Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an exce...Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an excellent NLO cryst al for UV region,while the high temperature one (α BBO) is known as a good bir efringent material.α BBO crystal possesses better transparency in the ultravio let region compared with commonly used YVO 4 and CaCO 3 crystals.However,due t o phase transition problem,it is difficult to grow single α BBO crystals by D CZ method,which restricts its wider application.α BBO crystal usually cracks upon cooling resulted from phase transition to β phase.Therefore,it is difficult to grow β BBO single crystals directly from pure BaB 2O 4 mel t;however,to grow single crystals of α BBO is not easy,either. Our recent experiments showed that one could avoid cracking of α BBO cryst als by Sr 2+ doping.This minute amount of Sr 2+ plays the role of structure stabilizer,which inhibits structural reconstruction. In this way,Sr 2+ d op ed BBO single crystals do not subject to phase transition from 925℃ down to roo m temperature. We have mow successfully grown out α BBO single crystals 30mm in diameter by D CZ method from Sr x Ba 1- x BO 4 melt with Sr concentration 0.3 0 .5%.The ratation rate is 10 15r/min,pulling speed is 1 2mm/h.Preliminary tests revealed that its structure and physic chemical properties were almost identic al to those grown from pure melts.These Sr 2+ doped α BBO crystals are no w being widely used in optical isolators.展开更多
目的探讨多被银莲花总皂甙对人涎腺腺样囊性癌高肺转移细胞(ACC-M)内Bcl-2和Bax蛋白表达的影响。方法将体外培养的ACC-M细胞随机分为实验组与对照组,分别加入50μg/m L多被银莲花总皂甙溶液2 m L、含同样浓度二甲基亚砜的RPMI1640培养液...目的探讨多被银莲花总皂甙对人涎腺腺样囊性癌高肺转移细胞(ACC-M)内Bcl-2和Bax蛋白表达的影响。方法将体外培养的ACC-M细胞随机分为实验组与对照组,分别加入50μg/m L多被银莲花总皂甙溶液2 m L、含同样浓度二甲基亚砜的RPMI1640培养液2 m L。分别于培养24、48、72 h用Western blotting法检测细胞内Bcl-2和Bax蛋白的表达量。结果对照组各时间点Bcl-2、Bax蛋白相对表达量及Bax/Bcl-2比较差异均无统计学意义(P均>0.05);实验组各时间点Bcl-2、Bax蛋白相对表达量及Bax/Bcl-2比较差异均有统计学意义(P均<0.05);两组间各时间点Bcl-2、Bax蛋白相对表达量及Bax/Bcl-2比较差异均有统计学意义(P均<0.05)。结论多被银莲花总皂甙可上调ACC-M细胞内Bax蛋白表达,同时下调Bcl-2蛋白表达,导致Bax/Bcl-2升高。展开更多
文摘Barium metaborate (BaB 2O 4) exists in two forms the high temperature for m α phase and the low temperature form β phase,with the phase transition poi nt at around 925℃.The low temperature phase (β BBO) is an excellent NLO cryst al for UV region,while the high temperature one (α BBO) is known as a good bir efringent material.α BBO crystal possesses better transparency in the ultravio let region compared with commonly used YVO 4 and CaCO 3 crystals.However,due t o phase transition problem,it is difficult to grow single α BBO crystals by D CZ method,which restricts its wider application.α BBO crystal usually cracks upon cooling resulted from phase transition to β phase.Therefore,it is difficult to grow β BBO single crystals directly from pure BaB 2O 4 mel t;however,to grow single crystals of α BBO is not easy,either. Our recent experiments showed that one could avoid cracking of α BBO cryst als by Sr 2+ doping.This minute amount of Sr 2+ plays the role of structure stabilizer,which inhibits structural reconstruction. In this way,Sr 2+ d op ed BBO single crystals do not subject to phase transition from 925℃ down to roo m temperature. We have mow successfully grown out α BBO single crystals 30mm in diameter by D CZ method from Sr x Ba 1- x BO 4 melt with Sr concentration 0.3 0 .5%.The ratation rate is 10 15r/min,pulling speed is 1 2mm/h.Preliminary tests revealed that its structure and physic chemical properties were almost identic al to those grown from pure melts.These Sr 2+ doped α BBO crystals are no w being widely used in optical isolators.
文摘目的探讨多被银莲花总皂甙对人涎腺腺样囊性癌高肺转移细胞(ACC-M)内Bcl-2和Bax蛋白表达的影响。方法将体外培养的ACC-M细胞随机分为实验组与对照组,分别加入50μg/m L多被银莲花总皂甙溶液2 m L、含同样浓度二甲基亚砜的RPMI1640培养液2 m L。分别于培养24、48、72 h用Western blotting法检测细胞内Bcl-2和Bax蛋白的表达量。结果对照组各时间点Bcl-2、Bax蛋白相对表达量及Bax/Bcl-2比较差异均无统计学意义(P均>0.05);实验组各时间点Bcl-2、Bax蛋白相对表达量及Bax/Bcl-2比较差异均有统计学意义(P均<0.05);两组间各时间点Bcl-2、Bax蛋白相对表达量及Bax/Bcl-2比较差异均有统计学意义(P均<0.05)。结论多被银莲花总皂甙可上调ACC-M细胞内Bax蛋白表达,同时下调Bcl-2蛋白表达,导致Bax/Bcl-2升高。
