968 resultados para D., D. S. C. D. L. T.


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The solution- and melt-phase photochemistry of four trans-benzylidene-d,l-piperitones (1) has been investigated under a variety of conditions. The 1 undergo trans reversible cis isomerization to establish a quasi photostationary state. Further irradiation leads to 2 via oxidative ring closure. Conspicuously absent are dimers (obtained upon irradiation of the neat crystals) and the plausible Norrish Type II photoproducts, 3. Although 1c yields 2c, no evidence for the alternative cyclization route to 2a (requiring loss of HCl) has been observed. Rationalizations for the transformations are presented. The structure of 2b has been determined unambiguously from X-ray crystallographic analysis.

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聚(ε┐己内酯)/聚(d,l┐丙交酯)共混物膜在酶促降解过程中的形态变化张杰甘志华*梁奇志景遐斌(吉林工业大学理学院应用化学系长春)(中国科学院长春应用化学研究所长春130022)关键词聚己酸内酯-聚丙交酯共混物,酶促降解,形态1997-10-30收…

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采用一种新型的稀土配位化合物Y(CF3COO)3/Al(i-Bu)3为催化剂,制备了不同组成的ε-己内酯/d,l-丙交酯共聚物,并用GPC、NMR和DSC表征了共聚物的结构.结果表明通过改变初始投料中两种单体的比例,可以调节共聚酯的化学结构,而共聚物的形态则受结构影响很大.

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Human papillomavirus (HPV) is the leading cause of cervical cancer and the most prevalent sexually transmitted disease worldwide. HPV vaccines require a multi-dose regimen to provide immunity, contributing to low patient compliance. We addressed this problem by formulating biodegradable poly(D,L-lactic-co-glycolic acid) (PLGA) microparticles and assessing their viability for use in controlled-release vaccines. We hypothesized that we could alter fabrication parameters to produce 1-10 μm microparticles in order to encapsulate ovalbumin (OVA) and HPV virus-like particles (VLPs). Microparticles were fabricated using a double emulsion method and used to elicit an immune response in JAWSII cells. Our results contribute to knowledge of vaccine delivery mechanisms and controlled-release technology, and could contribute to the creation of a viable controlled-release HPV vaccine.

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[Mazarinade. 1649]

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Comprend : Penses de Montesquieu adressées à son fils, tirées d'un manuscrit que l'on dit être original ; Madrigal et épigramme sur la Troade de Pradon

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Comprend : Penses de Montesquieu adressées à son fils, tirées d'un manuscrit que l'on dit être original ; Madrigal et épigramme sur la Troade de Pradon

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Comprend : Penses de Montesquieu adressées à son fils, tirées d'un manuscrit que l'on dit être original ; Madrigal et épigramme sur la Troade de Pradon

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