Bioadhesive characteristics of chitosan microspheres to the mucosa of rat small intestine

Chitosan (Chi) microspheres were examined in vitro and in vivo in terms of their bioadhesive characteristics to the mucosa of rat small intestine. Chi was labeled with fluorescein isothiocyanate (FITC), and the microspheres (FTC-MS) were prepared by the dry-in-oil method using the obtained fluorescein thiocarbamyl-chitosan (FTC-Chi). FTC-MS with a mean diameter of 27 μm and size distribution of a few micrometers to several tens of micrometers was used for the bioadhesion experiment. FTC-MS exhibited a tendency to adhere to each part of the small intestine to a greater extent than dissolved FTC-Chi, and the ratio of adhering FTC-MS increased as the amount of added FTC-MS decreased. FTC-MS showed slower transit following intraduodenal injection than oral administration. Following the intraduodenal injection of FTC-MS, more than half remained in the upper or middle part of the small intestine for over 8 h. Further, insulin-containing chitosan microspheres with a mean diameter of 20 μm and size distribution of 5 μm to 45 μm were checked in situ for drug absorption, but intraduodenal or intraileal application hardly gave any decrease in plasma glucose level at a very high dose. The present chitosan microsphere system showed good adhesion to the intestinal mucosa, but scarcely facilitated absorption of insulin.     

A 2D–3D integrated tabletop environment for multi‐user collaboration

This paper proposes a novel tabletop display system for natural communication and flexible information sharing. The proposed system is specifically designed to integrate two‐dimensional (2D) and three‐dimensional (3D) user interfaces by using a multi‐user stereoscopic display, IllusionHole. The proposed system takes awareness into consideration and provides both 2D and 3D information and user interfaces. On the display, a number of standard Windows desktop environments are provided as personal workspaces, as well as a shared workspace with a dedicated graphical user interface. In the personal workspaces, users can simultaneously access existing applications and data, and exchange information between personal and shared workspaces. In this way, the proposed system can seamlessly integrate personal, shared, 2D, and 3D workspaces with conventional user interfaces and effectively support communication and information sharing. To demonstrate the capabilities of the proposed display system, a modeling application was implemented. A preliminary experiment confirmed the effectiveness of this system. Copyright © 2006 John Wiley & Sons, Ltd.     

Comparison of miscibility in poly(N-vinylcarbazole)/polystyrene and polyoxyethylene blends by excimer fluorescence

Summary It is for the first time found that poly(N-vinylcarbazole)(PVCz)/polystyrene (PS) blends have lower miscibility on molecular level than that of PVCz/polyoxyethylene (PEO) blends. This is obtained from excimer fluorescence properties of PVCz in PVCz (9.1–100%)/PS and PVCz (9.6–100%)/PEO blends. Schematic diagrams of phase-separated structure of the PVCz blends are proposed consistent with emission properties and phase-contrast microscopic images. Received: 8 February 2000/Revised version: 21 March 2000/Accepted: 27 March 2000     

A quantum walk on the half line with a particular initial state

Quantum walks are considered to be quantum counterparts of random walks. They show us impressive probability distributions which are different from those of random walks. That fact has been precisely proved in terms of mathematics and some of the results were reported as limit theorems. When we analyze quantum walks, some conventional methods are used for the computations; especially, the Fourier analysis has played a role to do that. It is, however, compatible with some types of quantum walks (e.g., quantum walks on the line with a spatially homogeneous dynamics) and cannot well work on the derivation of limit theorems for all the quantum walks. In this paper, we try to obtain a limit theorem for a quantum walk on the half line by the usage of the Fourier analysis. Substituting a quantum walk on the line for it, we will lead to a possibility that the Fourier analysis is useful to compute a limit distribution of the quantum walk on the half line.     

One‐Step Derivatization of Reducing Oligosaccharides for Rapid and Live‐Cell‐Compatible Chelation‐Assisted CuAAC Conjugation

We report a new reagent for the functionalization of unprotected oligosaccharides with a picolyl azide group at the anomeric position for chelation‐assisted copper‐catalyzed alkyne–azide cycloaddition (CuAAC) glycoconjugation. We show that oligosaccharides functionalized with this moiety react with an apparent second‐order rate constant of 193 m ^?1 s^?1 and can be used to functionalize biomolecules bearing alkyne moieties introduced through metabolic labeling, including in live cells.     

绿色溶剂γ-戊内酯中果糖催化转化为5-羟甲基糠醛

通过生物质衍生糖的酸催化转化制备生物质基平台化合物5-羟甲基糠醛受到关注。常用又有效的溶剂包括离子液体和二甲基亚砜等,但这些溶剂黏度高,易造成空气污染。以γ-戊内酯作为溶剂,研究果糖催化转化为5-羟甲基糠醛的绿色过程,系统研究酸催化剂种类、反应温度、催化剂用量、果糖初始浓度及底物种类等对5-羟甲基糠醛产率的影响。通过反应条件的优化,以HCl溶液为催化剂,在果糖初始质量浓度2%、反应温度100℃和反应时间30 min条件下,5-羟甲基糠醛产率为93.5%。5-羟甲基糠醛产率随果糖初始添加量的增加而呈下降趋势,但果糖初始质量浓度为10%时,5-羟甲基糠醛产率仍保持约90%,表明γ-戊内酯是一种将果糖催化转化为5-羟甲基糠醛的优良绿色溶剂。     

Identification of 3,4-Dihydro-2H,6H-pyrimido[1,2-c][1,3]benzothiazin-6-imine Derivatives as Novel Selective Inhibitors of Plasmodium falciparum Dihydroorotate Dehydrogenase

Plasmodium falciparum’s resistance to available antimalarial drugs highlights the need for the development of novel drugs. Pyrimidine de novo biosynthesis is a validated drug target for the prevention and treatment of malaria infection. P. falciparum dihydroorotate dehydrogenase (PfDHODH) catalyzes the oxidation of dihydroorotate to orotate and utilize ubiquinone as an electron acceptor in the fourth step of pyrimidine de novo biosynthesis. PfDHODH is targeted by the inhibitor DSM265, which binds to a hydrophobic pocket located at the N-terminus where ubiquinone binds, which is known to be structurally divergent from the mammalian orthologue. In this study, we screened 40,400 compounds from the Kyoto University chemical library against recombinant PfDHODH. These studies led to the identification of 3,4-dihydro-2H,6H-pyrimido[1,2-c][1,3]benzothiazin-6-imine and its derivatives as a new class of PfDHODH inhibitor. Moreover, the hit compounds identified in this study are selective for PfDHODH without inhibition of the human enzymes. Finally, this new scaffold of PfDHODH inhibitors showed growth inhibition activity against P. falciparum 3D7 with low toxicity to three human cell lines, providing a new starting point for antimalarial drug development.     

Majorana Edge Modes of Superfluid 3He A-?and?B-Phases

Motivated by a recent experiment on the superfluid ³He confined in a thin slab, we discuss the Majorana edge modes under the experimental situation. We solve the quasi-classical Eilenberger equation, which is quantitatively reliable, to evaluate several observables, such as local density of states, mass current for the A-phase, and spin current for the B-phase. On the basis of the quantitative calculation, we propose several experiments to check the existence of the Majorana modes.     

Rapid detection of homologously integrated DNA fragments and accurate quantitation of their copy number in transgenic Aspergillus oryzae by PCR

A simple and rapid method for the analysis of artificially introduced DNA fragments has been developed using competitive PCR and long and accurate PCR. The locus and the copy number of the DNA fragments in each Aspergillus oryzae transformant could be detected more rapidly and accurately by this method than by the conventional Southern hybridization method.