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111.
Masakazu Yoshikawa Katsunori Koso Kyoichi Yonetani Satoshi Kitamura Satoshi Kimura 《Journal of polymer science. Part A, Polymer chemistry》2005,43(2):385-396
Molecularly imprinted polymeric membranes were prepared from various oligopeptide tweezers by the adoption of N‐α‐tert‐butoxycarbonyl‐D ‐tryptophan (Boc‐D ‐Trp) or N‐α‐tert‐butoxycarbonyl‐L ‐tryptophan (Boc‐L ‐Trp) as a print molecule. The chiral recognition ability of the formed molecular recognition sites was dependent on the absolute configuration of the print molecule adopted in the membrane preparation (molecular imprinting) process, whereas the candidate oligopeptide tweezers consisted of the L ‐amino acid residues. In other words, the membranes imprinted by the D ‐isomer recognized the D ‐isomer in preference to the corresponding L ‐isomer, and vice versa. The affinity constant between the target molecule and the chiral recognition site from the oligopeptide tweezers was higher than that from a single‐strand oligopeptide derivative. Those membranes selectively transported the enantiomer, which was preferentially incorporated into the membrane by dialysis. The permselectivities for these membranes exceeded their adsorption selectivities. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 385–396, 2005 相似文献
112.
We applied a time-resolved small-angle neutron scattering technique to the vesicle system of dimyristoylphosphatidylcholine for the first time to determine lipid kinetics. The observed kinetics could be explicitly represented by a simple model that includes two independent kinetic parameters, i.e., the rates of transbilayer and interbilayer exchange. This technique is perfectly suited for the determination of lipid exchange kinetics in equilibrium and applicable to evaluation of the activity of the factors relevant to lipid migration, such as translocase and lipid transfer proteins. 相似文献
113.
Spontaneous Formation of Microgroove Arrays on the Surface of p‐Type Porous Silicon Induced by a Turing Instability in Electrochemical Dissolution 下载免费PDF全文
Prof. Dr. Kazuhiro Fukami Tomoko Urata Prof. Dr. Katharina Krischer Prof. Dr. Naoya Nishi Prof. Dr. Tetsuo Sakka Dr. Atsushi Kitada Prof. Dr. Kuniaki Murase 《Chemphyschem》2015,16(8):1613-1618
Self‐organization plays an imperative role in recent materials science. Highly tunable, periodic structures based on dynamic self‐organization at micrometer scales have proven difficult to design, but are desired for the further development of micropatterning. In the present study, we report a microgroove array that spontaneously forms on a p‐type silicon surface during its electrodissolution. Our detailed experimental results suggest that the instability can be classified as Turing instability. The characteristic scale of the Turing‐type pattern is small compared to self‐organized patterns caused by the Turing instabilities reported so far. The mechanism for the miniaturization of self‐organized patterns is strongly related to the semiconducting property of silicon electrodes as well as the dynamics of their surface chemistry. 相似文献
114.
Inside Cover: Spontaneous Formation of Microgroove Arrays on the Surface of p‐Type Porous Silicon Induced by a Turing Instability in Electrochemical Dissolution (ChemPhysChem 8/2015) 下载免费PDF全文
115.
Anuj Kumar Yuvraj Singh Negi Veena Choudhary Nishi Kant Bhardwaj 《International Journal of Polymer Analysis and Characterization》2017,22(2):139-151
Cellulose nanocrystal-reinforced poly(vinyl alcohol)/silica glass hybrid scaffolds were fabricated using the freeze-drying method. In this study, we develop molecular-level-based hybrid scaffolds with possible bioactivity behavior by adding silica sol–gel. The results showed a highly porous structure and a significant improvement in mechanical performance (stiffness) of hybrid scaffolds with an increased content of cellulose nanocrystals followed by the addition of silica-based bioactive glass. In vitro cell study with MC3T3-E1 cells on hybrid scaffolds for 1 and 3 days revealed good cell adhesion and growth. Thus, the obtained hybrid scaffold may be a competitive candidate for bone tissue engineering applications. 相似文献
116.
In this paper we propose a new problem of finding the maximal bi-connected partitioning of a graph with a size constraint (MBCPG-SC). With the goal of finding approximate solutions for the MBCPG-SC, a heuristic method is developed based on the open ear decomposition of graphs. Its essential part is an adaptation of the breadth first search which makes it possible to grow bi-connected subgraphs. The proposed randomized algorithm consists of growing several subgraphs in parallel. The quality of solutions generated in this way is further improved using a local search which exploits neighboring relations between the subgraphs. In order to evaluate the performance of the method, an algorithm for generating pseudo-random unit disc graphs with known optimal solutions is created. Computational experiments have also been conducted on graphs representing electrical distribution systems for the real-world problem of dividing them into a system of fault tolerant interconnected microgrids. The experiments show that the proposed method frequently manages to find optimal solutions and has an average error of only a few percent to known optimal solutions. Further, it manages to find high quality approximate solutions for graphs having up to 10,000 nodes in reasonable time. 相似文献
117.
118.
Uyama A Yamazoe S Shigematsu S Morimoto M Yokojima S Mayama H Kojima Y Nakamura S Uchida K 《Langmuir : the ACS journal of surfaces and colloids》2011,27(10):6395-6400
By alternate UV and visible light irradiation, reversible topographical changes were observed on a newly synthesized diarylethene microcrystalline surface between the rough crystalline surface of an open-ring isomer and flat eutectic surfaces. The contact angle changes of a water droplet between 80° and 150° and peak intensities changes of the open-ring isomer in XRD patterns within 2 h of repeating cycle were observed. The results indicated that reversibly photogenerated rod-shaped crystals on the surface were produced based on the lattice of the open-ring isomer crystals in the subphase. 相似文献
119.
Kuwamura N Kitano K Hirotsu M Nishioka T Teki Y Santo R Ichimura A Hashimoto H Wright LJ Kinoshita I 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(38):10708-10715
Interchange between the nickel +2 and +3 oxidation states precisely controls the reversible rearrangement of the tris(2-pyridylthio)methanide (tptm) ligand in the organometallic nickel(II) complex [{Ni(μ-Br)-(tptm)}(2)] (2). Oxidation of 2 first gives the corresponding Ni(III) complex [{Ni(μ-Br)(tptm)}(2)][PF(6)](2) (4). However, in solution the tptm ligand in 4 slowly undergoes a rearrangement, in which the N and S atoms of one of the pyridylthiolate arms exchange Ni and C bonding partners, thereby resulting in an "N,S-confused" isomer of tptm in the product, [NiBr(bpttpm)]PF(6) (5; bpttpm= bis(2-pyridylthio)(2-thiopyridinium)-methyl). Reduction of 5 reverses this ligand rearrangement and 2 is reformed quantitatively. The individual steps involved in these unusual ligand rearrangements were investigated by a number of methods, including voltammetric analysis, and a mechanism for this process is proposed. X-ray crystal structure determinations of the key compounds 2, 4 and 5 have been obtained. 相似文献
120.
Yukiko IioMakoto Yamaoka Masayoshi JinYoshitaka Nakamura Takahide Nishi 《Tetrahedron: Asymmetry》2011,22(3):323-328
Herein we report the asymmetric synthesis of α,α-disubstituted α-amino alcohol derivatives 22, 25 and 26, key intermediates of a novel immunomodulator, using Seebach’s method. This synthetic method can be applied to the large scale synthesis of chiral sphingosine 1-phosphate-1 (S1P1) receptor agonists, with significant improvements to the previously reported method with regard to the reaction temperature. 相似文献