排序方式: 共有29条查询结果,搜索用时 125 毫秒
21.
S Shiozawa K Shiozawa S Shimizu Y Tanaka I Morimoto Y Kuroki R Yoshihara T Fujita 《Experientia》1989,45(8):764-765
A sensitive radioimmunoassay showed that circulating alpha-interferon in the plasma of healthy individuals was low in children and reached the highest level in the young adult, then declined gradually with age. Circulating alpha-interferon was 0.201 +/- 0.059 ng/ml in males (n = 19) and 0.184 +/- 0.076 ng/ml in females (n = 14) at ages 30-39 years old. It was noted that circulating alpha-interferon was maintained up to a certain level even in elderly individuals. 相似文献
22.
Lambrechts D Storkebaum E Morimoto M Del-Favero J Desmet F Marklund SL Wyns S Thijs V Andersson J van Marion I Al-Chalabi A Bornes S Musson R Hansen V Beckman L Adolfsson R Pall HS Prats H Vermeire S Rutgeerts P Katayama S Awata T Leigh N Lang-Lazdunski L Dewerchin M Shaw C Moons L Vlietinck R Morrison KE Robberecht W Van Broeckhoven C Collen D Andersen PM Carmeliet P 《Nature genetics》2003,34(4):383-394
23.
Seki K Hirahara M Hoshino M Terasawa T Elphic RC Saito Y Mukai T Hayakawa H Kojima H Matsumoto H 《Nature》2003,422(6932):589-592
Most visible matter in the Universe exists as plasma. How this plasma is heated, and especially how the initial non-equilibrium plasma distributions relax to thermal equilibrium (as predicted by Maxwell-Boltzman statistics), is a fundamental question in studies of astrophysical and laboratory plasmas. Astrophysical plasmas are often so tenuous that binary collisions can be ignored, and it is not clear how thermal equilibrium develops for these 'collisionless' plasmas. One example of a collisionless plasma is the Earth's plasma sheet, where thermalized hot plasma with ion temperatures of about 5 x 10(7) K has been observed. Here we report direct observations of a plasma distribution function during a solar eclipse, revealing cold ions in the Earth's plasma sheet in coexistence with thermalized hot ions. This cold component cannot be detected by plasma sensors on satellites that are positively charged in sunlight, but our observations in the Earth's shadow show that the density of the cold ions is comparable to that of hot ions. This high density is difficult to explain within existing theories, as it requires a mechanism that permits half of the source plasma to remain cold upon entry into the hot turbulent plasma sheet. 相似文献
24.
H. Itoh T. Morimoto K. Kawashima I. Chibata 《Cellular and molecular life sciences : CMLS》1973,29(3):271-271
Zusammenfassung Zur Biosynthese von Eritadenin in einem Speisepil Shiitake wurde 4-(6-amino-9H-purine-9-yl)-3-hydroxybuttersäure als ein Zwischenprodukt isoliert und identifiziert. 相似文献
25.
ACTH response induced by interleukin-1 is mediated by CRF secretion stimulated by hypothalamic PGE 总被引:3,自引:0,他引:3
We investigated whether hypothalamic prostaglandin E2 (PGE2) and corticotropin releasing factor (CRF) are responsible for the development of the adrenocorticotropic hormone (ACTH) response induced by interleukin-1 alpha (IL-1 alpha). The present results show that ACTH responses induced by intravenous injection of IL-1 alpha were suppressed by systemic pretreatment with indomethacin and that intrahypothalamic injection of PGE2 stimulates the secretion of ACTH. Furthermore, systemic pretreatment with anti-CRF antibody significantly suppressed the ACTH response induced by intrahypothalamic injection of PGE2. These data suggest that the ACTH response induced by IL-1 is mediated by CRF secretion stimulated by hypothalamic PGE2. 相似文献
26.
The Ontology registry system is developed to collect, manage, and compare ontological information for integrating global observation data. Data sharing and data service such as support of metadata deign, structuring of data contents, support of text mining are applied for better use of data as data interoperability. Semantic network dictionary and gazetteers are constructed as a trans-disciplinary dictionary. Ontological information is added to the system by digitalizing text based dictionaries, developing "knowledge writing tool" for experts, and extracting semantic relations from authoritative documents with natural language processing technique. The system is developed to collect lexicographic ontology and geographic ontology. 相似文献
27.
The Mesp2 transcription factor establishes segmental borders by suppressing Notch activity 总被引:1,自引:0,他引:1
The serially segmented (metameric) structures of vertebrates are based on somites that are periodically formed during embryogenesis. A 'clock and wavefront' model has been proposed to explain the underlying mechanism of somite formation, in which the periodicity is generated by oscillation of Notch components (the clock) in the posterior pre-somitic mesoderm (PSM). This temporal periodicity is then translated into the segmental units in the 'wavefront'. The wavefront is thought to exist in the anterior PSM and progress backwards at a constant rate; however, there has been no direct evidence as to whether the levels of Notch activity really oscillate and how such oscillation is translated into a segmental pattern in the anterior PSM. Here, we have visualized endogenous levels of Notch1 activity in mice, showing that it oscillates in the posterior PSM but is arrested in the anterior PSM. Somite boundaries formed at the interface between Notch1-activated and -repressed domains. Genetic and biochemical studies indicate that this interface is generated by suppression of Notch activity by mesoderm posterior 2 (Mesp2) through induction of the lunatic fringe gene (Lfng). We propose that the oscillation of Notch activity is arrested and translated in the wavefront by Mesp2. 相似文献
28.
A novel epitope of the LFA-1 antigen which can distinguish killer effector and suppressor cells in human CD8 cells 总被引:1,自引:0,他引:1
The CD4 subset of cells displays helper/inducer activity and recognizes class II antigens of the major histocompatibility complex (MHC), while the CD8 subset recognizes class I MHC antigens and exhibits cytotoxic or suppressor function. Considerable functional as well as corresponding phenotypic heterogeneity exists within the two major T cell subsets. Although the CD8+ population contains pre-cytotoxic, cytotoxic, pre-suppressor and suppressor effector T cells, these distinctions still rest largely on the use of functional assays. Attempts have been made to define the CD8+ precursor of the killer cell with new monoclonal antibodies. But more precise phenotypic distinctions between the functional subpopulations within CD8+ cells will be needed. We have now developed a monoclonal antibody, anti-S6F1 which can distinguish killer effector and suppressor effector cells in CD8 lymphocyte populations. The cell-surface structure defined by this antibody comprises two glycoproteins with relative molecular mass (Mr) 180K and 95K respectively. Also sequential immunoprecipitation studies and two dimensional gel electrophoresis indicate that anti-S6F1 recognizes a novel epitope on the LFA-1 antigen. 相似文献
29.
利用3S技术对图们江下游地区的湿地系统进行了分类.以Spot卫星影像为信息提取的数据源,采用监督分类和人工分类相结合的方法,把该地区的湿地划分为5个系统、8个子系统和12个类型.通过对分类结果的比较分析发现,虽然图们江下游地区湿地的面积比较大,但是主要以人工湿地为主,自然湿地所占比重低且湿地景观比较破碎,湿地生态系统脆弱. 相似文献