Biogenic amines formation in seer fish (Scomberomorus commerson) steaks packed with O2 scavenger during chilled storage

A comparative study of the effect of O₂ scavenger on the formation of biogenic amines during chilled storage of seer fish (Scomberomorus commerson) was carried out. O₂ scavenger was effective in reducing the O₂ content of the pack up to 99.95% within 24 h and it extended shelf-life up to 20 days compared to only 12 days for air packs. The biogenic amine content increased significantly (P < 0.05) in air packs compared to O₂ scavenger packs. Histamine, putrescine and cadaverine reached maximum levels of 6.8, 14.6 and 14.7 μg/g, respectively, in air packed samples at the end of 15th day. Spermidine and spermine levels increased slightly and did not change much throughout the storage period. Agmatine was absent in the O₂ scavenger packs throughout the storage period, whereas tyramine was observed only towards the end of storage study.     

Monolayers of triaroylbenzene derivatives

Monolayers of triaroylbenzene derivatives bearing three octyl groups projecting away from the molecular core and terminated by hydroxyl, carboxylic acid, and methyl ester groups have been studied using surface pressure isotherm measurements and Brewster angle microscopy. The octyl derivative lacking a terminal hydrophilic group forms a monolayer of limited stability. The derivatives with hydrophilic end-groups on the octyl chains form stable monolayers. A reorientation at the water surface under compression from a ‘face-on’ to a distorted ‘edge-on’ arrangement appears likely. At intermediate molecular areas, a phase transition occurs and aggregate formation is observed. Studies of mixtures with methyl stearate exhibit a contrast inversion between the background phase and immiscible domains of methyl stearate supporting the concept of a reorientation of the triaroylbenzene derivatives during compression.     

Enzymatic synthesis of banana flavour (isoamyl acetate) by Bacillus licheniformis S-86 esterase

New carboxylesterase from organic-solvent-tolerant Bacillus licheniformis S-86 strain was characterized. The enzyme named as type II esterase showed an optimal activity in the temperature range 60–65 °C and pH 8.0. The enzyme was moderatly thermostable (half-life of 1 h at 50 °C), but remarkable stable at extremely alkaline pH, retaining 100% of its activity at pH 10.0–11.0. Furthermore, the esterase showed high stability in detergents (86% residual activity in 10% SDS), and also 0.1% ionic and non-ionic detergents are inducers of enzyme activity. PMSF, a serine protease inhibitor, did not show any effect on the activity. The immobilized type II esterase was able to synthesize isoamyl acetate from isoamyl alcohol and p-nitrophenyl acetate (acyl donor) in n-hexane. The resulting ester yield (42.8%), obtained at a low temperature (28 °C) and with a very low amount of enzyme (4.6 × 10^?5 mg ml^?1), indicates a high potential for type II esterase in isoamyl acetate synthesis for production purposes.     

Studies on photoconductivity, photovoltaic effect and photoluminescence in chemically deposited (Cd0.95–Pb0.05)S:CdCl2,Dy/Y films

Results of photoconductivity (PC) and photoluminescence (PL) are presented for films of (Cd_0.95–Pb_0.05)S:CdCl₂,Dy/Y prepared at 60 °C and RT on glass substrates. PC is found to be enhanced in films prepared at 60 °C particularly in presence of impurities. PL is found to be stronger in films prepared at RT. While films prepared in presence of Dy show one peak in green yellow region, those prepared in presence of Y show two peaks one in blue and other in green yellow regions. Results of SEM, XRD, and optical absorption spectra, which have been used to characterize the materials, are presented. Photovoltaic efficiency in (Cd_0.95–Pb_0.05)S:CdCl₂,Dy films has been found to be ∼5%.     

Design of Wide-Band Microstrip Antenna Array at Millimeter Wave Frequencies

This paper describes the Design of Broadside 8-Elements Microstrip Antenna Array at Ka-Band using corporate feed. Array is designed for the Broadband applications for 32 GHz to 36 GHz (4 GHz Bandwidth). The Gain of the Antenna Array is 18 dBi and the 3-dB Beamwidth in E - & H - Plane is 18 degree and 27 degree respectively with minimum sidelobe level of 15 dBc. Antenna test results show a close agreement between the designed and measured values. The Antenna Array has been printed on 10 mil RT-Duriod (ε_r = 2.22) substrate.     

Quantitative assessment of post-LASIK corneal infiltration with frequency domain anterior segment OCT: A case report

We present the use of frequency domain (FD) optical coherence tomography (OCT) for quantitative assessment of the infiltration in the eye with post-laser in situ keratomileusis (LASIK) corneal inflammation. Serial OCT images are taken in a patient with post-LASIK inflammation and are used to see the response to treatment over a time period. Clinical value of FD-OCT as a diagnostic tool in objective assessment of corneal inflammation and response to treatment is shown.     

Electrochemical impedance-based DNA sensor using a modified single walled carbon nanotube electrode

Carbon nanotubes have become promising functional materials for the development of advanced electrochemical biosensors with novel features which could promote electron-transfer with various redox active biomolecules. This paper presents the detection of Salmonella enterica serovar Typhimurium using chemically modified single walled carbon nanotubes (SWNTs) with single stranded DNA (ssDNA) on a polished glassy carbon electrode. Hybridization with the corresponding complementary ssDNA has shown a shift in the impedance studies due to a higher charge transfer in ssDNA. The developed biosensor has revealed an excellent specificity for the appropriate targeted DNA strand. The methodologies to prepare and functionalize the electrode could be adopted in the development of DNA hybridization biosensor.     

Activity of Ferric Oxide in Steelmaking Slag

Refining reactions in steelmaking primarily involve oxidation of impurity element(s). The oxidation potential of the slag and the activity of oxygen in the metal (h_O) are the major factors controlling these chemical reactions. In turn, the oxidation potential of the slag is influenced strongly by the equilibrium distribution of oxygen between ferrous and ferric oxides. We recently investigated the activity coefficient of FeO in steelmaking slag and the effect of chemical composition thereon. This work is focused on estimation of the activity coefficient of Fe₂O₃.     

An 80-Tile Sub-100-W TeraFLOPS Processor in 65-nm CMOS

This paper describes an integrated network-on-chip architecture containing 80 tiles arranged as an 8x10 2-D array of floating-point cores and packet-switched routers, both designed to operate at 4 GHz. Each tile has two pipelined single-precision floating-point multiply accumulators (FPMAC) which feature a single-cycle accumulation loop for high throughput. The on-chip 2-D mesh network provides a bisection bandwidth of 2 Terabits/s. The 15-FO4 design employs mesochronous clocking, fine-grained clock gating, dynamic sleep transistors, and body-bias techniques. In a 65-nm eight-metal CMOS process, the 275 mm² custom design contains 100 M transistors. The fully functional first silicon achieves over 1.0 TFLOPS of performance on a range of benchmarks while dissipating 97 W at 4.27 GHz and 1.07 V supply.     

Study on growth of hollow nanoparticles of alumina

This article addresses the growth of hollow nanocrystalline particles of γ-alumina by the post-oxidation of nano-aluminium particles in air. The nanoparticles of aluminium were synthesized in a DC-transferred arc thermal plasma reactor. The as-synthesized nano-aluminium particles were oxidized, in air, at different temperatures. The as-synthesized parent nano aluminium and their daughter nanoparticles of aluminium oxide were thoroughly characterized with the help of X-ray diffraction analysis, high resolution transmission electron microscopy and thermogravimetric analysis. Two-step oxidation behaviours, unique in nanoparticles, are found to be the main driving force behind the formation of hollow spherical structures. The entire phenomenon is compared with the oxidation behaviour of coarse grain aluminium. The content of γ-alumina, identified by X-ray diffraction, relative to that of unreacted aluminium, has increased almost exponentially with the oxidation temperature in the case of nano aluminium. Similar behaviour is not observed in the case of coarse grain aluminium. The crystalline features of alumina, forming the walls of the hollow sphere, were confirmed by high resolution transmission electron microscopy.