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   26552篇
  免费   1352篇
  国内免费   164篇
耳鼻咽喉   238篇
儿科学   603篇
妇产科学   294篇
基础医学   3643篇
口腔科学   583篇
临床医学   1554篇
内科学   6878篇
皮肤病学   600篇
神经病学   2032篇
特种医学   1148篇
外科学   4450篇
综合类   131篇
预防医学   721篇
眼科学   636篇
药学   1592篇
中国医学   42篇
肿瘤学   2923篇
  2023年   163篇
  2022年   322篇
  2021年   546篇
  2020年   300篇
  2019年   391篇
  2018年   554篇
  2017年   425篇
  2016年   521篇
  2015年   557篇
  2014年   794篇
  2013年   899篇
  2012年   1527篇
  2011年   1711篇
  2010年   950篇
  2009年   856篇
  2008年   1500篇
  2007年   1659篇
  2006年   1621篇
  2005年   1760篇
  2004年   1789篇
  2003年   1801篇
  2002年   1694篇
  2001年   433篇
  2000年   369篇
  1999年   432篇
  1998年   434篇
  1997年   346篇
  1996年   346篇
  1995年   289篇
  1994年   258篇
  1993年   234篇
  1992年   258篇
  1991年   213篇
  1990年   191篇
  1989年   184篇
  1988年   184篇
  1987年   146篇
  1986年   171篇
  1985年   147篇
  1984年   140篇
  1983年   113篇
  1982年   85篇
  1981年   89篇
  1980年   85篇
  1979年   77篇
  1978年   65篇
  1977年   65篇
  1976年   55篇
  1975年   44篇
  1972年   33篇
排序方式: 共有10000条查询结果,搜索用时 937 毫秒
71.
72.
Primary extranodal malignant lymphoma frequently occurs in the gastrointestinal tract; however, it is rarely encountered in the rectum. We report herein the case of an 85-year-old man who underwent abdominoperineal resection for primary malignant lymphoma of the rectum, and 1 year later, developed hematemesis caused by gastric metastasis. To our knowledge this is the first case report of such distant metastasis developing from malignant lymphoma of the rectum.  相似文献   
73.
74.
Two elderly women complaining of intermittent claudication complicated with persistent sciatic artery are herein reported. A direct femoral arteriogram showed hypoplasty of the superficial femoral artery and an unnatural anatomical relationship between the distal superficial femoral artery and the proximal popliteal artery, thus suggesting the presence of persistent sciatic artery. The diagnosis of persistent sciatic artery was finally made based on the aortography findings including the iliac arterial system and computed tomography (CT) scan. Magnetic resonance imaging (MRI) was helpful to demonstrate the entire image of this anomaly in cases with non-thrombolized sciatic artery. These diagnostic methods were useful in designing the optimal surgical strategy. The first case with a gluteal pulsating mass underwent exclusion of the persistent sciatic artery including the aneurysm through a retroperitoneal approach with a combination of femorotibial bypass, while the second case with thrombosed persistent sciatic artery only underwent femoropopliteal bypass. To recognize such a rare lesion, awareness of the differential diagnosis is important, and to provide appropriate treatment, an accurate whole image including adequate angiography, a CT scan, and magnetic resonance imaging is necessary.  相似文献   
75.
76.
In order to find useful information for the establishment of new treatment method to alcohol dependence, we investigated the change of the body image of patients with alcohol dependence before and after the treatment. HABIT (Haga Body Image Test), a questionnaire about body image developed in department of psychiatry in Kyoto Prefectural University of Medicine, was used to examine the change of body image between pre- and post-3-month conventional treatment program in 46 patients with alcohol dependence hospitalized into special institutions for treatment of the disease in Kyoto. Patients with poor outcome of the treatment showed improvement of body image on visceral function, feeling of appetite and outward appearance, while patients with good outcome indicated no significant change in these aspects. This finding likely suggests that the treatment would result in good outcome in patients having stable feeling of physical health, and the cognitive treatment approach about these aspects of body image should be performed on the patients with poor treatment outcome. On the other hand, the body image about motor function showed significantly higher score in the patients approach for the patients with poor outcome to become aware of their physical activity would be effective.  相似文献   
77.
Disrupted-In-Schizophrenia-1 (DISC1) is a promising candidate gene for schizophrenia (SZ) and bipolar disorder (BP), but its basic biology remains to be elucidated. Accumulating genetic evidence supports that DISC1 is associated with some aspects of cognitive functions relevant to SZ and BP. Here, we provide a summary of the current updates in biological studies of DISC1. Disrupted-In-Schizophrenia-1, preferentially expressed in the forebrain, has multiple isoforms with potential posttranslational modifications. Disrupted-In-Schizophrenia-1 protein occurs in multiple subcellular compartments, which include the centrosome, microtubule fractions, postsynaptic densities, actin cytoskeletal fractions, the mitochondria, and the nucleus. Recent studies have clarified that DISC1 mediates at least centrosome-dynein cascade and cyclic adenosine monophosphate (cAMP) signaling. Furthermore, both cytogenetic and cell biological studies consistently suggest that an overall loss of DISC1 function (either haploinsufficiency or dominant-negative, or both) may be associated with SZ and BP. On the basis of these findings, production of DISC1 genetically engineered mice is proposed as a promising animal model for SZ and BP. Several groups are currently generating DISC1 mice and starting to characterize them. In this review, the advantages and disadvantages of each animal model are discussed.  相似文献   
78.
We report a simple, sensitive, and rapid quantitation of Amitraz in plasma after Extrelut-3 column extraction by gas chromatography with nitrogen-phosphorus detection (GC-NPD). The plasma sample was diluted four-fold with borate buffer (0.01M, pH 11), put into an Extrelut-3 column, left for 15 min, and then eluted with 15 mL of n-hexane. The n-hexane eluate was evaporated under nitrogen gas flow at room temperature. The residue was reconstituted with 0.1 mL of acetone containing nitrazepam as an internal standard. A 2-microL aliquot was injected into a wide-bore capillary column GC-NPD. The detection limit was 0.5 ng/mL and linearity was obtained in the range of 1-200 ng/mL. Amitraz in the buffer at pH 11 remained stable in a freezer for one week at -20 degrees C. The GC-NPD method was found useful in studying the pharmacokinetics of a single dose intravenous administration of Amitraz to a dog.  相似文献   
79.
Genetic alteration in carcinoid tumors of the lung.   总被引:1,自引:0,他引:1  
Surgically resected specimens of 13 carcinoid tumors of the lung including nine typical carcinoids and four atypical carcinoids, and eight salivary gland type carcinomas (six mucoepidermoid carcinomas and two adenoid cystic carcinomas) were analyzed regarding p53 expression, loss of heterozygosity (LOH) in chromosome 3p, 9p, and K-ras mutation. The overexpression of p53 was identified in four atypical carcinoid tumors, one mucoepidermoid carcinoma, and one adenoid cystic carcinoma, however, none of typical carcinoids showed p53 immunoreactivity. LOH in 3p14 was demonstrated in three of seven informative cases in all tumors. LOH in 9p was demonstrated in two of five informative cases in all tumors. Two of three cases with LOH at 3p14 had a poor prognosis, one of which also had LOH at 9p. No mutation of the K-ras gene was observed in any of these tumors. These data thus indicate that p53 overexpression might distinguish atypical carcinoid tumors from typical tumors and might therefore be useful as an adjunct modality in the differential diagnosis of pulmonary carcinoid tumors. The presence of LOH at 3p14 or 9p may thus help to identify lung cancer patients with a poor prognosis.  相似文献   
80.
We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG) from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients (36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits, delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological dysfunction compared to hypothermic CPB.  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