全文获取类型
收费全文 | 124290篇 |
免费 | 10564篇 |
国内免费 | 349篇 |
专业分类
耳鼻咽喉 | 1341篇 |
儿科学 | 3232篇 |
妇产科学 | 2165篇 |
基础医学 | 17479篇 |
口腔科学 | 1892篇 |
临床医学 | 13952篇 |
内科学 | 25187篇 |
皮肤病学 | 1418篇 |
神经病学 | 12081篇 |
特种医学 | 4790篇 |
外国民族医学 | 57篇 |
外科学 | 18557篇 |
综合类 | 1866篇 |
一般理论 | 133篇 |
预防医学 | 11028篇 |
眼科学 | 3075篇 |
药学 | 8703篇 |
中国医学 | 118篇 |
肿瘤学 | 8129篇 |
出版年
2023年 | 837篇 |
2022年 | 1288篇 |
2021年 | 3024篇 |
2020年 | 1744篇 |
2019年 | 2801篇 |
2018年 | 3203篇 |
2017年 | 2326篇 |
2016年 | 2463篇 |
2015年 | 2822篇 |
2014年 | 4116篇 |
2013年 | 5524篇 |
2012年 | 8442篇 |
2011年 | 8715篇 |
2010年 | 4859篇 |
2009年 | 4274篇 |
2008年 | 7283篇 |
2007年 | 7469篇 |
2006年 | 7098篇 |
2005年 | 6963篇 |
2004年 | 6507篇 |
2003年 | 5904篇 |
2002年 | 5483篇 |
2001年 | 2071篇 |
2000年 | 1998篇 |
1999年 | 1924篇 |
1998年 | 1357篇 |
1997年 | 1085篇 |
1996年 | 934篇 |
1995年 | 890篇 |
1994年 | 827篇 |
1993年 | 786篇 |
1992年 | 1315篇 |
1991年 | 1306篇 |
1990年 | 1196篇 |
1989年 | 1164篇 |
1988年 | 1160篇 |
1987年 | 1002篇 |
1986年 | 998篇 |
1985年 | 983篇 |
1984年 | 878篇 |
1983年 | 727篇 |
1982年 | 617篇 |
1981年 | 589篇 |
1980年 | 509篇 |
1979年 | 754篇 |
1978年 | 629篇 |
1977年 | 536篇 |
1976年 | 482篇 |
1974年 | 486篇 |
1973年 | 477篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
11.
Steven M Shechter Andrew J Schaefer R Scott Braithwaite Mark S Roberts 《Medical decision making》2006,26(5):550-553
The authors discuss techniques for Monte Carlo (MC) cohort simulations that reduce the number of simulation replications required to achieve a given degree of precision for various output measures. Known as variance reduction techniques, they are often used in industrial engineering and operations research models, but they are seldom used in medical models. However, most MC cohort simulations are well suited to the implementation of these techniques. The authors discuss the cost of implementation versus the benefit of reduced replications. 相似文献
12.
OBJECTIVE: To study the effect of high-frequency (100 Hz) repetitive conditioning electrical stimulation (CES, 10 min) on human somatosensory evoked potentials (SEPs) to evaluate if short-term cortical plasticity could be induced. METHODS: Painful electrical stimulations were applied to thumb (D1) and little finger (D5) fingertips, respectively. The 124-channel EEG was recorded from 10 healthy male volunteers. Peak stages around 34, 45, 212, 331 ms were analyzed with focal maximum amplitude (FA) and area magnitude (AM) of scalp field potential, topography, and equivalent current dipole source localisation, comparing before and after two-level CES (high- vs. low-level) applied to the He-Gu acupoint. RESULTS: After a high-level CES, the positive FA and AM of the current efflux showed a significant increase at the early phase 34 ms, and significantly decreased at 45 ms in D1 SEPs. The negative FA and AM of the current influx were significantly increased at late phase 350 ms of the D5 SEPs. Only 36 ms, the z-axis position of dipole was significantly changed from (x: -15.9 mm, y: 29.6 mm, z: 43.9 mm) to (x: -12.9 mm, y: 29.4mm, z: 51.5mm) for the D5 SEPs. CONCLUSIONS: The high-level CES significantly attenuated the subsequent cortical activation (45 ms peak for D1 stimulation). Both low- and high-level CES significantly enhanced the late activities (226, 350 ms) in D5 stimulation. This may be explained by pain sensation change at the level of subcortical cingulate cortex induced by the site-dependent post-effect of CES. SIGNIFICANCE: This study showed cortical plasticity induced by conditioning somatosensory stimulation. 相似文献
13.
Esophageal foreign body causing direct aortic injury. 总被引:4,自引:0,他引:4
Foreign bodies in the esophagus are uncommon causes of esophageal perforation. Many nonperforating cases are successfully managed by flexible gastroscopy. However, complicated foreign bodies such as those that result in esophageal perforation and vascular injury are best managed surgically. Gastroscopy remains the primary method of diagnosis. A case of a 59-year-old woman who developed retrosternal and intrascapular pain, odynophagia and hematemesis after eating fish is reported. Flexible gastroscopy showed arterial bleeding from the midthoracic esophagus. Computed tomography scan localized a 3 cm fish bone perforating the esophagus with surrounding hematoma. An aortogram did not reveal an actively bleeding aortoesophageal fistula. The fish bone was surgically removed and the patient recovered with no postoperative complications. This case illustrates the importance of early consideration for surgical intervention when confronted with a brisk arterial bleed from the esophagus with suggestive history of foreign body ingestion. 相似文献
14.
15.
P F Plouin D L Clement H Boccalon J Dormandy I Durand-Zaleski G Fowkes L Norgren T Brown 《International angiology》2003,22(4):333-339
Atherosclerotic renal artery stenosis (ARAS) may cause hypertension, progressive renal failure, and recurrent pulmonary edema. It typically occurs in high risk patients with coexistent vascular disease elsewhere. Most patients with ARAS are likely to die from coronary heart disease or stroke before end-stage renal failure occurs. Recent controlled trials have shown that most patients undergoing angioplasty to treat renovascular hypertension still need antihypertensive agents 6 or 12 months after the procedure. Nevertheless, the number of antihypertensive agents required to control blood pressure adequately is lower following angioplasty than for medication alone. Trials assessing the value of revascularization for preserving renal function or preventing clinical events are only in the early recruitment phase. Revascularization should be undertaken in patients with ARAS and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or with an increase in plasma creatinine levels during angiotensin-converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive, hypolipidemic and antiplatelet agents is necessary in almost all cases. 相似文献
16.
G. Kahlmeter D. F. J. Brown F. W. Goldstein A. P. MacGowan J. W. Mouton I. Odenholt A. Rodloff C-J. Soussy M. Steinbakk F. Soriano O. Stetsiouk 《Clinical microbiology and infection》2006,12(6):501-503
The main objectives of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) are to harmonise breakpoints for antimicrobial agents in Europe, and to act as the breakpoint committee for the European Medicines Agency (EMEA) during the registration of new antimicrobial agents. Detailed EUCAST procedures for harmonising and setting breakpoints for antimicrobial agents are available on the EUCAST website. Beginning with the current issue, a series of EUCAST Technical Notes will be published in CMI, based on the rationale documents produced by EUCAST for each of the antimicrobial agents studied, with the aim of highlighting important background information underlying decisions on breakpoints made by EUCAST. 相似文献
17.
Vascular malformation (AVM) in the gastrointestinal tract is an uncommon, but not rare, cause of bleeding and iron deficiency anemia, especially in an aging population. While endoscopic coagulative therapy is the method of choice for controlling bleeding, a substantial number of cases require additional therapy. Adjunctive or even primary phamacotherapy may be indicated in recurrent bleeding. However, there is little evidence-based proof of efficacy for any agent. The bulk of support is derived from anecdotal reports or case series. The present review compares the outcome of AVM after no intervention, coagulative therapy or focus on pharmacological agents. Most of the literature encompasses two common AVMs, angiodysplasia and hereditary hemorrhagic telangiectasia. Similarly, the bulk of information evaluates two therapies, hormones (estrogen and progesterone) and the somatostatin analogue octreotide. Of these, the former is the only therapy evaluated in randomized trials, and the results are conflicting without clear guidelines. The latter therapy has been reported only as case reports and case series without prospective trials. In addition, other anecdotally used medications are discussed. 相似文献
18.
19.
Frank G. Shellock Jerrold H. Mink Andrew L. Deutsch James Fox Todd Molnar Ronald Kvitne Richard Ferkel 《Journal of magnetic resonance imaging : JMRI》1994,4(4):590-594
The effect of a newly developed patellar realignment brace was evaluated in 21 patellofemoral joints (19 patients) with patellar subluxation (13 joints with lateral subluxation and eight with medial subluxation) by using active-movement, loaded kinematic magnetic resonance (MR) imaging. Sixteen patellofemoral joints (76%) demonstrated a qualitative correction of or improvement in patellar subluxation (ie, centralization of the patella or a decrease in the displacement of the patella) after application of the brace. Four of the five “failures” occurred in patellofemoral joints that had patella alta and/or dysplastic bone anatomy. These results indicate that the patellar realignment brace was able to counteract patellar subluxation in the majority of patellofemoral joints studied, as shown by active-movement, loaded kinematic MR imaging. This brace appears to be useful for conservative treatment of patients with patellofemoral joint pain secondary to patellar malalignment and maltracking. 相似文献
20.