Electron spin transport in a metal-oxide-semiconductor Si two-dimensional inversion channel: Effect of hydrogen annealing on spin scattering mechanism and spin lifetime

Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan Center for Spintronics Research Network (CSRN), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, JapanComment: 26 pages, 5 figures, 1 tabl

Effect of 3'-methyl-N,N-dimethyl-4-aminoazobenzene in the presence or absence of liver microsomes on the liver cells having low tumor-producing capacity in culture.

A cell strain having low tumor-producing capacity was exposed in culture to 3'-methyl-N,N-dimethyl-4-aminoazobenzene (3'-Me-DAB) in the presence or absence of liver microsomes, and whether or not the cells will progress to those having high tumor-producing capacity was examined. When transplanted into rats, the cells treated with 3'-Me-DAB four (Exp-I) or thirteen times (Exp-II) formed larger tumors than untreated control cells, the latter treatment being more efficient in this regard. Furthermore, the tumors formed by the cells treated with 3'-Me-DAB in the presence of liver microsomes were considerably larger than those formed by the cells treated with 3'-Me-DAB alone. The subcutaneous tumors produced by the cells treated with 3'-Me-DAB with S-15 Mix showed poorly differentiated histology compared with those produced by control and 3'-Me-DAB-treated cells. The frequency of lung metastasis tended to increase by 3'-Me-DAB with S-15 Mix. The cells treated with 3'-Me-DAB in the presence or absence of liver microsomes differed from untreated control cells in vitro in some properties, including the size of aggregates in rotation culture, plating efficiency in liquid medium and morphology. These observations suggest that cell malignancy was promoted by 3'-Me-DAB alone as well as by 3'-Me-DAB in the presence of liver microsomes.</p

Tourmaline in a Mesoarchean pelagic hydrothermal system: Implications for the habitat of early life

The RNA World hypothesis requires the synthesis of RNA to allow the emergence of life on Earth. Hydrothermal systems have been proposed as potential candidates for constructing complex biomolecules. However, in order to successfully form RNA, it is necessary to stabilize ribose, a RNA carbohydrate component. Borate has been found to stabilize ribose. Therefore, boron rich hydrothermal systems are important environments concerning the origin of life on Earth. The 3.2-Ga Dixon Island Formation of the West Pilbara Superterrane, Western Australia, is a volcano-sedimentary sequence. The Formation represents a Mesoarchean pelagic hydrothermal system, which formed adjacent to an immature island arc. Fine-grained tourmaline, in addition to biogenic carbonaceous matter and spherulitic and tubular bacteriomorphs, are found in black chert. A boron-rich environment was responsible for the formation of these deposits. To explore the implications of such a boron enriched environment on microbial activity, modes of occurrence and chemical compositions of the tourmaline were examined. The tourmaline is schorl or dravite of the alkali tourmaline group and the boron isotope compositions range in δ11B from -7.3 to +2.6‰. The tourmaline occurs in microcrystalline quartz matrix of black chert veins that cross cut a volcanic unit and also in a bedded black chert, which overlays the volcanic unit. The volcanic unit contains highly altered zones with hydrothermal veins. The associated lithologic and stratigraphic features suggest that the black chert veins were the conduits for upward moving hydrothermal fluids, which reached the sea floor. Subsequently, the volcanic unit was covered by organic matter-rich cherty sediments that in part were fed, and/or altered, by the hydrothermal fluids. These results suggest that the origin of boron enrichment to form Dixon Island tourmaline is not the associated sedimentary mineral assemblage, which includes diagenetic clay, low-grade metamorphic mica, and organic matter. Instead, the tourmaline was directly precipitated from hydrothermal fluid, enriched in boron. Furthermore, the hydrothermal fluids had already concentrated the boron, in the Mesoarchean pelagic system, prior to the apex of organic matter production and microbial activity. Our findings support a hypothesis that the boron-enriched hydrothermal environment aided the survival and evolution of early life

Suppressive effect of azithromycin on Plasmodium berghei mosquito stage development and apicoplast replication

<p>Abstract</p> <p>Background</p> <p>Azithromycin (AZM) is a macrolide antibiotic that displays an excellent safety profile even in children and pregnant women and has been shown to have anti-malarial activity against blood stage <it>Plasmodium falciparum</it>. This study evaluated the transmission-blocking effect of AZM using a rodent malaria model.</p> <p>Methods</p> <p>AZM-treated mice infected with <it>Plasmodium berghei </it>were exposed to <it>Anopheles stephensi </it>mosquitoes, followed by the observation of parasite development at different phases in the mosquito, i.e., ookinetes in the midgut, oocysts on the midgut, and sporozoites in the midgut and salivary glands. Furthermore, to evaluate the effect on organelle replication of each stage, quantitative real-time PCR analysis was performed.</p> <p>Results</p> <p>The inhibitory effect of AZM was noticeable in both gametocyte-ookinete transformation in the midgut and sporozoite production in the oocyst, while the latter was most remarkable among all the developmental phases examined. Real-time PCR analysis revealed that AZM suppressed apicoplast replication at the period of sporozoite production in oocysts.</p> <p>Conclusions</p> <p>AZM inhibits parasite development in the mosquito stage, probably through the same mechanism as in the liver and blood stages. Such a multi-targeting anti-malarial, along with its safety, would be ideal for mass drug administration in malaria control programmes.</p

On Subject Aux Inversion

0. Subject Aux Inversion (henceforth SAI) is a rule which inverts the order of subject and auxiliary. For example, it converts a sentence John would be happy into the corresponding interrogative Would John be happy? ..

Performance of a newly developed SDCCD for X-ray use

A Scintillator Deposited CCD (SDCCD) is a wide-band X-ray detector consisting of a CCD and a scintillator directly attached to each other. We assembled the newly developed SDCCD that the scintillator CsI(Tl) is below the fully depleted CCD. The incident X-rays enter the CCD depletion layer first. Then, X-rays passing through the depletion layer are absorbed in the CsI(Tl). The contact surface of the CCD is a back-illuminated side so that we can have good light collection efficiency. In our experimental setup, we confirmed good performance of our SDCCD detecting many emission lines up to 88\,keV that comes from $^{109}$Cd.Comment: 4 pages, 6 figures, accepted publication for Nucl. Instr. and Meth. (2010