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21.
A radiation hybrid map of the rat genome containing 5,255 markers. 总被引:17,自引:0,他引:17
T K Watanabe M T Bihoreau L C McCarthy S L Kiguwa H Hishigaki A Tsuji J Browne Y Yamasaki A Mizoguchi-Miyakita K Oga T Ono S Okuno N Kanemoto E Takahashi K Tomita H Hayashi M Adachi C Webber M Davis S Kiel C Knights A Smith R Critcher J Miller T Thangarajah P J Day J R Hudson Y Irie T Takagi Y Nakamura P N Goodfellow G M Lathrop A Tanigami M R James 《Nature genetics》1999,22(1):27-36
A whole-genome radiation hybrid (RH) panel was used to construct a high-resolution map of the rat genome based on microsatellite and gene markers. These include 3,019 new microsatellite markers described here for the first time and 1,714 microsatellite markers with known genetic locations, allowing comparison and integration of maps from different sources. A robust RH framework map containing 1,030 positions ordered with odds of at least 1,000:1 has been defined as a tool for mapping these markers, and for future RH mapping in the rat. More than 500 genes which have been mapped in mouse and/or human were localized with respect to the rat RH framework, allowing the construction of detailed rat-mouse and rat-human comparative maps and illustrating the power of the RH approach for comparative mapping. 相似文献
22.
Administration of large dose of neostigmine caused very quickly marked myopathic changes at the motor end-plate region. With continued injections, however, some recovery of the structural features did occur suggesting the reconstructive changes in the affected regions. 相似文献
23.
The cleavage of dynorphin and three analogs containing paired basic residues by several proteases was investigated. The cysteine protease of neuroblastoma cells cleaved only the bond between Arg-Arg residues. Submandibular arginylendopeptidase, however, cleaved bonds between both Arg-Arg and Arg-Lys residues, and pancreatic trypsin at the carboxyl sides of both arginine and lysine residues. This shows that the cysteine protease is highly specific for paired arginine residues. 相似文献
24.
T. Watanabe 《Cellular and molecular life sciences : CMLS》1996,52(2):149-154
Pregnant mice received excessive amounts of biotin either subcutaneously (sc) or orally during gestation. There were no differences in the successful pregnancy rates and number of dead or resorbed fetuses between the control and biotin-treated groups. In biotin-treated groups no increased incidence of fetuses with external malformations was clearly demonstrable. However, biotin accumulated in maternal and embryonic organs; especially, the serum biotin level in the biotin-treated dam was 200-fold higher than that in the control dam. There was a difference in biotinidase activity in maternal serum and placenta between the control and biotin-treated groups. It was concluded that excessive amounts of biotin affected the specific activity of biotinidase in pregnant mice, but did not disturb normal reproductive functions and embryonic development. 相似文献
25.
Retinal astrocytes are immigrants from the optic nerve 总被引:15,自引:0,他引:15
The retina in most mammals contains two types of macroglial cells--Müller cells, which span the entire thickness of the retina, and astrocytes, which are mainly confined to the nerve fibre layer. Whereas Müller cells are diffusely distributed in all vertebrate retinae, the presence and distribution of retinal astrocytes correlate with the presence and distribution of retinal blood vessels: retinae that are avascular contain no astrocytes; those that are diffusely vascularized contain diffusely distributed astrocytes; and those that are vascularized in a restricted region contain astrocytes only in the vascularized region. This striking correlation between vascularization and the presence of astrocytes led Stone and Dreher to postulate that retinal astrocytes are immigrants that enter the retina with its vasculature, although others have suggested that they derive from Müller cells. Here we provide strong evidence that astrocytes in the diffusely vascularized rat retina are immigrants from the optic nerve. 相似文献
26.
The effects of all-trans-retinoic acid (RA) (tretinoin) on the craniofacial development of mouse embryos were examined using whole embryo culture. In day 8 embryos cultured for 48 h, embryonic growth was inhibited concentration-dependently by all-trans-RA treatment. Most of the treated embryos exhibited hypoplasia of the primary palatal processes and a reduction in the development of the first visceral arches. In day 10 embryos cultured for 48 h, although embryonic growth was not inhibited at any concentrations of all-trans-RA, median cleft lip (93%), hypoplasia of the primary palatal processes (37%) and limb reduction deformities (48%) occurred commonly. Furthermore, RA treatment greatly reduced the size of the secondary palatal processes. The incorporation of 3H-thymidine in the treated maxillary processes was decreased to 65% of the control value at 1.0 x 10(-7) M all-trans-RA. These findings indicate that all-trans-RA is teratogenic in mouse whole embryo culture. 相似文献
27.
28.
Nakagawa T Shimizu S Watanabe T Yamaguchi O Otsu K Yamagata H Inohara H Kubo T Tsujimoto Y 《Nature》2005,434(7033):652-658
Mitochondria play an important role in energy production, Ca2+ homeostasis and cell death. In recent years, the role of the mitochondria in apoptotic and necrotic cell death has attracted much attention. In apoptosis and necrosis, the mitochondrial permeability transition (mPT), which leads to disruption of the mitochondrial membranes and mitochondrial dysfunction, is considered to be one of the key events, although its exact role in cell death remains elusive. We therefore created mice lacking cyclophilin D (CypD), a protein considered to be involved in the mPT, to analyse its role in cell death. CypD-deficient mice were developmentally normal and showed no apparent anomalies, but CypD-deficient mitochondria did not undergo the cyclosporin A-sensitive mPT. CypD-deficient cells died normally in response to various apoptotic stimuli, but showed resistance to necrotic cell death induced by reactive oxygen species and Ca2+ overload. In addition, CypD-deficient mice showed a high level of resistance to ischaemia/reperfusion-induced cardiac injury. Our results indicate that the CypD-dependent mPT regulates some forms of necrotic death, but not apoptotic death. 相似文献
29.
Tulapurkar AA Suzuki Y Fukushima A Kubota H Maehara H Tsunekawa K Djayaprawira DD Watanabe N Yuasa S 《Nature》2005,438(7066):339-342
There is currently much interest in the development of 'spintronic' devices, in which harnessing the spins of electrons (rather than just their charges) is anticipated to provide new functionalities that go beyond those possible with conventional electronic devices. One widely studied example of an effect that has its roots in the electron's spin degree of freedom is the torque exerted by a spin-polarized electric current on the spin moment of a nanometre-scale magnet. This torque causes the magnetic moment to rotate at potentially useful frequencies. Here we report a very different phenomenon that is also based on the interplay between spin dynamics and spin-dependent transport, and which arises from unusual diode behaviour. We show that the application of a small radio-frequency alternating current to a nanometre-scale magnetic tunnel junction can generate a measurable direct-current (d.c.) voltage across the device when the frequency is resonant with the spin oscillations that arise from the spin-torque effect: at resonance (which can be tuned by an external magnetic field), the structure exhibits different resistance states depending on the direction of the current. This behaviour is markedly different from that of a conventional semiconductor diode, and could form the basis of a nanometre-scale radio-frequency detector in telecommunication circuits. 相似文献
30.