Addition of Titanium Oxide Inclusions into Liquid Steel to Control Nonmetallic Inclusions

Titanium oxide inclusions in steel are well known to inhibit grain growth and act as nucleation sites for acicular ferrite because of absorbing manganese from the surrounding steel resulting in a manganese depleted zone around the inclusion. In this article, the inclusions resulting from TiO₂ additions to low-alloyed C-Mn-Cr steel were studied. Different types of TiO₂ containing materials were added to liquid steel before or during casting to get small titanium-oxide–rich inclusions in steel. The main goals were to find out what happens to TiO₂ in liquid steel after addition and during cooling and to study further what type of inclusions are formed in the steel as a result of the TiO₂ addition. Based on the thermodynamic calculations and the results of scanning electron microscope (SEM)-energy dispersive spectroscope (EDS) and SEM-electron backscatter diffraction (EBSD) analysis, TiO₂ is first reduced to Ti₃O₅ in liquid steel at high temperatures and then to Ti₂O₃ during cooling at around 1573 K (1300 °C). Both reactions liberate oxygen, which reacts with Ti, Mn, and Al forming complex Ti₂O₃-rich inclusions. The results also show that TiO₂ additions result in more TiO_x + MnO inclusions compared with experiments with Ti addition and that the absolute amount of manganese present in the inclusions is much higher in experiments with TiO₂ addition than in experiments with Ti additions.     

Mechanical properties of near-eutectic Sn-Ag-Cu alloy over a wide range of temperatures and strain rates

The deformation properties of near-eutectic Sn-Ag-Cu alloy were measured in temperatures ranging from −25 to 125°C, and down to strain rates of about 10×10⁻⁹. Results have been combined into a stress versus strain rate master curve. The measurements were done with dog-bone specimens that have a 1-mm diameter, which corresponds to a typical solder joint diameter in ball grid arrays (BGAs). Effects of cooling rate were also studied, with cooling rates from 0.1 to 1 degrees/sec. The stress exponent of the fast-cooled samples was high, about 16. The activation energy was about 1 eV. The relatively high temperature dependence suggests that bulk diffusion is dominating. Optical microscopy, scanning electron microscopy (SEM) and electron backscattering diffraction (EBSD) were used to study the microstructures of the test samples. The slower cooled samples had large Ag3Sn plates, but the size of the plates was significantly reduced with the faster cooling rates. The yield strength increased with cooling rate, reflecting the larger amount of alloying elements remaining in the solution and smaller, dispersed precipitates. For comparison, experiments were also performed on binary AgSn and CuSn solders, pure Sn, and with two reduced silver content SAC alloys, Sn-2.5% Ag-0.7% Cu and Sn-3.0% Ag-0.7% Cu.     

Formation of a silver(I) coordination compound, with a pyrazole-pyridine ligand, whose crystal lattice is composed of three different types of 1D chains

Reaction of silver nitrate with the ligand 2-(1-Methyl-1H-pyrazol-5-yl)pyridine (1-mpp) produces a supramolecular material comprising three different types of one-dimensional coordination polymers as a result of two distinct orientations of the nitrate anions (with a 50/50 ratio) in the crystal lattice.     

Effects of reaction conditions on nuclear laundry water treatment in Fenton process

This study presents the efficiency of Fenton process in the degradation of organic compounds of nuclear laundry water. The influence of Fe(2+) and hydrogen peroxide ratio, hydrogen peroxide dose, pH and treatment time were investigated. The degradation of non-ionic surfactant and other organic compounds was analysed as COD, TOC and molecular weight distribution (MWD). The most cost-effective degradation conditions were at H(2)O(2)/Fe(2+) stoichiometric molar ratio of 2 with 5 min mixing and H(2)O(2) dose of 1000 mg l(-1). With the initial pH of 6, the reductions of COD and TOC were 85% and 69%, respectively. However, the removal of the organic compounds was mainly carried out by Fenton-based Fe(3+) coagulation rather than Fenton oxidation. Fenton process proved to be much more efficient than previously performed ozone-based oxidation processes.     

Sporulation Strategies and Potential Role of the Exosporium in Survival and Persistence of Clostridium botulinum

Clostridium botulinum produces the botulinum neurotoxin that causes botulism, a rare but potentially lethal paralysis. Endospores play an important role in the survival, transmission, and pathogenesis of C. botulinum. C. botulinum strains are very diverse, both genetically and ecologically. Group I strains are terrestrial, mesophilic, and produce highly heat-resistant spores, while Group II strains can be terrestrial (type B) or aquatic (type E) and are generally psychrotrophic and produce spores of moderate heat resistance. Group III strains are either terrestrial or aquatic, mesophilic or slightly thermophilic, and the heat resistance properties of their spores are poorly characterized. Here, we analyzed the sporulation dynamics in population, spore morphology, and other spore properties of 10 C. botulinum strains belonging to Groups I–III. We propose two distinct sporulation strategies used by C. botulinum Groups I–III strains, report their spore properties, and suggest a putative role for the exosporium in conferring high heat resistance. Strains within each physiological group produced spores with similar characteristics, likely reflecting adaptation to respective environmental habitats. Our work provides new information on the spores and on the population and single-cell level strategies in the sporulation of C. botulinum.     

Lingonberry juice improves endothelium-dependent vasodilatation of mesenteric arteries in spontaneously hypertensive rats in a long-term intervention

Phenolic compounds of berries, fruits and vegetables affect vascular health. Endothelium-dependent vasodilatation has an important role in blood pressure development by controlling the vascular tone. Endothelial cells produce and release various relaxing and contracting factors, like nitric oxide (NO), cyclo-oxygenase (COX)-derived prostanoids and endothelium-derived hyperpolarizing factor (EDHF). The purpose of this study was to investigate whether 8 weeks treatment with Finnish berry juices, cranberry (Vaccinium oxycoccos), lingonberry (Vaccinium vitis-idaea) and blackcurrant (Ribes nigrum) affects blood pressure and vascular function of spontaneously hypertensive rats (SHR). After 8 weeks treatment the mesenteric arteries of the rats were taken for vascular reactivity studies. Lingonberry treatment normalized the impaired endothelium-dependent relaxation seen in the cranberry, blackcurrant and control rats. In the arteries of lingonberry treated rats the relaxation was partly due to NO, but also dependent on EDHF. It can be concluded that long-term lingonberry juice treatment improves endothelium-dependent vasodilatation of SHR.     

Effects of cis-9,trans-11 CLA in rats at intake levels reported for breast-fed infants

CLA intake in exclusively breast-fed infants is close to levels found to have physiological effects in animals. However, in the majority of studies mixtures of CLA isomers have been used and the independent effects of the major CLA isomer in human milk, cis-9, trans-11 CLA, at the intake level in exclusively breast-fed infants have hardly been studied. We therefore studied the effects of cis-9, trans-11 CLA on plasma lipids and glucose, immune function, and bone metabolism in growing rats. Thirty male Sprague-Dawley rats (n=10/group) were fed either 20 mg/kg/d cis-9, trans-11 CLA and 20 mg/kg/d sunflower oil (CLA20), 40 mg/kg/d cis-9, trans-11 CLA (CLA40), or 40 mg/kg/d sunflower oil (placebo) for 8 wk. No significant differences between groups were found in plasma lipids, glucose, insulin, C-reactive protein, or lipid peroxidation. Liver fat content was lowest in the CLA20 group. In vitro interleukin 2 (IL-2) production increased, and tumor necrosis factor alpha, IL-1β, prostaglandin E₂, and leukotriene B₄ production decreased in the CLA20 group. No differences between groups were detected in IL-4, IL-6, or interferon gamma production, plasma osteocalcin, insulin-like growth factor, or urinary deoxypyridino line crosslinks. Plasma tartrate-resistant acid phosphatase 5b activity was significantly increased in the CLA40 group. The results indicate anti-inflammatory effects and enhanced T-cell function for the CLA20 group. No adverse effects were seen in the CLA20 group, whereas indications of increased bone resorption rate were observed in the CLA40 group.     

Optimization of 1,2,5‐Thiadiazole Carbamates as Potent and Selective ABHD6 Inhibitors

At present, inhibitors of α/β‐hydrolase domain 6 (ABHD6) are viewed as a promising approach to treat inflammation and metabolic disorders. This article describes the development of 1,2,5‐thiadiazole carbamates as ABHD6 inhibitors. Altogether, 34 compounds were synthesized, and their inhibitory activity was tested using lysates of HEK293 cells transiently expressing human ABHD6 (hABHD6). Among the compound series, 4‐morpholino‐1,2,5‐thiadiazol‐3‐yl cyclooctyl(methyl)carbamate (JZP‐430) potently and irreversibly inhibited hABHD6 (IC₅₀=44 nM ) and showed ～230‐fold selectivity over fatty acid amide hydrolase (FAAH) and lysosomal acid lipase (LAL), the main off‐targets of related compounds. Additionally, activity‐based protein profiling indicated that JZP‐430 displays good selectivity among the serine hydrolases of the mouse brain membrane proteome. JZP‐430 has been identified as a highly selective, irreversible inhibitor of hABHD6, which may provide a novel approach in the treatment of obesity and type II diabetes.     

Utilization of Cognitive Support in Episodic Free Recall as a Function of Apolipoprotein E and Vitamin B?? or Folate Among Adults Aged 75 Years and Older.

Apolipoprotein E (APOE), vitamin B??, and folate were examined in relation to free recall among 167 community-based older adults. Cognitive support at encoding and retrieval was also taken into account. Participants were classified as APOE e4 or non-e4 allele carriers and as either low or normal vitamin B?? or folate status. A significant association was identified between low vitamin B?? and the e4 genotype in respect to free recall, but only in circumstances of low cognitive support. This result remained after removing dementia cases that occurred up to 6 years after testing. A similar, but nonsignificant, trend was evident in relation to folate. The research is discussed with reference to vulnerability models and genetic influences on brain reserves. (PsycINFO Database Record (c) 2010 APA, all rights reserved)