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   7326篇
  免费   408篇
  国内免费   46篇
耳鼻咽喉   84篇
儿科学   183篇
妇产科学   142篇
基础医学   899篇
口腔科学   171篇
临床医学   506篇
内科学   2078篇
皮肤病学   238篇
神经病学   620篇
特种医学   150篇
外科学   1168篇
综合类   47篇
一般理论   6篇
预防医学   432篇
眼科学   85篇
药学   483篇
中国医学   12篇
肿瘤学   476篇
  2023年   43篇
  2022年   119篇
  2021年   172篇
  2020年   97篇
  2019年   137篇
  2018年   172篇
  2017年   139篇
  2016年   145篇
  2015年   167篇
  2014年   248篇
  2013年   290篇
  2012年   445篇
  2011年   452篇
  2010年   289篇
  2009年   238篇
  2008年   436篇
  2007年   464篇
  2006年   412篇
  2005年   477篇
  2004年   449篇
  2003年   426篇
  2002年   368篇
  2001年   163篇
  2000年   152篇
  1999年   138篇
  1998年   76篇
  1997年   51篇
  1996年   53篇
  1995年   54篇
  1994年   47篇
  1993年   35篇
  1992年   82篇
  1991年   66篇
  1990年   70篇
  1989年   48篇
  1988年   46篇
  1987年   48篇
  1986年   30篇
  1985年   38篇
  1984年   36篇
  1983年   30篇
  1982年   31篇
  1981年   16篇
  1979年   21篇
  1977年   19篇
  1975年   15篇
  1972年   15篇
  1971年   17篇
  1970年   18篇
  1969年   20篇
排序方式: 共有7780条查询结果,搜索用时 15 毫秒
1.
2.
3.

Background  

Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure.  相似文献   
4.
1. The authors investigated the effect of two extrahepatic cholestasis models (one by bile duct ligation and the other by choledocho-jugular fistula) on the hepatic clearance of horseradish peroxidase in male Sprague-Dawley rats divided into four groups. 2. In groups A (n = 5 rats) and B (n = 5), bile duct ligation was performed, while a choledocho-jugular fistula was created in groups C (n = 5) and D (n= 7). A 10 mg intravenous bolus of horseradish peroxidase was injected after 24 h (groups A and C), 48 h (groups B and D) or 1 h (Group E; five sham-operated rats). Serum and bile samples were then serially collected for 2 h. 3. In all groups, serum horseradish peroxidase levels increased soon after injection and then rapidly decreased, the curves being similar. Biliary excretion increased for 30 min and then slowly decreased. The highest horseradish peroxidase biliary concentrations and outputs were found in Group B followed by Group A; both groups had significantly higher levels than Group E. No difference was found between horseradish peroxidase biliary excretion of groups C and D and that of sham-operated rats. 4. When each group was considered separately, sampling times correlated with the corresponding ratios of bile/ plasma HRP. Significant differences were found between the relative slopes of groups A, B and E, but not between those of groups C, D and E. 5. In conclusion, bile duct obstruction greatly affects the plasma-bile transfer of fluid phase markers, such as horseradish peroxidase, while single retention, caused by choledocho-jugular fistula, has no influence. The increased biliary hyperpressure related to the duration of cholestasis may account for the degree of horseradish peroxidase transfer which, in turn, probably depends on an enhanced paracellular passage.  相似文献   
5.
After total gastrectomy, the ileocecal graft may act as a reservoir and protect against reflux but give rise to transposition of the ileum and cause possible changes in bile acid metabolism and nutrition. This study compared the ileocecal graft and jejunal pouch. Male Wistar rats weighing 265 +/- 22 g were submitted to sham operation (S), ileocecal interposition graft (IIG), and jejunal pouch interposition graft (JP) after total gastrectomy. Eight weeks later, the esophagus was examined for evidence of esophagitis. Nutritional biochemistry and weight profile were documented preoperatively and 8 weeks after surgery. The oral glucose tolerance test was performed. Thirty-three rats were operated on and 30 survived for 8 weeks. Esophagitis occurred in seven JP rats. Body weight was significantly higher in IIG than in JP rats (p < .05). Normal glucose tolerance to intragastric glucose load was observed in sham and operated rats. JP rats had a significant decrease in serum albumin, glucose, transferrin, hemoglobin, iron, folate, and calcium, compared to sham (p < .05). Cobalamine was significantly lower in IIG rats than in JP rats (p < .05). In the IIG and JP groups, serum/hepatic total bile acid did not differ significantly from preoperative and sham values. In conclusion, the IIG interposition graft in rats prevented esophagitis, preserved nutrition, and did not interfere with enterohepatic total bile acid circulation.  相似文献   
6.
Avoidance of corticosteroids could be beneficial after pediatric liver transplantation (LTx). To test this hypothesis, we performed a randomized prospective study to compare immunosuppression with tacrolimus (TAC) and steroids versus TAC and basiliximab (BAS) after pediatric LTx. Seventy-two patients were recruited, 36 receiving TAC and steroids and 36 TAC and BAS. The primary endpoint was the occurrence of the first rejection episode. Secondary endpoints were the cumulative incidence and severity of rejection, patient and graft survival, and incidence of adverse events. Overall 1-year patient and graft survival rates were 91.4% and 85.5% in the steroid group, and 88.6% and 80% in the BAS group (p = NS). Patients free from rejection were 87.7% in the BAS group and 67.7% in the steroid group (p = 0.036). The use of BAS was associated with a 63.6% reduction in incidence of acute rejection episodes. Overall incidence of infection was 72.3% in the steroid group and 50% in the BAS group (p = 0.035). We conclude that the combination of TAC with BAS is an alternative to TAC and steroid immunosuppression in pediatric LTx, which allows for a significant reduction in the incidence of acute rejection and infectious complications.  相似文献   
7.
8.
9.
Pietro Rubegni  MD    Sara Poggiali  MD    Aldo Cuccia  MD    Maurizio Biagioli  MD    Michele Fimiani  MD 《Dermatologic surgery》2004,30(12P2):1539-1542
Background. Striated palmoplantar keratoderma or Brunauer-Fohs-Siemens syndrome is a very rare, focal, nonepidermolytic palmoplantar keratoderma with autosomal inheritance. Unlike other palmoplantar keratodermas, no association with visceral or skin cancer has ever been reported.
Objective. We report a case of malignant melanoma arising in the hyperkeratotic lesions on the right heel of a patient with striated palmoplantar keratoderma. The lesion was completely excised; our patient also underwent sentinel lymph node biopsy and then was treated with high-dose interferon adjuvant therapy.
Methods. Sentinel lymph node biopsy incision was made in elliptical fashion, long enough to harvest a full-thickness skin graft to cover the wide local excision defect. The skin graft was defatted by sharp dissection. Several perforations were made in graft and it was secured in place with sutures and bolster dressing.
Results. At follow-up, the grafted skin showed hyperkeratotic changes but no local or systemic signs of the disease was observed.
Conclusion. The association between striated palmoplantar keratoderma and acral melanoma is discussed.  相似文献   
10.
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