110 research outputs found

    Application of integrated formation evaluation and three-dimensional modeling in shale gas prospect identification

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    Identifying the shale gas prospect is crucial for gas extraction from suchreservoirs. Junggar Basin (in Northwest China) is widely considered tohave high potential as a shale gas resource, and the Jurassic, the mostsignificant gas source strata, is considered as prospective for shale gasexploration and development. This study evaluated the Lower JurassicBadaowan Formation shale gas potential combined with geochemical,geological, and well logging data, and built a three-dimensional (3D)model to exhibit favorable shale gas prospects. In addition, methane sorption capacity was tested for verifying the prospects. The Badaowan shalehad an average total organic carbon (TOC) content of 1.30 wt. % andvitrinite reflectance (Ro) ranging from 0.47% to 0.81% with dominatedtype III organic matter (OM). X-ray diffraction (XRD) analyses showedthat mineral composition of Badaowan shale was fairly homogeneous anddominated by clay and brittle minerals. 67 wells were used to identifyprospective shale intervals and to delineate the area of prospects. Consequently, three Badaowan shale gas prospects in the Junggar Basin wereidentified: the northwestern margin prospect, eastern Central Depressionprospect and Wulungu Depression prospect. The middle interval of thenorthwestern margin prospect was considered to be the most favorableexploration target benefitted by wide distribution and high lateral continuity. Generally, methane sorption capacity of the Badaowan shale wascomparable to that of the typical gas shales with similar TOC content,showing a feasible gas potential

    Copper Salt-Catalyzed Formation of a Novel Series of Triazole-Spirodienone Conjugates with Potent Anticancer Activity.

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    Copper salt-catalyzed oxidative amination resulted in the formation of a novel series of triazole-spirodienone conjugates, 4-triazolyl-1-oxa-4-azaspiro[4,5]deca-6,9-dien-3,8-diones and 4-triazolyl-1-oxa-4-azaspiro[4,5]deca-6,9-dien-8-ones. A single crystal of compound 1p among them was grown and analyzed by X-ray crystallography. These compounds were evaluated for their antiproliferative activities against MDA-MB-231, HeLa, A549 and MCF-7 cell lines. Most of them showed moderate to high anticancer potency in the four cancer cell lines. The discovery of the triazole-spirodienone conjugates as cytotoxic agents against cancer cells may open up a new field in which these novel small molecules could be further explored as promising anticancer agents

    Transcriptional activation of follistatin by Nrf2 protects pulmonary epithelial cells against silica nanoparticle-induced oxidative stress

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    Silica nanoparticles (SiO2 NPs) cause oxidative stress in respiratory system. Meanwhile, human cells launch adaptive responses to overcome SiO2 NP toxicity. However, besides a few examples, the regulation of SiO2 NP-responsive proteins and their functions in SiO2 NP response remain largely unknown. In this study, we demonstrated that SiO2 NP induced the expression of follistatin (FST), a stress responsive gene, in mouse lung tissue as well as in human lung epithelial cells (A549). The levels of Ac-H3(K9/18) and H3K4me2, two active gene markers, at FST promoter region were significantly increased during SiO2 NP treatment. The induction of FST transcription was mediated by the nuclear factor erythroid 2-related factor 2 (Nrf2), as evidenced by the decreased FST expression in Nrf2-deficient cells and the direct binding of Nrf2 to FST promoter region. Down-regulation of FST promoted SiO2 NP-induced apoptosis both in cultured cells and in mouse lung tissue. Furthermore, knockdown of FST increased while overexpression of FST decreased the expression level of NADPH oxidase 1 (NOX1) and NOX5 as well as the production of cellular reactive oxygen species (ROS). Taken together, these findings demonstrated a protective role of FST in SiO2 NP-induced oxidative stress and shed light on the interaction between SiO2 NPs and biological systems

    Pore structure characterization of Chang-7 tight sandstone using MICP combined with N2GA techniques and its geological control factors

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    Understanding the pore networks of unconventional tight reservoirs such as tight sandstones and shales is crucial for extracting oil/gas from such reservoirs. Mercury injection capillary pressure (MICP) and N(2) gas adsorption (N(2)GA) are performed to evaluate pore structure of Chang-7 tight sandstone. Thin section observation, scanning electron microscope, grain size analysis, mineral composition analysis, and porosity measurement are applied to investigate geological control factors of pore structure. Grain size is positively correlated with detrital mineral content and grain size standard deviation while negatively related to clay content. Detrital mineral content and grain size are positively correlated with porosity, pore throat radius and withdrawal efficiency and negatively related to capillary pressure and pore-to-throat size ratio; while interstitial material is negatively correlated with above mentioned factors. Well sorted sediments with high debris usually possess strong compaction resistance to preserve original pores. Although many inter-crystalline pores are produced in clay minerals, this type of pores is not the most important contributor to porosity. Besides this, pore shape determined by N(2)GA hysteresis loop is consistent with SEM observation on clay inter-crystalline pores while BJH pore volume is positively related with clay content, suggesting N(2)GA is suitable for describing clay inter-crystalline pores in tight sandstones

    Public awareness, emotional reactions and human mobility in response to the COVID-19 outbreak in China- A population-based ecological study

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    This work is supported by the West China Hospital COVID-19 Epidemic Science and Technology Project (No. HX-2019-nCoV-014 to Dr Song, No. HX-2019-nCoV-019 to Dr Zhang), Sichuan University Emergency Grant (No. 2020scunCoVyingji1002 to Dr Song, No. 2020scunCoVyingji1005 to Dr Zhang), and Emergency Grant form Science & Technology Department of Sichuan Providence (No. 2020YFS0007 to Dr Zhang). Publisher Copyright: © 2020 Cambridge University Press. All rights reserved.Background: The outbreak of COVID-19 generated severe emotional reactions, and restricted mobility was a crucial measure to reduce the spread of the virus. This study describes the changes in public emotional reactions and mobility patterns in the Chinese population during the COVID-19 outbreak. Methods: We collected data on public emotional reactions in response to the outbreak through Weibo, the Chinese Twitter, between January 1st and March 31st, 2020. Using anonymized location-tracking information, we analyzed the daily mobility patterns of approximately 90% of Sichuan residents. Results: There were three distinct phases of the emotional and behavioral reactions to the COVID-19 outbreak. The alarm phase (January 19th�26th) was a restriction-free period, characterized by few new daily cases, but enormous public negative emotions (the number of negative comments per Weibo post increased by 246.9 per day, 95%CI: 122.5�371.3), and a substantial increase in self-limiting mobility (from 45.6% to 54.5%, changing by 1.5% per day, 95%CI: 0.7%�2.3%). The epidemic phase (January 27th�February 15th) exhibited rapidly increasing numbers of new daily cases, decreasing expression of negative emotions (a decrease of 27.3 negative comments per post per day, 95%CI:-40.4�-14.2), and a stabilized level of self-limiting mobility. The relief phase (February 16th�March 31st) had a steady decline in new daily cases and decreasing levels of negative emotion and self-limiting mobility. Conclusions: During the COVID-19 outbreak in China, the public�s emotional reaction was strongest before the actual peak of the outbreak and declined thereafter. The change in human mobility patterns occurred before the implementation of restriction orders, suggesting a possible link between emotion and behavior.Peer reviewe

    Cytoplasmic Skp2 Expression Is Increased in Human Melanoma and Correlated with Patient Survival

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    BACKGROUND: S-phase kinase protein 2 (Skp2), an F-box protein, targets cell cycle regulators via ubiquitin-mediated degradation. Skp2 is frequently overexpressed in a variety of cancers and associated with patient survival. In melanoma, however, the prognostic significance of subcellular Skp2 expression remains controversial. METHODS: To investigate the role of Skp2 in melanoma development, we constructed tissue microarrays and examined Skp2 expression in melanocytic lesions at different stages, including 30 normal nevi, 61 dysplastic nevi, 290 primary melanomas and 146 metastatic melanomas. The TMA was assessed for cytoplasmic and nuclear Skp2 expression by immunohistochemistry. The Kaplan-Meier method was used to evaluate the patient survival. The univariate and multivariate Cox regression models were performed to estimate the hazard ratios (HR) at five-year follow-up. RESULTS: Cytoplasmic but not nuclear Skp2 expression was gradually increased from normal nevi, dysplastic nevi, primary melanomas to metastatic melanomas. Cytoplasmic Skp2 expression correlated with AJCC stages (I vs II-IV, P<0.001), tumor thickness (≤2.00 vs >2.00 mm, P<0.001) and ulceration (P = 0.005). Increased cytoplasmic Skp2 expression was associated with a poor five-year disease-specific survival of patients with primary melanoma (P = 0.018) but not metastatic melanoma (P>0.05). CONCLUSION: This study demonstrates that cytoplasmic Skp2 plays an important role in melanoma pathogenesis and its expression correlates with patient survival. Our data indicate that cytoplasmic Skp2 may serve as a potential biomarker for melanoma progression and a therapeutic target for this disease

    Soil, grain and water chemistry in relation to human selenium responsive diseases in Enshi District, China

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    Selenium deficiency (Keshan Disease) and toxicity diseases in humans occur within 20 km of each other in Enshi District in China and have been linked to environmental levels of Se. Low concentrations of Se are associated with Jurassic siltstones and sandstones, whereas high concentrations occur in areas underlain by Permian carbonaceous strata. Although these broad relationships between Se in the environment and the human population have been established previously, not all villages underlain by the carbonaceous strata suffer Se toxicity problems and the precise controls on Se distribution and availability have not been quantified. In the present study, soil, grain, drinking water and human hair samples are examined to determine the controls on Se availability in 3 Se environments in Enshi District. Five low-Se and Keshan Disease villages, 5 high-Se and no toxicity villages and 5 high-Se and toxicity villages were selected for the study. Results show that the majority of samples in the low-Se villages are deficient or marginal in Se, and that Se availability to plants is inhibited by adsorption onto organic matter and Fe oxyhydroxides in soil. Therefore, remediation strategies involving the application of Se fertiliser direct to the soil may not increase plant Se levels as expected. In the high-Se villages, localised lithological variations result in considerable ranges in Se concentrations in all sample types. Deficient and excessive levels of Se are recorded in samples from the same village. Selenium bioavailability in the high-Se toxicity villages is controlled by the total soil Se concentration and pH. A greater proportion of the Se is plant available in villages where the carbonaceous strata are interbedded with limestone. Villagers should be advised to avoid planting crops in these areas if possible
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