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   165篇
  免费   5篇
基础医学   12篇
口腔科学   1篇
临床医学   3篇
内科学   29篇
皮肤病学   1篇
神经病学   3篇
特种医学   21篇
外科学   5篇
预防医学   4篇
眼科学   2篇
药学   6篇
肿瘤学   83篇
  2023年   2篇
  2022年   1篇
  2021年   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   2篇
  2015年   2篇
  2014年   4篇
  2013年   3篇
  2012年   6篇
  2011年   3篇
  2010年   5篇
  2009年   5篇
  2008年   10篇
  2007年   7篇
  2006年   4篇
  2005年   9篇
  2004年   8篇
  2003年   9篇
  2002年   8篇
  2001年   1篇
  2000年   7篇
  1999年   4篇
  1998年   5篇
  1997年   3篇
  1996年   2篇
  1995年   3篇
  1994年   3篇
  1993年   1篇
  1992年   8篇
  1991年   4篇
  1990年   4篇
  1989年   5篇
  1988年   4篇
  1987年   5篇
  1985年   5篇
  1984年   4篇
  1983年   2篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1979年   2篇
  1975年   1篇
  1970年   1篇
排序方式: 共有170条查询结果,搜索用时 15 毫秒
1.
PURPOSE: To compare the diagnostic accuracy of a digital film viewer (Smartlight 2000 Plus) versus a conventional view box for the identification of bone and joint disorders. MATERIAL AND METHODS: In order to evaluate the qualitative and quantitative differences of digital and conventional film viewers, 100 plain films of patients with bone and joint disorders taken in an emergency room January through May 1998 were reviewed utilizing both types of view boxes. Three radiologists expert of bone and joint disorders, independently compared the films, filled a form about the qualitative and quantitative analysis of the lesions depicted for each patient, and reported a few notes on the technical quality of the plain films in terms of exposure. The results were compared using the chi-square test (p < 0.005). RESULTS: Data analysis showed that the digital film viewer permitted a quicker reading of the film while decreasing the perception threshold for elementary lesions and ocular fatigue. All the radiographs read with the digital film viewer were considered technically adequate: the film quality was considered good in 10 cases and sufficient in 2. Two of the same radiographs read with the conventional view box were considered of good quality, nine were considered sufficient and one was considered insufficient due to overexposure. There were six cases of agreement and six of disagreement for the diagnosis: four were due to overexposure of the radiograph and two to better conspicuity provided by the digital film viewer. DISCUSSION: Correct image illumination is the first element a radiologist evaluates when reading a radiograph. A conventional view box may, when it is not properly maintained or when the radiograph is overexposed, decrease the radiologist's visual capacity. This increases the time required to read the radiograph and, therefore, physical and ocular fatigue, which in turn increases the risk of missing or misevaluating a lesion. A digital film viewer emits light with a variable intensity which is proportional to the optical density of the film. This increases the visual capacity of the radiologist and the lesion contrast, while reducing the factors which affect the radiograph reading. CONCLUSIONS: The use of a digital film viewer increased the visual capacity of the radiologist and eliminated the negative elements which complicated the radiograph reading and permitted the use of radiographs that would otherwise have been considered of poor quality due to overexposure. This, combined with the experience of the radiologist, decreased of the risk of missing or misevaluating a lesion.  相似文献   
2.
A 26-year-old man with AIDS-related complex (ARC) was treated with high-dose busulphan and cyclophosphamide, followed by allogeneic bone marrow transplantation. For 3 months before transplantation he received a combination of four drugs considered active against human immunodeficiency virus (HIV) to reduce the viral burden: zidovudine, acyloguanosine, fusidic acid and phenylidantoin. Although in reduced doses in coincidence with marrow engraftment, zidovudine therapy was scheduled after transplantation in order to protect donor cells from infection with HIV. Engraftment rapidly occurred and was documented by cytogenetic analyses. The post-transplant course was characterized by severe acute GvHD with irreversible hepatorenal failure. The patient died on day 48 after transplantation. Polymerase chain reaction analyses for detecting HIV DNA showed the persistence of positivity at day +30 and +45 after transplantation. Antibodies to specific HIV proteins evaluated with Western blot testing also persisted at days +21 and +35 after transplantation. Circulating immunocomplexes disappeared on day +31, and an increase in the CD4/CD8 ratio occurred. The short survival of the patient, affected by chronic hepatitis too, does not allow final conclusions about the role of BMT in HIV disease.  相似文献   
3.
Summary The anti-inflammatory agent diftalone was administered in the diet to male and female BALB/c mice at 300-, 600-, and 1200-ppm dose levels for 80 weeks, starting at 8 weeks of age. The animals were kept under observation until 126–128 weeks of age, when the experiment was terminated. Diftalone treatment at the highest dose was hepatotoxic and induced hepatocellular tumors in females, angiomas of the liver in males, and angiosarcomas of the liver in male and female mice. The 300- and 600-ppm dose levels were not carcinogenic. The compound was not mutagenic for Salmonella typhimurium.  相似文献   
4.
Acquired hemophilia is a life-threatening condition associated with a high mortality, occurring mainly in elderly patients. We report on a 92-year-old male, administered two courses of 90 microg kg(-1) of recombinant activated factor VII (rFVIIa) due to failure of human factor VIII (FVIII) therapy, without side effects nor evidence of thrombotic complications. Despite the bleeding being completely under control, the patient died on day 11 of acute respiratory failure due to pneumonia. This case confirms previous reports on the complexity and severity of this disorder, showing that rFVIIa is an effective and safe agent for achieving hemostasis even in elderly patients with a FVIII inhibitor.  相似文献   
5.
6.
Inositol-containing molecules are involved in important cellular functions, including signalling, membrane transport and secretion. Our interest is in lysophosphatidylinositol and the glycerophosphoinositols, which modulate cell proliferation and G-protein-dependent activities such as adenylyl cyclase and phospholipase A2. To investigate the role of glycerophosphoinositol (GroPIns) in the modulation of Ras-dependent pathways and its correlation to Ras transformation, we employed a novel liquid chromatography-tandem mass spectrometry technique to directly measure GroPIns in cell extracts. The cellular levels of GroPIns in selected parental and Ras-transformed cells, and in some carcinoma cells, ranged from 44 to 925 μM, with no consistent correlation to Ras transformation across all cell lines. Moreover, the derived cellular inositol concentrations revealed a wide range (150 μM to 100 mM) under standard [3H]-inositol-loading, suggesting a complex relationship between the inositol pool and the phosphoinositides and their derivatives. We have investigated these pools under specific loading conditions, designing a further HPLC analysis for GroPIns, combined with mass determinations of cellular phosphatidylinositol 4,5-bisphosphate. The data demonstrate that limiting inositol conditions identify a preferred pathway of inositol incorporation and retention into the polyphosphoinositides pool. Thus, under conditions of increased metabolic activity, such as receptor stimulation or cellular transformation, the polyphosphoinositide levels will be maintained at the expense of phosphatidylinositol and the turnover of its aqueous derivatives.  相似文献   
7.
Pulmonary adenoma susceptibility 1 (Pas1), the major locus affecting inherited predisposition to lung tumor development in mice, maps near the Kras2 gene. We previously reported a significant association between a KRAS2/RsaI polymorphism and the risk and prognosis of lung adenocarcinoma (ADCA) in the Italian population. In the present case-control study, we examined 269 lung ADCA patients, 121 squamous cell lung carcinoma patients, and 632 healthy individuals (general population controls) in the Japanese population with genetic markers spanning approximately 1200 kb in the KRAS2 region. Allele-specific oligonucleotide hybridization revealed the same KRAS2/RsaI polymorphism associated with risk and prognosis as in Italian lung ADCA patients; the polymorphism was significantly associated with clinical stage (P < 0.001) and survival rate (log rank = 0.0014), confirming the mapping of PAS1 and pointing to the role of this locus in human lung cancer.  相似文献   
8.
9.
Within the context of a large breast cancer screening program we conducted a retrospective survey to identify the personal, socioeconomic and behavioural characteristics associated with previous use of mammograms (Ma) and breast ultrasound examination (US). Contact was made with a sample of more than 10,000 resident women who were asked to complete three questionnaires. Achieving an answer rate of 86%, we collected data from 9,087 women, 50-70 years aged, coming from Abruzzo, a central Italian region. 61% of the participants performed Ma, while US was performed by 34%, and 67% of women attended at least one of those examinations. Multiple logistic regression results indicated that older age, low level of education, not performing diets and breast self examination were significant predictors of a lower use of both examinations. Women that were married, mothers, on menopause, with a family history of cancer, uterine fibroma, past users of oral contraceptives were more likely to having performed Ma, but not US. Age at menarche, BMI and smoking were found not to be significant in predicting attendance for both screening examinations, with the exception of ex-smokers for US. Our findings represent an important contribution to the development of the needed tailored interventions to increase breast screening participation.  相似文献   
10.

Background  

MFSD2A (major facilitator superfamily domain containing 2) gene maps on chromosome 1p34 within a linkage disequilibrium block containing genetic elements associated with progression of lung cancer.  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