Diffractive micro bar codes for encoding of biomolecules in multiplexed assays

Microparticles incorporating micrometer-sized diffractive bar codes have been modified with oligonucleotides and immunoglobulin Gs to enable DNA hybridization and immunoassays. The bar codes are manufactured using photolithography of a chemically functional commercial epoxy photoresist (SU-8). When attached by suitable linkers, immobilized probe molecules exhibit high affinity for analytes and fast reaction kinetics, allowing detection of single nucleotide differences in DNA sequences and multiplexed immunoassays in <45 min. Analysis of raw data from assays carried out on the diffractive microparticles indicates that the reproducibility and sensitivity approach those of commercial encoding platforms. Micrometer-sized particles, imprinted with several superimposed diffraction gratings, can encode many million unique codes. The high encoding capacity of this technology along with the applicability of the manufactured bar codes to multiplexed assays will allow accurate measurement of a wide variety of molecular interactions, leading to new opportunities in diverse areas of biotechnology such as genomics, proteomics, high-throughput screening, and medical diagnostics.     

Sorbitol Hydrogenolysis Over Ni, Pt and Ru Supported on NaY

The hydrogenolysis of sorbitol into 1,2-propanediol (PD), ethylene glycol (EG) and glycerol (G) was investigated over Ni, Pt and Ru supported on NaY at 220 °C and 60 bar in a batch reactor. Ni(6 %)–NaY was investigated in detail at different process conditions, including its recyclability. Attempts have been made to rationalize the experimentally observed conversion and product selectivity obtained over the different catalysts with results of Density Functional Theory calculations of adsorption energy and bond length changes in sorbitol adsorbed over various planes of Ni, Pt and Ru.     

Investigation of liquid diffusion into contact lenses using an electron spin resonance technique

In this study, electron spin resonance (ESR) spectroscopy was used for the first time to investigate liquid diffusion into contact lenses. As contact lenses are not paramagnetic substances, they were labeled with nitroxide spin probes to get an ESR spectrum. Thus, it gives a solid spin‐labeled ESR spectrum. The shape and intensity of the ESR signals depend on the environment of these spin probes. The spin probe environment began to change from solid to liquid if liquid were dropped into the system. Consequently the ESR spectra began to change with time, too. By following these changes, three distinct steps were found. Their diffusion coefficients were determined to be 6.38 × 10^?8 cm²/s for the first step (rapid decay region) and 0.37 × 10^?8 cm²/s for the second step (slow decay region), and 2.50 × 10^?8 cm²/s for the third and last step (desorption region). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2942–2946, 2006     

Effect of extra polymeric substance removal on sludge reduction potential of Bacillus licheniformis at its optimised pH condition

The effect of extracellular polymeric substances (EPSs) on the solubilisation of municipal wastewater sludge by protease‐secreting bacteria was investigated. The untreated sludge is an environmental menace, so sludge management techniques are introduced to treat and dispose sludge in a proper way. Sludge pretreatment is needed to increase the solubilisation and the efficiency of treatment methods. The present study deals with sludge solubilisation by bacterial enzymatic pretreatment. The EPS present in the sludge was removed by sodium hydroxide and formaldehyde to enhance solubilisation and increase the bacterial enzymatic activity. After the removal of EPS with different normalities of NaOH, there was about 11–18% sludge solubilisation and about 8–16% sludge reduction during bacterial pretreatment. Bacterial enzymatic pretreated sludge was further treated using aerobic digesters. From the results obtained in aerobic digestion, 0.06 N NaOH was chosen as the optimal concentration to remove EPSs.     

5 V, DC-12 GHz InP/InGaAs HBT amplifier

An InP/InGaAs HBT cascode amplifier operating from a single 5 V power supply is described. The circuit has a DC gain of 17.2 dB and a -3 dB frequency point of 12.3 GHz. This results in a gain-bandwidth product in excess of 90 GHz. The frequency response of the amplifier remains constant if the power supply voltage is as low as 4 V.<>     

Investigations on polyurethane ionomers. II. 3,4-dihydroxycinnamic acid-based anionomers

Polyurethanes of different compositions were synthesized by chain extending the prepolymer formed by the reaction of various polyols and diisocyanate with 3,4-dihydroxycinnamic acid. The polyurethanes were converted to their anionomers by treating with metal acetates. The polyurethanes were characterized using FTIR, FTNMR, TGA, and DSC analysis. The molecular weights of the polymers were determined using GPC. A detailed study of the effect of variation of molecular weight of the polyols and mol ratio of the various reactants on the glass transition temperature and molecular weight of the polyurethanes was made. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2105–2109, 1997     

Angiotensin II stimulates expression of transcription factors c-Jun and c-Fos in cyclosporine induced human gingival fibroblasts

The present study demonstrates that the expression of c-Jun and c-Fos are elevated in gingival fibroblast cells treated with angiotensin II and cyclosporine. The healthy human gingival tissues were collected and gingival fibroblasts were isolated and cultured. We used RT-PCR and Western blot analysis to identify the expression of c-Jun and c-Fos in cyclosporine and angiotensin II treated human gingival fibroblast cells. We found that angiotensin II in combination with cyclosporine induces c-Jun and c-Fos expressions significantly; however, the angiotensin II antagonist losartan inhibits the expression of c-Jun and c-Fos (p < 0.01). The data suggest that angiotensin II in combination with cyclosporine modulates the expression of c-Jun and c-Fos in human gingival fibroblast cells.     

Phenolic Characterization and Geographical Classification of Commercial Extra Virgin Olive Oils Produced in Turkey

The aim of this research was to characterize the extra virgin olive oil samples from different locations in the Aegean coastal area of Turkey in terms of their phenolic compositions for two consecutive years to show the classification of oil samples with respect to harvest year and geography. Forty seven commercial olive oil samples were analyzed with HPLC–DAD, and 17 phenolic compounds were quantified. Hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, ferulic acid, cinnamic acid, luteolin and apigenin were the characteristic phenols observed in all oil samples for two harvest years. Syringic acid, vanillin and m-coumaric acid were the phenolic compounds appeared in the olive oil depending on the harvest year. Partial least square-discriminant analysis (PLS-DA) of data revealed that oils from the north Aegean and south Aegean areas had different phenolic profiles. The phenolic compounds, which played significant roles in the discrimination of the olive oils, were tyrosol, oleuropein aglycon, cinnamic acid, apigenin and hydroxytyrosol to tyrosol ratio. The Aegean coastal region is the largest olive oil producer and exporter of Turkey. This study shows that the olive oils from different parts of the region have their own defining characteristics that can be used in the authentication studies and geographical labeling of Turkish olive oils.