全文获取类型
收费全文 | 1276825篇 |
免费 | 92488篇 |
国内免费 | 1987篇 |
专业分类
耳鼻咽喉 | 18185篇 |
儿科学 | 42257篇 |
妇产科学 | 37813篇 |
基础医学 | 186997篇 |
口腔科学 | 35382篇 |
临床医学 | 108114篇 |
内科学 | 251440篇 |
皮肤病学 | 26499篇 |
神经病学 | 99170篇 |
特种医学 | 49986篇 |
外国民族医学 | 369篇 |
外科学 | 197589篇 |
综合类 | 26514篇 |
现状与发展 | 1篇 |
一般理论 | 300篇 |
预防医学 | 92593篇 |
眼科学 | 29058篇 |
药学 | 97755篇 |
1篇 | |
中国医学 | 2496篇 |
肿瘤学 | 68781篇 |
出版年
2018年 | 11808篇 |
2015年 | 11610篇 |
2014年 | 15995篇 |
2013年 | 24344篇 |
2012年 | 33543篇 |
2011年 | 35937篇 |
2010年 | 21209篇 |
2009年 | 20013篇 |
2008年 | 34976篇 |
2007年 | 37941篇 |
2006年 | 38498篇 |
2005年 | 37793篇 |
2004年 | 36379篇 |
2003年 | 35366篇 |
2002年 | 34919篇 |
2001年 | 58094篇 |
2000年 | 59586篇 |
1999年 | 50688篇 |
1998年 | 14235篇 |
1997年 | 12809篇 |
1996年 | 13072篇 |
1995年 | 12346篇 |
1994年 | 11758篇 |
1993年 | 10860篇 |
1992年 | 40986篇 |
1991年 | 40360篇 |
1990年 | 39889篇 |
1989年 | 38709篇 |
1988年 | 36112篇 |
1987年 | 35349篇 |
1986年 | 33727篇 |
1985年 | 32136篇 |
1984年 | 23923篇 |
1983年 | 20818篇 |
1982年 | 12378篇 |
1981年 | 10928篇 |
1980年 | 10204篇 |
1979年 | 22637篇 |
1978年 | 15879篇 |
1977年 | 13731篇 |
1976年 | 12970篇 |
1975年 | 14202篇 |
1974年 | 16683篇 |
1973年 | 16077篇 |
1972年 | 15318篇 |
1971年 | 14229篇 |
1970年 | 13214篇 |
1969年 | 12732篇 |
1968年 | 11978篇 |
1967年 | 10479篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
J. I. Bilbao M.D J. Rodriguez-Cabello J. Longo G. Zornoza J. Páramo F. J. Lecumberri 《Abdominal imaging》1989,14(1):326-328
We present a case report of a patient suffering from portal and superior mesenteric vein thrombosis secondary to splenectomy. No surgical procedure could be performed due to the extension of thrombus.Local fibrinolysis treatment with urokinase through a percutaneous transhepatic approach was decided upon, and this procedure had a successful patient outcome. 相似文献
902.
903.
A 64-year-old woman presented in shock. The computed tomography (CT) scan confirmed rupture of the left diaphragm with strangulation. Three days after surgery, the patient developed herniation of abdominal contents on the right side with cardiorespiratory collapse. Marlex mesh was used to repair on the right side. Postoperatively, she needed partial gastrectomy for massive duodenal ulcer bleeding. A dual chamber pacemaker was used to correct the complete heart block. 相似文献
904.
Insulin-like growth factors (IGF-I and -II) are peptide growth factors that may be important for neonatal development. Specific high affinity IGF binding proteins (BPs) have been characterized in serum and extracellular fluids. The major serum binding complex in the adult has an apparent Mr of 150 K, while the predominant BP in the neonate is approximately 30 K. In the rat, the transition from the neonatal BP to the adult form occurs during the third postnatal week, concomitant with an increase in serum IGF-I and a decrease in serum IGF-II concentrations. Using specific RIAs and Western ligand blot analyses we have characterized the changes in serum IGF and IGF BPs, respectively, during the early postnatal period. Seven BPs were identified in serum with apparent Mr values of 42, 41, 40, 38, 28, 26, and 22 K. After deglycosylation, the 42, 41, 40, and 38 K BPs were reduced to two bands with apparent Mr values of 35 and 32 K, while the 28, 26, and 22 K BP were unchanged. In the neonate, the 28, 26, and 22 K BPs were present, with the 28 K BP in highest concentration. With increasing age, the 28 K BP decreased and the 42, 41, 40, and 38 K BPs appeared at approximately 19 days of age. Comparison of Western ligand blots of neonatal serum, BRL-3A conditioned media, rat amniotic fluid, and rat cerebrospinal fluid (CSF) demonstrated that all contained a prominent 28 K BP. A polyclonal antibody (alpha Hec 1) developed against the 31 K human IGF-BP (hBP-31) immunoprecipitated the 28 K BP from neonatal rat serum, BRL-3A media, rat amniotic fluid, and rat CSF, but did not react with adult rat serum. These findings suggest that, in the rat, the predominant neonatal serum BP is structurally and immunologically similar to the major BRL-3A, amniotic fluid, and CSF BPs, but distinct from the predominant adult serum BP. 相似文献
905.
Elevated serum levels of keratan sulfate (KS) and hyaluronate (HA) in patients with osteoarthritis (OA) have been reported. We measured KS and HA in dogs to determine if there was an elevation of these serum glycosaminoglycans in a canine model of OA. A single intraarticular injection of 1 mg of chymopapain into a shoulder joint increased serum KS by tenfold, and HA by less than twofold, in 24 hours. Serum KS and HA levels were 3-5-fold higher in dogs younger than 2 months of age than in older dogs. Serum KS and HA concentrations and synovial fluid KS concentrations were unrelated to spontaneous cartilage degeneration in 1-year-old dogs. Higher KS levels in synovial fluid correlated with higher KS levels in serum (r = 0.54, P less than 0.025). The mean KS concentration in sera of older dogs (greater than 3 years old) with OA was 37% higher than that in disease-free controls, but the difference between the groups was not statistically significant. Thus, elevated levels of serum KS and HA do not appear to have clinical significance in this model of OA. 相似文献
906.
Natural history of aortoarteritis (Takayasu's disease) 总被引:8,自引:0,他引:8
The natural history of aortoarteritis was studied in 88 patients (54 women and 34 men). The average age was 24.0 +/- 8.8 years at onset of symptoms and 28.3 +/- 9.9 years at diagnosis. The follow-up period was 83.6 +/- 74.4 months from onset and 33.2 +/- 37.0 months from diagnosis. Ten patients (11.4%) died during follow-up (0.016 deaths/patient year), and 22 patients (25%) suffered major nonfatal events (0.042 events/patient year). The cumulative survival at 5 and 10 years after the onset was 91.0 +/- 3.3% and 84.0 +/- 5.6% (mean +/- SEM), respectively. The event-free survival rates at the same intervals after onset were 74.9 +/- 5.0% and 64.0 +/- 7.4%, respectively. The overall survival and event-free survival at 10 years after diagnosis was 80.3 +/- 6.5% and 61.6 +/- 7.5%, respectively. Patients with no complications or a mild single complication at diagnosis had a higher event-free survival rate than those with severe single complication or multiple complications at 5 years--97.0 +/- 2.9% and 59.7 +/- 7.3%, respectively (p less than 0.001). Severe hypertension (p less than 0.01), severe functional disability (p less than 0.01), and evidence of cardiac involvement (p less than 0.05) were good predictors of either death or major event on follow-up. These data are useful in making an objective assessment of the prognosis and in planning elective interventions. 相似文献
907.
Plasma D-dimer (DD) and thrombin--antithrombin III complex (TAT) were measured with ELISAs in 99 patients investigated by 102 ventilation--perfusion lung scintigraphy because of suspected pulmonary embolism. High-probability lung scan was associated with increased DD (more than 500 ng/ml) and TAT (more than 4.1 ng/ml) levels (sensitivity of 100 and 70%, respectively). The corresponding figures of specificity were 81 and 42%. In the 56 patients with low-probability or indeterminate probability scans, 31 (55%) had DD concentrations of less than 500 ng/ml. These preliminary data suggest that a plasma DD concentration of less than 500 ng/ml might rule out the diagnosis of pulmonary embolism in suspected patients with an inconclusive lung scanning. 相似文献
908.
T W Findley M G Stineman 《American journal of physical medicine & rehabilitation / Association of Academic Physiatrists》1989,68(5):240-251
The process of data entry and initial analysis to locate data errors is described. Basic terms are defined and a simple method of entering data by using word processing software is illustrated. Data checking is done by using visual check of the raw data. Statistical programs are then used to locate possible data errors by finding data points (outliers) that are very different from the average. Special graphic output of statistical programs, scatterplots and box and whisker plots can be used to further locate questionable data. Examples of data entry forms and annotated step by step data cleaning with the use of inexpensive programs for personal computers are presented. 相似文献
909.
A Goldfarb J Weinreb W G Daniel I Kronzon 《Journal of the American Society of Echocardiography》1989,2(5):350-353
A patient who had right and left atrial membranes was examined. The diagnosis and the hemodynamic significance of both membranes were detailed by transesophageal echocardiography and were confirmed by magnetic resonance imaging. Transesophageal imaging was found to be superior to routine echocardiography in visualization of these atrial structures. 相似文献
910.
Critically ill cardiac patients often undergo mechanical ventilation. The interplay between pulmonary and cardiac mechanics is complicated and in many cases may result in impaired transfer of O2 from the atmosphere to the tissues. This article addresses the principles of pulmonary and peripheral gas exchange, as well as the mechanical effects of respiration on the circulation. 相似文献