SiC-MgAl_(2)O_(4) composites with SiAlON polytypoids(12H and 21R)as the bonding phases were prepared using SiC fine powder,MgAl_(2)O_(4)fine powder and Al powder as raw materials.The effects of the firing temperature ...SiC-MgAl_(2)O_(4) composites with SiAlON polytypoids(12H and 21R)as the bonding phases were prepared using SiC fine powder,MgAl_(2)O_(4)fine powder and Al powder as raw materials.The effects of the firing temperature and the mass ratio of SiC to MgAl_(2)O_(4) on the formation of SiAlON polytypoids as well as on the properties of samples were studied.The formation mechanism of SiAlON polytypoids was discussed.The results show that firing at 1650℃in the nitrogen atmosphere,SiC-MgAl_(2)O_(4) composites with SiAlON polytypoids can be obtained.With the gradual increase of the mass ratio of SiC to MgAl_(2)O_(4) in the raw materials,12H forms first,and then coexists with 21H,finally,all 12H converts into 21R in samples.Both phases are plate crystals with flat and smooth edges.Compared with 21R,12H is conducive to improving the density and the cold mechanical properties of materials.After firing at 1650℃in the nitrogen atmosphere,with the mass ratio of SiC to MgAl_(2)O_(4) of 6:4,the sample has the cold modulus of rupture of 27 MPa,showing the optimal performance.展开更多
本文利用PCR技术扩增了6个野生群体大泷六线鱼线粒体12S r RNA基因的部分序列。在获得的582bp碱基序列中,共检测到314个变异位点,占总位点数的53.95%。34尾个体共定义了16种单倍型,6个群体的单倍型多样性指数为0.40~1.00,核苷酸多样性...本文利用PCR技术扩增了6个野生群体大泷六线鱼线粒体12S r RNA基因的部分序列。在获得的582bp碱基序列中,共检测到314个变异位点,占总位点数的53.95%。34尾个体共定义了16种单倍型,6个群体的单倍型多样性指数为0.40~1.00,核苷酸多样性指数为0.00071~0.10441。中性检验Fu's Fs值为1.19782(P<0.01)。分子变异分析表明:Fst=0.88326(P<0.01),群体间和群体内变异分别为88.33%和11.67%。不同个体间的遗传距离构建的NJ和MP系统树表明,东港和旅顺群体亲缘关系较近,构成一个分支,其他群体构成另一分支。展开更多
目的观察喘可治注射液(CKZ)对慢性阻塞性肺疾病(COPD)大鼠肺组织IL-12/IL-12R/STAT4信号通路的影响。方法 50只SD大鼠随机分为正常组,模型组,CKZ高、中、低剂量(CKZ-H、CHZ-M、CKZ-L)组。除正常组外,各组复制COPD大鼠模型,并给予相应药...目的观察喘可治注射液(CKZ)对慢性阻塞性肺疾病(COPD)大鼠肺组织IL-12/IL-12R/STAT4信号通路的影响。方法 50只SD大鼠随机分为正常组,模型组,CKZ高、中、低剂量(CKZ-H、CHZ-M、CKZ-L)组。除正常组外,各组复制COPD大鼠模型,并给予相应药物治疗,观察CKZ对COPD大鼠血清和肺泡灌洗液(BALF)中γ-干扰素(IFN-γ)、白细胞介素12(IL-12)、白细胞介素12受体(IL-12R)以及肺组织信号转导子和转录激活子4(STAT4)m RNA表达的影响。结果喘可治注射液各剂量组肺组织病理形态均有不同程度的改善,且降低COPD大鼠血清和BALF中IFN-γ、IL-12、IL-12R(除CKZ-L组BALF中IL-12R外)水平(P<0.05,P<0.01),可抑制大鼠肺组织STAT4 m RNA的表达(P<0.01,P<0.05)。结论喘可治注射液能一定程度改善COPD大鼠肺组织病理损害,其作用机制可能与其抑制IFN-γ、IL-12、IL-12R表达,干扰IL-12/IL-12R/STAT4信号通路对靶基因的激活,下调STAT4 m RNA表达,进而调节Th1/Th2分化失衡有关。展开更多
文摘SiC-MgAl_(2)O_(4) composites with SiAlON polytypoids(12H and 21R)as the bonding phases were prepared using SiC fine powder,MgAl_(2)O_(4)fine powder and Al powder as raw materials.The effects of the firing temperature and the mass ratio of SiC to MgAl_(2)O_(4) on the formation of SiAlON polytypoids as well as on the properties of samples were studied.The formation mechanism of SiAlON polytypoids was discussed.The results show that firing at 1650℃in the nitrogen atmosphere,SiC-MgAl_(2)O_(4) composites with SiAlON polytypoids can be obtained.With the gradual increase of the mass ratio of SiC to MgAl_(2)O_(4) in the raw materials,12H forms first,and then coexists with 21H,finally,all 12H converts into 21R in samples.Both phases are plate crystals with flat and smooth edges.Compared with 21R,12H is conducive to improving the density and the cold mechanical properties of materials.After firing at 1650℃in the nitrogen atmosphere,with the mass ratio of SiC to MgAl_(2)O_(4) of 6:4,the sample has the cold modulus of rupture of 27 MPa,showing the optimal performance.
文摘本文利用PCR技术扩增了6个野生群体大泷六线鱼线粒体12S r RNA基因的部分序列。在获得的582bp碱基序列中,共检测到314个变异位点,占总位点数的53.95%。34尾个体共定义了16种单倍型,6个群体的单倍型多样性指数为0.40~1.00,核苷酸多样性指数为0.00071~0.10441。中性检验Fu's Fs值为1.19782(P<0.01)。分子变异分析表明:Fst=0.88326(P<0.01),群体间和群体内变异分别为88.33%和11.67%。不同个体间的遗传距离构建的NJ和MP系统树表明,东港和旅顺群体亲缘关系较近,构成一个分支,其他群体构成另一分支。
文摘目的观察喘可治注射液(CKZ)对慢性阻塞性肺疾病(COPD)大鼠肺组织IL-12/IL-12R/STAT4信号通路的影响。方法 50只SD大鼠随机分为正常组,模型组,CKZ高、中、低剂量(CKZ-H、CHZ-M、CKZ-L)组。除正常组外,各组复制COPD大鼠模型,并给予相应药物治疗,观察CKZ对COPD大鼠血清和肺泡灌洗液(BALF)中γ-干扰素(IFN-γ)、白细胞介素12(IL-12)、白细胞介素12受体(IL-12R)以及肺组织信号转导子和转录激活子4(STAT4)m RNA表达的影响。结果喘可治注射液各剂量组肺组织病理形态均有不同程度的改善,且降低COPD大鼠血清和BALF中IFN-γ、IL-12、IL-12R(除CKZ-L组BALF中IL-12R外)水平(P<0.05,P<0.01),可抑制大鼠肺组织STAT4 m RNA的表达(P<0.01,P<0.05)。结论喘可治注射液能一定程度改善COPD大鼠肺组织病理损害,其作用机制可能与其抑制IFN-γ、IL-12、IL-12R表达,干扰IL-12/IL-12R/STAT4信号通路对靶基因的激活,下调STAT4 m RNA表达,进而调节Th1/Th2分化失衡有关。
