Microstructure Formation Mechanism and Properties of AZ61 Alloy Processed by Melt Treatment with Vibrating Cooling Slope and Semisolid Rolling

Zhan Yong Zhao,Ren Guo Guan,Xiang Wang,Yang Li,Lei Dong,이종수,Chun Ming Liu 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5

A melt treatment with a vibrating cooling slope and a semisolid rolling process to produce an AZ61 alloy strip was proposed. The microstructure formation mechanism and the properties of the AZ61 alloy produced by the proposed process were investigated. Due to the high cooling rate and stirring action caused by the vibration cooling slope, the nucleation rate was greatly improved, which caused the formation of fine spherical or rosette primary grains. During the rolling process, the solid fraction increased from the entrance to the exit of the roll gap, and under the shearing action of the roller, the distribution of solute in the melt was homogenous, and the primary grains grew further. When the casting temperature was 680 °C,a strip with a cross section of 4 mm×160 mm was produced and a homogeneous microstructure was obtained. The ultimate tensile strength of the AZ61 alloy strip produced by the proposed method reached 242 MPa, and the corresponding elongation to failure was 4%, which were better than those achieved in previous similar studies.

Methylenetetrahydrofolate Reductase Polymorphisms and Susceptibility to Esophageal Cancer in Chinese Populations: a Meta-analysis

Yang, Yong-Bin,Shang, Yan-Hong,Tan, Yan-Li,Kang, Xian-Jiang,Meng, Ming,Zhao, Zhan-Xue Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Although many epidemiologic studies investigated the methylenetetrahydrofolate reductase (MTHFR) polymorphisms and their associations with esophageal cancer, definite conclusions could not be drawn. To clarify the effects of MTHFR polymorphisms on the risk of esophageal cancer, a meta-analysis was here performed in Chinese populations. A total of 16 studies including 3,040 cases and 4,127 controls were involved in this metaanalysis. Overall, significant associations were found between the MTHFR C677T polymorphism and esophageal cancer risk when all studies in Chinese populations were pooled into the meta-analysis (T vs. C, OR = 1.19, 95% CI = 1.06-1.34; TT vs. CC, OR = 1.35, 95% CI = 1.07-1.70; TT+ CT vs. CC, OR = 1.29, 95% CI = 1.08-1.54; TT vs. CC + CT, OR = 1.19, 95% CI = 1.03-1.37). In subgroup analyses stratified by ethnicity and source of controls, the same results were found in Kazakh (TT vs. CC, OR = 1.38, 95% CI = 1.02-1.87; TT + CT vs. CC, OR = 1.50, 95% CI = 1.03-2.18), in not stated populations (T vs. C, OR = 1.24, 95% CI = 1.08-1.42; TT vs. CC, OR = 1.47, 95% CI = 1.10-1.96; TT + CT vs. CC, OR = 1.30, 95% CI = 1.05-1.60; TT vs. CC + CT, OR = 1.32, 95% CI = 1.12-1.56), and in hospital-based studies (T vs. C, OR = 1.34, 95% CI = 1.19-1.51; TT vs. CC, OR = 1.81, 95% CI = 1.37-2.39; TT + CT vs. CC, OR = 1.51, 95% CI = 1.26-1.83; and TT vs. CC + CT, OR = 1.39, 95% CI = 1.13-1.70). In conclusion, this meta-analysis provides evidence that the MTHFR C677T polymorphism contributes to esophageal cancer development in Chinese populations.

Immune and Anti-oxidant Functions of Ethanol Extracts of Scutellaria baicalensis Georgi in Mice Bearing U14 Cervical Cancers

Peng, Yong,Guo, Cong-Shan,Li, Pan-Xia,Fu, Zhan-Zhao,Gao, Li-Ming,Di, Ya,Ju, Ya-Kun,Tian, Ru,Xue, Jia-Jia Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.10

Background: The objective was to study the effect of Scutellaria baicalensis Georgi ethanol extracts (SBGE) on immune and anti-oxidant function in U14 tumor-bearing mice. Materials and Methods: U14 tumor-bearing mice were randomly divided into eight groups: a control group, a cyclophosphamide (CTX) group, three dose groups of SBGEI (high, medium, low), and three dose groups of SBGEII (high, medium, low). After two weeks, the thymus and spleen weight indices of mice bearing U14 cervical cancer were calculated. Enzyme linked immunosorbent assays (ELISA) was used to determine the levels of serum IL-2, TNF-${\alpha}$, IL-8, and PCNA. MDA activity and SOD activity in plasma were measured with detection kits. Results: In the SBGE groups, thymus weight and spleen weight indices of U14 tumor-bearing mice were significantly higher than in the control group or CTX group (p<0.05). Compared to control group, the levels of serum IL-2 and TNF-${\alpha}$ in U14 tumor-bearing mice increased significantly, whereas the contents of serum IL-8 and PCNA decreased (p<0.05). The activity of SOD increased with the growing dose of SBGE, while the activity of MDA decreased significantly in the highe-rdose groups of SBGE. Conclusions: These findings suggested that SBGE, especially at high dose, 1000 mg/kg, showed significant immune and anti-oxidant effects infU14 tumor-bearing mice, which might be the mechanisms of SBGE inhibition of tumor growth.

Boundary Layer and Cooling Rate and Microstructure Formation on the Cooling Sloping Plate

Ren Guo Guan,Zhan Yong Zhao,Run Ze Chao,Lei Dong,이종수,Chun Ming Liu 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5

During melt treatment by cooling sloping plate, laminar flow and turbulent flow exist on sloping plate surface commonly. The thickness of velocity boundary layer and the critical transfer distance from laminar flow to turbulent flow increase with the decrease of initial flow velocity. The thickness of temperature boundary layer increases with the increment of flow distance and the decrease of initial flow velocity. The melt cooling rate and melt thickness have an inverse proportion relationship. The melt cooling rate of cooling sloping plate process can reach 102-103 K/s and belongs to meta-rapid solidification scope. Uniform solute field and high cooling rate can lead to eruptive nucleation. In addition, a large quantity of heterogonous nuclei appears on the sloping plate surface, and vibrating flow can enable heterogonous nucleus to escape off the plate, which leads to nucleus multiplication. Under relative uniform solute field and high cooling rate, some grains can keep stable growth surface, go on growing with the round surface and finally maintain their globular structure. However, there are always some grains that grow along a certain preferred direction, but under vibrating flow their dendritic arms break and transform into near spherical structure.

Microstructure Formation Mechanism and Properties of a Mg-3Sn-1Mn (wt%) Magnesium Alloy Processed by a Novel Semisolid Continuous Shearing and Rolling Process

Ren Guo Guan,Zhan Yong Zhao,Chao Lian,Tong Cui,이종수 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.1

A novel semisolid Continuous Shearing and Rolling (CSR) process for producing a Mg-3Sn-1Mn (wt%)alloy strip is developed, and the microstructure formation mechanism and properties of the Mg-3Sn-1Mn (wt%) alloy processed by this process are investigated. At a casting temperature of 690°C and a roll speed of 0.052 m·s.1, a Mg-3Sn-1Mn (wt%) alloy strip with a cross section size of 4×160 mm was produced by the proposed process. Under strong cooling and shearing actions, eruptive nucleation, direct globular grain growth and dendrite arm breakage took place during the process, which caused formations of fine spherical grains. The grain size and roundness of the Mg-3Sn-1Mn (wt%) alloy strip increased with increasing increments of the casting temperature. In this perspective, roll speed obviously affects grain shape. The ultimate tensile strength and elongation of the Mg-3Sn-1Mn (wt%) alloy strip reached 205.93 MPa and 7.2%.

Immunosuppressive Effects of New Cyclolanostane Triterpene Diglycosides from the Aerial Part of Cimicifuga foetida

Rui-Le Pan,Di-Hua Chen,Jian-Yong Si,Xiao-Hong Zhao,Zhan Li,Li Cao 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.2

Two new cyclolanostane diglycosides, cimifoetiside A (1) and cimifoetiside B (2), were isolated from an 80% ethanolic extract of the aerial part of Cimicifuga foetida L. (Ranuculaceae). Using spectral data and chemical analysis, the structures of 1 and 2 were identified as (23R, 24S) cimicigenol 3-O-β-D-glucopyranosyl-(1"→3')-β-D-xylopyranoside and (23R, 24S) cimicigenol 3-O-β-D-glucopyranosyl-(1"→2')-β-D-xylopyranoside, respectively. The in vitro immunosuppressive effects of the two new compounds 1 and 2, as well as four other known cyclolanostane saponins 3-6 on T cells were evaluated. All the agents tested effectively inhibited the proliferation of murine splenocytes induced by Concanavalin A (ConA), with IC50 values ranging from 12.7 nM to 33.3 nM.

Density measurement and equal density temperature of CO2+brine from Dagang - formation from 313 to 363 K

Yi Zhang,Weiwei Jian,Yangchun Zhan,Yongchen Song,Mingjun Yang,Jiafei Zhao,Yu Liu,Weiguo Liu,Yong Shen 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

Densities of CO2+Dagang - formation brine solution were measured by a magnetic suspension balance(MSB) in the pressure range from (10 to 18) MPa, at the temperatures from (313.15 to 363.15) K and CO2 mass frac-tions at 0, 0.0101, 0.0198 and 0.0299. The experimental results revealed that the solution densities increased linearlywith the increasing pressure and CO2 concentration, while decreasing with the increasing temperatures in the experi-mental range. When the temperature increased from (313.15 to 363.15) K, the slopes of the densities versus (vs.) CO2mass fractions decreased from (0.193 to 0.106) g·cm−3. A correlation equation was developed based on thermody-namic theory and experimental data. The absolute average deviation between the correlation equation and the experi-mental data was 0.05%, and the maximum deviation was 0.37% for the density of CO2+water/brine solution in com-mon geological storage conditions. According to the density of CO2 - free brine and apparent molar volume of CO2 inbrine, the equal density temperature (Te) of CO2+Dagang brine solution was obtained at 464.67 K when pressure is10MPa, which means that the density of brine dissolved with CO2 will be less than that of CO2-free brine when thetemperature is higher than 464.67 K at 10MPa. In this work the formation temperature of the Dagang oilfield reser-voir is from 313.15 K to 363.15 K, which is lower than the equal density temperature. Therefore, the safety of CO2 stor-age in Dagang oilfield reservoir can be guaranteed.

Two new benzylisoquinoline alkaloids from Thalictrum foliolosum and their antioxidant and in vitro antiproliferative properties

Da-Hong Li,Jia Guo,Wen Bin,Nan Zhao,Kai-bo Wang,Jian-yong Li,Zhan-Lin Li,Hui-Ming Hua 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.7

Two novel rare chloro-containing benzylisoquinolinealkaloids, thalfoliolosumines A (1) and B (2),along with eight known isoquinoline alkaloids (3–10) wereisolated from the whole plant of Thalictrum foliolosum. The structures of these compounds were elucidated byspectral analyses, including 1D and 2D NMR (COSY,HSQC, HMBC and NOESY) experiments. The antiproliferativeeffects of all the isolated compounds were evaluatedby MTT method against MCF-7, PC-3, and U937cells, and trypan blue method against HL-60 cells. Newcompounds 1 and 2 exhibited moderate in vitro antiproliferativeactivity against MCF-7, PC-3, and HL-60 cells,and good inhibitory effects against U937 cells with IC50values of 7.50 and 6.97 μM, respectively. Compounds 7and 10 showed the strongest in vitro antiproliferative withIC50 values of 0.93 and 1.69 lM against HL-60 cell line. The antioxidant properties were also measured, bisbenzyltetrahydroisoquinolinealkaloids 3–6 showed the strongestantioxidant activities in ABTS assay.