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The present study deals with the preparation of porous chitosan scaffolds by using a greener technique i.e., supercritical carbon dioxide (sc.CO2). 0.2 M chitosan (CS) solution in aqueous acetic acid was treated with 4% (w/v) genipin solution; the resulting hydrogels were subjected to solvent exchange prior to the final treatment procedures. Their morphology, pore structure, and physical properties were characterized by thermal analysis, X-ray diffractogram (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and the specific surface areas and porosimetry of scaffolds were determined by using N2 adsorption. The biological activity of scaffolds was investigated by immersing them into 1.5 x simulated body fluid (SBF) and cellular attachment study was assessed using Alamar Blue assay by seeding MG63 osteoblastic cells onto the scaffolds. The sc.CO2 assisted chitosan scaffold prepared by using green chemistry approach is highly pure and bioactive and can be served as a potential material for tissue engineering applications.

The ratio of fatty acids namely linoleic acid (LA, 18:2, n-6) and alpha linolenic acid (ALA, 18:3, n-3) in the diet plays an important role in enrichment of ALA in tissues and further conversion to long-chain polyunsaturated fatty acids (LC-PUFA) like eicosapentaenoic acid (EPA, 20:5, n-3) and docosahexaenoic acid (DHA, 22:6, n-3). Garden cress seed oil (GCO) is one of the richest sources of ω -3 fatty acid and contains 29–34.5% of ALA. In this study, dietary supplementation of GCO on bio-availability and metabolism of α -linolenic acid was investigated in growing rats. Male wistar rats were fed with semi-purified diets supplemented with 10.0% sunflower oil (SFO 10%); 2.5% GCO and 7.5% SFO (GCO 2.5%); 5% GCO and 5% SFO (GCO 5.0%); 10% GCO (GCO 10%) for a period of 8 weeks. There was no significant difference with regard to the food intake, body weight gain and organ weights of rats in different dietary groups. Rats fed with GCO showed significant increase in ALA levels in serum and tissues compared to SFO fed rats. Feeding rats with 10% GCO lowered hepatic cholesterol by 12.3% and serum triglycerides by 40.4% compared to SFO fed group. Very low density lipoprotein cholesterol (VLDL-C) and low density lipoprotein cholesterol (LDL-C) levels decreased by 9.45% in serum of 10% GCO fed rats, while HDL remained unchanged among GCO fed rats. Adipose tissue showed incorporation of 3.3–17.4% of ALA and correlated with incremental intake of ALA. Except in adipose tissue, the EPA, DHA levels increased significantly in serum, liver, heart and brain tissues in GCO fed rats. A maximum level of DHA was registered in brain (11.6%) and to lesser extent in serum and liver tissues. A significant decrease in LA and its metabolite arachidonic acid (AA) was observed in serum and liver tissue of rats fed on GCO. Significant improvement in n-6/n-3 fatty acid ratio was observed in GCO based diets compared to diet containing SFO. This is the first study to demonstrate that supplementation of GCO increases serum and liver ALA, EPA, DHA and decreases LA and AA in rats. Therefore, the GCO can be considered as a potential, alternate dietary source of ALA.

This report summarizes work in the two areas of zeolites and layered double hydroxides. Results of studies on structural aspects of Ru(bpy){sub 3}{sup 2+}-zeolite Y are summarized. Photoinduced electron transfer between entrapped Ru(bpy){sub 3}{sup 2+} and methylviologen (MV) in neighboring supercages was examined. Benzylviologen was also used. Since molecules larger than 13 {angstrom} cannot be accomodated in zeolite cages, the layered double metal hydroxides (LDH) LiAl{sub 2}(OH){sub 6}{sup +}X{sup {minus}} is being investigated. Organized assemblies of hydrophobic domains are made by introducing into the interlayer long-chain carboxylic acids R(CH{sub 2}){sub n}COOH. Zinc tetraphenylporphyrin sulfonate (ZnTPPS) is introduced into myristate-LiAl-LDH; photolysis of ZnTPPS-AiAl-LDH with MV{sup 2+} in solution was examined.

The intrinsic viscosity of protein solutions changes when denaturation occurs. Therefore, viscosity measurement using traditional glass capillary viscometers has been a key method to study the process of protein denaturation. Such measurements are laborious, time consuming and need at least 10 ml of sample. The Viscotek differential viscometer can be used as an on-line detector for high-performance liquid chromatography to monitor the viscosity of column effluent. In this study, samples were injected using an autosampler onto a “delay” column containing glass beads in place of the high-performance liquid chromatography columns. Results indicate guanidine hydrochloride, heat and pH act as denaturing agents and changes the intrinsic viscosities of serum albumin, turkey egg albumin, and ovalbumin solutions. The differential viscometer is sensitive and provides accurate measurements of minor changes in viscosities of very dilute protein solutions undergoing denaturation. The advantage of using the differential viscometer instead of conventional glass capillary viscometer is the increased sensitivity, precision, speed and operational ease that permits measurements of solution viscosity of low sample concentrations up to 1.2 μg of pure proteins.

This Paper describes the determination of acids and bases present in petroleum asphaltenes by differential non-aqueous potentiometric titrations. The acids and bases are split into differing pKa's by addition of model compounds. Structural information about the nature of the groups titrated was obtained from the study of many model systems. The strong, medium and weak acids titrated are due to the presence of carboxylic, phenolic and indolic functionality, respectively, whereas the strong bases titrated are due to pyridine groups, the medium strength bases due to pyrazines and sulphoxides and the very weak bases due to indoles and amides.