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41.
42.
S Kh Khaduev O S Zhukova Ia V Dobrynin K Soda T T Berezov 《Biulleten' eksperimental'no? biologii i meditsiny》1986,101(5):603-604
L-lysine-alpha-oxidase, a new fungal enzyme catalyzing oxidative deamination of L-lysine, exerts an inhibitory effect on DNA, RNA and protein synthesis in human cells of carcinoma ovarius (CaOv) in vitro. 相似文献
43.
L J Petterborg M K Vaughan L Y Johnson T H Champney R J Reiter 《Comparative biochemistry and physiology. A, Comparative physiology》1984,78(1):31-34
Exposure of male Syrian hamsters (Mesocricetus auratus) for 10 weeks to short photoperiod (SP) providing 10 hr light: 14 hr darkness (10:14 LD) produced a significant reduction in the weights of the reproductive organs, plasma thyroxine (T4) levels and free T4 index (FT4I) compared to the values of animals exposed to long photoperiod (LP, 14:10 LD). C57bl male house mice (Mus musculus) kept in SP (10:14 LD) had reproductive organ weights equivalent to those of mice kept in long days (14:10 LD) and lower T3 uptake (T3U) values. Male gerbils (Meriones unguiculatus) exposed to 13 weeks of SP (10:14 LD) had lower body weights, testes and seminal vesicle weights and higher T3U values compared to LP (14:10 LD) controls. However, no effect was seen on plasma T4 and triiodothyronine (T3) values nor the FT4I and free T3 index (FT3I). White-footed male mice (Peromyscus leucopus) exposed to SP (8:16 LD) had significantly lower testes and seminal vesicle weights while plasma T4 and T3 levels were unaffected. Snell strain house mice (Mus musculus) exposed to SP (8:16 LD) had normal reproductive organ weights compared to the values of LP-exposed (16:8 LD) control animals. However, there was a significant depression in T3 and in the FT3I in the SP animals. 相似文献
44.
45.
Airway area by acoustic reflections measured at the mouth 总被引:5,自引:0,他引:5
Fredberg J. J.; Wohl M. E.; Glass G. M.; Dorkin H. L. 《Journal of applied physiology》1980,48(5):749-758
46.
Plant somatic cells have the capability to switch their cell fates from differentiated to undifferentiated status under proper
culture conditions, which is designated as totipotency. As a result, plant cells can easily regenerate new tissues or organs
from a wide variety of explants. However, the mechanism by which plant cells have such remarkable regeneration ability is
still largely unknown. In this study, we used a set of meristem-specific marker genes to analyze the patterns of stem cell
differentiation in the processes of somatic embryogenesis as well as shoot or root organogenesis in vitro. Our studies furnish preliminary and important information on the patterns of the de novo stem cell differentiation during various types of in vitro organogenesis. 相似文献
47.
Claudia Raedig Carsten F. Dormann Anke Hildebrandt Sven Lautenbach 《Biodiversity and Conservation》2010,19(6):1523-1546
Monographic data rely on specimens deposited in herbaria and museums, which have been thoroughly revised by experts. However,
monographic data have been rarely used to map species richness at large scale, mainly because of the difficulties caused by
spatially heterogeneous sampling effort. In this paper we estimate patterns of species richness and narrow endemism, based
on monographic data of 4,055 Neotropical angiosperm species. We propose a geometric interpolation method to derive species
ranges at a 1° grid resolution. To this we apply an inverse distance-weighted summation scheme to derive maps of species richness
and endemism. In the latter we also adjust for heterogeneous sampling effort. Finally, we test the robustness of the interpolated
species ranges and derived species richness by applying the same method but using a leave-one-out-cross-validation (LOOCV).
The derived map shows four distinct regions of elevated species richness: (1) Central America, (2) the Northern Andes, (3)
Amazonia and (4) the Brazilian Atlantic coast (‘Mata Atlantica’). The region with the highest estimated species richness is
Amazonia, with Central America following closely behind. Centers of narrow endemism are located over the entire Neotropics,
several of them coinciding with regions of elevated species richness. Sampling effort has a minor influence on the interpolation
of overall species richness, but it substantially influences the estimation of regions of narrow endemism. Thus, in order
to improve maps of narrow endemism and resulting conservation efforts, more collection and identification activity is required. 相似文献
48.
P C de Visser N M A J Kriek P A V van Hooft A Van Schepdael D V Filippov G A van der Marel H S Overkleeft J H van Boom D Noort 《The journal of peptide research》2003,61(6):298-306
As part of a program towards the development of novel antibiotics, a convenient method for solid-phase synthesis of the cyclic cationic peptide polymyxin B1 and analogues thereof is described. The methodology, based on cleavage-by-cyclization using Kenner's safety-catch linker, yields crude products with purities ranging from 37-67%. Antibacterial assays revealed that analogues 23-26, in which the (S)-6-methyloctanoic acid moiety is replaced with shorter acyl chains, exhibit distinct antimicrobial activity. The results suggest that the length of the acyl chain is rather critical for antimicrobial activity. On the other hand, substitution of the hydrophobic ring-segment D-Phe-6/Leu-7 in polymyxin B1 with dipeptide mimics (i.e. analogues 27-33) resulted in almost complete loss of antimicrobial activity. 相似文献
49.
50.
Localization of cathepsin D in rat liver. Immunocytochemical study using post-embedding immunoenzyme and protein A-gold techniques 总被引:1,自引:0,他引:1
Light and electron microscopic localization of cathepsin D in rat liver was investigated by post-embedding immunoenzyme and protein A-gold techniques. By light microscopy, cytoplasmic granules of parenchymal cells and Kupffer cells were stained for cathepsin D. Weak staining was also noted in sinusoidal endothelial cells. In the parenchymal cells many of positive granules located around bile canaliculi. In the Kupffer cells and the endothelial cells, diffuse staining was noted in the cytoplasm in addition to granular staining. By electron microscopy, gold particles representing the antigenic sites for cathepsin D were seen in typical secondary lysosomes and some multivesicular bodies of the parenchymal cells and Kupffer cells. The lysosomes of the endothelial cells and fat-storing cells were weakly labeled. Quantitative analysis of the labeling density in the lysosomes of these three types of cells demonstrated that the lysosomes of parenchymal cells and Kupffer cells are main containers of cathepsin D in rat liver. The results suggest that cathepsin D functions in the intracellular digestive system of parenchymal cells and Kupffer cells but not so much in that of the endothelial cells. 相似文献