http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Protective Effects of Chalcone Derivatives for Acute Liver Injury in Mice
Li-Ping Guan,Ji-Xing Nan,Xue-Jun Jin,Qing-Hao Jin,곽경철,채규윤,Zhe-Shan Quan 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.1
The hepatoprotective effects of chalcone derivatives were evaluated in D-galactosamine/ lipopolysaccharide (D-GalN/LPS)-induced fulminant hepatic failure in mouse. Thirteen chalcone derivatives were synthesized for study and their hepatoprotective effects were evaluated by assessing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in serum. Chalcone preparations were injected into mice at 12 h and 1 h before intraperitoneal injection of D- GalN/LPS. After abdominal administration, changes in AST and ALT between the control and treated groups were observed. Ten of the synthesized chalcone derivatives exhibited inhibitory effects on D-GalN/LPS-induced levels of AST and ALT in mice. Compounds 2, 3, 8, 9, and 12 markedly reduced serum AST and ALT at 8 h, inhibited hepatocyte necrosis and showed significant hepatoprotective activities. The activity of compound 3 was compared with the bifendate (DDB) through oral administration. Compound 3 showed much higher inhibitory effects than bifendate for decreasing AST and ALT activity. The results indicate that compound 3 has strong hepatoprotective activity through suppression of tumor necrosis factoralpha (TNF-alpha) preduction, reduction of the histological change in the liver, and attenuated of hepatocyte apoptosis confirmed by DNA fragmentation assay.
Protective Effects of Chalcone Derivatives for Acute Liver Injury in Mice
Guan Li-Ping,Nan Ji-Xing,Jin Xue-Jun,Jin Qing-Hao,Kwak Kyung Chell,Chai Kyu-yun,Quan Zhe-Shan The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.1
The hepatoprotective effects of chalcone derivatives were evaluated in D-galactosamine/lipopolysaccharide (D-GaIN/LPS)-induced fulminant hepatic failure in mouse. Thirteen chalcone derivatives were synthesized for study and their hepatoprotective effects were evaluated by assessing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in serum. Chalcone preparations were injected into mice at 12 hand 1 h before intraperitoneal injection of D-GaIN/LPS. After abdominal administration, changes in AST and ALT between the control and treated groups were observed. Ten of the synthesized chalcone derivatives exhibited inhibitory effects on D-GaIN/LPS-induced levels of AST and ALT in mice. Compounds 2, 3, 8, 9, and 12 markedly reduced serum AST and ALT at 8 h, inhibited hepatocyte necrosis and showed significant hepatoprotective activities. The activity of compound 3 was compared with the bifendate (DDB) through oral administration. Compound 3 showed much higher inhibitory effects than bifendate for decreasing AST and ALT activity. The results indicate that compound 3 has strong hepatoprotective activity through suppression of tumor necrosis factoralpha (TNF-alpha) preduction, reduction of the histological change in the liver, and attenuated of hepatocyte apoptosis confirmed by DNA fragmentation assay.
Li-Min Tian,Ji-Ping Hao 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.5
There is a great difference in mechanical behavior between design model one-time loading and step-by-step construction process. This paper presents practical computational methods for simulating the structural behavior of long-span rigid steel structures during construction processes. It introduces the positioning principle of node rectification for installation which is especially suitable for rigid long-span steel structures. Novel improved nonlinear analytical methods, known as element birth and death of node rectification, are introduced based on several calculating methods, as well as a forward iteration of node rectification method. These methods proposed in this paper can solve the problem of element's 'floating' and can be easily incorporated in commercial finite element software. These proposed methods were eventually implemented in the computer simulation and analysis of the main stadium for the Universiade Sports Center during the construction process. The optimum construction scheme of the structure is determined by the improved algorithm and the computational results matched well with the measured values in the project, thus indicating that the novel nonlinear time-varying analysis approach is effective construction simulation of complex rigid long-span steel structures and provides useful reference for future design and construction.
Flexural behavior of reinforced lightweight concrete beams under reversed cyclic loading
Li-Kai Chien,Yi-Hao Kuo,Chung-Ho Huang,How-Ji Chen,Ping-Hu Cheng 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.3
This paper presents the results of an experimental investigation on the flexural behavior of doubly reinforced lightweight concrete (R.L.C.) beams tested under cyclic loading. A total of 20 beam specimens were tested. Test results are presented in terms of ductility index, the degradation of strength and stiffness, and energy dissipation. The flexural properties of R.L.C. beam were compared to those of normal concrete (R.C.) beams. Test results show that R.L.C. beam with low and medium concrete strength (20, 40MPa) performed displacement ductility similar to the R.C. beam. The ductility can be improved by enhancing the concrete strength or decreasing the tension reinforcement ratio. Using lightweight aggregate in concrete is advantageous to the dynamic stiffness of R.L.C. beam. Enhancement of concrete strength and increase of reinforcement ratio will lead to increase of the stiffness degradation of beam. The energy dissipation of R.L.C beam, similar to R.C. beam, increase with the increase of tension reinforcement ratio. The energy dissipation of unit load cycle for smaller tension reinforcement ratio is relatively less than that of beam with higher reinforcement ratio.
Down-regulation of miRNA-452 is Associated with Adriamycin-resistance in Breast Cancer Cells
Hu, Qing,Gong, Jian-Ping,Li, Jian,Zhong, Shan-Liang,Chen, Wei-Xian,Zhang, Jun-Ying,Ma, Teng-Fei,Ji, Hao,Lv, Meng-Meng,Zhao, Jian-Hua,Tang, Jin-Hai Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13
Adriamycin (ADR) is an important chemotherapeutic agent frequently used in treatment of breast cancer. However, resistance to ADR results in treatment failure in many patients. Recent studies have indicated that microRNAs (miRNAs) may play an important role in such drug-resistance. In the present study, microRNA-452 (miR-452) was found to be significantly down-regulated in adriamycin-resistant MCF-7 cells (MCF-7/ADR) compared with the parental MCF-7 cells by miRNA microarray and real-time quantitative PCR (RT-qPCR). MiR-452 mimics and inhibitors partially changed the adriamycin-resistance of breast cancer cells, as also confirmed by apoptosis assay. In exploring the potential mechanisms of miR-452 in the adriamycin-resistance of breast cancer cells, bioinformatics analysis, RT-qPCR and Western blotting showed that dysregulation of miR-452 played an important role in the acquired adriamycin-resistance of breast cancer, maybe at least in part via targeting insulin-like growth factor-1 receptor (IGF-1R).
Shear behavior of reinforced HPC beams made of a low cement content without shear reinforcements
Chao-Wei Tang,Yu-Ping Chen,How-Ji Chen,Chung-Ho Huang,Tsang-Hao Liu 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.1
High-performance concrete (HPC) usually has higher paste and lower coarse aggregate volumes than normal concrete. The lower aggregate content of HPC can affect the shear capacity of concrete members due to the formation of smooth fractured surfaces and the subsequent development of weak interface shear transfer. Therefore, an experimental investigation was conducted to study the shear strength and cracking behavior of full-scale reinforced beams made with low-cement-content high-performance concrete (LcHPC) as well as conventional HPC. A total of fourteen flexural reinforced concrete (RC) beams without shear reinforcements were tested under a two-point load until shear failure occurred. The primary design variables included the cement content, the shear span to effective depth ratio (a/d), and the tensile steel ratio (ρw). The results indicate that LcHPC beams show comparable behaviors in crack and ultimate shear strength as compared with conventional HPC beams. Overall, the shear strength of LcHPC beams was found to be larger than that of corresponding HPC beams, particularly for an a/d value of 1.5. In addition, the crack and ultimate shear strength increased as a/d decreased or ρw increased for both LcHPC beams and HPC beams. This investigation established that LcHPC is recommendable for structural concrete applications.
Dynamic analysis method for the progressive collapse of long-span spatial grid structures
Li-Min Tian,Jian-peng Wei,Ji-Ping Hao,Xian-tie Wang 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.23 No.4
In the past, the progressive collapse resulting from local failures during accidents has caused many tragedies and loss of life. Although long-span spatial grid structures are characterised by a high degree of static indeterminacy, the sudden failure of key members may lead to a catastrophic progressive collapse. For this reason, it is especially necessary to research the progressive collapse resistance capacity of long-span spatial grid structures. This paper presents an evaluation method of important members and a novel dynamic analysis method for simulating the progressive collapse of long-span spatial grid structures. Engineering cases were analysed to validate these proposed method. These proposed methods were eventually implemented in the progressive collapse analysis of the main stadium for the Universiade Sports Center. The roof of the structure was concluded to have good resistance against progressive collapse. The novel methods provide results close to practice and are especially suitable for the progressive collapse analysis of long-span spatial grid structures.
Parameter Analysis of Progressive Collapse Simulation of Long-Span Spatial Grid Structures
Jian-peng Wei,Li-Min Tian,Ji-Ping Hao 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.6
To accurately simulate the collapse process of long-span spatial grid structures, certain key parameters should be treated carefully. In the present study, the eff ects of the strain rate and the damage and fracture parameters were analyzed. A numerical simulation shows the following information: (1) First, the Cowper-Symonds model is utilized to simulate the rate-dependent material properties, illustrating that the strain rate eff ect can be overlooked for a progressive collapse simulation. (2) Then, the constant failure strain method is used for a damage and fracture simulation. The fi rst fracture of the members is postponed, and the fi nal failure patterns are therefore quite diff erent with an increase in the initial damage-equivalent plastic strain. (3) And, the progressive collapse pattern is unaff ected while the fracture is delayed or prevented with a greater equivalent plastic strain of the fi nal failure. These results can provide a reference for determining the damage and fracture parameters. (4) Finally, the equivalent plastic strain of the initial damage is relevant to the stress triaxiality. After considering the stress triaxiality, there is a signifi cant diff erence compared with the constant failure strain model. The stress triaxiality must therefore be considered.