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排序方式: 共有212条查询结果,搜索用时 10 毫秒
191.
聚酰胺-胺(PAMAM)树状大分子对甲氨蝶呤的包合及缓释研究 总被引:3,自引:0,他引:3
以甲氨蝶呤(MTX)为模型药物,研究了G5.0PAMAM树状大分子对其包合和释放,并用13CNMR对PAMAM-MTX包合物进行了表征.UV-Vis研究结果表明,1个G5.0PAMAM树状大分子能包合27个MTX分子,体外释放研究表明,在37℃,pH=7.4的10mmol/LTris-HCl缓冲溶液中G5.0PAMAM树状大分子对MTX具有明显的缓释作用. 相似文献
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193.
在Zn2+离子与聚酰胺-胺(PAMAM)树形分子配位的基础上,制备了稳定的PAMAM树形分子包覆的ZnS量子点(quantum dots,QDs),并用紫外-可见吸收光谱(UV-Vis)和荧光发射光谱进行了表征。结果表明,Zn2+离子能与PAMAM树形分子发生配位络合作用,且饱和配位时间为6h;在波长365nm紫外光的激发下,PAMAM树形分子包覆的ZnS量子点发射出明亮的蓝色荧光,荧光发射峰约位于450nm。最后,将得到的PAMAM树形分子包覆的ZnS量子点纳米复合材料应用于锡纸上潜指纹的荧光标记成像研究,发现指纹可以被清晰识别,呈现明亮的蓝色荧光指纹。 相似文献
194.
PVP and G1.5 PAMAM dendrimer co-mediated silver nanoparticles of smaller than 5 nm in diameter were prepared using H2 as reducing agent. With the TEM micrograph, it was found that the molar ratios of PVP and G1.5 PAMAM dendrimer have significant effect in the morphology and size distribution of silver nanoparticles. The reaction rate (fitting a first-order equation) was strongly influenced by the molar ratios of PVP and G1.5 PAMAM dendrimer and the reaction temperature. From the UV-Vis spectra of an aqueous solution of silver nanoparticles, they could be stored for at least 2 months without coagulation at room temperature. 相似文献
195.
PAMAM树形分子为模板低温制备纳米硫化锌空心球 总被引:4,自引:0,他引:4
Hollow ZnS spheres have been prepared in the presence of generation 3.5 poly (amidoamine) dendrimers with surface ester groups (G3.5-COOCH3 PAMAM dendrimer) as synthetic matrix template. The products obtained were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-Vis absorption. TEM studies show that the hollow spheres with diameters ranging from 80 to 100 nm are prepared. The range of wall thickness was estimated to be about 20~30 nm. It was found that the concentration of PAMAM dendrimer had a significant influence on the formation of hollow ZnS spheres. The possible formation mechanism of the hollow spherical structure is also discussed. 相似文献
196.
Nan-Young Lee 《Tetrahedron letters》2005,46(36):6063-6066
Synthetic glycoconjugated dendrimers have emerged as important functional glycomimetics for studying multivalency effects in the cell-cell communications. We report herein, a synthetic route to functionalized glycodendrimers with scyllo-inositol as the scaffold, which have a directed geometry; one side of the dendrimers is designed for ready attachment to the AFM probe/solid matrix, and the other to have a varying number of a sugar. 相似文献
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198.
This paper presents the photophysical and photochemical characteristics of four new poly(amidoamine) dendrimers of zero and second generation whose periphery has been modified with 1,8-naphthalimide units. Nitro- and allylamino groups have been used as substitutents at the C-4 position of the 1,8-naphthalimide fluorophores. The discussion is focused on the photodegradation of the dendrimers in N,N-dimethylformamide and dioxan solutions. Investigations have shown that the photodegradation of the dendrimers with 4-nitro substituted 1,8-naphthalimide proceed with yellow colour development in the solvent while no colour changes followed the same process in dendrimers with allylamino group substituent. The results also show that the photostability of the dendrimers depends on their generation. 相似文献
199.
200.
WANG Yongjian LIU Jianfeng DUO Jia YU Yaoting 《科学通报(英文版)》2005,50(21):2432-2435
Polyamidoamine (PAMAM) is a type of macromolecule having a definite chemical structure and a large number of terminal functional groups. The synthetic approach of the adsorbent with high adsorption capacity involved arching of PAMAM onto cellulose beads by reaction with epichlorohydrin. The product thus prepared had a large number of amino groups of 2.94 mmol/g derived from 0.23 mmol/g epoxy groups on cellulose beads. This method presents an effective method for the preparation of high-loading adsorbents. 相似文献