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   580篇
  免费   115篇
  国内免费   7篇
耳鼻咽喉   1篇
儿科学   19篇
妇产科学   5篇
基础医学   118篇
口腔科学   3篇
临床医学   85篇
内科学   79篇
皮肤病学   13篇
神经病学   11篇
特种医学   123篇
外科学   26篇
综合类   36篇
预防医学   29篇
眼科学   1篇
药学   14篇
中国医学   2篇
肿瘤学   137篇
  2024年   2篇
  2023年   2篇
  2022年   7篇
  2021年   12篇
  2020年   8篇
  2019年   10篇
  2018年   26篇
  2017年   17篇
  2016年   23篇
  2015年   14篇
  2014年   25篇
  2013年   30篇
  2012年   19篇
  2011年   23篇
  2010年   21篇
  2009年   29篇
  2008年   19篇
  2007年   26篇
  2006年   13篇
  2005年   14篇
  2004年   32篇
  2003年   33篇
  2002年   34篇
  2001年   35篇
  2000年   18篇
  1999年   21篇
  1998年   34篇
  1997年   15篇
  1996年   14篇
  1995年   12篇
  1994年   15篇
  1993年   18篇
  1992年   4篇
  1991年   3篇
  1990年   3篇
  1989年   10篇
  1988年   8篇
  1987年   5篇
  1986年   8篇
  1985年   5篇
  1984年   4篇
  1983年   5篇
  1982年   6篇
  1981年   2篇
  1980年   4篇
  1979年   2篇
  1978年   5篇
  1977年   2篇
  1975年   3篇
  1974年   1篇
排序方式: 共有702条查询结果,搜索用时 546 毫秒
41.
原发性颅内恶性淋巴瘤的CT诊断郭凡樊长姝北京铁路总医院CT室100038提要对6例经手术病理证实的原发性颅内恶性淋巴瘤的CT表现进行分析后,认为对发生在中线区表现为均匀高密度,边缘清楚具有分叶征象的病灶,可作为CT的表现的特点。在放、化疗过程中出现肿...  相似文献   
42.
Moraxella catarrhalis rarely causes severe infections or bacteraemia in healthy subjects. In the literature only four cases of clinical sepsis with M. catarrhalis have been described, mostly in immunocompromised patients. We describe a case of a 34-year-old patient with Kugelberg-Welander disease and low body weight (28 kg) who developed clinical sepsis due to M. catarrhalis bacteraemia. A review of the literature is given.  相似文献   
43.
Increased expression of CD38 on CD8(+) T cells is associated with activation of the immune system, progression of HIV disease, and death in adults. The prognostic significance of these cells in HIV-infected children, where the picture is complicated by age-related differences in CD38 expression, remains controversial. Measuring the unimodal expression of CD38 on CD8(+) T cells in adults and children by flow cytometry is best accomplished by quantitating the antigen on the cell surface. To our knowledge, this technique has not previously been reported in a pediatric population. Vertically HIV-infected children were age matched for mild (n = 26) and severe (n = 23) clinical disease. Eleven age-matched HIV-negative controls were included for comparison. Quantitation of CD38 on CD8(+) T cells was performed at baseline and 1 y later. The ages of the children in the three clinical groups did not differ significantly (p = 0.6004). HIV-infected children had significantly increased CD38 measurements in comparison with the HIV-negative controls (p = 0.0131), and the severe disease group tended to have higher measurements than the mild disease group. Increased CD38(+)CD8(+) T cells were significant predictors of death within the first year (p = 0.043). These findings support the view that increased CD38 expression on CD8(+) T cells has the same prognostic significance in pediatric as in adult HIV disease.  相似文献   
44.
45.
The arterial blood lactate [La] response to exercise increases in acute hypoxia, but returns to near the normoxic (sea level, SL) response after 2 to 5 weeks of altitude acclimatization. Recently, it has been suggested that this gradual return to the SL response in [La], known as the lactate paradox (LP), unexpectedly disappears after 8 to 9 weeks at altitude. We tested this idea by recording the [La] response to exercise every 2 weeks over 8 weeks at altitude. Five normal, fit SL-residents were studied at SL and 3,800 m (Pbar = 485 torr) in both normoxia (PIO2 = 150 torr) and hypoxia (PIO2 = 91 torr approximately air at 3,800 m). Arterial [La] and blood gas values were determined at rest and during cycle exercise at the same absolute workloads (0, 25, 50, 75, 90, and 100% of initial SL-VO2Max) and exercise duration (4, 4, 4, 2, 1.5, and 0.75 min, respectively) at each time point. [La] curves were elevated in acute hypoxia at SL (p < 0.01) and at 3,800 m fell progressively toward the SL-normoxic curve (p < 0.01). On the same days, [La] responses in acute normoxia showed essentially no changes over time and were similar to initial SL normoxic responses. We also measured arterial catecholamine levels at each load and found a close relationship to [La] over time, supporting a role for adrenergic influence on [La]. In summary, extending the time at this altitude to 8 weeks produced no evidence for reversal of the LP, consistent with prior data obtained over shorter periods of altitude residence.  相似文献   
46.
47.
Expression of the chemokine receptors CXCR4 and CCR5 was monitored using EDTA-anticoagulated whole blood held for different time periods prior to fluorescent-antibody staining. When left overnight CXCR4 expression on leukocytes was substantially increased, whereas CCR5 expression was reduced. The results were similar when heparin and acid-citrate-dextrose were used as anticoagulants.  相似文献   
48.
49.

BACKGROUND:

The FocalPoint Slide Profiler is an automated cervical cytology screening system that is approved for primary screening. It identifies up to 25% of slides as requiring No Further Review. However, few studies have evaluated FocalPoint performance with glandular abnormalities.

METHODS:

Sixty‐six SurePath Papanicolaou (Pap) tests with a diagnosis of atypical glandular cells were identified. A total of 172 Pap tests with a diagnosis of “endometrial cells present” were included as controls. Follow‐up histology was abnormal if diagnosed as high‐grade squamous intraepithelial lesions, adenocarcinoma in situ, carcinoma, or complex endometrial hyperplasia. The FocalPoint software ranked each case into 1 of 7 categories: quintiles 1 (high risk) through 5 (low risk), No Further Review, and Process Review.

RESULTS:

A total of 215 slides were qualified for review; 38 (57.6%) atypical glandular cells cases were abnormal on follow‐up biopsy, and 27 (71.1%) atypical glandular cells with abnormal follow‐up qualified for review; no cases were classified No Further Review, and 9 (33%) were ranked in quintile 1. Twenty‐three (82.1%) atypical glandular cells with benign follow‐up were qualified for review; 3 (11%) cases were classified No Further Review, and 4 (17%) were ranked in quintile 1. There was a statistically significant difference between the ranking of benign atypical glandular cells cases, abnormal atypical glandular cells cases, and control cases (P = .03). However, when collapsed into No Further Review versus all other quintiles, the differences were not significant (P = .20).

CONCLUSIONS:

The FocalPoint Slide Profiler did not classify glandular lesions with abnormal follow‐up in the No Further Review category. However, these cases were not preferentially ranked in quintile 1. FocalPoint‐screened slides need to be carefully reviewed for glandular abnormalities, regardless of the quintile ranking. Cancer (Cancer Cytopathol) 2010. © 2010 American Cancer Society.  相似文献   
50.
Modern surgical teaching is evolving at speed. The environment in which we learn and teach is subject to a number of extrinsic pressures. These are influencing ways in which medical students and trainees learn and are taught the discipline of surgery. As a surgical educator it is useful to understand the reasons for these changes and to acquire the skills necessary to provide effective teaching. This short article looks at reasons why one would wish to develop surgical teaching skills, covers basic principles associated with delivery of effective teaching sessions and briefly reviews other avenues that may enhance teaching practice.  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