首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   147篇
  免费   0篇
系统科学   1篇
现状及发展   35篇
研究方法   22篇
综合类   87篇
自然研究   2篇
  2018年   2篇
  2015年   1篇
  2014年   1篇
  2013年   2篇
  2012年   6篇
  2011年   10篇
  2009年   1篇
  2008年   5篇
  2007年   5篇
  2006年   18篇
  2005年   8篇
  2004年   6篇
  2003年   6篇
  2002年   2篇
  2001年   4篇
  2000年   7篇
  1999年   3篇
  1996年   2篇
  1993年   2篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1987年   2篇
  1986年   2篇
  1985年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   3篇
  1979年   5篇
  1976年   3篇
  1975年   2篇
  1974年   3篇
  1973年   1篇
  1972年   1篇
  1971年   2篇
  1970年   8篇
  1969年   4篇
  1968年   3篇
  1967年   5篇
  1966年   2篇
  1965年   2篇
  1964年   1篇
排序方式: 共有147条查询结果,搜索用时 15 毫秒
91.
DNA aneuploidy has been identified as a prognostic factor for epithelial malignancies. Further understanding of the translation of DNA aneuploidy into protein expression will help to define novel biomarkers to improve therapies and prognosis. DNA ploidy was assessed by image cytometry. Comparison of gel-electrophoresis-based protein expression patterns of three diploid and four aneuploid colorectal cancer cell lines detected 64 ploidy-associated proteins. Proteins were identified by mass spectrometry and subjected to Ingenuity Pathway Analysis resulting in two overlapping high-ranked networks maintaining Cellular Assembly and Organization, Cell Cycle, and Cellular Growth and Proliferation. CAPZA1, TXNL1, and HDAC2 were significantly validated by Western blotting in cell lines and the latter two showed expression differences also in clinical samples using a tissue microarray of normal mucosa (n?=?19), diploid (n?=?31), and aneuploid (n?=?47) carcinomas. The results suggest that distinct protein expression patterns, affecting TXNL1 and HDAC2, distinguish aneuploid with poor prognosis from diploid colorectal cancers.  相似文献   
92.
93.
Summary Gastrin has been suggested as a natural secretogogue of the hormone calcitonin. We have found hypercalcitonemia in 55% of patients with pernicious anemia, and the gastrin levels, although usually increased, did not correlate.  相似文献   
94.
95.
96.
Zusammenfassung Im zweiten Abdominalganglion der Indischen Stabheuschrecke (Carausius morosus Br.) wurden 600 ± 50 Neurone, 1000 ± 100 Gliazellen und 500 ± 30 Perineuriumzellen, zusammen etwa 2100 Zellen gezählt. Die Volumina des Ganglions, des Neuropilems und des Zellcortex betrugen etwa: 140 · 10–4 mm3, 75 · 10–4 mm3 und 65 · 10–4 mm3.  相似文献   
97.
Hydrothermal circulation within the sea floor, through lithosphere older than one million years (Myr), is responsible for 30% of the energy released from plate cooling, and for 70% of the global heat flow anomaly (the difference between observed thermal output and that predicted by conductive cooling models). Hydrothermal fluids remove significant amounts of heat from the oceanic lithosphere for plates typically up to about 65 Myr old. But in view of the relatively impermeable sediments that cover most ridge flanks, it has been difficult to explain how these fluids transport heat from the crust to the ocean. Here we present results of swath mapping, heat flow, geochemistry and seismic surveys from the young eastern flank of the Juan de Fuca ridge, which show that isolated basement outcrops penetrating through thick sediments guide hydrothermal discharge and recharge between sites separated by more than 50 km. Our analyses reveal distinct thermal patterns at the sea floor adjacent to recharging and discharging outcrops. We find that such a circulation through basement outcrops can be sustained in a setting of pressure differences and crustal properties as reported in independent observations and modelling studies.  相似文献   
98.
99.
Rifampicin--a new antitrachoma drug   总被引:9,自引:0,他引:9  
Y Becker  Z Zakay-Rones 《Nature》1969,222(5196):851-853
  相似文献   
100.
Neutrinos are elementary particles that carry no electric charge and have little mass. As they interact only weakly with other particles, they can penetrate enormous amounts of matter, and therefore have the potential to directly convey astrophysical information from the edge of the Universe and from deep inside the most cataclysmic high-energy regions. The neutrino's great penetrating power, however, also makes this particle difficult to detect. Underground detectors have observed low-energy neutrinos from the Sun and a nearby supernova, as well as neutrinos generated in the Earth's atmosphere. But the very low fluxes of high-energy neutrinos from cosmic sources can be observed only by much larger, expandable detectors in, for example, deep water or ice. Here we report the detection of upwardly propagating atmospheric neutrinos by the ice-based Antarctic muon and neutrino detector array (AMANDA). These results establish a technology with which to build a kilometre-scale neutrino observatory necessary for astrophysical observations.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号