全文获取类型
收费全文 | 3258篇 |
免费 | 147篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 30篇 |
妇产科学 | 32篇 |
基础医学 | 375篇 |
口腔科学 | 41篇 |
临床医学 | 302篇 |
内科学 | 649篇 |
皮肤病学 | 45篇 |
神经病学 | 489篇 |
特种医学 | 106篇 |
外科学 | 674篇 |
综合类 | 31篇 |
预防医学 | 142篇 |
眼科学 | 34篇 |
药学 | 228篇 |
中国医学 | 4篇 |
肿瘤学 | 205篇 |
出版年
2021年 | 34篇 |
2020年 | 24篇 |
2019年 | 26篇 |
2018年 | 34篇 |
2017年 | 40篇 |
2016年 | 42篇 |
2015年 | 49篇 |
2014年 | 76篇 |
2013年 | 114篇 |
2012年 | 167篇 |
2011年 | 168篇 |
2010年 | 96篇 |
2009年 | 80篇 |
2008年 | 140篇 |
2007年 | 134篇 |
2006年 | 146篇 |
2005年 | 151篇 |
2004年 | 149篇 |
2003年 | 151篇 |
2002年 | 116篇 |
2001年 | 155篇 |
2000年 | 130篇 |
1999年 | 134篇 |
1998年 | 43篇 |
1997年 | 47篇 |
1996年 | 25篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 18篇 |
1992年 | 61篇 |
1991年 | 48篇 |
1990年 | 52篇 |
1989年 | 58篇 |
1988年 | 44篇 |
1987年 | 42篇 |
1986年 | 46篇 |
1985年 | 40篇 |
1984年 | 26篇 |
1983年 | 21篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1979年 | 19篇 |
1978年 | 21篇 |
1977年 | 21篇 |
1976年 | 32篇 |
1975年 | 36篇 |
1974年 | 29篇 |
1973年 | 35篇 |
1972年 | 18篇 |
1971年 | 22篇 |
排序方式: 共有3422条查询结果,搜索用时 31 毫秒
31.
BACKGROUND: The indications for operative intervention for symptomatic hypertrophic obstructive cardiomyopathy (HOCM) in infancy and childhood are not well defined because of the rarity of the lesion. The traditional surgical procedure consists of septal myectomy. In an attempt to further improve the outcome of HOCM associated with concentric left ventricular hypertrophy and aortic valve disease in infancy, we have combined resection of the left ventricular septum and free wall with a Ross-Konno procedure. METHODS: Three infants (aged 3, 4, and 10 months) with HOCM (left ventricular aortic gradients of 75, 95, and 110 mmHg), associated concentric left ventricular hypertrophy, and valvar aortic stenosis (n = 1) or combined valvar aortic stenosis and regurgitation (n = 2) underwent extensive resection of fibroelastosis and subendocardial myocardium of the left ventricular septum and free wall in combination with a Ross-Konno operation. All three patients had marked systolic anterior motion of the mitral valve. The length of the incision into the ventricular septum was 1.8, 2.0, and 2.3 cm. RESULTS: In all three patients this procedure resulted in a marked reduction of width of the left ventricular septum (median 9 mm vs 14 mm preoperatively) and the left ventricular posterior free wall (median 8 mm vs 12 mm preoperatively) and an almost twofold increase of the left ventricular end-diastolic volume (median 13.5 cm3 vs 7.0 cm3 preoperatively). The neo-aortic valve functioned normally. Systolic anterior motion of the anterior leaflet of the mitral valve had completely resolved in two patients and had markedly regressed in the remaining patient. At follow-up of 15, 17, and 26 months, two patients had absence of a left ventricular outflow tract gradient and the third patient had a residual sub-valvar gradient of 15 mmHg. CONCLUSIONS: The reported procedure may be a valuable technique in severe forms of hypertrophic cardiomyopathy associated with aortic valve disease. The operation results in enlargement of the left ventricular stroke volume and improvement of the left ventricular diastolic function, restores aortic valve anatomy and function, and abolishes or decreases systolic anterior motion of the mitral valve. 相似文献
32.
Mohr H 《麻醉学,监护医学,急救医学,疼痛治疗》1999,34(12):773-775
33.
Rundek T Di Tullio MR Sciacca RR Titova IV Mohr JP Homma S Sacco RL 《Stroke; a journal of cerebral circulation》1999,30(12):2683-2686
BACKGROUND AND PURPOSE: Aortic arch atheromas (AAs) have been shown to be a risk factor for ischemic stroke (IS) in the elderly because of their potential for cerebral embolization. However, the association between AAs and the presence of cerebral microemboli has not been clearly established. The aim of this study was to determine whether large AAs are associated with an increased frequency of high-intensity transient signals (HITS) in elderly patients with IS. METHODS: We performed bitemporal simultaneous HITS monitoring of both middle cerebral arteries in 62 consecutive elderly patients with acute IS (mean age 72.5+/-8.8 years, 65% men). In 16 patients, one or both temporal windows were inadequate; therefore, the analysis of HITS was performed in the remaining 46 patients. All patients underwent omniplane transesophageal echocardiography (TEE), and they had no significant extracranial or intracranial artery disease and no cardiac prosthetic valves. Large AA was defined as > or = 4 mm in thickness. Complex AA was defined as ulcerated or mobile, regardless of plaque thickness. HITS monitoring was performed within 24 hours of TEE and analyzed by an experienced neurologist-sonographer blinded to TEE findings. A 9-dB threshold was chosen to discriminate HITS from background Doppler signal. The HITS counts in the left and in the right middle cerebral arteries were added and reported as a total number of HITS in 30 minutes. RESULTS: HITS were detected in 14 (78%) of 18 patients with large AAs versus 8 (29%) of 28 patients with no or small AAs (odds ratio [OR] 8.8, 95% CI 2.2 to 34.8; P=0. 001). The association was also present in 27 patients with no other cardiac embolic sources, such as atrial fibrillation, patent foramen ovale, spontaneous echo contrast, and thrombus (7 of 10 patients with large AAs versus 3 of 17 patients with small or no AA; OR 10.9, 95% CI 1.7 to 68.5; P=0.013). Complex AAs were associated with a higher frequency of HITS than were noncomplex AAs (6 of 6 patients with complex AAs versus 15 of 39 patients with noncomplex AAs; OR 2. 6, 95% CI 1.7 to 3.9; P=0.005). CONCLUSIONS: HITS are significantly associated with large AAs in elderly stroke patients. This observation may support the causal role of large AAs in IS. 相似文献
34.
B Grosche D Lackland L Mohr J Dunbar J Nicholas W Burkart D Hoel 《Journal of radiological protection》1999,19(3):243-252
In 1991, an increased rate of childhood leukaemia was reported from the small northern German community of Elbmarsch, which is located on the banks of the River Elbe opposite the Kruemmel nuclear power plant. Owing to the fact that the increase occurred six years after the start-up of the plant, radioactive discharges were suspected as being implicated in the development of the cases. Previous investigations have failed to identify any exposure which might be associated with the cluster. Nonetheless, concern regarding the increased tritium burden in the environment remains. To further assess the impact of tritium releases to the environment upon population cancer rates, the releases and leukaemia rates at the Savannah River site, USA, were compared with the Kruemmel site. Based on the data from 1991 to 1995, the incidence of childhood leukaemia in the vicinity of the Savannah River site was non-significantly less than expected compared with the significantly higher than expected rates close to the German plant. In contrast, tritium releases from the Savannah River site exceed those from the Kruemmel site by several orders of magnitude. The results of this observational study suggest that factors other than environmental tritium releases are associated with the increased number of leukaemia cases near the Kruemmel site. 相似文献
35.
36.
Employing the dopamine autoreceptor agonist (-)-3-PPP (3) as well as the cholinergic receptor ligands 4 and 5 as lead compounds the 3-pyrrolidinylisoxazoles 2a,b as well as its optical antipodes ent 2a,b were synthesized from (R)-aspartic acid (6) and (S)-aspartic acid (ent-6), respectively. Pharmacological properties of the target compounds were evaluated employing dopamine D2 receptor binding studies and functional experiments on muscarinic M2 receptors. 相似文献
37.
目的:探讨人脑肿瘤p53表达与对亚硝脲类抗癌药耐药的关系。方法:采用WesternBlot分析,对10株人脑肿瘤细胞的p53、ERCC2表达进行检测,并与肿瘤对二氯乙基亚硝脲(BCNU)及二氯乙基肉芥子亚硝脲(SarCNU)耐药性进行比较。结果:ERCC2表达与肿瘤对BCNU和SarCNU耐药相关。p53与BCNU和SarCNU耐药相关。多元回归分析,ERCC2+p53与BCNU和SarCNU间的相关性明显提高。结论:ERCC2和p53基因表达在人脑肿瘤对亚硝脲类抗癌药耐药中起重要作用。 相似文献
38.
F. Mohr W. Hubmann W. Bender S. Hönicke Ch. Wahlheim R. Cohen C. Haslacher R. Schlenker P. Werther 《European archives of psychiatry and clinical neuroscience》1996,246(5):240-248
A German version of the Neurological Evaluation Scale (NES) was administered to 143 schizophrenic patients, 45 of them being severly chronic and disabled. Seventy-eight alcohol-dependent inpatients and 57 healthy volunteers were tested as control groups. Neurological soft signs (NSS) were rated with convincing agreement. Schizophrenic patients are more impaired on all scales than healthy controls. The chronic, severly disabled schizophrenic patients are more impaired compared with the main group of schizophrenic patients and both control groups. A significant patients and alcohol-dependent patients was only found for the subscale Motor Coordination. Compared with healthy controls the alcohol-dependent patients show a higher NES total score. The NES total score was related to the relative width of the third ventricle. Total score and subscales were correlated consistently with the level of cognitive functioning as measured by the Raven Standard Progressive Matrices and various neuropsychological tests presumably sensitive to dysfunctions of the prefrontal cortex. The NSS were related to positive as well as to negative symptoms, the correlations with negative symptoms being confined to items of Cognitive Disorganization. This close association of psychomotor and cognitive dysfunctions may be seen as related to the frequently discussed dysfunctions of the prefrontal cortex or the neurointegrative deficit postulated by Meehl. 相似文献
39.
40.