescing oil and yellow fluorescing oil. The degree of mixing is 47%~55%.

[Secondary Alterations Influence on Fluorescence Color and Spectral Parameters of Crude Oil and Oil Inclusion].

Based on oil samples and rock samples in several petroliferous basins, this paper studied that secondary alterations influence on fluorescence color and spectral parameters of crude oil and oil inclusions by using microscopic fluorescent spectral and geochemical parameters. The results demonstrated that secondary alterations influence on spectral parameters by changing the ratio of saturated hydrocarbon and aromatic hydrocarbon (saturation/aromatics). Biodegradation and water washing lead to redshift of fluorescence parameters while evaporative fractionation and oil cracking lead to blueshift. Beside, mixed oil lead to redshift and blueshift. The secondary alterations and main period of accumulation in research area were recognized by frequency histogram of crude oil and oil inclusion. The relationship between QF-535 and the parameters measuring the secondary alterations could the extent of secondary alterations from which crude oil suffered. In the microscopic fluorescence test, oil inclusions suffered from stretch or leakage, thermal cracking and photooxidation should be rejected.

Six polymorphisms in genes involved in DNA double-strand break repair and chromosome synapsis: association with male infertility.

Four genes involved in DNA double-strand break repair and chromosome synapsis, i.e., testis expressed gene 11 (TEX11), testis expressed gene 15 (TEX15), mutL homolog 1 (MLH1), and homolog 3 (MLH3), play critical roles in genome integrity, meiotic recombination, and gametogenesis. We explored the possible association between single nucleotide polymorphisms (SNPs) in these genes and idiopathic male infertility involving azoospermia or oligozoospermia. A total of 614 fertile control and infertile men were recruited to this study in Sichuan, China. The latter group included 244 men with azoospermia and 72 men with oligozoospermia. Six SNPs in the TEX11, TEX15, MLH1, and MLH3 genes were investigated in both patients and controls by sequencing. The frequency distributions of SNPs rs6525433, rs175080, rs6525433-rs4844247, and rs1800734-rs175080 were found to be significantly different between patients and control groups (p < 0.05), while rs4844247, rs323344, rs323346, and rs1800734 showed no significant difference between the two cohorts. Thus, the SNPs TEX11 rs6525433, MLH3 rs175080, rs6525433-rs4844247, and rs1800734-rs175080 might be associated with male infertility.

Profile of organochlorine pesticides in soil cores from some hotspot areas of Beijing, China.

For the valid use of urban land and the safety of public health, an extensive contamination survey of organochlorine pesticides from five soil cores was conducted in the highly urbanized areas of Beijing in China. For topsoils in five soil cores, level of ∑HCHs and ∑DDTs varied from 0.174 to 4,783 ng g(-1) and 0.62 to 57,849 ng g(-1), respectively. The profile in topsoil of cores displayed that levels of pollutants in four soil cores from the urban areas with dense population are higher than that from outskirts. The depth characteristics of pollutants indicated that the level of ∑HCHs and ∑DDTs in BY and WU was close to/below the background value of soil in China (50 ng g(-1)), but those in some soil samples from A, B and ZX core, especially A and B, was above the threshold value for the soil safety (1,000 ng g(-1)). In views of the usage history of the land and profiles of contaminants, the source in A and B probably came from the dumped waste chemical materials in the old chemical factories. The study of soil cores sampled revealed the existence of chemical "time bomb" in urban regions of Beijing. Also, the finding indicated the absolute necessity of assessing the soil quality with the unprecedented land use changes in the big city community.

[Effects of benzene, toluene on reductive dechlorination of trichloroethylene and its daughter product cis-1,2-dichloroethylene by granular iron].

Mixed plumes contained chlorinated solvents and petroleum hydrocarbons which mainly refers to BTEX (benzene, toluene, ethylbenzene and xylenes) in groundwater can be remediated by sequential units combined an iron permeable reactive barrier (Fe0-PRB) with an anoxic wall. In design of the Fe0-PRB it should be taken into account the necessity of altering the width of the iron cell in the presence of BTEX. Three column experiments were conducted to evaluate the effects of benzene, toluene on the long-term performance of reductive dechlorination of trichloroethylene (TCE) by granular iron. The results showed that the kinetics of TCE (at the initial concentration of 2 mg x L(-1) more or less) reduction was accorded with pseudo first-order even in the presence of benzene or toluene (at about 1-2 mg x L(-1), respectively). The existence of benzene and toluene inhibited the removal of TCE by 15.1% and 18. 5% , respectively; however, the presence of benzene slightly increased cis-1,2-DCE reduction rate by 4.5%, and the presence of toluene increased cis-1,2-DCE reduction rate by 42.8%. The inhibition of benzene and toluene other than mineral precipitates was not one of the decisive factors in the long-term performance of an Feo-PRB; in addition, the kinds of chlorinated daughter products of TCE in the presence/absence of benzene or toluene were identical and cis-1,2-dichloroethylene (cis-1,2-DCE), the major intermediate, firstly broke through from all the 3 columns at concentrations about 2-75 microg x L(-1), indicating that designing the width of an Fe0-PRB should be based on the hydraulic residence time of cis-1,2-DCE. In conclusion, if only considering the TCE remedial goals and disregarding the effects of cis-1,2-DCE on BTEX biodegradation downgradient the Fe0-PRB, the results suggested that it should be not necessary to increase the width of the iron cell for constructing sequential permeable reactive barriers (SPRBs) to rescue TCE- and BTEX-contaminated aquifers.

Hydrocarbon charging histories of the Ordovician reservoir in the Tahe oil field, Tarim Basin, China.

The Ordovician reservoir of the Tahe oil field went through many tectonic reconstructions, and was characterized by multiple hydrocarbon chargings. The aim of this study was to unravel the complex charging histories. Systematic analysis of fluid inclusions was employed to complete the investigation. Fluorescence observation of oil inclusions under UV light, and microthermometry of both oil and aqueous inclusions in 105 core samples taken from the Ordovician reservoir indicated that the Ordovician reservoir underwent four oil chargings and a gas charging. The hydrocarbon chargings occurred at the late Hercynian, the Indo-Sinian and Yanshan, the early Himalaya, the middle Himalaya, and the late Himalaya, respectively. The critical hydrocarbon charging time was at the late Hercynian.