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Now showing items 65 - 80 of 136

  • Numerical Analysis of Vibration Responses in High-Speed Railways considering Mud Pumping Defect

    Li, Ting   Su, Qian   Shao, Kang   Liu, Jie  

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  • PTEN regulates RPA1 and protects DNA replication forks

    Wang, Guangxi   Li, Yang   Wang, Pan   Liang, Hui   Cui, Ming   Zhu, Minglu   Guo, Limei   Su, Qian   Sun, Yujie   McNutt, Michael A.  

    Tumor suppressor PTEN regulates cellular activities and controls genome stability through multiple mechanisms. In this study, we report that PTEN is necessary for the protection of DNA replication forks against replication stress. We show that deletion of PTEN leads to replication fork collapse and chromosomal instability upon fork stalling following nucleotide depletion induced by hydroxyurea. PTEN is physically associated with replication protein A 1 (RPA1) via the RPA1 C-terminal domain. STORM and iPOND reveal that PTEN is localized at replication sites and promotes RPA1 accumulation on replication forks. PTEN recruits the deubiquitinase OTUB1 to mediate RPA1 deubiquitination. RPA1 deletion confers a phenotype like that observed in PTEN knockout cells with stalling of replication forks. Expression of PTEN and RPA1 shows strong correlation in colorectal cancer. Heterozygous disruption of RPA1 promotes tumorigenesis in mice. These results demonstrate that PTEN is essential for DNA replication fork protection. We propose that RPA1 is a target of PTEN function in fork protection and that PTEN maintains genome stability through regulation of DNA replication.
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  • Sex-Specific Associations Between Complement Component 3 and Component 4 Levels and Metabolic Syndrome in an Adult Population

    Meng, Ge   Li, Huihui   Li, Yajun   Zhang, Qing   Liu, Li   Wu, Hongmei   Xia, Yang   Bao, Xue   Gu, Yeqing   Su, Qian   Fang, Liyun   Yang, Huijun   Yu, Fei   Shi, Hongbin   Sun, Shaomei   Wang, Xing   Zhou, Ming   Jia, Qiyu   Song, Kun   Chang, Hong   Wu, Yuntang   Niu, Kaijun  

    Background: Metabolic syndrome (MetS) is a cluster of cardiovascular and metabolic risk factors in the same individual. Inflammation has been reported to be directly involved in the development of metabolic disease. Complement component 3 (C3) and complement component 4 (C4) have been identified as important inflammatory markers relevant to metabolic disease. However, few studies have analyzed the association between C3 and/or C4 and MetS. In this study, our aim is to evaluate sex-specific association between C3 and C4 levels and risk of MetS in an adult population. Methods: A cohort of 4635 adults was followed from 2010 to 2016. Serum C3 and C4 levels were measured using an immunonephelometric technique. MetS was defined by the American Heart Association scientific statements of 2009. Cox proportional hazard regression models were used to assess sex-specific association between C3 and C4 levels and the incidence of MetS. Results: During the approximate to 6 years of follow-up, 1445 new cases of MetS were identified. After being adjusted to confounding factors, the hazard ratios (95% confidence interval) of MetS for gradually increasing quintiles of C3 were 1.00, 1.23 (0.98-1.54), 1.50 (1.21-1.87), 1.64 (1.32-2.04), and 1.75 (1.41-2.18) (P for trend <0.0001) in men and 1.00, 0.96 (0.60-1.53), 1.61 (1.06-2.44), 2.01 (1.34-3.03), and 2.43 (1.63-3.63) (P for trend <0.0001) in women, respectively. Similar results were also obtained for gradually increasing quintiles of C4 in women, but not in men. Conclusions: The levels of C3 were significantly associated with the incidence of MetS in both men and women. The levels of C4 contributed to risk of MetS only in women.
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  • Assessment of the use of fiberglass-reinforced foam concrete in high-speed railway bridge approach involving foundation cost comparison

    Liu, Kai-Wen   Yue, Fei   Su, Qian   Zhou, Chuanbin   Xiong, Zhipeng   He, Yi  

    In view of the limited use of foam concrete for backfilling high-speed railway bridge approach and no publication considering the associated foundation treatment cost, this article presents a series of laboratory tests to study the mechanical properties of fiberglass-reinforced foam concrete with different contents of fiberglass, whereby the optimal values of target density and fiberglass content for fiberglass-reinforced foam concrete are obtained. A numerical model is developed to investigate the performance of bridge approach filled with fiberglass-reinforced foam concrete under different levels of foundation treatment in comparison with the control group with traditional backfills (combination of graded crushed stone and cement). Results indicate that the application of fiberglass-reinforced foam concrete to fill high-speed railway bridge approach can significantly improve the bridge approach performance (decreasing the horizontal displacement and ground surface settlement, respectively, by 58% and 21% than the control group) and cut down the foundation treatment cost by 19% concurrently.
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  • Cascade Claisen and Meinwald Rearrangement for One-Pot Divergent Synthesis of Benzofurans and 2 H -Chromenes

    Song, Liyan   Su, Qian   Lin, Xi   Du, Zhihui   Xu, Huiyou   Ouyang, Ming-An   Yao, Hongliang   Tong, Rongbiao  

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  • Ionic liquids with multiple active sites supported by SBA-15 for catalyzing conversion of CO2 into cyclic carbonates

    Shi, Zijie   Su, Qian   Ying, Ting   Tan, Xin   Deng, Lili   Dong, Li   Cheng, Weiguo  

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  • Transcriptomic analysis reveals key early events of narciclasine signaling in Arabidopsis root apex

    Cao, Xiaoning   Ma, Fei   Xu, Tingting   Wang, Junjie   Liu, Sichen   Li, Gaihong   Su, Qian  

    Histochemical staining and RNA-seq data demonstrated that the ROS- and plant hormone-regulated stress responses are the key early events of narciclasine signaling in Arabidopsis root cells.Narciclasine, an amaryllidaceae alkaloid isolated from Narcissus tazetta bulbs, employs a broad range of functions on plant development and growth. However, its molecular interactions that modulate these roles in plants are not fully understood. To elucidate the global responses of Arabidopsis roots to short-term narciclasine exposure, we first measured the accumulation of H2O2 and O-2 (-) with histochemical staining, and then profiled the gene expression pattern in Arabidopsis root tips treated with 0.5 A mu M narciclasine across different exposure times by RNA-seq. Physiological measurements showed a significant increase in H2O2 began at 30-60 min of narciclasine treatment and O-2 (-) accumulated by 120 min. Compared with controls, 236 genes were upregulated and 54 genes were downregulated with 2 h of narciclasine treatment, while 968 genes were upregulated and 835 genes were downregulated with 12 h of treatment. The Gene Ontology analysis revealed that the differentially expressed genes were highly enriched during oxidative stress, including those involved in the "regulation of transcription", "response to oxidative stress", "plant-pathogen interaction", "ribonucleotide binding", "plant cell wall organization", and "ribosome biogenesis". Moreover, Kyoto Encyclopedia of Genes and Genomes pathway enrichment statistics suggested that carbohydrate metabolism, amino acid metabolism, amino sugar and nucleotide sugar metabolism, and biosynthesis of phenylpropanoid and secondary metabolites were significantly inhibited by 12 h of narciclasine exposure. Hence, our results demonstrate that hormones and H2O2 are important regulators of narciclasine signaling and help to uncover the factors involved in the molecular interplay between narciclasine and phytohormones in Arabidopsis root cells.
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  • Blood Neutrophil to Lymphocyte Ratio as a Predictor of Hypertension.

    Liu, Xing   Zhang, Qing   Wu, Hongmei   Du, Huanmin   Liu, Li   Shi, Hongbin   Wang, Chongjin   Xia, Yang   Guo, Xiaoyan   Li, Chunlei   Bao, Xue   Su, Qian   Sun, Shaomei   Wang, Xing   Zhou, Ming   Jia, Qiyu   Zhao, Honglin   Song, Kun   Niu, Kaijun  

    BACKGROUND: Hypertension is a significant global public health challenge. Low-grade inflammation is known to facilitate the development of essential hypertension and target-organ hypertensive damage. Neutrophil to lymphocyte ratio (NLR) is a simple and reliable indicator of inflammation that may also be useful in the prediction of hypertension.; METHODS: Participants were recruited from Tianjin Medical University's General Hospital-Health Management Centre. A total of 28,850 initially hypertension-free subjects were followed from 2007 to 2013. Adjusted Cox proportional hazards regression models were used to assess relationships between NLR categories and incidence of hypertension.; RESULTS: During the ~6-year follow-up period (median duration of follow-up (interquartile range): 2.63 (2.58-2.68)), 1,824 subjects developed hypertension. The hazard ratios of hypertension incidence were evaluated in increasing NLR quintiles. Compared with participants with the lowest NLR levels, the multivariable-adjusted hazard ratios (95% confidence interval) of hypertension were related to increasing NLR quintiles and were as follows: 1.08 (0.92, 1.26), 0.97 (0.83, 1.14), 1.10 (0.94, 1.28), and 1.23 (1.06, 1.43), respectively (P for trend < 0.01). Similar results also were observed in the white blood cell and neutrophil counts, but not lymphocyte counts.; CONCLUSIONS: The study is the first to show the elevated NLR levels significantly correlate with an increased risk of developing hypertension. This result may be useful in elucidating the mechanism underlying the development of hypertension. New therapeutic approaches aimed at inflammation might be proposed to control hypertension and hypertensive damage. =C2=A9 American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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  • Synthesis of Cyclic Carbonate Catalyzed by DBU Derived Basic Ionic Liquids

    Li, Wei   Cheng, Weiguo   Yang, Xia   Su, Qian   Dong, Lihui   Zhang, Pan   Yi, Yunan   Li, Bin   Zhang, Suojiang  

    In this work, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]-5-nonene (DBN), and imidazole (MIM)-derived bromide ionic liquids (ILs) were synthesized and used to catalyze the cycloaddition reactions of carbon dioxide (CO2) with several kinds of epoxides to form cyclic carbonates. The DBU derived bromide ionic liquid system was found to have the best catalytic activity among all the tested ILs. The influences of reaction conditions (including temperature, pressure and reaction time) on the reaction of CO2 to propylene oxide (PO) were studied to show the best conditions of 120 degrees C, 1 MPa, 2.5 h catalyzed by 2 mol% DBU-derived bromide ionic liquid, with the conversion of PO and the selectivity of propylene carbonate (PC) reaching 99% and 99%, respectively. Under the optimum reaction conditions, the ionic liquid system could be reused at least five times without decrease in selectivity and conversion. NMR spectroscopy and DFT calculations were used to reveal the hydrogen-bond interaction between ionic liquids and reagent, based on which the reaction mechanism was proposed.
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  • Increased serum ferritin levels are independently associated with carotid atherosclerosis in women

    Xu, Haiyan   Song, Yanqi   Xu, Jing   Gu, Yeqing   Zhang, Qing   Liu, Li   Meng, Ge   Wu, Hongmei   Xia, Yang   Bao, Xue   Shi, Hongbin   Su, Qian   Fang, Liyun   Yu, Fei   Yang, Huijun   Sun, Shaomei   Wang, Xing   Zhou, Ming   Jia, Qiyu   Wang, Guolin   Song, Kun   Wu, Yuntang   Sun, Zhong   Niu, Kaijun  

    Previous studies have supported the theory that there is a positive association between ferritin and carotid atherosclerosis in Western people. Diet plays an important role in determining serum ferritin concentration. Asian dietary patterns are different from Western dietary patterns, implying that there may be a difference in the association of ferritin with carotid atherosclerosis between Asian and Western people. However, few studies focus on the association between ferritin and carotid atherosclerosis among Asians. The aim of this study was to investigate how serum ferritin levels are associated with carotid atherosclerosis in an Asian adult population. A cross-sectional assessment was performed in 8302 adults in Tianjin, China. Carotid intima-media thickness (IMT) and plaques were assessed using ultrasonography, and serum ferritin was measured using the protein chip-chemiluminescence method. Multiple logistic regression analysis was used to examine the association between quartiles of serum ferritin concentration and carotid atherosclerosis. In the present study, the overall prevalence of IMT and carotid plaques in participants is 29.2 and 22.7%, respectively. In women, after adjustments for potentially confounding factors, the OR of IMT and carotid plaques by increasing serum ferritin quartiles were 1.00, 1.39 (95% CI 0.98-1.99), 1.39 (95% CI 0.99-1.97), 1.81 (95% CI 1.30-2.55) (P-for (trend)< 0.001) and 1.00, 1.24 (95% CI 0.89-1.73), 1.18 (95% CI 0.85-1.65), 1.59 (95% CI 1.15-2.20) (Pfor trend< 0.01), respectively. However, no association was found between serum ferritin and carotid atherosclerosis in men. The study demonstrated that increased serum ferritin levels are independently associated with IMT and carotid plaques in Asian women but not in Asian men.
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  • A review of loop heat pipes for aircraft anti-icing applications

    Su, Qian   Chang, Shinan   Zhao, Yuanyuan   Zheng, Haikun   Dang, Chaobin  

    Loop heat pipes (LHPs) are highly efficient two-phase heat transfer devices with the ability to transport significant amounts of heat over long distances. Owing to the increasing demand of anti-icing applications in aircraft, certain investigations regarding LHP anti-icing have been successfully conducted, which verified the anti-icing capacity and feasibility of loop heat pipe ice protection system (LHPIPS). In this work, we will conduct a deep analysis on the LHP application to aircraft anti-icing. After a brief introduction of the historical application background and application environment of the LHPIPS, a detailed description of its fundamental design will be elucidated, followed by a series of optimization strategies, including the graphene-coating integration technology, the adoption of bidisperse wicks, the introduction of nanofluids, and the use of double compensation chamber loop heat pipe (DCCLHP). We present the additional points that require further study and that could be further optimized for the development of the LHPIPS. This work contributes to a thorough understanding of the novel and promising LHPIPS, as well as guides its future designs and applications. (C) 2017 Elsevier Ltd. All rights reserved.
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  • An experimental study on the heat transfer performance of a loop heat pipe system with ethanol-water mixture as working fluid for aircraft anti-icing

    Su, Qian   Chang, Shinan   Song, Mengjie   Zhao, Yuanyuan   Dang, Chaobin  

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  • Extracellular expression of a novel ss-agarase from Microbulbifer sp Q7,isolated from the gut of sea cucumber

    Su, Qian   Jin, Tianyi   Yu, Yuan   Yang, Min   Mou, Haijin   Li, Li  

    A novel endo-type ss-agarase was cloned from an agar-degrading bacterium, Microbulbifer sp. Q7 (CGMCC No. 14061), that was isolated from sea cucumber gut. The agarase-encoding gene, ID2563, consisted of 1800 bp that encoded a 599-residue protein with a signal peptide of 19 amino acids. Sequence analysis suggested that the agarase belongs to the GH16 family. The agarase was expressed in Escherichia coli with a total activity of 4.99 U/mL in fermentation medium. The extracellular enzyme activity accounted for 65.73% of the total activity, which indicated that the agarase can be extracellularly secreted using the wild-type signal peptide from Microbulbifer sp. Q7. The agarase exhibited maximal activity at approximately 40 degrees C and pH 6.0. It was stable between pH 6.0 and pH 9.0, which was a much wider range than most of the reported agarases. The agarase was sensitive to some metal ions (Cu2+, Zn2+ and Fe3+), but was resistant to urea and SDS. The agarase hydrolyzed ss-1,4-glycosidic linkages of agarose, primarily yielding neoagarotetraose and neoagarohexaose as the final products. These indicate that this recombinant agarase can be an effective tool for the preparing functional neoagaro-oligosaccharides.
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  • Hypoxia stimulates proliferation of rat neural stem/progenitor cells by regulating mir-21:an in vitro study

    Chen, Rui   Liu, Yanmei   Su, Qian   Yang, Yang   Wang, Li   Ma, Shuyun   Yan, Jiajia   Xue, Fangfang   Wang, Jianjun  

    Neural stem/progenitor cells (NSPCs) reside not only in the developing brain, but also in the adult brain within specialized microenvironments that regulate their function. In vitro and in vivo studies have revealed strong regulatory links between hypoxic/ischemic insults and activation of NSCPs. However, the underlying mechanisms of this activation remain unclear. In this study, we found that cell proliferation is promoted by hypoxia, and accompanied by increasing expression of miR-21 in cultured rat NSPCs. Moreover, qRT-PCR analysis indicated that expression of miR-21 increases in a time-dependent manner. 5-Bromo-2-deoxyUridine (BrdU) staining and flow cytometry showed that overexpression of miR-21 further promoted proliferation of NSPCs in the presence of hypoxia. Knocking down of miR-21 partially abolished the proliferative effect of hypoxia treatment on cell proliferation. Western blot demonstrated that overexpression of miR-21 enhanced expression of cyclin D1, while knock down of miR-21 suppressed cyclin D1 expression under hypoxic conditions. Furthermore, overexpression of miR-21 also increased levels of p-AKT. These results demonstrate that miR-21 plays a role in regulating the proliferation of cultured rat NSPCs undergoing hypoxia, and the activation of the PI-3-K signaling pathway might be one of the underlying mechanisms. These findings prompt a molecular study investigating potential mechanisms for stem cell treatment of cerebral ischemia.
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  • The Impact and Mechanism of Methylated Metabotropic Glutamate Receptors 1 and 5 in the Hippocampus on Depression-Like Behavior in Prenatal Stress Offspring Rats

    Lin, Tianwei   Dang, Shaokang   Su, Qian   Zhang, Huiping   Zhang, Junli   Zhang, Lin   Zhang, Xiaoxiao   Lu, Yong   Li, Hui   Zhu, Zhongliang  

    An increasing number of epidemiological investigations and animal models research suggest that prenatal stress (PS) could cause depression-like behavior in the offspring, which is sex specific. However, the underlying mechanisms remain to be elucidated. This study is to investigate the promoter methylation of metabotropic glutamate receptor 1 (mGluR1) and metabotropic Glutamate Receptor 5 (mGluR5) gene modification on PS induced depression-like behavior in offspring rats (OR). PS models were established, with or without 5-aza-2-deoxycytidine (5-azaD, decitabine) treatment. Animal behavior was assessed by the sucrose preference test (SPT), forced swimming test (FST), and open field test (OFT). The mRNA and protein expression levels of mGluR1 and mGluR5 in the hippocampus of offspring were detected with quantitative real-time PCR and Western blot analysis, respectively. The promoter methylation in the hippocampus of mGluR1 and mGluR5 OR were also analyzed. SPT showed significantly reduced sucrose preference in PS induced OR. FST showed significantly prolonged immobility time in PS induced OR. OFT showed significantly reduced central residence time in PS induced OR and no significantly influence in rearing as well as in frequency of micturition. Moreover, the mRNA, protein expression levels, and gene promoter methylation level of mGluR1 and mGluR5 in the hippocampus were significantly increased in the PS induced male OR, while no significantly influence in the PS induced female OR. Furthermore, the PS induced effects in male OR could be reversed by the microinjection of 5-azaD. In conclusion, our results showed that the promoter methylation of mGluR1 and mGluR5 gene modification is only involved in PS induced depression-like behavior in male OR in a sex-specific manner. These findings might contribute to the understanding of the disease pathogenesis and clinical treatment in future.
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  • The association between immunoglobulin concentrations and prediabetes prevalence in a large Chinese cohort

    Wang, Honglei   Song, Yanqi   Sun, Shaomei   Gao, Li   Liu, Li   Meng, Ge   Wu, Hongmei   Xia, Yang   Bao, Xue   Gu, Yeqing   Shi, Hongbin   Su, Qian   Fang, Liyun   Yang, Huijun   Wang, Xing   Zhou, Ming   Jia, Qiyu   Song, Kun   Zhang, Qing   Niu, Kaijun  

    Aims. Prediabetes has received public attention owing to the increasing prevalence worldwide. Mounting evidence has indicated that inflammation directly contributed to the etiology of glucose metabolism disorders. Although immunoglobulins play a crucial role in immune responses, little research has been done on the link between immunoglobulins and prediabetes in adults. Hence, the aim of the present study was to explore the associations between immunoglobulins levels and prevalence of prediabetes in a general adult population. Methods. A cross-sectional study was conducted among 8856 adults (mean standard deviation age: 48.4 +/- 10.7 years) in Tianjin, China. The serum immunoglobulins concentrations were measured by the immunonephelometric technique. Prediabetes was diagnosed using the following parameters in accordance with the American Diabetes Association: fasting plasma glucose, postprandial glucose and glycosylated hemoglobin. The associations between concentrations of immunoglobulins and the prevalence of prediabetes were assessed using multiple logistic regression models. Results. Overall, the prevalence of prediabetes was 37.4% (3311/8856). After controlling for confounders, compared with the lowest quintile, the odds ratios (95% confidence interval) of prediabetes for the highest quintile of immunoglobulins (immunoglobulin G, immunoglobulin E, immunoglobulin M and immunoglobulin A) were as follows: 1.06 (0.91-1.23), 1.31 (1.13-1.52), 0.86 (0.74-1.01), and 1.19 (1.03-1.38) (P for trend were 0.35, <0.0001, 0.04 and 0.02), respectively. Conclusions. Elevated immunoglobulin E and immunoglobulin A levels were independently and positively associated with prediabetes prevalence. There was also a trending association between immunoglobulin M concentrations and prediabetes prevalence. Further studies are necessary to clarify if there is a causal association of immunoglobulins in prediabetes or if they reflect early immunologic disturbances in these patients. 2017 Elsevier Inc. All rights reserved.
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