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   1742篇
  免费   55篇
  国内免费   10篇
耳鼻咽喉   2篇
儿科学   24篇
妇产科学   22篇
基础医学   206篇
口腔科学   18篇
临床医学   84篇
内科学   478篇
皮肤病学   4篇
神经病学   40篇
特种医学   116篇
外科学   208篇
综合类   7篇
预防医学   61篇
眼科学   99篇
药学   86篇
肿瘤学   352篇
  2023年   11篇
  2022年   15篇
  2021年   39篇
  2020年   25篇
  2019年   22篇
  2018年   25篇
  2017年   17篇
  2016年   34篇
  2015年   22篇
  2014年   42篇
  2013年   30篇
  2012年   70篇
  2011年   75篇
  2010年   47篇
  2009年   44篇
  2008年   61篇
  2007年   68篇
  2006年   83篇
  2005年   86篇
  2004年   80篇
  2003年   86篇
  2002年   74篇
  2001年   68篇
  2000年   61篇
  1999年   68篇
  1998年   20篇
  1997年   14篇
  1996年   18篇
  1995年   10篇
  1994年   15篇
  1993年   14篇
  1992年   38篇
  1991年   51篇
  1990年   57篇
  1989年   34篇
  1988年   30篇
  1987年   38篇
  1986年   35篇
  1985年   34篇
  1984年   22篇
  1983年   19篇
  1982年   12篇
  1979年   13篇
  1977年   11篇
  1976年   6篇
  1974年   9篇
  1973年   9篇
  1971年   7篇
  1969年   8篇
  1968年   7篇
排序方式: 共有1807条查询结果,搜索用时 0 毫秒
21.
Spectral imaging fluorescence microscopy   总被引:2,自引:0,他引:2  
The spectral resolution of fluorescence microscope images in living cells is achieved by using a confocal laser scanning microscope equipped with grating optics. This capability of temporal and spectral resolution is especially useful for detecting spectral changes of a fluorescent dye; for example, those associated with fluorescence resonance energy transfer (FRET). Using the spectral imaging fluorescence microscope system, it is also possible to resolve emitted signals from fluorescent dyes that have spectra largely overlapping with each other, such as fluorescein isothiocyanate (FITC) and green fluorescent protein (GFP).  相似文献   
22.
Urinary 1-microglobulin (U-A1M) was measured in healthy term infants on days 1, 4, 7, 14, 28, 90 and 180 of life. U-A1M was high until day 14 and declined thereafter. It was significantly correlated with urinary 2-microglobulin (U-B2M) throughout the study, but not with serum A1M on days 1 or 7. Similar to U-B2M, U-A1M in the clinically stable term infants with intrauterine growth retardation (n=4–7) was not elevated on days 1–7. In the sick infants who needed immediate resuscitatio at birth (n=4–8), U-A1M as well as U-B2M was high on days 1–7 and then decreased to normal levels, suggesting that U-A1M can be used as a sensitive marker of acute proximal tubular damage and its recovery. These observations indicate that U-A1M is a useful index of proximal tubular function in early infancy.  相似文献   
23.
The prolactin gene is expressed in the mouse kidney   总被引:1,自引:0,他引:1  
  相似文献   
24.
Summary A 43-year-old male smelter was admitted to a hospital on account of severe dyspnea about 2 days after exposure to brownish-yellow smoke produced by melting of copper scrap. On admission pronounced hypoxemia was revealed, and an oxygen-enriched gas was administered after intubation. Although inspired oxygen concentration was gradually increased, hypoxemia progressed and he died on day 11 in hospital.The principal autopsy finding was chiefly confined to the lungs. Both lungs were heavy (the left weighing 1,470 g; the right 1,710 g) and firm to the touch. Histologically, no normal alveoli were found throughout the entire lung. Some alveolar spaces were occupied by pneumocytes, others by organized exudate with fibrosis. Interstitial fibrosis was present. Patchy areas of inflammatory cell infiltrations as well as intra-alveolar hemorrhages were observed. On the basis of the above findings a diagnosis of diffuse alveolar damage was made.Based on the available evidence (presence of cadmium in the copper scrap, feature of the smoke, clinical signs with latent time, and high cadmium concentration of the lung), the diffuse alveolar damage was considered to have been caused by inhaled cadmium. The pulmonary change of the present case was more advanced in pathologic stage in comparison with those reported in the literature.  相似文献   
25.
The outcome following intra-operative radiation therapy in the treatment of osteosarcoma in the extremity in 33 patients was evaluated for oncological and functional results. Local recurrence occurred in seven cases, six of which were in a non-irradiated region, indicating inappropriate planning of the radiation field. Twenty-one patients underwent either prosthetic replacement (14) or amputation (7). Irradiated tumours were left in situ in the remaining 12 patients. In this latter group no degenerative joint changes were observed radiologically. Twenty-six patients experienced local complications, of which fracture of the irradiated bone was the most significant. Associated intramedullary nailing showed encouraging results in preventing fracture. Although IORT is effective for the local control of osteosarcoma in extremities, critical patient selection and improvements of treatment protocol are required in order to obtain a satisfactory outcome.  相似文献   
26.
Sepsis is often associated with a downward spiral through a spectrum of systemic inflammatory response syndrome (SIRS) culminating in organ failure and death. Here we present a 3-year-old girl with Hemophilus influenzae septic meningitis who developed SIRS and acute renal failure. In the initial stage, the patient showed uremia, cytopenia, disseminated intravascular coagulation, elevation of tissue enzyme and ferritin values, hemophagocytosis and overproduction of nitric oxide. The serum cytokine profile revealed increased levels of soluble interleukin (IL)-2 receptor, IL-6, IL-10 and tumor necrosis factor alpha. The patient responded positively to early and intensive interventions including antibiotics, repeated exchange transfusions, dexamethasone and high-dose gamma-globulin. The above laboratory abnormalities almost normalized with clinical improvement. We consider that SIRS was probably responsible for the sequence of events resulting in renal failure in this case, and suggest that renal failure should be included among the serious complications of SIRS associated with Hemophilus influenzae septic meningitis.  相似文献   
27.
The effect of graft-versus-host disease (GVHD) on relapse incidence and survival has been analyzed in several studies, but previous studies included heterogeneous patients. Therefore, we analyzed the data of 2114 patients who received unmanipulated bone marrow graft from an HLA-identical sibling donor with a GVHD prophylaxis using cyclosporin A and methotrexate. Among the 1843 patients who survived without relapse at 60 days after transplantation, 435 (24%) developed grade II-IV acute GVHD. Among the 1566 patients who survived without relapse at 150 days after transplantation, 705 (47%) developed chronic GVHD. The incidence of relapse was significantly lower in patients who developed acute or chronic GVHD, but disease-free survival (DFS) was significantly inferior in patients who developed acute GVHD. A benefit of 'mild' GVHD was only seen in high-risk patients who developed grade I acute GVHD. The strongest association between GVHD and a decreased incidence of relapse was observed in patients with standard-risk acute myelogenous leukemia/myelodysplastic syndrome. In conclusion, the therapeutic window between decreased relapse and increased transplant-related mortality due to the development of GVHD appeared to be very narrow.  相似文献   
28.
We report a case of intra-articular fracture of the knee joint showing three layers within lipohemarthrosis. Sagittal ultrasonography showed three layers (double fluid-fluid level): a superior hyperechoic layer of fat, an intermediate anechoic layer of serum, and an inferior hypoechoic layer of red blood cells. Horizontal computed tomography imaging demonstrated the same three layers. This is the first case of lipohemarthrosis in which three layers of joint effusion were confirmed by both ultrasonography and computed tomography.  相似文献   
29.
30.
Enzootic bovine leukosis (EBL) is a disease caused by bovine leukemia virus (BLV); only a small percentage of BLV-infected cattle develop EBL and present with B-cell lymphosarcoma. There is no vaccine against BLV, treatment for EBL, or method for predicting the possibility of EBL onset, thus making EBL control difficult. Herein, to explore biomarkers for EBL in milk, we examined the mRNA profiles of small extracellular vesicles (sEVs) in milk from four BLV-uninfected and four EBL cattle by microarray analysis. It was revealed that 14 mRNAs were encapsulated in significantly higher quantities, and these mRNAs were therefore selected as biomarker candidates. Primers for these mRNAs were designed, and nine primer sets were available for quantitative real-time PCR. Nine mRNAs were evaluated for their availability as biomarkers for EBL using sEVs from newly-collected milk of 7 uninfected and 10 EBL cattle. The quantities of eight mRNAs (TMEM156, SRGN, CXCL8, DEFB4A, FABP5, LAPTM5, LGALS1, and VIM) were significantly higher in milk sEVs of EBL cattle than in those of uninfected cattle. Therefore, our findings indicate that these eight mRNAs in milk sEVs can be used as potential EBL biomarkers with combination use, although single mRNA use is not enough. Consequently, cattle at risk of EBL onset can be identified by monitoring the fluctuation in quantities of these mRNAs in milk before they develop EBL.  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