Distribution of radioactive nuclides of boring core samples extracted from concrete structures of reactor buildings in the Fukushima Daiichi Nuclear Power Plant

Since the start of the severe accidents at the Fukushima Daiichi Nuclear Power Plant in March 2011, concrete surfaces within the reactor buildings (RBs) have been exposed to radioactive contaminants. Released radionuclides still remain too high to permit entry into some areas of the RBs to allow the damage to be assessed and to allow carrying out the restoration of lost safety functions, decommissioning activities, etc. In order to clarify the situation of this contamination in the RBs of Units 1, 2 and 3, samples of contaminants were collected and subjected to analyses to determine the surface radionuclide concentrations and to characterize the radionuclide distributions in the samples. Especially, decontamination tests on the boring core sample of Unit 2 were conducted to quantitatively determine the effectiveness of several basic decontamination techniques. As a result of the tests, the level of radioactivity of this sample was reduced with the removal of ～97% of the contamination present near the sample surface, and it was confirmed for the boring core sample that the contamination mainly had the characteristics of fixed contamination of the surface.     

Thermoelectric Efficiency of Reduced SrTiO3 Ceramics Modified with La and Nb

Ceramics of La_xSr_1?xNb_yTi_1?yO₃ (LSNT) were synthesized under various reducing atmospheres. Covering the specimens with graphite carbon felt under an Ar‐gas flow during sintering drastically enhanced the electrical conductivity, σ. Ti K‐edge absorption spectra indicated the presence of Ti³⁺ for heavily reduced specimens. The increase in conductivity was attributed to the 3d band of Ti³⁺. The maximum value for the figure of merit, ZT, was obtained for strontium titanate ceramics modified with both 5 mol% La and 5 mol% Nb, namely 5/5‐LSNT, exhibiting a ZT value of ~0.221 at 473 K. This high ZT value was almost 1.5 × larger than that of the conventional 10 mol% La‐doped sample, 10/0‐LSNT (ZT~0.144), and was mainly attributed to the larger Seebeck coefficient of the material.     

Bilateral thoracoscopic minimally invasive direct coronary artery bypass grafting using internal thoracic arteries

BACKGROUND: Single-vessel coronary artery bypass grafting of the left internal mammary artery (ITA) to the left anterior descending coronary artery using a minithoracotomy has been shown to produce excellent results with a very low mortality. However, this procedure cannot be used in patients with double- or triple-vessel disease. Our goal was to develop a minimally invasive direct coronary artery bypass grafting procedure without cardiopulmonary bypass for patients with multivessel disease. METHODS: Both ITAs were thoracoscopically harvested using video imaging. Limited bilateral anterior thoracotomies were performed in the fourth intercostal spaces, thus exposing the right coronary artery and the left anterior descending coronary artery. The right ITA-right coronary artery and ITA-left anterior descending coronary artery anastomoses were performed without cardiopulmonary bypass using 8-0 polypropylene sutures. RESULTS: This procedure was successfully performed in 3 patients. The patients were extubated in the operating room. Postoperative angiographic studies showed patent left ITA and right ITA grafts. CONCLUSIONS: Bilateral thoracoscopic minimally invasive direct coronary artery bypass grafting can be used to treat patients with a proximally diseased left anterior descending coronary artery and right coronary artery. Bilateral thoracoscopic ITA harvesting is a less invasive surgical technique that may become an option for the management of multivessel coronary artery disease.     

Radioimmunoassay for a novel lignan-related hypocholesterolemic agent, S-8921, in human plasma after high-performance liquid chromatography purification and in human urine after immunoaffinity extraction

The novel compound methyl-1-(3,4-dimethoxyphenyl)-3-(3-ethylvaleryl)-4-hydroxy-6,7,8- trimethoxy-2-naphthoate (S-8921) has hypocholesterolemic activity in animals and is expected to exhibit a similar activity in human. Reversed-phase high-performance liquid chromatography (HPLC) separation followed by radioimmunoassay (RIA) for human plasma samples (HPLC-RIA) and immunoaffinity extraction (IAE) followed by RIA for human urine samples (IAE-RIA) were developed for investigation of S-8921 behavior in clinical studies. For the RIA, antisera from rabbit and a radioiodine-labelled S-8921 were prepared by immunizing a conjugate of S-8921 with bovine serum albumin and by the Bolton and Hunter method, respectively. HPLC-RIA using a semi-micro column was very sensitive, that is a 0.05 ng/ml limit of quantitation in human plasma, and specific for unchanged form of S-8921. IAE-RIA using a centrifugal filtration tube completely eliminated the matrix effect of human urine, and was very feasible. The limit of quantitation was 0.10 ng/ml. RIA detection following HPLC or IAE proved to be very useful for the pharmaceutical analysis of extremely low drug concentrations in body fluids.     

Identification of a New Diterpene Biosynthetic Gene Cluster that Produces O‐Methylkolavelool in Herpetosiphon aurantiacus

Diterpenoids are usually found in plants and fungi, but are rare in bacteria. We have previously reported new diterpenes, named tuberculosinol and isotuberculosinol, which are generated from the Mycobacterium tuberculosis gene products Rv3377c and Rv3378c. No homologous gene was found at that time, but we recently found highly homologous proteins in the Herpetosiphon aurantiacus ATCC 23779 genome. Haur_2145 was a class II diterpene cyclase responsible for the conversion of geranylgeranyl diphosphate into kolavenyl diphosphate. Haur_2146, homologous to Rv3378c, synthesized (+)‐kolavelool through the nucleophilic addition of a water molecule to the incipient cation formed after the diphosphate moiety was released. Haur_2147 afforded (+)‐O‐methylkolavelool from (+)‐kolavelool, so this enzyme was an O‐methyltransferase. This new diterpene was indeed detected in H. aurantiacus cells. This is the first report of the identification of a (+)‐O‐methylkolavelool biosynthetic gene cluster.     

Pubertal maturation and early substance use risks among African American children.

Using 2 waves of longitudinal data collected from approximately 870 African American adolescents, this study examined (a) changes in early risk factors for substance use during transition to early adolescence, including perceived prototypes of substance-using peers, willingness and intention to use substances, number of substance-using peers, and youths' own actual substance use; (b) the relationship between pubertal timing and these substance use risks; and (c) the interaction between pubertal timing and peer substance use in predicting the risks. Results showed that, first, risks for substance use increased, particularly among girls, during the transition to early adolescence. Children's prototypic images of substance users became increasingly favorable during this transitional period; a greater number of them were willing and intended to use substances during the transition to early adolescence; and an increased number of early adolescents and their friends began to use substances. Second, these changes were significantly more likely to occur among early maturing girls. Third, early physical maturation interacted with peer substance use to affect these changes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)