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   3341篇
  免费   178篇
  国内免费   10篇
耳鼻咽喉   13篇
儿科学   72篇
妇产科学   87篇
基础医学   418篇
口腔科学   101篇
临床医学   196篇
内科学   780篇
皮肤病学   147篇
神经病学   307篇
特种医学   84篇
外科学   582篇
综合类   14篇
预防医学   90篇
眼科学   54篇
药学   227篇
中国医学   8篇
肿瘤学   349篇
  2022年   32篇
  2021年   61篇
  2020年   24篇
  2019年   32篇
  2018年   52篇
  2017年   32篇
  2016年   58篇
  2015年   56篇
  2014年   75篇
  2013年   88篇
  2012年   131篇
  2011年   144篇
  2010年   94篇
  2009年   90篇
  2008年   145篇
  2007年   177篇
  2006年   161篇
  2005年   176篇
  2004年   149篇
  2003年   204篇
  2002年   186篇
  2001年   127篇
  2000年   107篇
  1999年   100篇
  1998年   34篇
  1997年   38篇
  1996年   30篇
  1995年   26篇
  1994年   28篇
  1993年   35篇
  1992年   94篇
  1991年   89篇
  1990年   67篇
  1989年   61篇
  1988年   43篇
  1987年   52篇
  1986年   47篇
  1985年   55篇
  1984年   48篇
  1983年   40篇
  1982年   13篇
  1980年   16篇
  1979年   36篇
  1978年   14篇
  1977年   15篇
  1976年   14篇
  1972年   14篇
  1971年   23篇
  1970年   11篇
  1967年   13篇
排序方式: 共有3529条查询结果,搜索用时 15 毫秒
41.
We present the case of a 69-years-old man who was admitted to hospital with multiple myeloma. IgG-kappa type monoclonal protein was detected in the serum. When we separated the serum obtained from blood sample of the patient and the lid of the collecting tube was opened, the patient's serum became gelled immediately. When the lid of the collecting tube remained closed, the patient's serum did not become gelled even at 4 degrees C. Moreover, the gelled serum of the patient did not resolve at 56 degrees C. Taken together, these results indicated that gel formation of the patient's serum may not be due to cryoglobulin. It was found that the pH of the patient's serum elevated to pH 8.0 quickly after exposed to air. It was also found that the patient's serum, but not the sera of other IgG-kappa multiple myeloma patients, became gelled as soon as PBS of pH 8.0 was added. These results highly suggest that the patient's serum becomes gelled at pH 8.0. However, the isoelectric focusing of isolated precipitation in the patient showed fractions around the pH 8.5-8.7 zone, which was different from the pH at which the precipitation began to form. We think that this may be the first report of a multiple myeloma patient whose serum becomes gelled after exposed to air.  相似文献   
42.
43.
Neuropathology of Creutzfeldt-Jakob disease (GJD), particularly of the panencephalopathic type and its additional findings, was described. The panencephalopathic type of CJD was characterized by extensive degeneration of the cerebral white matter which is diffuse in the deep and circumscribed and spongy in the digital white matter. This white matter lesion could not be explained simply as secondary to cortical deterioration. Most cases of the panencephalopathic type disclosed Involvement of anatomically-interrelated systems in various combinations (inferior olivary nucleus-pontine nucleuscerebellar cortex, globus pallidus - subthalamus - substantia nigra, optic tract-lateral geniculate body - optic radiation, and primary thalamic degeneration). These associated findings which could be paralleled as those of combined multisystemic degenerations have been found not only in the panencephalopathic type but also in other subtypes of CJD including Japanese cases of spongiform encephalopathy with multiple kuru plaques. They cannot be considered as coincidental to CJD.  相似文献   
44.
In vitro antiviral activity of lactoferrin and ribavirin upon hantavirus   总被引:2,自引:0,他引:2  
Summary.  Bovine lactoferrin (LF) and ribavirin (Rbv) were tested as antiviral agents against Seoul type hantavirus (SR-11 strain) in vitro. Hantaviral foci number in Vero E6 cells infected with SR-11 was reduced with LF treatment by 5 days post infection to obtain a 50% effective dose (ED50) of 2500 μg/ml, while pretreatment with LF was highly efficacious having an ED50 of 39 μg/ml. Conversely, 1 h pretreatment with Rbv revealed no inhibition of viral focus formation but could significantly reduce the number of viral foci (ED50: 10 μg/ml) when used from the time of viral infection. One hour pre-treatment of the cell monolayer with LF and subsequent addition of Rbv revealed a synergistic anti-hantaviral effect against SR-11, <20 FFU/ml as compared to 105 foci/ml in the control. One hour treatment of SR-11 with LF prior to cell inoculation gave an ED50 of 312.5 μg/ml. Whereas, washing the LF-pretreated cell monolayer with PBS demonstrated minimal focus reduction, suggesting LF lightly adheres to cells. These results indicate that LF has anti-hantaviral activity in vitro and inhibition of virus adsorption to cells which play an important role in revealing the anti-hantaviral activity of LF. This paper reports for the first time the anti-hantaviral effect of LF. Received September 21, 1999 Accepted March 15, 2000  相似文献   
45.
46.
47.
The macrophage inhibition test was carried out using colostral macrophages obtained from PPD sensitive and measles and mycoplasma pneumoniae antigen insensitive woman. The macrophage migration was inhibited by PPD but neither by measles nor by mycoplasma pneumoniae antigen. Human colostral macrophages can be used as indicator cells in migration inhibition tests.  相似文献   
48.
49.
BackgroundAlthough the patients with muscle-invasive bladder cancer (MIBC) generally have poor prognosis, the utility of these biomarkers for the prediction of oncological outcomes in MIBC has not been completely explored. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, and angiogenesis. Thus, we aimed to evaluate the impact of serum ghrelin levels on survival in MIBC.MethodsIn this study, we reviewed the clinical and pathological records of 56 patients who were diagnosed with MIBC between November 2015 and November 2019 at Gifu and Hirosaki University Hospitals. We focused on 27 patients who had received chemotherapy and collected blood samples before and after chemotherapy. Blood samples were collected before chemotherapy and after completing two cycles of chemotherapy. Serum acyl (AG) and desacyl ghrelin (DG) were measured using AG and DG enzyme-linked immunosorbent assay kits (SCETI, Tokyo, Japan), respectively.ResultsThe 3-year overall and progression-free survival (PFS) rates were 82.9% and 68.3%, respectively. According to the AG level after chemotherapy, the 3-year PFS rates were 77.5% and 53.0% in patients with AG levels ≥1.34 and <1.34 pg/mL, respectively (P=0.038). With regard to DG levels after chemotherapy, the 3-year PFS rates were 90.9% and 43.3% in patients with DG levels <92.3 and ≥92.3 pg/mL, respectively (P=0.039). On multivariate analysis, serum AG levels were significantly associated with PFS.ConclusionsThis study suggested the usefulness of the ghrelin as a prognostic predictor of PFS in patients with MIBC.  相似文献   
50.
Technetium-99m labeled diethylenetriaminepentaacetic acid (DTPA)-galactosyl human serum albumin (GSA) has been used for hepatocellular functional evaluation. This study proposed new and simple parameters to overcome the limitations of conventional parameters, and they were applied to the clinical staging of chronic liver dysfunction. The study group consisted of 93 patients including 81 with liver dysfunction and 12 control patients. In addition to the two conventional parameters, namely, receptor index (LHL15 = liver count divided by the sum of liver and heart counts at 15 minutes) and clearance index (HH15 = heart count at 15 minutes divided by the heart count at 3 minutes), 6 new parameters for Tc-99m GSA uptake and clearance were generated. The conventional receptor index of LHL15 showed a large variation depending on the size of region of interest (ROI) over the heart. The LHL15 normalized by the ROI size (nLHL15) showed more stable data and a better separation of mild liver dysfunction. A hyperbolic relationship between the LHL15 and HH 15 changed to a linear relationship by using the nLHL15 index. The combination of the liver to heart average count ratio at 15 minutes (LH 15) and T-half (minute) of the heart count also could differentiate each stage well. In conclusion, the use of the ROI-area normalized nLHL is recommended instead of the conventional LHL15. The indices of LH15 and T-half could be alternatively used as practical parameters for clinical staging in liver function.  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