全文获取类型
收费全文 | 34716篇 |
免费 | 2166篇 |
国内免费 | 205篇 |
专业分类
耳鼻咽喉 | 328篇 |
儿科学 | 640篇 |
妇产科学 | 475篇 |
基础医学 | 4801篇 |
口腔科学 | 902篇 |
临床医学 | 3583篇 |
内科学 | 7396篇 |
皮肤病学 | 729篇 |
神经病学 | 3862篇 |
特种医学 | 2005篇 |
外科学 | 5531篇 |
综合类 | 198篇 |
一般理论 | 7篇 |
预防医学 | 1468篇 |
眼科学 | 695篇 |
药学 | 2015篇 |
中国医学 | 68篇 |
肿瘤学 | 2384篇 |
出版年
2024年 | 28篇 |
2023年 | 272篇 |
2022年 | 521篇 |
2021年 | 902篇 |
2020年 | 639篇 |
2019年 | 823篇 |
2018年 | 950篇 |
2017年 | 818篇 |
2016年 | 952篇 |
2015年 | 1174篇 |
2014年 | 1387篇 |
2013年 | 1680篇 |
2012年 | 2753篇 |
2011年 | 2873篇 |
2010年 | 1714篇 |
2009年 | 1540篇 |
2008年 | 2438篇 |
2007年 | 2445篇 |
2006年 | 2292篇 |
2005年 | 2228篇 |
2004年 | 2025篇 |
2003年 | 1845篇 |
2002年 | 1681篇 |
2001年 | 332篇 |
2000年 | 251篇 |
1999年 | 299篇 |
1998年 | 322篇 |
1997年 | 241篇 |
1996年 | 186篇 |
1995年 | 164篇 |
1994年 | 133篇 |
1993年 | 128篇 |
1992年 | 87篇 |
1991年 | 75篇 |
1990年 | 75篇 |
1989年 | 61篇 |
1988年 | 60篇 |
1987年 | 47篇 |
1986年 | 53篇 |
1985年 | 41篇 |
1984年 | 51篇 |
1983年 | 42篇 |
1982年 | 36篇 |
1981年 | 29篇 |
1980年 | 25篇 |
1979年 | 17篇 |
1978年 | 21篇 |
1977年 | 18篇 |
1974年 | 20篇 |
1965年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
Kathrin Scherer Wolfgang Studer Verena Figueiredo Andreas J Bircher 《Annals of allergy, asthma & immunology》2006,96(3):497-500
BACKGROUND: Blue dyes used for lymphatic mapping in sentinel lymph node biopsy cause intraoperative anaphylactic reactions in up to 2.7% of patients. With increasing implementation of this technique, the incidence of anaphylaxis to these dyes can be expected to increase. In the literature, the chemically often unrelated and inconsistently designated dyes have been confused, adding to other inconsistencies in the nomenclature. OBJECTIVE: To demonstrate the nomenclature, chemical and physiologic differences, and allergenicity of the various blue dyes used in a medical context. METHODS: We describe a patient with an intraoperative grade IV anaphylactic reaction to isosulfan blue. Immediate-type hypersensitivity was proved by positive skin test reactions and CD63 expression to isosulfan blue and cross-reactivity to patent blue V. RESULTS: A review of the literature clarified the exact nomenclature of the blue dyes and the possible pitfalls of confusing nomenclature in the context of structurally closely related dyes with different allergenic properties. For the detection of type I hypersensitivity, intracutaneous tests are valuable tools. An IgE-mediated mechanism has been shown recently. In most cases, sensitization exists without known previous exposure in a medical context. This may be due to the widespread use of such dyes in objects of everyday life. Preoperative antiallergic medication use does not prevent anaphylactic reactions but apparently reduces their severity. CONCLUSION: For better comparison and precision, the Chemical Abstracts Service number of the respective dye should always be given. 相似文献
33.
Andreas Frei und René Raggenbas 《Sozial- und Pr?ventivmedizin》1989,34(6):279-280
34.
F K Meissner 《Arzneimittel-Forschung》1987,37(1):17-18
In animal experiments the effects of Echinacin, a sap made from Herba recens Echinaceae purpureae, on the rate of necrosis of skin flaps were studied in comparison with NaCl and pentoxifylline. The fluoresceine test was used as an indicator of peripheral circulation. The noncirculated area of the skin flap was significantly smaller in Herba Echinaceae treated animals than in control animals (p less than 0.01). On the day of the operation the size of the noncirculated flap area was only 56.0%, whereas it was 77.8% in the NaCl group and 67.4% in the pentoxifylline group. Until the 5th postoperative day the ratios changed to 47.4% (Herba Echinaceae), 76.6% (NaCl) and 50.4% (pentoxifylline). While more than two thirds of the skin flap area were to become necrotic in the NaCl group, less than half of the skin flap was so in the Herba Echinaceae group. Thus Herba Echinaceae significantly decreased the rate of necrosis of skin flaps in animal experiments. 相似文献
35.
Jens Garbade Andreas Schubert Ardawan Julian Rastan Dominik Lenz Thomas Walther Jan Fritz Gummert Stefan Dhein Friedrich-Wilhelm Mohr 《European journal of cardio-thoracic surgery》2005,28(5):685-691
OBJECTIVE: Recent studies have demonstrated that transplanted bone marrow-derived stem cells (BMCs) possess a broad differentiation potential and are able to form new cardiomyocytes. However, the identity of BMCs as true cardiomyocytes is still ambiguous. Therefore, we investigated the fate of transplanted fluorescence labeled BMCs and cardiomyocytes in co-culture. METHODS: For cell tracking we used two different fluorescent probes, Vybrant/DiO and Vybrant/DiI. BMCs were taken from human sternal marrow, purified using a Ficoll-gradient-centrifugation, treated with 5-azacytidine and stained with Vybrant/DiO. Furthermore, isolated spontaneous beating cardiomyocytes of neonatal rats (CM) were labeled with Vybrant/DiI. Thereafter, the BMCs were transplanted into CM-cultures and investigated on day 1, 4, 7, 14 and 28 using two-color fluorescence phenotyping by laser-scanning-cytometry (LSC). Two-color positive cells were harvested by patch-clamp technique and beta-MHC mRNA expression was analyzed by single-cell PCR. RESULTS: Two different morphological phenotypes were observed by LSC. First, isolated DiO labeled BMCs without contact or with direct cell contact to DiI labeled CMs. Second, some BMCs and CMs were double positive for DiO/DiI spontaneously forming hybrids. This population increased by 18% from day 1 to 4 and decreased only slightly until day 28. Additionally, few two-color positive cell formations expressed both human and rat specific beta-MHC mRNA as well as only human beta-MHC mRNA indicating that cell-fusion and transdifferentiation has occurred. CONCLUSION: These observations provide in vitro evidence for spontaneous cell fusion and transdifferentiation of BMCs in co-culture, raising the possibility that the observed phenomenons may contribute to development or maintenance of these cell types. 相似文献
36.
Meta-analysis of randomized controlled comparisons of psychopharmacological and psychological treatments for anxiety disorders. 总被引:2,自引:0,他引:2
Borwin Bandelow Ulrich Seidler-Brandler Andreas Becker Dirk Wedekind Eckart Rüther 《The world journal of biological psychiatry》2007,8(3):175-187
BACKGROUND: A number of meta-analyses have led to contradictory results regarding the efficacy of the psychological and pharmacological treatment of anxiety disorders. The main reasons for these inconsistent results seem to be the inclusion of heterogeneous studies and influences of selection biases. We performed a meta-analysis, which only included studies using a direct comparison of pharmacological, psychological, or combined treatments. METHOD: Sixteen studies on panic disorder, six studies on social anxiety disorder, and two studies on generalized anxiety disorder have been analyzed. Effect sizes for differences between the different treatment modalities were calculated. Also, the effect sizes of the pre-post differences were calculated. RESULTS: Pharmacological treatment, cognitive-behavioural treatment, and the combination of both treatment modalities all led to substantial improvement between pre- and post-treatment. Combined pharmacological and psychological treatment was superior to the monotherapies for panic disorder. For social anxiety disorder, there is only preliminary support for combined treatment. Due to lack of sufficient data, no final conclusions can be drawn for generalized anxiety disorder. CONCLUSIONS: While drug treatment and CBT showed equal efficacy, only in panic disorder the combination of pharmacological and psychological treatment was superior to either treatment alone. For the other anxiety disorders, the evidence for greater efficacy of combination treatment is still not sufficient due to lack of studies. 相似文献
37.
Christos K. Kyriakopoulos Andreas F. Mavrogenis Ioannis S. Benetos Demetrios Koulalis Argyris Mitsou Panayiotis J. Papagelopoulos 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2006,16(1):75-79
A 34-year-old male soccer player with chronic right ankle dysfunction and a history of repeated ankle joint injuries is presented. Imaging studies revealed synovial chondromatosis of the ankle joint. Arthroscopic partial synovectomy was performed and more than 20 loose bodies were excised. Four months postoperatively the patient was asymptomatic and has returned to his previous level of sport activities. At the latest follow-up, 2 years after the initial diagnosis there is no local recurrence of the disease. Arthroscopy is a minimal invasive surgical technique, with satisfactory results in the treatment of synovial chondromatosis of the ankle joint. 相似文献
38.
39.
Woltmann Alexander Thannheimer Andreas Hauck Stefan Bhren Volker 《Trauma und Berufskrankheit》2003,5(2):s293-s295
Abdominal infection has the fifth highest incidence of all posttraumatic infections but has the second highest mortality rate with 25%,pneumonia,with 29%, being the only posttraumatic infection that is more frequently lethal.Posttraumatic abdominal sepsis, on the other hand, has a mortality rate of almost 50%.This rate cannot be reduced except by prompt identification of the correct diagnosis of the underlying injury or complication.This means that delayed laparotomy is strikingly detrimental in these patients, with 46% mortality as opposed to 11% in patients who undergo laparotomy promptly. In parallel with this, the mortality of fresh-onset and localized peritonitis is 14%,whereas that of diffuse purulent peritonitis is up to a devastating 42%. 相似文献
40.
Hochstein Paul Heppert Volkmar Grtzner Paul Alfred Matschke Stefan Wentzensen Andreas 《Trauma und Berufskrankheit》2003,5(1):s56-s61
Malunion and nonunion after fracture present many difficulties in trauma surgery. Selection of the best therapy and operative techique requires careful analysis of the complications. Hyperthrophic nonunion of the femur shaft is mostly best treated with locking reamed nails. Significant differences in torsions after nailing can be corrected by repositioning of the distal interlocking screws if recognized sufficiently early. After fracture healing an open rotation osteotomy is necessary; stabilization can be achieved by means of medullary nails or a condylar plate. How a malalignment of the bone axis is corrected depends on the position of a malunion, the functional deficit caused, and the biomechanical demands on the joint. Condylar plates can often solve the problems in this region. There are also guidelines for ¶the treatment of atrophic and infected nonunions (recommended procedures are ¶aggressive debridement, autologous cancellous bone graft, and biological osteosynthesis), but the treatment of individual cases requires a exhaustive knowledge of and experience in this special field. It is quite common for even well-established procedures to fail. When the bone is biologically reduced and this is the reason for malunion newly developed techniques of internal fixation can be applied. The less invasive stabilization system (LISS), combined with autologous cancellous bone grafting if necessary, can result in healing even in a worst-case scenario. 相似文献