全文获取类型
收费全文 | 5147篇 |
免费 | 366篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 82篇 |
儿科学 | 203篇 |
妇产科学 | 121篇 |
基础医学 | 571篇 |
口腔科学 | 109篇 |
临床医学 | 334篇 |
内科学 | 1300篇 |
皮肤病学 | 75篇 |
神经病学 | 368篇 |
特种医学 | 528篇 |
外科学 | 673篇 |
综合类 | 54篇 |
一般理论 | 1篇 |
预防医学 | 322篇 |
眼科学 | 58篇 |
药学 | 348篇 |
1篇 | |
中国医学 | 9篇 |
肿瘤学 | 368篇 |
出版年
2023年 | 17篇 |
2022年 | 50篇 |
2021年 | 103篇 |
2020年 | 44篇 |
2019年 | 85篇 |
2018年 | 124篇 |
2017年 | 75篇 |
2016年 | 97篇 |
2015年 | 96篇 |
2014年 | 143篇 |
2013年 | 183篇 |
2012年 | 207篇 |
2011年 | 244篇 |
2010年 | 147篇 |
2009年 | 172篇 |
2008年 | 220篇 |
2007年 | 234篇 |
2006年 | 236篇 |
2005年 | 215篇 |
2004年 | 191篇 |
2003年 | 197篇 |
2002年 | 178篇 |
2001年 | 159篇 |
2000年 | 181篇 |
1999年 | 132篇 |
1998年 | 115篇 |
1997年 | 100篇 |
1996年 | 112篇 |
1995年 | 102篇 |
1994年 | 60篇 |
1993年 | 75篇 |
1992年 | 71篇 |
1991年 | 49篇 |
1990年 | 79篇 |
1989年 | 102篇 |
1988年 | 83篇 |
1987年 | 105篇 |
1986年 | 111篇 |
1985年 | 105篇 |
1984年 | 67篇 |
1983年 | 49篇 |
1982年 | 48篇 |
1981年 | 51篇 |
1980年 | 48篇 |
1979年 | 26篇 |
1978年 | 38篇 |
1977年 | 33篇 |
1976年 | 30篇 |
1975年 | 29篇 |
1970年 | 15篇 |
排序方式: 共有5525条查询结果,搜索用时 0 毫秒
1.
Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome. 相似文献
2.
3.
Willy Baccaglini Felipe A. Glina Cristiano Linck Pazeto Luis G. Medina Fernando Korkes Wanderley M. Bernardo Rene Sotelo Sidney Glina Giancarlo Marra Marco Moschini Xavier Cathelineau Rafael Sanchez-Salas 《Clinical genitourinary cancer》2021,19(1):3-11.e1
This meta-analysis focuses on the accuracy of upgrading to clinically significant prostate cancer (PCa) by multiparametric magnetic resonance imaging-targeted biopsy (MRI-TB) versus systematic biopsy (SB). We searched the Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, and Literatura Latino Americana em Ciências da Saúde databases through January 2020 for comparative, retrospective/prospective, paired-cohort, and randomized clinical trials with paired comparisons. The population consisted of patients with low-risk PCa in active surveillance with at least 1 index lesion on imaging. We evaluated the quality of evidence by using the Quality Assessment of Diagnostic Accuracy Studies-2 score. Group comparisons considered the differences between the area under the curve summary receiver operating characteristic curve in a 2-tailed method. We also compared the positive predictive value of the best single method (MRI-TB or SB) and the referral study test (combined biopsy, a combination of MRI-TB and SB). The meta-analysis included 6 studies enrolling 741 patients. The pooled sensitivity for the 2 groups was 0.79 (95% confidence interval, 0.74-0.83; I2 = 75%) and 0.67 (95% confidence interval, 0.63-0.74; I2 = 55.4%), respectively. The area under the curve for the MRI-TB and SB groups were 0.99 and 0.92 (P < .001), respectively. The positive predictive value for the MRI-TB and combined biopsy groups were similar. The accumulated evidence suggests better results for MRI-TB compared with SB. Therefore, use of MRI-TB alone may be preferable in patients in active surveillance harboring low-risk PCa. 相似文献
4.
5.
J.L. Bernat A.M. D'Alessandro F.K. Port T.P. Bleck S.O. Heard J. Medina S.H. Rosenbaum M.A. DeVita R.S. Gaston R.M. Merion M.L. Barr W.H. Marks H. Nathan K. O'Connor D.L. Rudow A.B. Leichtman P. Schwab N.L. Ascher R.A. Metzger V. Mc Bride W. Graham D. Wagner J. Warren F.L. Delmonico 《American journal of transplantation》2006,6(2):281-291
A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care. This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States. 相似文献
6.
7.
Adverse hemodynamic and clinical effects of encainide in severe chronic heart failure 总被引:1,自引:0,他引:1
STUDY OBJECTIVE: To evaluate the hemodynamic effects of the antiarrhythmic drug, encainide, in patients with severe chronic heart failure. DESIGN: Unblinded, before-after study. SETTING: Referral center for patients with heart failure. PATIENTS: Thirty patients with severe chronic heart failure and a left ventricular ejection fraction less than 40%. INTERVENTIONS: Invasive hemodynamic measurements were done (using a balloon-tipped thermodilution catheter) before and for 3 hours after a single oral dose of 50 mg of encainide. MEASUREMENTS AND MAIN RESULTS: Ninety to one hundred and twenty minutes after its administration, encainide produced a significant deterioration in cardiac performance, as reflected by a fall in cardiac index from 2.3 to 1.8 L/min.m2 body surface (mean change 0.5 +/- 0.1; P less than 0.001), a fall in stroke work index from 26 to 18 g.m/m2 (mean change 8 +/- 2; P less than 0.001), and an increase in left ventricular filling pressure from 19 to 22 mm Hg (mean change 3 +/- 2; P less than 0.05). These deleterious hemodynamic effects were accompanied by worsening symptoms of heart failure in 8 of the 30 patients. Serum levels of encainide and its metabolites, O-desmethylencainide and 3-methoxy-O-desmethylencainide, were within the therapeutic range in most patients. CONCLUSIONS: Encainide can cause adverse hemodynamic and clinical effects in patients with severe chronic heart failure. 相似文献
8.
Functional renal insufficiency during long-term therapy with captopril and enalapril in severe chronic heart failure 总被引:4,自引:0,他引:4
Renal function was evaluated in 104 patients with severe chronic heart failure whom we treated with captopril or enalapril. Seventy patients showed no change or an improvement in renal function (group A), and 34 patients developed functional renal insufficiency (group B). Before converting-enzyme inhibition, group B patients received higher doses of furosemide (p less than 0.02) and had lower central venous pressures (p less than 0.05) than group A patients. After 1 to 3 months of converting-enzyme inhibition, an excessive reduction in left ventricular filling pressure (to less than 15 mm Hg) or mean arterial pressure (to less than 60 mm Hg) was noted in 28 of 34 (82%) patients in group B but in only 22 of 70 patients in group A (31%) (p less than 0.001). At the end of the study, drug-induced azotemia resolved after a reduction in the dosage of diuretics, despite unaltered treatment with captopril and enalapril. Hence, the deterioration of renal function after converting-enzyme inhibition in heart failure is not a toxic or immunologic reaction to therapy but results from specific hemodynamic events that can be ameliorated by sodium repletion. 相似文献
9.
Both cyproterone acetate (CPA) and the gonadotrophin-releasing hormone
agonist (GnRHa) have been shown to be effective for the treatment of
hirsutism. We wished to compare the effectiveness of CPA in two standard
doses with GnRHa and add-back therapy and to compare the length of
remission after these treatments. A total of 60 hirsute hyperandrogenic
women was assigned to the following treatment groups: CPA 2 mg with 35
microg of ethinylestradiol for 21 days each month (Diane group), CPA 50 mg,
days 5-15, and ethinylestradiol 50 microg, days 5-25, each month (CPA
group) or Decapeptyl 3.75 mg i.m. every 28 days with the addition of
conjugated oestrogen 0.625 mg, days 1-21, and medroxyprogesterone acetate
10 mg, days 12-21 (GnRHa group). Hirsutism was graded by the
Ferriman-Gallwey-Lorenzo (FGL) index and anagen hair shaft diameters and
serum luteinizing hormone (LH) and testosterone were assessed before and
every 3 months during and after treatment. All women were treated for 1
year with 1 year follow-up. At baseline hirsutism and endocrine patterns
were similar in all groups. After one year of treatment, hirsutism
decreased in all groups but the changes were greater (P <0.05) in the
CPA and GnRHa groups than in the Diane group. Serum LH and testosterone
were lowest in the GnRHa group. After withdrawal, hirsutism increased
rapidly in the Diane and CPA groups and after 6 months, FGL scores and hair
shaft diameters were similar to pretreatment values. In the GnRHa group,
hirsutism increased more gradually and after 1 year of withdrawal, FGL
scores and hair diameters were significantly (P <0.05) less than
pretreatment values. Serum LH and testosterone increased rapidly in all
three groups reaching pretreatment values by 6 months. These data suggest
equal efficacy of the GnRHa and the high dose CPA regimen for the treatment
of hirsutism in hyperandrogenic women. GnRHa with add-back treatment
appears to result in a longer remission of hirsutism in comparison with
CPA.
相似文献
10.