全文获取类型
收费全文 | 14520篇 |
免费 | 789篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 91篇 |
儿科学 | 261篇 |
妇产科学 | 184篇 |
基础医学 | 2270篇 |
口腔科学 | 104篇 |
临床医学 | 1517篇 |
内科学 | 3115篇 |
皮肤病学 | 384篇 |
神经病学 | 1368篇 |
特种医学 | 550篇 |
外科学 | 2329篇 |
综合类 | 63篇 |
一般理论 | 3篇 |
预防医学 | 870篇 |
眼科学 | 245篇 |
药学 | 985篇 |
中国医学 | 40篇 |
肿瘤学 | 1025篇 |
出版年
2023年 | 65篇 |
2022年 | 92篇 |
2021年 | 281篇 |
2020年 | 162篇 |
2019年 | 242篇 |
2018年 | 347篇 |
2017年 | 214篇 |
2016年 | 250篇 |
2015年 | 291篇 |
2014年 | 400篇 |
2013年 | 543篇 |
2012年 | 977篇 |
2011年 | 1116篇 |
2010年 | 634篇 |
2009年 | 581篇 |
2008年 | 957篇 |
2007年 | 1062篇 |
2006年 | 970篇 |
2005年 | 1005篇 |
2004年 | 918篇 |
2003年 | 925篇 |
2002年 | 898篇 |
2001年 | 193篇 |
2000年 | 162篇 |
1999年 | 190篇 |
1998年 | 223篇 |
1997年 | 179篇 |
1996年 | 169篇 |
1995年 | 123篇 |
1994年 | 118篇 |
1993年 | 116篇 |
1992年 | 131篇 |
1991年 | 87篇 |
1990年 | 65篇 |
1989年 | 79篇 |
1988年 | 61篇 |
1987年 | 68篇 |
1986年 | 61篇 |
1985年 | 36篇 |
1984年 | 53篇 |
1983年 | 46篇 |
1982年 | 48篇 |
1981年 | 34篇 |
1980年 | 37篇 |
1979年 | 27篇 |
1978年 | 28篇 |
1977年 | 21篇 |
1976年 | 14篇 |
1975年 | 12篇 |
1974年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Full-thickness tears of the rotator cuff of the shoulder: diagnosis with MR imaging. 总被引:4,自引:0,他引:4
T E Farley C H Neumann L S Steinbach A J Jahnke S S Petersen 《AJR. American journal of roentgenology》1992,158(2):347-351
The purpose of this study was to describe MR findings in full-thickness tears of the rotator cuff. Of 102 shoulders examined by MR imaging, 31 were found to have a full-thickness tendon tear at arthroscopy/bursoscopy (five shoulders) or open surgery (26 shoulders). All shoulders were imaged in oblique coronal and axial planes. MR images of the 102 shoulders were evaluated for (1) the presence of fluid in the subacromial and subdeltoid bursae; (2) abnormal signal of the supraspinatus, subscapularis, infraspinatus, and teres minor tendons; (3) interruption of tendon continuity and thinning of the tendon; and (4) proximal retraction of the junction of the muscle and tendon. The presence or absence of each finding was determined by consensus of two radiologists, who interpreted the images without knowledge of the surgical findings. Results in those 31 shoulders with proved full-thickness tears were: fluid in the subacromial bursae (29 shoulders), interruption of tendinous continuity (22 shoulders), focally increased signal of the tendon equivalent to that of water (27 shoulders), and musculotendinous retraction (24 shoulders). The finding of subacromial fluid was a sensitive indicator (93%) of a full-thickness tear, and interruption of tendinous continuity was a specific finding (96%) in diagnosing a full-thickness tear. Our experience shows interruption of tendon continuity is the most specific MR finding of full-thickness rotator cuff tears, while subacromial fluid is the most common finding. 相似文献
22.
Photocarcinogenesis and inhibition of intercellular adhesion molecule 1 expression in cells of DNA-repair-defective individuals 下载免费PDF全文
23.
Minerva Giménez y Ribotta Christelle Roudet Françoise Sandillon Alain Privat 《Brain research》1996,707(2):245
The synaptic connections established by grafted noradrenergic (NA) neurons into the lesioned adult rat spinal cord were analysed using immunocytochemistry at the electron microscopic level. An embryonic cell suspension of the locus coeruleus region from E-13 rat embryos was transplanted into the spinal cord following either: (1) spinal cord transection or (2), partial selective denervation by 6-hydroxy dopamine (6-OH DA). One month after grafting, the NA-neurons established, in the two models, an innervation pattern similar to that found in the intact spinal cord. In both models, the transplanted NA-immunoreactive neurons formed extensive synaptic contacts with dendrites, spines and perikarya. The proportion of axodendritic and axospinous contacts was inverse in the two models. The first model thus reproduced more closely the normal synaptic pattern prefering dendritic targets, which could correspond to a better integration of the graft. In the second model, a partially NA-denervated spinal cord, there existed a competition between residual intrinsic and grafted neuron-derived fibres, which presumably affects synaptogenesis. In conclusion, the present study illustrate the complexity of cell interations conducting to the formation of a specific circuitry. Recognition phenomenon are likely modulated by space constraints, which ultimately shape-up the geometry of synaptic contacts. 相似文献
24.
Philippe Brun Heykel Kchouk Brigitte Mouchet Véronique Baudouin Alain Raynaud Chantal Loirat Annabelle Azancot-Benisty 《Pediatric nephrology (Berlin, Germany)》1997,11(1):27-30
To evaluate the reliability of Doppler ultrasonography (US) in identifying children with renal artery stenosis (RAS) among
those with hypertension, we compared Doppler US results in 22 hypertensive children (mean age 8.9±4.3 years), with (13 cases)
and without RAS at angiography, and in 33 normotensive children (mean age 8.8±4.7 years). We observed 2 false-negatives and
2 false-positives with Doppler US. Of the 2 false-negative diagnoses, 1 had RAS on an accessory renal artery located behind
a normal upper polar artery and the other was observed in a patient with bilateral multiple stenosis of the very distal segments
of renal arteries. The 2 false-positive diagnoses were due to sinuous left renal artery and to technical reasons, respectively.
In another patient, Doppler US showed a tight RAS, while arteriography was normal. RAS was subsequently confirmed by a second
arteriography. Peak systolic velocity values of Doppler US were significantly higher in patients with proven angiographic
RAS (3.44±0.66 m/s) than in hypertensive patients with normal renal arteries at angiography (0.99±0.35 m/s, P <0.0001) and normotensive healthy children (1.04±0.23 m/s, P <0.0001). With the use of multiple views, and the experience acquired with practice, false-negatives or false-positives due
to the geometry of the renal artery can be avoided. Nevertheless, very distal stenosis can be missed by Doppler US.
Received October 30, 1995; received in revised form April 16, 1996; accepted May 14, 1996 相似文献
25.
26.
Georgios Amoiridis Ludwig Gutmann Dennis E. Wilkins Raja Sawaya Alain Lagueny Roger Marthan Philippe Schuermans Philippe Le Collen Xavier Ferrer Jean Julien Reha Kuruoglu Shin J. Oh Brian Thompson A. Aggarwal L. Gutmann A. Gutierrez Okifumi Nakazato Russel Johnsen Philip Morling B. A. Kakulas 《Muscle & nerve》1994,17(2):245-253
27.
Alain Djacoba Tehindrazanarivelo Jean Marc Visy Marie-Germaine Bousser 《Cephalalgia : an international journal of headache》1992,12(5):318-320
We report two patients with ipsilateral attacks of cluster headache and chronic paroxysmal hemicrania. The first patient, a 33-year-old man, started having attacks of chronic cluster headache at the age of 27. At 33, they were replaced by typical attacks of ipsilateral chronic paroxysmal hemicrania which showed a dramatic improvement with indomethacin 150 mg daily. After two days of complete remission, cluster headache attacks reappeared and persisted until verapamil, 360 mg a day, was added to indomethacin. The second patient, a 45-year-old man, first developed attacks of episodic cluster headache at the age of 35. At 44, he experienced ipsilateral typical attacks of chronic paroxysmal hemicrania, and two months later attacks of cluster headache. Under verapamil 240 mg daily, attacks of cluster headache disappeared, but those of chronic paroxysmal hemicrania increased in frequency until indomethacin 150 mg daily was added. These observations suggest a close relationship but not a similarity between cluster headache and chronic paraoxysmal hemicrania, and show the practical therapeutic interest of maintaining this distinction. 相似文献
28.
29.
30.
Didier Mathieu Alain Rahmouni Norbert Vasile Nedal Jazaerli Christophe Duvoux Jeanne Tran Van Nhieu Elie Serge Zafrani 《Journal of magnetic resonance imaging : JMRI》1994,4(3):506-508
This case report illustrates atypical magnetic resonance (MR) imaging findings in a liver hemangioma mimicking a malignant lesion—lower signal intensity than cerebrospinal fluid on T2-weighted spin-echo images and lack of early enhancement on dynamic contrast material—enhanced gradient-echo images. Pathologic analysis demonstrated nearly total replacement of the vascular cavities by dense fibrous tissue. In this rare, sclerosed form, this lesion could not be defined as a hemangioma with MR imaging. 相似文献