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   2645篇
  免费   125篇
  国内免费   19篇
耳鼻咽喉   24篇
儿科学   45篇
妇产科学   28篇
基础医学   270篇
口腔科学   30篇
临床医学   161篇
内科学   905篇
皮肤病学   37篇
神经病学   171篇
特种医学   184篇
外科学   397篇
综合类   9篇
预防医学   66篇
眼科学   43篇
药学   144篇
中国医学   4篇
肿瘤学   271篇
  2023年   23篇
  2022年   35篇
  2021年   90篇
  2020年   50篇
  2019年   52篇
  2018年   58篇
  2017年   64篇
  2016年   59篇
  2015年   61篇
  2014年   90篇
  2013年   99篇
  2012年   160篇
  2011年   184篇
  2010年   130篇
  2009年   62篇
  2008年   185篇
  2007年   165篇
  2006年   170篇
  2005年   167篇
  2004年   178篇
  2003年   160篇
  2002年   128篇
  2001年   28篇
  2000年   31篇
  1999年   27篇
  1998年   42篇
  1997年   28篇
  1996年   23篇
  1995年   14篇
  1994年   23篇
  1993年   9篇
  1992年   23篇
  1991年   16篇
  1990年   10篇
  1989年   13篇
  1988年   10篇
  1987年   13篇
  1986年   13篇
  1985年   11篇
  1984年   12篇
  1983年   7篇
  1980年   5篇
  1979年   7篇
  1978年   4篇
  1977年   8篇
  1976年   3篇
  1974年   3篇
  1973年   4篇
  1969年   6篇
  1968年   6篇
排序方式: 共有2789条查询结果,搜索用时 15 毫秒
41.
We have found that steroid bolus withdrawal prior to graft reperfusion increased the incidence of acute cellular rejection (ACR). This study aims to clarify how initial steroid bolus (ISB) injection at reperfusion influences the kinetics of CD8(+) alloreactive immune responses immediately after living donor liver transplantation (LDLT). A total of 49 hepatitis C virus (HCV)-infected recipients were classified into 3 groups according to hierarchical clustering by preoperative CD8(+)CD45 isoforms. The naive T cell proportion was considerably higher in Group I than in Groups II and III, whereas Group II recipients had the highest effector memory (EM) T cells and Group III the highest effector T cells. The frequency of ACR was significantly higher in recipients without ISB than in those with ISB. In particular, the ACR rates were the highest in Group II without ISB. Following ISB, the proportion of effector T cells was promptly upregulated within 6 hours after graft reperfusion, simultaneously with the upregulation of CD27(-)CD28(-) subsets, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha and perforin expression, which significantly correlated with increasing interleukin (IL)-12 receptor beta 1 cells. These were then downregulated to below preoperative levels by tacrolimus (Tac) administered at 24 hours. These changes did not occur in the absence of ISB. In Group II without ISB, the downregulation of IL-12Rbeta1(+) cells was the greatest, consistent with the highest rates of ACR and mortality (60%). In conclusion, ISB must be done in place, especially in Group II with preexisting high EM T cells, to enable the development of early allograft acceptance.  相似文献   
42.
Differentiated thyroid cancer sometimes shows microscopic vascular invasion but rarely causes a tumor thrombus in a great vein. A preoperative diagnosis of the latter condition is difficult if a patient does not have any overt symptoms, but it is important for operative planning. We encountered a 26-year-old woman with papillary thyroid cancer and a tumor thrombus extending from the brachiocephalic vein to the superior vena cava. The tumor was successfully treated by surgical resection. To our knowledge only 19 such cases have so far been reported. We herein report our case, review the literature, and discuss the associated diagnostic problems and treatments including such areas as age, gender, symptoms, pathology, extension, and outcome. Received: October 20, 2000 / Accepted: July 17, 2001  相似文献   
43.
Living donor liver transplantation (LDLT) for patients with portal vein thrombosis (PVT) involves technical difficulty. The aim of this research was to analyze their preoperative diagnosis of PVT, operative procedures, and postoperative courses of patients with preoperative PVT. Thirty-nine patients of 404 adult patients (9.7%) undergoing LDLT in our hospital from 1996 June to 2004 December had PVT at their transplantation. Twenty-nine patients had intractable ascites, 21 had gastrointestinal bleeding, and 18 had encephalopathy. The thrombus was located in the portal trunk in 23, in the portal trunk and superior mesenteric vein (SMV) in 7, and developed into the SMV and the splenic vein in 8. The occlusive grade was partial in 29, and complete in 10 patients. The thrombus was removed by a simple technique, and eversion and/or incision technique, or total removal of the portal vein (PV). The PV was reconstructed with the thrombectomized native PV, with an interposed vein graft, or porto-caval hemitransposition. Advanced PVT had a significant impact on blood loss and hospital mortality. Three out of 10 patients with residual PVT required radiological and/or surgical intervention after transplantation. In conclusion, thorough planning is essential for a successful LDLT outcome for patients with preexisting PVT.  相似文献   
44.
BACKGROUND: Whether hepatitis C virus recurrence occurs earlier and with greater severity for living donor liver transplantation (LDLT) than for deceased donor liver transplantation (DDLT) has recently become a subject of debate. METHODS: We retrospectively evaluated clinical outcomes for a cohort of 91 HCV-positive patients who underwent LDLT at Kyoto University with a median follow-up period of 25 months. RESULTS: Overall 5-year patient survival for HCV patients was similar to that for non-HCV patients (n=209) who underwent right-lobe LDLT at our institute (69% vs. 71%). Survival rate of patients without HCC (n=34) tended to be better than that of patients with HCC (n=57) (82% vs. 60%, P=0.069). According to annual liver biopsy, rate of fibrosis progression to stage 2 or more (representing significant fibrosis) was 39% at 2 years after LDLT. Univariate analysis showed that female recipient and male donor represented significant risk factors for significant fibrosis. Progression to severe recurrence (defined as the presence of liver cirrhosis (F4) in a liver biopsy and/or the development of clinical decompensation) was observed in five patients. CONCLUSIONS: Postoperative patient survival was similar for HCV-positive and -negative recipients in our adult LDLT series. Rates of progression to severe disease due to HCV recurrence seemed comparable between our LDLT recipients and DDLT recipients described in the literature. Although longer-term follow-up is required, our results suggest that LDLT can produce acceptable outcomes also for patients suffering from HCV-related cirrhosis.  相似文献   
45.
To analyze human herpesvirus 6 (HHV-6) infection in adult living related liver transplantation, we performed a virological analysis, including viral isolation, serological assay, and real-time polymerase chain reaction, of serially collected blood samples from 67 recipients. In addition, cytokine levels were measured to determine their role in viral reactivation. HHV-6 was isolated from only 4 recipients (6.0%), and viral DNA was detected in 15 (22.4%) of the 67 recipients. A significant increase in HHV-6 immunoglobulin G antibody titers was observed in 19 (28.4%) of the 67 recipients. Finally, 26 recipients (38.8%) had HHV-6 reactivation 2-6 weeks after transplantation. HHV-6 associated clinical features were analyzed in the 17 recipients presenting with either viremia or DNAemia. Two recipients with viremia and 3 recipients with DNAemia had unexplained fever at the time of viral infection. An increase in aminotransferase levels was observed in 2 recipients with viremia and 3 recipients with DNAemia. Recipients with liver cirrhosis caused by hepatitis B virus or hepatitis C virus infection as the underlying disease were more likely to have HHV-6 infection (P = 0.025). Mortality at the last follow-up in recipients with HHV-6 reactivation was significantly higher than in those without viral reactivation (P = 0.0118). Plasma interleukin-6 levels were significantly higher in the recipients with HHV-6 viremia than in the recipients without viremia at 4 weeks post-transplant (P = 0.0411). Moreover, tumor necrosis factor alpha levels were also higher in recipients with HHV-6 viremia (P < 0.0001) or reactivation (P = 0.0011) than in recipients without viremia or reactivation 4 weeks post-transplant.  相似文献   
46.
A 57-year-old female was transferred to our hospital because of sudden dyspnea. She was hypotensive and hypoxic. Acute massive pulmonary thromboembolism was detected by echocardiography and computed tomography (CT). Before the operation, she fell into severe shock and needed cardiopulmonary resuscitation. We applied percutaneous cardiopulmonary support (PCPS), and performed emergency open embolectomy under total cardiopulmonary bypass. Because of the right ventricular failure, she could not be weaned from total cardiopulmonary bypass. PCPS was required again and used continuously during postoperative management. Her cardiopulmonary state improved gradually. PCPS was stopped at 6 days after surgery, and she was extubated at 14 days after surgery. PCPS was very useful for resuscitation and stabilization of the cardiopulmonary function for acute massive pulmonary thromboembolism perioperatively.  相似文献   
47.
The purpose of this study is to compare clinical outcomes of left ventricular assist device (LVAD) patients with device thrombosis who underwent device exchange (DE) or medical therapy (MT) alone. Consecutive patients undergoing LVAD implant between July 2008 and December 2017 were included. Device thrombosis was diagnosed with comprehensive assessments including ramp test, laboratory data, device parameters, and clinical presentations. First, MT was initiated in all patients. After MT, DE was considered if device thrombosis was refractory to initial MT, and it caused end-organ impairment and/or hemodynamic instability. Among 319 consecutive LVAD patients, 43 patients (13.5%) were diagnosed with device thrombosis. DE was performed in 28 patients (DE group); device explant was performed in 1 patient. MT was continued in 14 patients (MT group). In-hospital mortality was significantly lower in the DE group than the MT group (3.6% [1/28] vs. 28.6% [4/14], = .0184). One-year survival was significantly better in the DE group (74.0% vs. 30.1%; log-rank = .001), and freedom from cerebrovascular accident (CVA) at 1 year was greater in the DE group (87.1% vs. 47.7%; log-rank = .004). DE was associated with improved 1-year survival and fewer CVAs. Surgical intervention, if feasible, is recommended for LVAD device thrombosis.  相似文献   
48.
49.
Journal of Gastroenterology - Following liver transplantation (LT), allograft liver failure can be developed by various causes and requires re-LT. Hence, this study aimed to clarify the...  相似文献   
50.
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