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61.
Grünert U 《Clinical and experimental pharmacology & physiology》1999,26(11):941-944
1. GABA and glycine mediate synaptic inhibition via specific neurotransmitter receptors. Molecular cloning studies have shown that there is a great diversity of receptors for these two neurotransmitters. In the present paper, the distribution of GABAA and glycine receptors in the mammalian retina is reviewed. 2. In situ hybridization, immunocytochemistry with subunit-specific antibodies and single cell injection were used to analyse the localization of receptor subunits. Specific subunits are expressed in characteristic strata of the inner plexi-form layer, suggesting that different functional circuits involve specific subtypes of neurotransmitter receptors. 3. Different cell types express different combinations of receptor subunits and an individual neuron can express several receptor isoforms at distinct post-synaptic sites. 相似文献
62.
Acid and base catalyzed intramolecular cyclizations ofN-benzoylthioureidoacetal, containing four functional groups adjacent to thiourea such as benzocarbamoyl, acetal, thioure and
amide, were investigated. The condensation reaction ofN-benzoyl thiocarbamoylglycine amide in the presence of 10% aqueous NaOH provided 1-(2,2-dimethoxy)ethyl-imidazolidine-2-thione
exclusively. In the presence of pyridine, it was transformed to 2-thiohydantoin.N-Benzoyl thiocarbamoyl glycine amide was completely transformed to an iminothiazolidine exclusively in the presence of Lewis
acid such as borontrifluoride etherate or trimethylsilyl iodide. 1-(2,2-Dimethoxy)ethyl-imidazolidine-2-thione was transformed
to imidazole[2,1-b]thiazole and pyrazino[5,1-a]imidazole in the presence of BF3.Et2O and formic acid, respectively. 相似文献
63.
Identification of glycinergic synapses in the cochlear nucleus through immunocytochemical localization of the postsynaptic receptor 总被引:9,自引:0,他引:9
Richard A. Altschuler Heinrich Betz Marianne H. Parakkal Karen A. Reeks Robert J. Wenthold 《Brain research》1986,369(1-2):316-320
The distribution and morphology of glycinergic synapses in the cochlear nucleus were investigated using monoclonal antibodies against the glycine receptor. Glycine receptor immunoreactivity was seen on somas and proximal processes of most cells in all divisions of the cochlear nucleus; distribution of label in neuropil was denser in the dorsal cochlear nucleus and granule cell cap than in the ventral cochlear nucleus. At the ultrastructural level, glycine receptor immunoreactivity was specifically distributed postsynaptically to terminals that contained flattened vesicles in the guinea pig anteroventral cochlear nucleus. These studies show that the immunocytochemical localization of the glycine receptor can provide a means of identifying and characterizing glycinergic synapses throughout the central nervous system. 相似文献
64.
Kenneth M. Johnson Lawrence D. Snell Aida I. Sacaan Susan M. Jones 《Drug development research》1989,17(4):281-297
The ion channel operated by N-methyl-D-aspartate (NMDA) receptor agonists is modified by several positive and negative effectors. A variety of chemical structures are known to antagonize the effects of NMDA agonists by preferentially binding with high affinity to the open state of the ion channel. Binding of two of these noncompetitive antagonists has been study extensively in recent months as a probe of NMDA receptor function. It has been found that NMDA agonists and antagonists increase and decrease, respectively, the binding of 3H-TCP or 3H-MK-801 by altering the affinity of the putative phencyclidine (PCP) receptor localized within the ion channel. This affinity change is presumed to be correlated with the conformational change associated with channel opening. This model is also discussed in relationship to one in which binding is increased under nonequilibrium conditions because of a simple increased accessibility to the channel binding site. The modulatory effects of glycine, other amino acids, certain polyamines, and divalent cations on 3H-TCP and/or 3H-MK-801 binding are discussed in relation to their effects on NMDA function in more intact, physiological preparations. It is concluded that the complexity of NMDA receptor regulation provides many possibilities for pharmacological intervention, and that the use of noncompetitive antagonists to probe NMDA receptor function could play a key role in drug development. 相似文献
65.
P-L Chau 《British journal of pharmacology》2010,161(2):288-307
This paper provides new insights of how general anaesthetic research should be carried out in the future by an analysis of what we know, what we do not know and what we would like to know. I describe previous hypotheses on the mechanism of action of general anaesthetics (GAs) involving membranes and protein receptors. I provide the reasons why the GABA type A receptor, the NMDA receptor and the glycine receptor are strong candidates for the sites of action of GAs. I follow with a review on attempts to provide a mechanism of action, and how future research should be conducted with the help of physical and chemical methods. 相似文献
66.
Glycine neurons in the brain and spinal cord. Antibody production and immunocytochemical localization 总被引:2,自引:0,他引:2
Antibodies were raised against glycine and they were specific for immunocytochemistry. Obtained from rabbits immunized with glycine conjugated to glutaryled protein-carriers, antisera were then purified by adsorption on the various glutaraldehyde-conjugated protein-carriers. Using a modified ELISA method, their specificity was determined in competition experiments between conjugated glycine and either non-conjugated glycine or other conjugated amino acids or derivatives, preincubated with anti-glycine antibodies. Calculated at half-displacement, the resulting cross-reactivity ratios showed conjugated glycine to be the best recognized compound. By revealing the presence of the majority of the glycine-containing cell bodies in the brainstem and spinal cord, immunocytochemical applications of glycine antibodies confirmed their use as specific tools for a better understanding of the role of glycine in the central nervous system. 相似文献
67.
YOSHITANE KOJIMA YOUKO IKEDA ETSUKO KUMATA JOJI MARUO AKIHIRO OKAMOTO KEN HIROTSU KOZO SHIBATA AKIO OHSUKA 《Chemical biology & drug design》1991,37(6):468-475
The solution conformations of novel dipeptides, methyl (2S, 3′S)-3-methyl-2-(2′-oxo-3′-isopropyl-1′-piperazinyl)-butanoate (EVV-OCH3), methyl (2S, 3′S)-3-phenyl-2-(2′-oxo-3′-benzyl-1′-piperazinyl) propionate (EFF-OCH3), and their derivatives (Boc-Gly-EW-OH, Boc-Gly-EVV-Gly-OH, and Boc-Gly-EFF-OH), were studied by ‘H NMR measurements and molecular mechanics calculations (1). The molecular structures of Boc-Gly-EVV-OH, Boc-Gly-EFF-OH, and the hydrochloride of EVV-OCH3 were determined by X-ray analyses. The conformations of the piperazinone rings and the side chains of these oligopeptides were clarified. 相似文献
68.
Zongjun Shao Amit Kamboj Christopher M. Anderson 《Journal of neuroscience research》2009,87(11):2520-2530
D‐serine is an endogenous coagonist of N‐methyl‐D‐aspartate (NMDA) receptors that plays an important role in synaptic function, neuronal development, and excitotoxicity. Mechanisms of D‐serine transport are important in regulation of extracellular D‐serine concentration and therefore of these critical processes. D‐serine can be transported with low affinity through the Na+‐dependent amino acid transporter termed ASCT2, whereas high‐affinity D‐serine uptake has been reported through the Na+‐independent transporter termed asc‐1. We investigated immunoreactivity for ASCT2 and asc‐1 and D‐serine transport kinetics in cultured cortical neurons and astrocytes to gain insight into how D‐serine transporters regulate CNS D‐serine levels. Both neurons and astrocytes exhibited low‐affinity Na+‐dependent D‐serine uptake (KT > 1 mM) with broad substrate selectivity that was consistent with uptake through ASCT2. Both neurons and astrocytes also stained positively for ASCT2 in immunocytochemistry studies. Neurons but not astrocytes stained positively for the high‐affinity D‐serine transporter asc‐1, but no evidence of functional asc‐1 could be detected in neurons with conditions that produced such activity in cortical synaptosomes. These data support ASCT2 function in both neuron and astrocyte cultures and identify a discrepancy between observed asc‐1 immunoreactivity and lack of functional asc‐1 activity in neuron cultures. Together these findings further our knowledge of the processes that govern D‐serine regulation. © 2009 Wiley‐Liss, Inc. 相似文献
69.
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