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   583篇
  免费   12篇
  国内免费   36篇
儿科学   39篇
妇产科学   2篇
基础医学   58篇
口腔科学   8篇
临床医学   63篇
内科学   61篇
皮肤病学   8篇
神经病学   3篇
特种医学   195篇
外科学   56篇
综合类   19篇
预防医学   38篇
眼科学   10篇
药学   20篇
中国医学   1篇
肿瘤学   50篇
  2020年   2篇
  2018年   6篇
  2017年   4篇
  2016年   5篇
  2015年   11篇
  2014年   12篇
  2013年   10篇
  2012年   8篇
  2011年   11篇
  2010年   21篇
  2009年   37篇
  2008年   23篇
  2007年   34篇
  2006年   33篇
  2005年   29篇
  2004年   18篇
  2003年   12篇
  2002年   20篇
  2001年   31篇
  2000年   9篇
  1999年   25篇
  1998年   29篇
  1997年   34篇
  1996年   23篇
  1995年   11篇
  1994年   9篇
  1993年   12篇
  1992年   12篇
  1991年   5篇
  1990年   10篇
  1989年   21篇
  1988年   20篇
  1987年   10篇
  1986年   11篇
  1985年   7篇
  1984年   3篇
  1983年   4篇
  1982年   2篇
  1981年   7篇
  1979年   6篇
  1978年   2篇
  1977年   4篇
  1975年   3篇
  1972年   2篇
  1966年   1篇
  1931年   1篇
  1929年   2篇
  1927年   2篇
  1926年   7篇
  1925年   3篇
排序方式: 共有631条查询结果,搜索用时 15 毫秒
41.
Lasser  EC; Lang  JH; Lyon  SG; Hamblin  AE; Howard  MM 《Radiology》1981,140(1):11-15
An in vitro is described that attempts to detect patients with a potential for adverse systemic reactions to contrast material. This test involves measuring the rate of conversion of prekallikrein to kallikrein under certain standard conditions. In a preliminary retrospective study, the test could be used to identify such patients with a sensitivity of 88%, a specificity of 82%, and a predictive value of 79%.  相似文献   
42.
43.
44.
PURPOSE: To investigate the role of screening magnetic resonance (MR) imaging in the detection of synchronous contralateral breast cancer in patients with newly diagnosed breast cancer. MATERIALS AND METHODS: Between January 1999 and July 2001, 182 patients with newly diagnosed breast cancer (after either core or excisional biopsy with positive or close margins of resection) underwent bilateral contrast material-enhanced MR imaging at 1.5 T with a dedicated bilateral breast multicoil array. The contralateral breast was imaged for cancer screening. Family history of breast cancer, index cancer histology, breast density, and age at diagnosis of first breast cancer were assessed as potential risk factors for synchronous contralateral breast cancer. RESULTS: Fifteen patients (8.2%) had a suspicious enhancing lesion depicted in the contralateral breast. Seven patients (3.8%) had malignant results: ductal carcinoma in situ (DCIS) in four, invasive ductal carcinoma with DCIS in two, and invasive ductal carcinoma in one. Eight patients (4.4%) had benign results: fibrocystic changes in four, atypical ductal hyperplasia in two, atypical lobular hyperplasia and focal lobular carcinoma in situ in one, and ductal hyperplasia in one. Six patients with negative MR findings underwent prophylactic mastectomy; no malignancy was found. No significant differences were noted among patients with true-positive (n = 7), false-positive (n = 8), or negative (n = 167) MR findings with regard to family history of breast cancer (P <.27), index cancer histology (P <.19), breast density (P <.34), or age at diagnosis of first breast cancer (P <.10). CONCLUSION: The preliminary results demonstrate the feasibility of using MR imaging of the breast in a screening role, specifically to evaluate the contralateral breast in patients with newly diagnosed breast cancer to detect mammographically and clinically occult synchronous breast cancer.  相似文献   
45.
Chen C  Orel SG  Harris EE  Hwang WT  Solin LJ 《Cancer》2003,98(8):1596-1602
BACKGROUND: Mammography and physical examination are routine methods for the detection of ipsilateral local recurrence and contralateral breast carcinoma in patients initially undergoing breast conservation treatment. The current study reports the relation between the method of detection of the initial breast carcinoma and the method of detection of subsequent ipsilateral local recurrence and contralateral breast carcinoma. METHODS: A retrospective review was performed of the records of female patients with initial American Joint Committee on Cancer (AJCC) Stage I and II invasive breast carcinoma who developed ipsilateral local recurrence or contralateral breast carcinoma after breast conservation treatment. The method of detection of local recurrence in the ipsilateral breast and the method of detection of contralateral breast carcinoma were compared with the method of detection of the primary tumor. RESULTS: There were 125 ipsilateral breast local recurrences and 71 contralateral breast carcinoma cases detected. Of the 125 recurrences in the ipsilateral breast, 38% (48 recurrences) were detected by mammography only, 37% (46 recurrences) were detected by physical examination only, and 25% (31 recurrences) were detected by both methods. Of the 71 contralateral breast carcinoma cases, 53% (38 cases) were detected by mammography only, 23% (16 cases) were detected by physical examination only, and 24% (17 cases) were detected by both methods. When the primary tumors were detected by mammography only, 21% of the local recurrences (3 of 14 local recurrences) and 19% of the contralateral breast carcinoma cases (4 of 21 cases) were detected by physical examination only. When the primary tumors were detected by physical examination only, 24% of the local recurrences (14 of 58 local recurrences) and 42% of the contralateral breast carcinoma cases (8 of 19 cases) were detected by mammography only. When stratified by the interval between diagnosis of the primary tumor and ipsilateral local recurrence or contralateral breast carcinoma (< or = 5 years vs. > 5 years) or age of the patient at the time of ipsilateral breast recurrence or contralateral breast carcinoma (age < or = 49 years vs. age > or = 50 years), both breast examination and mammography were found to be important in the detection of locally recurrent tumor and contralateral breast carcinoma in each subgroup of the patients, regardless of the method of presentation of the primary tumor. CONCLUSIONS: Both mammography and physical examination were found to be significant in the detection of locally recurrent tumor in the ipsilateral breast and in the detection of contralateral breast carcinoma, regardless of the method of detection of the primary tumor.  相似文献   
46.
47.
A new WHO protocol for measuring tumor during clinical studies using upgraded methods of tumor diagnosis was released in 1994. The recommendations based on the examination of over 4,000 patients included measuring greatest diameter of tumor and evaluation of treatment effect by changes of a sum total of largest diameters. Therapeutic effect is established by a decrease in the sum by at least 30%, while tumor progression--by an increase by at least 20%. The GCP provide standards for planning, implementing, monitoring, auditing and documentation of clinical trials and submitting their findings. These standards guarantee the accuracy and reliability of data, patients' rights of health protection and anonymity of those taking part in trials. Today, these rules are binding for the European Community, Japan and the USA. All Russian medical establishments running clinical tests are to observe the rules.  相似文献   
48.
49.
50.
BACKGROUND: Sentinel lymph node (SLN) biopsy is being investigated as a staging procedure for breast carcinoma. The authors evaluated whether immunohistochemical (IHC) analysis improves the sensitivity of this procedure. METHODS: Forty-four women with breast carcinoma were recruited for SLN biopsy. Preoperative lymphoscintigraphy was followed by intraoperative localization using a handheld gamma probe and blue dye. After SLN identification, an immediate complete axillary lymph node dissection was performed in all patients. All lymph nodes were subjected to routine histology (hematoxylin and eosin [H&E]) and IHC using antibody to cytokeratins. RESULTS: The SLN was identified in 41 of 43 patients (95%). Successful SLN identification was independent of biopsy technique (open surgical [95%] vs. fine-needle aspiration/core needle biopsy [96%]). Twelve of 41 patients (29%) had evidence of lymph node metastasis in the SLN by routine histology. Of the twenty-nine patients with H&E negative SLN, 3 were found to have metastasis by IHC for a conversion rate of 10%. Fifteen of 41 patients (37%) had evidence of metastasis in SLN. All 26 patients with H&E and IHC negative SLN had negative nonsentinel lymph nodes by routine histology and IHC (100% negative predictive value). All patients with tumors < 2 cm and micrometastasis to the SLN had no additional lymph node disease, in contrast to patients with lesions > 2 cm or patients with macrometastasis to the SLN (P = 0.007). CONCLUSIONS: These results confirm that SLN biopsy is extremely accurate for patients with breast carcinoma, even after open surgical biopsy. IHC analysis or serial sectioning of SLN improves the sensitivity of this staging technique.  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