全文获取类型
收费全文 | 2071篇 |
免费 | 159篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 158篇 |
妇产科学 | 35篇 |
基础医学 | 185篇 |
口腔科学 | 34篇 |
临床医学 | 166篇 |
内科学 | 577篇 |
皮肤病学 | 30篇 |
神经病学 | 74篇 |
特种医学 | 270篇 |
外科学 | 148篇 |
综合类 | 45篇 |
一般理论 | 2篇 |
预防医学 | 189篇 |
眼科学 | 11篇 |
药学 | 191篇 |
中国医学 | 5篇 |
肿瘤学 | 110篇 |
出版年
2023年 | 14篇 |
2022年 | 9篇 |
2021年 | 16篇 |
2020年 | 20篇 |
2019年 | 19篇 |
2018年 | 32篇 |
2017年 | 28篇 |
2016年 | 30篇 |
2015年 | 32篇 |
2014年 | 52篇 |
2013年 | 60篇 |
2012年 | 72篇 |
2011年 | 63篇 |
2010年 | 79篇 |
2009年 | 68篇 |
2008年 | 79篇 |
2007年 | 71篇 |
2006年 | 77篇 |
2005年 | 62篇 |
2004年 | 58篇 |
2003年 | 67篇 |
2002年 | 42篇 |
2001年 | 55篇 |
2000年 | 43篇 |
1999年 | 53篇 |
1998年 | 67篇 |
1997年 | 80篇 |
1996年 | 64篇 |
1995年 | 52篇 |
1994年 | 70篇 |
1993年 | 60篇 |
1992年 | 39篇 |
1991年 | 37篇 |
1990年 | 33篇 |
1989年 | 59篇 |
1988年 | 69篇 |
1987年 | 57篇 |
1986年 | 56篇 |
1985年 | 41篇 |
1984年 | 29篇 |
1983年 | 33篇 |
1982年 | 24篇 |
1981年 | 23篇 |
1980年 | 27篇 |
1979年 | 18篇 |
1978年 | 17篇 |
1977年 | 17篇 |
1976年 | 14篇 |
1975年 | 20篇 |
1974年 | 6篇 |
排序方式: 共有2236条查询结果,搜索用时 15 毫秒
11.
We have recently treated two patients with closed pronation-external rotation bimalleolar ankle fractures. During the surgical explorations, an avulsion type rupture of the posterior tibial tendon was observed. Open reduction and internal fixation of the fracture in conjunction with primary tendon repair has produced excellent clinical results. We wish to report these two cases of this uncommon injury. More important, we wish to point out the association of the tendon rupture in conjunction with a particular type of fracture pattern. 相似文献
12.
13.
Hodgkin disease: CT of the thymus 总被引:2,自引:0,他引:2
The computed tomography (CT) scans in two groups of patients with Hodgkin disease were reviewed to determine the frequency of thymic enlargement. In 50 CT scans from 50 patients with evidence of thoracic disease on CT scans who were examined for primary staging, the thymus was enlarged in 15 of 50 (30%). Fifty CT scans were obtained from 44 patients at the time of 50 separate episodes of known or suspected relapse. Relapse occurred in the mediastinum in 12 episodes, lung parenchyma in five, and both sites in one. Thymic enlargement thought to be due to involvement by disease was present in seven of 18 (38%). Mediastinal disease was associated with thymic enlargement in all but one patient in whom a thymic cyst developed after radiation therapy. Differentiation of thymic enlargement from enlarged superior mediastinal lymph nodes was easily made in all but two patients. Thymic enlargement in the absence of lymph node enlargement may indicate a different disease, since isolated Hodgkin disease of the thymus is uncommon. Primary thymic tumor should be considered initially, whereas after treatment, rebound hyperplasia of the thymus may be the cause of enlargement. 相似文献
14.
Solitary bronchioloalveolar carcinoma: CT criteria 总被引:14,自引:0,他引:14
Kuhlman JE; Fishman EK; Kuhajda FP; Meziane MM; Khouri NF; Zerhouni EA; Siegelman SS 《Radiology》1988,167(2):379-382
The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis. 相似文献
15.
A randomized controlled trial of electromagnetic therapy in the primary care management of venous leg ulceration 总被引:1,自引:1,他引:0
OBJECTIVE: The aim was to establish the potential efficacy, tolerabilityand side-effect profile of electromagnetic therapy as an adjunctto conventional dressings in the treatment of venous leg ulcers. METHOD: A prospective, randomized, double blind controlled clinicaltrial was carried out in a dedicated leg ulcer clinic basedin one urban general practice. Nineteen patients with leg ulcersof confirmed venous aetiology were assessed. The main outcomemeasures were rate and scale of venous leg ulcer healing, changesin patient-reported pain levels, quality of life, degree ofmobility, side effect profile and acceptability to patientsand staff. RESULTS: Sixty-eight per cent of patients attending this dedicated clinicachieved improvements in the size of their ulcer (4, 21%, healedfully) and in reduced pain levels (P < 0.05) during the trial,despite the chronicity of ulcer histories. Patients treatedwith electromagnetic therapy at 800 Hz were found at day 50to have significantly greater healing (P < 0.05) and paincontrol (P < 0.05) than placebo therapy or treatment with600 Hz. All patients reported improved mobility at the end ofthe study. The electromagnetic therapy was well tolerated bypatients, with no differences between groups in reporting adverseevents, and proved acceptable to staff. CONCLUSION: Despite the small numbers in this pilot study, electromagnetictherapy provided significant gains in the healing of venousleg ulcers and reduction in pain. Keywords. Electromagnetic therapy, RCT, leg ulcers, primary care. 相似文献
16.
17.
Summary An infant with pulmonary arteriovenous fistulas is described. Surgical ligation of the fistulas and limited resection of paraenchyma from the right lung was followed at 11 months of age, by successful steel coil embolization of residual fistulas. 相似文献
18.
19.
Balloon dilation of the aortic valve: studies in normal lambs and in children with aortic stenosis 总被引:2,自引:0,他引:2
H Helgason J F Keane K E Fellows T J Kulik J E Lock 《Journal of the American College of Cardiology》1987,9(4):816-822
To evaluate the risks of and optimal method for valve dilation in aortic stenosis, balloons of different sizes were used to dilate the normal aortic root in 16 lambs and then stenotic valves in 15 children. In the lambs, inflated balloon to aortic anulus diameter ratios ranged from 0.9 to 1.5. These hearts were examined immediately after the procedure. Ratios of 0.9 to 1.1 did not produce significant damage to the left ventricular outflow tract, whereas those of 1.2 to 1.5 produced tears or hematomas, or both, of the aortic valve leaflets (n = 3), mitral valve leaflets (n = 4) and interventricular septum (n = 4). The 15 patients, aged 10 days to 15 years, underwent 16 balloon aortic valvotomy procedures. The balloon-aortic anulus ratio ranged from 0.67 to 1.1 (mean 0.90). The average pressure gradient decreased 69% and, overall, the peak systolic gradient decreased from 86 +/- 21 to 28 +/- 14 mm Hg (p less than 0.01) and the aortic valve area increased from 0.44 +/- 0.11 to 0.73 +/- 0.22 cm2/m2 (p less than 0.01). Immediately after the procedure an increase in aortic regurgitation was noted in 8 (57%) of 14 patients, but was never greater than 3+ and has been well tolerated. Other early complications encountered consisted of transient left bundle branch block in two patients, temporary femoral artery occlusion in three and femoral artery rupture requiring operative management in one infant. Balloon valvotomy can reduce the transvalvular gradient in most patients with valvular aortic stenosis when a balloon less than 1.1 times the aortic root diameter is used.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
20.
Recent studies have shown that tetrafluoroethylene is a renal and hepatic carcinogen in the rat. In this study, we have examined
the ability of a single i.p. dose of 1,1,2,2-tetrafluoroethyl-l-cysteine (TFEC), a major metabolite of tetrafluoroethylene, to produce hepatic and renal injury in male and female rats.
We have also examined the effect of blocking the renal organic anion transport system with probenecid and of inhibiting the
activity of cysteine conjugate β-lyase with aminooxyacetic acid on the extent of renal injury produced by TFEC. Doses of ≥12.5 mg/kg
TFEC produced renal tubular necrosis to the pars recta of the proximal tubules within 24 h in both male and female rats. This
was associated with an increased kidney to body weight ratio and plasma urea at doses of ≥25 mg/kg. No consistent evidence
of liver injury was seen at doses up to 50 mg/kg TFEC in rats of either sex, although occasional vacuolation of hepatocytes
and a small dose-related increase in liver to body weight ratio was observed. Prior treatment of female rats with probenecid
completely prevented the renal injury produced by either 25 or 50 mg/kg TFEC as judged by plasma urea and histopathology.
However, prior treatment of female rats with aminooxyacetic acid afforded no protection against the nephrotoxicity produced
by either TFEC or the cysteine conjugate of hexachloro-1,3-butadiene. Thus no major sex difference in nephrotoxicity in the
rat was seen with TFEC, while accumulation of TFEC, or its N-acetyl derived metabolite, into renal proximal tubular cells
via a probenecid sensitive transport system appears to be a key event in the mechanism of nephrotoxicity. The lack of protection
observed with the cysteine conjugate β-lyase inhibitor, aminooxyacetic acid, may reflect the inability to completely inhibit
the mitochondrial form of this enzyme and thereby prevent the formation of the reactive metabolite. Our acute studies provide
no insight concerning the liver carcinogenicity of tetrafluoroethylene.
Received: 8 December 1997 / Accepted: 3 February 1998 相似文献