Preparation of Chitinous Compound/Gelatin Composite and Their Biological Application

Chitin, a natural abundant polysaccharide, have been investigated as prospected biochemical material due to its several biological advantages. It is insoluble in the most of the organic solvents due to its rigid crystalline structure. However, chitin regenerated hydrogel (RG) has been prepared by using the saturated calcium solvent system under mild conditions. And also, swelling hydrogel (SG) was prepared by using water. In this study, we prepared the suspension of chitinous hydrogel, and applied to fabricated the chitinous compound/gelatin composite sheets. Additionally, N-acetyl D-(+)-glucosamine was added into some composite sheets. We investigated the mechanical properties and growth of NIH/3T3 fibroblast cell for the prepared composite sheet.     

A coordinated approach towards the molecular weight determination of peptides by gel electrophoresis and fast-atom bombardment mass spectrometry

The molecular weight of peptides can be determined by fast-atom bombardment mass spectrometry (FAB-MS) following polyacrylamide gel electrophoresis (PAGE). Initial results combining the fast and efficient separation of peptides by PAGE and the unambiguous determination of molecular weights by FAB-MS have been demonstrated for the three peptides bradykinin, neurotensin and gramicidin S. This method has also been applied to the determination of the molecular weights of two fragments from the tryptic digest of horse-heart cytochrome c.     

Synthesis of Novel Carbosilane Dendrimers Based on Pentaerythritol

Novel pentaerythritol-based carbosilane dendrimers centered at carbon have been synthesised. Starting from tetraallyl ether based upon pentaerythritol as the core molecule, a succession of alternate Pt-catalyzed hydrosilylation of allyl groups with HSiC13 and allylations of SiC1 groups thus introduced with CH2=CHCH2MgBr in THF provided a divergent synthesis of three generations of carbosilane dendrimers in which the Si atoms are linked by CH2CH2CH2 groups. The reaction conditions for hydrosilylation must be well controlled. After purification by chromatography on silica gel pure products for each generation were obtained. The IR, ^1H and ^13C NMR spectra and elemental analysis data are consistent with the proposed structures. The molecular weights of the resulting carbosilne dendrimers have been determined by vapor pressure osmometry.     

Intramolecular Anodic Olefin Coupling Reactions and the Use of Electron-Rich Aryl Rings(1)

The utility of intramolecular anodic olefin coupling reactions involving electron-rich aromatic rings for constructing fused, bicyclic ring skeletons has been examined. Reactions involving alkoxy-substituted phenyl rings were found to benefit strongly from a 3-methoxy substituent on the phenyl ring. Although overoxidation of the bicyclic product was observed in these reactions, this problem could be minimized with the use of controlled potential electrolysis conditions when a monomethoxy phenyl ring was used and avoided entirely with the use of a vinyl sulfide moiety as the initiator when a more electron-rich phenyl ring was used. Reactions involving 4-alkoxy-substituted phenyl rings as substrates did not lead to good yields of fused products. Furan rings were found to be excellent coupling partners for the reactions and afforded products having fused, bicyclic furan ring skeletons. Cyclizations involving furans were shown to be compatible with the formation of both six- and seven-membered rings, the generation of a quaternary carbon, and the use of a variety of electron-rich olefins as the other coupling partner. It appears that the furan can serve as either the initiating group or the terminating group for the cyclizations. Finally, the reactions were shown to be compatible with the use of a pyrrole ring as one of the participants.     

BF_3·OEt_2 Promoted Solvent-free Synthesis of Benzimidazole Derivatives

Differently substituted benzimidazoles have been synthesized in very good yields in solvent-free conditions from o-phenylenediamine and aldehydes in the presence of BF3·OEt2 as a catalyst. The method is applicable to aromatic, unsaturated and aliphatic aldehydes and to substituted o-phenylenediamines without significant differences.     

Synthesis, Crystal Structure and Characterization of α-（1-Benzimidazolyl） -hypnone Cobalt（Ⅱ） Complex： [CoCl （ C7H5N2CH2COPh）4] Br

The crystal structure of [CoCl ( C7H5N2CH2COPh)4] Br has been determined by means of X-ray crystallography. The molecular structure consists of a discrete [CoCl ( C7H5N2CH2COPh)4] ^ cation and one Br^- anion, in the [CoCl ( C7H5N2CH2COPh)4]^ cation, the coordination geometry of the central Co atom is square-pyramidal with four tertiary N atoms of benzimidazole from four α-( benzimidazol-1-yl) -hypnone ligands in the basal position and one chloride anion in the apical position. In the solid state, [CoCl ( C7H5N2CH2COPh)4]^ and Br^- anion possess intermolecular and intramolecular interactions, which stabilize the crystal structure. The characterization of the title compound were also carried out by using elemeutal analysis, FTIR, UV spectrometries and TG-DSC.     

Preparation of reissert compounds derived from the thieno[3,2-c]pyridine,thieno[2,3-d]pyridazine and the thieno[2,3-d]pyrimidine ring systems

The use of tributyltin cyanide, trimethylsilyl cyanide and potassium cyanide in the Reissert reaction is contrasted in the furo[3,2-c]pyridine, thieno[3,2-c]pyridine, thieno[2,3-dpyridazine, and thieno[2,3-d]pyrimidine ring systems.     

Matching Batch Sizes to Machine Shop Capabilities: An Example in Production Scheduling

A totally new approach to the setting of batch quantities and production lead times is described in which both are set together in relation to the work-load on the shop. The method is practical computationally and has application in many companies faced with a "repeat-order" situation. Simulation studies of a 75-machine job-shop are described in which use of the decision rules developed showed considerable improvement over the existing practice. The system is particularly applicable in situations where it is not feasible to use work-sequencing systems on individual machine groups, since it works by the control of inlet times only. Although the heuristic developed was tested using simulation methods all data are realistic and relate to the particular shop for which it was designed.     

Lacke, Anstrichstoffe

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