全文获取类型
收费全文 | 1248307篇 |
免费 | 73054篇 |
国内免费 | 1428篇 |
专业分类
耳鼻咽喉 | 16155篇 |
儿科学 | 40945篇 |
妇产科学 | 31657篇 |
基础医学 | 170081篇 |
口腔科学 | 31064篇 |
临床医学 | 107102篇 |
内科学 | 234244篇 |
皮肤病学 | 25268篇 |
神经病学 | 97462篇 |
特种医学 | 51724篇 |
外国民族医学 | 202篇 |
外科学 | 191378篇 |
综合类 | 24233篇 |
现状与发展 | 1篇 |
一般理论 | 266篇 |
预防医学 | 92076篇 |
眼科学 | 27582篇 |
药学 | 95665篇 |
7篇 | |
中国医学 | 3489篇 |
肿瘤学 | 82188篇 |
出版年
2019年 | 7967篇 |
2018年 | 32256篇 |
2017年 | 25430篇 |
2016年 | 28767篇 |
2015年 | 12382篇 |
2014年 | 16337篇 |
2013年 | 23270篇 |
2012年 | 37668篇 |
2011年 | 52718篇 |
2010年 | 36986篇 |
2009年 | 28980篇 |
2008年 | 48798篇 |
2007年 | 53037篇 |
2006年 | 33581篇 |
2005年 | 33442篇 |
2004年 | 33261篇 |
2003年 | 32965篇 |
2002年 | 30130篇 |
2001年 | 60402篇 |
2000年 | 61988篇 |
1999年 | 51181篇 |
1998年 | 12676篇 |
1997年 | 11218篇 |
1996年 | 11121篇 |
1995年 | 10438篇 |
1994年 | 9460篇 |
1993年 | 8935篇 |
1992年 | 37854篇 |
1991年 | 36414篇 |
1990年 | 35917篇 |
1989年 | 34397篇 |
1988年 | 30990篇 |
1987年 | 30075篇 |
1986年 | 28288篇 |
1985年 | 26533篇 |
1984年 | 19261篇 |
1983年 | 16172篇 |
1982年 | 8878篇 |
1979年 | 17065篇 |
1978年 | 11440篇 |
1977年 | 10258篇 |
1976年 | 8869篇 |
1975年 | 10100篇 |
1974年 | 11706篇 |
1973年 | 11301篇 |
1972年 | 10780篇 |
1971年 | 10131篇 |
1970年 | 9300篇 |
1969年 | 8978篇 |
1968年 | 7949篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
21.
J Phua E S C Koay D Zhang L K Tai X L Boo K C Lim T K Lim 《The European respiratory journal》2006,28(4):695-702
Levels of the soluble form of the triggering receptor expressed on myeloid cells (sTREM)-1 are elevated in severe sepsis. However, it is not known whether sTREM-1 measurements can distinguish milder bacterial infections from noninfectious inflammation. The present authors studied whether serum sTREM-1 levels differ in community-acquired pneumonia, exacerbations of chronic obstructive pulmonary disease (COPD), asthma and controls, and whether sTREM-1 may be used as a surrogate marker for the need for antibiotics. Serum sTREM-1 levels in 150 patients with pneumonia, COPD and asthma exacerbations and 62 healthy controls were measured. Serum sTREM-1 levels were significantly elevated in pneumonia (median 295.2 ng x mL(-1)), COPD (280.3 ng x mL(-1)) and asthma exacerbations (184.0 ng x mL(-1)) compared with controls (83.1 ng x mL(-1)). Levels were higher in pneumonia and Anthonisen type 1 COPD exacerbations than in type 2 and 3 COPD and asthma exacerbations. The area under the receiver operating characteristics curve for sTREM-1 as a surrogate marker for the need for antibiotics was 0.77. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 were elevated predominantly in pneumonia and Anthonisen type 1 COPD exacerbations versus type 2 and 3 chronic obstructive pulmonary disease exacerbations, asthma and controls. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 has moderate but insufficient accuracy as a surrogate marker for the need for antibiotics in lower respiratory tract infections. 相似文献
22.
23.
24.
25.
26.
27.
28.
C F A Peralta P Cavoretto B Csapo O Falcon K H Nicolaides 《Ultrasound in obstetrics & gynecology》2006,27(2):128-133
OBJECTIVE: To establish reference intervals for the fetal right, left and total lung volumes and heart volume between 12 and 32 weeks of gestation. METHODS: Fetal lung and heart volumes were measured using three-dimensional (3D) ultrasound in 650 normal singleton pregnancies at 12-32 weeks. The VOCAL (Virtual Organ Computer-aided AnaLysis) technique was used to obtain a sequence of six sections of each lung and the heart around a fixed axis, each after a 30 degrees rotation from the previous one. The rotation axis for the lungs extended from the apex to the upper limit of the diaphragm dome, and the rotation axis for the heart extended from its apex to its connection to the great vessels. The contour of each of these organs was drawn manually in the six different rotation planes to obtain the 3D volume measurement. In 60 cases the fetal lungs and heart volumes were measured by the same sonographer twice and also by a second sonographer once in order to compare the measurements and calculate intra- and interobserver agreement. RESULTS: The total lung volume and heart volume increased with gestation, from respective mean values of 1.6 and 0.6 mL at 12 weeks to 10.9 and 4.3 mL at 20 weeks and 49.3 and 26.6 mL at 32 weeks. The right to left lung volume ratio did not change significantly with gestation (median, 0.7), whereas the heart to total lung volume ratio increased with gestation from about 0.3 at 12 weeks to 0.5 at 32 weeks. In the Bland-Altman plot, the difference between paired measurements by two sonographers was, in 95% of the cases, less than 0.05, 0.5 and 1.9 mL for each lung at 12-13, 19-22 and 29-32 weeks, respectively, and the corresponding values for the heart volumes were 0.04, 0.4 and 2.3 mL. CONCLUSIONS: In normal fetuses the lung and heart volumes increase between 12 and 32 weeks of gestation. The extent to which in pathological pregnancies possible deviations in these measurements from normal prove to be useful in the prediction of outcome remains to be determined. 相似文献
29.
K M Sarraf M Abdalla O Al-Omari M G Sarraf 《Ultrasound in obstetrics & gynecology》2006,27(2):220-221
We report the case of a 38-year-old woman who presented with chronic lower abdominal pain. Her past medical history included a splenectomy due to abdominal trauma. Ultrasound examination revealed four pelvic tumors which, upon laparotomy, were found to be the result of splenosis. Approximately 100 cases of splenosis have been reported but only a minority of them have been published in the gynecological literature. Our case indicates that those involved in pelvic scanning (even of asymptomatic women) and/or treating those complaining of lower abdominal pain or presenting with pelvic tumors should be aware of splenosis as a possible diagnosis. 相似文献
30.
H J Kim C H Kang Y T Kim S-W Sung J H Kim S M Lee C-G Yoo C-T Lee Y W Kim S K Han Y-S Shim J-J Yim 《The European respiratory journal》2006,28(3):576-580
Although surgical lung resection could improve prognosis in some patients with multidrug-resistant tuberculosis (MDR-TB), there are no reports on the optimal candidates for this surgery. The aim of the present study was to elucidate the prognostic factors for surgery in patients with MDR-TB. Patients who underwent lung resection for the treatment of MDR-TB between March 1993 and December 2004 were included in the present study. Treatment failure was defined as greater than or equal to two of the five cultures recorded in the final 12 months of treatment being positive, any one of the final three cultures being positive, or the patient having died during treatment. The variables that affected treatment outcomes were identified through univariate and multivariate logistic regression analysis. In total, 79 patients with MDR-TB were included in the present study. The treatment outcomes of 22 (27.8%) patients were classified as failure. A body mass index <18.5 kg x m(-2), primary resistance, resistance to ofloxacin and the presence of a cavitary lesion beyond the range of the surgical resection were associated with treatment failure. Low body mass index, primary resistance, resistance to ofloxacin and cavitary lesions beyond the range of resection are possible poor prognostic factors for surgical lung resection in multidrug-resistant tuberculosis patients. 相似文献