全文获取类型
收费全文 | 63993篇 |
免费 | 4089篇 |
国内免费 | 268篇 |
专业分类
耳鼻咽喉 | 830篇 |
儿科学 | 1345篇 |
妇产科学 | 854篇 |
基础医学 | 8422篇 |
口腔科学 | 1489篇 |
临床医学 | 6368篇 |
内科学 | 13805篇 |
皮肤病学 | 1334篇 |
神经病学 | 6852篇 |
特种医学 | 3400篇 |
外国民族医学 | 10篇 |
外科学 | 10640篇 |
综合类 | 403篇 |
一般理论 | 15篇 |
预防医学 | 3301篇 |
眼科学 | 920篇 |
药学 | 3965篇 |
中国医学 | 91篇 |
肿瘤学 | 4306篇 |
出版年
2023年 | 471篇 |
2022年 | 769篇 |
2021年 | 1634篇 |
2020年 | 968篇 |
2019年 | 1447篇 |
2018年 | 1676篇 |
2017年 | 1322篇 |
2016年 | 1607篇 |
2015年 | 1838篇 |
2014年 | 2295篇 |
2013年 | 2836篇 |
2012年 | 4532篇 |
2011年 | 4590篇 |
2010年 | 2678篇 |
2009年 | 2454篇 |
2008年 | 3970篇 |
2007年 | 4057篇 |
2006年 | 3807篇 |
2005年 | 3807篇 |
2004年 | 3392篇 |
2003年 | 3264篇 |
2002年 | 2983篇 |
2001年 | 1041篇 |
2000年 | 930篇 |
1999年 | 914篇 |
1998年 | 680篇 |
1997年 | 527篇 |
1996年 | 443篇 |
1995年 | 349篇 |
1994年 | 345篇 |
1993年 | 287篇 |
1992年 | 466篇 |
1991年 | 432篇 |
1990年 | 420篇 |
1989年 | 389篇 |
1988年 | 357篇 |
1987年 | 309篇 |
1986年 | 302篇 |
1985年 | 292篇 |
1984年 | 293篇 |
1983年 | 238篇 |
1982年 | 181篇 |
1981年 | 148篇 |
1979年 | 203篇 |
1978年 | 162篇 |
1977年 | 140篇 |
1976年 | 134篇 |
1975年 | 155篇 |
1974年 | 151篇 |
1973年 | 138篇 |
排序方式: 共有10000条查询结果,搜索用时 30 毫秒
101.
102.
103.
Bone marrow punctures and pain 总被引:1,自引:0,他引:1
We prospectively analysed pain in 263 patients induced by a frequent diagnostic procedure for oncologists, specifically the bone marrow puncture. Substantial pain (5 and more out of 10 on a numerical rating scale) was reported by 30.4% of patients, but physicians did not realize this procedure-related pain of patients in more than 50% of such punctures. The necessity for improved analgesia is emphasized by the fact, that at least 50% of patients experiencing substantial pain wished to receive concomitant medication in future punctures. Duration of the procedure was identified as sole independent predictive factor for patients’ pain intensity, while patients’ characteristics like gender, age and body-mass index (BMI) played only a minor role. As premedication with analgesics or anxiolytics may be associated with significant side-effects and an early identification of patients prone to experience severe pain is therefore difficult, further studies are warranted to establish an adequate approach in terms of pain control and feasibility in an ambulatory setting. In the meantime, daily physicians’ practice should be changed, as a pain-focused patient interview and presented indicators can be used in order to increase physicians’ awareness to procedure-related pain and augment their application of analgesics. 相似文献
104.
Bettina Seiberlich Nicolas Hunzelmann Axel Roers Manfred Weber Eckhard Schulze-Lohoff 《Medizinische Klinik》2005,108(4):137-142
Namensgebend für das Jo-1-Syndrom sind Autoantikörper gegen das Jo-1-Antigen, die bei diesem Krankheitsbild im Serum der betroffenen Patienten nachgewiesen werden. Der Name Jo-1 leitet sich von dem ersten Patienten (John P.) ab, bei dem diese Antikörper gefunden wurden. Dieser Patient litt an einer Polymyositis und fibrosierenden Alveolitis. Das Jo-1-Antigen ist identisch mit der Histidyl-Transfer-RNA-Synthetase im Zytosol. Das Jo-1-Syndrom gehört zu einer Familie von Autoimmunerkrankungen, die als Anti-Synthetase- Syndrome bezeichnet werden. Diese Syndrome haben gemeinsam, dass jeweils Autoantikörper gegen unterschiedliche Aminosäure-Transfer-RNASynthetasen nachweisbar sind. Klinisch handelt es sich beim Jo-1-Syndrom um eine Sonderform der Poly- bzw. Dermatomyositis von bisher ungeklärter Ätiologie. Neben einer Muskelbeteiligung kommt es charakteristischerweise zu einer interstitiellen Lungenbeteiligung, die auch prognostisch das Krankheitsbild bestimmt. Zusätzlich können klinisch eine Polyarthritis und weitere Symptome bestehen, die dem klinischen Bild anderer Kollagenosen ähneln. Ebenso wie die Polymyositis und Dermatomyositis kann sich das Jo-1-Syndrom in sog. Myositis-Overlap-Syndromen präsentieren. Zu dieser Diagnose führt ein Symptomenkomplex, der die klare Zuordnung zu einer einzelnen Erkrankung nicht möglich macht. Häufig werden in solchen Fällen U1-RNP-Antikörper nachgewiesen. Therapeutisch spricht das Jo-1-Syndrom auf die Gabe von Kortikosteroiden und—falls notwendig—Azathioprin, Methotrexat und Cyclophosphamid an. Eine Kurzbeschreibung von zwei klinischen Fällen stellt das Krankheitsbild anschaulich dar. 相似文献
105.
Tobias von Lukowicz Michela Silacci Matthias T Wyss Eveline Trachsel Christine Lohmann Alfred Buck Thomas F Lüscher Dario Neri Christian M Matter 《Journal of nuclear medicine》2007,48(4):582-587
Targeting proteins that are overexpressed in atherosclerotic plaques may open novel diagnostic applications. The C domain of tenascin-C is absent from normal adult tissues but can be inserted during tumor progression or tissue repair into the molecule by alternative splicing. We tested the ability of the human antibody G11, specific to this antigen, to reveal murine atherosclerotic plaques ex vivo. The antibody directed against the extra domain B of fibronectin (L19) was used as a reference. METHODS: We intravenously injected (125)I-labeled G11 or L19 antibodies into apolipoprotein E-deficient (ApoE(-/-)) mice and harvested the aortae 4 or 24 h later. En face analyses of distal aortae and longitudinal sections of the aortic arch were performed to compare antibody uptake using autoradiography with plaque staining using oil red O. Plaque macrophages were detected by immunohistochemistry (anti-CD68 staining). Biodistribution of injected antibodies was investigated in aortae and blood at 4 and 24 h. RESULTS: En face analyses revealed a significant correlation between radiolabeled G11 and fat-stained areas, increasing from 4 to 24 h, with a correlation coefficient of 0.92 (P < 0.0001) and an average signal-to-noise ratio of 104:1 at 24 h. Plaque imaging using L19 showed similar results (r = 0.86; P < 0.0001; signal-to-noise ratio, 72:1 at 24 h). Uptake of radiolabeled antibodies in histologic sections colocalized with fat staining and activated macrophages in aortic plaques. Biodistribution analyses confirmed specific accumulation in aortic plaques as well as rapid blood pool clearance of the antibodies 24 h after injection. Immunofluorescence analyses revealed increased expression of tenascin and fibronectin isoforms in macrophage-rich plaques. CONCLUSION: The antibody G11, specific to the C domain of tenascin-C, visualizes murine atherosclerotic plaques ex vivo. In conjunction with the increased expression of the C domain of tenascin-C in macrophage-rich plaques, the colocalization of G11 uptake with activated macrophages, and the favorable target-to-blood ratio at 24 h, this antibody may be useful for molecular imaging of advanced atherosclerotic plaques in the intact organism. 相似文献
106.
Takahiro Higuchi Stephan G Nekolla Antanas Jankaukas Axel W Weber Marc C Huisman Sybille Reder Sibylle I Ziegler Markus Schwaiger Frank M Bengel 《Journal of nuclear medicine》2007,48(2):288-294
The combination of small-animal PET and MRI data provides quantitative in vivo insights into cardiac pathophysiology, integrating information on biology and morphology. We sought to determine the feasibility of PET and MRI for the quantification of ischemic injury in the rat model. METHODS: Fourteen healthy male Wistar rats were studied with 18F-FDG PET and cine MRI. Myocardial viability was determined in a transmural myocardial infarction model in 12 additional rats, using 18F-FDG PET and delayed-enhancement MRI with gadolinium-diethylenetriaminepentaacetic acid. All PET was acquired with a dedicated small-animal PET system. MRI was performed on a 1.5-T clinical tomograph with a dedicated small-animal electrocardiographic triggering device and a small surface coil. RESULTS: In normal rats, 18F-FDG uptake was homogeneous throughout the left ventricle. The lowest mean uptake of the 18F-FDG was found in the apical regions (79% +/- 6.0% of maximum) and the highest uptake was in the anterior wall (93% +/- 4.3 % of maximum). Myocardial infarct size as determined by histology correlated well with defects of glucose metabolism obtained with 18F-FDG PET (r = 0.89) and also with delayed-enhancement MRI (r = 0.91). Left ventricular ejection fraction in normal rats measured by cine MRI was 57% +/- 5.4% and decreased to 38% +/- 12.9% (P < 0.001) in the myocardial infarction model. CONCLUSION: Integrating information from small-animal PET and clinical MRI instrumentation allows for the quantitative assessment of cardiac function and infarct size in the rat model. The MRI measurements of scar can be complemented by metabolic imaging, addressing the extent and severity of ischemic injury and providing endpoints for therapeutic interventions. 相似文献
107.
Scott L Kominsky Michele Doucet Kelly Brady Kristy L Weber 《Journal of bone and mineral research》2007,22(1):37-44
Bone metastases develop in approximately 30% of patients with RCC, and the mechanisms responsible for this phenomenon are unknown. We found that TGF-beta1 stimulation of RCC bone metastasis cells promotes tumor growth and bone destruction possibly by stimulating paracrine interactions between tumor cells and the bone. INTRODUCTION: Bone metastasis is a frequent complication and causes marked morbidity in patients with renal cell carcinoma (RCC). Surprisingly, the specific mechanisms of RCC interaction with bone have been scarcely studied despite the inability to prevent or effectively treat bone metastasis. Bone is a reservoir for various growth factors including the pleiotropic cytokine TGF-beta1. TGF-beta1 has been shown to have tumor-supportive effects on advanced cancers and evidence suggests its involvement in promoting the development of breast cancer bone metastasis. Here, we studied the potential role of TGF-beta1 in the growth of RCC bone metastasis (RBM). MATERIALS AND METHODS: To inhibit TGF-beta1 signaling, RBM cells stably expressing a dominant-negative (DN) TGF-betaRII cDNA were generated. The in vivo effect of TGF-beta1 on RBM tumor growth and osteolysis was determined by histological and radiographic analysis, respectively, of athymic nude mice after intratibial injection of parental, empty vector, or DN RBM cells. The in vitro effect of TGF-beta1 on RBM cell growth was determined after TGF-beta1 treatment by MTT assay. RESULTS: TGF-beta1 and the TGF-beta receptors I and II (TGF-betaRI/II) were consistently expressed in both RBM tissues and cell lines. Inhibition of TGF-beta1 signaling in RBM cells significantly reduced tumor establishment and osteolysis observed in vivo after injection into the murine tibia, although no effect on tumor establishment was observed after injection of RBM cells subcutaneously or into the renal subcapsule. Treatment of five RBM cell lines with TGF-beta1 in vitro either had no effect (2/5) or resulted in a significant inhibition (3/5) of cell growth, suggesting that TGF-beta1 may promote RBM tumor growth indirectly in vivo. CONCLUSIONS: TGF-beta1 stimulation of RBM cells plays a role in promoting tumor growth and subsequent osteolysis in vivo, likely through the initiation of tumor-promoting paracrine interactions between tumor cells and the bone microenvironment. These data suggest that inhibition of TGF-beta1 signaling may be useful in the treatment of RBM. 相似文献
108.
Paul Christian Schulze 《European heart journal》2007,28(9):1052-1053
Chronic heart failure is defined as the inability of the heartto meet the circulatory demands of the organism. While cardiacinjury, e.g. of ischaemic, toxic, metabolic, or genetic cause,is the initial abnormality, secondary changes occur over thecourse of the disease affecting most organ systems. This leadsto a variety of pathologic changes including endothelial, pulmonary,hepatic, renal, endocrine and skeletal muscle abnormalities,and the state of multi-organ impairment in chronic heart failureis now considered the syndrome of chronic heart failure.1 A neuroendocrine activation has been described early in 相似文献
109.
110.
The frozen elephant trunk technique for the treatment of extensive thoracic aortic aneurysms: operative results and follow-up. 总被引:1,自引:0,他引:1
Matthias Karck Ajay Chavan Nawid Khaladj Holger Friedrich Christian Hagl Axel Haverich 《European journal of cardio-thoracic surgery》2005,28(2):286-90; discussion 290
OBJECTIVE: The 'frozen' elephant trunk technique allows for single-stage repair of combined aortic arch and descending aortic aneurysms using a 'hybridprosthesis' with a stented and a non-stented end. This report summarizes the operative- and follow-up data (mean follow-up 14 months) with this new treatment. METHODS: Between 09/01 and 4/04, 22 patients (62+/-9 years; 9 female) with different aortic pathologies (15 aortic dissections, 7 aneurysms) were operated on after approval from the local institutional review board. The stented end of the hybridprosthesis was deployed in the descending aorta through the opened aortic arch during hypothermic circulatory arrest and selective antegrade cerebral perfusion. RESULTS: All patients survived the procedure but one patient died of acute hemorrhage due to rupture of the false lumen in the descending aorta on the second postoperative day. Two patients required reexploration of the chest for bleeding complications. In 2 of 4 patients who developed neurological dysfunction, symptoms resolved completely. In one of them, the descending aorta was perforated intraoperatively due to misplacement of the stented end of the hybridprosthesis. In all follow-up CT-scans thrombus formation in the descending aortic aneurysm excluded by the stented end of the hybridprosthesis has been observed. CONCLUSIONS: This procedure is performed through median sternotomy and combines the concepts of the elephant trunk operation and endovascular stenting of descending aortic aneurysms. Favourable intraoperative and postoperative results during follow-up with regard to thrombus formation around the stented descending aortic segment encourage us to evaluate all patients with thoracic aneurysms extending to proximal and distal of the left subclavian artery for this treatment. 相似文献