Hydrogen cracking of ferritic stainless steel thermal storage tanks

A ferritic stainless steel (SUS436L), which was subjected to various kinds of reduction ratio was precharged with hydrogen at 40°C in 15% HCl solution by employing galvanic reaction with zinc. Tensile tests were performed in air at room temperature on both uncharged and charge specimens. Finite element method (FEM) analyses were carried out to obtain strain at panel corners under various different internal radii in a thermal storage tank when it was subjected to internal pressure. As a result, it was found that the value of internal corner radius?thickness of the panel (R?t) should be more than about 2 in order to prevent hydrogen embrittlement cracking.     

Prevalence and characterization of antimicrobial resistance of foodborne Listeria monocytogenes isolates in Hebei province of Northern China, 2005-2007

A total of 2177 food samples collected from nine cities in northern China during 2005 to 2007 were screened for the presence of Listeria monocytogenes. All L. monocytogenes isolates were subjected to serotyping, antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), as well as PCR screening to identify genes responsible for tetracycline resistance [tet(L), tet(M), tet(K), tet(S) and tet(B)], transposon Tn916, and class 1 integron. Contamination with L. monocytogenes was detected in 4.13% (90/2177) of the total samples representing various food products. The pathogen was mainly isolated from frozen food made of wheat flour or rice products (26/252, 10.32%) and raw meat products (46/733, 6.28%). Besides, 3.31% (10/302) of cooked meat, 1.17% (4/343) of seafood, 0.98% (2/204) of non-fermented bean products and 0.62% (2/323) of vegetables samples were contaminated by this bacterium. The L. monocytogenes isolates belonged to five serotypes (1/2a, 1/2b, 1/2c, 4b, and 3a), with serotype 1/2a being dominant (48.88%). Antimicrobial resistance was most frequently observed for ciprofloxacin (17.8%), tetracycline (15.6%) and streptomycin (12.2%). Overall, resistance was observed against 14 out of 18 antimicrobials tested while multiple resistances occurred among 18.9% (17/90) isolates. Interestingly, two isolates were resistant to more than five antimicrobials. Among 14 tetracycline-resistant isolates, 13 carried tet(M) gene including nine possessing Tn916, and one harbored tet(S) gene. PFGE analysis revealed genetic heterogeneity among individual serotypes as well as scattered occurrence of some genotypes without any clear-cut correlation to source or food type. The widespread distribution of epidemiologically important serotypes (1/2a, 1/2b and 4b) of L. monocytogenes, and their resistance to commonly used antibiotics indicate a potential public health risk. Our data also indicate that L. monocytogenes could act as a reservoir of mobile tet genes along the food chain.     

Thermoelectric Properties of NdGd<Subscript>1+<Emphasis Type="Italic">x</Emphasis></Subscript>S<Subscript>3</Subscript> Prepared by CS<Subscript>2</Subscript> Sulfurization

Ternary rare-earth sulfides NdGd_1+x S₃, where 0 ≤ x ≤ 0.08, were prepared by sulfurizing Ln₂O₃ (Ln = Nd, Gd) with CS₂ gas, followed by reaction sintering. The sintered samples have full density and homogeneous compositions. The Seebeck coefficient, electrical resistivity, and thermal conductivity were measured over the temperature range of 300 K to 950 K. All the sintered samples exhibit a negative Seebeck coefficient. The magnitude of the Seebeck coefficient and the electrical resistivity decrease systematically with increasing Gd content. The thermal conductivity of all the sintered samples is less than 1.9 W K⁻¹ m⁻¹. The highest figure of merit ZT of 0.51 was found in NdGd_1.02S₃ at 950 K.     

Nanoimprinting using release-agent-coated resins

A fluorinated self-assembled monolayer (F-SAM) is mainly used as the antisticking layer. To prevent the F-SAM coated on the nanoimprint lithography (NIL) mold from deteriorating, we propose a new form of nanoimprinting using a release-agent-coated resin. The results from measuring the surface free energy and observations by scanning probe microscopy (SPM) confirmed that the surface free energy, frictional force, and adhesion force of the release-agent spray-coated polymethylmethacrylate (PMMA) were lower than those of PMMA. To prove the release-agent spray-coated PMMA had a releasing effect, we tried to undertake thermal nanoimprinting on it using a mold without F-SAM. The pattern was clearly imprinted on the resin without any signs of adhesion.     

Effect of a hepatocyte growth factor/heparin-immobilized collagen system on albumin synthesis and spheroid formation by hepatocytes

A hepatocyte growth factor (HGF)/heparin-immobilized collagen system was used as a synthetic extracellular matrix for hepatocyte culture. The albumin synthesis, nucleus numbers and morphology of the hepatocytes were determined separately to evaluate the hepatocyte number and hepatocyte-specific function under this system. The benefits of the HGF/heparin-immobilized collagen system for hepatocyte culture were confirmed by three types of culture methods in vitro, namely 2D film cultures, 2D gel cultures and 3D gel cultures. In 2D collagen film cultures, hepatocytes exhibited the highest albumin synthesis (1.42 μg/well/day) in HGF/heparin-immobilized collagen films at 7 days of culture. Heparin inhibited hepatocyte adhesion while HGF promoted hepatocyte migration, and spheroid formation was easily detected in HGF/heparin-immobilized collagen films. In 2D collagen gel cultures, albumin synthesis of around 15 μg/well/day was detected and maintained for more than 18 days on HGF/heparin-immobilized collagen gels. Similar findings were obtained in 3D HGF/heparin-immobilized collagen gel cultures, which exhibited albumin synthesis of up to 30 μg/well/day. The albumin synthesis by hepatocytes was two-fold higher in 3D gel cultures compared with 2D gel cultures, and was maintained for over 2 weeks compared with 2D film cultures using the HGF/heparin-immobilized collagen system. Taken together, the HGF/heparin-immobilized collagen system was effective for albumin synthesis by hepatocytes in both 2D film cultures and 3D gel cultures, and therefore shows good potential for tissue engineering use.     

Contrasting diurnal variations in fossil and nonfossil secondary organic aerosol in urban outflow, Japan

Diurnal variations of fossil secondary organic carbon (SOC) and nonfossil SOC were determined for the first time using a combination of several carbonaceous aerosol measurement techniques, including radiocarbon (1?C) determinations by accelerator mass spectrometry, and a receptor model (chemical mass balance, CMB) at a site downwind of Tokyo during the summer of 2007. Fossil SOC showed distinct diurnal variation with a maximum during daytime, whereas diurnal variation of nonfossil SOC was relatively small. This behavior was reproduced by a chemical transport model (CTM). However, the CTM underestimated the concentration of anthropogenic secondary organic aerosol (ASOA) by a factor of 4-7, suggesting that ASOA enhancement during daytime is not explained by production from volatile organic compounds that are traditionally considered major ASOA precursors. This result suggests that unidentified semivolatile organic compounds or multiphase chemistry may contribute largely to ASOA production. As our knowledge of production pathways of secondary organic aerosol (SOA) is still limited, diurnal variations of fossil and nonfossil SOC in our estimate give an important experimental constraint for future development of SOA models.     

Production of recombinant tumor necrosis factor receptor/Fc fusion protein by genetically manipulated chickens

We previously reported the production of recombinant proteins using genetically manipulated chickens and quails. In this study, we constructed a retroviral vector encoding an expression cassette for a fusion protein of the extracellular domain of the human tumor necrosis factor (TNF) receptor 2 and Fc region of human IgG1 (TNFR/Fc), which is expected as an effective drug for inflammatory diseases such as rheumatoid arthritis. The concentrated viral vector was injected into developing chicken embryos. The chickens that hatched stably produced TNFR/Fc in the serum and egg yolk for six months. It appears that the fused protein is transported and accumulated into yolk from the serum, which is mediated by the Fc receptor. The protein purified from the yolk and serum inhibited the cytotoxic activity of TNF-* toward L929 cells, indicating that the protein produced by the chickens is biologically active. These results indicate the effectiveness of the recovery of Fc-fused proteins from the yolk of genetically manipulated chickens.     

Structure-Based Design,Synthesis, and Biological Evaluation of Imidazo[4,5-b]Pyridin-2-one-Based p38 MAP Kinase Inhibitors: Part 2

We identified novel potent inhibitors of p38 mitogen-activated protein (MAP) kinase using a structure-based design strategy, beginning with lead compound, 3-(butan-2-yl)-6-(2,4-difluoroanilino)-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one ( 1 ). To enhance the inhibitory activity of 1 against production of tumor necrosis factor-α (TNF-α) in human whole blood (hWB) cell assays, we designed and synthesized hybrid compounds in which the imidazo[4,5-b]pyridin-2-one core was successfully linked with the p-methylbenzamide fragment. Among the compounds evaluated, 3-(3-tert-butyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-6-yl)-4-methyl-N-(1-methyl-1H-pyrazol-3-yl)benzamide ( 25 ) exhibited potent p38 inhibition, superior suppression of TNF-α production in hWB cells, and also significant in vivo efficacy in a rat model of collagen-induced arthritis (CIA). In this paper, we report the discovery of potent, selective, and orally bioavailable imidazo[4,5-b]pyridin-2-one-based p38 MAP kinase inhibitors.