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111.
Well‐defined drug‐conjugated amphiphilic A2B2 miktoarm star copolymers [(PCL)2‐(PEG)2‐D] were prepared by the combination of controlled ring‐opening polymerization (CROP) and “click” reaction strategy. First, bromide functionalized poly(ε‐caprolactone) (PCL‐Br) with double hydroxyl end groups was synthesized by the CROP of ε‐caprolactone using 2,2‐bis(bromomethyl)propane‐1,3‐diol as a difunctional initiator in the presence of Sn(Oct)2 at 110 °C. Next, the bromide groups of PCL‐Br were quantitatively converted to azide form by NaN3 to give PCL‐N3. Subsequently, the end hydroxyl groups of PCL‐N3 were capped with ibuprofen as a model drug at room temperature. Finally, copper(I)‐catalyzed cycloaddition reaction between ibuprofen‐conjugated PCL‐N3 and slightly excess alkyne‐terminated poly(ethylene glycol) (A‐PEG) led to ibuprofen‐conjugated A2B2 miktoarm star copolymer [(PCL)2‐(PEG)2‐D]. The excess A‐PEG was removed by dialysis. 1H NMR, FTIR and SEC analyzes confirmed the expected miktoarm star architecture. These amphiphilic miktoarm star copolymers could self‐assemble into multimorphological aggregates in aqueous solution, which were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In addition, the drug‐loading capacity of these drug‐conjugated miktoarm star copolymers as well as their nondrug‐conjugated analogs were also investigated in detail. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009  相似文献   
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Nucleic acids dye Goldview is widely used in agarose gel electrophoresis (AGE). However, in this study, a sample of multiplasmid DNA (multi-pDNA) stained with Goldview analyzed by AGE showed its instability at low temperature. Three types of DNA samples were analyzed, including linear DNA (ladder), single-plasmid DNA (single-pDNA), and multi-pDNA, electrophoretic conditions were optimized by adjusting the dye, the buffer, and the temperature (1–50°C). The results showed that the light intensity of Gelred is 2.2-times higher than that of Goldview in staining multi-pDNA. Compared with the single-pDNA and the linear DNA, the multi-pDNA stained with Goldview was greatly affected by temperature. This short communication indicated that Gelred is a highly applicable dye for analyzing multiplasmid samples. The degree and the way of binding of Goldview to multi-pDNA are greatly affected by temperature.  相似文献   
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针对瞬态光谱检测中对CCD线扫描速度要求高的特点,提出一种基于面阵CCD的瞬态光谱检测方法。该方法通过改变面阵CCD的电荷转移方式,以实现基于面阵CCD的高速线扫描。为了探究此方法的可行性,初步通过改变线阵CCD的电荷转移方式,建立了基于线阵CCD的单点超快探测系统。在发光二极管(light emitting diode,LED)光脉冲探测实验中,系统分别工作在单点超快探测模式和正常模式下。测试结果表明,基于线阵CCD的单点超快探测方法是可行的,单点探测速率可达20MHz。从而在理论上证明,通过改变CCD电荷转移方式以实现基于面阵CCD的瞬态光谱检测也是切实可行的。  相似文献   
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IntroductionThemotionoftheinviscid,irrotationalandincompressiblefluidinacylindricalcontainerwithradiusaisgovernedbyFig.1Sloshofaliquidinacylindricalcontainer2=0  (inV),(1)r=0  (onr=a),(2)z=0  (onz=-h),(3)ηt+·η=z  (onz=η),(4)t+12|…  相似文献   
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Adaptive mesh refinement (AMR) shows attractive properties in automatically refining the flow region of interest, and with AMR, better prediction can be obtained with much less labor work and cost compared to manually remeshing or the global mesh refinement. Cartesian AMR is well established; however, AMR on hybrid unstructured mesh, which is heavily used in the high‐Reynolds number flow simulation, is less matured and existing methods may result in degraded mesh quality, which mostly happens in the boundary layer or near the sharp geometric features. User intervention or additional constraints, such as freezing all boundary layer elements or refining the whole boundary layer, are required to assist the refinement process. In this work, a novel AMR strategy is developed to handle existing difficulties. In the new method, high‐order unstructured elements are first generated based on the baseline mesh; then the refinement is conducted in the parametric space; at last, the mesh suitable for the solver is output. Generating refined elements in the parametric space with high‐order elements is the key of this method and this helps to guarantee both the accuracy and robustness. With the current method, 3‐dimensional hybrid unstructured mesh of huge size and complex geometry can be automatically refined, without user intervention nor additional constraints. With test cases including the 2‐dimensional airfoil and 3‐dimensional full aircraft, the current AMR method proves to be accurate, simple, and robust.  相似文献   
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判断中国经济社会发展规划是否科学合理的标准包括:(1)是否体现以人民为中心的发展理念;(2)是否符合基本国情;(3)是否坚持公共利益优先;(4)是否发挥了市场在资源配置中的决定性作用;(5)是否旨在针对外部性(市场失灵)提供公共产品;(6)是否建立了中央政府和地方政府以及政府与民间激励相容机制;(7)是否将地方政府自由裁量权限定在了合理区间。以上七条不仅是判断中国以往包括“十三五”规划在内的各种经济社会发展规划是否科学合理的标准,同时也是今后制定新的经济社会发展规划特别是业已启动的“十四五”规划编制应遵循的基本原则。  相似文献   
120.
Main observation and conclusion This paper describes the first case of a reductive coupling reaction with indene,a non-heteroatom olefin used as a reducing agen...  相似文献   
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