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   19789篇
  免费   905篇
  国内免费   111篇
耳鼻咽喉   270篇
儿科学   378篇
妇产科学   213篇
基础医学   2248篇
口腔科学   567篇
临床医学   1335篇
内科学   5069篇
皮肤病学   410篇
神经病学   1248篇
特种医学   776篇
外科学   3746篇
综合类   93篇
一般理论   2篇
预防医学   597篇
眼科学   219篇
药学   1404篇
中国医学   56篇
肿瘤学   2174篇
  2023年   92篇
  2022年   188篇
  2021年   411篇
  2020年   214篇
  2019年   266篇
  2018年   345篇
  2017年   250篇
  2016年   343篇
  2015年   349篇
  2014年   455篇
  2013年   580篇
  2012年   977篇
  2011年   1150篇
  2010年   694篇
  2009年   557篇
  2008年   1026篇
  2007年   1069篇
  2006年   1075篇
  2005年   1081篇
  2004年   1012篇
  2003年   880篇
  2002年   907篇
  2001年   484篇
  2000年   561篇
  1999年   470篇
  1998年   257篇
  1997年   225篇
  1996年   201篇
  1995年   150篇
  1994年   148篇
  1993年   141篇
  1992年   394篇
  1991年   353篇
  1990年   339篇
  1989年   347篇
  1988年   332篇
  1987年   319篇
  1986年   268篇
  1985年   262篇
  1984年   187篇
  1983年   177篇
  1982年   73篇
  1981年   79篇
  1979年   112篇
  1978年   85篇
  1977年   89篇
  1974年   80篇
  1972年   74篇
  1970年   80篇
  1969年   77篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
21.
BACKGROUND: The objective of this study was to evaluate the efficacy and safety of first-line high-dose chemotherapy (HDCT) combined with peripheral blood stem cell transplantation (PBSCT) for patients with advanced extragonadal germ cell tumors (EGGCT). METHODS: Six male patients with advanced non-seminomatous EGGCT were treated with HDCT combined with PBSCT following 2-3 cycles of conventional-dose induction chemotherapy. The regimens used for HDCT were carboplatin, etoposide and ifosfamide (ICE) in five patients and ICE plus paclitaxel (T-ICE) in one patient, and that for induction therapy was cisplatin, etoposide and bleomycin (PEB) in all patients. As a rule, HDCT was continuously administered until alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin normalized (beta-HCG). RESULTS: Following 1-6 courses of HDCT (median, 4 courses), beta-HCG and AFP were normalized in all patients, and five and one patient were diagnosed as showing partial remission and stable disease, respectively. Five patients underwent surgical resection of residual tumors after HDCT, yielding necrotic tissue in two, mature teratoma in two, and viable cancer tissue in one, and the surgical margin was negative in all patients. At a median follow-up of 36 months, five patients were alive and disease-free, whereas the remaining one died of disease progression. Although all patients had grade 3 hematological toxicity, there was no treatment-related death by combining PBSCT. CONCLUSIONS: First-line HDCT with PBSCT could be safely administered to patients with advanced EGGCT, and the antitumor effect of this treatment was comparatively favorable. First-line HDCT therefore may represent an attractive option for patients with advanced EGGCT.  相似文献   
22.
OBJECTIVES: Vesicoureteral reflux (VUR) is the most common congenital urinary tract anomaly. This disease can pose a major threat to the kidneys as twenty percent of patients with endstage renal disease are reported to have VUR. Although genetic studies for uroplakin III (UPIII) have been reported recently, no study has focused on UPIII gene expression in VUR patients. We describe here the up-regulation of UPIII mRNA in exfoliated urinary cells from primary VUR patients. METHODS: A real-time RT-PCR for UPIII mRNA was performed on exfoliated urothelial cells from 18 primary VUR and 38 control samples. UPIII mRNA copies were calculated for each sample. The statistical differences were assessed by the Mann-Whitney U test. Receiver operator characteristic curves were constructed for analysis of the diagnostic values. RESULTS: UPIII mRNA was found to be up-regulated to a greater extent in VUR than in control exfoliated urinary cells (mean +/- SE: 497.0 +/- 178.5 copies vs. 69.0 +/- 10.0 copies, respectively, P < 0.001). In evaluating the measurement of urinary UPIII mRNA as a screening test for VUR, the sensitivity was 77.8% and the specificity was 76.3% by the best diagnostic cutoff point. CONCLUSIONS: This is the first report demonstrating up-regulation of UPIII in mRNA levels in VUR patients. We submit that the quantitative measurement of urinary UPIII mRNA has a potential of developing into the first non-invasive screening test for VUR.  相似文献   
23.
Intravesical instillation of anti-cancer drugs for superficial urinary bladder cancer is generally carried out with the aim of prophylaxis against recurrence and chemotherapy against tumor. But since sensitivity of tumor cells to each anti-cancer drug differs individually, the anti-cancer drug to be used should also be decided individually. We selected a new sensitivity test, ATP-sensitivity-assay, which measures intracellular adenosine triphosphate (ATP) volume by Luciferin-Luciferase reaction, for the decision of the anti-cancer drug. In this paper, we evaluated the direct anti-tumor activity of the drugs that were decided by ATP-sensitivity-assay of intravesical chemotherapy. Six drugs, that are Doxorubicin (ADM), Mitomycin C (MMC), Pirarubicin (THP-ADM), Cytarabine (Ara-C), Bleomycin (BLM) and Cisplatin (CDDP) were tested in this research and size of tumors of six patients reduced to 34-93% after 6 times' installation. A woman got cystitis induced by ADM after 3 times' instillation but instillation was completed. ATP-sensitivity-assay is useful for deciding the anti-cancer drugs for intravesical chemotherapy and prophylaxis for superficial bladder cancer.  相似文献   
24.
We have used recombinant human erythropoietin (rEPO) in order to prevent patients from developing anemia following preoperative autologous blood preservation. Thereby, we have been able to reduce intraoperative homologous blood transfusion during cardiac operations. In June and July, 1989, six middle-aged selective patients received rEPO (200 IU/kg) intravenously every other day starting from fifteen days before the day of their operations. One unit (200 ml) of autologous blood was drawn and preserved every few days. However, no significant differences were observed in red cell counts, hematocrit, hemoglobin and serum protein levels between before and after preservation. Not only preoperative autologous blood preservation with provision of rEPO, but also using the intraoperative autotransfusion system enabled us to perform cardiac operations on 5 out of 6 patients without any homologous blood transfusion. None of the six patients exhibited any undesirable effects due to rEPO administration. Their postoperative courses were excellent.  相似文献   
25.
26.
27.
28.
29.
Hepatocyte regeneration has been widely investigated, with the mitotic index and the incorporation of [3H]thymidine being used as regeneration markers. We focused on the induction of DNA replication enzymes, particularly DNA polymerases (pol) α, δ, and ε. Using rat models, we have shown that the activity of pol α in crude liver extract well represents the regenerating capacity of hepatocytes. Using pol α as an indicator, we analyzed liver regeneration in rat models under various conditions: obstructive jaundice, external or internal biliary drainage, and the obstruction of portal vein branches. It has been revealed that the ligation of the common bile duct alone induces a certain amount of hepatocyte proliferation. It was striking that external biliary drainage suppressed regeneration capacity in cholestatic rat liver after partial hepatectomy. The strong regeneration in nonligated lobes induced by portal branch ligation was similar to the liver regeneration seen after partial hepatectomy with respect to the induction of DNA polymerases. Taken together, the aspects of DNA replication, particularly the induction of DNA polymerases, may contribute to shedding new light on the regeneration of human liver. This work was supported in part by a Grant-in-Aid for General Scientific Research and for Cancer Research from the Ministry of Education, Science and Culture, Japan, and by grants from the Uehara Memorial Foundation  相似文献   
30.
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