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951.
Brocard JB Rintoul GL Reynolds IJ 《Biology of the cell / under the auspices of the European Cell Biology Organization》2003,95(5):239-242
Mitochondria are a node of integration for intracellular signaling pathways and their morphology changes seem to be tightly associated with their function. New data show that morphology is one of the parameters involved in mitochondria's choice between promoting cell death and protecting cells against general metabolic jeopardy. 相似文献
952.
Li J Hawkins IC Harvey CD Jennings JL Link AJ Patton JG 《Molecular and cellular biology》2003,23(21):7437-7447
SRrp86 is a unique member of the SR protein superfamily containing one RNA recognition motif and two serine-arginine (SR)-rich domains separated by an unusual glutamic acid-lysine (EK)-rich region. Previously, we showed that SRrp86 could regulate alternative splicing by both positively and negatively modulating the activity of other SR proteins and that the unique EK domain could inhibit both constitutive and alternative splicing. These functions were most consistent with the model in which SRrp86 functions by interacting with and thereby modulating the activity of target proteins. To identify the specific proteins that interact with SRrp86, we used a yeast two-hybrid library screen and immunoprecipitation coupled to mass spectrometry. We show that SRrp86 interacts with all of the core SR proteins, as well as a subset of other splicing regulatory proteins, including SAF-B, hnRNP G, YB-1, and p72. In contrast to previous results that showed activation of SRp20 by SRrp86, we now show that SAF-B, hnRNP G, and 9G8 all antagonize the activity of SRrp86. Overall, we conclude that not only does SRrp86 regulate SR protein activity but that it is, in turn, regulated by other splicing factors to control alternative splice site selection. 相似文献
953.
Interleukin-1 (IL-1) has been implicated in neuroimmune responses and has pleiotropic actions in the brain. Compelling evidence
has shown that IL-1 is a major mediator of inflammation and the progression of cell death in response to brain injury and
cerebral ischemia. Its expression is strongly increased in these pathological conditions, and central administration of exogenous
IL-1 significantly exacerbates ischemic brain damage. In contrast, inhibiting IL-1 actions (by intracerebroventricular [icv]
injection of IL-1ra, neutralizing antibody to IL-1 or caspase-1 inhibitor) significantly reduces ischemic brain damage. IL-1
acts by binding to the IL-1 type-1 receptor (IL-1RI), which is to date, the only known functional receptor for IL-1. However,
our recent investigations suggest that IL-1 can act independently of IL-1RI, raising the possibility that additional, as yet
undiscovered, receptor(s) for IL-1 exist in the brain. The recent characterization of putative, new IL-1 ligands and new IL-1
receptor-related molecules leads to the hypothesis that there might be alternative IL-1 signaling pathway(s) in the central
nervous system (CNS). 相似文献
954.
Single-cell transcriptional analysis of neuronal progenitors 总被引:12,自引:0,他引:12
955.
Sasakura Y Shoguchi E Takatori N Wada S Meinertzhagen IA Satou Y Satoh N 《Development genes and evolution》2003,213(5-6):303-313
Cell junctions and the extracellular matrix (ECM) are crucial components in intercellular communication. These systems are thought to have become highly diversified during the course of vertebrate evolution. In the present study, we have examined whether the ancestral chordate already had such vertebrate systems for intercellular communication, for which we have searched the genome of the ascidian Ciona intestinalis. From this molecular perspective, the Ciona genome contains genes that encode protein components of tight junctions, hemidesmosomes and connexin-based gap junctions, as well as of adherens junctions and focal adhesions, but it does not have those for desmosomes. The latter omission is curious, and the ascidian type-I cadherins may represent an ancestral form of the vertebrate type-I cadherins and desmosomal cadherins, while Ci-Plakin may represent an ancestral protein of the vertebrate desmoplakins and plectins. If this is the case, then ascidians may have retained ancestral desmosome-like structures, as suggested by previous electron-microscopic observations. In addition, ECM genes that have been regarded as vertebrate-specific were also found in the Ciona genome. These results suggest that the last common ancestor shared by ascidians and vertebrates, the ancestor of the entire chordate clade, had essentially the same systems of cell junctions as those in extant vertebrates. However, the number of such genes for each family in the Ciona genome is far smaller than that in vertebrate genomes. In vertebrates these ancestral cell junctions appear to have evolved into more diverse, and possibly more complex, forms, compared with those in their urochordate siblings. 相似文献
956.
The important xenoepitope Galalpha(1,3)Gal was thought to be exclusively synthesized by a single alpha(1,3)galactosyltransferase. However, the cloning of the distant family member rat iGb3 synthase, which is also capable of synthesizing Galalpha(1,3)Gal as the glycolipid structure iGb3, challenges the notion that alpha(1,3)galactosyltransferase is the sole Galalpha(1,3)Gal-synthesizing enzyme. We describe the cloning of the rat homolog of alpha(1,3)galactosyltransferase, showing that indeed the rat expresses two distinct alpha(1,3)galactosyltransferases, alpha(1,3)GT and iGb3 synthase. Rat alpha(1,3)galactosyltransferase shows a high amino acid sequence identity with the alpha(1,3)galactosyltransferase of mouse (90%), pig (76%), and ox (75%), in contrast to the low amino acid sequence identity (42%) with iGb3 synthase. The rat alpha(1,3)galactosyltransferase is expressed in heart, brain, spleen, kidney, and liver and has a similar intron/exon structure to the mouse alpha(1,3)galactosyltransferase. Transfection studies show that in contrast to the iGb3 synthase, rat alpha(1,3)galactosyltransferase can synthesize Galalpha(1,3)Gal on glycoproteins but cannot synthesize the glycolipid iGb3, defining two separate glycosylation pathways for the synthesis of Galalpha(1,3)Gal. Furthermore iGb3 synthase was found to be distinct from alpha(1,3)GT with its ability to synthesize poly-alpha-Gal glycolipid structures. 相似文献
957.
Miller WH Manley PJ Cousins RD Erhard KF Heerding DA Kwon C Ross ST Samanen JM Takata DT Uzinskas IN Yuan CC Haltiwanger RC Gress CJ Lark MW Hwang SM James IE Rieman DJ Willette RN Yue TL Azzarano LM Salyers KL Smith BR Ward KW Johanson KO Huffman WF 《Bioorganic & medicinal chemistry letters》2003,13(8):1483-1486
In our continuing efforts to identify small molecule vitronectin receptor antagonists, we have discovered a series of phenylbutyrate derivatives, exemplified by 16, which have good potency and excellent oral bioavailability (approximately 100% in rats). This new series is derived conceptually from opening of the seven-membered ring of SB-265123. 相似文献
958.
Xue CB He X Roderick J Corbett RL Duan JJ Liu RQ Covington MB Qian M Ribadeneira MD Vaddi K Christ DD Newton RC Trzaskos JM Magolda RL Wexler RR Decicco CP 《Bioorganic & medicinal chemistry letters》2003,13(24):4299-4304
Modifications of the lead TACE inhibitor 1 (N-hydroxy-trans-2-[[4-(4-quinolinyloxymethyl)anilinyl]carbonyl]-1-cyclohexanecarboxamide) at the cyclohexyl ring and the quinoline moiety led to the identification of a series of piperidine containing TACE inhibitors with potent activity in the inhibition of TNF-alpha release in the whole blood assay (WBA). The most potent analogue IM491 [N-hydroxy-(5S,6S)-1-methyl-6-[[4-(2-methyl-4-quinolinylmethoxy)anilinyl]carbonyl]-5-piperidinecarboxamide] exhibited an IC(50) value of 20 nM in WBA with excellent selectivity over MMP-1, -2 and -9 and is orally bioavailable with an F value of 43% in beagle dogs. 相似文献
959.
In contrast to the wild-type MoFe protein, neither the alpha-195(Asn) nor the alpha-191(Lys) MoFe protein catalyzed N(2) reduction to NH(3), when complemented with wild-type Fe protein. However, N(2) was bound by the alpha-195(Asn) MoFe protein and inhibited the reduction of both protons and C(2)H(2). The alpha-191(Lys) MoFe protein did not interact with N(2). With the alpha-195(Asn) MoFe protein, the N(2)-induced inhibition of substrate reduction was reversed by removing the N(2). Surprisingly, even though added H(2) also relieved N(2) inhibition of substrate reduction, the alpha-195(Asn) MoFe protein did not catalyze HD formation under a N(2)/D(2) atmosphere. This observation is the first indication that these two reactions have different chemical origins, prompting a revision of the current hypothesis that these two reactions are consequences of the same nitrogenase chemistry. A rationale that accounts for the dichotomy of the two reactions is presented. The two altered MoFe proteins also responded quite differently to azide. It was a poor substrate for both but, in addition, azide was an electron-flux inhibitor with the 195(Asn) MoFe protein. The observed reactivity changes are correlated with likely structural changes caused by the amino acid substitutions and provide important details about the interaction(s) of N(2,) H(2), D(2), and azide with Mo-nitrogenase. 相似文献
960.
Hall IP 《Respiratory research》2000,1(1):6-8
The interleukin-4 (IL-4) signalling cascade has been identified as a pathway potentially important in the development of asthma.
Genetic variants within this signalling pathway might contribute to the risk of developing asthma in a given individual. A
number of polymorphisms have been described within the IL-4 receptor α (IL-4Rα) gene. In addition polymorphism occurs in the
promoter for the IL-4 gene itself. This commentary accompanies a paper by C Oberet al describing the contribution of IL-4Rα polymorphism to susceptibility to asthma and atopy in the Hutterite population and
other outbred populations collected during the collaborative studies on the genetics of asthma (CSGA) programme. 相似文献