全文获取类型
收费全文 | 1028篇 |
免费 | 63篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 39篇 |
妇产科学 | 21篇 |
基础医学 | 121篇 |
口腔科学 | 24篇 |
临床医学 | 85篇 |
内科学 | 180篇 |
皮肤病学 | 53篇 |
神经病学 | 53篇 |
特种医学 | 159篇 |
外科学 | 135篇 |
综合类 | 23篇 |
预防医学 | 54篇 |
眼科学 | 12篇 |
药学 | 87篇 |
中国医学 | 1篇 |
肿瘤学 | 56篇 |
出版年
2023年 | 5篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 21篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 24篇 |
2014年 | 30篇 |
2013年 | 31篇 |
2012年 | 31篇 |
2011年 | 34篇 |
2010年 | 39篇 |
2009年 | 51篇 |
2008年 | 36篇 |
2007年 | 39篇 |
2006年 | 50篇 |
2005年 | 50篇 |
2004年 | 45篇 |
2003年 | 33篇 |
2002年 | 38篇 |
2001年 | 33篇 |
2000年 | 26篇 |
1999年 | 15篇 |
1998年 | 25篇 |
1997年 | 39篇 |
1996年 | 22篇 |
1995年 | 24篇 |
1994年 | 19篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 19篇 |
1989年 | 22篇 |
1988年 | 15篇 |
1987年 | 16篇 |
1986年 | 20篇 |
1985年 | 21篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1981年 | 15篇 |
1980年 | 16篇 |
1979年 | 6篇 |
1978年 | 11篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1971年 | 7篇 |
1969年 | 6篇 |
排序方式: 共有1104条查询结果,搜索用时 15 毫秒
21.
22.
Objective
The aim of this study was the analysis of long-term results in patients with hemodynamically significant mitral valve disease due to extensively calcified mitral annulus who underwent decalcification and patch reconstruction.Patients and Methods
Between 1996 and 2008 a total of 109?patients underwent surgery for extensive calcification and severe mitral insufficiency and mitral stenosis. The mean age of the patients (65?women and 44?men) was 66.4±13.8?years. In 53?patients (49%) mitral valve repair was performed and the remaining 56?patients (51%) received a mitral valve replacement. Of the patients 64 (59%) required concomitant surgery. The mean follow up time was 96±48?months.Results
The in-hospital and late mortality was 8.3% (9?patients) and 25.6% (28?patients), respectively. The actuarial survival rates at 5, 8 and 12?years were 88.1%, 76.2% and 66.1%, respectively. Echocardiographic follow-up presented a mitral insufficiency grade III in 4?patients (6%). None of the patients had a mitral insufficiency grade IV. A significant reduction of left atrium diameter, of the LVEDD as well as the mean transvalvular gradient was observed. Freedom from reoperation at 5 and 8?years was 96.4% and 91.8%, respectively. Systemic hypertension, diabetes mellitus, age older than 65?years, concomitant aortic valve replacement, concomitant procedures, chronic renal insufficiency and cardiac decompensation in the medical history were found to be predictors for significantly increased early or late mortality.Conclusion
The long-term results strongly suggest that en bloc decalcification and patch reconstruction of the mitral annulus can be safely undertaken in high risk patients. 相似文献23.
Oral Diseases (2012) 19 , 46–58 Sjögren’s syndrome (SjS) is one of the most common autoimmune rheumatic diseases, clinically characterized by xerostomia and keratoconjunctivitis sicca. We investigated the following controversial topics: (i) Do we have reliable ways of assessing saliva production? (ii) How important are the quantity and quality of saliva? (iii) Are only anti‐SSA/Ro and anti‐SSB/La relevant for the diagnosis of SjS? (iv) Are the American‐European Consensus criteria (AECC) the best way to diagnose SjS? Results from literature searches suggested the following: (i) Despite the fact that numerous tests are available to assess salivation rates, direct comparisons among them are scarce with little evidence to suggest one best test. (ii) Recent developments highlight the importance of investigating the composition of saliva. However, more research is needed to standardize the methods of analysis and collection and refine the quality of the accumulating data. (iii) In addition to anti‐Ro/La autoantibodies, anti α‐fodrin IgA and anti‐MR3 autoantibodies seem to be promising diagnostic markers of SjS, but more studies are warranted to test their sensitivity and specificity. (iv) AECC are classification, not diagnostic criteria. Moreover, recent innovations have not been incorporated into these criteria. Consequently, treatment directed to patients diagnosed using the AECC might exclude a significant proportion of patients with SjS. 相似文献
24.
25.
Emina Mocevic Ina O Specht Jacob L Marott Aleksander Giwercman Bo AG J?nsson Gunnar Toft Thomas Lundh Jens Peter Bonde 《Asian journal of andrology》2013,15(1):97-104
Several animal studies indicate that mercury is a male reproductive toxicant, but human studies are few and contradictory. We examined semen characteristics and serum levels of reproductive hormones in relation to environmental exposure to mercury. Blood and semen samples were collected from 529 male partners of pregnant women living in Greenland, Poland and Ukraine between May 2002 and February 2004. The median concentration of the total content of mercury in whole blood was 9.2 ng ml−1 in Greenland (0.2–385.8 ng ml−1), 1.0 ng ml−1 in Poland (0.2–6.4 ng ml−1) and 1.0 ng ml−1 in Ukraine (0.2–4.9 ng ml−1). We found a significantly positive association between the blood levels of mercury and serum concentration of inhibin B in men from Greenland (β=0.074, 95% confidence interval (CI)=0.021 to 0.126) and in an analysis including men from all three regions (β=0.067, 95% CI=0.024 to 0.110). The association may be due to beneficial effects of polyunsaturated fatty acids (PUFAs), which are contained in seafood and fish. No significant association (P>0.05) was found between blood concentrations of mercury and any of the other measured semen characteristics (semen volume, total sperm count, sperm concentration, morphology and motility) and reproductive hormones (free androgen index (FAI), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone and LH×testosterone) in any region. In conclusion, the findings do not provide evidence that environmental mercury exposure in Greenlandic and European men with median whole blood concentration up to 10 ng ml−1 has adverse effects on biomarkers of male reproductive health. 相似文献
26.
27.
Letter: concordance of SVR4 and SVR12 following direct‐acting anti‐viral treatment in Egypt 下载免费PDF全文
28.
29.
30.
Veglio F Rabbia F Melchio R Schiavone D De Micheli AG Chiandussi L 《Blood pressure monitoring》1996,1(2):115-120
OBJECTIVE: To evaluate and compare the effects of lisinopril versus atenolol administration on the diurnal blood pressure profile and the nocturnal blood pressure fall in young mild-to-moderate essential hypertensives.METHODS: Thirty patients were studied. After a 2-week placebo run-in period, they were single-blind randomly assigned to receive 20 mg lisinopril or 100 mg atenolol. Using a SpaceLabs 90207 device, their ambulatory blood pressure was measured before and after 12 weeks of therapy. The readings were analysed using Fourer series with four harmonics. RESULTS: Lisinopril and atenolol administration significantly decreased office and ambulatory blood pressure values compared with the placebo period. The daily blood pressure curves obtained from Fourier analysis showed that the circadian rhythm was not altered by lisinopril and atenolol administration. From the night:day ratio for the nocturnal blood pressure fall, we found that atenolol administration minimized the average night-time blood pressure dip by increasing the number of non-dippers. In contrast, lisinopril administration did not modify the day-night difference, preserving the nocturnal blood pressure fall. CONCLUSION: Lisinopril and atenolol administration as a first-step treatment of young essential hypertensives produced comparable degrees of diurnal control of arterial pressure. The blood pressure fall at night in patients treated with atenolol was slightly less than that found with lisinopril treatment. 相似文献