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   1406401篇
  免费   97621篇
  国内免费   2302篇
耳鼻咽喉   20607篇
儿科学   46642篇
妇产科学   41131篇
基础医学   205485篇
口腔科学   38927篇
临床医学   118017篇
内科学   274348篇
皮肤病学   29817篇
神经病学   111600篇
特种医学   56784篇
外国民族医学   390篇
外科学   219412篇
综合类   27420篇
现状与发展   1篇
一般理论   335篇
预防医学   98665篇
眼科学   32615篇
药学   106658篇
  1篇
中国医学   2780篇
肿瘤学   74689篇
  2018年   14033篇
  2016年   12700篇
  2015年   14586篇
  2014年   19138篇
  2013年   28673篇
  2012年   40137篇
  2011年   42167篇
  2010年   24978篇
  2009年   23159篇
  2008年   41243篇
  2007年   44790篇
  2006年   45361篇
  2005年   44749篇
  2004年   42864篇
  2003年   41866篇
  2002年   41173篇
  2001年   62278篇
  2000年   63765篇
  1999年   54262篇
  1998年   15340篇
  1997年   13724篇
  1996年   13759篇
  1995年   12912篇
  1994年   12283篇
  1993年   11360篇
  1992年   42591篇
  1991年   41946篇
  1990年   41456篇
  1989年   40147篇
  1988年   37324篇
  1987年   36572篇
  1986年   34870篇
  1985年   33272篇
  1984年   24805篇
  1983年   21500篇
  1982年   12859篇
  1981年   11362篇
  1979年   23578篇
  1978年   16568篇
  1977年   14335篇
  1976年   13495篇
  1975年   14972篇
  1974年   17484篇
  1973年   16801篇
  1972年   16056篇
  1971年   14921篇
  1970年   13828篇
  1969年   13313篇
  1968年   12554篇
  1967年   11005篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
A true comparison of long-term medical and surgical treatment in gastro-oesophageal reflux disease (GORD) is impossible as few studies have been carried out with adequate randomisation of the patients and long-term evaluation of quality of life. In general the control of the reflux symptoms is roughly equal with medical and surgical treatment. However, surgery can cause other symptoms such as dysphagia or non-specific epigastric discomfort or pain in some patients, which reduces the overall efficacy in controlling the symptoms. Based on a cost utility analysis, Heudebert et al. came to the conclusion that medical treatment was their preferred strategy for most patients with severe erosive oesophagitis.  相似文献   
93.
The frequency and pathophysiology of freezing of gait (FoG) in atypical parkinsonism is unknown. We analysed the frequency of FoG in postmortem-confirmed atypical parkinsonian disorders (APD) comprising corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Sixty-six patients with pathologically confirmed APD (CBD, n = 13; DLB, n = 14; MSA, n = 15; PSP, n = 24) formed the basis for a multicenter clinicopathological study. Clinical features at first and last clinical visit were abstracted from patient records on standardized forms following strict instructions. At the first visit (median 36 months after symptom onset), 24% of APD had FoG (CBD, 8%; DLB, 21%; PSP, 25%; MSA, 40%). Logistic regression analysis showed a significant association of FoG and urinary incontinence (P = 0.04) at first visit. At last visit, 47% of APD had FoG (CBD, 25%; PSP, 53%; DLB, 54%; MSA, 54%). Clinicopathological correlation based on routine postmortem examination failed to identify a consistent neuropathological substrate of FoG. This study demonstrates that (1) FoG is common in APD, and (2) urinary incontinence is significantly associated with FoG in these disorders. Whether FoG and urinary incontinence share similar neuropathological substrates remains to be determined by future studies.  相似文献   
94.
95.
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans.  相似文献   
96.
Pulmonary valve insertion during reoperation for tetralogy of Fallot   总被引:1,自引:0,他引:1  
Our experience with pulmonary valve insertion during reoperation for residual lesions after initial open repair of tetralogy of Fallot in 15 patients is reported. Preoperatively, 14 patients were in moderate to severe congestive heart failure, and all 15 had decreased right ventricular (RV) function at cardiac catheterization. All 15 patients had pulmonary insufficiency but not as an isolated finding. The most common residual lesions encountered were ventricular septal defect in 9, tricuspid insufficiency in 11, and peripheral pulmonary arterial stenosis in 6. Tissue valves were inserted in all patients. Mean peak RV-left ventricular pressure ratio measured in the operating room decreased from 0.61 +/- 0.10 (+/- the standard deviation) to 0.47 +/- 0.17 (p less than 0.05). There were no operative deaths. At follow-up (mean, 33 months), all but 1 patient were in New York Heart Association Class I or II. Pulmonary valve insertion should be considered during reoperation for tetralogy of Fallot when pulmonary insufficiency and RV failure are present.  相似文献   
97.
98.
Median cervical cysts are congenital anomalies arising from remaining thyroglossal duct epithelium. A major problem in the surgical treatment of these cysts is the high frequency of recurrence. Embryonic considerations indicate an important causal role for the hyoid bone in these recurrences. We studied the relationship between operative techniques and the number of recurrences in 36 patients treated in our hospital. Fourteen patients sent from other hospitals had a recurrent fistula; in thirteen cases the hyoid bone was still in place. All patients who had the central part of the hyoid bone excised were cured. In 14 patients without adequate excisions of the hyoid bone we found four recurrences. To prevent recurrence a total excision of thyroglossal duct epithelium is necessary.  相似文献   
99.
Eighty-eight patients with blunt renal trauma were examined sonographically. Rupture of the kidney was diagnosed in 41 patients and contusion of the kidney in 45. The correlation between operative findings, sonography and urography showed positive sonographic findings to be correct in all patients with rupture of the kidney. In 4 patients with normal sonograms, the diagnosis of a contusion was based on the urographic results. Three patients underwent angiography. An intimal lesion was seen in 2 and a tear of the renal artery in 1. The results of our investigation suggest that sonography should be applied in the first place in the evaluation of blunt renal trauma. It is the investigation of choice during follow-up after surgical as well as conservative therapy.  相似文献   
100.
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