全文获取类型
收费全文 | 42351篇 |
免费 | 2024篇 |
国内免费 | 210篇 |
专业分类
耳鼻咽喉 | 349篇 |
儿科学 | 734篇 |
妇产科学 | 679篇 |
基础医学 | 5359篇 |
口腔科学 | 1042篇 |
临床医学 | 2825篇 |
内科学 | 10441篇 |
皮肤病学 | 681篇 |
神经病学 | 3001篇 |
特种医学 | 1577篇 |
外科学 | 7906篇 |
综合类 | 186篇 |
预防医学 | 1346篇 |
眼科学 | 477篇 |
药学 | 3041篇 |
中国医学 | 136篇 |
肿瘤学 | 4805篇 |
出版年
2023年 | 230篇 |
2022年 | 427篇 |
2021年 | 814篇 |
2020年 | 470篇 |
2019年 | 625篇 |
2018年 | 780篇 |
2017年 | 609篇 |
2016年 | 689篇 |
2015年 | 795篇 |
2014年 | 1012篇 |
2013年 | 1187篇 |
2012年 | 1898篇 |
2011年 | 1994篇 |
2010年 | 1143篇 |
2009年 | 937篇 |
2008年 | 1774篇 |
2007年 | 1898篇 |
2006年 | 1877篇 |
2005年 | 1936篇 |
2004年 | 1933篇 |
2003年 | 1821篇 |
2002年 | 1848篇 |
2001年 | 1697篇 |
2000年 | 1633篇 |
1999年 | 1563篇 |
1998年 | 562篇 |
1997年 | 471篇 |
1996年 | 417篇 |
1995年 | 371篇 |
1994年 | 353篇 |
1993年 | 304篇 |
1992年 | 1002篇 |
1991年 | 942篇 |
1990年 | 817篇 |
1989年 | 906篇 |
1988年 | 777篇 |
1987年 | 703篇 |
1986年 | 751篇 |
1985年 | 679篇 |
1984年 | 434篇 |
1983年 | 375篇 |
1982年 | 194篇 |
1981年 | 189篇 |
1979年 | 311篇 |
1978年 | 240篇 |
1977年 | 208篇 |
1975年 | 209篇 |
1974年 | 186篇 |
1973年 | 174篇 |
1971年 | 176篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
Tatsuhiko Kuroda Shiro Tanaka Mitsuru Saito Yumiko Shiraki Masataka Shiraki 《Calcified tissue international》2013,93(3):269-275
The aim of this cross-sectional cohort study was to clarify risk factors for severe vertebral fractures in postmenopausal Japanese women. Subjects were ambulatory volunteers age over 50 years who were recruited from a population of outpatients at a primary care institute. At registration, age, body mass index (BMI), bone mineral density (BMD), and present illness were investigated. Biochemical parameters including urinary levels of type I collagen cross-linked N-telopeptides (NTXs), and pentosidine and plasma levels of homocysteine were measured. Values were compared with different fracture grades (grade 0–3). A total of 1,475 postmenopausal women (66.6 ± 9.0 years) were included in the present study. Distributions of vertebral fracture grades were grade 1, 137 cases (9.3 %); grade 2, 124 cases (8.4 %); and grade 3, 162 cases (11.0 %). Age, BMI, BMD, NTX, pentosidine, and homocysteine were significantly associated with vertebral fracture in unadjusted analysis. In addition, a higher prevalence of hypertension was observed in patients with severe fracture. When comparing vertebral fracture grade 0 versus grade 2–3 by multiple regression analysis, pentosidine and homocysteine levels were a significant risk for moderate/severe vertebral fracture (odds ratio [OR] = 1.17, 95 % confidence interval [CI] 1.00–1.38, p = 0.049; OR = 1.22, 95 % CI 1.03–1.46, p = 0.013). Homocysteine levels were also a significant risk when comparing vertebral fracture grade 0 versus grade 3 (OR = 1.27, 95 % CI 1.04–1.58, p = 0.021). Plasma level of homocysteine was an independent risk for severe vertebral fractures. 相似文献
993.
994.
Endoscopic submucosal dissection (ESD) was introduced worldwide as a new treatment option for early gastric cancer. Our objective was to discuss the limited ESD reports available and to determine the lesions suitable for use in training endoscopists on which lesions are appropriate for ESD. We reviewed a series of ESD reports that have been written on various risk factors related to the resectability or curability of a variety of lesions. These published studies show that certain risk factors such as tumor size and location and the presence of ulceration are closely related to both resectability and curability. Because the combination of these risk factors resulted in a much higher risk than did any single factor, we recently established a 'risk assessment chart' to determine an individual's total risk of treatment failure for early gastric cancer that has been treated using ESD. This risk chart provides a clear indication that small, non-ulcerated lesions located in the lower third of the stomach have a high rate of curative resection and are technically less challenging if ESD is used. We suggest that trainees should gain ESD experience with such lesions before they start to perform ESD on more difficult lesion types that have a lower probability of curative resection. In addition, we suggest that this risk assessment chart is suitable for the pretreatment assessment of curability and the likelihood of successful en bloc resection. 相似文献
995.
Ota H Furuhashi M Ishimura S Koyama M Okazaki Y Mita T Fuseya T Yamashita T Tanaka M Yoshida H Shimamoto K Miura T 《American journal of hypertension》2012,25(10):1124-1130
BackgroundFatty acid-binding protein 4 (FABP4/A-FABP/aP2), a lipid chaperone, is expressed in both adipocytes and macrophages. Recent studies have shown secretion of FABP4 from adipocytes and association of elevated serum FABP4 level with obesity, insulin resistance, and atherosclerosis. However, little is known about the role of FABP4 in essential hypertension.MethodsWe first examined serum FABP4 concentrations in 18 normotensives (NT) and 30 nontreated essential hypertensives (EHT). The EHT were divided into 18 insulin-sensitive EHT (EHT-S) and 12 insulin-resistant EHT (EHT-R) based on their insulin-sensitivity index, the M value, determined by the hyperinsulinemic-euglycemic clamp technique. In the second study, we determined FABP4 levels in 30 young NT men with or without a family history of hypertension (FH(+) and FH(-), respectively; n = 15 each).ResultsSerum FABP4 level was significantly higher in the EHT-R than in the NT, whereas elevation of FABP4 level in the EHT-S was not statistically significant. FABP4 level was positively correlated with age, body mass index (BMI), blood pressure, and triglycerides and negatively correlated with the M value. FABP4 level was an independent predictor of mean arterial pressure after adjustment of age, gender, and adiposity. The FH(+) group had a significantly lower level of M value and higher level of FABP4 than did the FH(-) group, and FABP4 concentration was an independent determinant of the M value.ConclusionsFABP4 contributes to blood pressure elevation and atherogenic metabolic phenotype in hypertensives, and the elevation of FABP4 is predisposed by a family history of hypertension.American Journal of Hypertension 2012; doi:10.1038/ajh.2012.88. 相似文献
996.
997.
Hiroshi Tanaka Soichiro Hozawa Junya Kitada Masaru Fujii 《Allergology international》2012,61(3):385-392
Growing interest had been focused on the involvement of the small airways in asthma, and impulse oscillometry (IOS) has been utilized as pulmonary functions for detecting large and small airways diseases separately. IOS can measure respiratory resistance and reactance at multiple frequencies, not available by spirometry or body plethysmography, is non-invasive techniques and convenient for elderly patients with a low dependency on cooperation during tidal breathing. IOS indices were well correlated with not only predicted FEV1 but also FEF25-75, residual volume/total lung capacity, delta N2 of a single nitrogen washout test which representing air trapping and inhomogeneous ventilation in the distal lung. These parameters and QOL scores were improved by additional transdermal long-acting beta-2 agonist patch even in well-controlled elderly asthma treating with inhaled corticosteoids alone. IOS may have a complementary role of spirometry in detecting subtle airways changes in general practice. However, systemic studies are required to investigate the clinical implication of each IOS index. 相似文献
998.
999.
1000.
Hida S Chikamori T Tanaka H Igarashi Y Shiba C Usui Y Hatano T Yamashina A 《Circulation journal》2012,76(8):1942-1952