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81.
不同颜色体系的UV丝印油墨中光引发体系的选择   总被引:1,自引:0,他引:1  
使用紫外-可见分光光度计测得了黄、蓝、橙、紫4种颜料的紫外吸收图谱;在模型化的丝印油墨配方中改变光引发剂的种类,运用指压法和指抠法研究了多种光引发剂对含有这4种颜料的UV油墨的引发速度的影响。结果表明不同颜色的颜料对紫外光的吸收区域和吸收强度是不同的。对于黄色油墨,907的引发效果最佳;对于蓝色油墨,907+ITX+EDAB和910+ITX+EDAB都具有很高的引发速度;而对于橙色油墨和紫色油墨,907+ITX+EDAB则是速度最高的引发剂组合。  相似文献   
82.
The high melting point of poly(1,4‐cyclohexanedicarboxylic anhydride) [poly(CHDA)] is a disadvantage, in that it is intractable in the melting process of a drug delivery system. This report relates to diols introduced into the polyanhydride main chain to decrease its melting point. Various poly(ester anhydride)s containing ethylene glycol, 1,3‐propanediol, 1,4‐butanediol, or 1,6‐hexandiol [poly(CHDA–XDO)] were synthesized by the esterification reaction and melt polycondensation. FTIR, DSC, WAXD, and intrinsic viscosity of polymers were recorded and hydrolytic degradation, as well as in vitro drug delivery, was conducted. The results show that the samples are stable in an anhydrous environment at room temperature and degrade in water following a surface erosion mechanism. The degradation period of poly(CHDA–XDO) ranged from 130 to 320 h as a result of the different diols and amounts of XDO introduced. The in vitro drug delivery gave 130–350 h of stable delivery along with the typical surface erosion mechanism. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2509–2514, 2002  相似文献   
83.
A controlled release profile of salicylic acid (SA) for transdermal administration has been developed. Poly (vinyl alcohol) (PVA) and Poly(vinyl alcohol)/Poly(vinyl pyrrolidone) (PVP) blended preparations were used to prepare the membranes by solvent‐casting technique. The release of the drug from the membranes was evaluated at in vitro conditions. The effects of PVA/PVP (v/v) ratio, pH, SA concentration and temperature were investigated. 60/40 (v/v) PVA/PVP ratio was found to be the best ratio for the SA release. Increase in pH and temperature was observed to increase the transport of SA. Instead of blending PVA with PVP, N‐Vinyl‐2‐pyrrolidone (VP) was grafted onto the PVA and the delivery performance for SA was compared with that of the blended PVA/PVP membranes. Grafted membranes gave higher transport percentages than the blended membranes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1244–1253, 2006  相似文献   
84.
多孔β-TCP陶瓷药物载体结构与性能的影响因素   总被引:1,自引:0,他引:1  
本分析了影响多孔β-TCP陶瓷药物载体结构与性能的因素,确定了制备多孔β-TCP陶瓷药物载体的技术路线和工艺参数。  相似文献   
85.
86.
The chemical composition and quantitative molar ratios among all components of biodegradable polyphosphoester copolymers of DL ‐lactide and ethylphosphate were determined by a comprehensive set of NMR spectroscopic methods. The polyphosphoester copolymers studied were synthesized using condensation polymerization of oligomeric DL ‐lactide prepolymers and ethyl dichlorophosphate. Conclusive identification of the chemical shift patterns of all functional groups in the copolymers required additional NMR methods such as 31P‐NMR and two‐dimensional 1H–1H COSY NMR, in addition to the synthesis and comparative NMR analysis of model compounds possessing identical phosphoester linkages in the polyphosphoester copolymers. For the polymers synthesized using the bulk polycondensation process, 1H–1H COSY NMR analysis revealed the presence of a small amount of side products that were undetected by 1H‐NMR alone. These side reactions most likely occurred between the pendant ethoxy group of the phosphoesters and the hydrogen chloride gas generated in the bulk polycondensation process. 31P‐NMR spectra of the copolymers revealed a consistent triple‐peak pattern characteristic of phosphoesters linked to a racemic mixture of D,L ‐lactides. These results offered new insight into the side reactions occurring in bulk polymerization of polyphosphoesters and provided a powerful tool of characterizing complex biodegradable polymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4021–4031, 2003  相似文献   
87.
TAR RNA is a potential target for AIDS therapy. Ligand-based virtual screening was performed to retrieve novel scaffolds for RNA-binding molecules capable of inhibiting the Tat-TAR interaction, which is essential for HIV replication. We used a "fuzzy" pharmacophore approach (SQUID) and an alignment-free pharmacophore method (CATS3D) to carry out virtual screening of a vendor database of small molecules and to perform "scaffold-hopping". A small subset of 19 candidate molecules were experimentally tested for TAR RNA binding in a fluorescence resonance energy transfer (FRET) assay. Both methods retrieved molecules that exhibited activities comparable to those of the reference molecules acetylpromazine and chlorpromazine, with the best molecule showing ten times better binding behavior (IC50 = 46 microM). The hits had molecular scaffolds different from those of the reference molecules.  相似文献   
88.
A series of pH‐responsive hydrogels were studied as potential drug carriers for the protection of insulin from the acidic environment of the stomach before releasing in the small intestine. Hydrogels based on poly(vinyl alcohol) networks grafted with acrylic acid or methacrylic acid were prepared by a two‐step process. Poly(vinyl alcohol) hydrogels were prepared by gamma ray irradiation (50 kGy) and then followed by grafting either acrylic acid or methacrylic acid onto these poly(vinyl alcohol) hydrogels with subsequent irradiation (5–20 kGy). These graft hydrogels showed pH‐sensitive swelling behavior and were used as carriers for the controlled release of insulin. The in vitro release of insulin was observed for the insulin‐loaded hydrogels in a simulated intestinal fluid (pH 6.8) but not in a simulated gastric fluid (pH 1.2). The release behavior of insulin in vivo in a rat model confirmed the effectiveness of the oral delivery of insulin to control the level of glucose. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 636–643, 2004  相似文献   
89.
Zn-Al-CO_3水滑石晶粒尺寸控制与光屏蔽作用研究   总被引:2,自引:1,他引:2  
在旋转液膜反应器中制备成核浆液 ,通过控制晶化温度制备了不同粒径且晶体结构完整的Zn Al CO3水滑石 (LDHs)。将不同粒径的Zn Al CO3LDHs配成质量分数为 0 0 2 %的水分散液 ,测定在紫外 -可见光范围的透过率 ,结果发现 ,随晶化温度的升高 ,LDHs粒径增大 ,样品对紫外及可见光的阻隔作用增强 ;Zn Al CO3LDHs在不同波长下的吸光度与晶体粒子在a轴和c轴方向的尺寸呈线性关系。由外推法求得了Zn Al CO3LDHs对各波长紫外 -可见光产生屏蔽作用的晶粒尺寸阈值。对波长分别为 2 90、3 2 0、40 0、60 0和 80 0nm光波能够产生屏蔽作用的Zn Al CO3LDHs ,其粒子尺寸在a轴方向需分别大于 3 2 92、3 3 77、3 4 77、3 5 5 6、3 5 79nm ;在c轴方向需分别大于 9 73、12 79、16 47、19 3 5、2 0 2 2nm。  相似文献   
90.
Combinatorial chemistry has proven to be a valuable tool for the development of new compounds. In the pharmaceutical industry, where combinatorial chemistry began, the approach has been instrumental in the high-speed development of new drugs. Due to the overwhelming success of the combinatorial methodology in the pharmaceutical industry, it has been recently applied to materials development. We have recently developed a combinatorial factory capable of preparing and evaluating on the order of 100 organic clear coatings in a day.

One of the most challenging aspects of the creation of the combinatorial factory was the development of the high throughput screening (HTS) methods for the primary coating properties of interest such as optical clarity, abrasion resistance, adhesion, and weatherability. For each property, an entirely new method was developed that allowed for rapid measurement of these properties on very small samples. This paper describes various aspects of the development of these novel measurement systems including the correlation of the HTS methods with conventional, industry standard measurement methods.  相似文献   

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