Photomechanical Switching Behavior of Semi‐Interpenetrating Polymer Network Consisting of Azobenzene‐Carrying Crosslinked Poly(vinyl ether) and Polycarbonate

Summary: A novel semi‐interpenetrating polymer network (semi‐IPN) with photomechanical switching ability was developed by a cationic copolymerization of azobenzene‐containing vinyl ethers in a matrix of a linear polycarbonate (PC). The semi‐IPN film showed reversible deformation upon switching the UV irradiation on and off and responded with unprecedented rapidity. The photomechanical effect is attributed to a reversible change between the highly aggregated and dissociated states of the azobenzene groups.

The reversible UV response of the length of the semi‐IPN film at 25 °C.     

New entry to the Pauson-Khand reaction: trimethylgermyl group at the triple bond terminus as a latent functional group

The Pauson-Khand reaction of enynes possessing a trimethylgermyl group at the alkyne terminus afforded the corresponding bicyclo[3.3.0]octenone and bicyclo[4.3.0]nonenone skeletons in a stereoselective manner. The resulting trimethylgermyl group of the bicyclic compounds was then converted to the iodo group, which was used for further elaboration. Thus, the trimethylgermyl group at the triple bond terminus was shown to be a precursor for other appendages.     

Inhibition assay of yeast cell walls by plasmon resonance Rayleigh scattering and surface-enhanced Raman scattering imaging

We report on plasmon resonance Rayleigh scattering (PRRS) and surface enhanced Raman scattering (SERS) imaging for inhibition assay of yeast cell walls. This assay reveals that the proteins having alkali sensitive linkage bound to β1,3 glucan frameworks in cell walls are involved in SERS activity. The result is further confirmed by comparison of genetically modified cells and wild type cells. Finally, we find that PRRS and SERS spots do not appear on cell walls when daughter cells are enough smaller than parent ones, but appear when size of daughter cells are comparable to parent cells. This finding indicates the relationship between expression of the proteins that generate SERS spots and cell division. These results demonstrate that PRRS and SERS imaging can be a convenient and sensitive method for analysis of cell walls.     

Phospholipid-Modified ODS Monolithic Column for Affinity Prediction of Hydrophobic Basic Drugs to Phospholipids

A phospholipid-modified octadecyl silica (ODS) monolithic column was prepared and its interaction with basic hydrophobic drugs was studied. These drugs are of interest in pharmaceutical research because of their strong interaction with biomembranes. The amount of dimyristoylphosphatidylcholine trapped on the ODS surface was reproducible, and the results of the trinitrobenzenesulfonic acid assay suggested the formation of a monolayer on the surface. Both hydrophobic and electrostatic interactions acted between the model drugs and the phosphatidylcholine. The column was stable for 10 days at least. The column was applied to the affinity screening of basic drugs to phospholipid. Good correlation was obtained between log k and log P for the basic drugs lidocaine, quinidine, propranolol, imipramine, and chlorpromazine. The monolithic silica column allowed highly hydrophobic basic drugs such as imipramine and chlorpromazine to be assayed; these are difficult to analyze by using a conventional particle-packed column. These drugs were clearly separated from acidic drugs naproxen and warfarin on the log k versus log P plots. The thermodynamic studies revealed that the retention of the drug was an enthalpy-driven process, and that the decrease in enthalpy for the phospholipid-modified ODS monolithic column was larger than those for immobilized artificial membrane columns. Our results suggest that the phospholipid-modified ODS monolithic column is applicable to affinity screening of drugs to phospholipids.     

Site‐specific deposition of Ag nanoparticles on ZnO nanorod arrays via galvanic reduction and their SERS applications

A controllable heterostructure consisting of ZnO nanorod arrays with attached Ag nanoparticles at only one end has been synthesized via a facile and convenient galvanic reduction method. Scanning electron microscopic images of these nanostructures showed good selectivity of Ag deposition on the tip of ZnO nanorod arrays. The formation of these regular Ag ZnO heterogeneous nanorod arrays can be explained by a localization of the electrons at the ends of the ZnO nanorods after the electron transfer step. By tuning the reaction time and the concentration of silver nitrate, the density of Ag nanoparticles on the tip of ZnO nanorods can be well controlled. Owing to the introduction of Ag nanoparticles with different densities, the resulting Ag ZnO heterogeneous nanorod arrays have been proved to be a versatile substrate for surface‐enhanced Raman scattering not only for common organic molecules but also for label‐free protein detection. Copyright © 2009 John Wiley & Sons, Ltd.     

Viscoelastic nanocomposite composed of titania nanosheets: multiple conductometric sensitivities

Graft polymerization of trimethoxysilyl-containing ammonium cations on negatively-charged titania nanosheets gives a photoluminescent viscoelastic nanocomposite. Proton conduction network comprised of adsorbed water molecules near the titania slabs leads to the multiple conductometric sensitivities to temperature, humidity, and photo-irradiation.     

Variable-precision dominance-based rough set approach and attribute reduction

In this paper, a variable-precision dominance-based rough set approach (VP-DRSA) is proposed together with several VP-DRSA-based approaches to attribute reduction. The properties of VP-DRSA are shown in comparison to previous dominance-based rough set approaches. An advantage of VP-DRSA over variable-consistency dominance-based rough set approach in decision rule induction is emphasized. Some relations among the VP-DRSA-based attribute reduction approaches are investigated.     

New Phase-Shifting Method Using Two Images

We propose a continuous two-step method (CTSM) to obtain an image from two interference images for the measurement time reduction of optical coherence tomography. Image processing is performed for each pixel in CTSM. The calculated signal intensity has an average and standard deviation after processing since the heterodyne beat signal contains the noise in the measurements. We assume that the heterodyne beat signal contains the random noise in simulations and calculate the influence of the normalized standard deviation (NSD = standard deviation/average) on the random noise intensity for both CTSM and the conventional three-step method (TSM). We found that the NSD of the CTSM is only 1.4 times greater than that of the TSM despite processing only two images.     

2-烷基TCNQ的红外光谱和结构研究——CH_2剪式振动的双峰与晶体场分裂的关系

测量了2-烷基TCNQ(C8TCNQ,C12TCNQ,C18TCNQ)浇铸膜的红外光谱,发现这类化合物的红外CH2剪式振动在1 471和1 462 cm-1处显示2个峰。这2个峰的强度比(I1 471/I1 462)随着烷基链的长度增加而明显减少。另外,来自CH2的1 471 cm-1吸收峰与来自TCNQ环的1 529 cm-1吸收峰的相对强度随着碳链的长度增加而不发生变化。CnTCNQ系列化合物的红外光谱CH2的剪式振动行为与长链脂肪酸中CH2行为很不相同。在长链脂肪酸中,晶体场效应导致了剪式振动分裂。考虑C12TCNQ的晶体结构,而将1 471cm-1峰归属为非叉指对接的碳链,将1 462 cm-1峰归于叉指对接的碳链,双峰的出现与晶体场分裂无关。并且得到烷基TCNQ中,非叉指对接的碳链的长度与碳链总长度无关的结论。