全文获取类型
收费全文 | 15212篇 |
免费 | 983篇 |
国内免费 | 88篇 |
专业分类
耳鼻咽喉 | 156篇 |
儿科学 | 285篇 |
妇产科学 | 258篇 |
基础医学 | 2047篇 |
口腔科学 | 154篇 |
临床医学 | 1351篇 |
内科学 | 3663篇 |
皮肤病学 | 270篇 |
神经病学 | 1617篇 |
特种医学 | 707篇 |
外科学 | 2668篇 |
综合类 | 32篇 |
一般理论 | 2篇 |
预防医学 | 676篇 |
眼科学 | 138篇 |
药学 | 1021篇 |
中国医学 | 19篇 |
肿瘤学 | 1219篇 |
出版年
2024年 | 12篇 |
2023年 | 108篇 |
2022年 | 171篇 |
2021年 | 471篇 |
2020年 | 224篇 |
2019年 | 455篇 |
2018年 | 537篇 |
2017年 | 357篇 |
2016年 | 361篇 |
2015年 | 444篇 |
2014年 | 691篇 |
2013年 | 802篇 |
2012年 | 1282篇 |
2011年 | 1316篇 |
2010年 | 732篇 |
2009年 | 706篇 |
2008年 | 1062篇 |
2007年 | 1006篇 |
2006年 | 1022篇 |
2005年 | 903篇 |
2004年 | 865篇 |
2003年 | 711篇 |
2002年 | 688篇 |
2001年 | 131篇 |
2000年 | 96篇 |
1999年 | 123篇 |
1998年 | 124篇 |
1997年 | 111篇 |
1996年 | 84篇 |
1995年 | 76篇 |
1994年 | 68篇 |
1993年 | 45篇 |
1992年 | 57篇 |
1991年 | 41篇 |
1990年 | 35篇 |
1989年 | 44篇 |
1988年 | 45篇 |
1987年 | 32篇 |
1986年 | 28篇 |
1985年 | 22篇 |
1984年 | 18篇 |
1983年 | 18篇 |
1982年 | 14篇 |
1975年 | 14篇 |
1974年 | 14篇 |
1972年 | 13篇 |
1971年 | 13篇 |
1970年 | 18篇 |
1969年 | 14篇 |
1968年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Pericardial puncture is the percutaneous insertion of a needle into the pericardial space to drain a pathological pericardial effusion. The challenge for the operating surgeon is to reach percutaneously a target zone in the vicinity of the mobile heart, in a soft-tissue environment. The surgeon's ability to accomplish this depends on his own mental picture of the effusion. CASPER is a navigation software using an optical localizer which assists the surgeon by enhancing the representation of the effusion and guiding the needle's progress. Using a localized and calibrated echographic probe, the surgeon acquires a set of images in the region of interest. This zone is then manually segmented on each image, a common zone is computed, and the surgeon defines a trajectory for the needle. During the puncture procedure, the surgeon follows the position of the localized needle on a computer monitor. After initial validation on an experimental phantom, a feasibility study was performed using canine and porcine models. The optical localization device was changed from an Optotrak to a Polaris device for easier use in the clinical setting. Prior to clinical application, various tests were performed concerning the mobility of the thoracic cage, the reproducibility of the thoracic position over several apneas, and the stability of anatomic structures relative to the thoracic cage. Finally, a first clinical application was successfully performed using this system. The present paper reports on these last two stages. 相似文献
22.
23.
Edgardo Pezzetta Alexandre Paroz Hans-Beat Ris Olivier Martinet 《European journal of cardio-thoracic surgery》2003,23(6):1062-1064
Spontaneous hemothorax is a rare and life threatening complication of neurofibromatosis. Two types of vascular involvement have been described: (a) stenotic or aneurysmal alterations in large vessels such as the aorta and its branches; and (b) dysplastic features in smaller vessels. Thoracotomy and surgical ligation of the bleeding vessels is primarily indicated in the presence of active bleeding with associated hemodynamic compromise. A more conservative approach with endovascular embolization or non-operative management have also been reported in case of hemodynamic stability. We present a rare case of spontaneous hemothorax treated conservatively in a patient with von Recklinghausen's disease. 相似文献
24.
25.
Behavioural pharmacology of the serenic, eltoprazine 总被引:1,自引:0,他引:1
In this paper the effects of serenics (eltoprazine and fluprazine) are described in several animal models for offensive agonistic, defensive agonistic and predatory behaviour. They are compared with the effects of a number of other putative anti-aggressive compounds or drugs used clinically in order to ameliorate aggressive behaviour of psychiatric patients. In isolation-induced offensive aggression in mice, eltoprazine has a marked and potent anti-aggressive activity, although numerous other psychoactive drugs also exert anti-aggressive effects. The behavioural specificity of this anti-aggressive profile was investigated using an ethologically derived animal model, social interaction in male mice. In this model, eltoprazine has a very specific anti-aggressive (serenic) profile, inhibiting aggression while social interaction and exploration are not decreased but even enhanced; inactivity, a measure for sedation, is not affected. Such a profile contrasts sharply with that of neuroleptics (chlorpromazine, haloperidol), psychostimulants (d-amphetamine) or benzodiazepines (chlordiazepoxide), which exert severe sedation (neuroleptics) or even aggression-enhancing effects (BDZ). After subchronic treatment no tolerance for the anti-aggressive effects of eltoprazine occurred. The specific anti-aggressive effects of eltoprazine were also found in rat models of offensive agonistic behaviour. In one such model - resident-intruder aggression - eltoprazine reduced offensive behaviour specifically, leaving social interactions and exploration intact, and did not induce sedation or other unwanted side-effects. The neuroleptic haloperidol was very sedative in this model, as was the 5-HT1A-agonist buspirone. Benzodiazepines (chlordiazepoxide) have a biphasic effect in this paradigm, enhancing offence at low doses and decreasing it at higher doses, due to muscle relaxation. In another offensive model, colony-aggression, in which a dominant and subordinate male in a colony are confronted with a male intruder, eltoprazine reduced offensive behaviour of both the dominant and the subordinate against the intruder. In contrast, chlordiazepoxide enhanced aggression, at least at lower doses, whereas alcohol had, up to very high doses, no effect on the offensive behaviour. In a brain-stimulation induced offensive model--hypothalamically-induced aggression in rats--eltoprazine specifically reduces offence. Locomotion, a measure for sedation, was either unaffected or even somewhat enhanced, indicating the absence of any sedatory activity of this serenic compound. In contrast, haloperidol heavily sedated animals, making them incapable of aggression.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
26.
The distribution of the alpha 6 subunit of the GABAA receptor has been established in rat cerebellum and compared to the distribution of the alpha 1 (cat) and the beta 2/3 (rat, cat) subunits, using immunocytochemistry. The synapses established by Golgi cell terminals on the dendrites of granule cells were immunoreactive for the alpha 6, alpha 1 and beta 2/3 subunits in virtually all glomeruli, indicating that two variants (alpha 1 and alpha 6) of the same subunit are co-localized at the same synapses. The somatic membranes of the granule cells, which receive no synapses, were immunopositive for the alpha 1 and beta 2/3 subunits, but not for the alpha 6 subunit. Thus, the alpha 1 and the beta 2/3 subunits are located at both synaptic and extrasynaptic sites, but the alpha 6 subunit is detectable only at synaptic sites. 相似文献
27.
Cardiac MIBG scintigraphy is a sensitive tool for detecting cardiac sympathetic denervation in Parkinson's disease. 总被引:5,自引:0,他引:5
Frédéric Courbon Christine Brefel-Courbon Claire Thalamas Marie-Jeanne Alibelli Isabelle Berry Jean-Louis Montastruc Olivier Rascol Jean-Michel Senard 《Movement disorders》2003,18(8):890-897
[(123)I]Metaiodobenzylguanidine ([(123)I]MIBG) cardiac scintigraphy could be helpful to differentiate Parkinson's disease (PD) from multiple system atrophy (MSA), demonstrating that, in PD with autonomic failure but not in MSA, there is a myocardial postganglionic sympathetic dysfunction. To investigate whether this method is more sensitive than standard autonomic testing to detect early involvement of sympathetic cardiac efferent, we analyse MIBG myocardial uptake in 8 PD patients with normal autonomic testing (nondysautonomia PD group, NDPD) in comparison with 10 PD patients with abnormal autonomic testing (dysautonomia PD group, DPD) and 10 MSA patients. Global MIBG uptake was assessed using the ratio of [(123)I]MIBG uptake in the heart to the upper mediastinum (H/M) on planar scintigraphic data. Regional MIBG uptake was determined on two single photon emission tomography scans in regions of the left ventricle. The mean H/M ratios were significantly different among the three groups (P < 0.0001). H/M ratios of both NDPD and DPD patients groups (H/M = 1.83 +/- 0.50 and 1.24 +/- 0.40, respectively) were significantly lower than in MSA patients (H/M = 2.52 +/- 0.60). However, in NDPD patients, H/M was significantly higher than in DPD patients. When compared to MSA patients, NDPD patients showed a regional reduction in MIBG uptake in all left ventricle regions markedly in the apex and the inferior wall. Our results suggest that MIBG myocardial scintigraphy (analysis of both H/M ratio and regional MIBG uptake) may be more sensitive than standard autonomic testing for the early detection of silent autonomic dysfunction in PD. 相似文献
28.
Stuart Gherini Andre Lopez Lysiane Juberthie Jean Clatude Olivier 《Indian journal of otolaryngology and head and neck surgery》1994,46(2):50-62
The aim of surgical treatment of a fixed stapes is to restore an as effective as possible impedance transfer of the ossicular chain and acoustic impedance of the annular ligament of the footplate, when it has lost elasticity, and this in order to achieve the best possible physiological vibration of the inner ear fluids. 相似文献
29.
30.
A case of severe Guillain-Barré syndrome (GBS) was treated with high dose intravenous immunoglobulin (IVIG), 400 mg.kg-1.days-1, over three consecutive days. The treatment was repeated once. We observed a time-related response between immunoglobulins administration and clinical improvement. The pathologic lesions of the GBS suggest that this syndrome has an immunologic basis: a humoral factor is probably not the only immunological mechanism and cellular mechanisms are also likely to be of importance. Specific mechanisms might also be present in GBS, such as anti-idiotypic suppression of autoantibodies, and elimination of circulating immune complexes. Treatment with IVIG might have several therapeutic advantages over plasmapheresis: IVIG is easily infused without any delay, is easily available and has been used widely without serious complications. 相似文献