全文获取类型
收费全文 | 55146篇 |
免费 | 3691篇 |
国内免费 | 252篇 |
专业分类
耳鼻咽喉 | 553篇 |
儿科学 | 1194篇 |
妇产科学 | 825篇 |
基础医学 | 7272篇 |
口腔科学 | 1229篇 |
临床医学 | 5803篇 |
内科学 | 12146篇 |
皮肤病学 | 1107篇 |
神经病学 | 6274篇 |
特种医学 | 2670篇 |
外国民族医学 | 1篇 |
外科学 | 9268篇 |
综合类 | 331篇 |
一般理论 | 17篇 |
预防医学 | 2647篇 |
眼科学 | 782篇 |
药学 | 3222篇 |
1篇 | |
中国医学 | 75篇 |
肿瘤学 | 3672篇 |
出版年
2023年 | 446篇 |
2022年 | 734篇 |
2021年 | 1491篇 |
2020年 | 902篇 |
2019年 | 1347篇 |
2018年 | 1536篇 |
2017年 | 1196篇 |
2016年 | 1460篇 |
2015年 | 1646篇 |
2014年 | 2110篇 |
2013年 | 2582篇 |
2012年 | 4168篇 |
2011年 | 4215篇 |
2010年 | 2495篇 |
2009年 | 2263篇 |
2008年 | 3617篇 |
2007年 | 3728篇 |
2006年 | 3439篇 |
2005年 | 3425篇 |
2004年 | 3062篇 |
2003年 | 2940篇 |
2002年 | 2663篇 |
2001年 | 683篇 |
2000年 | 590篇 |
1999年 | 614篇 |
1998年 | 566篇 |
1997年 | 449篇 |
1996年 | 360篇 |
1995年 | 312篇 |
1994年 | 279篇 |
1993年 | 212篇 |
1992年 | 261篇 |
1991年 | 249篇 |
1990年 | 206篇 |
1989年 | 211篇 |
1988年 | 179篇 |
1987年 | 146篇 |
1986年 | 168篇 |
1985年 | 143篇 |
1984年 | 185篇 |
1983年 | 140篇 |
1982年 | 114篇 |
1981年 | 88篇 |
1980年 | 86篇 |
1979年 | 114篇 |
1978年 | 96篇 |
1977年 | 82篇 |
1976年 | 82篇 |
1975年 | 84篇 |
1974年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Eva Maria Valesky Diamant Thai Markus Meissner Christian Beier Manfred Wolter Helmut Schfer Roland Kaufmann 《Journal der Deutschen Dermatologischen Gesellschaft》2007,5(9):770-772
With 1–1.5 million cases reported every year cutaneous leishmaniasis represents an increasing health problem. The course of cutaneous leishmaniasis varies from a single self‐healing ulcer to a persistent ulcer or progressive mucosal disease with nasopharyngeal destruction. An enormous array of topical and systemic treatment modalities has been endorsed. The response to treatment depends on the species of parasite as well as the host's immunological and genetic status. Species‐specific treatment guidelines based on evidence from controlled studies are highly desirable. We present two cases of cutaneous leishmaniasis, one in a child and one during pregnancy, reviewing various diagnostic and therapeutic measures with special attention to problems in young and pregnant patients. 相似文献
52.
53.
Ulrich Weber Christian WA Pfirrmann Rudolf O Kissling Juerg Hodler Marco Zanetti 《BMC musculoskeletal disorders》2007,8(1):20
Background
Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis. 相似文献54.
Max Heiland Philipp Pohlenz Marco Blessmann Christian R Habermann Lars Oesterhelweg Philipp C Begemann Christian Schmidgunst Felix A S Blake Klaus Püschel Rainer Schmelzle Dirk Schulze 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(6):814-820
OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner. 相似文献
55.
56.
Development of the central nervous system (CNS) involves the transformation of a two-dimensional epithelial sheet of uniform ectodermal cells, the neuroectoderm, into a highly complex three-dimensional structure consisting of a huge variety of different neural cell types. Characteristic numbers of each cell type become arranged in reproducible spatial patterns, which is a prerequisite for the establishment of specific functional contacts. The fruitfly Drosophila is a suitable model to approach the mechanisms controlling the generation of cell diversity and pattern in the developing CNS, as it allows linking of gene function to individually identifiable cells. This review addresses aspects of the formation and specification of neural stem cells (neuroblasts) in Drosophila in the light of recent studies on their segmental diversification. 相似文献
57.
Dietmar Winkler Matth?us Willeit Rainer Wolf Mara Stamenkovic Johannes Tauscher Edda Pjrek Anastasios Konstantinidis Shird Schindler Christian Barnas Siegfried Kasper 《European neuropsychopharmacology》2003,13(2):129-134
The value of a long-term treatment with clonazepam in the prophylaxis of affective disorder is discussed controversially in the scientific literature. Altogether there are only a few reports on the use of this compound as a mood stabilizer, most of them describing patients suffering from bipolar affective disorder. The aim of this investigation was to evaluate clonazepam as a phase prophylactic medication in affective disorder. We conducted a retrospective chart review in 34 out-patients of our lithium clinic (15 suffering from unipolar depression, 15 from bipolar disorder, four from schizoaffective disorder), who had been treated with clonazepam as a long-term medication. Clonazepam was either given as monotherapy, or as in the case of lithium non-responders, as adjunctive therapy. Patients with unipolar depression had significantly (P=0.026) less depressive episodes after initiation of treatment with clonazepam. Patients with bipolar disorder did not benefit from this therapy. Neither manic/hypomanic phases nor depressive episodes were reduced in this group of patients. Interestingly, clonazepam also reduced affective phases in our four schizoaffective patients on a trend level. Our results indicate that patients with unipolar depression may benefit from a maintenance treatment with clonazepam. Due to methodological limitations our results need to be replicated in controlled double-blind randomized clinical trials. 相似文献
58.
Knut E Kj?rstad Dag Ole Nordhaug Christian Korvald Stig Müller Tor Steensrud Truls Myrmel 《European journal of cardio-thoracic surgery》2007,31(4):677-684
OBJECTIVE: The time constant of mechanical restitution (T((MRC))), proposed to reflect changes in calcium release and uptake, has been shown to increase in left ventricular (LV) failure, and might have a potential as an index of contractile function. However, in vivo studies of the effect on T((MRC)) of changing loading conditions in the normal and failing heart have not been reported. Consequently, in this study, we tested the hypothesis that the increase in T((MRC)) in vivo is independent of preload and afterload. METHODS: Left ventricular pressure-volume loops were assessed at baseline in eight open chest pigs using the combined pressure-volume conductance catheter technique during right atrial pacing at 120b/min. Mechanical restitution curves (MRC) were constructed during four different loading conditions in all eight animals: uninfluenced load, reduced preload (balloon catheter in v. cava inferior), increased afterload (balloon catheter in descending aorta), and increased preload combined with reduced afterload (aortocaval shunting). Acute LV failure was then induced by microembolization through the left main coronary artery, and the experimental protocol was repeated. Contractile response was defined as the maximal first derivative of pressure (dP/dt(max)), and T((MRC)) was calculated using a least square approximation algorithm. RESULTS: Hemodynamic data 30min after microembolization showed decreased mean arterial pressure (98+/-14-67+/-10mmHg, (mean+/-SD) P<0.0001) and dP/dt(max) (1482+/-193-1001+/-125mmHg/s, P=0.001). Stroke volume decreased from 30+/-5 to 20+/-5ml (P<0.0001) compared to baseline, and preload recruitable stroke work decreased from 52+/-7 to 31+/-10mmHg (P=0.002). T((MRC)) increased in all eight animals after induction of LV failure at all loading conditions. There was no difference between the different loading conditions at baseline, nor at LV heart failure, but T((MRC)) increased significantly after the induction of heart failure (ANOVA, two ways). CONCLUSIONS: We have shown that the left ventricular T((MRC)) increases after developed heart failure. The increase in T((MRC)) was independent on loading conditions and thus have a potential for a contractility index. 相似文献
59.
60.
Stephan Haarmann Andi Setiawan Budihardja Thomas Mücke Christian Schwaegerl Klaus Dietrich Wolff 《Mund-, Kiefer- und Gesichtschirurgie》2007,11(6):363-367
Mechanical airway obstruction secondary to retropharyngeal bleeding is rare. In most cases such a complication is described
after head and neck trauma. Complicating factors include anticoagulant therapy, tumour, aneurysm, infection or major cervical
spine injury. A precise initial diagnosis is necessary to avoid a life-threatening situation. Lateral X-ray and computed tomography
is essential for safe management.
Treatment depends upon size of the haematoma as well as the clinical course of the patient. Smaller haematomas may be observed.
Lager haematomas and those that fail to reabsorb should undergo drainage.
相似文献