全文获取类型
收费全文 | 1607篇 |
免费 | 150篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 75篇 |
妇产科学 | 63篇 |
基础医学 | 286篇 |
口腔科学 | 23篇 |
临床医学 | 134篇 |
内科学 | 264篇 |
皮肤病学 | 26篇 |
神经病学 | 37篇 |
特种医学 | 178篇 |
外科学 | 147篇 |
综合类 | 123篇 |
一般理论 | 7篇 |
预防医学 | 139篇 |
眼科学 | 39篇 |
药学 | 85篇 |
中国医学 | 2篇 |
肿瘤学 | 122篇 |
出版年
2021年 | 19篇 |
2020年 | 15篇 |
2019年 | 18篇 |
2018年 | 24篇 |
2017年 | 20篇 |
2016年 | 25篇 |
2015年 | 39篇 |
2014年 | 45篇 |
2013年 | 47篇 |
2012年 | 66篇 |
2011年 | 57篇 |
2010年 | 62篇 |
2009年 | 49篇 |
2008年 | 59篇 |
2007年 | 59篇 |
2006年 | 60篇 |
2005年 | 49篇 |
2004年 | 43篇 |
2003年 | 44篇 |
2002年 | 46篇 |
2001年 | 41篇 |
2000年 | 35篇 |
1999年 | 43篇 |
1998年 | 60篇 |
1997年 | 51篇 |
1996年 | 42篇 |
1995年 | 35篇 |
1994年 | 35篇 |
1993年 | 29篇 |
1992年 | 22篇 |
1991年 | 29篇 |
1990年 | 18篇 |
1989年 | 35篇 |
1988年 | 31篇 |
1987年 | 52篇 |
1986年 | 30篇 |
1985年 | 29篇 |
1984年 | 20篇 |
1983年 | 13篇 |
1982年 | 22篇 |
1981年 | 17篇 |
1979年 | 13篇 |
1978年 | 19篇 |
1977年 | 12篇 |
1976年 | 17篇 |
1975年 | 13篇 |
1969年 | 10篇 |
1968年 | 11篇 |
1967年 | 11篇 |
1966年 | 16篇 |
排序方式: 共有1774条查询结果,搜索用时 15 毫秒
1.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献
2.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
3.
4.
5.
6.
W Fehske J K?hler D Kessel R Rabahieh A Hagendorff K Stevens A Niedeggen B Lüderitz 《Zeitschrift für Kardiologie》1992,81(11):627-635
The normal leakage flow in modern technical heart valve prostheses can be visualized by color-coded Doppler-echocardiography, provided that an adequate ultrasonic image quality can be achieved. Sometimes it may be difficult, however, to distinguish such a normal leakage flow from pathological regurgitation. We therefore mounted new specimens of five different types of prostheses (Bj?rk-Shiley monostrut, Medtronic-Hall, Omnicarbon, Saint Jude Medical, Duromedics) into an invitro model, where the leakage flows could directly be visualized as emerging water jets. When the system was completely filled, the jets could also be registered by two-dimensional Doppler-echocardiography. For each valve, characteristic patterns for the localization of the principal jets were found. Besides the relative broad central jet in the Medtronic-Hall valve, all other jets arose mainly at the ring. They were detected at the hinges or the basis of the larger struts, respectively, and with asymmetrical mono-disc valves at the side of the smaller opening. The length and the orientation of the jets were found to change significantly with minimal variations of the position of the closing discs. This variability could be confirmed, when in a separate model the overall leakage flows were repeatedly measured. For patient examinations it seems useful to refer mainly to the localization of the jet origins. The comparison with reference values of jet-dimensions in Doppler images will rarely enable the examiner to distinguish between normal and pathological jets. 相似文献
7.
D L Cohen L B McCullough R W Kessel A Y Apostolides E R Alden K J Heiderich 《Journal of medical education》1987,62(10):789-798
When medical students become involved in patient care, concerns are raised that have ethical and possibly legal implications. In order to determine compliance with the guidelines of the U.S. government and the Joint Committee on Accreditation of Hospitals pertaining to informed consent, the authors conducted a study of hospital administrators, medical school department chairpersons, and medical school deans (with response rates ranging from 82.3 to 95.1 percent) concerning policies on student involvement in patient care. The results show that only 37.5 percent of all responding teaching hospitals specifically informed patients that students would be involved in care. Only 51 percent of the responding medical schools that specifically gave their students instruction or guidance on initial patient interaction as a matter of policy insisted that their students introduce themselves as students and clarify their role in patient care. The authors conclude that medical educators' compliance with the ethical requirements of informed consent is incomplete. 相似文献
8.
L S Taitz J M King J Nicholson M Kessel 《British medical journal (Clinical research ed.)》1987,294(6579):1074-1076
The employment state of men living in the homes of children at the time that child abuse was diagnosed was determined. The series included a wide range of abuse, including non-accidental injury, failure to thrive, neglect, and emotional deprivation. Two cohorts of children seen during 1974-9 and 1980-5 were compared; these periods were chosen because a large increase in unemployment began in Sheffield in 1980. Although the proportion of the men without work was significantly increased during the second period, this increase could not be ascribed to the rise in either long term or short term unemployment among those who had previously been in regular employment. It was accounted for by a rise in the proportions of single parent families and families in which the resident man had never had regular employment. This may reflect an increase in pregnancies among young mothers. There was no evidence to support the belief that the loss of a job in otherwise stable families leads to an increase in child abuse. 相似文献
9.
N Kessel 《Journal of the Royal Society of Medicine》1997,90(6):301-302
10.
Four hundred fifteen patients with metastatic breast cancer with known hormone receptor status received primary treatment with tamoxifen. Measured values for the estrogen receptor (ER, i.e., with estrogen binding) followed a continuous distribution (range, 3 to 1000 fmol/mg of protein). These values correlated positively with age. The response to treatment with tamoxifen correlated with the ER level, with response rates of approximately 80% when the ER level was greater than 30.1 fmol/mg of protein. Two hundred eighteen (218 of 415, 52%) patients had progesterone receptor (PR) values greater than 10 fmol/mg. The PR positivity correlated with the ER level. Patients with PR levels greater than 10 fmol/mg of protein (124 of 226, 55%) had a significantly higher response rate than those with values less than 10 fmol/mg of protein (45 of 189, 24%). However, in a multivariate analysis including both receptor levels, age, site, and number of metastases, only the ER level was significant in predicting the response to treatment with tamoxifen. A quantitative estimation of the ER level thus is the best predictor of response to hormonal treatment with tamoxifen for advanced breast cancer. 相似文献