Chemotactic migration of leucocytes through corneal layers: an in vitro study

The ability of polymorphonuclear leucocytes (PMNs) to migrate into the different corneal layers in the presence or absence of a chemotactic stimulus was investigated in rabbits. The epithelial and/or endothelial surfaces were damaged in some corneas and in others they were intact. One side of the cornea was kept in contact with a viable population of rabbit PMNs and the other side with a chemotactic agent (zymosan activated human serum). The migration of PMNs into the cornea was traced histologically. The PMNs could not penetrate intact epithelium and Descemet's membrane even under the influence of a chemotactic stimulus. The stroma allowed PMN migration only when the chemotactic agent was present. The endothelium offered no resistance to PMN invasion whether the chemotactic stimulus was present or not.     

Milk Derived Antimicrobial Bioactive Peptides: A Review

In recent decades, bioactive peptides have attracted increasing interest as health promoting functional foods. A variety of naturally formed bioactive peptides have been found in fermented dairy products such as yogurt, sour milk, and cheese. Initially these peptides are inactive within the sequence of the parent protein molecule and can be generated by gastrointestinal digestion of milk, fermentation of milk with proteolytic starter cultures, and/or hydrolysis by proteolytic enzymes. Milk derived peptides exert a number of health beneficial activities, even upon oral administration. Bioactive peptides have a great impact on major body systems including the digestive, nervous, endocrine, cardiovascular, diabetes type II, obesity, and immune systems. Antimicrobial peptides are also an important ingredient of innate immunity, especially at mucosal surfaces such as lungs and small intestine that are constantly exposed to a range of potential pathogens. Therefore, it plays an important role in boosting natural immune protection by reducing the risk of chronic diseases. Bioactive peptides are considered as potent drugs with well-defined pharmacological residues and also used to formulate health-enhancing nutraceuticals.     

Nitric oxide-producing neurons remain intact after small bowel transplantation

This study documents the fate of nitric oxide neurons following small bowel transplantation. Heterotopic, syngeneic small bowel transplants were performed in five male Lewis rats. The grafts were harvested 7, 36, 55, 60, and 65 days postoperatively, together with the native bowel for comparison. NADPH diaphorase staining of cryostat sections was used to identify the nitric oxide-producing neurons. NADPH diaphorase activity was concentrated in the myenteric plexus, deep muscular, and submucous plexus. No differences were detected between the transplanted and native bowel at any time after transplantation. This suggests that nitric-oxide-producing neurons are well preserved after transplantation and that posttransplant dysmotility is probably not related to interrupted nitric oxide innervation.     

Effect of MgO in the microstructure formation of zirconia mullite composites from sillimanite and zircon

The effect of MgO additive on the structural, microstructural and hardness properties of zirconia mullite (MUZ) has been discussed. The MgO additive in MUZ not only stabilizes the cubic zirconia phase but also acts as a sintering aid for the formation of cross-linked mullite grains. The electron micrographs of plasma fused MgO–MUZ shows a uniform arrangement of platelet structure of mullite and dendrite structure of zirconia on mullite surface. The micrograph of plasma sintered composites shows a ladder like structure and a complete cross-linked mullite grains whereas the surface morphology of conventionally sintered composites clearly indicates the presence of small and big grains close packed to each other. Appreciable hardness and higher optical band gap have been observed for plasma fused MgO–MUZ composites. A complete dissociation of sillimanite and zircon has been occurred in plasma fused composites for the complete conversion of MUZ whereas the complete dissociation of sillimanite and zircon has not observed in plasma sintered and conventionally sintered composites. These observations have been realized from the X-ray diffraction and Fourier transform infrared studies.     

Synthesis, Characterization and Catalytic Properties of Mesoporous Cobalt Aluminophosphate Molecular Sieves

Isomorphously substituted cobalt(II) hexagonal mesoporous aluminophosphate (CoHMA) molecular sieves were synthesized hydrothermally and characterized by various analytical and spectroscopic techniques. It was deduced that cobalt ions exhibit a divalent oxidation state in tetrahedral coordination in mesoporous aluminophosphates. Further, unlike cobalt-containing microporous aluminophosphate molecular sieves, Co(II) ions remain in a tetrahedral geometry even after calcination. The catalytic activity of CoHMA was tested for the cyclohexane oxidation reaction under mild conditions. Remarkable substrate conversion and product (cyclohexanol) selectivity were obtained compared to several previously reported heterogeneous catalysts.     

Solubility of tri-iso-amyl phosphate in supercritical carbon dioxide and its application to selective extraction of uranium

The solubility of tri-iso-amyl phosphate (TiAP) in supercritical carbon dioxide (SCCO₂) was determined at 313–333 K with pressure ranging from 10 to 25 MPa. The solubility data of TiAP in SCCO₂ medium were correlated using four semi-empirical models. Selective extraction of uranium from simulated dissolver solution was demonstrated using SCCO₂ modified with TiAP. The extraction efficiency of uranium was found to be 95 ± 5%. The influence of temperature, pressure and acidity on the extraction of uranium was studied. An attempt was made to explain the plausible extraction mechanism.     

The Syntheses and Characterization of Interpenetrating Polymer Networks (IPNs) Derived from Cardanol-Based Dye and Linseed Oil-Based Polyurethanes

Interpenetrating Polymer Networks, from glycerol modified linseed oil polyurethanes and cardanol-based dyes, which are yet to be extensively studied were synthesized using benzoyl peroxide as initiator and ethylene glycol dimethacrylate as cross-linker. These polymers were characterized by Fourier transform infrared spectra, thermal analysis techniques such as thermogravimetric analysis, derivative thermogravimetry and differential thermal analysis. The kinetic parameters such as activation energy and orders of reaction were ascertained using Freeman-Carroll and Freeman-Anderson methods. The effects of changes in polyurethane to dye monomer weight ratio on the properties of such polymers were investigated at 1.2 and 1.6 NCO/OH ratios.