全文获取类型
收费全文 | 10071篇 |
免费 | 752篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 141篇 |
儿科学 | 434篇 |
妇产科学 | 179篇 |
基础医学 | 1080篇 |
口腔科学 | 191篇 |
临床医学 | 824篇 |
内科学 | 2407篇 |
皮肤病学 | 200篇 |
神经病学 | 596篇 |
特种医学 | 345篇 |
外国民族医学 | 1篇 |
外科学 | 1569篇 |
综合类 | 226篇 |
一般理论 | 7篇 |
预防医学 | 589篇 |
眼科学 | 362篇 |
药学 | 895篇 |
中国医学 | 75篇 |
肿瘤学 | 736篇 |
出版年
2023年 | 78篇 |
2022年 | 167篇 |
2021年 | 388篇 |
2020年 | 208篇 |
2019年 | 271篇 |
2018年 | 347篇 |
2017年 | 217篇 |
2016年 | 266篇 |
2015年 | 269篇 |
2014年 | 381篇 |
2013年 | 450篇 |
2012年 | 708篇 |
2011年 | 689篇 |
2010年 | 368篇 |
2009年 | 336篇 |
2008年 | 539篇 |
2007年 | 529篇 |
2006年 | 484篇 |
2005年 | 452篇 |
2004年 | 429篇 |
2003年 | 399篇 |
2002年 | 337篇 |
2001年 | 235篇 |
2000年 | 241篇 |
1999年 | 211篇 |
1998年 | 80篇 |
1997年 | 72篇 |
1996年 | 65篇 |
1995年 | 55篇 |
1994年 | 45篇 |
1993年 | 42篇 |
1992年 | 166篇 |
1991年 | 122篇 |
1990年 | 116篇 |
1989年 | 101篇 |
1988年 | 123篇 |
1987年 | 90篇 |
1986年 | 86篇 |
1985年 | 108篇 |
1984年 | 74篇 |
1983年 | 43篇 |
1982年 | 28篇 |
1981年 | 30篇 |
1979年 | 70篇 |
1978年 | 28篇 |
1974年 | 25篇 |
1973年 | 25篇 |
1972年 | 29篇 |
1971年 | 27篇 |
1969年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Discordant Electrocardiogram Left Ventricular Wall Thickness and Strain Findings in Influenza Myocarditis
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nael Hawwa M.D. Zoran B. Popovic M.D. Ph.D. Hussain A. Isma'eel M.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(12):1880-1884
A 42‐year‐old man presented with a viral prodrome and tested positive for influenza A. He rapidly deteriorated developing cardiogenic shock, rhabdomyolysis, and acute kidney injury. Patient improved 1 week later with supportive measures including vasopressors, inotropes, and an intraaortic balloon pump. We report this case as it highlights the discordance between echocardiographic ventricular wall thickening as a result of myocardial edema, and electrocardiographic findings at presentation, with a reversal in findings at time of resolution. Additionally, there was some suggestion of a regional pattern to the reduced longitudinal strain. 相似文献
3.
4.
5.
6.
7.
Waseem Raza Hafiza Anum Mohy-u-Din Sajid Shaeen Malik Iqra Manzoor Baby Nadeem 《Ultrasound in medicine & biology》2019,45(1):21-25
The objective of the study was to evaluate the reliability of sonoelastography in ductal carcinoma in patients in primary and secondary health care settings. Google Scholar, PubMed, Medline, Medscape, Wikipedia and NCBI were searched in January 2018 for all original research and review articles to identify relevant studies. Two reviewers selected the articles independently for based on the title and abstract. The selection criteria were sonoelastography accuracy for diagnosing ductal carcinoma as index text, B-mode sonography, and micropure imaging; surgery and histologic findings were used as reference text; and benign and malignant breast abnormalities and ductal carcinoma were used as target conditions. Two reviewers extracted the data on selected study characteristics, and the results were used to construct the tables and figures. Fifteen studies on ductal carcinoma were found. The overall sensitivity of sonoelastography in diagnosing ductal carcinoma was 85.7%, and the specificity, 79.8%. On the basis of the literature review, it was concluded that sonoelastography has high sensitivity and specificity in diagnosing ductal carcinoma. 相似文献
8.
G Steinitz M C Martín N Gazit-Yaari M L Quesada J de la Nuez R Casillas U Malik Z B Begin 《Applied radiation and isotopes》2006,64(4):520-524
Multi-day signals, generally with duration of 2-10 days, are a prominent temporal variation type of radon (Rn) in geogas in the unsaturated zone. Rare multi-day Rn signals have been found which are characterized by: (a) a declining limb lasting up to 10 days which conforms to the radioactive decay of Rn, (b) recurs at the same location and (c) is recorded in diverse situations-volcanic and seismogenic. It suggested that a Rn blob is injected at a lower level on a steady upward flow of geogas whereby the rise and final fall of the signal are attributed to the edges of the blob while the central Rn-decay segment records the passing of the decaying blob itself. Rn-decay signals are a small subset of multi-day Rn signals which are considered as highly irregular and unusable for the understanding of geophysical processes. In difference, it is concluded that multi-day Rn signals are probably proxies of subtle geodynamic processes at upper crustal levels and are therefore significant for studying such processes. 相似文献
9.
10.
Mozammil Hussain Raghu N. Natarajan Amir H. Fayyazi Brian R. Braaksma Gunnar B.J. Andersson Howard S. An 《The spine journal》2009,9(12):1016-1023
Background contextAnterior corpectomy and reconstruction with bone graft and a rigid screw-plate construct is an established procedure for treatment of cervical neural compression. Despite its reliability in relieving symptoms, there is a high rate of construct failure, especially in multilevel cases.PurposeThere has been no study evaluating the biomechanical effects of screw angulation on construct stability; this study investigates the C4–C7 construct stability and load-sharing properties among varying screw angulations in a rigid plate-screw construct.Study designA finite element model of a two-level cervical corpectomy with static anterior cervical plate.MethodsA three-dimensional finite element (FE) model of an intact C3–T1 segment was developed and validated. From this intact model, a fusion model (two-level [C5, C6] anterior corpectomy) was developed and validated. After corpectomy, allograft interbody fusion with a rigid anterior screw-plate construct was created from C4 to C7. Five additional FE models were developed from the fusion model corresponding to five different combinations of screw angulations within the vertebral bodies (C4, C7): (0°, 0°), (5°, 5°), (10°, 10°), (15°, 15°), and (15°, 0°). The fifth fusion model was termed as a hybrid fusion model.ResultsThe stability of a two-level corpectomy reconstruction is not dependent on the position of the screws. Despite the locked screw-plate interface, some degree of load sharing is transmitted to the graft. The load seen by the graft and the shear stress at the bone-screw junction is dependent on the angle of the screws with respect to the end plate. Higher stresses are seen at more divergent angles, particularly at the lower level of the construct.ConclusionThis study suggests that screw divergence from the end plates not only increases load transmission to the graft but also predisposes the screws to higher shear forces after corpectomy reconstruction. In particular, the inferior screw demonstrated larger stress than the upper-level screws. In the proposed hybrid fusion model, lower stresses on the bone graft, end plates, and bone-screw interface were recorded, inferring lower construct failure (end-plate fractures and screw pullout) potential at the inferior construct end. 相似文献