全文获取类型
收费全文 | 68137篇 |
免费 | 5463篇 |
国内免费 | 290篇 |
专业分类
耳鼻咽喉 | 681篇 |
儿科学 | 2104篇 |
妇产科学 | 1365篇 |
基础医学 | 9011篇 |
口腔科学 | 1284篇 |
临床医学 | 6851篇 |
内科学 | 14526篇 |
皮肤病学 | 1316篇 |
神经病学 | 6238篇 |
特种医学 | 2372篇 |
外国民族医学 | 11篇 |
外科学 | 9752篇 |
综合类 | 1227篇 |
一般理论 | 44篇 |
预防医学 | 5083篇 |
眼科学 | 2019篇 |
药学 | 4936篇 |
1篇 | |
中国医学 | 223篇 |
肿瘤学 | 4846篇 |
出版年
2023年 | 475篇 |
2022年 | 709篇 |
2021年 | 1691篇 |
2020年 | 1134篇 |
2019年 | 1583篇 |
2018年 | 1849篇 |
2017年 | 1413篇 |
2016年 | 1604篇 |
2015年 | 1752篇 |
2014年 | 2397篇 |
2013年 | 2895篇 |
2012年 | 4639篇 |
2011年 | 4815篇 |
2010年 | 2745篇 |
2009年 | 2316篇 |
2008年 | 3890篇 |
2007年 | 3995篇 |
2006年 | 3766篇 |
2005年 | 3492篇 |
2004年 | 3380篇 |
2003年 | 2919篇 |
2002年 | 2665篇 |
2001年 | 1735篇 |
2000年 | 1631篇 |
1999年 | 1428篇 |
1998年 | 642篇 |
1997年 | 490篇 |
1996年 | 465篇 |
1995年 | 437篇 |
1994年 | 377篇 |
1993年 | 315篇 |
1992年 | 831篇 |
1991年 | 774篇 |
1990年 | 742篇 |
1989年 | 643篇 |
1988年 | 606篇 |
1987年 | 609篇 |
1986年 | 612篇 |
1985年 | 594篇 |
1984年 | 444篇 |
1983年 | 378篇 |
1982年 | 264篇 |
1981年 | 224篇 |
1980年 | 228篇 |
1979年 | 397篇 |
1978年 | 253篇 |
1977年 | 241篇 |
1976年 | 190篇 |
1974年 | 213篇 |
1973年 | 209篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
71.
M Wong K Yasufuku T Nakajima F J F Herth Y Sekine K Shibuya T Iizasa K Hiroshima W K Lam T Fujisawa 《The European respiratory journal》2007,29(6):1182-1186
A diagnosis of sarcoidosis should be substantiated by pathological means in order to thoroughly exclude other diseases. The role of real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the diagnosis of sarcoidosis has not been reported. The purpose of the present study is to evaluate the diagnostic yield of EBUS-TBNA in demonstrating the pathological features of sarcoidosis. In total, 65 patients with suspected sarcoidosis, with enlarged hilar or mediastinal lymph nodes on computed tomography, were included in the study. Patients with a suspected or known malignancy or previously established diagnosis of sarcoidosis were excluded. Convex probe endobronchial ultrasonography integrated with a separate working channel was used for EBUS-TBNA. Surgical methods were performed in those in whom no granulomas were detected by EBUS-TBNA. Patients were followed up clinically. EBUS-TBNA was performed on a total of 77 lymph node stations in 65 patients. A final diagnosis of sarcoidosis was made for 61 (93.8%) of the patients. The remaining four patients were diagnosed as having Wegener's granulomatosis (n=1) or indefinite (n=3). In patients with a final diagnosis of sarcoidosis, EBUS-TBNA demonstrated noncaseating epithelioid cell granulomas in 56 (91.8%) of the patients. No complications were reported. Endobronchial ultrasound-guided transbronchial needle aspiration proved to be a safe procedure with a high yield for the diagnoses of sarcoidosis. 相似文献
72.
We thank Coceani and L'Abbate for their comments on our paper.We concur that pathophysiology cannot be inferred fromcoronary lumenography alone, and this was one of thekey motivations in conducting the present study. 相似文献
73.
Sanjay Sisodiya J Helen Cross Ingmar Blümcke David Chadwick John Craig Peter B Crino Paul Debenham Norman Delanty Frances Elmslie Mark Gardiner Jeffrey Golden David Goldstein David A Greenberg Renzo Guerrini Michael Hanna John Harris Paul Harrison Michael R Johnson George Kirov Dimitri M Kullman Andrew Makoff Carla Marini Rima Nabbout Lina Nashef Jeffrey L Noebels Ruth Ottman Munir Pirmohamed Asla Pitk?nen Ingrid Scheffer Simon Shorvon Graeme Sills Nicholas Wood Sameer Zuberi 《Epileptic Disord》2007,9(2):194-236
The Sixth Epilepsy Research Foundation workshop, held in Oxford in March 2006, brought together basic scientists, geneticists, epidemiologists, statisticians, pharmacologists and clinicians to consider progress, issues and strategies for harnessing genetics to improve the understanding and treatment of the epilepsies. General principles were considered, including the fundamental importance of clear study design, adequate patient numbers, defi ned phenotypes, robust statistical data handling, and follow-up of genetic discoveries. Topics where some progress had been made were considered including chromosomal abnormalities, neurodevelopment, hippocampal sclerosis, juvenile myoclonic epilepsy, focal cortical dysplasia and pharmacogenetics. The ethical aspects of epilepsy genetics were reviewed. Principles and limitations of collaboration were discussed. Presentations and their matched discussions are produced here. There was optimism that further genetic research in epilepsy was not only feasible, but might lead to improvements in the lives of people with epilepsy. 相似文献
74.
The molecular events responsible for controlling cell growth and development, as well as their coordinate interaction is only beginning to be revealed. At the basis of these controlling events are hormones, growth factors and mitogens which, through transmembrane signalling trigger an array of cellular responses, initiated by receptor-associated tyrosine kinases, which in turn either directly or indirectly mediate their effects through serine/threonine protein kinases. Utilizing the obligatory response of activation of protein synthesis in cell growth and development, we describe efforts to work backwards along the regulatory pathway to the receptor, identifying those molecular components involved in modulating the rate of translation. We begin by describing the components and steps of protein synthesis and then discuss in detail the regulatory pathways involved in the mitogenic response of eukaryotic cells and during meiotic maturation of oocytes. Finally we discuss possible future work which will further our understanding of these systems. 相似文献
75.
76.
Simon R Cherry 《Journal of nuclear medicine》2006,47(11):1735-1745
There have been major advances in PET technology that cumulatively have helped improve image quality, increased the range of applications for PET, and contributed to the more widespread use of PET. Examples of these technologic advances include whole-body imaging, 3-dimensional imaging, new scintillator materials, iterative reconstruction algorithms, combined PET/CT, and preclinical PET. New advances on the immediate horizon include the reintroduction of time-of-flight PET, which takes advantage of the favorable timing properties of newer scintillators; the integration of PET and MRI scanners into a dual-modality imaging system; and the possibility of further significant improvements in spatial resolution in preclinical PET systems. Sensitivity remains a limiting factor in many PET studies. Although, conceptually, huge gains in sensitivity are still possible, realizing these gains is thwarted largely by economic rather than scientific concerns. Predicting the future is fraught with difficulty; nonetheless, it is apparent that ample opportunities remain for new development and innovation in PET technology that will be driven by the demands of molecular medicine, notably sensitive and specific molecular diagnostic tools and the ability to quantitatively monitor therapeutic entities that include small molecules, peptides, antibodies, nanoparticles, DNA/RNA, and cells. 相似文献
77.
78.
Michael Schenker Mikael Wiberg Simon P Kay Roland S Johansson 《Journal of plastic, reconstructive & aesthetic surgery》2007,60(1):13-23
Although toe-to-hand transfer has a defined role in the management of congenital hand deformities, it remains unclear how well children integrate the transferred digits into physiological grasping. We analysed fingertip forces in the precision grip of 13 patients when lifting a test object more than three years after free toe transfer for absent or hypoplastic digits. Clinically, most patients showed normal sensibility of transferred digits, but active motion and pinch strength were limited as compared to the normal hand. For the control of fingertip forces, two key features of the normal two-digit opposition grip were seen in all operated hands: adaptation of grip force to object weight and parallel coordination of lift and grip forces. These physiological grasping strategies developed independently of the patients' age at the time of operation, which ranged from one to 13 years. In four patients, we observed increased tangential load forces with the operated hand due to misalignments in the application of fingertips on the grasp surfaces. Such forces lead to increased grip force requirements on both fingers that may overload transferred digits with limited motor function. The need for optimal alignment of the grip axis during toe-transfer surgery is emphasised. 相似文献
79.
Ohne ZusammenfassungMit einer Tafel. 相似文献
80.
J C Ho M Chan-Yeung S P Ho J C Mak M S Ip G C Ooi M P Wong K W Tsang W K Lam 《The European respiratory journal》2007,29(2):273-278
The present study aimed to determine the alterations of antioxidant activities in erythrocytes from patients with nonsmall cell lung carcinoma (NSCLC). A comparative study of the systemic antioxidant activities in red blood cell lysate from subjects with NSCLC and healthy control subjects was conducted. The antioxidants catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were measured using chemical kinetic reactions under spectrophotometry. In total, 189 cases of mostly advanced-stage IIIB or stage IV NSCLC and 202 healthy controls were studied. In subjects with lung cancer, there was similar catalase activity, lower SOD activity (median (interquartile range) 13.4 (9.0-27.2) versus 48.7 (27.0-64.3) U x (ghaemoglobulin(Hb)(-1)), and higher GPx activity (175.2 (126.6-288.3) versus 49.2 (39.5-59.2) mU x (gHb)(-1)) compared with controls. The antioxidant activities in lung cancer subjects were not associated with age, sex, smoking status, or tumour cell types. However, more advanced disease (stage IV compared with stage IIIB) was associated with lower SOD activity. Using multivariable analysis, the presence of lung cancer independently predicted SOD and GPx activities. In conclusion, nonsmall cell lung carcinoma in Chinese subjects is associated with alterations in systemic antioxidant activities, which may play an important role in carcinogenesis. 相似文献