全文获取类型
收费全文 | 77篇 |
免费 | 0篇 |
专业分类
现状及发展 | 31篇 |
研究方法 | 14篇 |
综合类 | 31篇 |
自然研究 | 1篇 |
出版年
2016年 | 1篇 |
2015年 | 1篇 |
2012年 | 6篇 |
2011年 | 9篇 |
2010年 | 2篇 |
2008年 | 5篇 |
2007年 | 2篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1998年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 6篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有77条查询结果,搜索用时 339 毫秒
31.
Johansson ME Ambort D Pelaseyed T Schütte A Gustafsson JK Ermund A Subramani DB Holmén-Larsson JM Thomsson KA Bergström JH van der Post S Rodriguez-Piñeiro AM Sjövall H Bäckström M Hansson GC 《Cellular and molecular life sciences : CMLS》2011,68(22):3635-3641
In discussions on intestinal protection, the protective capacity of mucus has not been very much considered. The progress in the last years in understanding the molecular nature of mucins, the main building blocks of mucus, has, however, changed this. The intestinal enterocytes have their apical surfaces covered by transmembrane mucins and the whole intestinal surface is further covered by mucus, built around the gel-forming mucin MUC2. The mucus of the small intestine has only one layer, whereas the large intestine has a two-layered mucus where the inner, attached layer has a protective function for the intestine, as it is impermeable to the luminal bacteria. 相似文献
32.
Neuropeptide coexistence in human cortical neurones 总被引:4,自引:0,他引:4
S R Vincent O Johansson T H?kfelt B Meyerson C Sachs R P Elde L Terenius J Kimmel 《Nature》1982,298(5869):65-67
33.
H. Huggel B. Johansson J. Peristiany 《Cellular and molecular life sciences : CMLS》1973,29(8):977-978
Zusammenfassung Die isolierte pulsatile Flughaut-Vene der Fledermäuse zeigt mit dem «Sucrose-gap» eine enge elektro-mechanische Korrelation. Das AP ist oft von einem Schrittmacher-Potential eingeleitet. Solche AP sind äusserst selten bei den Gefässmuskeln.
This study was supported by grants from the Swedish Medical Research Council (28-14 x), the G. and A. Claraz-Schenkung and the Swiss National Scientific Research Funds, and was carried out in the Department of Physiology, University of Lund, Sweden. 相似文献
This study was supported by grants from the Swedish Medical Research Council (28-14 x), the G. and A. Claraz-Schenkung and the Swiss National Scientific Research Funds, and was carried out in the Department of Physiology, University of Lund, Sweden. 相似文献
34.
35.
36.
37.
In autumn the vast majority of the North American population of Eared Grebes ( Podiceps nigricollis ) congregates for several months at Great Salt Lake, Utah, and Mono Lake, California. Because the lakes are so large, it has not been possible to monitor grebe migration with sufficient accuracy to determine when peak numbers are reached. To clarify migration phenology, we analyzed data from 2 isolated wetland areas in southwestern Wyoming where grebes land en route between breeding areas in the interior and Great Salt Lake. Occasional birds, probably nonbreeders or failed breeders, begin moving southward as early as mid-June. Migration of postbreeding birds starts in late July, peaks in late August and September, and is largely completed by the end of October, with very small numbers arriving into November. The pattern of migration and number of birds encountered varied annually, but 95% of the migration was usually completed by 15 October. As a result, censuses at the major staging lake made on or after 15 October but before the grebes depart for wintering areas can be used to study trends in size of the North American population. 相似文献
38.
Long stretches of sea and desert often interrupt the migration routes of small songbirds, whose fat reserves must be restored before these can be crossed as they provide no opportunity for refuelling. To investigate whether magnetic cues might enable inexperienced migratory birds to recognize a region where they need to replenish their body fat, we caught and held thrush nightingales (Luscinia luscinia) in Sweden just before their first migration and exposed them to a magnetic field simulating that at a migratory stopover in northern Egypt, before the Sahara Desert. We found that this magnetic field stimulated the birds to extend their fat-deposition period, indicating that magnetic cues may help small migratory birds to confront large ecological barriers. 相似文献
39.
Central nervous system stem cells in the embryo and adult 总被引:19,自引:0,他引:19
J. Frisén C. B. Johansson C. Lothian U. Lendahl 《Cellular and molecular life sciences : CMLS》1998,54(9):935-945
The central nervous system is generated from neural stem cells during embryonic development. These cells are multipotent
and generate neurons, astrocytes and oligodendrocytes. The last few years it has been found that there are populations of
stem cells also in the adult mammalian brain and spinal cord. In this paper, we review the recent development in the field
of embryonic and adult neural stem cells.
Received 26 March 1998; received after revision 27 April 1998; accepted 27 April 1998 相似文献
40.
提出并验证了一种全数字锁相环(ADPLL)的非线性相位域模型,基于此模型说明了整数型ADPLL进入非线性阶段后,相位差量化器产生的量化误差概率密度分布不再符合现有线性模型条件,线性模型的相位噪声预测公式不再准确.经Matlab与Verilog行为级仿真,验证并解释了整数型ADPLL在非线性阶段呈现的带宽扩展和带内相位噪... 相似文献