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381.
胃泌素瘤是一种神经内分泌肿瘤, 异位分泌胃泌素, 导致卓-艾综合征。大部分胃泌素瘤为散发病例, 20%~25%患者作为多发性内分泌腺瘤综合征1型(MEN1)临床表现之一存在。因为散发胃泌素瘤及MEN1治疗策略不同, 所以临床上需要将其加以区分。胃泌素瘤药物治疗主要分为控制高胃泌素血症相关症状和控制肿瘤生长两类。散发病例的手术治愈率为20%~40%, 而对于MEN1人群是否进行手术治疗尚存在争议。本文对近年来胃泌素瘤诊断及治疗相关临床进展进行阐释, 以期为临床工作提供参考。 相似文献
382.
Tianming Zhan Le Sun Yang Xu Minghua Wan Zebin Wu Zhenyu Lu 《Remote sensing letters.》2019,10(8):766-775
This paper presents a novel adaptive spectral-spatial kernel-based low-rank approximation method for spectral-spatial hyperspectral image (HSI) classification. In the first of three steps of the proposed method, superpixel and image patch are used together to calculate the weights in the homogeneous region. Second, an adaptive spectral-spatial kernel is defined to capture the spectral and spatial feature of HSIs. In the final step, an adaptive spectral-spatial kernel and low-rank approximation are integrated into a decision model to perform HSI classification. Extensive experimental results on Indian Pines and Pavia University demonstrate the superiority of the proposed classifier when compared with other competing classifiers. 相似文献
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Yue Zhang Song Xu Jun Lin Guangyu Yao Zelong Han Bo Liang Zhenhong Zou Zhenguo Chen Qiancheng Song Yifan Dai Tianming Gao Anling Liu Xiaochun Bai 《Breast cancer research and treatment》2012,136(2):379-388
Nordihydroguaiaretic acid (NDGA) is a natural phenolic compound isolated from the creosote bush Larrea divaricata, which has anti-tumor activities both in vitro and in vivo. Its analogs are in clinical development for use in refractory solid tumors. But the mechanisms underlying the anti-cancer effect of NDGA are not fully understood. In this study, we identified mammalian target of rapamycin complex 1 (mTORC1) as a target of NDGA both in cultured breast cancer cells and in xenograft models. NDGA effectively inhibited basal level of mTORC1 but not mTORC2 activity in breast cancer cell lines. NDGA also suppressed mTORC1 downstream signaling such as expression of cyclin D1, hypoxia-inducible factor-?? and VEGF, and prevented proliferation in breast cancer cells. Although NDGA stimulated AMP-activated protein kinase (AMPK)/tuberous sclerosis complex 2 (TSC2) signaling, which negatively regulates mTORC1, AMPK and TSC2 deletion could not diminish the inhibition of mTORC1 by NDGA. Subsequent studies revealed that NDGA may also direct target mTORC1 complex because NDGA suppressed amino acids- and insulin-stimulated mTORC1 and acted like rapamycin to disrupt mTOR?CRaptor interaction. Most importantly, NDGA repressed breast tumor growth and targeted mTORC1 and its downstream signaling in xenograft models. Together our data provide a novel mechanism for NDGA activity which could help explain its anti-cancer activity. Disruption of mTOR?CRaptor complex and activation of AMPK/TSC signaling may contribute to inhibitory effects of NDGA against mTORC1. Our data also raise the possibility that NDGA, as an mTORC1 inhibitor, may have a broad spectrum of action on breast cancers. 相似文献
386.
Liu T Lu J Wang Y Campbell WA Huang L Zhu J Xia W Wong ST 《Journal of neuroscience methods》2006,153(2):190-202
An integrated microscope image analysis pipeline is developed for automatic analysis and quantification of phenotypes in zebrafish with altered expression of Alzheimer's disease (AD)-linked genes. We hypothesize that a slight impairment of neuronal integrity in a large number of zebrafish carrying the mutant genotype can be detected through the computerized image analysis method. Key functionalities of our zebrafish image processing pipeline include quantification of neuron loss in zebrafish embryos due to knockdown of AD-linked genes, automatic detection of defective somites, and quantitative measurement of gene expression levels in zebrafish with altered expression of AD-linked genes or treatment with a chemical compound. These quantitative measurements enable the archival of analyzed results and relevant meta-data. The structured database is organized for statistical analysis and data modeling to better understand neuronal integrity and phenotypic changes of zebrafish under different perturbations. Our results show that the computerized analysis is comparable to manual counting with equivalent accuracy and improved efficacy and consistency. Development of such an automated data analysis pipeline represents a significant step forward to achieve accurate and reproducible quantification of neuronal phenotypes in large scale or high-throughput zebrafish imaging studies. 相似文献
387.
目的探讨中老年男性在应用双能X线骨密度仪检测不同部位骨密度时应关注检测的部位。方法选取2012年9月至2014年12月在我院行双能骨密度检测的中老年男性,比较腰椎、髋部、前臂桡骨下1/3的骨密度(BMD)和T值。结果中老年男性腰椎、髋部、前臂桡骨下1/3三个部位的BMD和T值比较,P0.001差异有统计学意义。随着年龄逐渐增大,腰椎BMD和T值下降不明显,髋部、前臂BMD和T值60岁以后才逐渐降低,前臂T值下降幅度明显大于腰椎和髋部。随着年龄的增加,髋部及前臂骨质疏松检出率也逐渐增加,但腰椎骨质疏松检出率随年增加反而下降。结论应用双能X线骨密度仪检测腰椎、髋部、前臂3个部位,经比较发现老年男性髋部和前臂BMD和T值明显低于腰椎,而且腰椎BMD和T值相对平稳,提示对老年男性骨质疏松诊断应同时检测髋部和前臂骨密度,以免出现骨质疏松的漏诊。 相似文献
388.
Long noncoding RNA cancer upregulated drug resistant (CUDR) is overexpressed in many tumors and promotes tumorigenesis. Herein, we demonstrate CUDR could enhance the human embryonic stem cells (ESC) differentiation into hepatocyte-like cells by reducing trimethylation on histone H3 twenty-seventh lysine (H3K27me3). On the other hand, excessive CUDR triggers hepatocyte-like cells malignant transformation. Mechanistically, we identify CUDR causes highly upregulated in liver cancer (HULC) and β-catenin abnormal expression by inhibiting HULC promoter methylation and promoting β-catenin promoter-enhancer chromatin looping formation mediated by CUDR-ccctc-binding factor (CTCF) complex, which recruits more RNA polII and P300. Strikingly, HULC and β-catenin activity are crucial for CUDR oncogenic function. These findings provide the first demonstration that CUDR plays a positive potential role in liver cancer stem cell through the cascade of CUDR-HULC/CUDR-β-catenin signaling, and offer insights into a novel link between long noncoding RNA (lncRNA) and the epigenetic modification in cancer stem cells. 相似文献
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Shijie Zhao Junwei Han Xintao Hu Xi Jiang Jinglei Lv Tuo Zhang Shu Zhang Lei Guo Tianming Liu 《Brain imaging and behavior》2018,12(3):743-757
Recently, a growing body of studies have demonstrated the simultaneous existence of diverse brain activities, e.g., task-evoked dominant response activities, delayed response activities and intrinsic brain activities, under specific task conditions. However, current dominant task-based functional magnetic resonance imaging (tfMRI) analysis approach, i.e., the general linear model (GLM), might have difficulty in discovering those diverse and concurrent brain responses sufficiently. This subtraction-based model-driven approach focuses on the brain activities evoked directly from the task paradigm, thus likely overlooks other possible concurrent brain activities evoked during the information processing. To deal with this problem, in this paper, we propose a novel hybrid framework, called extendable supervised dictionary learning (E-SDL), to explore diverse and concurrent brain activities under task conditions. A critical difference between E-SDL framework and previous methods is that we systematically extend the basic task paradigm regressor into meaningful regressor groups to account for possible regressor variation during the information processing procedure in the brain. Applications of the proposed framework on five independent and publicly available tfMRI datasets from human connectome project (HCP) simultaneously revealed more meaningful group-wise consistent task-evoked networks and common intrinsic connectivity networks (ICNs). These results demonstrate the advantage of the proposed framework in identifying the diversity of concurrent brain activities in tfMRI datasets. 相似文献