Performance of ZrC-Coated Particle Fuel in Irradiation and Postirradiation Heating Tests

The ZrC-coated UO₂ particle is a promising fuel for high-temperature gas-cooled reactors. Particle fuels with multiple layers of pyrolytic carbon and ZrC have been irratiation-tested to a maximum fast-neutron fluence exceeding 2 × 10²⁵/m² ( E < 29 fJ). In-reactor fission-gas release measured at a burnup of 1.5 at.% was minimal. The failure fraction by postirradiation examination was null for all samples. The ZrC-coated particles at 4 at.% burnup were postirradiation heated to 2400°C/min without failure until after 6000 s at the maximum temperature. It was found that the ZrC layer could sustain a large strain at such high temperatures. The behavior is in strong contrast with that of SiC of standard Triso coating, which is brittle to very high temperatures.     

Familial aggregation and covariation of diseases in a Japanese rural community: comparison of stomach cancer with other diseases

PURPOSE: We investigated familial aggregation as well as familial covariation of diseases by means of a questionnaire survey dealing with family histories of stomach cancer, stroke, hypertension, diabetes and tuberculosis as well as life style among 2,769 inhabitants of a rural community (84% of census population). METHODS: The strength of familial aggregation was shown by an odds ratio (OR) that compared the number of families in which siblings suffered from one of the above diseases among families in which at least one parent suffered from it, and among families in which neither did. Probands were divided into two groups for analysis: an under-55 "young group," and a 55-and-older "old group." RESULTS: The OR for stomach cancer was lowest and insignificant in the young group, and significant (2.2, p < 0.05) only in the old group. The OR for stroke, hypertension, and tuberculosis was 4.5-5.1 (p < 0.05) in the young group but decreased to 2.3-3.2 in the old group. Diabetes increased from 3.9 to 5.7 (p < 0.05) with advancing age. Age-related OR trends were not affected by exposure to cigarette smoke in the past. Stomach cancer showed a borderline familial covariation with diabetes and a borderline inverse covariation with hypertension. Hypertension showed a familial covariation with stroke and diabetes. CONCLUSIONS: Among the investigated diseases, familial aggregation was weakest for stomach cancer. The results suggest that stomach cancer may share a common familial etiologic factor with diabetes and hypotension.     

Deposition of atmospheric (137)Cs in Japan associated with the Asian dust event of March 2002

Considerable deposition of (137)Cs was observed in the northwestern coastal area of Japan in March 2002. Since there were no nuclear explosions or serious nuclear accidents in the early 2000s, transport of previously contaminated dust appears to be the only plausible explanation for this event. In March 2002, there was a massive sandstorm on the East Asian continent, and the dust raised by the storm was transported across the sea to Japan. This dust originated in Mongolia and northeastern China, in an area distant from the Chinese nuclear test site at Lop Nor or any other known possible sources of (137)Cs. Our radioactivity measurements showed (137)Cs enrichment in the surface layer of grassland soils in the area of the sandstorm, which we attributed to accumulation as a result of past nuclear testing. We suggest that the grassland is a potential source of (137)Cs-bearing soil particles. Since the late 1990s, this area has experienced drought conditions, resulting in a considerable reduction of vegetation cover. We attribute the prodigious release of (137)Cs-bearing soil particles into the atmosphere during the sandstorm and the subsequent deposition of (137)Cs in Japan to this change.     

Reexamination of the Female Sex Pheromone of the Sweet Potato Vine Borer Moth: Identification and Field Evaluation of a Tricosatriene

The sweet potato vine borer moth, Omphisa anastomosalis (Pyraloidea: Crambidae), is a serious pest in tropical and subtropical Asia-Pacific regions. In previous work using a population from Okinawa, Japan, (10E,14E)-10,14-hexadecadienal (E10,E14-16:Ald) was identified as the major pheromone component, with hexadecanal, (E)-10-hexadecenal, and (E)-14-hexadecenal as minor components. However, traps baited with the synthetic compounds were less effective at attracting males in the field than those baited with virgin females. While Pyraloidea females usually produce only Type I pheromone components (unsaturated fatty alcohols and their derivatives), the pheromones of some Pyraloidea species have been shown to involve a combination of both Type I and Type II components (unsaturated hydrocarbons and their epoxides). We examined an extract of the pheromone glands of female O. anastomosalis from Vietnam by gas chromatography coupled to mass spectrometry and detected (3Z,6Z,9Z)-3,6,9-tricosatriene (Z3,Z6,Z9-23:H) in addition to the compounds identified previously. All four isomers of 10,14–16:Ald were synthesized. A mixture of synthetic E10,E14-16:Ald and Z3,Z6,Z9-23:H in a ratio of 1:0.2–1:2 was attractive to male moths in Vietnam, indicating the strong synergistic effect of the Type II compound. Addition of the other minor pheromone components to the binary blend did not increase the number of male moths captured. Combinations of Z3,Z6,Z9-23:H with the other three geometrical isomers of E10,E14-16:Ald attracted no males, further substantiating the 10E,14E configuration of the natural diene component. E10,E14-16:Ald mixed with other polyunsaturated hydrocarbons showed that mixtures that included a C₂₁ triene, a C₂₂ triene, or a C₂₃ pentaene attracted as many males as did the mixture with Z3,Z6,Z9-23:H. The identification of a highly attractive sex pheromone will help in developing efficient strategies for monitoring and control of O. anastomosalis populations in sweet potato fields.     

Preferential adsorption of bovine fibrinogen dimer onto polymer microspheres having heterogeneous surfaces consisting of hydrophobic and hydrophilic parts

The adsorption onto polymer microspheres of bovine fibrinogen (BFb) containing both dimeric and monomeric species was examined using various homopolymer, copolymer, and poly(2-hydroxyethyl methacrylate)/polystyrene composite microspheres which were produced by the emulsifier-free (seeded) emulsion polymerization technique. The preferential adsorption of the BFb dimer was clearly observed in an optimum region of the surface hydrophilicities of the polymer microspheres. The preferential adsorption of the BFb dimer onto the composite polymer microspheres having heterogeneous surfaces with both hydrophilic and hydrophobic parts was more remarkable than that onto the homopolymer and copolymer microspheres having homogeneous surfaces. The behavior is discussed in comparison with those for bovine serum albumin and human γ-globulin.     

Production of gamma-lactones by the brown-rot basidiomycete Piptoporus soloniensis

A wild strain of brown-rot basidiomycete Piptoporus soloniensis produced a sweet flavor similar to tropical fruits in liquid cultures. The major and minor compounds were identified to be gamma-decalactone and gamma-octanolactone by gas chromatography-mass spectrometry analysis, respectively. The growth and production of gamma-decalactone by P. soloniensis in broth to which fatty acids had been added were investigated. The addition of 12-hydroxystearic acid and ricinoleic acid to the culture markedly enhanced the production of gamma-decalactone. On the other hand, addition of myristic acid, palmitic acid, stearic acid and oleic acid to the culture resulted in a higher production of gamma-octanolactone. The addition of hexanoic acid, octanoic acid, decanoic acid, lauric acid, linoleic acid and linolenic acid to the culture reduced the growth of P. soloniensis and production of gamma-decalactone and gamma-octanolactone. This strain accumulated oxalic acid in liquid culture and grew sufficiently under strongly acidic conditions.     

Identification of Conjugated Pentadecadienals as Sex Pheromone Components of the Sphingid Moth, Dolbina tancrei

Homologs of bombykal, (10E,12Z)-10,12-hexadecadienal, have been reported to be sex pheromones or sexual attractants of several species of sphingid moths. In this study, we identified novel bombykal analogs as sex pheromone components from a Japanese sphingid moth, Dolbina tancrei. Staudinger (Sphingidae: Lepidoptera). Sex pheromone gland extracts from calling female moths were subjected to gas chromatography/electroantennograhic detection (GC/EAD), gas chromatography/mass spectrometry (GC/MS), and gas chromatography (GC) analyses. GC/EAD analyses showed two active components in the crude pheromone extracts. GC/MS analysis determined these two components to be pentadecadienals. GC/MS of their MTAD derivatives showed conjugated double bonds at the 9- and 11-positions, indicating 9,11-pentadecadienals. The isomeric configurations of these candidates were determined by comparison of their Kováts retention indices with those of synthetic compounds. Field bioassays with the four isomers of 9,11-pentadecadienal and their mixtures confirmed that the two sex pheromone components of D. tancrei are (9E,11Z)-9,11-pentadecadienal and (9Z,11Z)-9,11-pentadecadienal, with the highest male catches observed for a 90:10 blend. This is the first report of 9,11-pentadecadienals as sex pheromone components in lepidopteran species.     

Characterization of membrane bioreactor for dry wine production

Characteristics of yeast growth and ethanol fermentation were examined in membrane bioreactor using a grape juice. After inoculation, batch fermentation was carried out for 24 h. When yeast growth reached the stationary phase, continuous fermentation was initiated. In continuous fermentation, a linear relationship was observed between cell concentration and dilution rate. In single-vessel membrane bioreactor, the cell concentrations of 18.7 g/l and 76.9 g/l (15 and 60 times higher than that of the batch fermentation, respectively) were observed at dilution rates of 0.1 h(-1) and 0.3 h(-1), respectively. The residual sugar concentration was higher than 10 g/l at the dilution rate of 0.1 h(-1), 0.2 h(-1) or 0.3 h(-1), therefore the single-vessel membrane bioreactor was not suitable for producing dry wine (sugar concentration: 4 g/l or less). In the double-vessel membrane bioreactor, it is most suitable to set the recycle ratio at 0.15 for keeping the sugar concentration below 4 g/l. The productivity of dry wine in the double-vessel membrane bioreactor was 28 times higher than that in the batch fermentation.     

A Hydrogen Peroxide Activatable Gemcitabine Prodrug for the Selective Treatment of Pancreatic Ductal Adenocarcinoma

The main concern in the use of anticancer chemotherapeutic drugs is host toxicity. Patients need to interrupt or change chemotherapy due to adverse effects. In this study, we aimed to decrease adverse events with gemcitabine (GEM) in the treatment of pancreatic ductal adenocarcinoma and focused on the difference of hydrogen peroxide levels in normal versus cancer cells. We designed and synthesized a novel boronate-ester-caged prodrug that is activated by the high H₂O₂ concentrations found in cancer cells to release GEM. An H₂O₂-activatable GEM (A-GEM) has higher selectivity for H₂O₂ over other reactive oxygen species (ROS) and cytotoxic effects corresponding to the H₂O₂ concentration in vitro. A xenograft model of immunodeficient mice indicated that the effect of A-GEM was not inferior to that of GEM when administered in vivo. In particular, myelosuppression was significantly decreased following A-GEM treatment compared with that following GEM treatment.     

热氧老化对丁苯胶乳体系分散稳定性的影响

研究热氧老化对丁苯胶乳体系分散稳定性的影响。结果表明,老化过程中非离子表面活性剂氧化分解产生的羧酸导致了体系pH值的下降,使胶乳粒子表面电荷总量减少,削弱了粒子间的静电斥力;同时非离子表面活性剂的分解削弱了其提供的空间位阻效应,两种因素共同影响使丁苯胶乳的分散稳定性下降。