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   2043篇
  免费   184篇
  国内免费   17篇
耳鼻咽喉   35篇
儿科学   15篇
妇产科学   6篇
基础医学   476篇
口腔科学   44篇
临床医学   122篇
内科学   456篇
皮肤病学   18篇
神经病学   128篇
特种医学   46篇
外科学   382篇
综合类   4篇
预防医学   46篇
眼科学   11篇
药学   159篇
中国医学   5篇
肿瘤学   291篇
  2023年   11篇
  2022年   18篇
  2021年   50篇
  2020年   23篇
  2019年   27篇
  2018年   25篇
  2017年   29篇
  2016年   28篇
  2015年   34篇
  2014年   53篇
  2013年   58篇
  2012年   66篇
  2011年   87篇
  2010年   47篇
  2009年   36篇
  2008年   53篇
  2007年   95篇
  2006年   81篇
  2005年   81篇
  2004年   86篇
  2003年   87篇
  2002年   68篇
  2001年   76篇
  2000年   58篇
  1999年   65篇
  1998年   34篇
  1997年   39篇
  1996年   25篇
  1995年   21篇
  1994年   23篇
  1993年   16篇
  1992年   60篇
  1991年   61篇
  1990年   67篇
  1989年   58篇
  1988年   61篇
  1987年   71篇
  1986年   61篇
  1985年   51篇
  1984年   41篇
  1983年   40篇
  1982年   20篇
  1981年   16篇
  1980年   12篇
  1979年   29篇
  1978年   9篇
  1977年   16篇
  1969年   10篇
  1967年   7篇
  1966年   7篇
排序方式: 共有2244条查询结果,搜索用时 31 毫秒
61.
Lung cancer-specific cytotoxic T lymphocytes (CTL) were induced by repeated stimulations of regional lymph node lymphocytes (RLNL) in lung cancer patients with either autologous or HLA-A-locus-matched tumor cells. To investigate the effect of interleukin-12 (IL-12), IL-12 was added during the stimulation of RLNL from HLA A24 / adenocarcinoma patients with either autologous tumor cells or HLA A24-positive adenocarcinoma cells (PC-9) in combination with, or instead of interleukin-2 (IL-2), and then the cytotoxic activity, cytokine production and populations of the lymphocyte subsets were examined. The addition of IL-12, or the substitution of IL-2 by IL-12 was found to enhance the cytotoxic activity and the cytokine production (IFN-γ, GM-CSF) of the CTL as compared with IL-2 alone. The cytotoxic activity and cytokine production were both partially inhibited by anti-MHC-class I monoclonal antibody. The CTL thus induced by IL-12 had a higher proportion of CD3+/CD56+ cells than the CTL induced with IL-2 alone. The positively selected CD8+/CD56 lymphocytes showed PC-9-specific cytotoxic activity, because the population did not show any cytotoxicity to K562 or A549 (HLA-A26/A30). However, the CD3+/CD56+ lymphocytes were cytotoxic to both PC-9 and K562. In conclusion, IL-12 is considered to be a useful cytokine for both the induction of lung-cancer specific CTL and the augmentation of non-MHC-restricted cytotoxicity against tumor cells, and may be applicable for adoptive immunotherapy using CTL.  相似文献   
62.
Antitumor activity of interleukin-12 against murine bladder cancer   总被引:5,自引:0,他引:5  
PURPOSE: We investigated the antitumor activity of interleukin-12 (IL-12) against MBT-2, a murine bladder carcinoma, to clarify whether or not IL-12 is effective against urothelial tumors. MATERIALS AND METHODS: MBT-2, a murine carcinogen-induced, poorly differentiated transitional cell carcinoma of C3H/He origin, was used. Three or 10 days after the subcutaneous administration of MBT-2 cells, C3H/He mice were injected intraperitoneally with IL-12 five times per wk. for 2 wk. Tumor growth was measured twice weekly. Spleen cells from the C3H/He mice that had rejected MBT-2 after the IL-12 treatment were examined for MBT-2-specific cytolytic T lymphocytes (CTL) activity and cytokine production. RESULTS: Tumor growth and acceptance was obviously suppressed when C3H/He mice were treated with IL-12 from 3 days after the tumor inoculation. In the spleen cells from the C3H/He mice that had rejected MBT-2, MBT-2-specific CTL activity and secretion of IL-2 and interferon (IFN)-gamma were clearly detected. However, the established MBT-2 tumor cells were not rejected when C3H/He mice were given IL-12 from 10 days after the tumor inoculation, although the tumor growth was transiently suppressed during the IL-12 treatment. CONCLUSION: These data demonstrate that IL-12 is considerably effective against murine bladder cancer and suggest the clinical application of IL-12 against human bladder cancer.  相似文献   
63.
Background Fusobacterium nucleatum (F. nucleatum) is a gut microbe implicated in gastrointestinal tumorigenesis. Predicting the chemotherapeutic response is critical to developing personalised therapeutic strategies for oesophageal cancer patients. The present study investigated the relationship between F. nucleatum and chemotherapeutic resistance in oesophageal squamous cell carcinoma (ESCC).Methods We examined the relationship between F. nucleatum and chemotherapy response in 120 ESCC resected specimens and 30 pre-treatment biopsy specimens. In vitro studies using ESCC cell lines and co-culture assays further uncovered the mechanism underlying chemotherapeutic resistance.Results ESCC patients with F. nucleatum infection displayed lesser chemotherapeutic response. The infiltration and subsistence of F. nucleatum in the ESCC cells were observed by transmission electron microscopy and laser scanning confocal microscopy. We also observed that F. nucleatum modulates the endogenous LC3 and ATG7 expression, as well as autophagosome formation to induce chemoresistance against 5-FU, CDDP, and Docetaxel. ATG7 knockdown resulted in reversal of F. nucleatum-induced chemoresistance. In addition, immunohistochemical studies confirmed the correlation between F. nucleatum infection and ATG7 expression in 284 ESCC specimens.Conclusions F. nucleatum confers chemoresistance to ESCC cells by modulating autophagy. These findings suggest that targeting F. nucleatum, during chemotherapy, could result in variable therapeutic outcomes for ESCC patients.Subject terms: Tumour biomarkers, Oesophageal cancer  相似文献   
64.
We report a 54-year-old Japanese woman who developed liver tumors 102 months after hepatic resection for hepatocellular carcinoma (HCC) and percutaneous transluminal angioplasty (PTA) for membranous obstruction of the inferior vena cava (MOVC), which is one form of Budd-Chiari syndrome. In the present admission workup showed no evidence of co-infection with hepatitis B and C viruses. Dynamic computed tomography (CT) and magnetic resonance imaging showed an enhanced lesion, 1.5cm in diameter, in segment 3 of the liver, and no obstruction of the inferior vena cava after PTA. CT during both arterial portography and hepatic arteriography revealed another lesion, showing different hemodynamics, in segment 2. The patient therefore underwent hepatic resection, and the tumors were diagnosed histologically as HCC. The two tumors differed in their morphological features, one containing abundant fibrous stroma, whereas the other did not. The nontumorous liver tissue showed central zonal fibrosis, i.e., reversed lobulation, and partial expansion of nodule-like formations, indicating lack of progression since the situation seen at the initial hepatectomy. The presence of nontumorous liver tissue showing the above features suggests that, even after successful treatment for relief of congestion, patients who have had MOVC should be followed closely for as long as possible because of the risk of HCC recurrence. This is the first reported case of HCC recurrence after successful treatment of MOVC.  相似文献   
65.
66.
67.
68.
Cerebral rheumatoid vasculitis (CRV) is a rare, fatal, and diagnostically challenging disorder. We herein report an 81-year-old woman with a 4-year history of rheumatoid arthritis who presented with a fever, progressive disturbance of consciousness, high level of rheumatoid factor, and hypocomplementemia. The enhancement of the perforating branches in the left middle cerebral artery led us to suspect CRV. A brain biopsy could not be performed. After we intensified steroid therapy, the size of the cerebral lesions temporarily decreased. However, recurrence in the left frontal lobe occurred one month later, and the patient subsequently died. Early intensive treatments may be needed for CRV.  相似文献   
69.
To characterize rT3 5'-deiodinase (5'D) in rat skeletal muscle, the effects of altered thyroid status and PTU on rT3 5'D were studied. rT3 5'D activity was measured by incubating homogenates of rat skeletal muscle with [125]rT3, iodine labelled in the outer ring, in the presence of 20 mmol/l DL-dithiothreitol. This activity was observed to increase significantly 24 h after a single sc injection of T3 (75 micrograms/kg). The increase following the daily administration of this drug (15 or 75 micrograms/kg) for 3 and 14 days was dependent on the dose and number of previous days of injection. A significant decrease in activity was observed 2 weeks after thyroidectomy. The addition of 0.1 mmol/l 6-n-propyl-2-thiouracil (PTU) to the incubation medium in vitro caused a marked reduction in the activity in homogenates of skeletal muscle from hypothyroid, euthyroid and hyperthyroid rats. PTU, present at 0.05% in the drinking water for 2 weeks virtually abolished it. The properties of rT3 5'D in rat skeletal muscle thus appear to be essentially the same as those of type I enzyme with respect to response toward altered thyroid status and PTU.  相似文献   
70.
The clinical features of familial Creutzfeldt-Jakob disease with a codon 200 point mutation [fCJD (E200K)] are similar to those of sporadic CJD (sCJD). MRI diffusion-weighted imaging (MRI-DWI) has been reported to be useful for the early diagnosis of CJD. We describe a Japanese fCJD (E200K) case in which thalamic symptoms were the initial manifestations. On admission, electroencephalography (ECG) showed no periodic synchronous discharge (PSD), and MRI showed no abnormalities. However, single photon emission computed tomography (SPECT) using (99m)Tc-ethyl cysteinate dimer ((99m)Tc-ECD) revealed hypoperfusion in the right thalamus. We conclude that the thalamic form of CJD tends to show no high-intensity area (HIA) by MRI-DWI, and that SPECT may be more useful for visualizing the affected area responsible for the thalamic symptoms at an early stage.  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