Antimicrobial susceptibility and coagulase gene typing of Staphylococcus aureus isolated from bovine clinical mastitis cases in Turkey

The objectives of this study were to determine antimicrobial resistance patterns of Staphylococcus aureus strains isolated from bovine clinical mastitis cases and to subtype the strains by polymerase chain reaction (PCR) technique based on coagulase gene polymorphism. Two hundred sixty-five S. aureus isolates collected from individual animals in different herds (n = 235) from 1995 to 2004 were tested for susceptibility to penicillin, ampicillin, amoxicillin-clavulanate, oxacillin, oxytetracycline, enrofloxacin, kanamycin-cephalexin, and trimethoprim-sulfamethoxazole using the agar disc diffusion test. Strains were also tested for β-lactamase production. A total of 29.8% of the strains were susceptible to all antimicrobial agents tested. The highest resistance was observed in 63.3% of the strains against β-lactam antibiotics, penicillin and ampicillin. Oxytetracycline resistance was observed in 27.9% of the strains, either alone or in combination with β-lactams. No resistance was detected for amoxicillin-clavulanate, oxacillin, enrofloxacin and kanamycin-cephalexin. β-Lactamase production and resistance to β-lactam antibiotics were usually correlated. Resistance against β-lactams increased from 43.5% in 1995 to 58 to 77% from 1999 to 2004.One hundred twenty-five strains were examined for coagulase gene polymorphism. The isolates were subtyped into 4 types by coagulase gene-based PCR. A predominant 1000-bp PCR product was observed in 60.8% of the isolates typed. The results indicate that a few coagulase gene types of S. aureus are responsible for the majority of bovine clinical mastitis cases in one province of Central Anatolia region, Turkey.     

New large volume hydrothermal reaction cell for studying chemical processes under supercritical hydrothermal conditions using time-resolved in situ neutron diffraction

The design and testing of a new large volume Inconel pressure cell for the in situ study of supercritical hydrothermal syntheses using time-resolved neutron diffraction is introduced for the first time. The commissioning of this new cell is demonstrated by the measurement of the time-of-flight neutron diffraction pattern for TiO(2) (Anatase) in supercritical D(2)O on the POLARIS diffractometer at the United Kingdom's pulsed spallation neutron source, ISIS, Rutherford Appleton Laboratory. The sample can be studied over a wide range of temperatures (25-450 °C) and pressures (1-355 bar). This novel apparatus will now enable us to study the kinetics and mechanisms of chemical syntheses under extreme environments such as supercritical water, and in particular to study the crystallization of a variety of technologically important inorganic materials.     

Highly efficient pure white phosphorescent organic light-emitting diodes using a deep blue phosphorescent emitting material

A high efficiency pure white phosphorescent organic light-emitting diode was developed by combining a deep blue emitting phosphorescent dopant material with red/green phosphorescent emitting materials. A simple stack structure of blue/red:green was used and tris((3,5-difluoro-4-cyanophenyl)pyridine) iridium was used as a deep blue emitting phosphorescent dopant. A pure white emission with a color coordinate of (0.29, 0.31) and a very high current efficiency of 28 cd/A was obtained after managing the device architecture of the all phosphorescent white devices.     

Improved device performances in polymer light-emitting diodes using a stamp transfer printing process

The device performances of spin-coated and stamp transfer printed devices were compared. There was little difference of morphology between the spin-coated and stamp transfer printed devices. However, the stamp transfer printing process was better than the spin-coating process in terms of current density, light-emitting efficiency and lifetime. In particular, the lifetime of the stamp transfer printed device was doubled compared with that of the spin-coated device.     

High efficiency red phosphorescent organic light-emitting diodes using a spirobenzofluorene type phosphine oxide as a host material

High efficiency red phosphorescent organic light-emitting diodes have been developed using a spirobenzofluorene type phosphine oxide (SPPO2) as a host material. The SPPO2 had a high glass transition temperature of 119 °C and a smooth surface morphology with a surface roughness less than 1 nm. The red device with the SPPO2 as a host showed a quantum efficiency of 14.3% with a current efficiency of 20.4 cd/A.     

Fabrication of Ordered Nanostructured Arrays Using Poly(dimethylsiloxane) Replica Molds Based on Three‐Dimensional Colloidal Crystals

Hexagonally arrayed structures of colloidal crystals with uniform surface are a good candidate for master molds to be used in soft lithography. Here, the fabrication of periodically arrayed nanostructures using poly(dimethylsiloxane) (PDMS) molds based on three‐dimensionally (3D) ordered colloidal crystals is reported. A robust, high‐quality 3D colloidal‐crystal master molds is prepared using the colloidal suspension containing a water‐soluble polymer. The surface patterns of the 3D colloidal crystals can then be transferred onto a polymer film via soft lithography, by means of the replication of the surface pattern with PDMS. Various hexagonally arrayed nanostructure patterns can be fabricated, including close‐packed and non‐close‐packed 2D arrays and honeycomb structures by the structural modification of the 3D colloidal‐crystal templates. The replicated hexagonally arrayed structures can also be used as templates for producing colloidal crystals with 2D superlattices.     

Removal characteristics of nitrogen oxide of high temperature catalytic filters for simultaneous removal of fine particulate and NOx

The CuMnOx catalysts were deep coated into polysulfonamide felts by vacuum suction to simultaneously remove the particulate and nitrogen oxides. This filter consists of a high temperature foam layer as a surface layer, a catalytic pleated felt as a medium layer and glassfiber fabric layer with high temperature phenol resin as a final layer. In this study, the effects of catalyst loading on the pleated felt, operating temperature on nitrogen oxides reduction with NH₃ were mainly investigated. Tests were conducted at operating temperature range from 150 to 250 °C and at face velocity of 1 m/min. Within these ranges, NO removal efficiency was over 90% at the catalyst loading of 350 g/m² and 200 °C.     

Hole injection improvement by doping of organic material in copper phthalocyanine

Hole injection properties of copper phthalocyanine (CuPc) layer doped with hexaazatriphenylene–hexacarbonitrile (HAT) were studied by changing the doping concentration of HAT. Hole injection efficiency of CuPc layer was improved by doping of HAT as a p-dopant and a maximum current density was obtained at a HAT doping concentration of 10%. The use of HAT doped CuPc layer as a hole injection layer improved the current efficiency of green phosphorescent organic light-emitting diodes.     

Biotransformation of glycidol by the unspecific wax ester synthase/acyl‐CoA:diacylglycerol acyltransferase of Acinetobacter baylyi ADP1

Glycidol was biologically derivatized by the unspecific wax ester synthase/acyl coenzyme A (acyl‐CoA): diacylglycerol acyltransferase (WS/DGAT) from Acinetobacter baylyi ADP1 into glycidyl acyl ester. Catalysis of in vitro conversion of glycidol to glycidyl acyl ester by the WS/DGAT from A. baylyi was verified by (i) a radiometric assay, (ii) thin‐layer chromatography and (iii) also by ESI‐MS. A specific activity of 50 nmol·mg^–1·min^–1 was obtained when 10 mM glycidol and 5 µM palmitoyl‐CoA were used. In vivo synthesized glycidyl acyl esters in recombinant E. coli were detected and quantified by staining with the epoxide‐specific reagent 4‐(4‐nitrobenzyl)‐pyridine. Of glycidyl acyl esters, 1.5 mg/L was obtained from the culture in the presence of 10 mM glycidol and 10 mM oleate.