首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1211篇
  免费   59篇
  国内免费   1篇
耳鼻咽喉   33篇
儿科学   12篇
妇产科学   16篇
基础医学   157篇
口腔科学   81篇
临床医学   81篇
内科学   333篇
皮肤病学   11篇
神经病学   88篇
特种医学   86篇
外科学   169篇
综合类   2篇
预防医学   29篇
药学   56篇
肿瘤学   117篇
  2022年   8篇
  2021年   22篇
  2020年   9篇
  2019年   12篇
  2018年   8篇
  2017年   11篇
  2016年   16篇
  2015年   19篇
  2014年   31篇
  2013年   21篇
  2012年   47篇
  2011年   31篇
  2010年   31篇
  2009年   35篇
  2008年   34篇
  2007年   55篇
  2006年   44篇
  2005年   58篇
  2004年   60篇
  2003年   58篇
  2002年   72篇
  2001年   48篇
  2000年   43篇
  1999年   40篇
  1998年   18篇
  1997年   20篇
  1996年   17篇
  1995年   14篇
  1994年   9篇
  1993年   7篇
  1992年   42篇
  1991年   18篇
  1990年   36篇
  1989年   34篇
  1988年   39篇
  1987年   15篇
  1986年   26篇
  1985年   23篇
  1984年   12篇
  1983年   14篇
  1979年   10篇
  1978年   9篇
  1977年   8篇
  1976年   7篇
  1973年   9篇
  1971年   12篇
  1969年   6篇
  1968年   7篇
  1967年   5篇
  1966年   7篇
排序方式: 共有1271条查询结果,搜索用时 0 毫秒
1.
2.
We report satisfactory results with a new operative treatment, conducted via an extensive anterolateral approach, involving 360 degree circumferential capsulotomy, for residual subluxation in congenital dislocation of the hip (CDH). Long-term radiographic results of this procedure (group A) were compared retrospectively with the results of partial capsulotomy (group B), which preserved the posteroinferior joint capsule. The mean center edge angle in group A (22.5°) was greater than that in group B (16.0°). Satisfactory results were achieved in 11 of 15 hips (73%) (Severin class I or II) in group A, and in 5 of 12 hips (42%) in group B. These results suggest that whole circumferential capsulotomy can remove obstacles to complete reduction, and that acetabular development can be expected in hips reduced by the procedure, without the performance of innominate osteotomy. We believe that our technique is a useful alternative for the treatment of residual subluxation in CDH.  相似文献   
3.
The correlation between kinetic metal behaviour and the degenerative process in the central nervous system (CNS) tissues of magnesium (Mg) deprived animals was examined, with particular reference to the levels and ratios of Mg, calcium (Ca), and aluminium (Al). Al content in the CNS tissue was high in the groups fed low Mg and low Mg + low Ca diets, as well as those supplemented with Al. In the group given a normal Mg, normal Ca with high Al diet, Al content in the CNS tissue showed no difference compared with that of the control group, although the concentration of Al in the serum was high. It was observed that Al content tended to rise with an increase in the Mg/Ca ratio in the CNS tissue. There was neither atrophy nor degeneration of the anterior horn cells of the spinal cord, nor demyelination of the pyramidal tract, which are characteristic of the pathology of amyotrophic lateral sclerosis. The cell body, nucleus, and nucleolus of the spinal neurones, however, appeared to diminish in size in the groups fed a low Mg diet and low Mg, low Ca with surplus Al diet. On the basis of these findings, it is speculated that Mg depletion, by increasing the Ca/Mg ratio in the CNS tissues, accelerates the uptake of Al into the brain, and this may later be involved in the development of the degenerative process.  相似文献   
4.
A 56-year-old man was admitted to our hospital with right chest pain. Chest X-ray, CT scan and MRI revealed a chest wall tumor and enlarged mediastinal lymph nodes. Percutaneous lung biopsy was performed, and the pathological diagnosis of pleomorphic rhabdomyosarcoma was obtained. The only significant abnormal laboratory finding was elevation of serum NSE (24.5 ng/ml). Although chemotherapy (VAC-ADM) and radiation therapy were performed, the patient died about 7 months after admission. To our knowledge, only 17 cases of chest wall rhabdomyosarcoma have been reported in Japan.  相似文献   
5.
Tumors in the area of the adrenal were detected by chance in two patients who underwent a regular physical check-up. On arteriography the tumors were found to be fed by the adrenal artery. The diagnosis was retroperitoneal schwannoma, but in both patients it was difficult to differentiate the schwannoma from an adrenal tumor preoperatively.  相似文献   
6.
7.
Expression of mRNAs encoding the erythroid-specific delta-aminolevulinate synthase (ALAS-E) and the nonspecific delta-aminolevulinate synthase (ALAS-N) were examined in murine Friend virus-transformed erythroleukemia (MEL) cells using nonradioactive in situ hybridization. Following dimethyl sulfoxide (DMSO) treatment, ALAS-E mRNA increased markedly, while ALAS-N mRNA did not increase in wild-type MEL cells. In contrast, in a DMSO-resistant clone of MEL cells, ALAS-E was not detectable before and after DMSO treatment. These findings suggest that ALAS-E and ALAS-N mRNAs are under separate controls and that the expression of ALAS-E mRNA is a critical event in erythroid differentiation.  相似文献   
8.
9.
Retrograde administration of cardioplegic solution via the right atrium with continuous cooling of the right ventricular cavity (right atrial perfusion cooling) was assessed for its protective effect in 12 dogs with occlusion of the right coronary artery subjected to global ischemia for 60 minutes. After an initial administration of 4 degrees C crystalloid cardioplegic solution by antegrade aortic perfusion, myocardial protection was established either by right atrial perfusion cooling (group I; n = 6) or by antegrade aortic perfusion alone (group II; n = 6). The right ventricular temperature was approximately 15 degrees C in group I and 20 degrees C in group II. After ischemia for 60 minutes, the adenosine triphosphate content of the right ventricular free wall was significantly higher in group I than in group II (24.4 +/- 1.45 versus 13.8 +/- 2.34 mumol/gm dry weight, p less than 0.05). The percent recovery of right ventricular contractility, which was evaluated by end-systolic pressure-volume relationships, was significantly better in group I at each reperfusion period (30 minutes: 130.0% +/- 9.6% versus 86.1% +/- 11.8%, p less than 0.05; 60 minutes: 159.6% +/- 12.9% versus 96.5% +/- 20.1%, p less than 0.05). Postischemic right ventricular stiffness (reciprocal value of compliance) increased in group II compared with group I, although the difference was not statistically significant. There were no major differences in percent recovery of the left ventricular end-systolic pressure-volume relationships between the two groups. The evidence suggests that the right atrial perfusion cooling method produces excellent right ventricular protection.  相似文献   
10.
OBJECTIVE: We aimed to determine whether or not the potential distribution of the sympathetic skin response (SSR) on the palm and dorsum of the hand can be described by an equivalent current dipole (ECD) as an SSR source model. METHODS: The SSR of 22 normal subjects were simultaneously obtained from two electrodes placed on the palm and the dorsum of hand, with an indifferent electrode on the thumbnail. We then measured the SSR potential distribution in 10 of the 20 subjects who had responded to stimulation with a clear dorsal SSR. To do this, 18 electrodes were attached to the palm and dorsum of the hand. SSR-evoking stimulation (sound, voice and rapid inspiration) were randomly delivered to the subject at time intervals of more than 1min to minimize the habituation effect. We estimated the ECD from the measured potential distribution. RESULTS AND CONCLUSIONS: The SSR-evoked by stimulation was negative in potential at the palmar sites of all 22 subjects, and was positive in potential at the dorsal sites of the hand in 20 of the 22 subjects. The SSR potential distribution, which was measured in 10 subjects, reached its maximum negative and positive potential near the base of the middle finger on the palm, and near the corresponding site on the dorsum of the hand, respectively. The SSR potential measured on the dorsum of the hand, however, was about 1/3 in amplitude of those on the palmar sites. These results suggest that the SSR source is located on the palm (probably the sweat glands) as confirmed by the estimated ECD (a negative pole on the palm and a positive pole on the dorsum of the hand). We speculate that the SSR may result from the potential difference caused by the Na(+) concentration gradient in the sweat, which results from intracanal reabsorption of Na(+). SIGNIFICANCE: The ECD resulting from the Na(+) concentration gradient within the canal of sweat glands is thought to be the source of the SSR from the negative pole on the palm to the positive pole on the dorsum.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号