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   1159篇
  免费   62篇
  国内免费   3篇
耳鼻咽喉   5篇
儿科学   31篇
妇产科学   14篇
基础医学   171篇
口腔科学   18篇
临床医学   49篇
内科学   264篇
皮肤病学   8篇
神经病学   51篇
特种医学   12篇
外科学   252篇
综合类   2篇
预防医学   55篇
眼科学   67篇
药学   56篇
中国医学   1篇
肿瘤学   168篇
  2023年   12篇
  2022年   24篇
  2021年   48篇
  2020年   26篇
  2019年   43篇
  2018年   49篇
  2017年   42篇
  2016年   31篇
  2015年   26篇
  2014年   47篇
  2013年   46篇
  2012年   74篇
  2011年   85篇
  2010年   37篇
  2009年   28篇
  2008年   58篇
  2007年   53篇
  2006年   49篇
  2005年   57篇
  2004年   77篇
  2003年   50篇
  2002年   53篇
  2001年   23篇
  2000年   14篇
  1999年   18篇
  1998年   14篇
  1997年   9篇
  1996年   6篇
  1995年   4篇
  1994年   4篇
  1993年   3篇
  1992年   10篇
  1991年   7篇
  1990年   11篇
  1989年   21篇
  1988年   5篇
  1987年   8篇
  1986年   9篇
  1985年   7篇
  1984年   4篇
  1983年   5篇
  1975年   3篇
  1974年   2篇
  1972年   2篇
  1971年   1篇
  1970年   3篇
  1969年   3篇
  1968年   1篇
  1967年   1篇
  1966年   3篇
排序方式: 共有1224条查询结果,搜索用时 526 毫秒
101.
A 65-year-old woman presented with a 6-month history of abdominal pain and watery diarrhea. Type II enteropathy-associated T-cell lymphoma (EATL) was diagnosed based on the clinical presentation and pathological examination of the tumor. The patient received combination chemotherapy but did not achieve remission. Subsequently, high-dose therapy (HDT) and autologous stem cell transplantation (ASCT) were performed. After these therapies, she achieved complete remission, which has been sustained for 18 months. Although the role of HDT-ASCT for EATL is still controversial, the clinical course of this patient suggests that ASCT can improve the prognosis in some patients with EATL.  相似文献   
102.
103.
We studied single-neuron activity in the monkey dorsolateral prefrontal cortex during a saccade task, in which correct responses were rewarded after a delay of 0.5 or 1.5 s in one trial-block, and after 1.5 or 3-s delay in the other trial-block. Activity of some neurons depended on the relative length of the delays (longer or shorter) within each block, and activity for the 1.5-s trials was significantly different between the blocks. Activity of another group of neurons reflected the absolute length of delay: hence, the activity in the 1.5-s trials did not differ between the blocks. These results indicate that both relative and absolute time of future reward is represented in subsets of neurons in the dorsolateral prefrontal cortex.  相似文献   
104.
BACKGROUND/AIMS: Liver resection for hepatocellular carcinoma in patients with cirrhosis carries risk of major hemorrhage and sometimes requires blood transfusion. We investigated risk factors for massive blood loss during liver resection and indications for storing blood for autologous intraoperative transfusion. METHODOLOGY: We analyzed clinical records of 100 patients with cirrhosis who underwent liver resection for hepatocellular carcinoma. Autologous blood was stored preoperatively for 19 patients. RESULTS: Intraoperative blood loss ranged from 5 to 3000 mL (mean, 640). Liver resection was performed without transfusion in 67 patients and with autologous blood storage in 17 patients not receiving homologous blood. In the other 16 patients, homologous blood was transfused. Univariate analysis identified youth, large tumors (> 4cm), major hepatectomy, portal tumor involvement, hepatic vein involvement, and prolonged operation time as risk factors for massive blood loss; multivariate analysis identified portal involvement and hepatic vein involvement as independent risk factors. Blood loss exceeded 1000 mL in the 4 transfused group B patients and 3 of the 4 patients had hepatic vein involvement. CONCLUSIONS: Portal involvement and hepatic vein involvement were risk factors for massive blood loss during liver resection for hepatocellular carcinoma in patients with cirrhosis. Autologous blood storage is indicated in patients with such risk factors.  相似文献   
105.
OBJECTIVE: To develop a combined barrier method and drug delivery system ("hybrid system") for preventing postoperative peritoneal adhesions, which could combine the biocompatibility and ease of application of in situ cross-linkable hydrogels with the controlled release features of polymeric nanoparticles. METHODS: Poly(lactic-co-glycolic acid) nanoparticles were dispersed in aldehyde- and hydrazide-modified hyaluronic acids (HA), then combined via a double-barreled syringe. The material was subjected to mechanical testing and was assayed for in vitro cytotoxicity to murine mesothelial cells. Subsequently, it was tested for biocompatibility by intraperitoneal injection in mice. The hybrid's effectiveness in preventing postsurgical adhesions was assessed using a rabbit sidewall defect-cecum abrasion model, where it was applied to both injured surfaces. RESULTS: The in situ hybrid gel system formed a flexible and durable hydrogel in less than 10 seconds. It had low in vitro cytotoxicity. In the mouse, the cross-linked HA maintained the polymeric nanoparticles in the peritoneum for 1 week, which we had previously shown would have cleared in less than 2 days, and no animals developed adhesions. Notably, the hybrid gel, even in the absence of encapsulated drug, was highly effective in preventing peritoneal adhesions in the rabbit model employed. Animals treated with the hybrid (n = 8) had no adhesions in 62.5% of cases, and none had adhesions that could only be separated by sharp dissection. In contrast, only 4.2% of untreated animals (n = 24) had no adhesions, and 58.3% developed adhesions requiring sharp dissection. CONCLUSIONS: The hybrid cross-linked HA-nanoparticle system described here appears to be a biocompatible and highly effective adhesion barrier, which could also deliver antiadhesion drugs.  相似文献   
106.
107.
Some class I antiarrhythmic drugs induce a sporadic hypoglycemia by producing insulin secretion via inhibition of ATP-sensitive K(+) (K(ATP)) channels of pancreatic β-cells. It remains undetermined whether amiodarone produces insulin secretion by inhibiting K(ATP) channels. In this study, effects of amiodarone on K(ATP) channels, L-type Ca(2+) channel, membrane potential, and insulin secretion were examined and compared with those of quinidine in a β-cell line (MIN6). Amiodarone as well as quinidine inhibited the openings of the K(ATP) channel in a concentration-dependent manner without affecting its unitary amplitude in inside-out membrane patches of single MIN6 cells, and the IC(50) values were 0.24 and 4.9 μM, respectively. The L-type Ca(2+) current was also inhibited by amiodarone as well as quinidine in a concentration-dependent manner. Although glibenclamide (0.1 μM) or quinidine (10 μM) significantly potentiated the insulin secretion from MIN6 cells, amiodarone (1-30 μM) failed to increase insulin secretion. Amiodarone (30 μM) and nifedipine (10 μM) significantly inhibited the increase in insulin secretion produced by 0.1 μM glibenclamide. Amiodarone (30 μM) produced a gradual decrease of the membrane potential, but did not produce repetitive electrical activity in MIN6 cells. Glibenclamide (1 μM) produced a slow depolarization, followed by spiking activity which was inhibited by 30 μM amiodarone. Thus, amiodarone is unlikely to produce hypoglycemia in spite of potent inhibitory action on K(ATP) channels in insulin-secreting cells, possibly due to its Ca(2+) channel-blocking action.  相似文献   
108.
Atypical teratoid/rhabdoid tumor (AT/RT) is a malignant tumor that mostly occurs in early childhood and has poor prognosis despite aggressive therapy. Adult cases are rare and, as far as we are aware, only 30 cases have been reported to date. Here we present the case of a 27-year-old female with left parietal AT/RT with the chief complaint of numbness of the right superior limb. First, the tumor was surgically removed and the diagnosis was grade II glioma. With additional radiotherapy, the clinical course after surgery was favorable. After 6 years, she had an operation for recurrence and the diagnosis was grade III glioma. Temozolomide was prescribed, and a disease-free period of 2 years followed. Surgery was performed for a third time for second recurrence with histology of diffuse growth of rhabdoid cells. Immunohistochemistry was partially positive for vimentin and epithelial membrane antigen. Ki-67 labeling index was extremely high and tumor cells showed no staining of INI1 suggestive of diagnosis of AT/RT. We re-evaluated past specimens and none had immunoreactivity of INI1. Ki-67 labeling index and O-6 methylguanine DNA methyltransferase (MGMT) staining were also re-examined and both increased gradually. She is still alive without recurrence for more than 1 year. As far as we are aware, this is the second longest survival of an adult with AT/RT.  相似文献   
109.

Background  

In order to analyze the clinical activity and cost-effectiveness of granulocyte colony-stimulating factors (G-CSF), the prophylactic usage of G-CSF in patients treated with a single chemotherapy regimen during early courses was prospectively evaluated.  相似文献   
110.
Ras is a guanine nucleotide-binding protein that plays a major role in regulating the proliferation of T cells. To investigate the mechanism of the Ras/mitogen-activated protein kinase pathway, one of the downstream signal-transduction pathways of T-cell receptors, in the response to alloantigen, we performed full-thickness skin grafting in the major histocompatibility complex (MHC) incompatible strain BALB/c (H-2Kd) (donor) and T-cell-specific H-Ras dominant-negative (dnRas) transgenic (tg) C57BL/6 (H-2Kb) (recipient) male mice. In vitro and in vivo dnRas tg mouse T-cell proliferation and cytotoxic T lymphocyte (CTL) activity assay were also performed. The median graft survival time in control B6/wild type (wt) mouse allografts was seven days. Conversely, the dnRas tg mouse group exhibited a significant (p<0.01) prolongation of graft survival to 15 days. However, all grafts were eventually rejected after one month. Mixed lymphocyte reaction and popliteal lymph node assay revealed that T-cell proliferation was decreased in response to alloantigen, but CTL activity was not changed in the dnRas tg mice. These results suggested that Ras is essential for peripheral T lymphocytes to respond to allo-MHC antigens, and Ras may be a molecular target for controlling transplant rejection.  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