全文获取类型
收费全文 | 1887篇 |
免费 | 104篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 152篇 |
妇产科学 | 58篇 |
基础医学 | 190篇 |
口腔科学 | 50篇 |
临床医学 | 175篇 |
内科学 | 449篇 |
皮肤病学 | 27篇 |
神经病学 | 41篇 |
特种医学 | 475篇 |
外科学 | 147篇 |
综合类 | 30篇 |
预防医学 | 55篇 |
眼科学 | 14篇 |
药学 | 56篇 |
中国医学 | 3篇 |
肿瘤学 | 90篇 |
出版年
2022年 | 5篇 |
2021年 | 11篇 |
2020年 | 10篇 |
2019年 | 12篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 25篇 |
2015年 | 32篇 |
2014年 | 30篇 |
2013年 | 61篇 |
2012年 | 34篇 |
2011年 | 26篇 |
2010年 | 82篇 |
2009年 | 66篇 |
2008年 | 40篇 |
2007年 | 34篇 |
2006年 | 37篇 |
2005年 | 22篇 |
2004年 | 29篇 |
2003年 | 34篇 |
2002年 | 35篇 |
2001年 | 21篇 |
2000年 | 42篇 |
1999年 | 37篇 |
1998年 | 140篇 |
1997年 | 119篇 |
1996年 | 127篇 |
1995年 | 94篇 |
1994年 | 77篇 |
1993年 | 82篇 |
1992年 | 24篇 |
1991年 | 29篇 |
1990年 | 20篇 |
1989年 | 66篇 |
1988年 | 49篇 |
1987年 | 50篇 |
1986年 | 48篇 |
1985年 | 50篇 |
1984年 | 26篇 |
1983年 | 38篇 |
1982年 | 35篇 |
1981年 | 21篇 |
1980年 | 36篇 |
1979年 | 15篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 23篇 |
1975年 | 24篇 |
1971年 | 5篇 |
1967年 | 5篇 |
排序方式: 共有2013条查询结果,搜索用时 296 毫秒
1.
A R Dias R N Melo O C E Gebara E A D'Amico A Nussbacher H W Halbe J A Pinotti 《Climacteric》2005,8(1):63-70
OBJECTIVES: To compare the effect of conjugated equine estrogens (CEE) and raloxifene on lipid profile and hemostasis. MATERIALS AND METHODS: A double-blind, randomized and parallel study was performed with 90 healthy postmenopausal women, aged 54 +/- 5 years, divided into three groups and submitted to daily therapy with either CEE 0.625 mg, raloxifene 60 mg or placebo for 4 months. The lipid profile, coagulation and fibrinolytic factors were analyzed. RESULTS: CEE increased the levels of high density lipoprotein cholesterol (HDL-C) from 49.0 to 56.8 mg/dl (p < 0.001), very low density lipoprotein cholesterol (VLDL-C) from 17.2 to 22.3 mg/dl (p < 0.001), and triglycerides from 86.0 to 111.7 mg/dl (p < 0.001), and decreased the levels of low density lipoprotein cholesterol (LDL-C) from 121.0 to 106.5 mg/dl (p < 0.001). The only significant effect of raloxifene was an increase in the levels of HDL-C from 46.0 to 47.8 mg/dl (p = 0.019). There was no significant reduction in LDL-C, from 115.5 to 110.2 mg/dl (p = 0.06), VLDL-C, from 21.7 to 20.0 mg/dl (p = 0.201), and triglycerides, from 108 to 100 mg/dl (p = 0.201). CEE decreased the levels of fibrinogen, from 370.5 to 326.8 g/l (p = 0.039) and the levels of antithrombin III, from 99.5 to 93.2% (p < 0.001). Raloxifene decreased the levels of fibrinogen, from 354.7 to 302.0 g/l (p = 0.009) and the levels of antithrombin III, from 102.4 to 98.5% (p = 0.039). CEE increased levels of protein C from 103.7 to 115.3 mg/l (p < 0.001) and raloxifene did not change the levels of protein C (107.9 to 105.1 mg/l; p = 0.158). CEE decreased the antigen levels of tissue plasminogen activator (t-PA) from 8.8 to 6.8 U/ml (p < 0.001), and of plasminogen activator inhibitor (PAI-1) from 30.8 to 21.6 U/ml (p < 0.010), whereas raloxifene had no significant effect on either t-PA, from 9.6 to 9.2 U/ml (p = 0.235) or PAI-1 antigen levels, from 32.1 to 30.4 U/ml (p = 0.538). CONCLUSION Both CEE and raloxifene exert significant effects on the lipid and coagulation profile. CEE had a more significant effect on fibrinolysis than raloxifene. These effects may have a significant impact on the cardiovascular risk that needs to be confirmed in larger studies. 相似文献
2.
JA HYEON KU CHEOL KWAK SEUNG-JUNE OH EUNSIK LEE SANG EUN LEE JAE-SEUNG PAICK 《International journal of urology》2004,11(7):489-493
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population. 相似文献
3.
4.
5.
L A D'Albuquerque J Gama-Rodrigues M F De Miranda T Genzini P Sakai A A Laudanna H W Pinotti 《International surgery》1991,76(3):137-141
Forty-six patients in the postoperative period of proximal gastric vagotomy (PGV) for duodenal ulcer (DU) were studied comparatively to verify whether the dividing of the gastroepiploic nerves (Rosati's maneuver) can reduce or not the occurrence of recurrent ulcer as it was proposed. Twenty-one patients who underwent PGV associated with Rosati's maneuver (PGV-R) were compared to 25 after standard PGV (PGV-S), according to several criteria: (1) clinical evaluation; (2) pre and postoperative basal and pentagastrin-stimulated gastric acidity; (3) postoperative basal and pentagastrin-stimulated serum pepsinogen; (4) postoperative basal and sham feeding-stimulated serum gastrin; (5) postoperative endoscopy; (6) endoscopic Congo red test. Both groups were similar (P greater than 0.05) as to age, sex, levels of preoperative gastric acidity and had a 24.4 month average follow-up (12 to 58 months). There has been no significant difference between the techniques studied as to clinical, secretory, morphological or hormonal gastric tests, although PGV-R proved more effective in reducing basal gastric acidity than PGV-S (P less than 0.05). We concluded that Rosati's maneuver does not improve the results obtained with PGV, although it provided greater reduction of basal gastric acidity than PGV-S. 相似文献
6.
7.
8.
9.
10.
Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging 总被引:2,自引:0,他引:2
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy. 相似文献