oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 56 )

2018 ( 575 )

2017 ( 558 )

2016 ( 536 )

Custom range...

Search Results: 1 - 10 of 47855 matches for " FAN Chun-zhi "
All listed articles are free for downloading (OA Articles)
Page 1 /47855
Display every page Item
THE MATRIX ANALYSIS OF ROTATION TWINS

Li Chun-zhi,

金属学报 , 1978,
Abstract: Two transformation matrixes appropriated to describe the rotation of the crystallographic coordinate systems are proposed. The transformation matrixes for components of vector rotated about an arbitrary axis by any angle in crystal real space or reciprocal space are derived.
Investigation on Quantitative Structure Activity Relationships and Pharmacophore Modeling of a Series of mGluR2 Antagonists
Meng-Qi Zhang,Xiao-Le Zhang,Yan Li,Wen-Jia Fan,Yong-Hua Wang,Ming Hao,Shu-Wei Zhang,Chun-Zhi Ai
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12095999
Abstract: MGluR2 is G protein-coupled receptor that is targeted for diseases like anxiety, depression, Parkinson’s disease and schizophrenia. Herein, we report the three-dimensional quantitative structure–activity relationship (3D-QSAR) studies of a series of 1,3-dihydro-benzo[b][1,4]diazepin-2-one derivatives as mGluR2 antagonists. Two series of models using two different activities of the antagonists against rat mGluR2, which has been shown to be very similar to the human mGluR2, (activity I: inhibition of [ 3H]-LY354740; activity II: mGluR2 (1 S,3 R)-ACPD inhibition of forskolin stimulated cAMP.) were derived from datasets composed of 137 and 69 molecules respectively. For activity I study, the best predictive model obtained from CoMFA analysis yielded a Q 2 of 0.513, R 2 ncv of 0.868, R 2 pred = 0.876, while the CoMSIA model yielded a Q 2 of 0.450, R 2 ncv = 0.899, R 2 pred = 0.735. For activity II study, CoMFA model yielded statistics of Q 2 = 0.5, R 2 ncv = 0.715, R 2 pred = 0.723. These results prove the high predictability of the models. Furthermore, a combined analysis between the CoMFA, CoMSIA contour maps shows that: (1) Bulky substituents in R 7, R 3 and position A benefit activity I of the antagonists, but decrease it when projected in R 8 and position B; (2) Hydrophilic groups at position A and B increase both antagonistic activity I and II; (3) Electrostatic field plays an essential rule in the variance of activity II. In search for more potent mGluR2 antagonists, two pharmacophore models were developed separately for the two activities. The first model reveals six pharmacophoric features, namely an aromatic center, two hydrophobic centers, an H-donor atom, an H-acceptor atom and an H-donor site. The second model shares all features of the first one and has an additional acceptor site, a positive N and an aromatic center. These models can be used as guidance for the development of new mGluR2 antagonists of high activity and selectivity. This work is the first report on 3D-QSAR modeling of these mGluR2 antagonists. All the conclusions may lead to a better understanding of the mechanism of antagonism and be helpful in the design of new potent mGluR2 antagonists.
MicroRNA-221 and microRNA-222 regulate gastric carcinoma cell proliferation and radioresistance by targeting PTEN
Zhang Chun-zhi, Han Lei, Zhang An-ling, Fu Yan-chao, Yue Xiao, Wang Guang-xiu, Jia Zhi-fan, Pu Pei-yu, Zhang Qing-yu, Kang Chun-sheng
BMC Cancer , 2010, DOI: 10.1186/1471-2407-10-367
Abstract: The human gastric cancer cell line SGC7901 was transfected with AS-miR-221/222 or transduced with pMSCV-miR-221/222 to knockdown or restore expression of miR-221 and miR-222, respectively. The effects of miR-221 and miR-222 were then assessed by cell viability, cell cycle analysis, apoptosis, transwell, and clonogenic assay. Potential target genes were identified by Western blot and luciferase reporter assay.Upregulation of miR-221 and miR-222 induced the malignant phenotype of SGC7901 cells, whereas knockdown of miR-221 and miR-222 reversed this phenotype via induction of PTEN expression. In addition, knockdonwn of miR-221 and miR-222 inhibited cell growth and invasion and increased the radiosensitivity of SGC7901 cells. Notably, the seed sequence of miR-221 and miR-222 matched the 3'UTR of PTEN, and introducing a PTEN cDNA without the 3'UTR into SGC7901 cells abrogated the miR-221 and miR-222-induced malignant phenotype. PTEN-3'UTR luciferase reporter assay confirmed PTEN as a direct target of miR-221 and miR-222.These results demonstrate that miR-221 and miR-222 regulate radiosensitivity, and cell growth and invasion of SGC7901 cells, possibly via direct modulation of PTEN expression. Our study suggests that inhibition of miR-221 and miR-222 might form a novel therapeutic strategy for human gastric cancer.Gastric cancer, a highly invasive and aggressive malignancy that is characterized by resistance to apoptosis and radioresistance, is among the most common cancers and is the leading cause of cancer-related death in China [1-6]. Gastric cancer in China is often diagnosed at an advanced clinical stage, with evident lymphatic tumor dissemination [4]. The 5-year survival rate is approximately 60% for patients with localized disease, but only 2% for those with metastatic disease[7]. Although much has been learned about the genetic and biochemical bases of gastric cancer, few novel therapeutic targets have been identified, due to difficulties in target identification
A USEFUL METHOD FOR INDEXING ELECTRON DIFFRACTION PATTERNS
电子衍射谱分析中的一种有效方法

LI CHUN-ZHI,
李春志

物理学报 , 1979,
Abstract: In this paper, general expressions for coordinate transformation in crystal direct space or reciprocal space are derived by using of matrix calculus. A matrix method for indexing complex electron diffraction patterns of two phase structures, twins and high order Laue zones is described.
MiR-221 and miR-222 target PUMA to induce cell survival in glioblastoma
Chun-Zhi Zhang, Jun-Xia Zhang, An-Ling Zhang, Zhen-Dong Shi, Lei Han, Zhi-Fan Jia, Wei-Dong Yang, Guang-Xiu Wang, Tao Jiang, Yong-Ping You, Pei-Yu Pu, Jin-Quan Cheng, Chun-Sheng Kang
Molecular Cancer , 2010, DOI: 10.1186/1476-4598-9-229
Abstract: Here we showed that miR-221/222 inhibited cell apoptosis by targeting pro-apoptotic gene PUMA in human glioma cells. Enforced expression of miR-22/222 induced cell survival whereas knockdown of miR-221/222 rendered cells to apoptosis. Further, miR-221/222 reduced PUMA protein levels by targeting PUMA-3'UTR. Introducing PUMA cDNA without 3'UTR abrogated miR-221/222-induced cell survival. Notably, knockdown of miR-221/222 induces PUMA expression and cell apoptosis and considerably decreases tumor growth in xenograft model. Finally, there was an inverse relationship between PUMA and miR-221/222 expression in glioma tissues.To our knowledge, these data indicate for the first time that miR-221/222 directly regulate apoptosis by targeting PUMA in glioblastoma and that miR-221/222 could be potential therapeutic targets for glioblastoma intervention.MicroRNAs (miRNAs), a new class of small RNA (~22nt), are thought to negatively regulate protein-coding genes by base-pair matching with 3'UTR of mRNA. Growing evidence has indicated that the important roles for miRNAs in the development of different cancers. Deregulation of miRNAs has been observed in various types of human malignancy, including lymphoma, colorectal cancer, lung cancer, breast cancer, papillary thyroid carcinoma, hepatocellular carcinoma and glioblastoma [1-7]. And oncomiRs and tumor suppressor miRNAs exert their functions through regulation of tumor suppressor genes and oncogenes, respectively [8-10].Glioblastoma is one of the most common forms of neural malignancy, with a median survival of 9-12 months. Despite the significant toxicities of current therapies, a large fraction of brain cancer patients suffer tumor recurrence due to the resistance to chemo- and radio-therapy [11-13]. Thus, there are urgent needs to develop novel therapeutic approaches by targeting the molecules that are altered in this malignancy. Recent studies showed frequent deregulation of miR-221/222 in glioblastoma [1,14]. We profiled miR
Quantitative measurement of the elastic modulus of the biceps brachii during muscle relaxation and tension by shear-wave elasto-sonography
实时定量超声弹性成像技术检测肱二头肌松弛和紧张状态下弹性模量值差异

WEN Chao-yang,FAN Chun-zhi,AN Li-chun,XU Jian-hong,CHEN Hao,WANG Yue-xiang,TANG Jie,
温朝阳
,范春芝,安力春,徐建红,陈浩,王月香,唐杰

中华医学超声杂志(电子版) , 2011,
Abstract: Objective To explore the difference of Young' s modulus in the biceps brachii during muscle relaxation and tension. Methods A total of 141 healthy male volunteers with age range from 16 to 34 years ( mean 22 years old ) were included in the study. A shear-wave elasto-sonography ( AixPlorer model, Supersonic Imagine, Aix en Provence, France) coupled with a linear array transducer array (4-15 MHz) was used. The scanner was set at the SWE mode and then at Q-BOX mode and the ultrasound trans- ducer was placed directly above the biceps brachii belly and carefully aligned with the muscle bundle. The elastic moduli of the biceps brachii were measured during muscle relaxation and tension in all 141 volun- teers. Results The Young' s modulus of biceps brachii was 123. 658 ±31. 392 kPa during muscle tension and 45. 658 ± 13. 479 kPa during muscle relaxation, respectively with statistical significance (P = 0.0000), Conclusion The Young' s modulus of the biceps brachii was higher during muscle tension than those during muscle relaxation.
Influence of Doped Cu-Zn on Structure and Properties of TiN Films
WEI Chun-Bei,GONG Chun-Zhi,TIAN Xiu-Bo,YANG Shi-Qin
无机材料学报 , 2009, DOI: 10.3724/sp.j.1077.2009.01231
Abstract: Cu-Zn doped TiN films were fabricated on stainless steel by hybrid magnetron sputtering. Influences of Cu and Zn concentration on structure and properties (such as microhardness, wear resistance and corrosion resistance) of the films were investigated. The results indicate that growth of TiN grains is blocked by doped Cu and Zn and TiN grain size decreases with increasing Cu and Zn concentration. In contrast, high Cu and Zn content induces coarse structure due to the growth of copper grains. With Cu 0.38at% and Zn .19at%, the films show a preferred TiN(111) texture orientation, and TiN(200) orientation enhances with increasing the doped element content. XPS results show that the films are mainly composed of TiN and pure Cu. The composite film with co-doping 10.38at% Cu and 2.19at% Zn exhibits higher microhardness and wear resistance. The passivation potential is substantially improved with small amount of Cu-Zn although the corrosion resistance of the films decreases with increasing Cu and Zn concentration.
Interactions of a Charged Particle with Parallel Two-Dimensional Quantum Electron Gases

LI Chun-Zhi,SONG Yuan-Hong,WANG You-Nian,

中国物理快报 , 2008,
Abstract: By using the linearized quantum hydrodynamic (QHD) theory, electronic excitations induced by a charged particle moving between or over two parallel two-dimensional quantum electron gases (2DQEG) are investigated. The calculation shows that the influence of the quantum effects on the interaction process should be taken into account. Including the quantum statistical and quantum diffraction effects, the general expressions of the induced potential and the stopping power are obtained. Our simulation results indicate that a V-shaped oscillatory wake potential exists in the electron gases during the test charge intrusion. Meanwhile, double peaks will occur in the stopping power when the distance of two surfaces is smaller and the test charge gets closer to any one of the two sheets.
Homoepitaxial Growth and Optical Properties of ZnO Polar Nanoleaves
Local Homoepitaxial Growth and Optical Properties of ZnO Polar Nanoleaves

ZHANG Chun-Zhi,GAO Hong,ZHANG Di,ZHANG Xi-Tian,

中国物理快报 , 2008,
Abstract: Using a mixture of ZnO and Te powders as the source material, ZnO nanoleaves with high yield and uniform morphology are fabricated by thermal evaporation. Each nanoleaf is constructed with a nanowire and a nanodisc on one side of the nanowire near the top. The polygonal nanodisc is in symmetricdistribution in relation to the nanowires and has polar planes ±(0001) as surfaces. A local homoepitaxial growth mechanism of ZnO polar nanodiscs induced by Te is proposed. With thin nanodiscs, the ZnO nanoleaves could be used in nanolasers, sensors, and photoelectronic nanodevices. Room-temperature photoluminescence result implies good crystalline quality of the ZnO nanoleaves.
Independent component analysis based on whiten scatter difference matrix for expression recognition
白化散度差矩阵的独立元分析应用于表情识别*

LI Chun-zhi,CHEN Xiao-hua,
李春芝
,陈晓华

计算机应用研究 , 2011,
Abstract: As the traditional ICA does not consider the impornance of the independent components for classification and recognition.This paper proposed a method,which obtained scatter difference matrix by calculation of expression face matrix and neutral face matrix,abolished the total scatter matrix as a generation matrix which had been employed by 2DPCA.As a result,increased difference of between-class scatter,and weakened the noisy from the variety of face.Firstly this method whitened scatter difference matrix.Seco...
Page 1 /47855
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.