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Search Results: 1 - 10 of 300326 matches for " 尚姝环<br>LIU Xue-jiao "
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Effect of Wnt/β-catenin Signaling Pathway on Expressions of EMMPRIN/MMPs in Two Cell Culture Models

刘学姣, 张珍, 李成章, <br>LIU Xue-jiao, ZHANG Zhen, LI Cheng-zhang, SHANG Shu-huan
- , 2018, DOI: 10.13701/j.cnki.kqyxyj.2018.02.007
Abstract: 摘要 目的:用牙龈成纤维细胞(human gingival fibroblast,HGFs)单独培养、HGFs与人永生口腔上皮细胞(human immortalized oral epithelial cell,HIOEC)直接共培养模型探究wnt/β-catenin信号通路对基质金属蛋白酶诱导因子(EMMPRIN)、明胶酶(MMP-2、MMP-9)表达的影响。方法:细胞免疫荧光检测β-catenin的表达。使用wnt/β-catenin信号通路的抑制剂Dickkopf-1(DKK-1)和激活剂wnt3a分别作用于HGFs和共培养模型。蛋白印记法、实时荧光定量PCR、明胶酶谱法检测细胞内和培养基上清中相关指标的表达。结果:β-catenin在HIOEC中表达较HGFs多。当wnt/β-catenin信号通路被抑制时,EMMPRIN、MMP-2、MMP-9的表达增加(P<0.05),反之则减少(P<0.05)。共培养模型较HGFs单独培养对DKK-1和wnt3a的反应更敏感。结论:共培养模型是本实验较好的实验方法。激活wnt/β-catenin信号通路可有效抑制EMMPRIN、MMP-2、MMP-9的表达
Mobile user forecast and power-law acceleration invariance of scale-free networks

Guo Jin-Li,Guo Zhao-Hua,Liu Xue-Jiao,<br>
中国物理 B , 2011,
Abstract: This paper studies and predicts the number growth of China's mobile users by using the power-law regression. We find that the number growth of the mobile users follows a power law. Motivated by the data on the evolution of the mobile users, we consider scenarios of self-organization of accelerating growth networks into scale-free structures and propose a directed network model, in which the nodes grow following a power-law acceleration. The expressions for the transient and the stationary average degree distributions are obtained by using the Poisson process. This result shows that the model generates appropriate power-law connectivity distributions. Therefore, we find a power-law acceleration invariance of the scale-free networks. The numerical simulations of the models agree with the analytical results well.
Establishment and optimization of the conjugal transfer system of fostriecin producer Streptomyces pulveraceus
Fostriecin产生菌Streptomyces pulveraceus遗传转化体系的建立与优化

LIU Xue-Jiao,NIU Ming-Shan,QIU Rong-Guo,TANG Li,<br>刘雪娇,牛铭山,邱荣国,唐莉
微生物学通报 , 2012,
Abstract: Objective] Establishment and optimization of the gene transfer system of Streptomyces pulveraceus which produces fostriecin based on normal conjugal transfer method. Methods] Intergeneric genetic transfer system was based upon integrative plasmid pSET152 from donor E. coli ET12567/pUZ8002 to Streptomyces pulveraceus. Results] The maximum transformation efficiency of Streptomyces pulveraceus by conjugation was obtained when MS medium containing 15% glycine was used, with the spores heat-shocked at 50 °C for 10 min before mixing with E. coli, using a final 20 mg/L concentration of apramycin for overlay after incubation of 18 h. Simultaneity, pSET153::gfp was constructed from pSET152 by combining the constitutive ermE+ promoter with green fluorescent protein gene (gfp). Green fluorescent protein gene was expressed. Conclusion] In summary, intergeneric genetic transfer system was demonstrated and optimized, and glycin can increase the efficiency of exconjugates.
Kinetics of Endocrine Disrupting Chemical 4-tert-butylphenol During Chlorination in Aqua

SUN Xiao-feng,GAO Nai-yun,XU Bin,WANG Xue-jiao,NING Ran,LIU Sui-qing,<br>孙晓峰,高乃云,徐斌,汪雪姣,宁冉,刘隧庆
环境科学 , 2007,
Abstract: The kinetics of endocrine disruptor 4-tert-butylphenol by chlorination in aqua was studied. The results showed that 4-TBP was rapidly oxidized by chlorine with different initial concentrations of HOCl and pH, and second-order reaction kinetics was observed between 4-TBP and chlorine. The apparent kinetic rate constants were influenced by pH values, kapp reached its highest and lowest level at pH 5 and 9 respectively. The kinetic rate constant of every elementary reaction was calculated. The rate constants for the acid-catalyzed reaction and the reaction between between ClO- and4-TBP were 4.99×106 L2?mol-2?s-1 and 1.96×104L?(mol?s)-1 respectively. The reaction between HOCl and 4-TBP or HOCl and 4-TBP- was very slow, and ClO- did not react with 4-TBP-. 4-TBP was influenced by chlorine disinfection during water treatment. The corresponding half-life times was 12.1min when chlorine concentration was 3 mg/L.
Individual and Group Dynamics in Purchasing Activity
Lei Gao,Jin-Li Guo,Chao Fan,Xue-Jiao Liu
Computer Science , 2010, DOI: 10.1016/j.physa.2012.07.047
Abstract: As a major part of the daily operation in an enterprise, purchasing frequency is of constant change. Recent approaches on the human dynamics can provide some new insights into the economic behaviors of companies in the supply chain. This paper captures the attributes of creation times of purchase orders to an individual vendor, as well as to all vendors, and further investigates whether they have some kind of dynamics by applying logarithmic binning to the construction of distribution plot. It's found that the former displays a power-law distribution with approximate exponent 2.0, while the latter is fitted by a mixture distribution with both power-law and exponential characteristics. Obviously, two distinctive characteristics are presented for the interval time distribution from the perspective of individual dynamics and group dynamics. Actually, this mixing feature can be attributed to the fitting deviations as they are negligible for individual dynamics, but those of different vendors are cumulated and then lead to an exponential factor for group dynamics. To better describe the mechanism generating the heterogeneity of purchase order assignment process from the objective company to all its vendors, a model driven by product life cycle is introduced, and then the analytical distribution and the simulation result are obtained, which are in good line with the empirical data.
Method comparison for measurement of dissolved organic nitrogen in seawater using high temperature combustion and persulfate oxidation

YAN Xue-jiao,WANG Jiang-tao,<br>阎雪姣,王江涛
海洋科学 , 2012,
Abstract: Nitrogen is an important nutrition for halobios.As an important component of total dissolved nitrogen(TDN),dissolved organic nitrogen(DON) has been paid more and more attention.Now,essentially all routine methods measure total dissolved nitrogen(TDN) and calculate DON by subtracting the dissolved inorganic nitrogen(DIN).In this study,two common methods for determination of DON: persulfate oxidation(PO) and high temperature combustion(HTC) were compared.The results show that both methods have good agreements at blank,precision and accuracy.They also resulted in high recovery for various nitrogen-containing compounds(92%~107%) with a slope of 0.93 and 0.92,respectively,which indicates a high oxidation rate.The results of field samples showed the slope of section linear fit results is 0.92 and 0.97.So both methods had their own advantages,but HTC method is more efficient.
The application of the undetermined fundamental frequency for analyzing the critical value of chaos

Wang Wei,Zhang Qi-Chang,Wang Xue-Jiao,<br>王炜,张琪昌,王雪娇
物理学报 , 2009,
Abstract: The simple approach to improve the computational precision of Melnikov method is presented by using the undetermined fundamental frequency and normal form method. We construct the improved Melnikov expression for a triple-well nonlinear oscillator subject to principal parametric resonance and external excitation. For the occurrence of chaos, the approxime threshold values of chaotic motion are obtained from the Homoclinicity and Heteroclinicity points of view. It depends on the introduction of undetermined fundamental frequency, and adopting new time transformation for fulfilling the homoclinic and heteroclinic orbits, so that the effect of disturbing parameter can be easily detected and embodied in the Melnikov operation. As is illustrated, the explicit applications show that the improved results coincide very well with the results of numerical simulation.
Effects of Long-Term Exposure to Nonylphenol on Secondary Sexual Characteristics and Sperm Motility of Male Zebrafish (Brachydanio rerio)

XIA Ji-gang,NIU Cui-juan,GAO-Yng,PEI Xue-jiao,<br>夏继刚,牛翠娟,高颖,裴雪姣
生态毒理学报 , 2010,
Abstract: 研究了不同浓度下(0(对照)、0.1、1、10、100μg·L-1)壬基酚(NP)长期暴露对斑马鱼(Brachydanio rerio) 雄鱼第二性征、精子活力的影响. 结果表明,NP暴露对斑马鱼第二性征的影响显著,可导致雄性个体出现泄殖乳突、腹部膨大等典型雌性化特征. 100μg·L-1 NP暴露导致76.9%的雄鱼出现泄殖乳突. NP暴露对斑马鱼精子激活率的影响显著,随NP暴露浓度升高精子激活率下降,呈现负相关的剂量-效应关系. NP暴露对斑马鱼精子寿命和精子剧烈运动时间均有显著影响. 低剂量(0.1μg·L-1)和高剂量(100μg·L-1)NP暴露下精子寿命及其剧烈运动时间显著缩短,而中等剂量(10μg·L-1)NP对上述指标影响不显著(p>0.05). 斑马鱼第二性征、精子活力可作为指示水体环境雌激素毒理学效应的敏感指标.
Isolation and identification of a decabromodiphenyl ether degrading bacterium BD-24 and its degradation characteristics

CHEN Xue-jiao,JIN Dan-feng,DING Hai-tao,ZHAO Yu-hua,<br>陈雪娇,金丹凤,丁海涛,赵宇华
浙江大学学报(农业与生命科学版) , 2010,
Abstract: A bacterial strain BD-24,which was able to use decabromodiphenyl ether (BDE-209) as the sole carbon and energy source,was isolated from activated sludge in an oil refinery at Hangzhou,China by selective enrichment method .Based on morphological,physiological and biochemical characteristics,phylogenetic analysis of 16S rDNA gene sequence similarity,and (G + C) mol%,strain BD-24 was identified as Bacillussp . High performance liquid chromatograph analysis showed that the residue rate of BDE-209 (20 mg.L-1 ) in mineral medium decreased to75.1 % and65.6 % after the incubation of strain BD-24 for15 and25 days,respectively . Addition of second carbon sources generally enhanced the BDE-209 degradation by strain BD-24,especially in which maltose could result in 20 mg.L-1 of BDE-209 decreasing quickly to83.5 % within5 days . No active effect of different kinds of nitrogen sources on the BDE-209 biodegradation was observed .
Influencing Factors and Kinetics of Oxidation of Bisphenol A in Water with Sodium Hypochlorite

WANG Xue-jiao,GAO Nai-yun,SUN Xiao-feng,XU Bin,<br>汪雪姣,高乃云,孙晓峰,徐斌
环境科学 , 2007,
Abstract: The degradation and its kinetics of sodium hypochlorite oxidation of an endocrine disruptor-bisphenol A (BPA) were studied. The influencing factors were investigated, such as chlorine dosage, initial concentration of BPA, pH value, bromide ion concentration and temperature etc. The results showed that the degradation of BPA by sodium hypochlorite followed pseudo-first-order kinetics. The pH value influenced the degradation of BPA greatly. The pseudo-first-order rate constant of the reaction between BPA and HOCl reached the maximum value of 0.544 3 min(-1) during pH 8 - 9. Moreover, the bromine ion in water would accelerate the degradation of BPA, and the whole reaction did not follow the rule of pseudo-first-order kinetics. The temperature influenced the reaction greatly, and it followed Van' t Hoff Rule. The removal efficiency of BPA would increase with increasing temperature.
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