High entropy boride ceramics have great potential as structural materials serving in extreme environ-ments.However,their applications are limited by the difficulty of sintering.In the present study,dense(Ti_(0.2)Zr_(0...High entropy boride ceramics have great potential as structural materials serving in extreme environ-ments.However,their applications are limited by the difficulty of sintering.In the present study,dense(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)ceramics with B_(4)C additions were prepared through pressureless sintering at as low as 1900℃.Calculations based on the CALPHAD approach predict that(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)starts to melt at about 3315℃whilst B_(4)C additions reduce the temperature and broaden the tempera-ture region where solid and liquid coexist.Results showed that the introduction of B_(4)C could trigger the densification of(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)at a lower temperature and promote their densification signif-icantly.The relative density of samples with 5 wt%of B_(4)C additions sintered at 1900 and 2000℃was 97.7%and 99.7%,respectively.While the sintering temperature was further increased to 2100℃,the liquid phase was reactively formed,leading to the rapid grain coarsening in samples with B_(4)C additions.Strengthened by well-dispersed B_(4)C grains,the sample with 5 wt%B_(4)C sintered at 2000℃exhibited excellent mechanical properties with the Vickers hardness,flexural strength,and fracture toughness of 21.07±2.09 GPa,547±45 MPa,and 5.24±0.14 MPa m^(1/2),which are comparable or even higher than counterparts sintered under pressure.展开更多
In vitro cultured human neuroblastoma SH-SY5Y cells were pretreated with 50 or 5 ug/mL geniposide for 12 hours and exposed to 400 umol/L corticosterone. Corticosterone exposure in cultures not pretreated with geniposi...In vitro cultured human neuroblastoma SH-SY5Y cells were pretreated with 50 or 5 ug/mL geniposide for 12 hours and exposed to 400 umol/L corticosterone. Corticosterone exposure in cultures not pretreated with geniposide resulted in inhibited cell growth, reduced cell survival, and increased P53 and P21 protein expression. However, in geniposide pretreated SH-SY5Y cells, cell viability and the number of cells in the G2 phase of the cell cycle were significantly increased, P21 and P53 protein expression was reduced, and cell apoptosis was inhibited following corticosterone exposure. These results indicate that geniposide can protect SH-SY5Y cells against high-dose corticosterone-induced injury.展开更多
The Chinese herb Shuyusan, whose main constituent is jasminoidin, has been shown to protect SH-SY5Y cells against corticosterone-induced damage. SH-SY5Y cells injured by 400 μmol/L cor- ticosterone were treated with ...The Chinese herb Shuyusan, whose main constituent is jasminoidin, has been shown to protect SH-SY5Y cells against corticosterone-induced damage. SH-SY5Y cells injured by 400 μmol/L cor- ticosterone were treated with 5 and 30 μg/mL Shuyusan-containing serum. Results revealed that Shuyusan-containing serum elevated the survival rate of SH-SY5Y cells, reduced Bax expression, increased Bcl-2 expression, markedly elevated brain-derived neurotrophic factor mRNA expression, and blocked cell apoptosis. Moreover, the effect of high-dose （30 μg/mL） Shuyusan-containing se- rum was more remarkable. Therefore, Shuyusan-containing serum appears to protect SH-SY5Y cells against corticosterone-induced impairment by adjusting the expression of apoptosis-associ- ated proteins and brain-derived neurotrophic factor. Moreover, high-dose Shuyusan-containing se- rum has a protective effect on high-dose corticosterone-induced impairment.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52022072,52293373,52332003,52202067)the National Key R&D Programs(No.2021YFB3701400)+1 种基金the Hubei Provincial Natural Science Foundation of China(Distinguished Young Scholars 2022CFA042)the Independent Innovation Projects of Hubei Longzhong Laboratory(No.2022ZZ-10).
文摘High entropy boride ceramics have great potential as structural materials serving in extreme environ-ments.However,their applications are limited by the difficulty of sintering.In the present study,dense(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)ceramics with B_(4)C additions were prepared through pressureless sintering at as low as 1900℃.Calculations based on the CALPHAD approach predict that(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)starts to melt at about 3315℃whilst B_(4)C additions reduce the temperature and broaden the tempera-ture region where solid and liquid coexist.Results showed that the introduction of B_(4)C could trigger the densification of(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B_(2)at a lower temperature and promote their densification signif-icantly.The relative density of samples with 5 wt%of B_(4)C additions sintered at 1900 and 2000℃was 97.7%and 99.7%,respectively.While the sintering temperature was further increased to 2100℃,the liquid phase was reactively formed,leading to the rapid grain coarsening in samples with B_(4)C additions.Strengthened by well-dispersed B_(4)C grains,the sample with 5 wt%B_(4)C sintered at 2000℃exhibited excellent mechanical properties with the Vickers hardness,flexural strength,and fracture toughness of 21.07±2.09 GPa,547±45 MPa,and 5.24±0.14 MPa m^(1/2),which are comparable or even higher than counterparts sintered under pressure.
基金the Capital Specific Clinical Medical Subject of Beijing Science and Technology Commission,No.Z090507017709030
文摘In vitro cultured human neuroblastoma SH-SY5Y cells were pretreated with 50 or 5 ug/mL geniposide for 12 hours and exposed to 400 umol/L corticosterone. Corticosterone exposure in cultures not pretreated with geniposide resulted in inhibited cell growth, reduced cell survival, and increased P53 and P21 protein expression. However, in geniposide pretreated SH-SY5Y cells, cell viability and the number of cells in the G2 phase of the cell cycle were significantly increased, P21 and P53 protein expression was reduced, and cell apoptosis was inhibited following corticosterone exposure. These results indicate that geniposide can protect SH-SY5Y cells against high-dose corticosterone-induced injury.
基金funded by a grant from the Scientific Research Key Project of Armed Forces during the "12 th Five-Year Plan" Period,No.CWS12J129
文摘The Chinese herb Shuyusan, whose main constituent is jasminoidin, has been shown to protect SH-SY5Y cells against corticosterone-induced damage. SH-SY5Y cells injured by 400 μmol/L cor- ticosterone were treated with 5 and 30 μg/mL Shuyusan-containing serum. Results revealed that Shuyusan-containing serum elevated the survival rate of SH-SY5Y cells, reduced Bax expression, increased Bcl-2 expression, markedly elevated brain-derived neurotrophic factor mRNA expression, and blocked cell apoptosis. Moreover, the effect of high-dose （30 μg/mL） Shuyusan-containing se- rum was more remarkable. Therefore, Shuyusan-containing serum appears to protect SH-SY5Y cells against corticosterone-induced impairment by adjusting the expression of apoptosis-associ- ated proteins and brain-derived neurotrophic factor. Moreover, high-dose Shuyusan-containing se- rum has a protective effect on high-dose corticosterone-induced impairment.
