249 research outputs found

    High Level of CXCR4 in Triple-Negative Breast Cancer Specimens Associated with a Poor Clinical Outcome

    Get PDF
    Despite high sensitivity to chemotherapy, the prognosis for triple-negative breast cancer (TNBC) remains poor because of its high rate of metastasis and low sensitivity to endocrine therapy. CXCR4 expression has been reported in many subtypes of human breast cancers, but it remains unknown whether CXCR4 is expressed in TNBC and whether CXCR4 expression in TNBC could be a prognostic indicator. TNBCs tissues were formalin fixed, paraffin embedded and hematoxylin-eosin (H&E) stained. Immunohistochemical staining was utilized to determine the CXCR4 expression in those specimens. Statistical analyses were performed using SPSS16.0 software to reveal the correlation of CXCR4 expression in TNBC specimens and cancer recurrence and cancer-related death. Our results showed that there was a strong association between CXCR4 overexpression and both menopause and the histological cancer grade of TNBC patients (p values were separately 0.004 and 0.001). The 5-y disease-free survival (DFS) and the 5-y overall survival (OS) were 57.69% and 58.33% for the low-CXCR4 group versus 42.11% and 44.74% for the high-CXCR4 group, respectively (p0.031 and 0.048). CXCR4 overexpression plays an important role in triple-negative breast cancers, and may be a predictor of poor prognosis

    Enabling smartphone-based HD video chats by cooperative transmissions in CRNs

    Get PDF
    Smartphones have been equipped with the cameras that can shoot HD videos, and the video chat apps such as Skype are becoming popular. We can, therefore, intuitively predict the trend that users are expecting to enjoy HD video chats via utilizing their smartphones. Most of the current Internet services, however, cannot support the live HD video transmissions because of their low uplink rate. In order to overcome this limit, we propose to offload the uplink transmissions to cooperative users via cognitive radio networks. Specifically, we first divide the video stream into several substreams according to the H.264/SVC standard and the cooperative users’ uplink rates. Then, the cooperative users are selected by employing our proposed optimal multiple stopping method. Finally, the substreams are assigned to the selected cooperative users by a 0-1 Knapsack-based allocation algorithm. The simulation results demonstrate that our proposed scheme can successfully support 720P HD video chats

    Being there and being with them: the effects of visibility affordance of online short fitness video on users’ intention to cloud fitness

    Get PDF
    IntroductionCloud fitness is transforming indoor exercise for young people in China. Recent studies have explored the correlation between media use and health-promoting behavior by examining the motivation of individuals and the credibility of influencers. However, the role of media affordance has thus far been largely overlooked. Drawing on the theory of Stimulus-Organism-Response (SOR), the study investigated the indirect effect of visibility affordance on the intention to exercise with fitness influencers in the context of cloud fitness through psychological variables.MethodsThis paper, based on the online survey data (N = 456), analyses the effect of visibility affordance on the intention to fitness following with influencers. A moderated parallel mediation model was constructed to examine the relationship among related variables.ResultsThe paper draws the following conclusions: (1) Visibility affordance is positively related to the intention to exercise with fitness influencers. (2) Both the sense of social presence and immersion positively mediate the relationship between visibility affordance and the intention to exercise with fitness influencers. (3) The perceived popularity of the influencer positively moderates the relationship between social presence and the intention to exercise with fitness influencers and moderates the mediating role of social presence.DiscussionConsequently, this study enhances the existing body of knowledge in exercise behavior and health communication literature, and provides practical implications for short video platform, influencers and individuals in promoting healthier behaviors

    Ultrasound Image Segmentation of Thyroid Nodule via Latent Semantic Feature Co-Registration

    Full text link
    Segmentation of nodules in thyroid ultrasound imaging plays a crucial role in the detection and treatment of thyroid cancer. However, owing to the diversity of scanner vendors and imaging protocols in different hospitals, the automatic segmentation model, which has already demonstrated expert-level accuracy in the field of medical image segmentation, finds its accuracy reduced as the result of its weak generalization performance when being applied in clinically realistic environments. To address this issue, the present paper proposes ASTN, a framework for thyroid nodule segmentation achieved through a new type co-registration network. By extracting latent semantic information from the atlas and target images and utilizing in-depth features to accomplish the co-registration of nodules in thyroid ultrasound images, this framework can ensure the integrity of anatomical structure and reduce the impact on segmentation as the result of overall differences in image caused by different devices. In addition, this paper also provides an atlas selection algorithm to mitigate the difficulty of co-registration. As shown by the evaluation results collected from the datasets of different devices, thanks to the method we proposed, the model generalization has been greatly improved while maintaining a high level of segmentation accuracy

    Future tropospheric ozone budget and distribution over east Asia under a net-zero scenario

    Get PDF
    Under future net-zero emission policies, reductions in emissions of ozone (O3) precursors are expected to alter the temporal and spatial distributions of tropospheric O3. In this study, we quantify changes in the tropospheric O3 budget and in the spatiotemporal distribution of surface O3 in east Asia and the contributions of regional emissions, intercontinental transport and climate change between the present day and 2060 under a net-zero scenario using the NCAR Community Earth System Model (CESM) with online tagging of O3 and its precursors. The results reveal that the global tropospheric O3 burden is likely to decrease by more than 20%, from 316Tg in the present day to 247Tg in 2060, under a net-zero scenario. The burden of stratospheric O3 in the troposphere is expected to increase from 69 to 77Tg. The mean lifetime of tropospheric O3 is expected to increase by 2d (∌10%). Changes in climate under a net-zero pathway are relatively small and only lead to small increases in tropospheric O3. Over eastern China, surface O3 increases in winter due to the weakened titration of O3 by NO associated with reduced anthropogenic NO emissions and due to enhanced stratospheric input. In summer, surface O3 decreases by more than 30ppbv, and peak concentrations shift from July to May. Local contributions from anthropogenic emissions to surface O3 over east Asia are highest in summer but drop substantially, from 30% to 14%, under a net-zero scenario. The contribution of biogenic NO sources is enhanced and forms the dominant contributor to future surface O3, especially in summer (∌40%). This enhanced contribution is mainly due to the increased O3 production efficiency under lower anthropogenic precursor emissions. Over eastern China, local anthropogenic contributions decrease from 50% to 30%. The decreases in surface O3 are strongly beneficial and are more than sufficient to counteract the increases in surface O3 observed in China over recent years. This study thus highlights the important co-benefits of net-zero policies that target climate change in addressing surface O3 pollution over east Asia

    p21-activated kinase is involved in the sporulation, pathogenicity, and stress response of Arthrobotrys oligospora under the indirect regulation of Rho GTPase-activating protein

    Get PDF
    The p21-GTPase-activated protein kinases (PAKs) participate in signal transduction downstream of Rho GTPases, which are regulated by Rho GTPase-activating proteins (Rho-GAP). Herein, we characterized two orthologous Rho-GAPs (AoRga1 and AoRga2) and two PAKs (AoPak1 and AoPak2) through bioinformatics analysis and reverse genetics in Arthrobotrys oligospora, a typical nematode-trapping (NT) fungus. The transcription analyses performed at different development stages suggested that Aopaks and Aorga1 play a crucial role during sporulation and trap formation, respectively. In addition, we successfully deleted Aopak1 and Aorga1 via the homologous recombination method. The disruption of Aopak1 and Aorga1 caused a remarkable reduction in spore yield and the number of nuclei per cell, but did not affect mycelial growth. In ∆Aopak1 mutants, the trap number was decreased at 48 h after the introduction of nematodes, but nematode predatory efficiency was not affected because the extracellular proteolytic activity was increased. On the contrary, the number of traps in ∆Aorga1 mutants was significantly increased at 36 h and 48 h. In addition, Aopak1 and Aorga1 had different effects on the sensitivity to cell-wall-disturbing reagent and oxidant. A yeast two-hybrid assay revealed that AoPak1 and AoRga1 both interacted with AoRac, and AoPak1 also interacted with AoCdc42. Furthermore, the Aopaks were up-regulated in ∆Aorga1 mutants, and Aorga1 was down-regulated in ∆Aopak1 mutants. These results reveal that AoRga1 indirectly regulated AoPAKs by regulating small GTPases

    Accelerated Policy Evaluation: Learning Adversarial Environments with Adaptive Importance Sampling

    Full text link
    The evaluation of rare but high-stakes events remains one of the main difficulties in obtaining reliable policies from intelligent agents, especially in large or continuous state/action spaces where limited scalability enforces the use of a prohibitively large number of testing iterations. On the other hand, a biased or inaccurate policy evaluation in a safety-critical system could potentially cause unexpected catastrophic failures during deployment. In this paper, we propose the Accelerated Policy Evaluation (APE) method, which simultaneously uncovers rare events and estimates the rare event probability in Markov decision processes. The APE method treats the environment nature as an adversarial agent and learns towards, through adaptive importance sampling, the zero-variance sampling distribution for the policy evaluation. Moreover, APE is scalable to large discrete or continuous spaces by incorporating function approximators. We investigate the convergence properties of proposed algorithms under suitable regularity conditions. Our empirical studies show that APE estimates rare event probability with a smaller variance while only using orders of magnitude fewer samples compared to baseline methods in both multi-agent and single-agent environments.Comment: 10 pages, 5 figure

    Monitoring Technology of Surrounding Rock Deformation Based on IWFBG Sensing Principle and Its Application

    Get PDF
    To address the challenge of achieving precise real-time monitoring of significant deformation in deep roadway surrounding rock, a quasi-distributed strain-sensing cable (SSC), which has a spatial resolution of 1 m, was developed based on the principle of Identical Weak Fiber Bragg Gratings. The performance of SSC has been evaluated through a series of calibration tests, revealing a range of 0%–3%, an accuracy level of 0.5%, a strain sensitivity measuring at 1.23 pm/ΌΔ, and a temperature sensitivity recorded as 10.78 pm/℃. Furthermore, a real-time deformation monitoring system has been established to monitor rock deformation, consisting of SSC, supporting installation equipment, demodulation equipment, and monitoring software. Moreover, the proposed methodology was applied in the deep roadway of Guqiao coal mine. The results showed that the maximum surface displacement of the roadway is 103.47 mm, while the lateral contrast error stands at 5%. The maximum strain value of the surrounding rock measures 27,095 ΌΔ. The depth of rock rupture zone is about 3 m, while the boundary of rock damage zone extends up to 6 m. This information serves as the foundation for determining the parameters of the roadway reinforcement support design
    • 

    corecore