首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   35854篇
  免费   3073篇
  国内免费   1879篇
耳鼻咽喉   578篇
儿科学   514篇
妇产科学   821篇
基础医学   4198篇
口腔科学   570篇
临床医学   4222篇
内科学   6288篇
皮肤病学   813篇
神经病学   1920篇
特种医学   1274篇
外国民族医学   17篇
外科学   3626篇
综合类   4289篇
现状与发展   4篇
一般理论   7篇
预防医学   2341篇
眼科学   799篇
药学   3670篇
  23篇
中国医学   1655篇
肿瘤学   3177篇
  2024年   83篇
  2023年   488篇
  2022年   1150篇
  2021年   1532篇
  2020年   1114篇
  2019年   1168篇
  2018年   1287篇
  2017年   1096篇
  2016年   1047篇
  2015年   1553篇
  2014年   1906篇
  2013年   1895篇
  2012年   2666篇
  2011年   2806篇
  2010年   1804篇
  2009年   1341篇
  2008年   1931篇
  2007年   1863篇
  2006年   1866篇
  2005年   1831篇
  2004年   1330篇
  2003年   1271篇
  2002年   1092篇
  2001年   903篇
  2000年   830篇
  1999年   755篇
  1998年   474篇
  1997年   421篇
  1996年   340篇
  1995年   311篇
  1994年   284篇
  1993年   204篇
  1992年   333篇
  1991年   290篇
  1990年   224篇
  1989年   187篇
  1988年   206篇
  1987年   165篇
  1986年   132篇
  1985年   123篇
  1984年   87篇
  1983年   48篇
  1982年   32篇
  1981年   39篇
  1980年   27篇
  1979年   33篇
  1978年   29篇
  1977年   27篇
  1976年   23篇
  1973年   24篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Almost 90% of primary acute pericarditis are idiopathic. Between specifics forms, a very low percentage of cases are due to chronic rheumatic diseases. A case of adult Still's disease (juvenile chronic rheumatoid arthritis) with acute pericarditis being the first clinical manifestation (besides fever and general syndrome) is presented. Therapy with oral prednisone was rapidly effective, and pericardial effusion resolved after 3 weeks of treatment, as echocardiography showed.  相似文献   
12.
13.
We study 40 patients, 55 +/- 7 years old with acute myocardial infarction treated early by thrombolytic therapy (20 STK and 20 rt-PA). All patients were angiographically studied in the following conditions: 1) baseline, before initiating therapy. 2) Three hours after treatment. 3) Twenty four hours later. 4) Before discharge. The infarct related artery was patent 24 hours after treatment in 31 patients (78%); five of them were patent before treatment, and we observed an early reperfusion in 20 patients (57%) and late reperfusion in 6 patients (17%). The number of patients with angiographic evidence of intraluminal thrombus decreased progressively through conditions while the grade TIMI of coronary perfusion increased in the absence of reocclusion. Final regional wall motion of infarct related myocardial zones and their degree of recovery were significantly higher in recanalized patients, as compared with non-reperfused patients. Similarly, left ventricular functional recovery was higher in patients with antegrade of collateral flow to the infarct area, as compared with totally occluded patients.  相似文献   
14.
咯血是肺结核最常见的并发症之一,多见于初、复治的Ⅲ型肺结核病人,尤其是有空洞形成者。笔者近10年来采用云南白药(或云南白药胶囊)与维生素K4联合治疗初、复治肺结核引起少量咯血的病人,收到了较理想的效果,报告如下。  相似文献   
15.
Effects of stimulation of brainstem sites on hemodynamics and plasma catecholamine levels were assessed in cats under chloralose-urethane anesthesia. Pressor areas of the dorsal medulla (DM) and ventrolateral medulla (VLM) and the depressor area of the paramedian reticular nucleus (PRN) were stimulated electrically using a monopolar electrode, or chemically using sodium glutamate microinjection. Plasma levels of norepinephrine (NE) and epinephrine (EPI) were measured in caval blood above the adrenal veins. Electrical stimulation of the DM and VLM produced increases in blood pressure and in plasma NE and EPI levels that were enhanced after acute vagotomies. The NE and EPI responses were attenuated after acute, bilateral adrenalectomies, confirming augmented adrenomedullary secretion, whereas the pressor responses were intact. Injection of sodium glutamate into the same pressor regions of the DM or VLM also produced pressor responses and elevated plasma catecholamine levels, indicating that the responses resulted from activation of neuronal perikarya. Stimulation of the PRN attenuated pressor and catecholamine responses during stimulation of the DM and VLM. The results indicate that pressor responses during stimulation of the DM and VLM are due at least partly to activation of perikarya in these regions, are associated with but not dependent on adrenomedullary activation, and are enhanced after vagotomy; and that neurons of the PRN exert inhibitory modulation of the pressor and adrenomedullary responses during stimulation of VLM and DM.  相似文献   
16.
The case of a patient in whom acute pericarditis was the initial manifestation of an idiopathic hypereosinophilia is reported. Endomyocardial abnormalities were not found by echocardiography. Response to prednisone therapy was good; symptoms, pericardial effusion and eosinophilia early disappeared after therapy. Some clinical aspects of this uncommon disease are discussed.  相似文献   
17.
Ten cases of pediatric fulminant hemophagocytic syndrome, encountered between 1986 and 1989, are described. They occurred in the summer, and the patients presented with fever, jaundice, hepatosplenomegaly, pancytopenia, coagulopathy, and abnormal liver function. Bone marrow studies revealed infiltration by atypical T-lymphoid cells, rare B immunoblasts, and mature histiocytes with hemophagocytosis. Initially, histiocytic medullary reticulosis was suspected in six cases. The clinical course was characterized by rapid deterioration, with a mean period of 16 days from onset of fever to death. The main causes of death were coagulopathy with multiple organ failure and opportunistic infection. In seven of eight cases studied by serologic assay and Southern blot hybridization, acute or active Epstein-Barr virus (EBV) infection was documented. It is suggested that an atypical or fulminant form of primary EBV infection distinct from classic infectious mononucleosis was prevalent in previously healthy children in Taiwan. Younger age involvement and seasonal clustering were characteristic of the disorder described.  相似文献   
18.
Summary In this study the technique of labelling the cell membrane with DPH fluorescence polarization was used to observe the membrane fluidity of B lymphocytic cell lines and tonsillar cells from healthy persons; the modulation effect on membrane-fluidity induced by McAbs against isotypic and idiotypic determinants of IgM from patients with leukemia was studied as well. The expression of the corresponding isotypic and idiotypic determinants of IgM on the cell membrane was determined. The results show that the membrane fluidity of leukemic cell lines is remarkably higher than that of tonsillar cells from healthy persons, and McAbs against isotypic determinants of leukemic IgM can enhance the membrane fluidity of all kinds of cells mentioned above. However, the anti-idiotypic monoclonal antibody increased only the membrane fluidity of leukemic cell lines. These results indicated that there was a close relationship between the effect of McAbs on cell membrane fluidity and the expression of corresponding isotypic and idiotypic determinants of IgM on the cell membrane.  相似文献   
19.
参芪胶囊的鉴别与含量测定方法研究   总被引:1,自引:0,他引:1  
对参区胶囊中黄芪、人参、当归、知母、黄连等味药进行了薄层鉴别。并对黄连中小檗碱进行了薄层光密度法测定,方法灵敏,重现性好,回收率100%,相对标准偏差RSD%=2.0(n=6)。  相似文献   
20.
The effects of electrical stimulation and microinjection of sodium glutamate (0.5 M) in the sympathetic pressor areas of the dorsal medulla (DM), ventrolateral medulla (VLM), and parvocellular nucleus (PVC) on the knee jerk, crossed extension, and evoked potential of the L5 ventral root produced by intermittent electrical stimulation were studied in 98 adult cats anesthetized with chloralose and urethane. During electrical and glutamate stimulation of these pressor areas, in addition to the rise of systemic arterial blood pressure marked inhibition of the spinal reflex was produced, indicating presence of neuronal perikarya responsible for these actions. Mild to moderate augmentation of spinal reflexes was also observed during brain stimulation but only in a few cases. The magnitude of the somatic effects among the pressor areas of the VLM, DM, and PVC subsequent to glutamate activation was about the same. Induced spinal reflex inhibition, independent from the baroreceptor and vagal influence, remained essentially unaltered after acute midcollicular decerebration. The inhibition was also observed in cats decerebellated 8-10 days in advance. The inhibition was not affected after bilateral electrolytic- or kainic-acid-induced lesions in the paramedian reticular nucleus (PRN). On the contrary, PRN-induced spinal reflex inhibition was attenuated after bilateral lesions in the DM or VLM. Data suggest that there coexists neuronal subpopulations in the VLM, DM, and PVC that can affect both the sympathetic pressor systems and spinal reflexes.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号