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   7477篇
  免费   668篇
  国内免费   132篇
耳鼻咽喉   80篇
儿科学   500篇
妇产科学   185篇
基础医学   1368篇
口腔科学   101篇
临床医学   490篇
内科学   499篇
皮肤病学   260篇
神经病学   103篇
特种医学   298篇
外国民族医学   9篇
外科学   1197篇
综合类   594篇
预防医学   73篇
眼科学   50篇
药学   244篇
  2篇
中国医学   51篇
肿瘤学   2173篇
  2024年   11篇
  2023年   141篇
  2022年   159篇
  2021年   306篇
  2020年   297篇
  2019年   284篇
  2018年   268篇
  2017年   241篇
  2016年   281篇
  2015年   317篇
  2014年   459篇
  2013年   522篇
  2012年   331篇
  2011年   373篇
  2010年   312篇
  2009年   321篇
  2008年   341篇
  2007年   334篇
  2006年   327篇
  2005年   261篇
  2004年   273篇
  2003年   183篇
  2002年   161篇
  2001年   182篇
  2000年   140篇
  1999年   138篇
  1998年   119篇
  1997年   150篇
  1996年   88篇
  1995年   85篇
  1994年   93篇
  1993年   79篇
  1992年   65篇
  1991年   68篇
  1990年   50篇
  1989年   64篇
  1988年   39篇
  1987年   34篇
  1986年   52篇
  1985年   58篇
  1984年   53篇
  1983年   31篇
  1982年   43篇
  1981年   34篇
  1980年   27篇
  1979年   32篇
  1978年   20篇
  1977年   15篇
  1976年   10篇
  1975年   3篇
排序方式: 共有8277条查询结果,搜索用时 15 毫秒
1.
AimLung metastases are a negative prognostic factor in Ewing sarcoma, however, the incidence and significance of sub-centimetre pulmonary nodules at diagnosis is unclear. The aims of this study were to (1): determine the incidence of indeterminate pulmonary nodules (IPNs) in patients diagnosed with Ewing sarcoma (2); establish the impact of IPNs on overall and metastasis-free survival and (3) identify patient, oncological and radiological factors that correlate with poorer prognosis in patients that present with IPNs on their staging chest CT.Materials & methodsBetween 2008 and 2016, 173 patients with a first presentation of Ewing sarcoma of bone were retrospectively identified from an institutional database. Staging and follow-up chest CTs for all patients with IPN were reviewed by a senior radiologist. Clinical and radiologic course were examined to determine overall- and metastasis-free survival for IPN patients and to identify demographic, oncological or nodule-specific features that predict which IPN represent true lung metastases.ResultsFollowing radiologic re-review, IPN were found in 8.7% of patients. Overall survival for IPN patients was comparable to those with a normal staging chest CT (2-year overall survival of 73.3% [95% CI 43.6–89] and 89.4% [95% CI 81.6–94], respectively; p = 0.34) and was significantly better than for patients with clear metastases (46.0% [95% CI 31.9–59]; p < 0.0001). Similarly, there was no difference in metastasis-free survival between ‘No Metastases’ and ‘IPN’ patients (p = 0.16). Lung metastases developed in 40% of IPN patients at a median 9.6 months. Reduction of nodule size on neoadjuvant chemotherapy was associated with worse overall survival in IPN patients (p = 0.0084).ConclusionIPN are not uncommon in patients diagnosed with Ewing sarcoma. In this study, we were unable to detect a difference in overall- or metastasis-free survival between patients with IPN at diagnosis and patients with normal staging chest CTs.  相似文献   
2.
3.
4.
5.
6.
Classical Kaposi sarcoma (KS) usually appears on lower extremities accompanied or preceded by local lymphedema. However, the development in areas of chronic lymphedema of the arms following mastectomy, mimicking a Stewart–Treves syndrome, has rarely been described. We report an 81‐year‐old woman who developed multiple, erythematous to purple tumors, located on areas of post mastectomy lymphedema. Histopathological examination evidenced several dermal nodules formed by spindle‐shaped cells that delimitated slit‐like vascular spaces with some red cell extravasation. Immunohistochemically, the human herpesvirus type 8 (HHV‐8) latent nuclear antigen‐1 was detected in the nuclei of most tumoral cells confirming the diagnosis of KS. Lymphedema could promote the development of certain tumors by altering immunocompetence. Although angiosarcoma (AS) is the most frequent neoplasia arising in the setting of chronic lymphedema, other tumors such as benign lymphangiomatous papules (BLAP) or KS can also develop in lymphedematous limbs. It is important to establish the difference between AS and KS because their prognosis and treatment are very different. Identification by immunohistochemistry of HHV‐8 is useful for the distinction between KS and AS or BLAP.  相似文献   
7.
8.
The lung is the preferred site of metastasis from soft tissue sarcoma (STS). This systematic review aims to evaluate the outcomes of stereotactic body radiotherapy (SBRT) and metastasectomy (MTS) for the treatment of lung metastases from STS. A systematic review was carried out according to the PRISMA protocol. PubMed, Medline, EMBASE, Cochrane Library, Ovid and Web of Knowledge databases were searched for English-language articles to December 2018 using a predefined strategy. Retrieved studies were independently screened and rated for relevance. Data were extracted by two researchers. In total, there were 1306 patients with STS: 1104 underwent MTS and 202 had SBRT. The mean age ranged from 40 to 55.8 years in the MTS group and from 47.9 to 64 years in the SBRT group. The cumulative death rate was 72% (95% confidence interval 59–85%) in the MTS group and 56% (38–74%) in the SBRT group. The cumulative mean overall survival time was 46.7 months (36.4–57.0%) in the MTS group and 47.6 months (33.7–61.5%) in the SBRT group. The cumulative rate of patients alive with disease was 5% (2–9%) in the MTS group and 15% (6–36%) in the SBRT group. Finally, the cumulative rate of patients alive without disease in the two groups was 19% (9–29%) and 20% (10–50%), respectively. Our study showed that local treatment of pulmonary metastases from STS with SBRT, compared with surgery, was associated with a lower cumulative overall death rate and similar overall survival time and survival rates without disease. By contrast, SBRT was associated with a higher survival rate with disease than MTS. Large randomised trials are necessary to confirm these findings and to establish whether SBRT may be a reliable option for early stage disease.  相似文献   
9.
10.
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