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   1175篇
  免费   99篇
  国内免费   6篇
耳鼻咽喉   14篇
儿科学   46篇
妇产科学   19篇
基础医学   157篇
口腔科学   35篇
临床医学   137篇
内科学   222篇
皮肤病学   41篇
神经病学   110篇
特种医学   15篇
外科学   135篇
综合类   12篇
预防医学   94篇
眼科学   19篇
药学   120篇
肿瘤学   104篇
  2024年   2篇
  2023年   22篇
  2022年   12篇
  2021年   31篇
  2020年   19篇
  2019年   41篇
  2018年   39篇
  2017年   35篇
  2016年   48篇
  2015年   42篇
  2014年   47篇
  2013年   63篇
  2012年   96篇
  2011年   116篇
  2010年   53篇
  2009年   43篇
  2008年   81篇
  2007年   71篇
  2006年   60篇
  2005年   53篇
  2004年   67篇
  2003年   58篇
  2002年   54篇
  2001年   5篇
  2000年   8篇
  1999年   10篇
  1998年   9篇
  1997年   12篇
  1996年   11篇
  1995年   4篇
  1994年   8篇
  1993年   14篇
  1992年   7篇
  1991年   1篇
  1990年   8篇
  1989年   1篇
  1988年   2篇
  1986年   5篇
  1985年   4篇
  1984年   1篇
  1983年   4篇
  1982年   3篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   2篇
  1970年   2篇
  1963年   1篇
排序方式: 共有1280条查询结果,搜索用时 163 毫秒
11.
Recently, extensive stromal fibroblast contamination has been reported in the modified Courtenay-Mills soft agar clonogenic assay for cellular in vitro radiosensitivity in tumour biopsies. The aim of the present study was to evaluate the hypothesis that an immunocytochemical analysis added to the modified Courtenay-Mills soft agar clonogenic assay provides a measure of both fibroblast and tumour cell radiosensitivity. Therefore, fibroblasts derived from squamous cell carcinomas of the head and neck, and from the surrounding oral mucosa were compared for immunocytochemistry, DNA ploidy, plating efficiency and surviving fraction of cells after a radiation dose of 2 Gy. The results of our study suggest that the stromal fibroblasts derived from tumour biopsies are representative of normal fibroblasts with respect to the characteristics examined using mucosal fibroblasts as normal controls.  相似文献   
12.
13.
14.
The aim of this study was to describe the dynamics of HIF‐1α, GLUT‐1, Bcl‐2 and Ki‐67 during chemoradiotherapy (CRT) of rectal cancer, and to investigate the fluctuation of these biomarkers in relation to pathological response to CRT. The study included 86 patients with rectal adenocarcinoma receiving preoperative CRT (>50.4 Gy and Uracil/Tegafur). Immunohistological expressions of HIF‐1α, GLUT‐1, Bcl‐2 and Ki‐67 were investigated in biopsies taken before treatment, after 2, 4 and 6 weeks of CRT and in specimens from the operation. Decreasing expressions of HIF‐1α, Bcl‐2 and Ki‐67 were observed during CRT, whereas GLUT‐1 overall was unchanged. No significant changes of the markers were observed in the interval between CRT and surgery. A significant association was observed between the presence of residual carcinoma after 6 weeks of treatment and pathological response to CRT, but no association was seen between the fluctuations of any of the markers and response to CRT. This unique material containing specimens before, after and during CRT for rectal cancer demonstrated biological dynamics in HIF‐1α, Bcl‐2 and Ki‐67, but not GLUT‐1, expression during CRT, and a significant association was seen between the presence of residual carcinoma after 6 weeks of treatment and pathological response to CRT.  相似文献   
15.
Background Isolating sufficient material for molecular testing remains challenging in non-small cell lung cancer (NSCLC). The use of new ultra-microsamples (uMS) is proven sufficient for DNA and mRNA detection, but whether uMS are useful for quantifying mRNA expression is unknown. We investigated if uMS from lung cancer patients can be used to generate quantitative data on mRNA expression. Methods uMS were collected from primary tumors and lymph nodes from patients suspected of having lung cancer. mRNA was isolated, reverse-transcribed into cDNA and quantified with quantitative PCR assays for hepatocyte growth factor receptor (MET), hepatocyte growth factor (HGF), epidermal growth factor receptor (EGFR) and amphiregulin (AREG) mRNA. The fraction of tumor cells to normal cells was estimated in each sample. Results MET, HGF, EGFR, and AREG expression were evaluated in 90 samples (30 containing cancer cells and 60 without cancer cells). MET and EGFR expression were negligible in samples without cancer cells. In samples containing cancer cells, MET and EGFR could be quantified in 13 samples each. Adjustment for tumor-cell fraction made it possible to obtain a quantitative result for the tumor-cell mRNA expression of MET and EGFR. In contrast, AREG and HGF were expressed in samples without tumor cells. These samples were used to establish the AREG and HGF mRNA expression in normal cells. Seven out of 14?AR-positive and two out of eight HGF-positive samples with tumor cells were above a cut-off of the mean?+?2SD established in samples without tumor cells. Conclusion We demonstrate that uMS contain high-quality mRNA, and quantitative studies can be performed when the tumor-cell fraction is considered.  相似文献   
16.

Objectives

This randomized controlled trial tested the hypothesis that children with non‐high‐risk acute lymphoblastic leukemia could benefit from individualized 6‐mercaptopurine increments during consolidation therapy (NCT00816049). Primary and secondary end points were end of consolidation minimal residual disease (MRD) positivity and event‐free survival.

Methods

392 patients were randomized to experimental and 396 to standard therapy. Patients allocated to standard therapy received oral 6‐mercaptopurine (25 mg/m2/day) from days 30 to 85, while the experimental arm received stepwise increments of additional 25 mg/m2/day beginning on days 50 and/or 71 unless dose‐limiting myelosuppression had occurred.

Results

In the experimental arm, 166 patients (42%) received one dose increment, and 62 (16%) received two. Fifty‐seven of 387 (15%) patients in the experimental arm were MRD positive at end of consolidation vs 77 of 389 (20%) in the control arm (P = .08). Five‐year probability of event‐free survival was 0.89 (95% CI: 0.85‐0.93) in the experimental arm vs 0.93 (0.90‐0.96) in the control arm (P = .13). The median accumulated length of 6‐mercaptopurine treatment interruptions was 7 (IQR 2‐12) in the experimental arm vs 4 (IQR 0‐10) in the control arm (P = .002).

Conclusion

This study found no benefit from individualized 6‐mercaptopurine increments compared to standard therapy.  相似文献   
17.
18.

Background

Life expectancy of people with severe mental illness (SMI) is greatly shortened compared to the general population, and despite extensive research, this issue is unsolved. Although it is widely recognised that people with SMI need support from health care services to manage health related issues, profound health inequalities exist within provision of health care. The aim of this study was to examine how mental health care professionals accounted for their actions and responsibilities related to managing physical health issues among people with SMI.

Methods

Three focus groups were conducted with 22 mental health care professionals, employed at three mental health care locations. Participants' situated accounts were subjected to discourse analysis.

Results

Participants accounted for actions and responsibilities in three typical ways; 1) by positioning people with SMI as difficult to motivate and actively resisting intervention, 2) by positioning people with SMI as so impaired that intervention was futile, and 3) by arguing they are undertreated for physical conditions and might have physical illnesses that staff are not aware of because of prominent mental illness. These discursive strategies seemed to legitimise situations where participants described not responding to physical health issues, and to downplay potential trouble in situations where participants described not succeeding in facilitating lifestyle changes or promoting compliance to treatment of physical conditions.

Discussion and conclusion

Mental health care professionals need to increase their awareness of latent discriminating attitudes towards people with SMI. Such attitudes are suggested to reinforce barriers for people with SMI receiving physical health care.  相似文献   
19.
This study aimed to investigate if combined analysis of pro‐Neuropeptide Y (NPY) and ERG expression in tumor tissue are associated with biochemical failure (BF), castration‐based treatment, castration‐resistant prostate cancer (CRPC), and prostate cancer (PCa)‐specific death for men undergoing radical prostatectomy (RP) for PCa. This study included 315 patients, who underwent RP from 2002 to 2005. Both pro‐NPY and ERG expression were analyzed using immunohistochemistry and were scored as low or high and negative or positive, respectively. Risk of BF, castration‐based treatment, CRPC, and PCa‐specific death were analyzed with multiple cause‐specific Cox regression analyses and stratified cumulative incidences using competing risk assessment. Median follow‐up was 13.0 years (95% CI: 12.7–13.2). In total, 85.7% were pro‐NPY high and 14.3% were pro‐NPY low. The combined analyses of pro‐NPY and ERG expression was not associated with risk of BF (p = 0.7), castration‐based treatment (p = 0.8), CRPC (p = 0.4) or PCa‐specific death (p = 0.5). In the multiple cause‐specific Cox regression analysis, pro‐NPY high and ERG positivity was not associated with BF (HR: 1.02; 95% CI 0.6–1.7; p = 0.94). In conclusion the combination of pro‐NPY and ERG expression did not show association with risk of BF, castration‐based treatment, CRPC, and PCa‐specific death following RP.  相似文献   
20.
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