Fast Si magic-angle-spinning NMR acquisitions by RAPT-CP Al → Si polarization transfer

Using enhancement of the ²⁷Al central-transition magnetization by applying RAPT prior to ²⁷Al → ²⁹Si cross-polarization, we demonstrate fast acquisition of ²⁹Si one-dimensional MAS and two-dimensional ²⁷Al–²⁹Si HETCOR spectra on a new sialon phase Ba₂Al₃Si₉N₁₃O₅.     

Fluorescent-based single-strand conformation polymorphism/heteroduplex capillary electrophoretic mutation analysis of the P53 gene.

Fluorescent-based single-strand conformation polymorphism (F-SSCP) analysis with capillary electrophoresis (CE) is the most common method for the detection of mutation because of its high sensitivity and resolution. In this study, we prepared an inexpensive linear polyacrylamide (LPA), and successfully applied it to CE-SSCP analysis and tandem CE-SSCP/heteroduplex analysis (HA) of the P53 gene on an ABI capillary genetic analyzer. A comparison of the sieving capabilities of a homemade LPA and commercial polydimethylacrylamide (PDMA) demonstrates that the homemade LPA has a higher resolution, a shorter analysis time, and is more suitable for tandem SSCP/HA than commercial PDMA. To show the usefulness, mutations of P53 gene exon 7 - 8 in 37 tumor samples were investigated by using homemade LPA. The results indicate that 10 mutations were found in 9 of 37 cases; the majority of P53 mutations were missense mutations, and 70% were located in exon 7, which plays an important role in neoplastic progression in human tumorigenesis.     

SSIMS analysis of organics, polymer blends and interfaces

This paper gives a critical review on the applications of ToF SIMS in the areas of polymer additive characterization and in the study of polymer blends and interfaces. Polymer additives can readily be identified by ToF SIMS using their parent molecular ions or characteristic fragments. This analytical capability has been successfully applied to monitor the migration or segregation of additives during polymer processing. ToF SIMS is an ideal analytical tool for the study of polymer blends and interfaces because it is able to provide information on both surface composition and morphology. In combination with other analytical techniques such as AFM and XPS, ToF SIMS chemical imaging capability has opened up new horizons in the investigation of complex polymer blend systems. Finally the main advantages and limitations of ToF SIMS in these application areas are also discussed.     

双齿配体—1,2—C_6H_4SX(X=O,S)的钴化合物~1H NMR研究

以~1H NMR谱学和磁化率对一些含邻苯二硫酚或巯基苯酚配体的钴化合物的磁性作了研究,并讨论了它们的电子结构。     

MgO films grown on yttria-stabilized zirconia by molecular beam epitaxy

MgO films were grown on (0 0 1) yttria-stabilized zirconia (YSZ) substrates by molecular beam epitaxy (MBE). The crystalline structures of these films were investigated using X-ray diffraction and transmission electron microscopy. Growth temperature was varied from 350 to 550 °C, with crystalline quality being improved at higher temperatures. The MgO films had a domain structure: (1 1 1)[1 1 2¯]_MgO(0 0 1)[1 0 0]_YSZ with four twin variants related by a 90° in-plane rotation about the [1 1 1]_MgO axis. The observed epitaxial orientation was compared to previous reports of films grown by pulsed laser deposition and sputtering and explained as resulting in the lowest interface energy.     

The honeycomb network structure of poly[[[μ2‐1,3‐bis(1H‐benzimidazol‐2‐yl)benzene‐κ2N3:N3′](μ2‐terephthalato‐κ2O:O′)zinc(II)] ethanol solvate]

The terephthalate dianion and the bis(imidazolyl)benzene ligand of the title compound, {[Zn(C₈H₄O₄)(C₂₀H₁₄N₄)]·C₂H₆O}_n, each bridges two adjacent zinc centers, resulting in a layer‐type coordination polymer; the zinc center shows tetrahedral coordination. The disordered ethanol solvent molecules occupy the spaces between the layers and are hydrogen bonded to the layers. The two symmetry‐independent dianions lie on different inversion sites.     

铁羰基络合物制备的一氧化碳加氢催化剂的研究

本文采用Ｆｅ＿３（ＣＯ）＿（１２）制备担载型络合物催化剂。采用程序升温反应技术考察了这类催化剂（ＣＯ＋Ｈ＿２）的反应性能，井使用紫外漫反射光谱和穆斯堡尔谱对催化剂进行了表征。经２５０℃和１５０℃还原的Ｆｅ／γ－Ａｌ＿２Ｏ＿３催化剂不仅活性远远高于４５０℃还原的Ｆｅ／γ－Ａｌ＿２Ｏ＿３，而且前者在反应过程中有乙烯和乙烷生成，后者则只有甲烷生成。经２５０℃还原的Ｆｅ／分子筛催化剂的活性高于４５０℃还原的Ｆｅ／分子筛催化剂，而且前者在反应过程中有乙烯、乙烷和丙烯生成，后者则只有甲烷生成。紫外漫反射谱和穆斯堡尔谱结果表明：较温和条件下活化的催化剂上有金属于属键骨架的存在。     

Effect of drug-loading methods on drug load, encapsulation efficiency and release properties of alginate/poly-L-arginine/chitosan ternary complex microcapsules

The drug-loaded alginate/poly-L-arginine/chitosan ternary complex microcapsules were prepared by mixing method, absorption method and the combined method of mixing and absorption, respectively. The effect of drug-loading methods on drug load, the encapsulation efficiency and the release properties of the complex microcapsules were investigated. The results showed that the absorption process is a dominating factor to greatly increase the drug load of Hb into microcapsules. Upon loading Hb into microcapsules by combined method of mixing and absorption, the drug load (19.9%) is up to the maximum value, and the encapsulation efficiency is 93.8%. Moreover, the drug release is a zero-order kinetics process for the ternary complex microcapsules made by mixing. For the complex microcapsules made by absorption, the drug release is a first-order kinetics. However, for the complex microcapsules made by combining the mixing and the absorption, the drug release obeys a first-order kinetics during the first eighteen hours, changing afterwards to a zero-order kinetics process. Effect of drug-loading methods on drug load and encapsulation efficiency of alginate/poly-L-arginine/chitosan ternary complex microcapsules.