83 research outputs found
A laboratory experiment on the influence of aqueous alteration on noble gas compositions in the Allende meteorite
We have carried out a hydrothermal experiment on the Allende CV chondrite, in order to understand the observed noble gas loss from CM and CI chondrites, possibly caused by aqueous alteration on their parent bodies (L. B. Browning et al., Geochim. Cosmochim. Acta, 60,2621,1996; T. Nakamura et al., Geochim. Cosmochim. Acta, 63,257,1999). The Allende meteorite was disaggregated and kept with liquid water in a pressurized vessel under 15 atm of water vapor at 200℃ for a week. The abundances of helium, neon, argon, krypton and xenon in the samples have been measured by stepwise heating technique. The abundances of noble gases were decreased by 24% (He), 27% (Ne), 38% (Ar), 23% (Kr) and 34% (Xe) after the hydrothermal treatment, suggesting that the hot water treatment had contributed to reduce the concentrations of noble gases in Allende. This gas loss also affected the isotopic composition of xenon. For the 1200℃ fraction, the amount of ^Xe-HL was decreased from the sample by about 80% during the hot water treatment, while that of ^Xe-Q was decreased to a lesser extent (∿40%). This result seems to indicate that the carrier of Xe-HL is less resistant to the gas loss by the hot water alteration than phase Q for high temperature components. However, further studies are required as this trend becomes less obvious and rather similar if we take into consideration the xenon of 800℃ fraction
Tritium and iodine-129 concentrations in precipitation at Tsukuba, Japan, after the Fukushima Daiichi Nuclear Power Plant accident
The earthquake off the Pacific coast of Japan and the subsequent tsunami on March 11, 2011, triggered a series of accidents in the Fukushima Daiichi Nuclear Power Plant (FNPP1). The accidents caused the release of a mixture of radioactive substances into the environment. This study measured the concentration of tritium (3H) and iodine-129 (129I) in rainwater samples collected at Tsukuba, 170 km southwest of the plant, during the year following the accident. High 3H concentrations were observed in the rainwater samples collected within one month after the FNPP1 accident. 3H concentrations decreased steadily over time and returned to the levels before the accident. Concentrations of 129I also decreased over time. However, pulses of high 129I concentrations were observed at several other times following the accident. The 129I concentrations were found to be correlated with iron concentrations in rainwater. It is likely that iron oxide, which can absorb iodate ions (IO3–), was the carrier of radiogenic iodine. This study concludes that 129I and also 131I, which is one of the most harmful radionuclides produced in nuclear reactors, can be redistributed to the atmosphere in the months following the deposition of radiogenic iodine on the ground
Development of Bilayered Bone Marrow-derived Cell-Gelatin Grafts for Augmentation Cystoplasty and Reconstruction of Bladder Tissues in Rats
Background : This study attempted to produce a novel graft composed of bone marrow-derived mesenchymal cell (BMC) layer-gelatin sheets for bladder augmentation cystoplasty. Then, we determined if the grafts could reconstruct bladder tissues. Methods : BMCs harvested from the femurs of green fluorescence protein (GFP)-transfected Sprague-Dawley (SD) rats were adherent and proliferating cells on collagen dishes. The cells were then cultured on temperatureresponsive culture dishes. Following this, the BMCs maintaining cell-cell contacts within the monolayer itself were applied to a gelatin sheet. Two BMC layer-gelatin sheets were overlaid together with the cell sides juxtaposed with one another (bilayered BMC-gelatin graft). Bladder top of SD rats were incised and transplanted with the bilayered BMC-gelatin grafts. Similarly, urinary bladders irradiated with 2 Gy once a week for 5 weeks were also conducted. As control, bilayered acellular-gelatin grafts were used. At 4 weeks after transplantation, the bladders were histologically investigated. Results : At 4 weeks after transplantation into either normal or radiation-injured urinary bladders, incised regions closed. The closed regions of bladder top had reconstructed tissues that were formed with urothelium, and smooth muscle layers. Within the reconstructed tissues, the thickness of the smooth muscle layers in the bilayered BMC-gelatin graft-transplanted bladders were larger compared to controls. The GFP-positive transplanted BMCs were detected. Some of the cells were simultaneously positive for smooth muscle or nerve cell markers. Conclusion : This study showed that the bilayered BMC-gelatin grafts that were experimentally produced could reconstruct bladder tissues. The grafts would be developed as grafts for bladder augmentation cystoplasty.Article信州医学雑誌 71(3) : 167-177, (2023)journal articl
Genotipagem, sorotipagem e determinação de mating-type de isolados clínicos de Cryptococcus neoformans do Estado de São Paulo, Brasil
The basidiomycetous yeast Cryptococcus neoformans is an important fungal pathogen mainly in immunocompromised patients. In this study, 47 clinical isolates of C. neoformans from regions of São Paulo State were studied serologically by using the Crypto Check Iatron RM 304-K kit, their genetic diversity was estimated by PCR-fingerprinting with a microsatellite-specific sequence (GACA)4, RAPD with primer 6 (Amersham Pharmacia Biotech), PCR-restriction fragment length polymorphism (RFLP) analysis of the phospholipase B gene (PLB1) digested with AvaI and mating type analysis by PCR. All 47 strains isolated from HIV positive patients included in this study were serotype A and MATalpha. The majority of the isolates (45/47) were VNI and only two were VNII by PCR-fingerprinting and PCR-RFLP analysis. High degree of homogeneity was observed when (GACA)4 was used, being highly correlated (>; 0.9). In contrast, the RAPD analysis was more heterogeneous with higher number of molecular profiles. By PCR-RFLP, no new molecular type was found, enhancing the suggestion that the differences based on conserved gene as PLB1, can be resultant of ongoing divergent evolution within the C. neoformans complex, into the current eight subtypes. Our results furnish new information on the molecular epidemiology of C. neoformans in the southeast region of Brazil.Cryptococcus neoformans, pertencente à classe dos basidiomicetos, é um importante patógeno, principalmente em pacientes imunocomprometidos. Neste estudo, 47 isolados clínicos de C. neoformans de várias regiões do Estado de São Paulo foram avaliados quanto aos sorotipos e ao mating-type por PCR. A diversidade genética foi analisada por PCR-fingerprinting com a seqüência iniciadora específica para regiões microssatélite (GACA)4, RAPD com o iniciador 6 (Amersham Pharmacia Biotech) e por RFLP do gene PLB1 digerido com AvaI. Todos os isolados foram obtidos de pacientes HIV positivos e identificados como sorotipo A e MATalfa. A maioria dos isolados pertencia ao tipo molecular VNI (45/47) e apenas dois foram VNII quando analisados por PCR-fingerprinting e PCR-RFLP. Homogeneidade alta foi obtida com o iniciador (GACA)4, com a maioria dos isolados apresentando correlação alta (>; 0.9). Os resultados do RAPD, por sua vez, revelaram maior heterogeneidade com número maior de perfis moleculares. Por PCR-RFLP, nenhum tipo molecular novo foi encontrado, realçando a idéia de que em genes conservados como PLB1, as diferenças podem ser resultantes de divergências evolutivas dentro do complexo C. neoformans, separando os isolados nos oito subtipos moleculares já estabelecidos. Nossos resultados fornecem novas informações sobre a epidemiologia molecular de C. neoformans na região sudeste do Brasil
Photoacoustic in vivo 3D imaging of tumor using a highly tumor-targeting probe under high-threshold conditions
Three-dimensional (3D) representation of a tumor with respect to its size, shape, location, and boundaries is still a challenge in photoacoustic (PA) imaging using artificial contrast agents as probes. We carried out PA imaging of tumors in mice using 800RS-PMPC, which was obtained by coupling of 800RS, a near-infrared cyanine dye, with PMPC, a highly selective tumor-targeting methacrylate polymer having phosphorylcholine side chains, as a probe. The conjugate 800RS-PMPC forms compact nanoparticles (dDLS = 14.3 nm), retains the biocompatibility of the parent polymer (PMPC) and exhibits unprecedented PA performance. When applied to mice bearing a 6 × 3 × 3 mm3 tumor buried 6 mm beneath the skin, the probe 800RS-PMPC selectively accumulates in the tumor and emits PA signals that are strong enough to be unambiguously distinguished from noise signals of endogenous blood/hemoglobin. The PA image thus obtained under high-threshold conditions allows 3D characterization of the tumor in terms of its size, shape, location, and boundaries
Social entrepreneurship: problems and ways of their solution
For modern constantly developing societies, it is normal to create categories in the process of the activity of the participants of socio-economic processes themselves. Practice is theoretical, and theory is pragmatic, because it creates those concepts in which «practice» exists and develops. Such a category is "social entrepreneurship", which is "umbrella" for a number of socio-economic phenomena. The general term for social entrepreneurship includes those types of entrepreneurial activity that contradict the traditional notion of entrepreneurship as an activity of independent economic entities aimed at maximizing their profits. The development of social entrepreneurship is an indicator of the quality of the business climate in the region and requires a set of measures to ensure the mechanism and access of non-governmental organizations to the provision of services in the social sphere, the provision of state support to socially-oriented non-profit organizations, and the promotion of the development of PPP practices in the social sphere
RNA interference in Lepidoptera: an overview of successful and unsuccessful studies and implications for experimental design
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Introduction of mitochondrial DNA from Pleurotus ostreatus into Pleurotus pulmonarius by interspecific protoplast fusion
RNA interference in Lepidoptera: An overview of successful and unsuccessful studies and implications for experimental design
Synthesis of rhodium–carbonyl complexes bearing a novel P,N-chelating ligand of Schiff-base type
Schiff-base type N, P-chelating ligands, phosphorus analogues of imino–anilido ligands, were designed and synthesized as a new type of ligands toward transition metals, and the rhodium–carbonyl complexes bearing the novel imino–phosphido and phosphaalkenyl-anilido ligands were synthesized as stable crystalline compounds. Their structures were definitively revealed by X-ray crystallographic analysis, showing the unique electronic features of the ligands. In addition, the effective trans-influence of the phosphorus atom was suggested on the basis of the structural parameters and spectroscopic features of the isolated complexes
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