60 research outputs found

    CSI-PPPNet: A One-Sided One-for-All Deep Learning Framework for Massive MIMO CSI Feedback

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    To reduce multiuser interference and maximize the spectrum efficiency in orthogonal frequency division duplexing massive multiple-input multiple-output (MIMO) systems, the downlink channel state information (CSI) estimated at the user equipment (UE) is required at the base station (BS). This paper presents a novel method for massive MIMO CSI feedback via a one-sided one-for-all deep learning framework. The CSI is compressed via linear projections at the UE, and is recovered at the BS using deep learning (DL) with plug-and-play priors (PPP). Instead of using handcrafted regularizers for the wireless channel responses, the proposed approach, namely CSI-PPPNet, exploits a DL based denoisor in place of the proximal operator of the prior in an alternating optimization scheme. In this way, a DL model trained once for denoising can be repurposed for CSI recovery tasks with arbitrary compression ratio. The one-sided one-for-all framework reduces model storage space, relieves the burden of joint model training and model delivery, and could be applied at UEs with limited device memories and computation power. Extensive experiments over the open indoor and urban macro scenarios show the effectiveness and advantages of the proposed method

    Dissociation of neural substrates of response inhibition to negative information between implicit and explicit facial go/nogo tasks: evidence from an electrophysiological study

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    Creative Commons Attribution LicenseBackground: Although ample evidence suggests that emotion and response inhibition are interrelated at the behavioral and neural levels, neural substrates of response inhibition to negative facial information remain unclear. Thus we used event-related potential (ERP) methods to explore the effects of explicit and implicit facial expression processing in response inhibition. Methods: We used implicit (gender categorization) and explicit emotional Go/Nogo tasks (emotion categorization) in which neutral and sad faces were presented. Electrophysiological markers at the scalp and the voxel level were analyzed during the two tasks. Results: We detected a task, emotion and trial type interaction effect in the Nogo-P3 stage. Larger Nogo-P3 amplitudes during sad conditions versus neutral conditions were detected with explicit tasks. However, the amplitude differences between the two conditions were not significant for implicit tasks. Source analyses on P3 component revealed that right inferior frontal junction (rIFJ) was involved during this stage. The current source density (CSD) of rIFJ was higher with sad conditions compared to neutral conditions for explicit tasks, rather than for implicit tasks. Conclusions: The findings indicated that response inhibition was modulated by sad facial information at the action inhibition stage when facial expressions were processed explicitly rather than implicitly. The rIFJ may be a key brain region in emotion regulation.This research was supported by the National Natural Science Foundation of China (31000503, 91232717, 31100812, 81301176, and 81300944) and the Ministry of Science and Technology (2011CB707805)

    E2F1 Suppresses Oxidative Metabolism and Endothelial Differentiation of Bone Marrow Progenitor Cells

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    RATIONALE: The majority of current cardiovascular cell therapy trials use bone marrow progenitor cells (BM PCs) and achieve only modest efficacy; the limited potential of these cells to differentiate into endothelial-lineage cells is one of the major barriers to the success of this promising therapy. We have previously reported that the E2F transcription factor 1 (E2F1) is a repressor of revascularization after ischemic injury. OBJECTIVE: We sought to define the role of E2F1 in the regulation of BM PC function. METHODS AND RESULTS: Ablation of E2F1 (E2F1 deficient) in mouse BM PCs increases oxidative metabolism and reduces lactate production, resulting in enhanced endothelial differentiation. The metabolic switch in E2F1-deficient BM PCs is mediated by a reduction in the expression of pyruvate dehydrogenase kinase 4 and pyruvate dehydrogenase kinase 2; overexpression of pyruvate dehydrogenase kinase 4 reverses the enhancement of oxidative metabolism and endothelial differentiation. Deletion of E2F1 in the BM increases the amount of PC-derived endothelial cells in the ischemic myocardium, enhances vascular growth, reduces infarct size, and improves cardiac function after myocardial infarction. CONCLUSION: Our results suggest a novel mechanism by which E2F1 mediates the metabolic control of BM PC differentiation, and strategies that inhibit E2F1 or enhance oxidative metabolism in BM PCs may improve the effectiveness of cell therapy

    Dissociable Early Attentional Control Mechanisms Underlying Cognitive and Affective Conflicts

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    It has been well documented that cognitive conflict is sensitive to the relative proportion of congruent and incongruent trials. However, few studies have examined whether affective conflict processing is modulated as a function of proportion congruency (PC). To address this question we recorded eventrelated potentials (ERP) while subjects performed both cognitive and affective face-word Stroop tasks. By varying the proportion of congruent and incongruent trials in each block, we examined the extent to which PC impacts both cognitive and affective conflict control at different temporal stages. Results showed that in the cognitive task an anteriorly localized early N2 component occurred predominantly in the low proportion congruency context, whereas in the affective task it was found to occur in the high proportion congruency one. The N2 effects across the two tasks were localized to the dorsolateral prefrontal cortex, where responses were increased in the cognitive task but decreased in the affective one. Furthermore, high proportions of congruent items produced both larger amplitude of a posteriorly localized sustained potential component and a larger behavioral Stroop effect in cognitive and affective tasks. Our findings suggest that cognitive and affective conflicts engage early dissociable attentional control mechanisms and a later common conflict response system

    Proposed clinical phases for the improvement of personalized treatment of checkpoint inhibitorā€“related pneumonitis

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    BackgroundCheckpoint inhibitorā€“related pneumonitis (CIP) is a lethal immune-related adverse event. However, the development process of CIP, which may provide insight into more effective management, has not been extensively examined.MethodsWe conducted a multicenter retrospective analysis of 56 patients who developed CIP. Clinical characteristics, radiological features, histologic features, and laboratory tests were analyzed. After a comprehensive analysis, we proposed acute, subacute, and chronic phases of CIP and summarized each phaseā€™s characteristics.ResultsThere were 51 patients in the acute phase, 22 in the subacute phase, and 11 in the chronic phase. The median interval time from the beginning of CIP to the different phases was calculated (acute phase: ā‰¤4.9 weeks; subacute phase: 4.9~13.1 weeks; and chronic phase: ā‰„13.1 weeks). The symptoms relieved from the acute phase to the chronic phase, and the CIP grade and Performance Status score decreased (P<0.05). The main change in radiologic features was the absorption of the lesions, and 3 (3/11) patients in the chronic phase had persistent traction bronchiectasis. For histologic features, most patients had acute fibrinous pneumonitis in the acute phase (5/8), and most had organizing pneumonia in the subacute phase (5/6). Other histologic changes advanced over time, with the lesions entering a state of fibrosis. Moreover, the levels of interleukin-6, interleukin-10 and high-sensitivity C-reactive protein (hsCRP) increased in the acute phase and decreased as CIP progressed (IL-6: 17.9 vs. 9.8 vs. 5.7, P=0.018; IL-10: 4.6 vs 3.0 vs. 2.0, P=0.041; hsCRP: 88.2 vs. 19.4 vs. 14.4, P=0.005).ConclusionsThe general development process of CIP can be divided into acute, subacute, and chronic phases, upon which a better management strategy might be based devised

    Investigation on the Gas Drainage Effectiveness from Coal Seams by Parallel Boreholes

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    Gas drainage is an important technology to prevent coal and gas outburst, and the drained gas is a kind of clean energy. The gas pressure can characterize gas drainage effectiveness. In this paper, we investigated the effectiveness of gas drainage by gas pressure. Determined by the space shape of the gas flow field, the gas flow state surrounding the drainage boreholes is radial flow. According to the basic equations of radial flow, discrete equations were achieved by the implicit difference scheme, and then we obtained the gas pressure surrounding the drainage boreholes. Results showed that the midpoint between two holes presents the highest gas pressure, and gas pressure declined from the midpoint of two boreholes to both sides. The midpoint gas pressure of the two holes reflects gas drainage effectiveness in a certain degree. Gas pressure declined with segmented characteristics in the first period decline curve in the form of a cubic curve, and the second period decline curve in the form of a straight line. When the drainage pressure reaches a certain value, the decline rate of gas pressure had little relationship with the drainage negative pressure, mainly influenced by the permeability coefficient. To improve the drainage effectiveness, anti-reflection measures are feasible, instead of increasing the drainage negative pressure. Moreover, the conclusion was verified by field data

    Study on healthcare level and its relationship with medical radiation in China

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    Objective: To evaluate the health-care level (HCL), one of the most extensively used indicators to assess the level of medical exposure, and its influencing factors in China. Methods: Based on the data from the China Statistical Yearbook of the National Bureau of Statistics and other public documents, HCL was calculated in terms of the number of physicians per head of population throughout the country. Multiple linear regression was used to analyze the association of HCL with main socioeconomic factors, including population size, area, number of administrative divisions and gross domestic product (GDP). Results: Since 2015, there has been at least one physician for every 1,000 people in China on average. However, by 2019, there has yet been one physician for more than 1,000 people in each of two provinces. By 2020, there was at least one physician for every 1,000 people across all 31 provincial-level administrative districts (provinces). The population size and GDP were the influencing factors on HCL, with correlation coefficients of 0.416 and āˆ’0.583, respectively. Furthermore, a moderate correlation was found between HCL and the frequency of medical exposure (FME) to ionizing radiation (rĀ ā€‹=Ā ā€‹āˆ’0.620, PĀ ā€‹=Ā ā€‹0.028). Conclusion: There has been at least one physician for every 1,000 people since 2015, but there are great differences between various provinces. HCL as an indicator to evaluate level of medical exposure is warranted further research in China
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