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   701篇
  免费   117篇
  国内免费   7篇
耳鼻咽喉   4篇
儿科学   26篇
妇产科学   10篇
基础医学   94篇
口腔科学   3篇
临床医学   114篇
内科学   105篇
皮肤病学   14篇
神经病学   32篇
特种医学   131篇
外科学   37篇
综合类   38篇
预防医学   48篇
眼科学   3篇
药学   23篇
中国医学   2篇
肿瘤学   141篇
  2022年   8篇
  2021年   13篇
  2020年   11篇
  2019年   14篇
  2018年   31篇
  2017年   18篇
  2016年   31篇
  2015年   18篇
  2014年   32篇
  2013年   39篇
  2012年   29篇
  2011年   28篇
  2010年   26篇
  2009年   27篇
  2008年   25篇
  2007年   19篇
  2006年   18篇
  2005年   24篇
  2004年   33篇
  2003年   32篇
  2002年   35篇
  2001年   29篇
  2000年   19篇
  1999年   20篇
  1998年   31篇
  1997年   15篇
  1996年   14篇
  1995年   12篇
  1994年   16篇
  1993年   18篇
  1992年   7篇
  1991年   3篇
  1990年   4篇
  1989年   10篇
  1988年   9篇
  1987年   6篇
  1986年   13篇
  1985年   4篇
  1984年   9篇
  1983年   7篇
  1982年   9篇
  1981年   4篇
  1980年   5篇
  1979年   10篇
  1978年   11篇
  1977年   5篇
  1975年   6篇
  1974年   2篇
  1973年   3篇
  1968年   3篇
排序方式: 共有825条查询结果,搜索用时 218 毫秒
31.
目的:评价螺旋CT在诊断肺动脉栓塞中的作用。方法:16例肺动脉栓塞患者行螺旋CT肺动脉造影 (SCTA)检查,层厚3mm,扫描时间0.8s,对比剂注射速度3.5ml/s,总量100ml,扫描延迟时间15s。结果:16例 共644支,其中134支肺动脉及分支显示了栓塞,占20.8%。228支肺段肺动脉中,有56支显示肺动脉栓塞,占分 析肺动脉支的24.5%。204支亚段肺动脉中37支显示肺动脉栓塞,占分析肺动脉支15.4%。肺动脉栓塞的CT形 态:①直接征象为不同程度的肺动脉分支内充盈缺损。中心型充盈缺损17支,偏心型充盈缺损44支,附壁血栓型 34支,完全阻塞型39支。②间接征象胸膜下肺梗死灶,内乳动脉一侧增粗,肺纹理稀少,胸水,肺动脉高压。结论: 螺旋CT肺动脉造影是诊断肺动脉栓塞的快速、有效、无创伤的诊断方法。  相似文献   
32.
33.

BACKGROUND.

In addition to the reporting of atypical glandular cells (AGC) and adenocarcinoma (ADCA), the 2001 Bethesda System requires the reporting of benign‐appearing endometrial cells in women aged >40 years (BAEMC). In this study, the authors evaluated the contribution of each of these reporting categories to the sensitivity and specificity of a liquid‐based Papanicolaou test for endometrial carcinoma or hyperplasia.

METHODS.

Over the 3‐year study period, in the setting of a large, multihospital health care system, the authors analyzed the results from liquid‐based Papanicolaou tests that were performed within the 6 months that preceded a histologic diagnosis of endometrial carcinoma or hyperplasia and that were reported according to the 2001 Bethesda System.

RESULTS.

Two hundred seventy‐two women had a histologic diagnosis of endometrial hyperplasia (n = 199) or malignancy (n = 73) within 6 months after a Papanicolaou test. In total, 188,594 Papanicolaou tests (91,385 from women aged >40 years) were interpreted during the study period and resulted in 3810 diagnoses of BAEMC, 326 diagnoses of AGC, and 30 diagnoses of ADCA. Only 28 of 73 women (38.4%) with endometrial carcinoma had cytologically AGC or ADCA reported on a previous Papanicolaou test. The reporting of BAEMC increased this sensitivity by only 5.5% (4 additional tests) but decreased the specificity of the Papanicolaou test for endometrial malignancy from 99.8% to 96%. For endometrial hyperplasias, the sensitivity of the Papanicolaou test was even lower (39 of 198 tests; 19.7%), but BAEMC represented the majority of endometrial‐type cells reported (36 of 39 tests).

CONCLUSIONS.

The reporting of BAEMC led to an only marginal increase in sensitivity that had to be weighed against the significant loss in specificity of the Papanicolaou test for endometrial neoplasia. Cancer (Cancer Cytopathol) 2007. © 2007 American Cancer Society.  相似文献   
34.
目的着重探讨45例缺血性肠病患者的病因、CT检查技术及其影像表现。资料与方法45例缺血性肠病均经螺旋CT扫描。26例经过手术证实,14例经过治疗痊愈,5例急性死亡。结果其中肠系膜动脉缺血24例,肝固有动脉缺血4例,肠系膜静脉缺血17例。结论严格掌握CT检查技术,根据CT影像表现并密切结合临床,对缺血性肠病患者可以作出确定诊断。  相似文献   
35.

BACKGROUND.

The ThinPrep Imaging System (TIS) has been approved by the U.S. Food and Drug Administration for use to decrease the number of false‐negative results in ThinPrep (TP) gynecologic specimens and increase cytotechnology productivity. Although the increased detection of squamous abnormalities using the TIS has been well documented, to the authors' knowledge, data regarding the impact of the TIS in the detection of glandular abnormalities is limited. The goal of the current study was to evaluate the effectiveness of the TIS in detecting glandular abnormalities in cervicovaginal specimens.

METHODS.

TIS evaluated TP tests with histologic confirmation of adenocarcinoma involving the gynecologic system were included in the current study. Two cytotechnologists independently reviewed the cases for the presence or absence of atypical glandular cells. Review results were correlated with initial cytologic and histologic diagnoses.

RESULTS.

A total of 124 cases met the criteria for inclusion in the current study. Seventy of these cases (56%) were found to contain atypical glandular cells on the TP slide. TIS was able to identify atypical cells in 97% of these cases (68 of 70 cases). Nine cases initially reported as benign were found to contain atypical glandular cells on secondary review. All but 1 of these cases contained atypical glandular cells detected by the TIS. The majority of these false‐negative cases (6 of 9 cases) derived from endometrial adenocarcinoma. No cytologic evidence of a glandular abnormality was found in the 54 remaining cases.

CONCLUSIONS.

The TIS was found to be effective in identifying atypical glandular cells in specimens containing malignant glandular cells, leading to a full review of the slide. Cancer (Cancer Cytopathol) 2008. © 2007 American Cancer Society.  相似文献   
36.
37.
Adenocarcinoma in situ (ACIS) of the uterine cervix is an increasingly recognized disease. Thirty-seven cases were reviewed to determine the effect of HPV, marital status, parity, smoking habit and age on the topography and behaviour of this lesion. Using a commercial probe, 25% of 28 lesions tested were positive for HPV 16/18. The presence of HPV and a history of smoking appeared to exert no significant influence upon the topography and behaviour of ACIS. Nulliparity and a history of never being married was associated with a significant reduction in the incidence of coexisting CIN lesions. Age less than 36 years was associated with a significant reduction in the proximal linear extent of ACIS. While hysterectomy is probably the definitive treatment for ACIS of the cervix, there is an important place for conservative management by conization alone. Patients younger than 36 years are most likely to be desirous of retained fertility and appear to have the lesions most amenable to conservative surgery.  相似文献   
38.
39.
The Significance of Mild Squamous Atypia on Cytology   总被引:2,自引:0,他引:2  
Summary: Between January, 1991 and February, 1993 inclusive, 396 Papanicolaou smears were reported to show Mild Squamous Atypia with or without Human Papilloma Virus (MSA ± HPV). All women with MSA ± HPV smears were routinely recalled for colposcopy. To determine the significance of MSA ± HPV on routine smear screening, the records of all patients were reviewed.
Three hundred and thirty-seven women (85.1%) attended the colposcopy clinic and are the subjects analyzed for this report. The remaining 59 (14.9%) failed to attend. Intraepithelial neoplasia was found in 61 patients (18.1%), of whom 27 (8.0%) had a high grade lesion (CIN 2 or 3 or GIN 2). No patient had invasive cancer of the cervix. Only 1 of the 45 pregnant women had a significant lesion.
It is concluded that all asymptomatic women with MSA ± HPV on cervical smear may be managed in accordance with the current NH and MRC recommendations (1) and have a repeat smear in 6 months and colposcopy if the abnormality persists at 12 months.  相似文献   
40.
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