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   989篇
  免费   67篇
  国内免费   45篇
耳鼻咽喉   4篇
儿科学   49篇
妇产科学   10篇
基础医学   111篇
口腔科学   14篇
临床医学   186篇
内科学   230篇
皮肤病学   10篇
神经病学   43篇
特种医学   130篇
外科学   96篇
综合类   23篇
预防医学   75篇
眼科学   10篇
药学   68篇
中国医学   1篇
肿瘤学   41篇
  2021年   4篇
  2019年   11篇
  2018年   9篇
  2017年   7篇
  2016年   10篇
  2015年   14篇
  2014年   21篇
  2013年   31篇
  2012年   49篇
  2011年   38篇
  2010年   45篇
  2009年   35篇
  2008年   35篇
  2007年   79篇
  2006年   31篇
  2005年   35篇
  2004年   29篇
  2003年   29篇
  2002年   22篇
  2001年   18篇
  2000年   28篇
  1999年   17篇
  1998年   49篇
  1997年   33篇
  1996年   44篇
  1995年   26篇
  1994年   17篇
  1993年   23篇
  1992年   19篇
  1991年   14篇
  1990年   24篇
  1989年   38篇
  1988年   39篇
  1987年   27篇
  1986年   21篇
  1985年   15篇
  1984年   16篇
  1983年   12篇
  1982年   12篇
  1981年   6篇
  1980年   7篇
  1979年   5篇
  1978年   8篇
  1977年   13篇
  1976年   7篇
  1975年   7篇
  1972年   6篇
  1971年   3篇
  1967年   2篇
  1966年   2篇
排序方式: 共有1101条查询结果,搜索用时 15 毫秒
1.
The urological complications of 320 consecutive renal transplants performed at our institution between October 17, 1985 and November 10, 1989 are reviewed. The Leadbetter-Politano technique of ureteroneocystostomy was used in the first 160 patients (group 1) and an anterior extravesical technique modified from the methods of Witzel, Sampson and Lich was performed in the second 160 patients (group 2). Urological complications occurred in 15 patients (9.4%) in group 1 and 6 (3.7%) in group 2 (p = 0.04). Ureterovesical junction obstruction occurred in 6 patients (3.7%) in group 1 and 1 (0.6%) in group 2 (p = 0.05). Complications of leakage, ureteral necrosis and ureteral stricture were comparable in the 2 groups. Therefore, we advocate the use of the anterior extravesical technique over Leadbetter-Politano ureteral reimplantation based on the lower incidence of urological complications and various technical advantages, including less operative time, avoidance of a separate cystotomy, less hematuria and ability to use short donor ureters.  相似文献   
2.
We report 2 cases of leiomyosarcoma of the bladder that occurred after long-term cyclophosphamide chemotherapy for lupus nephritis and rheumatoid arthritis. One patient had a tumor at the end of an 11-year course of chemotherapy and 1 approximately 7 years after completing a 7-year course of chemotherapy. Patient 1 underwent left partial cystectomy and patient 2 underwent cystectomy with ileal conduit urinary diversion. In patient 1 the tumor was a typical leiomyosarcoma and patient 2 had a myxoid variant. Both patients were free of disease at 4 months and 3 years, respectively. Whereas previous reports of the carcinogenic effects of cyclophosphamide have been questioned, since the induced tumors occurred in patients being treated for other neoplasms (lymphoproliferative and myeloproliferative disorders), the disease in both of our patients followed cyclophosphamide therapy for nonneoplastic disorders.  相似文献   
3.
4.
5.
We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.  相似文献   
6.
Whereas water loss in land living animals occurs continuously, water intake takes place discontinuously. At the normal operating set point of plasma osmolality, urine is more concentrated than plasma due to secretion of vasopressin. Thus animals operate around a state of mild dehydration. As water loss occurs, the severity of dehydration and thirst increase in intensity and at some point water intake occurs. Sufficient water is consumed to return plasma osmolality to the normal operating set point. Food intake and water balance are interdependent as food provides the osmoles which determine obligatory renal solute excretion. When dry food with the same osmotic content was substituted for canned food (water content 74%), dogs increased water intake from 24.2 +/- 4.3 to 62.2 +/- 8.8 ml/kg. Urine output and urine osmolality were unchanged, as under conditions of normal hydration, near maximal urine concentration is achieved. Changing water intake is the only available variable to maintain water balance. During water deprivation, the major renal mechanism appears to be natriuresis. In rehydration, satiety mechanisms ensure appropriate water intake and renal sodium conservation restores sodium balance.  相似文献   
7.
8.
Effects of the benzodiazepine receptor antagonist ZK 93 426 were examined in two groups of rats with long lasting radial maze impairments caused by either ibotenic acid lesions to cholinergic forebrain projections or 28 weeks of alcohol treatment. Animals were trained on the 8-arm radial maze prior to ibotenic acid treatment or following chronic alcohol treatment. Spatial and associative working and reference memory were investigated in parallel. Lesioned rats showed high error rates in all aspects of memory, but particularly in spatial working memory, whilst error rates in alcohol-treated rats were low and uniform. ZK 93 426 improved performance in both experiments. In lesioned rats working memory errors were selectively decreased, in line with evidence that ZK 93 426 enhances attention. However in alcohol-treated rats both reference and working memory errors were reduced to control level, suggesting that these animals primarily showed a mild attentional deficit. Alcohol treatment and lesions were both found to reduce cortical choline acetyltransferase activity, but in view of the non-specificity of alcohol or ibotenic acid to cholinergic neurons and the wide distribution of the GABA-BZ receptor complex, interactions of ZK 93 426 with other systems cannot be ruled out.  相似文献   
9.
10.
Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.   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