全文获取类型
收费全文 | 2479篇 |
免费 | 182篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 44篇 |
妇产科学 | 26篇 |
基础医学 | 739篇 |
口腔科学 | 25篇 |
临床医学 | 164篇 |
内科学 | 468篇 |
皮肤病学 | 64篇 |
神经病学 | 317篇 |
特种医学 | 31篇 |
外国民族医学 | 1篇 |
外科学 | 86篇 |
综合类 | 212篇 |
预防医学 | 14篇 |
眼科学 | 63篇 |
药学 | 161篇 |
中国医学 | 23篇 |
肿瘤学 | 281篇 |
出版年
2024年 | 1篇 |
2023年 | 23篇 |
2022年 | 26篇 |
2021年 | 63篇 |
2020年 | 56篇 |
2019年 | 56篇 |
2018年 | 42篇 |
2017年 | 47篇 |
2016年 | 69篇 |
2015年 | 101篇 |
2014年 | 119篇 |
2013年 | 127篇 |
2012年 | 122篇 |
2011年 | 115篇 |
2010年 | 120篇 |
2009年 | 129篇 |
2008年 | 135篇 |
2007年 | 105篇 |
2006年 | 99篇 |
2005年 | 103篇 |
2004年 | 128篇 |
2003年 | 80篇 |
2002年 | 90篇 |
2001年 | 72篇 |
2000年 | 75篇 |
1999年 | 62篇 |
1998年 | 54篇 |
1997年 | 67篇 |
1996年 | 55篇 |
1995年 | 69篇 |
1994年 | 54篇 |
1993年 | 45篇 |
1992年 | 32篇 |
1991年 | 38篇 |
1990年 | 23篇 |
1989年 | 24篇 |
1988年 | 25篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有2725条查询结果,搜索用时 31 毫秒
1.
2.
《Clinical lung cancer》2019,20(6):e638-e651
BackgroundThe purpose of the study was to investigate the potential of a radiomic signature developed in a general non–small-cell lung cancer (NSCLC) cohort for predicting the overall survival of anaplastic lymphoma kinase (ALK)-positive (ALK+) patients with different treatment types.Materials and MethodsAfter test-retest in the Reference Image Database to Evaluate Therapy Response data set, 132 features (intraclass correlation coefficient > 0.9) were selected in the least absolute shrinkage and selection operator Cox regression model with a leave-one-out cross-validation. The NSCLC radiomics collection from The Cancer Imaging Archive was randomly divided into a training set (n = 254) and a validation set (n = 63) to develop a general radiomic signature for NSCLC. In our ALK+ set, 35 patients received targeted therapy and 19 patients received nontargeted therapy. The developed signature was tested later in this ALK+ set. Performance of the signature was evaluated with the concordance index (C-index) and stratification analysis.ResultsThe general signature had good performance (C-index > 0.6; log rank P < .05) in the NSCLC radiomics collection. It includes 5 features: Geom_va_ratio, W_GLCM_Std, W_GLCM_DV, W_GLCM_IM2, and W_his_mean. Its accuracy of predicting overall survival in the ALK+ set achieved 0.649 (95% confidence interval [CI], 0.640-0.658). Nonetheless, impaired performance was observed in the targeted therapy group (C-index = 0.573; 95% CI, 0.556-0.589) whereas significantly improved performance was observed in the nontargeted therapy group (C-index = 0.832; 95% CI, 0.832-0.852). Stratification analysis also showed that the general signature could only identify high- and low-risk patients in the nontargeted therapy group (log rank P = .00028).ConclusionThis preliminary study suggests that the applicability of a general signature to ALK+ patients is limited. The general radiomic signature seems to be only applicable to ALK+ patients who had received nontargeted therapy, which indicates that developing special radiomics signatures for patients treated with tyrosine kinase inhibitors might be necessary. 相似文献
3.
4.
5.
《European journal of surgical oncology》2020,46(11):2023-2028
IntroductionThe lymph node ratio (LNR), which represents the proportion of metastatic lymph nodes resected, has been found to be a prognostic variable in several cancers, but data for Medullary thyroid carcinoma (MTC) are sparse. The aim of this study was to determine the value of the LNR in predicting outcome in patients with MTC.Materials and methodsA retrospective multicenter study design of 107 patients with MTC who underwent total thyroidectomy with neck dissection between 1984 and 2016. The association of LNR with patient and tumor characteristics and prognostic factors was evaluated.ResultsStudy population consisted of 53.3% female, mean age at diagnosis was 50.3 ± 18.4 years; 16.8% had inherited MTC. LNR was positively correlated with tumor size (p = 0.018) and inversely correlated with age at diagnosis (p = 0.024). A higher LNR was associated with extrathyroidal extension (p < 0.001), multifocality (p = 0.001), bilateral tumor (p = 0.002), distant metastases (p < 0.001), and tumor recurrence (OR = 14.7, p < 0.001). LNR was also correlated to postoperative calcitonin levels (p < 0.001) and carcinoembryonic antigen (p = 0.011). LNR >0.1 was associated with shorter disease-specific survival in patients at risk: tumor larger than 20 mm at diagnosis (p = 0.013), sporadic MTC (p = 0.01), and age above 40 years at diagnosis (p = 0.004). Cox multivariate survival analysis revealed LNR as the only significant independent factor for disease free survival (p = 0.005).ConclusionsThis study showed that LNR correlates well with patient and tumor characteristics and prognostic variables. We suggest that LNR should be considered an important parameter for predicting outcome in MTC. 相似文献
6.
CD2AP inhibits metastasis in gastric cancer by promoting cellular adhesion and cytoskeleton assembly
Wangkai Xie Chao Chen Zheng Han Jingjing Huang Xin Liu Hongjun Chen Teming Zhang Sian Chen Chenbin Chen Mingdong Lu Xian Shen Xiangyang Xue 《Molecular carcinogenesis》2020,59(4):339-352
Diffuse gastric cancer (DGC) is a lethal malignancy lacking effective systemic therapy. Among the most provocative recent results in DGC has been that the alter of the cellular cytoskeleton and intercellular adhesion. CD2-associated protein (CD2AP) is one of the critical proteins regulating cytoskeleton assembly and intercellular adhesion. However, no study has investigated the expression and biological significance of CD2AP in gastric cancer (GC) to date. Therefore, the aim of our study was to explore if the expression of CD2AP is associated with any clinical features of GC and to elucidate the underlying mechanism. Immunohistochemistry of 620 patient tissue samples indicated that the expression of CD2AP is downregulated in DGC. Moreover, a low CD2AP level was indicative of poor patient prognosis. In vitro, forced expression of CD2AP caused a significant decrease in the migration and invasion of GC cells, whereas depletion of CD2AP had the opposite effect. Immunofluorescence analysis indicated that CD2AP promoted cellular adhesion and influenced cell cytoskeleton assembly via interaction with the F-actin capping protein CAPZA1. Overall, the upregulation of CD2AP could attenuate GC metastasis, suggesting CD2AP as a novel biomarker for the prognosis and treatment of patients with GC. 相似文献
7.
Actin cytoskeleton is crucial to support spermatogenesis in the mammalian testis. However, the molecular mechanism(s) underlying changes of actin cytoskeletal organization in response to cellular events that take place across the seminiferous epithelium (e.g., self-renewal of spermatogonial stem cells, germ cell differentiation, meosis, spermiogenesis, spermiation) at specific stages of the epithelial cycle of spermatogenesis remain largely unexplored. This, at least in part, is due to the lack of suitable study models to identify the crucial regulatory proteins and to investigate how these proteins work in concert to support actin dynamics. Much of the information on the role of actin binding proteins in the literature, namely the actin bundling proteins, actin nucleation proteins and motor proteins, are either findings based on genetic models or morphological analyses. While this information is helpful to delineate the function of these proteins to support spermatogenesis, they are not helpful to identify the regulatory signaling proteins, the signaling pathways and the cascade of events to modulate actin cytoskeleton dynamics. Recent studies based on the use of toxicant models, both in vitro and in vivo, however, have bridged this gap by identifying putative regulatory and signaling proteins of actin cytoskeleton. Herein, we summarize and critically evaluate these findings. We also provide a hypothetical model by which actin cytoskeletal dynamics in Sertoli cells are regulated, which in turn supports spermatid transport across the seminiferous epithelium, and at the blood-testis barrier (BTB) during the epithelial cycle of spermatogenesis. 相似文献
8.
Primary cutaneous anaplastic large cell lymphomas with 6p25.3 rearrangement exhibit particular histological features 下载免费PDF全文
9.
10.
《Clinical lung cancer》2020,21(5):e349-e354
BackgroundRearranged during transfection (RET) proto-oncogene gene fusions are rare in non–small-cell lung cancer (NSCLC). We compared the efficacy of pemetrexed-based chemotherapy with other chemotherapy regimens in patients with NSCLC with different RET fusion subtypes.Patients and MethodsA retrospective, multicenter study of patients with pathologically confirmed stage IIIB/IV lung adenocarcinomas was conducted. RET rearrangements were detected using next generation sequencing. We analyzed the clinical characteristics of patients with RET-rearranged NSCLC and the efficacy of chemotherapy regimens. We also evaluated the efficacy between groups of patients with and without KIF5B-RET–rearranged lung cancer.ResultsWe evaluated 62 patients with NSCLC and RET rearrangements, including 41 with KIF5B-RET, 15 with CCDC6-RET, and 6 with other rare fusion subtypes. Of these 62 patients, 50 had stage IIIB/IV. We also evaluated 40 patients with first-line chemotherapy information available. The median progression-free survival was significantly different between those receiving pemetrexed-based chemotherapy and those receiving other chemotherapy regimens (9.2 vs. 5.2 months; P = .007). The median progression-free survival for patients with KIF5B-RET fusion and non–KIF5B-RET fusion was not significantly different statistically (7.8 vs. 11.2 months; P = .847). For second-line chemotherapy, a statistically significant difference was found between the chemotherapy regimens (4.9 vs. 2.8 months; P = .049). Survival follow-up data were available for 38 patients with advanced NSCLC. The median overall survival was 26.4 months. The overall survival of the patients with RET-rearranged NSCLC who had received pemetrexed-based chemotherapy versus no pemetrexed-based chemotherapy was 35.2 versus 22.6 months (P = .052). No difference in survival was observed between the patients with KIF5B-RET and non–KIF5B-RET rearrangements.ConclusionsPemetrexed-based treatment should be considered first when selecting the chemotherapy regimen for patients with NSCLC and RET rearrangements. 相似文献