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   419篇
  免费   23篇
  国内免费   1篇
耳鼻咽喉   20篇
儿科学   11篇
妇产科学   4篇
基础医学   26篇
口腔科学   16篇
临床医学   25篇
内科学   158篇
皮肤病学   1篇
神经病学   22篇
特种医学   22篇
外科学   52篇
综合类   2篇
预防医学   19篇
眼科学   7篇
药学   13篇
肿瘤学   45篇
  2024年   1篇
  2023年   3篇
  2022年   10篇
  2021年   17篇
  2020年   17篇
  2019年   12篇
  2018年   14篇
  2017年   9篇
  2016年   20篇
  2015年   9篇
  2014年   23篇
  2013年   22篇
  2012年   45篇
  2011年   43篇
  2010年   24篇
  2009年   30篇
  2008年   16篇
  2007年   27篇
  2006年   27篇
  2005年   12篇
  2004年   13篇
  2003年   15篇
  2002年   15篇
  2001年   5篇
  2000年   2篇
  1999年   2篇
  1997年   5篇
  1996年   2篇
  1995年   1篇
  1991年   1篇
  1989年   1篇
排序方式: 共有443条查询结果,搜索用时 31 毫秒
91.
Anaplastic ependymoma is associated with a higher incidence of tumor recurrence and its prognosis still remains unsatisfactory. Consolidated therapy for ependymoma includes surgery followed by focal radiotherapy when resection is incomplete. In the case of relapse treatment, options are limited especially for patients who have already received radiotherapy. We sought to establish the feasibility of administering low-dose oral etoposide (50 mg/m(2)/day for 21 days) in combination with the implantation of intracavitary carmustine (BCNU) wafers (Gliadel) at the gross total resection for achieving synergistic treatment in three children affected by recurrent anaplastic ependymoma. All patients had Karnofsky performance scale (KPS) scores >80%. The therapy was tolerated safely and well in all patients without any post-surgery complications. After BCNU wafer implantation, all patients achieved radiological and clinical stabilization for an average period of 3 months. Two patients relapsed after 4 months as shown in brain MRIs. The other patient went to progression two months after the Gliadel implantation. This multimodal approach was not effective for the treatment of refractory anaplastic ependymoma and further studies are required in order to define the role of the combination of multidrug systemic chemotherapy with BCNU wafer implantation in children with high-risk brain tumors.  相似文献   
92.

BACKGROUND:

In the attempt to characterize the genetic bases of recurrent head and neck squamous cell carcinoma (HNSCC) after radiotherapy (RT), the authors compared the molecular profiles of primary tumors and recurrences.

METHODS:

TP53 gene status and instability at 10 microsatellite markers were determined in pre‐RT lesions and corresponding local recurrences in a series of 16 HNSCCs.

RESULTS:

Eight (50%) HNSCCs showed both TP53 and microsatellite instability (MSI) status concordance in pre‐ and postirradiation biopsies; 3 (18.7%) showed discordance of both TP53 and MSI status; and finally 5 (31.2%) had discordance at only 1 genetic test. Accordingly, the authors interpreted as true recurrence the 8 concordant cases, and as true second primary malignancies the 3 discordant ones. In the remaining 5 cases with partial DNA correspondence, the exact nature of the new lesion only partially related to the original cancer is a matter of discussion. Patients showing the same mutations among pre‐ and post‐RT HNSCCs had a longer disease‐free interval (DFI) and better survival than those showing discordant genetic features (log‐rank test, P = .0045).

CONCLUSIONS:

Post‐RT recurrent HNSCCs are genetically heterogeneous. The genetic characterization of the recurrence, especially in those cases with a particularly short DFI showing partially discordant mutations, might have a useful clinical relevance in the restaging process. Cancer 2010. © 2010 American Cancer Society.  相似文献   
93.
PURPOSE: Up-regulation of both inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) enzymes has been reported in colorectal cancer. We aimed at evaluating the possible interaction between the nitric oxide and COX-2 pathways, and its effect on promoting tumor angiogenesis. EXPERIMENTAL DESIGN: Expression of iNOS, COX-2, vascular endothelial growth factor (VEGF), and CD31 was analyzed in tumor samples and corresponding normal mucosa obtained from 46 surgical specimens. We also evaluated iNOS activity, prostaglandin E(2) (PGE(2)), cyclic GMP and cyclic AMP production in the same specimens. Nitrite/nitrate levels, and PGE(2) and VEGF production were assessed in HCT116 and HT29 colon cancer cell lines after induction and selective inhibition of the two enzyme pathways. RESULTS: A significant correlation was found between iNOS and COX-2 immunohistochemical expression. PGE(2) production significantly correlated with iNOS activity and cGMP levels. A significant correlation was also found among PGE(2) production, microvessel density, and VEGF expression. Coinduction of both iNOS and COX-2 activities occurred after lipopolysaccharide (LPS) and epidermal growth factor (EGF) treatment in HCT116 and HT29 cells. Inhibition of iNOS by 1400W significantly reduced both LPS- and EGF-induced PGE(2) production. Treatment with LPS, EGF, and arachidonic acid significantly increased VEGF production in the iNOS-negative/COX-2-positive HT29 cells. This effect was completely reversed by treatment with the selective COX-2 inhibitor celecoxib. CONCLUSIONS: Our data showed a prominent role of nitric oxide in stimulating COX-2 activity in colorectal cancer. This interaction is likely to produce a cooperative effect in promoting angiogenesis through PGE(2)-mediated increase in VEGF production.  相似文献   
94.
95.
96.

Purpose  

The blood–brain barrier discriminates the access of several molecules to the brain. This hampers the use of some drugs, as doxorubicin, potentially active for treatment of brain tumors. We explored the feasibility of active modification of the blood–brain barrier protection, by using morphine pretreatment, to allow doxorubicin accumulation in the brain in an animal model.  相似文献   
97.

Objective

Fabry's disease (FD) is an X‐linked lysosomal storage disease. Distal extremity pain can be an early finding and renal, cardiac, and cerebrovascular complications may lead to complications and mortality. Treatment is now available for these patients, who may not be diagnosed correctly for years if the neuropathic nature of the pain is not recognized. The aim of our study was to describe early clinical features in a cohort of patients with FD and to emphasize the importance of distal extremity pain for early diagnosis.

Methods

The medical charts of 35 patients with FD followed in a single center were reviewed. When data were incomplete, a detailed pain questionnaire was sent to patients. Nonresponders were contacted by telephone.

Results

Distal extremity pain was present in the majority of cases (25 of 35). The mean age at diagnosis of FD was 43.5 years (range 5–77 years). Distal extremity pain was more prevalent in males than females and occurred mostly in childhood or adolescence. When present at onset, the disease progressed with subsequent organ system involvement. Misdiagnoses were frequent and included growing pains, juvenile idiopathic arthritis, connective tissue disease, and gout.

Conclusion

Clinical manifestations of FD, including episodes of severe pain in the feet and hands, often start in childhood. Distal extremity pain may be the only symptom for a considerable period of time. Patients may be wrongly labeled as having rheumatologic conditions, resulting in long diagnostic and therapeutic delays. Rheumatologists should be aware of the clinical aspects of FD and include it in the differential diagnosis of distal extremity pain in childhood and adolescence.  相似文献   
98.
99.
To characterize a population of pediatric high-grade astrocytoma (HGA) patients by confirming the proportion with a correct diagnosis, and determine prognostic factors for survival in a subset diagnosed with uniform pathologic criteria. Sixty-three children diagnosed with HGA were treated at the Johns Hopkins Hospital between 1977 and 2004. A single neuropathologist (P.C.B.) reviewed all available histologic samples (n = 48). Log-rank analysis was used to compare survival by patient, tumor, and treatment factors. Median follow-up was 16 months for all patients and 155 months (minimum 54 months) for surviving patients. Median survival for all patients (n = 63) was 14 months with 10 long-term survivors (survival >48 months). At initial diagnosis, 27 patients were grade III (43%) and 36 grade IV (57%). Forty-eight patients had pathology slides available for review, including seven of ten long-term surviving patients. Four patients had non-HGA pathology, all of whom were long term survivors. The remaining 44 patients with confirmed HGG had a median survival of 14 months and prognostic analysis was confined to these patients. On multivariate analysis, five factors were associated with inferior survival: performance status (Lansky) <80% (13 vs. 15 months), bilaterality (13 vs. 19 months), parietal lobe location (13 vs. 16 months), resection less than gross total (13 vs. 22 months), and radiotherapy dose <50 Gy (9 vs. 16 months). Among patients with more than one of the five adverse factors (n = 27), median survival and proportion of long-term survivors were 12.9 months and 0%, compared with 41.4 months and 18% for patients with 0–1 adverse factors (n = 17). In an historical cohort of children with HGA, the potential for long term survival was confined to the subset with less than two of the following adverse prognostic factors: low performance status, bilaterality, parietal lobe site, less than gross total resection, and radiotherapy dose <50 Gy. Pathologic misdiagnosis should be suspected in patients who are long term survivors of a pediatric high grade astrocytoma.  相似文献   
100.
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