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Search Results: 1 - 10 of 75153 matches for " XU Qi-zhi "
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Empirical Research on Repo Rates Based on Exponenti- al Smooth Transition Autoregressive Model  [PDF]
Qi-zhi He
Journal of Service Science and Management (JSSM) , 2008, DOI: 10.4236/jssm.2008.11007
Abstract: In the process of China's marketization of interest rates, researching the characteristics of interest rates has very important theoretical and practical significance. Based on Chinese interbank repo interest rates, the characteristics of daily interest rates and monthly interest rates and their spreads have been researched, and unit root tests are paid to the level, the first difference and the spread of daily interest rates and monthly interest rates based on the traditional method and the exponential smooth transition autoregressive method (ESTAR) respectively. The results show: Firstly, as for different term of repo interest rates, the characteristics are different. Secondly, both lists of daily rates and monthly rates are integrated of order 1. Thirdly, the spread of daily interest rates and monthly interest rates is not stationary by use of ADF, but stationary by use of ESTAR. Finally, the long-run equilibrium relationship between daily repo interest rates and monthly repo interest rates is stable with nonlinear adjustment.
Dynamic threshold selection based on local region in edge detection

WANG Ji,LI Bo,XU Qi-zhi,

计算机应用研究 , 2010,
Abstract: Most of the current edge detection methods adopt global threshold selection techniques. However, global threshold selection sometimes is not adaptive to detect out important edges, whose gradient intensity are below it. In recent years, local threshold selection methods has developed, but the investigation is still insufficient and complicated to apply. Thus, in order to solve these problems,this paper proposed a method of dynamic threshold selection based on local region: each candidate edge point had two thresholds in local square region,where the point was in the center. Comparing the gradient of the edge point with the threshold, edge points can be picked out successfully. Experiments show that dynamic threshold selection has better results and little influence from noise than global thresholds selection used in Canny algorithm.
High MUC2 Expression in Ovarian Cancer Is Inversely Associated with the M1/M2 Ratio of Tumor-Associated Macrophages and Patient Survival Time
Yi-feng He, Mei-ying Zhang, Xin Wu, Xiang-jun Sun, Ting Xu, Qi-zhi He, Wen Di
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0079769
Abstract: Mucin 2 (MUC2) is a mucin molecule aberrantly expressed by ovarian cancer cells. Previous in vitro studies have indicated that MUC2 promotes cancer growth and metastasis through a tumor-associated macrophage (TAM)-dependent mechanism. However, this mechanism has never been linked to clinical oncology, and its prognostic significance needed to be clarified. Here, we collected 102 consecutive ovarian cancer specimens and used the multiple immuno-histo-chemical/-fluorescent technique to determine the correlations between the MUC2 expression status, the ratio of M1/M2 TAMs and the densities of cyclooxygenase-2 (COX-2)+ TAMs and COX-2+ cancer cells. The Kaplan-Meier survival analysis and multivariate Cox regression analysis were used to evaluate the prognostic influences of these parameters. As a result, we found that the MUC2 overexpression (immunostaining ++/+++) was significantly correlated with a reduced ratio of M1/M2 TAMs (p<0.001), an increased density of COX-2+ TAMs (p<0.001) and an increased density of COX-2+ cancer cells (p=0.017). Moreover, most of the M2 TAMs (93%-100%) and COX-2+ TAMs (63%-89%) overlapped; and the COX-2+ cancer cells were frequently observed near the COX-2+ TAMs. In the Cox regression analysis, MUC2 overexpression was found to be an independent prognostic factor for ovarian cancer patients, of which the hazard ratio (HR) was 2.354 (95% confidence interval (CI): 1.031-10.707, p=0.005). Also, the reduced ratio of M1/M2 TAMs and the increased densities of COX-2+ TAMs and COX-2+ cancer cells were demonstrated to be the predictors of poor prognosis, among which the reduced M1/M2 ratio possessed the highest HR (1.767, 95% CI: 1.061-6.957, p=0.019). All these findings revealed that MUC2 can concurrently exert M2-polarizing and COX-2-inducing effects on TAMs, by which it causes an imbalanced TAM M1-/M2-polarization pattern and induces local PGE2 synthesis (in both TAMs and cancer cells). The positive feedback between local PGE2 synthesis and TAM M2-polarization accelerates ovarian cancer progression.
The Product Method of Analytic Network Process

LIU Qi-zhi,

系统工程理论与实践 , 2004,
Abstract: In this paper a new decision method for analytic network process is proposed. In the method the concepts of directed graph and related matrix is used. It is proved that the method is expanded from Product AHP(in the method when synthesizing hierarchy results,product not sum is used) and can deal with general network structured problem.
Performance of a dipstick dye immunoassay for rapid screening of Schistosoma japonicum infection in areas of low endemicity
Jing Xu, Ting Feng, Dan-Dan Lin, Qi-Zhi Wang, Li Tang, Xiao-Hua Wu, Jia-Gang Guo, Rosanna W Peeling, Xiao-Nong Zhou
Parasites & Vectors , 2011, DOI: 10.1186/1756-3305-4-87
Abstract: 6285 individuals aged 6-65 years old participated in this study, with a prevalence of schistosomiasis of 4.20%. Using stool examination as a gold reference standard, DDIA performed with a high overall sensitivity of 91.29% (95% CI: 87.89-94.69%) and also a high negative predictive value, with a mean value of 99.29% (95% CI: 98.99-99.58%). The specificity of DDIA was only moderate (53.08%, 95% CI: 51.82-54.34%). Multivariate analysis indicated that age, occupation and history of schistosome infection were significantly associated with the false positive results of DDIA.DDIA is a sensitive, rapid, simple and portable diagnostic assay and can be used as a primary approach for screening schistosome infection in areas of low endemicity. However, more sensitive and specific confirmatory assays need to be developed and combined with DDIA for targeting chemotherapy accurately.Schistosomiasis japonica is one serious infectious disease, draining the economic and social development in the People's Republic of China (P.R. China) [1]. An estimated 100 million people were at risk of contracting schistosomiasis and 11.6 million were infected in 12 endemic provinces in P.R. China in the mid 20th century [1,2]. With continuous national programs being implemented in P.R. China, great achievements have been made in the control of schistosomiasis. The prevalence and intensity of Schistosoma japonicum (S. japonicum) infection have decreased dramatically. Most counties have reached the criteria of infection control (human prevalence less than 5% ), while in many others, transmission control (human prevalence less than 1%) or even transmission interruption (no case found in five consecutive years) has been achieved [3]. These different endemic levels increase the demand of sensitive and cost-effective diagnosis for accurate identification of schistosomiasis cases, followed by treatment of individuals and/or communities, and evaluation of intervention efficacy as the control goal is still
糖基化终末产物对小鼠骨髓间充质干细胞增殖及相关基因P27、cyclinD1 的影响
Effects of Advanced Glycation End Products on the Proliferation of Mouse Bone Marrow Mesenchymal Stem Cells and Expression of P27 and Cyclin D1

SUN Chuan-feng
, DENG Chao, YIN Qi-zhi, LIU Hai, ZHOU Song-lin, XU Qing

- , 2015,
Abstract: 摘要 目的:探讨糖基化终末产物(AGEs)对小鼠骨髓间充质干细胞(BMSCs)增殖能力以及相关基因P27、cyclinD1的影响。方法:全骨髓法培养小鼠骨髓间充质干细胞;成骨、成脂诱导骨髓间充质细胞,对其进行干细胞鉴定;将培养出的骨髓间充质干细胞与不同浓度的AGEs 共培养,MTT检测不同浓度下骨髓间充质干细胞增殖的改变;实时定量聚合酶链反应(Real time PCR)检测AGEs刺激后P27、cyclin D1表达的改变。结果:小鼠骨髓间充质干细胞成骨诱导21 d后茜素红染色出现钙化结节;成脂诱导21 d后油红O染色出现脂滴;MTT显示不同浓度的AGEs(10、50、100、200 mg/L)均能抑制BMSCs的增殖差异有统计学意义(P<0.05),且随着浓度的增加抑制越明显;Real time PCR结果显示:AGEs(50 mg/L)刺激3 d后P27 mRNA的表达水平较对照组升高,cyclinD1 mRNA的表达水平较对照组降低,差异有统计学意义(P<0.05)。结论:AGEs能抑制小鼠骨髓间充质干细胞的增殖并能改变P27 、cyclinD1 mRNA的表达
Time-Varying Sliding Mode Adaptive Control for Rotary Drilling System
Lin Li,Qi-zhi Zhang,Nurzat Rasol
Journal of Computers , 2011, DOI: 10.4304/jcp.6.3.564-570
Abstract: This paper presents a time-varying sliding mode adaptive controller in order to handle the stick-slip oscillation of nonlinear rotary drilling system. The time-varying sliding mode controller with strong robust has two time-varying sliding surfaces, one of them induced time-varying integral sliding mode control can control the transient stage of the rotary drilling system and ensure the system remains the sliding condition whatever in usual or existing the parameter changes and disturbances to arrive at a controller capable of global stability. The herein developed controller is, a time-varying sliding mode adaptive controller has tracking performance and identification of drilling parameters. Lyapunov principles have been carried out to verify the stability and robustness of system. The simulation results show that the controller has faster dynamic responses and suppress stick-slip in oil well drill string, can achieve global stability of rotary drilling system.
Tools to Support Policy Decisions Related to Treatment Strategies and Surveillance of Schistosomiasis Japonica towards Elimination
Xiao-Nong Zhou ,Jing Xu ,Hong-Gen Chen,Tian-Ping Wang,Xi-Bao Huang,Dan-Dan Lin,Qi-Zhi Wang,Li Tang,Jia-Gang Guo,Xiao-Hua Wu,Ting Feng,Jia-Xu Chen,Jian Guo,Shao-Hong Chen,Hao Li,Zhong-Dao Wu,Rosanna W. Peeling
PLOS Neglected Tropical Diseases , 2011, DOI: 10.1371/journal.pntd.0001408
Abstract: Background Appropriate diagnostics to monitor disease trends and assess the effectiveness and impact of interventions are essential for guiding treatment strategies at different thresholds of schistosomiasis transmission and for certifying elimination. Field validation of these assays is urgently needed before they can be adopted to support policy decisions of the national programme for control and elimination of schistosomiasis in P.R. China. We compared the efficacy and utility of different immunoassays in guiding control strategies and monitoring the endemic status of S. japonicum infections towards elimination. Methodology/Principal Findings A cross-sectional survey was conducted in seven villages with different transmission intensities settings to assess the performance and utility of three immunoassays, e.g., an indirect hemagglutination assay (IHA_JX), an enzyme linked immunosorbent assay (ELISA_SZ), and a dot immunogold filtration assay (DIGFA_SH). 6,248 individuals aged 6–65 years old who gave consent and supplied their stool and blood samples were included for data analysis. Results showed that ELISA_SZ performed significantly higher sensitivity (95.45%, 95%CI: 92.94–97.97%) than IHA_JX (87.59%, 95%CI: 83.51–91.49%) and DIGFA_SH (79.55%, 95%CI: 74.68–84.41%), especially in subgroups with very low infection intensity. The specificity of ELISA_SZ, IHA_JX, DIGFA_SH in 6–9 year olds with occasional exposure was nearly 90%. DIGFA_SH performed the highest screening efficacy for patients among three assays with overall positive predicative value of 13.07% (95%CI: 11.42–14.72%). We found a positive correlation of antibody positive rate of IHA_JX with results of stool examination in age strata (r = 0.70, P<0.001). Seropositivity of IHA_JX in children aged 6–9 years old showed an excellent correlation with prevalence of schistosome infection in the seven communities (r = 0.77, P<0.05). Conclusions/Significance Studies suggest that ELISA_SZ could be used to guide selective chemotherapy in moderate or low endemic regions. IHA_JX could be used to as a surveillance tool and for certifying elimination of schistosomiasis through monitoring children as a sentinel population.
Changes in Antioxidant Properties Induced by Heat Injury in Loquat Peel under High Temperature Stress

DENG Chao-jun,XU Qi-zhi,JIANG Ji-mou,WEI Xiu-qing,ZHANG Xi-juan,ZHENG Shao-quan,

热带亚热带植物学报 , 2012,
Abstract: 为探讨枇杷Eriobotrya japonica (Thunb.) Lindl.]对高温胁迫的响应,对‘红种’枇杷果皮热伤害的抗氧化特性进行研究。结果表明,在自然光下,枇杷果皮热伤害的阈值为40℃ (1.5 h),且果皮热伤害与温度和持续时间关系密切,光照可促进热伤害的发生。枇杷果皮受热伤害程度与果实本身的营养状态有关,果肉维生素C (Vc)、钙(Ca)含量越低, 果皮热伤害级数越高。与25℃相比,40℃高温处理增加了果皮的超氧阴离子和丙二醛(MDA)含量,而超氧化物歧化酶(SOD)、过氧化物酶(POD)的活性呈下降趋势。这揭示了高温胁迫下枇杷果皮对热伤害的抗氧化响应机制。


物理学报 , 1965,
Abstract: Using the familiar concepts of rotation group, we obtain the irreducible unitary representations and the reduction coefficients of the group SU3. (These coefficients may be called the generalized Clebsch-Gordan coefficients.) This method is easier than those given by other authors.
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