全文获取类型
收费全文 | 25108篇 |
免费 | 2146篇 |
国内免费 | 101篇 |
专业分类
耳鼻咽喉 | 364篇 |
儿科学 | 683篇 |
妇产科学 | 461篇 |
基础医学 | 2649篇 |
口腔科学 | 337篇 |
临床医学 | 3019篇 |
内科学 | 5858篇 |
皮肤病学 | 720篇 |
神经病学 | 2773篇 |
特种医学 | 853篇 |
外科学 | 3595篇 |
综合类 | 322篇 |
现状与发展 | 2篇 |
一般理论 | 18篇 |
预防医学 | 2327篇 |
眼科学 | 562篇 |
药学 | 1442篇 |
中国医学 | 25篇 |
肿瘤学 | 1345篇 |
出版年
2023年 | 211篇 |
2022年 | 225篇 |
2021年 | 558篇 |
2020年 | 412篇 |
2019年 | 488篇 |
2018年 | 714篇 |
2017年 | 550篇 |
2016年 | 591篇 |
2015年 | 656篇 |
2014年 | 955篇 |
2013年 | 1266篇 |
2012年 | 1580篇 |
2011年 | 1649篇 |
2010年 | 1014篇 |
2009年 | 1095篇 |
2008年 | 1488篇 |
2007年 | 1548篇 |
2006年 | 1505篇 |
2005年 | 1421篇 |
2004年 | 1395篇 |
2003年 | 1242篇 |
2002年 | 1106篇 |
2001年 | 353篇 |
2000年 | 279篇 |
1999年 | 359篇 |
1998年 | 353篇 |
1997年 | 311篇 |
1996年 | 288篇 |
1995年 | 281篇 |
1994年 | 218篇 |
1993年 | 183篇 |
1992年 | 218篇 |
1991年 | 177篇 |
1990年 | 153篇 |
1989年 | 205篇 |
1988年 | 155篇 |
1987年 | 141篇 |
1986年 | 157篇 |
1985年 | 157篇 |
1984年 | 153篇 |
1983年 | 111篇 |
1982年 | 136篇 |
1981年 | 141篇 |
1980年 | 108篇 |
1979年 | 101篇 |
1978年 | 93篇 |
1977年 | 93篇 |
1976年 | 66篇 |
1975年 | 75篇 |
1971年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
K M McIntyre J A Vita C T Lambrew J Freeman J Loscalzo 《The New England journal of medicine》1992,327(24):1715-1720
BACKGROUND. The noninvasive prediction of pulmonary-capillary wedge pressure (PCWP) is important for the recognition and treatment of a variety of cardiovascular disorders. The response of the arterial pressure to the Valsalva maneuver has been shown to correlate with the PCWP. We therefore devised a noninvasive method to measure this pressure response at the bedside and correlated these measurements with the PCWP measured directly with a pulmonary-artery catheter. METHODS. Simultaneous, blinded, noninvasive measurements of the ratio of the final amplitude to the initial amplitude of the pulse wave form during the stress phase of the Valsalva maneuver (pulse-amplitude ratio) and direct measurements of the PCWP were obtained in 20 clinically stable patients and in 14 clinically unstable patients who were receiving vasoactive agents, 12 of whom also had endotracheal tubes in place. RESULTS. Using linear regression analysis, we found that the pulse-amplitude ratio strongly correlated with the measured PCWP over a range of base-line values from 4 to 32 mm Hg for the 20 clinically stable patients (R2 = 0.80) and the 14 clinically unstable patients (R2 = 0.85). The method also correctly predicted changes in the PCWP after the administration of nitroglycerin or furosemide and after expansion of the intravascular volume (R2 = 0.79). CONCLUSIONS. These preliminary data indicate that a simple noninvasive method can accurately predict the PCWP and changes in the PCWP in response to medical therapy. 相似文献
102.
103.
A Halldorsson G C Hunter K E McIntyre V M Bernhard 《The Journal of cardiovascular surgery》1991,32(3):376-379
We have recently treated a patient with an arteriovenous fistula that developed after a right internal jugular vein catheterization. The patient was found to have a pulsatile hematoma and a bruit five days after removal of a temporary pacemaker catheter. Digital subtraction arteriography documented a fistula between the right internal mammary artery and subclavian vein. The fistula was surgically repaired via the cervical route. To our knowledge, an arteriovenous fistula between the internal mammary artery and subclavian vein has not been previously described as a complication of a percutaneous internal jugular vein catheterization. 相似文献
104.
W. G. Selley FDS Hon FCST R. E. Ellis MPhil F. C. Flack PhD C. R. Bayliss MB B Chir FRCR V. R. Pearce MB FRCP 《Dysphagia》1994,9(3):162-167
Simultaneous recording of adult subjects sipping small amounts of fluid from a cup have been obtained by videofluoroscopy together with feeding respiratory patterns and swallow sounds from the Exeter Dysphagia Assessment Technique (EDAT). These allowed visual representations of respiration and swallow sounds to be superimposed on a videofluoroscopy recording using a split-screen technique. Sequentially numbered, 1/50 sec, half-frame photographic prints were examined and schematic drawings of the relevant radiographs were made. These were superimposed on to the actual EDAT printed chart of the same swallow event, theri exact time relationship with respiration and cervical swallow sounds being preserved. The results allow events in the barium videofluoroscopy to be related to events in the feeding respiratory pattern and swallow sounds recorded by EDAT. 相似文献
105.
David Salonen M.D. FRCP Donald Resnick M.D. Sabina M. Valentine 《Skeletal radiology》1994,23(6):454-454
106.
107.
Grant R. Caddy MD MRCP Consultant Gastroenterologist Tony C.K. Tham MD FRCP Consultant Gastroenterologist 《Best Practice & Research: Clinical Gastroenterology》2006,20(6):1085
Symptomatic BDS commonly cause significant morbidity and attempt at stone removal should be attempted if possible. Complications of CBDS include biliary colic, jaundice, cholangitis and pancreatitis. Investigations aimed to predict the presence of stones within the bile duct include serum bilirubin, AST, ALP, common bile duct diameter and age as independent predictors of choledocholithiasis. TUS is a sensitive test in detecting bile duct dilatation but the sensitivity is reduced in its ability to detect choledocholithiasis. A NIH consensus statement found that ERC, MRC and EUS were comparable in their sensitivities, specificities and accuracy rates for detection of choledocholithiasis. ERC and stone removal using a balloon or basket is often performed following EST. EBD may be performed if patients have uncorrected coagulopathies but the risk of pancreatitis is higher than for EST (although the risk of bleeding complications is lower for EBD). ML is often required in difficult to remove CBDS and using this device, CBDS can be removed in 90–95% of cases. Other forms of lithotripsy including laser lithotripsy and EHL are confined to specialised centres and the evidence for their use is based on small studies. ESWL may clear stones from the bile duct in up to 93% of patients but frequently ERC and stone fragment removal is required post ESWL. The role of medical therapy in difficult to remove CBDS (or in CBDS in patients with severe co-morbid illness preventing ERC + stone removal) is still currently uncertain due to a lack of large randomised control trials. 相似文献
108.
Serial angiographic follow-up of sirolimus-eluting stents for unprotected left main coronary artery revascularization. 总被引:4,自引:0,他引:4
Matthew J Price Ecaterina Cristea Neil Sawhney John A Kao Jeffrey W Moses Martin B Leon Ricardo A Costa Alexandra J Lansky Paul S Teirstein 《Journal of the American College of Cardiology》2006,47(4):871-877
OBJECTIVES: This study was performed to evaluate the clinical and serial angiographic outcomes of patients undergoing sirolimus-eluting stent (SES) implantation for unprotected left main coronary artery (LMCA) stenosis. BACKGROUND: The efficacy of SES has led to their expanded use for off-label indications, including LMCA disease. METHODS: Unprotected LMCA intervention with SES was attempted in 50 patients. Surveillance angiography was performed at three and nine months' follow-up. RESULTS: The target lesion involved the distal LMCA in 47 patients (94%). In-lesion restenosis occurred in 21 patients (42%), was focal in 85% of cases, and in 82% involved the branch ostia, sparing the LMCA itself. Target lesion revascularization (TLR) occurred in 19 patients (38%) over a mean follow-up of 276 +/- 57 days; TLR was ischemia-driven in 7 patients (14%). Late loss was significantly greater within the left circumflex (LCX) ostium compared to the parent vessel (PV) of the LMCA bifurcation (0.83 +/- 0.89 mm vs. 0.49 +/- 0.72 mm, p = 0.04). Late loss continued to increase between three- and nine-month follow-up. Final minimal luminal diameter and maximal balloon pressure were independent predictors of restenosis of the PV. CONCLUSIONS: Restenosis is a frequent finding when serial angiographic follow-up is performed after SES implantation for unprotected distal LMCA lesions. Restenosis is usually focal, most often involves the LCX ostium, and often occurs without symptoms. 相似文献
109.
110.
Matthew A Roberts Merlin C Thomas Dharsh Fernando Neil Macmillan David A Power Francesco L Ierino 《Nephrology, dialysis, transplantation》2006,21(6):1611-1617
BACKGROUND: Advanced glycation end products (AGEs) have biological properties that may contribute to the premature cardiovascular mortality of haemodialysis patients. This study examines the hypothesis that low molecular weight forms of fluorescent AGEs (LMW fluorescence) predict mortality in haemodialysis patients. METHODS: The LMW fluorescence was measured in 85 patients treated with chronic haemodialysis and prospectively followed for 4 years. The primary outcome of all-cause mortality was assessed using Cox proportional hazards regression model. RESULTS: At the end of the follow-up period 37 (44%) patients died. The median LMW fluorescence level was 24.2 arbitrary units (range: 10.6-148.1 AU) and the receiver operator characteristic (ROC) curve cut-off for mortality was 37.0 AU. The LMW fluorescence predicted death both as a binary variable at the ROC cut-off, and as a continuous log-transformed variable when adjusted for age, albumin and C-reactive protein (CRP). Adjusted for age, albumin and CRP, the hazard ratio for mortality was 3.05 (1.41-6.60, P = 0.005) for LMW fluorescence as a binary variable and 2.71 per log unit (1.37-5.38, P = 0.004) as a continuous log-transformed variable. CONCLUSION: The low molecular weight forms of AGEs predict mortality in patients receiving chronic haemodialysis, and may be important in the mechanisms leading to atherosclerosis and inflammation in such patients. 相似文献