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   634篇
  免费   25篇
  国内免费   10篇
耳鼻咽喉   1篇
儿科学   8篇
妇产科学   18篇
基础医学   84篇
口腔科学   8篇
临床医学   34篇
内科学   84篇
皮肤病学   17篇
神经病学   13篇
特种医学   54篇
外国民族医学   1篇
外科学   100篇
综合类   18篇
预防医学   15篇
眼科学   17篇
药学   38篇
中国医学   13篇
肿瘤学   146篇
  2024年   2篇
  2023年   6篇
  2022年   33篇
  2021年   27篇
  2020年   17篇
  2019年   78篇
  2018年   132篇
  2017年   59篇
  2016年   22篇
  2015年   19篇
  2014年   97篇
  2013年   37篇
  2012年   25篇
  2011年   41篇
  2010年   10篇
  2009年   9篇
  2008年   11篇
  2007年   7篇
  2006年   6篇
  2005年   6篇
  2004年   2篇
  2003年   1篇
  2002年   1篇
  2001年   6篇
  2000年   2篇
  1999年   1篇
  1997年   1篇
  1993年   1篇
  1992年   1篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1981年   3篇
  1978年   1篇
排序方式: 共有669条查询结果,搜索用时 140 毫秒
91.
BACKGROUND AND PURPOSE: The human, rat, and mouse P2X(7) receptors have been previously characterized, and in this study we report the cloning and pharmacological properties of the guinea pig orthologue. EXPERIMENTAL APPROACH: A cDNA encoding for the guinea pig P2X(7) receptor was isolated from a guinea pig brain library. The receptor was expressed in U-2 OS cells using the BacMam viral expression system. A monoclonal antibody was used to confirm high levels of cell surface expression and the functional properties were determined in ethidium bromide accumulation studies. KEY RESULTS: The predicted guinea pig protein is one amino acid shorter than the human and rat orthologues and over 70% identical to the rat and human receptors. In contrast to human and rat P2X(7) receptors, 2'-&3'-O-(4benzoylbenzoyl)ATP (BzATP) was a partial agonist of the guinea pig P2X(7) receptor when compared to ATP and acted as an antagonist in some assays. However, as at other species orthologues, BzATP was more potent than ATP. The guinea pig P2X(7) receptor possessed higher affinity for 1-[N,O-bis(5-isoquinoline sulphonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine (KN62), suramin and Coomassie Brilliant Blue than human or rat P2X(7) receptors suggesting that it is pharmacologically different to other rodent or human P2X(7) receptors. CONCLUSIONS AND IMPLICATIONS: The guinea pig recombinant P2X(7) receptor displays a number of unique properties that differentiate it from the human, rat and mouse orthologues and this structural and functional information should aid in our understanding of the interaction of agonists and antagonist with the P2X(7) receptor.  相似文献   
92.
目的 探讨lncRNA DNM3OS对直肠癌SW-480细胞的增殖、凋亡以及放射敏感性的影响及分子机制.方法 选取30例直肠癌患者癌组织及癌旁组织,RT-qPCR检测DNM3OS和miR-193a-3p的表达水平;将抑制DNM3OS的表达载体、过表达miR-193a-3p载体转染至SW-480细胞,将DNM3OS与抑制...  相似文献   
93.
BackgroundA new staging system for patients with hepatocellular carcinoma (HCC) associated with portal vein tumor thrombus (PVTT) was developed by incorporating the good points of the BCLC classification of HCC, and by improving on the currently existing classifications of HCC associated with PVTT.MethodsUnivariate and multivariate analysis with Wald χ2 test were used to determinate the clinical prognostic factors for overall survival (OS) in patients with HCC and PVTT in the training cohort. Then the conditional inference trees analysis was applied to establish a new staging system.ResultsA training cohort of 2,179 patients from the Eastern Hepatobiliary Surgery Hospital and a validation cohort of 1,550 patients from four major liver centers in China were enrolled into establishing and validating a new staging system. The system was established by incorporating liver function, general health status, tumor resectability, extrahepatic metastasis and extent of PVTT. This staging system had a good discriminatory ability to separate patients into different stages and substages. The median OS for the two cohorts were 57.1 (37.2–76.9), 12.1 (11.0–13.2), 5.7 (5.1–6.2), 4.0 (3.3–4.6) and 2.5 (1.7–3.3) months for the stages 0 to IV, respectively (P<0.001) in the training cohort. The corresponding figures for the validation cohort were 6.4 (4.9–7.9), 2.8 (1.3–4.4), 10.8 (9.3–12.4), and 1.5 (1.3–1.7) months for the stages II to IV, respectively (P<0.001). The mean survival for stage 0 to 1 were 37.6 (35.9–39.2) and 30.4 (27.4–33.4), respectively (P<0.001).ConclusionsA new staging system was established which provided a good discriminatory ability to separate patients into different stages and substages after treatment. It can be used to supplement the other HCC staging systems.  相似文献   
94.
miR-363-3p has been shown to suppress tumor growth and metastasis in various human cancers. However, the function of miR-363-3p in osteosarcoma (OS) has not been determined. In our study, we found that the expression of miR-363-3p was significantly downregulated in OS tissues compared with adjacent normal tissues. miR-363-3p expression was associated with the poor overall survival rate of OS patients. Moreover, we found that overexpression of miR-363-3p markedly inhibited the proliferation, migration, and invasion of U2OS and MG63 cells. Moreover, we found that SOX4 was a direct target of miR-363-3p in OS cells. Overexpression of miR-363-3p significantly inhibited the expression of SOX4. Expression levels of miR-363-3p and SOX4 were negatively correlated in OS tissues. Finally, we found that restoration of SOX4 attenuated the suppressive effects of miR-363-3p on the proliferation, migration, and invasion of U2OS and MG63 cells. Therefore, our findings demonstrated that miR-363-3p served as a tumor suppressor in OS tissues by targeting SOX4.  相似文献   
95.
96.

Background

To investigate the potential to predict prognosis of glioblastoma (GBM) patients by analysis of the broader and lower values in the lower distribution of apparent diffusion coefficient (ADCL) (B&L-ADCL) values in the ADC histogram.

Background

Presurgical publicly available diffusion-weighted images (DWI) and contrast-enhanced T1-weighted images from 76 GBM patients were analyzed. With applied 2-mixture normal distribution in the ADC histogram of enhanced lesions on T1-weighted images, the mean and width of ADCL were analyzed. We dichotomized the lower mean of ADCL (L-ADCL) and the broader width of ADCL (B-ADCL) at their own average. B&L-ADCL was defined as B-ADCL with L-ADCL. Progression-free survival (PFS) and overall survival (OS) were determined by using Cox proportional hazards analysis and the Kaplan–Meier method with the log-rank test. The difference between PFS and OS was calculated.

Results

Six (7.89%) patients had B&L-ADCL values. B&L-ADCL was strongly associated with poor PFS (hazard risk: 5.747; P = 0.002) and OS (hazard risk: 3.331; P = 0.018). There were significant differences in PFS (median, 77 vs. 302 days; P < 0.001) and OS (median, 199 vs. 472 days; P = 0.004) between the patents with and without B&L-ADCL. There was no significant difference in the OS–PFS duration difference between the patients with (median, 79 days) and without B&L-ADCL (median, 132 days) (P = 0.348).

Conclusion

In this study, B&L-ADCL from pretreatment ADC analysis predicted poor PFS. B&L-ADCL may indicate higher cellularity and heterogeneity in GBM tumor tissue.  相似文献   
97.
98.
The tumor suppressor proteins p16 and p53 have been suggested to have prognostic value in some human papillomavirus (HPV)-associated cancers, however, this has been less well established for vulvar cancer. The aim of this review and meta-analysis was to examine the prognostic value of p16 and p53 expression status on survival after vulvar squamous cell carcinoma (VSCC). We conducted a thorough systematic literature search of multiple databases to identify studies examining survival after histolocally verified VSCC that were tested for p16 and/or p53. A total of 18 eligible studies were included. Using a fixed-effects model we calculated study-specific and pooled hazard ratios (HRs) of 5-year overall survival (OS). In the analyses of OS, we included 475 VSCC cases tested for p16 expression of which 38% were p16 positive. The pooled HRp16 was 0.40 (95% CI: 0.29–0.55). In addition, the majority of results from studies with adjusted analyses on the prognostic value of p16 indicated that p16 expression status could be an independent prognostic marker for OS in women diagnosed with VSCC, and the same pattern was seen for disease specific survival (DSS). We also included 310 VSCC cases tested for p53 expression of which 54% were p53 positive. The pooled HRp53 was 1.81 (95% CI: 1.22–2.68) indicating that p53 positive VSCC have a significantly lower 5-year OS compared to p53 negative. The results in relation to p53 reported from adjusted analyses OS and on DSS and disease free survival were more equivocal. This meta-analysis and review suggests that p53 and especially p16 expression status are of prognostic importance in women diagnosed with VSCC. This may be clinically important in the future design of targeted therapy and when planning the optimal follow-up strategy. Future studies should include the combined use of biomarkers such as p16, p53 and HPV status.  相似文献   
99.
100.

Purpose

To compare segmental radioembolization with segmental chemoembolization for localized, unresectable hepatocellular carcinoma (HCC) not amenable to ablation.

Materials and Methods

In a single-center, retrospective study (2010–2015), 101 patients with 132 tumors underwent segmental radioembolization, and 77 patients with 103 tumors underwent segmental doxorubicin-based drug-eluting embolic or conventional chemoembolization. Patients receiving chemoembolization had worse performance status (Eastern Cooperative Oncology Group 0, 76% vs 56%; P = .003) and Child-Pugh class (class A, 65% vs 52%; P = .053); patients receiving radioembolization had larger tumors (32 mm vs 26 mm; P < .001), more infiltrative tumors (23% vs 9%; P = .01), and more vascular invasion (18% vs 1%; P < .001). Toxicity, tumor response, tumor progression, and survival were compared. Analyses were weighted using a propensity score (PS).

Results

Toxicity rates were low, without significant differences. Index and overall complete response rates were 92% and 84% for radioembolization and 74% and 58% for chemoembolization (P = .001 and P < .001). Index tumor progression at 1 and 2 years was 8% and 15% in the radioembolization group and 30% and 42% in the chemoembolization group (P < .001). Median progression-free and overall survival were 564 days and 1,198 days in the radioembolization group and 271 days and 1,043 days in the chemoembolization group (PS-adjusted P = .002 and P = .35; censored by transplant PS-adjusted P < .001 and P = .064).

Conclusions

Segmental radioembolization demonstrates higher complete response rates and local tumor control compared with segmental chemoembolization for HCC, with similar toxicity profiles. Superior progression-free survival was achieved.  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