Two experiments were carried out on the same compact strip production (CSP) line, which differs in that one of them experienced γ→α→γ thermal history. The differences in microstructure, precipitation, misorientat...Two experiments were carried out on the same compact strip production (CSP) line, which differs in that one of them experienced γ→α→γ thermal history. The differences in microstructure, precipitation, misorientation etc between two experiments were investigated by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron back-scattered diffraction (EBSD) and positron annihilation technique (PAT). The carbon concentration in matrix is more inhomogeneous in the experiment than that with γ→α→γ7 thermal history. The specific precipitation characteristic in the experiment without γ→α→γ thermal history is discussed on the basis of different carbon diffusion behavior and interaction between dislocation and excess carbon.展开更多
Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-t...Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-thin hot strip of low carbon steel produced by CSP(Compact Strip Production) technique was investigated. The value of each strengthening mechanism andits contribution percentage to yield strength were achieved. The results show that refinementstrengthening is the predominant strengthening mode; precipitation strengthening and dislocationstrengthening are second to it, their contributions to yield strength are almost equal.展开更多
AIM: To study the effect of ginsenoside Rgl and Rhl on the anti - tumor activity of dendritic cells (DC). METHODS: Effect of Rgl and Rhl on the production of IL- 12 p40 protein was detected by ELISA, and the IL- 12 p4...AIM: To study the effect of ginsenoside Rgl and Rhl on the anti - tumor activity of dendritic cells (DC). METHODS: Effect of Rgl and Rhl on the production of IL- 12 p40 protein was detected by ELISA, and the IL- 12 p40 mRNA level of DC was monitored by RT- PCR. Anti - tumor activity of DC- LPAK was detemnined by neutral red staining assay. RESULTS: The results of ELLSA showed that Rgl and Rhl significantly enhanced the production of IL- 12 p40 of DC. Rgl at 1 mg/L and Rhl at 100 mg/L upregulated the IL- 12 p40 mRNA level. Rgl and Rhl enhanced the anti - tumor ability of DC, induced lyrnphokine and PHA activated killer (DC-LPAK) on human papillate tumor cell line. Each dose of Rgl can obviously accelerate the eytotoxity to L929 at the E: T ratio of 5 : 1 (P<0.05,0.01 ), while only Rhl 10 mg/L enhanced the eytotoxity ability of DC- LPAK (P < 0.05). CONCLUSION: Rgl and Rhl enhanced the production of IL-12 p40. This effect may be mediated by the increase in the mRNA level. As a result, Rg1 and Rhl oromote the ability of DC to stimulate the cytotoxitie aetieity of DC - LPAK.展开更多
The microstructures of low carbon steel before, during and after rollingdeformation of each stand were observed using optical microscope. The result showed that themicrostructures were very fine after six passes rolli...The microstructures of low carbon steel before, during and after rollingdeformation of each stand were observed using optical microscope. The result showed that themicrostructures were very fine after six passes rolling deformation. The effect of the first standreduction on microstructure refinement was very distinct. During the rolling process, with theincrease of the accumulated strain, the microstructures would further refine, and the density ofdislocation would increase at the same time. In continuous casting thin slabs and each finishingstand, lots of observed precipitates were mainly A1_2O_3 and MnS along the grain boundaries or ingrains, which played an important role in the mechanical properties of the hot strips of low carbonsteel produced by CSP (compact strip production) technology.展开更多
The microstructure and precipitation mechanism of ultra-thin hotstrip produced by CSP technology were analyzed by electron backscattered diffraction(EBSD), H-800 transmission electronmicroscope(TEM)and thermodynamics ...The microstructure and precipitation mechanism of ultra-thin hotstrip produced by CSP technology were analyzed by electron backscattered diffraction(EBSD), H-800 transmission electronmicroscope(TEM)and thermodynamics theory. The EBSD results show thatthe finishing hot rolling microstructures are mixture ofrecrystallized and deformed austenite. After phase transformation,ferrite gra- ins embody substructures and dislocations that ledultra-thin hot strip high strength and relatively low elongationrate. TEM observations show that there are a lot of fine anddispersive precipitates in microstructure.展开更多
Spike protein is one of the major structural proteins of severe acute respiratory syndrome-coronavirus. It is essential for the interaction of the virons with host cell receptors and subsequent fusion of the viral env...Spike protein is one of the major structural proteins of severe acute respiratory syndrome-coronavirus. It is essential for the interaction of the virons with host cell receptors and subsequent fusion of the viral envelop with host cell membrane to allow infection. Some spike proteins of coronavirus, such as MHV, HCoV-OC43, AIBV and BcoV, are proteolytically cleaved into two subunits, S 1 and S2. In contrast, TGV, FIPV and HCoV-229E are not. Many studies have shown that the cleavage of spike protein seriously affects its function. In order to investigate the maturation and proteolytic processing of the S protein of SARS CoV, we generated S 1 and S2 subunit specific antibodies (Abs) as well as N, E and 3CL protein-specific Abs. Our results showed that the antibodies could efficiently and specifically bind to their corresponding proteins from E.coli expressed or lysate of SARS-CoV infected Vero-E6 cells by Western blot analysis. Furthermore, the anti-S 1 and S2 Abs were proved to be capable of binding to SARS CoV under electron microscope observation. When S2 Ab was used to perform immune precipitation with lysate of SARS-CoV infected cells, a cleaved S2 fragment was detected with S2-specific mAb by Western blot analysis. The data demonstrated that the cleavage of S protein was observed in the lysate, indicating that proteolytic processing of S protein is present in host cells.展开更多
基金Authors acknowledge the financial support from the National Natural Science Foundation of China(No.50334010).
文摘Two experiments were carried out on the same compact strip production (CSP) line, which differs in that one of them experienced γ→α→γ thermal history. The differences in microstructure, precipitation, misorientation etc between two experiments were investigated by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron back-scattered diffraction (EBSD) and positron annihilation technique (PAT). The carbon concentration in matrix is more inhomogeneous in the experiment than that with γ→α→γ7 thermal history. The specific precipitation characteristic in the experiment without γ→α→γ thermal history is discussed on the basis of different carbon diffusion behavior and interaction between dislocation and excess carbon.
基金This work was financially supported by the state foundation for key projects: Fundamental Research on New Generation of Steels (No: G1998061500).
文摘Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-thin hot strip of low carbon steel produced by CSP(Compact Strip Production) technique was investigated. The value of each strengthening mechanism andits contribution percentage to yield strength were achieved. The results show that refinementstrengthening is the predominant strengthening mode; precipitation strengthening and dislocationstrengthening are second to it, their contributions to yield strength are almost equal.
文摘AIM: To study the effect of ginsenoside Rgl and Rhl on the anti - tumor activity of dendritic cells (DC). METHODS: Effect of Rgl and Rhl on the production of IL- 12 p40 protein was detected by ELISA, and the IL- 12 p40 mRNA level of DC was monitored by RT- PCR. Anti - tumor activity of DC- LPAK was detemnined by neutral red staining assay. RESULTS: The results of ELLSA showed that Rgl and Rhl significantly enhanced the production of IL- 12 p40 of DC. Rgl at 1 mg/L and Rhl at 100 mg/L upregulated the IL- 12 p40 mRNA level. Rgl and Rhl enhanced the anti - tumor ability of DC, induced lyrnphokine and PHA activated killer (DC-LPAK) on human papillate tumor cell line. Each dose of Rgl can obviously accelerate the eytotoxity to L929 at the E: T ratio of 5 : 1 (P<0.05,0.01 ), while only Rhl 10 mg/L enhanced the eytotoxity ability of DC- LPAK (P < 0.05). CONCLUSION: Rgl and Rhl enhanced the production of IL-12 p40. This effect may be mediated by the increase in the mRNA level. As a result, Rg1 and Rhl oromote the ability of DC to stimulate the cytotoxitie aetieity of DC - LPAK.
基金This work was financially supported by the "973" Key Foundation of China (No. GJ998061500)
文摘The microstructures of low carbon steel before, during and after rollingdeformation of each stand were observed using optical microscope. The result showed that themicrostructures were very fine after six passes rolling deformation. The effect of the first standreduction on microstructure refinement was very distinct. During the rolling process, with theincrease of the accumulated strain, the microstructures would further refine, and the density ofdislocation would increase at the same time. In continuous casting thin slabs and each finishingstand, lots of observed precipitates were mainly A1_2O_3 and MnS along the grain boundaries or ingrains, which played an important role in the mechanical properties of the hot strips of low carbonsteel produced by CSP (compact strip production) technology.
基金[This work is financially supported by the state foundation for key projects: Fundamental Research on New Generation of Steels (No: G1998061500).]
文摘The microstructure and precipitation mechanism of ultra-thin hotstrip produced by CSP technology were analyzed by electron backscattered diffraction(EBSD), H-800 transmission electronmicroscope(TEM)and thermodynamics theory. The EBSD results show thatthe finishing hot rolling microstructures are mixture ofrecrystallized and deformed austenite. After phase transformation,ferrite gra- ins embody substructures and dislocations that ledultra-thin hot strip high strength and relatively low elongationrate. TEM observations show that there are a lot of fine anddispersive precipitates in microstructure.
文摘Spike protein is one of the major structural proteins of severe acute respiratory syndrome-coronavirus. It is essential for the interaction of the virons with host cell receptors and subsequent fusion of the viral envelop with host cell membrane to allow infection. Some spike proteins of coronavirus, such as MHV, HCoV-OC43, AIBV and BcoV, are proteolytically cleaved into two subunits, S 1 and S2. In contrast, TGV, FIPV and HCoV-229E are not. Many studies have shown that the cleavage of spike protein seriously affects its function. In order to investigate the maturation and proteolytic processing of the S protein of SARS CoV, we generated S 1 and S2 subunit specific antibodies (Abs) as well as N, E and 3CL protein-specific Abs. Our results showed that the antibodies could efficiently and specifically bind to their corresponding proteins from E.coli expressed or lysate of SARS-CoV infected Vero-E6 cells by Western blot analysis. Furthermore, the anti-S 1 and S2 Abs were proved to be capable of binding to SARS CoV under electron microscope observation. When S2 Ab was used to perform immune precipitation with lysate of SARS-CoV infected cells, a cleaved S2 fragment was detected with S2-specific mAb by Western blot analysis. The data demonstrated that the cleavage of S protein was observed in the lysate, indicating that proteolytic processing of S protein is present in host cells.
