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排序方式: 共有430条查询结果,搜索用时 13 毫秒
41.
Sato M Ishikawa T Ujihara N Yoshida S Fujita M Mochizuki M Asada A 《Science (New York, N.Y.)》2011,332(6036):1395
The moment magnitude (M(w)) = 9.0 2011 Tohoku-Oki mega-thrust earthquake occurred off the coast of northeastern Japan. Combining Global Positioning System (GPS) and acoustic data, we detected very large sea-floor movements associated with this event directly above the focal region. An area with more than 20 meters of horizontal displacement, that is, four times larger than those detected on land, stretches several tens of kilometers long along the trench; the largest amount reaches about 24 meters toward east-southeast just above the hypocenter. Furthermore, nearly 3 meters of vertical uplift occurred, contrary to observed terrestrial subsidence. 相似文献
42.
Matsuishi S Toda Y Miyakawa M Hayashi K Kamiya T Hirano M Tanaka I Hosono H 《Science (New York, N.Y.)》2003,301(5633):626-629
We removed approximately 100% of clathrated oxygen ions from the crystallographic cages in a single crystal of 12CaO.7Al2O3, leading to the formation of high-density (approximately 2 x 10(21) cm-3) electrons highly localized in the cages. The resulting electron forms a structure that we interpret as an F+ center and migrates throughout the crystal by hopping to a neighboring cage with conductivity approximately 100 siemens per centimeter, demonstrating that the encaged electron behaves as an anion. The electron anions couple antiferromagnetically with each other, forming a diamagnetic pair or singlet bipolaron. The resulting [Ca24Al28O64]4+(4e-) may be regarded as a thermally and chemically stable single crystalline "electride." 相似文献
43.
Yurimoto H Abe K Abe M Ebihara M Fujimura A Hashiguchi M Hashizume K Ireland TR Itoh S Katayama J Kato C Kawaguchi J Kawasaki N Kitajima F Kobayashi S Meike T Mukai T Nagao K Nakamura T Naraoka H Noguchi T Okazaki R Park C Sakamoto N Seto Y Takei M Tsuchiyama A Uesugi M Wakaki S Yada T Yamamoto K Yoshikawa M Zolensky ME 《Science (New York, N.Y.)》2011,333(6046):1116-1119
Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid. 相似文献
44.
Ken‐ichi YAMANAKA Masahiro KANEDA Yasushi INABA Koji SAITO Kaiyu KUBOTA Miki SAKATANI Satoshi SUGIMURA Kei IMAI Shinya WATANABE Masashi TAKAHASHI 《Animal Science Journal》2011,82(4):523-530
Many observations have been made on cloned embryos and on adult clones by somatic cell nuclear transfer (SCNT), but it is still unclear whether the progeny of cloned animals is presenting normal epigenetic status. Here, in order to accumulate the information for evaluating the normality of cloned cattle, we analyzed the DNA methylation status on satellite I region in blastocysts obtained from cloned cattle. Embryos were produced by artificial insemination (AI) to non‐cloned or cloned dams using semen from non‐cloned or cloned sires. After 7 days of AI, embryos at blastocyst stage were collected by uterine flushing. The DNA methylation levels in embryos obtained by using semen and/or oocytes from cloned cattle were similar to those in in vivo embryos from non‐cloned cattle. In contrast, the DNA methylation levels in SCNT embryos were significantly higher (P < 0.01) than those in in vivo embryos from non‐cloned and cloned cattle, approximately similar to those in somatic cells used as donor cells. Thus, this study provides useful information that epigenetic status may be normal in the progeny of cloned cattle, suggesting the normality of germline cells in cloned cattle. 相似文献
45.
46.
Sakatani M Yamanaka K Kobayashi S Takahashi M 《The Journal of reproduction and development》2008,54(6):496-501
Heat shock is known to increase the mortality of early stage embryos, but the exact mechanism is unclear. In the present study, we investigated the possibility that the increased mortality is caused by heat shock-generated reactive oxygen species (ROS). The level of ROS was controlled by using beta-mercaptoethanol (beta-ME), a scavenger of ROS. In vitro-produced 8-cell stage embryos were cultured at 38.5 C or heat-shocked by exposure to 41 C for 6 h with 0, 10 and 50 microM beta-ME. Intracellular ROS levels were measured by a fluorescent dye, 2',7'-dichlorodihydrofluorescein diacetate (DCHFDA), and intracellular reduced form of glutathione (GSH) contents were estimated by another fluorescent dye, 4-chloromethyl-6,8-difluoro-7-hydroxycoumarin. Total glutathione content was estimated by the glutathione recycling assay. On day 8 after insemination, heat shock decreased the percentage of embryos that developed to the blastocyst stage and increased intracellular ROS levels, but there was no significant effect on the GSH and total glutathione contents. In contrast, beta-ME significantly decreased ROS levels in heat-shocked embryos and increased the GSH and total glutathione concentrations. Ten microM beta-ME significantly improved the viability of heat-shocked embryos. beta-ME caused no detrimental effects when it was added at normal culture temperature (38.5 C). These results indicate that ROS is the primary cause of increased embryonic mortality in heat-shocked early stage embryos. 相似文献
47.
Tomoaki ONODA Ryuta YAMAMOTO Kyohei SAWAMURA Harutaka MURASE Yasuo NAMBO Yoshinobu INOUE Akira MATSUI Takeshi MIYAKE Nobuhiro HIRAI 《Journal of Equine Science》2013,24(4):63-69
Percentile growth curves are often used as a clinical indicator to evaluate variations of
children’s growth status. In this study, we propose empirical percentile growth curves
using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the
seasonal compensatory growth that is a typical characteristic of seasonal breeding
animals. We previously developed new growth curve equations for Japanese Thoroughbreds
adjusting for compensatory growth. Individual horses and residual effects were included as
random effects in the growth curve equation model and their variance components were
estimated. Based on the Z-scores of the estimated variance components, empirical
percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age
measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and
age measurements were used in the analyses. The developed empirical percentile growth
curves using Z-scores are computationally feasible and useful for monitoring individual
growth parameters of body weight and withers height of young Thoroughbred horses,
especially during compensatory growth periods. 相似文献
48.
Himaki T Mizobe Y Tsuda K Suetomo M Yamakuchi H Miyoshi K Takao S Yoshida M 《The Journal of reproduction and development》2012,58(4):398-403
The objective of this study was to examine the effect of postactivation treatment with latrunculin A (LatA), an actin polymerization inhibitor, on in vitro and in vivo development of somatic cell nuclear transfer (SCNT) embryos derived from kidney fibroblasts of an aged Clawn miniature boar (12 years old). After electric activation, SCNT embryos were treated with 0, 0.5 or 1 μM LatA and cultured in vitro. The rate of blastocyst formation was significantly higher (P<0.05) in SCNT embryos treated with 0.5 μM LatA (38%) than those in control (14%). When cloned embryos treated with 0.5 μM LatA were transferred into the oviducts of two recipient miniature gilts to assess their development in vivo, both recipients became pregnant; one maintained pregnancy to term, and a live piglet (weighing 220 g) was delivered by Caesarean section. The results of this study indicated that the postactivation treatment with LatA was effective in improving in vitro developmental capacity of SCNT miniature pig embryos derived from kidney fibroblasts of an aged animal and that miniature pig cloned embryos treated with LatA had the ability to develop to term. 相似文献
49.
Atsuko Murai Soichi Maruyama Masahiko Nagata Masashi Yuki 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2013,42(3):377-381
A 2‐year, 7‐month‐old female Chihuahua was admitted for a mammary mass measuring one cm in diameter. The dog had a history of demodicosis for 4 months and showed signs of pseudopregnancy at the time of the visit. Cytologic examination of an aspirate of the mass revealed a large number of macrophages containing nonstaining bacterial rods, which were acid‐fast in a Ziehl–Neelsen stain, suggesting mycobacterial infection. Histologic examination of the mass revealed a pyogranulomatous mastitis characterized by an infiltration with macrophages containing acid‐fast bacteria. Mycobacterium kansasii was subsequently cultured and identified by PCR. Surgical excision of the mass resulted in the growth of other dermal masses, but antimycobacterial treatment with rifampin and clarithromycin resolved these masses within 1 month. Three months after discontinuation of the treatment, similar organisms were found in aspirates of the enlarged bilateral inguinal lymph nodes by cytologic examination. Despite antimycobacterial treatment for another 4 months, there was no improvement and demodicosis also recurred. The dog eventually died of lymphoma 5 months after the relapse of mycobacterial infection. Although M kansasii is considered an important pathogen for pulmonary and cutaneous disease in people, there is only one report in a dog with an infection in a pleural effusion. As both adult‐onset demodicosis in dogs as well as mycobacterial infection in people have been associated with T‐lymphocyte deficiency, the M kansasii infection in this dog may have been associated with a condition of immune compromise. 相似文献
50.
Masashi Fujinaga Naho Yamagishi Hideki Ogiso Jun Takeuchi Jouji Moriwaki Toyozo Sato 《Journal of General Plant Pathology》2011,77(4):243-247
A new disease was found in Japan, on celery (Apium graveolens var. dulce) having severe chlorotic leaf spot, stunt, and dwarf with leaf curl. A spore suspension from the fungus isolated from affected
plants induced identical symptoms 14 days after plants were sprayed. Identification and molecular characterization showed
that the causal agent is Colletotrichum simmondsii. This report is the first of stunt anthracnose on celery caused by C. simmondsii. We propose the name “stunt anthracnose” for the new disease. Colletotrichum acutatum sensu lato, as reference pathogen of celery anthracnose, should be changed to C. fioriniae based on morphological and molecular characteristics. 相似文献