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41.
脊柱有关角度的观测及机能意义 总被引:1,自引:0,他引:1
对30具男性成人干燥椎骨的体根角、横突间夹角、弓根间夹角及上关节面与横截面冠状面成角进行了测算,并观察了上关节面的方向、形态及横突与上关节突、椎弓根间的相互位置关系。通过综合分析,讨论了不同节段有关角度的差异与重力线,脊柱曲度大小,方向的关系以及在活动节段中的机能意义。 相似文献
42.
Autoradiography and anterograde horseradish peroxidase transport were used to examine retinocollicular projections in normal hamsters and in animals subjected to ablation of the ipsilateral, posterior neocortex at 1, 3, 6, 10 or 120 days of age. The crossed retinotectal projections of all groups were quite similar. There did, however, appear to be a slight increase in the density of the projection to the lower portion of the stratum griseum superficiale in the neonatally brain-damaged hamsters.The uncrossed pathway, on the other hand, was quite abnormal in the neonatally lesioned animals. In normals, the ipsilateral retinocollicular projection consisted almost entirely of a series of patches along the stratum yriseum superficiale-stratum opticum border in the rostral one-third of the colliculus. Only a few axons from the ipsilateral eye were observed in the caudal two-thirds of the tectum and these could only be visualized when horseradish peroxidase was used as the tracer. In all of the neonatally brain-damaged hamsters both autoradiography and horseradish peroxidase tracing demonstrated that the ipsilateral retina densely innervated the entire rostrocaudal extent of the colliculus.Retrograde tracing experiments demonstrated that the portion of the temporal retina which gave rise to the uncrossed retinocollicular projection in the normal hamsters was also the source of the expanded projection in the neonatally brain-damaged animals; and, further, that the numbers and areal distributions of ipsilaterally projecting retinal and retinocollicular ganglion cells were similar in the two groups.These findings suggest that, at least in the hamster, normal inputs from the two eyes may not be a sufficient condition for the development of the largely complementary pattern of collicular innervation by the two retinae. 相似文献
43.
近年来,用聚合物负载的手性催化剂和手性试剂完成的不对称合成反应主要集中在潜手性酮的不对称还原反应;烯烃的不对称双羟基化反应;烯烃的不对称环氧化反应;不对称Diels-Alder反应和饱和碳原子上的不对称取代反应。就近十年来聚合物负载手性催化剂和手性试剂的合成及应用进行了讨论。 相似文献
44.
采用溶剂萃取-化学处理-柱层析相结合的预处理分离程序、色-质联用和色-红联用结合色谱保留值的定性方法,分析研究了内蒙东胜煤快速加氢热解焦油的化学成分和结构,推测鉴定出200多种化合物,并对具有代表性的19种多环芳烃进行了定量分析,讨论了快速加氢热解焦油化学成分的结构特征。 相似文献
45.
目的 建立手性包甲素类似物绝对构型的简便方法。方法 以外消旋6β-羟基莨菪烷-3-酮为原料,通过拆分、酰化和还原制备手性包甲素类似物。结果 合成了手性包甲素类似物,通过物理常数、光谱数据鉴定其结构并与已知构型的化合物Is进行化学关联确定其绝对构型。结论 本文建立的方法可用于确定某些活性手性包甲素类似物的绝对构型,从而有助于此类化合物构效关系的进一步研究。 相似文献
46.
柱切换HPLC法测定腹水中左旋氧氟沙星的含量 总被引:1,自引:0,他引:1
目的:应用柱切换HPLC技术直接测定腹水中左旋氧氟沙得含量。方法:采用磷酸二氢钾缓冲溶液(PH2.2)-0.05mol/L四丁溴化化铵(100:4)为预处理流动相,经μBondapak C18柱预处理后,切换到Irregular_HC18分析柱,以甲醇-磷权二氢钾缓冲溶液(PH2.2)-0.05mol/L四丁基溴化铵(30:70:4)为分析流动相进行分离测定,紫外线皮长为294nm。结果:左旋氧氟 相似文献
47.
NMDA受体与NOS在大鼠脊髓中间外侧柱的定位和生后发育 总被引:7,自引:3,他引:4
目的 探讨N-甲基-天冬氨酸受体(NMDAR1和NMDAR2A/B亚基)、一氧化氮合酶(NOS)及还原型辅酶Ⅱ硫辛酰胺脱氢酶(NADPH-d)活性在大鼠脊髓中间外侧柱(IML)的定位与生后发育特征。方法 在甲醛固定的脊髓切片上,进行ABC法免疫染色和NADPH-d组织化学反应与半定量分析。结果 MMDAR1,NMDAR2A/B,NOS I和NADPH-d反应产物丰富地分布于IML,主要定位于神经元胞体、树突和轴突样纤维终末。在生后早期发育中它们具有明显的动态变化,生后7d(P7)有微弱或中等的表达,随后逐渐上调,P21或P28达到高峰,然后保持于此水平于成体动物。结论 NMDA受体-NO通路可能是脊髓交感节前神经元一条重要的细胞内信号途径,并参与神经元生后发育成熟的调控过程。 相似文献
48.
二氢嘧啶酶的分离纯化与性质研究 总被引:3,自引:0,他引:3
二氢嘧啶酶产生菌Pseudomonasputida 980 1经过超声波粉碎及分级盐析 ,DEAE 纤维素和羟基磷灰石柱层析 ,SephadexG 2 0 0凝胶过滤得到纯化 2 49倍的酶液。SDS PAGE显示为单带 ,单体分子量为 380 0 0 ,SephadexG 2 0 0凝胶过滤测得分子量为 15 6 0 0 0。二氢嘧啶酶对苯海因的km 为 2 .39× 10 -2 mol/L ,其最适 pH和最适温度分别是 8.5~ 8.7和 34℃~ 35℃。 1mmol/L的EDTA和 β 巯基乙醇对酶活力有强烈的抑制作用。 相似文献
49.
Werner Neupert Roland Brugger Christian Euchenhofer Kay Brune Gerd Geisslinger 《British journal of pharmacology》1997,122(3):487-492
- Ibuprofen enantiomers and their respective coenzyme A thioesters were tested in human platelets and blood monocytes to determine their selectivity and potency as inhibitors of cyclo-oxygenase activity of prostaglandin endoperoxide synthase-1 (PGHS-1) and PGHS-2.
- Human blood from volunteers was drawn and allowed to clot at 37°C for 1 h in the presence of increasing concentrations of the test compounds (R-ibuprofen, S-ibuprofen, R-ibuprofenoyl-CoA, S-ibuprofenoyl-CoA, NS-398). Immunoreactive (ir) thromboxane B2 (TXB2) concentrations in serum were determined by a specific EIA assay as an index of the cyclo-oxygenase activity of platelet PGHS-1.
- Heparin-treated blood from the same donors was incubated at 37°C for 24 h with the same concentrations of the test compounds in the presence of lipopolysaccharide (LPS, 10 μg ml−1). The contribution of PGHS-1 was suppressed by pretreatment of the volunteers with aspirin (500 mg; 48 h before venepuncture). As a measure of LPS induced PGHS-2 activity immunoreactive prostaglandin E2 (irPGE2) plasma concentrations were determined by a specific EIA assay.
- S-ibuprofen inhibited the activity of PGHS-1 (IC50 2.1 μM) and PGHS-2 (IC50 1.6 μM) equally. R-ibuprofen inhibited PGHS-1 (IC50 34.9) less potently than S-ibuprofen and showed no inhibition of PGHS-2 up to 250 μM. By contrast R-ibuprofenoyl-CoA thioester inhibited PGE2 production from LPS-stimulated monocytes almost two orders of magnitude more potently than the generation of TXB2 (IC50 5.6 vs 219 μM).
- Western blotting of PGHS-2 after LPS induction of blood monocytes showed a concentration-dependent inhibition of PGHS-2 protein expression by ibuprofenoyl-CoA thioesters.
- These data confirm that S-ibuprofen represents the active entity in the racemate with respect to cyclo-oxygenase activity. More importantly the data suggest a contribution of the R-enantiomer to therapeutic effects not only by chiral inversion to S-ibuprofen but also via inhibition of induction of PGHS-2 mediated by R-ibuprofenoyl-CoA thioester.
- The data may explain why racemic ibuprofen is ranked as one of the safest non-steroidal anti-inflammatory drugs (NSAIDs) so far determined in epidemiological studies.
50.
Serotonin (5-HT) nerve terminals innervate sympathetic preganglionic neurons of the intermediolateral cell column (IML); however, neither the depolarization-induced release of 5-HT nor the presence of presynaptic modulatory autoreceptors have been directly studied in this system. We used in vitro superfusion of the microdissected intermediate area (including the intermediolateral cell column, intercalated nucleus, and central autonomic nucleus) of the rat thoracic spinal cord to measure basal and stimulated release of preloaded [3H]5-HT. Elevated K+ evoked a concentration- and Ca2+ dependent release of [3H]5-HT. Exogenous 5-HT and the 5-HT1B agonist, CGS-12066B, both decreased the K+-stimulated release of [3H]5-HT. A 5-HT1B antagonist (methiothepin) blocked the 5-HT- and the CGS-12066B-induced inhibition of K+-evoked release of [3H]5-HT. A 5-HT1A antagonist (NAN-190) did not alter the inhibitory actions of exogenous 5-HT. Moreover, a 5-HT1A agonist (8-OH-DPAT), a 5-HT2A/2C agonist [(+/-)-DOI hydrochloride], and a 5-HT3 agonist (2-methyl-5-HT) did not alter the K+ evoked release of [3H]5-HT. These data demonstrate that 5-HT is released from the intermediate area of the rat thoracic spinal cord. The 5-HT receptor subtype involved in the inhibition of the evoked release of [3H]5-HT is of the 5-HT1B subtype. These findings may help clarify the complex role of 5-HT in spinal regulation of the sympathetic nervous system. © 1994 Wiley-Liss, Inc 1 This article is US Government work and, as such, is in the public domain in the United States of America. 相似文献