Mesoporous molecular series Ti-KIT-1 samples were prepared by three different post-handling methods using Ti(OEt)4 as the Ti source and KIT-1 as the support.The three post-synthetic methods were impregnated method,gra...Mesoporous molecular series Ti-KIT-1 samples were prepared by three different post-handling methods using Ti(OEt)4 as the Ti source and KIT-1 as the support.The three post-synthetic methods were impregnated method,grafting method and colloidal method.The Ti-KIT-1 samples were characterized by FT-IR,DRS,XRD,TG-DSC and physical adsorption-desorption of nitrogen.Experimental results showed that the Ti-KIT-1 samples remained the original mesoporous structure with a smaller specific BET surface area compared to the parent KIT-1 sieve.DRS and FT-IR indicate the existence of tetrahedral titanium(Ⅳ),TG-DSC and chemical analyse method proved that TiO2 weight percentage of grafting sample is much more than impregnated and colloidal samples.The grafting method is a good post-handling method that can effectively make use of a titanium source and promise the original mesoporous structure.展开更多
以全硅介孔分子筛H-KIT-1为载体,异丙醇铝为铝源,通过后合成法制备出不同铝含量的Al-KIT-1介孔分子筛,用XRD、低温N_(2)吸附-脱附、^(27)Al MAS NMR、TG-DTG对样品的结构和铝的存在形式进行了表征,用常温下吸附氨测量了表面酸量,并用对...以全硅介孔分子筛H-KIT-1为载体,异丙醇铝为铝源,通过后合成法制备出不同铝含量的Al-KIT-1介孔分子筛,用XRD、低温N_(2)吸附-脱附、^(27)Al MAS NMR、TG-DTG对样品的结构和铝的存在形式进行了表征,用常温下吸附氨测量了表面酸量,并用对苯二酚与叔丁醇的烷基化反应评价样品的催化活性。实验结果表明:样品Al-KIT-1仍保留母体H-KIT-1的介孔结构特征,且铝大多以骨架四面体铝的形式存在。样品的催化活性不仅与其表面酸量有关,而且还与其比表面积和孔容有关。样品Al-KIT-1(20)具有规整的介孔结构,其比表面积和孔容较大,表面酸量较高,表现出最好的催化性能,在150℃下反应4 h,对苯二酚的转化率为78.9%,产物2-叔丁基-1,4-苯二酚和2,6-二叔丁基-1,4-苯二酚的得率分别为9.3%和74.7%。展开更多
Approximately 80%-95%of gastrointestinal stromal tumors(GISTs)show positive staining for KIT,while the other 5%-20%show negative staining.If the tumor is negative for KIT,but is positive for CD34,a histological diagno...Approximately 80%-95%of gastrointestinal stromal tumors(GISTs)show positive staining for KIT,while the other 5%-20%show negative staining.If the tumor is negative for KIT,but is positive for CD34,a histological diagnosis is possible.However,if the tumor is negative for KIT,CD34,S-100,and SMA,a definitive diagnosis is often challenging.Recently,Discovered on GIST-1(DOG1)has received considerable attention as a useful molecule for the diagnosis of GIST.DOG1,a membrane channel protein,is known to be overexpressed in GIST.Because the sensitivity and specificity of DOG1 are higher than those of KIT,positive staining for DOG1has been reported,even in KIT-negative GISTs.KITnegative GISTs most commonly arise in the stomach and are mainly characterized by epithelioid features histologically.We describe our experience with a rare case of a KIT-negative GIST of the stomach that was diagnosed by positive immunohistochemical staining for DOG1 in a patient who presented with severe anemia.Our findings suggest that immunohistochemical staining for DOG1,in addition to gene analysis,is useful for the diagnosis of KIT-negative tumors that are suspected to be GISTs.展开更多
文摘Mesoporous molecular series Ti-KIT-1 samples were prepared by three different post-handling methods using Ti(OEt)4 as the Ti source and KIT-1 as the support.The three post-synthetic methods were impregnated method,grafting method and colloidal method.The Ti-KIT-1 samples were characterized by FT-IR,DRS,XRD,TG-DSC and physical adsorption-desorption of nitrogen.Experimental results showed that the Ti-KIT-1 samples remained the original mesoporous structure with a smaller specific BET surface area compared to the parent KIT-1 sieve.DRS and FT-IR indicate the existence of tetrahedral titanium(Ⅳ),TG-DSC and chemical analyse method proved that TiO2 weight percentage of grafting sample is much more than impregnated and colloidal samples.The grafting method is a good post-handling method that can effectively make use of a titanium source and promise the original mesoporous structure.
文摘以全硅介孔分子筛H-KIT-1为载体,异丙醇铝为铝源,通过后合成法制备出不同铝含量的Al-KIT-1介孔分子筛,用XRD、低温N_(2)吸附-脱附、^(27)Al MAS NMR、TG-DTG对样品的结构和铝的存在形式进行了表征,用常温下吸附氨测量了表面酸量,并用对苯二酚与叔丁醇的烷基化反应评价样品的催化活性。实验结果表明:样品Al-KIT-1仍保留母体H-KIT-1的介孔结构特征,且铝大多以骨架四面体铝的形式存在。样品的催化活性不仅与其表面酸量有关,而且还与其比表面积和孔容有关。样品Al-KIT-1(20)具有规整的介孔结构,其比表面积和孔容较大,表面酸量较高,表现出最好的催化性能,在150℃下反应4 h,对苯二酚的转化率为78.9%,产物2-叔丁基-1,4-苯二酚和2,6-二叔丁基-1,4-苯二酚的得率分别为9.3%和74.7%。
文摘Approximately 80%-95%of gastrointestinal stromal tumors(GISTs)show positive staining for KIT,while the other 5%-20%show negative staining.If the tumor is negative for KIT,but is positive for CD34,a histological diagnosis is possible.However,if the tumor is negative for KIT,CD34,S-100,and SMA,a definitive diagnosis is often challenging.Recently,Discovered on GIST-1(DOG1)has received considerable attention as a useful molecule for the diagnosis of GIST.DOG1,a membrane channel protein,is known to be overexpressed in GIST.Because the sensitivity and specificity of DOG1 are higher than those of KIT,positive staining for DOG1has been reported,even in KIT-negative GISTs.KITnegative GISTs most commonly arise in the stomach and are mainly characterized by epithelioid features histologically.We describe our experience with a rare case of a KIT-negative GIST of the stomach that was diagnosed by positive immunohistochemical staining for DOG1 in a patient who presented with severe anemia.Our findings suggest that immunohistochemical staining for DOG1,in addition to gene analysis,is useful for the diagnosis of KIT-negative tumors that are suspected to be GISTs.
