Scanning LLL x-ray interferometry

A new formalism is presented for the theory of scanning LLL x-ray interferometry, which takes account also of the amount of x-ray absorption and of crystal yawing. It is based on the Takagi approach to the dynamical theory of x-ray diffraction and uses, to a great extent, the formalism of quantum mechanics, in order to reduce the algebraic complexity of the Ewald-von Laue approach. The formalism presented here is an easy-to-handle tool for the study of x-ray propagation in multicrystal systems and for the investigation into deviations of the travelling-fringe period from the spacing of diffracting planes, as it explains how interference features change when moving in paramater space.     

Living anionic polymerization of N‐methoxymethyl‐N‐isopropylacrylamide: Synthesis of well‐defined poly(N‐isopropylacrylamide) having various stereoregularity

Anionic polymerization of N‐methoxymethyl‐N‐isopropylacrylamide ( 1 ) was carried out with 1,1‐diphenyl‐3‐methylpentyllithium and diphenylmethyllithium, ‐potassium, and ‐cesium in THF at ?78 °C for 2 h in the presence of Et₂Zn. The poly( 1 )s were quantitatively obtained and possessed the predicted molecular weights based on the feed molar ratios between monomer to initiators and narrow molecular weight distributions (M_w/M_n = 1.1). The living character of propagating carbanion of poly( 1 ) either at 0 or ?78 °C was confirmed by the quantitative efficiency of the sequential block copolymerization using N,N‐diethylacrylamide as a second monomer. The methoxymethyl group of the resulting poly( 1 ) was completely removed to give a well‐defined poly(N‐isopropylacrylamide), poly(NIPAM), via the acidic hydrolysis. The racemo diad contents in the poly(NIPAM)s could be widely changed from 15 to 83% by choosing the initiator systems for 1 . The poly(NIPAM)s obtained with Li⁺/Et₂Zn initiator system possessed syndiotactic‐rich configurations (r = 75–83%), while either atactic (r = 50%) or isotactic poly(NIPAM) (r = 15–22%) was generated with K⁺/Et₂Zn or Li⁺/LiCl initiator system, respectively. Atactic and syndiotactic poly(NIPAM)s (42 < r < 83%) were water‐soluble, whereas isotactic‐rich one (r < 31%) was insoluble in water. The cloud points of the aqueous solution of poly(NIPAM)s increased from 32 to 37 °C with the r‐contents. These indicated the significant effect of stereoregularity of the poly(NIPAM) on the water‐solubility and the cloud point in water © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4832–4845, 2006     

Asymmetric interaction of optically active polymers with asymmetric small molecules. IV. Effect of hydrophobic groups on asymmetric interaction

In order to investigate the mechanism of the asymmetric interaction between optically active polymers and small molecules, optically active copolymers of N-acrylyl L-amino acids(N-acrylyl-L -phenylalanine, N-acrylyl-L -tryptophan, and N-acrylyl-L -leucine, respectively) and N,N′-hexamethylene diacrylylamide were synthesized, and interaction of these polymers with the optical isomers of phenylalanine and tryptophan was investigated. In the interaction of these acidic polymers with amino acids performed at pH 5.0, significant difference in amount of adsorption between the D and L isomers of amino acids were observed, and the L form of amino acids was adsorbed preferentially. The interaction between optically active small molecules was also investigated: these results showed a similarity to the results for interaction between optically active polymers and amino acids. In some instances of asymmetric interaction the influence of hydrophobic interaction between a polymer and substrate was clearly perceived. The stereoselective effects on the asymmetric interaction are discussed.     

Synthesis of photoreactive polyimide having indan structure

Polyimide containing an indan unit and alkyl moiety with a high molecular weight was prepared from 5,7‐diamino‐1,1,4,6‐tetramethylindan and 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride. This polyimide was amorphous and soluble in common organic solvents, such as tetrahydrofuran, chloroform, and cyclopentanone. Thermogravimetry of the polyimide showed good thermal stability, indicating that a 10% weight loss of the polyimide was observed at 500 °C in nitrogen. The glass‐transition temperature of the polyimide was not observed by DSC measurement between room temperature and 400 °C at a heating rate of 10 °C/min (Apparatus: DSC3100 MAC Science Co., Ltd.). Transparency of the polyimide at 365 nm was 80%. The polyimide acted as a photosensitive resist of negative type by UV radiation. The resist had a sensitivity of 31 mJ/cm² and a contrast of 2.3 when it was developed with cyclopentanone at room temperature. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 423–428, 2002     

Specific interaction between polyethylenimine and azo dyes carrying hydroxyl groups

The binding of acid azo dyes having phenolic hydroxyl groups such as orange I ( I ), orange II ( II ), chrome violet ( III ), 4-hydroxyazobenzene-4′-sulfonate ( IV ), and 2,4-dihydroxyazobenzene-4′-sulfonate ( V ) by polyethylenimine was studied by equilibrium dialysis and spectroscopic methods. The results obtained indicate that dyes ( III ) and ( V ) with two OH groups are bound much more strongly than dyes ( I ), ( II ), and ( IV ) with one OH group. Also polyethylenimine is far superior to any other polymers which have been examined, including bovine serum albumin, polyvinylpyrrolidone, and poly-L -lysine, in its ability to form complexes with these dyes ( III ) and ( V ). The OH groups involved participate preferentially in complex formation with polyethylenimine. The unusual affinity of polyethylenimine for the dyes carrying OH groups is discussed.     

Synthesis and properties of 1,3,5-benzene periodic mesoporous organosilica (PMO): novel aromatic PMO with three point attachments and unique thermal transformations

A new aromatic periodic mesoporous organosilica material containing benzene functional groups that are symmetrically integrated with three silicon atoms in an organosilica mesoporous framework is reported. The material has a high surface area, well-ordered mesoporous structure and thermally stable framework aromatic groups. The functional aromatic moieties were observed to undergo sequential thermal transformation from a three to two and then to a one point attachment within the framework upon continuous thermolysis under air before eventually being converted to periodic mesoporous silica devoid of aromatic groups at high temperatures and longer pyrolysis times. The mesoporosity of the material was characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and nitrogen porosimetry, whereas the presence and transformation of the aromatic groups in the walls of the materials were characterized by solid-state NMR spectroscopy, mass spectrometry, and thermogravimetric analysis. The attachment of a benzene ring symmetrically onto three siloxanes of the framework was used advantageously as a cross-linker to enhance the thermal stability of the organic group. Some of these properties are investigated in comparison with other aromatic PMOs that have only two point attachments and an amorphous phenylsilica gel that has only one point attachment. The successful synthesis of the first aromatic PMO with its organic group attached within the framework through more than two points is an important step toward the synthesis of PMOs having organic groups with more complex and multiple attachments within the framework.     

Binding of metal ions by polyethylenimine and its derivatives

Measurements have been made of the binding of divalent metal ions, Cu²⁺, Ni²⁺, Co²⁺, and Zn²⁺ ions, by polyethylenimine (PEI) and its acetyl or alkyl derivatives by the equilibriumdialysis technique. These metal ions, in particular the Cu²⁺ ion, exhibited tremendously remarkable binding affinity toward PEI. The extent of complexation of the polymer with the metal ions was decreased markedly by acetylation or alkylation of the polymer. PEI with no primary amine showed an appreciable decrease in its affinity for the metal ion. These results indicate the participation of the primary amine of the polymer in the formation of the complex. A cooperative binding isotherm was observed in PEI–metal ion complex formation, suggesting swelling or conformational change of the polymer induced by this coordination process. Binding of the Cu²⁺ ion by PEI was found to be essentially independent of temperature over the range 5–35°C.     

Thermal stability of phthalate esters: Effect of substituents on the β-carbon atom

In order to clarify the mechanism conferring heat resistance on phthalate esters, those with a substituent on the β-carbon atom, such as bis(2-aminobutyl) phthalate, bis(2-nitrobutyl) phthalate, bis(2,4-diphenylbutyl) phthalate and dineopentyl phthalate, were synthesized and their thermal stabilities were studied by thermogravimetry and differential thermal analysis. The analytical results for these phthalate esters were compared with those for dibutyl phthalate, with a straight alkyl chain. As the temperatures required for a 3% weight loss of phthalate esters with a substituent, an electron-donating group (amino group) or an electron-accepting group (nitro group) on the β-carbon atom move to the higher end of the range, the effect of the adjacent group was recognized. The presence of a phenyl group in phthalate esters considerably improved the heat resistance. It is considered that the high heat resistance of bis(2,4-diphenylbutyl) phthalate is due to the obstruction of the planar configuration for cis elimination by the phenyl group and hindrance by the phenyl group of the formation of the six-membered cyclic transition state owing to the interaction between non-bondable molecules.     

Immunoaffinity isolation of CEACAM1 on hydrazide-derivatized cellulose with immobilized monoclonal anti-CEA antibody

Carcinoembryonic cell adhesion molecule 1 (CEACAM1) is a human membrane glycoprotein belonging to the carcinoembryonic antigen (CEA) family and to the immunoglobulin superfamily. It is expressed in apical membranes of many epithelial cells in gastrointestinal and urogenital tract and also in granulocytes and lymphocytes, and its biological effect in human tissues has recently been discussed in literature. The purpose of this study was to isolate CEACAM1 glycoprotein from bile and characterize its purity and recovery which has not been described before. Affinity chromatography of CEACAM1 on hydrazide-activated cellulose with immobilized monoclonal anti-CEA F34-187 antibody is described. The immunoglobulin carbohydrate moiety was oxidized by periodate and then bound to hydrazide-activated matrix. Crude protein fraction from bile was applied on the affinity column and after extensive washing of non-bound proteins CEACAM1 was eluted with 6 M guanidine-HCl. A single immunopositive 85 kDa band was detected on Western blots with anti-CEA antibody after SDS-PAGE. We found out that CEACAM1 was not stainable with any common method of protein staining and the only non-specific method which could detect the 85 kDa band was a lectin staining.