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51.
颅内原发性中枢神经系统淋巴瘤的MRI研究   总被引:6,自引:1,他引:5  
目的研究颅内原发性中枢神经系统淋巴瘤(PCNSL)的MRI表现特点。资料与方法回顾性分析23例颅内PCNSL的MRI表现。抽取恶性胶质瘤30例、颅内转移瘤30例,共60例归为非PCNSL组作为对照。观察肿瘤部位、分布、信号、形态,并进行统计学分析。结果颅内PCNSL好发于深部脑组织,如胼胝体、丘脑及基底节区,多发病灶多呈区域性分布;肿瘤T2WI多呈等或稍高信号,甚至低信号,扩散加权像(DWI)呈均匀高信号;增强扫描多呈均匀明显强化,肿瘤周围可见“尖突征”。与非PCNSL组之间差异有统计学意义(P〈0.01)。结论颅内PCNSL影像表现多样,但具有一定特征。  相似文献   
52.
Purpose For tissue characterization of the arterial wall, we developed a “phased tracking” method to measure the strain (change in wall thickness) and elasticity of the arterial wall. To improve the accuracy of tissue characterization, we are now attempting to measure other mechanical properties in addition to elasticity. Methods In this study, the change in elasticity during the cardiac diastole was measured with ultrasound by generating a change in internal pressure using remote cyclic actuation. Results From the measured change in elasticity during cardiac diastole, the nonlinear property in the stress–strain relationship of the artery wall was estimated. In basic experiments using a silicone rubber tube and in vivo experiments in human carotid arteries. Conclusion The proposal method enables the noninvasive measurement of the nonlinear mechanical property in addition to the elasticity of the arterial wall.  相似文献   
53.
本文比较了新一代人工牛黄和天然牛黄,人工牛黄对中枢神经系统的影响,实验结果:新一代人工牛黄对小鼠中枢神经系统具有抑制作用,对发热大鼠有一定程度的解热作用,它的药理作用与天然牛黄接近,某些药理作用强于人工牛黄,为新一代人工牛黄代替天然牛黄提供了科学依据.  相似文献   
54.
The development of catecholaminergic neuronal systems in the brain of a teleost, the three-spined stickleback, was studied through embryonic to early larval stages by immunocytochemistry using specific antibodies against dopamine, tyrosine hydroxylase and dopamine β-hydroxylase. By analysing the spatiotemporal patterns of development for the catecholaminergic nuclei, possible homologies with nuclei in amniote brains have been identified.

The noradrenergic neurons in the isthmus region of the rostral rhombencephalon originate in the same manner as the A4–A7 + subcoeruleus group in mammals. Their developmental characteristics show the largest similarities with the subcoeruleus group of birds and mammals, although some features are shared with developing A6 (locus coeruleus) neurons.

Catecholaminergic neurons never appear during development in the ventral mesencephalon of the three-spined stickleback. A group of large dopaminergic neurons that accompany the cerebrospinal fluid (CSF)-contacting neurons follows the border between the hypothalamus and the ventral thalamus into the caudal hypothalamus, where they are continuous with the dopaminergic neurons in the posterior tuberculum. They are thus topologically comparable with the dopaminergic neurons of the zona incerta in mammals.

The dopaminergic CSF-contacting neurons that line the median, lateral and posterior recesses of the third ventricle do not contain tyrosine hydroxylase-immunoreactivity at any developmental stage. This indicates that they take up and accumulate exogenous dopamine or -dihydroxyphenylalanine, and do not synthesize dopamine from tyrosine at any developmental stage. Tyrosine hydroxylase-immunoreactive neurons appear in the pineal organ on the day of hatching (120 h post-fertilization). They were still observed in 240-h-old larvae, but are absent in the pineal organ of adult sticklebacks.

The initial appearance and subsequent differentiation of catecholaminergic neurons in the stickle-back embryo follow essentially the same spatial and temporal pattern as in amphibian, avian and mammalian embryos. This observation supports the hypothesis that morphologically, topologically and chemically similar monoaminergic neurons in different vertebrate classes are homologous.  相似文献   

55.
Reduction mammaplasty by central pedicle flap with short submammary scar   总被引:2,自引:0,他引:2  
Reduction mammaplasty was performed in 30 patients by combining the central pedicle flap method with the short submammary scar (3-S) technique to avoid the common drawbacks of currently popular dermoglandular procedures. Reduction was accomplished by using perforating vascular branches from the pectoralis major muscle and its fascia supplying the nipple and breast parenchyme instead of the subdermal plexus. The central vascular pedicle supplying the nipple-areola complex was preserved. Only the periphery of the breast parenchyme was resected circumferentially, with the exception of the inferolateral portion, so as not to injure the sensory nerve. The remaining breast parenchyme was preserved in an inverted cone shape. The nipple-areola complex was safely transposed with great freedom, and the amount of resection was accurately adjusted for symmetry. No cases of nipple-areola complex sensory change occurred postoperatively, and lactation is possible because of preservation of the lactiferous ducts. The length of postoperative scars was reduced by using the short submammary scar technique. We believe this combined method is ideal in patients requiring resections ranging from 200 to 600 g per breast with good skin elasticity and moderate degree of ptosis.Presented at the Sixth Asian Pacific Congress of the International Confederation for Plastic and Reconstructive Surgery, in Seoul, Korea, October 1993.  相似文献   
56.
Macular oscillatory potentials in humans   总被引:2,自引:0,他引:2  
Studies of the focal macular electroretinogram (ERG) have been made with special reference to oscillatory potentials (OPs) by using a fundus monitoring system in humans. Human macular OPs consist of 3 to 4 wavelets (mean peak interval, approximately 6.5 msec). The distribution of OPs in relation to those in a- and b-waves was studied. The amplitudes of a-waves, b-waves, and OPs of the upper macula were significantly larger than those of the lower macula. The distribution of OPs is relatively sparse in the fovea, becoming more dense than the a- and b-waves from the fovea toward the parafovea, and differing even more toward the perifovea. There was no statistical difference of amplitude in a- and b-waves between nasal and temporal macula. The amplitude of OPs in the temporal macula, however, was significantly larger than in the nasal macula. In some macular diseases, such as diabetic maculopathy, cystoid macular edema, or the convalescent stage of central serous chorioretinopathy, macular OPs were selectively reduced, leaving the a- and b-waves intact. Macular OPs can provide a new aspect of macular function and can be a sensitive indicator to assess that function in macular diseases.  相似文献   
57.
本文作者在572例(1144只眼)近视眼患者拟行角膜放射状切开(RK)手术前,对角膜不同部位厚度进行了测量,对其值作统计学处理,均值及标准差为0.527±0.037mm,标准误为0.002,说明我国95%的近视眼患者中央角膜厚度范围为0.455—0.600mm。提示我国成人各年龄组左、右眼角膜厚度与左、右眼屈光度、性别、眼别无关。强调RK手术前对角膜厚度测量的重要性,但手术预后优劣为多因素所致。  相似文献   
58.
白细胞介素—2新的功能位点及其中枢镇痛作用   总被引:2,自引:0,他引:2  
白细胞介素-2(IL-2)不仅是重要的免疫调节因子,而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标,发现侧脑室注射IL—2能显著提高动物痛阈,并能被纳洛酮所阻断,表示IL-2的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性IL-2实查体仍具有中枢镇痛作用,表明IL—2分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断IL—2的中枢镇痛作用,而不能影响IL—2增殖CTLL-2细胞的作用,提示IL-2发挥镇痛和免疫调节作用可能通过不同的受体途径。IL-2分子中第45位Tyr残基突变为Val后,虽仍保留了免疫活性,但丧失了镇痛功能,表示45位Tyr残基是IL—2发挥中枢镇痛功能的关键残基之一。我们推测IL—2的镇痛功能位点可能在IL—2分子中第45位Tyr残基附近区域。  相似文献   
59.
B超测量皮脂厚度的临床应用   总被引:1,自引:0,他引:1  
目的 :采用B型超声诊断仪进行皮脂厚度测量 ,探讨B超与皮皱厚度卡尺测定结果的相关性。 方法 :选取健康成人 2 19例 ,非疾病死亡 10h之内尸体 11例。用B型超声诊断仪和皮皱厚度卡尺分别测量皮脂厚度。 结果 :B超与皮皱厚度卡尺测量值比较 ,二者差异不显著 (P >0 .0 5 )。 结论 :B型超声诊断仪用于临床评价皮脂厚度是可行的  相似文献   
60.
高血压患者左室舒张功能与左室肥厚的关系及随龄改变   总被引:1,自引:0,他引:1  
为探讨原发性高血压 (以下简称高血压 )患者的左室舒张功能和左室肥厚的关系及其随龄改变 ,抽取 1995年 2月至 2 0 0 2年 7月间门诊高血压患者 4 81例为高血压组 ,以同期体检健康者 2 54 3例为对照组 ,年龄 10~ 80岁 ,并将原发性高血压患者分为 3级 ,每级中按性别分 2组。采用惠普 2 50 0彩色多普勒超声诊断系统检测 2组的室间隔厚度、左室后壁厚度、E/A等指标。使用SPSS软件进行统计学处理分析。结果 :高血压和正常对照组相比E/A显著下降 ,室间隔和左室后壁显著增厚 (P <0 .0 1)。 2个组的E/A均随年龄下降 ,而室间隔厚度随年龄增厚 ,且室间隔厚度和E/A呈显著负偏相关 (P <0 .0 1)。在高血压分级组中 ,Ⅰ~Ⅲ级高血压组中男性的室间隔厚度均厚于女性 (均P <0 .0 1) ,Ⅰ、Ⅱ级高血压组中男性的左室后壁厚度厚于女性 (P <0 .0 5,P <0 .0 1) ,Ⅰ级高血压组中女性的E/A低于男性 (P <0 .0 5)。提示 :左室舒张功能随着年龄的增加而降低 ,而且和高血压左室肥厚呈负偏相关关系 ,性别对其也有一定的影响  相似文献   
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