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Aggregating Properties of Compounds Cz-C-n in DMSO-H_2O Binary Solvent

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Chinese Chemical Letters 2002年第2期13卷 171-174页

作者： Jiu Yan li li Zhu WU li ping zhang Bo Jie WANG Chen Ho TUNG Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100101

The aggregating properties of Cz-C-n (n = 3, 6, 10) have been investigated by means of fluorescence method in DMSO-H2O binary solvent. The measured CAC and C F values indicate that the aggregating tendency of the amphiphilic compounds Cz-C-n containing crown ether increases with the length of alkyl chains, similar to that of carbazole compounds with long alkyl chains.

关键词： Aggregate fluorescence method amphiphilic compounds Cz-C-n crown ether.

RNA interference of pax2 inhibits growth of transplanted human endometrial cancer cells in nude mice

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Chinese Journal of Cancer 2011年第6期30卷 400-406页

作者： li-ping zhang Xiao-Yan Shi Chang-Yin Zhao Yong-Zhen liu ping Cheng Department of Gynecology and Obstetrics Taihe Hospital Hubei Medical University Shiyan Hubei 442000 P. R. China Central Laboratory Central Hospital of Wuhan Tongji Medical College Huazhong University of Science and Technology Wuhan Hubei 430014 P. R. China.

The development of human endometrial carcinoma(HEC) is a complex pathologic process involves several oncogenes and tumor suppressor *** full-length paired-box gene 2(pax2),a recently discovered oncogene,promotes cell proliferation and growth and inhibits apoptosis of HEC ***,we examined the effect of pax2 small interfering RNA(siRNA) on the growth of transplanted HEC cells in nude *** expression of Pax2 in 21 cases of normal endometrium and 38 cases of HEC was examined by immohistochemistry(IHC).HEC models were developed by subcutaneously transferring HEC cells into nude mice,followed by treatment with empty lentivirus vector,lentivirus vector-based pax2 siRNA,and phosphate buffered saline,*** weeks later,tumor size was measured,tumor inhibition rate was calculated,and histological analyses were conducted after staining with hematoxylin and *** expression of Pax2 and Bcl-2 was detected by Western blot;proliferating cell nuclear antigen(PCNA) was detected by *** differences were observed in the positive rate of Pax2 between normal endometrium and HEC(14.2% vs.60.5%,Plia stain decreased,tumor growth was inhibited,and PCNA,Pax2,and Bcl-2 expression was reduced in HEC models treated with pax2 *** results indicate that Pax2 expression is related to HEC tumor biology with the increased expression of Pax2 correlated to ***2 siRNA down-regulates Pax2 expression and inhibits tumorigenesis of HEC in nude mice,possibly due to cell apoptosis and the inhibition of tumor proliferation induced by down-regulation of Bcl-2.

关键词： siRNA 子宫内膜癌小干扰RNA 肿瘤生长细胞移植癌细胞裸鼠免疫组化检测

Unveiling the critical role of TiO_(2)-supported atomically dispersed Cu species for enhanced photofixation of N_(2)to nitrate

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Fundamental Research 2024年第4期4卷 934-940页

作者： Dong li Yunxuan Zhao Chao Zhou li-ping zhang Junwang Tang Tierui zhang Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBejing 100190China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBejing 100049China School of Future Technology University of Chinese Academy of SciencesBejing 100049China Department of Chemical Engineering University College LondonLondon WC1E7JEUnited Kingdom

Nitrate products are widely used in manufacturing as crucial raw materials and *** traditional nitrate synthesis process involves high energy consumption and emission,thereby opposing the goals of zero-carbon emission and green ***,a sustainable roadmap for nitrate synthesis that uses green energy input,clean N sources,and direct catalytic processes is urgently required(e.g.,developing a novel photosynthesis system).Here,we synthesized TiO2-supported atomically dispersed Cu species for N_(2)photofixation to nitrate in a flow *** optimized photocatalyst yielded a high nitrate photosynthesis rate of 0.93μmol h-1 and selectivity of~90%,which is superior to most of the values reported thus ***,experimental results and in-situ investigations revealed that the atomically dispersed Cu sites in the as-designed sample significantly enhanced the separation and transfer efficiency of photogenerated carriers,adsorption and activation of reactants,and the formation of chemisorbed O_(x)intermediates,thereby realizing the excellent photofixation of N_(2)to nitrate.

关键词： N_(2) photofixation TiO_(2) Nitrate photosynthesis Cu species NO_(x),intermediates

Changes of brain neuropeptide Y and its receptors in rats with flurazepam tolerance and dependence

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Acta Pharmacologica Sinica 2005年第11期26卷 1290-1296页

作者： li-ping zhang, li WANG~2 Department of Pediatrics, Peking University First Hospital, Beijing 100034, China Department of Pediatrics Peking University First Hospital Beijing China

Aim: Anticonvulsant tolerance and dependence are two obstacles that restrict the clinical use of benzodiazepines (BDZ). In order to explore the mechanism of these two adverse reactions, changes of neuropeptide Y (NPY) and its receptors in the hippocampus of rat models, in relation to flurazepam (FZP, a member of BDZ) tolerance and dependence, were investigated. Methods: The mRNA of preproNPY and its receptors (Y1, Y2, and Y5) in the hippocampus were determined by competitive RT-PCR, and the distribution of NPY in the hippocampus was examined by immunohistochemistry. Results: A decrease of preproNPY mRNA in the hippocampus was found in tolerant and dependent rats. The level of preproNPY mRNA in the hippocampus was reversely correlated with the degree of tolerance and dependence, measured by the threshold of pentylenetetrazol-induced seizures. Immunohistochemistry indicated a decrease of NPY-immunoreactive material in neurons of the CA1, CA3, and dentate gyrus regions of both tolerant and dependent rats. The mRNA of NPY receptors Y,and Y5decreased in tolerant rats but did not change in dependent rats. The mRNA of NPY receptor Y2increased in tolerant rats but decreased in dependent rats. Conclusion: A decrease of NPY in the hippocampus might be involved in anticonvulsant tolerance and dependence following long-term treatment with FZP. Y,, Y2, and Y5mRNA were also altered in FZP tolerance and dependence.

关键词： benzodiazepines neuropeptide Y flura zepam

Ratcheting Behavior of SA508-3 Steel at Elevated Temperature:Experimental Observation and Simulation

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Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 822-828页

作者： Jun Tian Yu Yang li-ping zhang Xue-Jiao Shao Juan Du Qian-Hua Kan Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiaotong University

A series of monotonic uniaxial tensile tests, strain-controlled and stress-controlled cyclic tests of SA508-3 steel were conducted from 25 to 350℃. Results showed that the steel exhibited temperature-dependent cyclic softening characteristic and obvious ratcheting behavior, and dynamic strain aging was observed in the range of 250-350℃. Based on experimental observations, a temperature-dependent cyclic plastic constitutive model was proposed by introducing the nonlinear cyclic softening and kinematic hardening rules, and the dynamic strain aging was also considered into the constitutive model. Comparisons between experiments and simulations were carded out to validate the proposed model at elevated temperature.

关键词： Ratcheting Constitutive model Dynamic strain aging Cyclic loading Elevated temperature

Accession-specific flowering time variation in response to nitrate fluctuation in Arabidopsis thaliana

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Plant Diversity 2021年第1期43卷 78-85页

作者： Fei-Hong Yan li-ping zhang Fang Cheng Dong-Mei Yu Jin-Yong Hu CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming650201China University of Chinese Academy of Sciences Beijing100049China

Flowering time,a key transition point from vegetative to reproductive growth,is regulated by an intrinsic complex of endogenous and exogenous signals including nutrient *** hundreds of years,nitrogen has been well known to modulate flowering time,but the molecular genetic basis on how plants adapt to ever-changing nitrogen availability remains not fully *** we explore how Arabidopsis natural variation in flowering time responds to nitrate *** nitrate availability change,we detect accession-and photoperiod-specific flowering responses,which also feature a accession-specific dependency on growth *** flowering time variation correlates well with the expression of floral integrators,SOC1 and FT,in an accession-specific *** find that gene expression variation of key hub genes in the photoperiod-circadian-clock(GI),aging(SPLs)and autonomous(FLC)pathways associates with the expression change of these integrators,hence flowering time *** results thus shed light on the molecular genetic mechanisms on regulation of accession-and photoperiod-specific flowering time variation in response to nitrate availability.

关键词： Nitrate Arabidopsis thaliana Photoperiod Natural variation Flowering time Gene expression

Application of collagen-chitosan/fibrin glue asymmetric scaffolds in skin tissue engineering

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第7期11卷 524-530页

作者： Chun-mao HAN li-ping zhang Jin-zhang SUN Hai-fei SHI Jie ZHOU Chang-you GAO Department of Burn the Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310009 China Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China

To create a scaffold that is suitable for the construction of tissue-engineered skin, a novel asymmetric porous scaffold with different pore sizes on either side was prepared by combining a collagen-chitosan porous membrane with fibrin glue. Tissue-engineered skin was fabricated using this asymmetric scaffold, fibroblasts, and a human keratinocyte line (HaCaT). Epidermal cells could be seen growing easily and achieved confluence on the fibrin glue on the upper surface of the scaffold. Scanning electron microscopy showed typical shuttle-like fibroblasts adhering to the wall of the scaffold and fluorescence microscopy showed them growing in the dermal layer of the scaffold. The constructed composite skin substitute had a histological structure similar to that of normal skin tissue after three weeks of culture. The results of our study suggest that the asymmetric scaffold is a promising biologically functional material for skin tissue engineering, with prospects for clinical applications.

关键词： Collagen Chitosan Fibrin glue Scaffold Tissue-engineered skin

Drag reduction and shear resistance properties of ionomer and hydrogen bond systems based on lauryl methacrylate

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Petroleum Science 2011年第3期8卷 357-364页

作者： Yu ping li Changyu zhang Changqiao Chen Shiwei Fang Shu Sun Hui School of Chemistry and Chemical Engineering Shandong University Jinan 250061 China

Based on molecular dynamics simulation results, a lauryl methacrylate polymer with drag reduction and shear resistance properties was designed, and synthesized by emulsion polymerization using 2-vinyl pyridine and methyl methacrylate as the polar polymerization monomer. After ionization of lauryl methacrylate polymer, an ion-dipole interaction based drag reduction agent （DRA） was obtained. The existence of ion-dipole interaction was proven through characterization of the drag-reducing agent from its infrared （IR） spectrum. The pilot-scale reaction yield of the DRA under optimum conditions was investigated, and the drag reduction and shear resistance properties were measured. The results show that： l） The ion-dipole or hydrogen bonding interaction can form ladder-shaped chains, therefore the synthesized DRA has shear resistance properties; 2） The larger the molecular weight （MW） and more concentrated the distribution of MW, the better the drag reduction efficiency and the performance of the ionomer system was superior to that of the hydrogen bonding system; 3） With increasing shear frequency, the drag-reduction rates of both the DRAs decreased, and the drag reduction rate of the ionomer system decreased more slowly than of the corresponding hydrogen bonding system. From the point of view of drag reduction rate and shear resistance property, the ionomer system is more promising than the hydrogen bonding system

关键词： Molecular design ion-dipole interaction hydrogen bonding drag reduction rate shearresistance property

Reevaluation of thermonuclear reaction rate of ^(50)Fe(p,γ)^(51)Co

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Chinese Physics C 2016年第12期40卷 113-119页

作者： li-ping zhang Jian-Jun He Wan-Dong Chai Su-Qing Hou li-Yong zhang College of Physics and Electronic Information Engineering Chifeng University Chifeng 024000 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Institute of Modern Physics Chinese Academy of Sciences

The thermonuclear rate of the 50Fe（p, γ）51Co reaction in the Type I X-ray bursts （XRBs） temperature range has been reevaluated based on a recent precise mass measurement at CSRe Lanzhou, where the proton separa- tion energy Sp=142±77 keV has been determined firstly for the ~1Co nucleus. Comparing to the previous theoretical predictions, the experimental Sp value has much smaller uncertainty. Based on the nuclear shell model and mirror nuclear structure information, we have calculated two sets of thermonuclear rates for the 50Fe（p, γ）51Coreaction by utilizing the experimental Sp value. It shows that the statistical-model calculations are not ideally applicable for this reaction primarily because of the low density of low-lying excited states in 51Co. In this work, we recommend that a set of new reaction rates based on the mirror structure of 51Cr should be incorporated in future astrophysical network calculations.

关键词： X-ray burst (XRB) nucleosynthesis mass measurement proton separation energy reaction rate