Poly(n-butyl methacrylate) with primary amine end groups for supporting cell adhesion and proliferation of renal epithelial cells

Polymer coatings that support epithelial cell culture have been developed. Ozonolysis and subsequent workup of poly(butyl methacrylate-co-butadiene) copolymers is used to form oligomers with carboxylic acid end groups, which are then further reacted with diamines to provide poly(butyl methacrylate)s with primary amine end groups. The polymers are cast as films and used as cell culture substrates for human dermal fibroblasts and human renal epithelial cells. Fibroblast and epithelial cells adhere and proliferate on acid functional materials but on amine functional films epithelial cells show greater viability than fibroblasts.     

Effect of Enzymatic Hydrolysis on the Antioxidant Activity of Red and Green Seaweeds and Characterization of the Active Extracts

In the present study, the effect of enzymatic hydrolysis on the antioxidant activity of three red seaweeds (Chondria cornuta, Chondria dasyphylla, and Murrayella periclados) and two green seaweeds (Cladophora sp. and Ulva lactuca) from the Kuwait coast were evaluated. The seaweeds were hydrolyzed with five carbohydrases and three proteases, and the resulting extracts were tested for antioxidant activity. The total phenolic content and yield of the extracts varied greatly depending upon the species and enzyme used for hydrolysis. Of the 40 enzymatic extracts screened for antioxidant activity, the Viscozyme and Alcalase extracts of M. periclados, Neutrase and Ultraflo extracts of Cladophora sp., and Neutrase extracts of C. cornuta had high antioxidant activity compared to other enzymatic extracts in various in vitro assays. Fractionation of the extracts revealed that the radical scavenging and reducing power of the extracts were mainly due to phenolic fractions. In contrast, the iron-chelating ability was mainly due to protein fractions. The level of prevention of lipid oxidation in the liposome model system varied for different fractions of extracts and did not correlate with total phenolic content and other antioxidant properties. The results of the study show that, by hydrolyzing seaweeds with specific enzymes, customized seaweed extracts with specific bioactivity could be obtained.     

High-performance liquid chromatographic determination of furosemide in plasma and urine and its use in bioavailability studies

Steroid hydroxylase cytochrome P450c17 has been previously purified from microsomal fractions of immature rat livers. In this study, we investigated the expression of P450c17 in rat livers to understand a role of steroidogenesis in the extrasteroidogenic tissue. Upon immunoblot analysis utilizing liver microsomes from rats, P450c17 was detected in 1 and 3 week old rats but not in adult rats. Data from immunohistochemical studies also showed a similar age-dependent expression of P450c17 and indicated that P450c17 detected in immature rat livers is localized in cells surrounding interlobular veins. This age-dependent expression of P450c17 in rat livers was observed in both sexes. Upon enzymatic analysis utilizing microsomal fractions from livers, levels of 17alpha-hydroxylase and 17,20-lyase activity for pregnenolone and progesterone increased by 3 weeks and dramatically reduced at 7 weeks, which is consistent with the expression level of P450c17. These data clearly indicate that P450c17 is expressed in immature rat liver to produce 17alpha-hydroxysteroids and C19-steroids. Based upon immunoblot analysis, the expression level of P450c17 in immature rat livers was approximately one third of that in testis. Compared expression level of P450c17 and total volume of organs between liver and testis, the total amount of steroid metabolites produced by liver P450c17 could be greater than that produced by gonadal P450c17. Because of the absence of P450c17 in rat adrenal glands, rat liver could be the major site for producing 17alpha-hydroxysteroids and C19-steroids in this particular period of life. Although physiological products formed by P450c17 in liver and their roles remain to be elucidated, this study suggests a large capacity of prepubertal rat liver for participating the production of steroid hormones and a putative importance of 17alpha-hydroxysteroids and C19-steroids, such as cortisol and androstendione, which are generally believed to be minor components of steroid hormones in rodents.     

A Defect Tolerance Scheme for Nanotechnology Circuits

Lithography-based integrated circuit fabrication is rapidly approaching its limit in terms of feature size. The current alternative is nanotechnology-based fabrication, which relies on self-assembly of nanotubes or nanowires. Such a process is subject to a high defect rate, which can be tolerated using carefully crafted defect tolerance techniques. This paper presents an algorithm for reconfiguration-based defect tolerance in nanotechnology switches. The algorithm offers an average switch density improvement of 50% to 100% to most recently published techniques. The algorithm is also consistent in improving the yield through minimizing false rejects as the results show over a large sample. The improvement percentage varies depending on the manufactured switch size and the desired defect-free size with the improvement in efficiency directly proportional to the size of the switch.     

Test Set Compression Through Alternation Between Deterministic and Pseudorandom Test Patterns

This paper presents a new reseeding technique that reduces the storage required for the seeds as well as the test application time by alternating between ATPG and reseeding to optimize the seed selection. The technique avoids loading a new seed into the PRPG whenever the PRPG can be placed in a state that generates test patterns without explicitly loading a seed. The ATPG process is tuned to target only undetected faults as the PRPG goes through its natural sequence which is maximally used to generate useful test patterns. The test application procedure is slightly modified to enable higher flexibility and more reduction in tester storage and test time. The results of applying the technique show up to 90% reduction in tester storage and 80% reduction in test time compared to classic reseeding. They also show 70% improvement in defect coverage when the technique is emulated on test chips with real defects.