Enormous efforts have been devoted to the reduction of carbon dioxide (CO2) by utilizing various driving forces, such as heat, electricity, and radiation. However, the efficient reduction of CO2 is ...still challenging because of sluggish kinetics. Recent pioneering studies from several groups, including us, have demonstrated that the coupling of solar energy and thermal energy offers a novel and promising strategy to promote the activity and/or manipulate selectivity in CO2 reduction. Herein, we clarify the definition and principles of coupling solar energy and thermal energy, and comprehensively review the status and prospects of CO2 reduction by coupling solar energy and thermal energy. Catalyst design, reactor configuration, photo‐mediated activity/selectivity, and mechanism studies in photo‐thermo CO2 reduction will be emphasized. The aim of this Review is to promote understanding towards CO2 activation and provide guidelines for the design of new catalysts for the efficient reduction of CO2.
A bundle of energy: The coupling of solar energy and thermal energy is a promising strategy to mediate the activity and/or selectivity of CO2 reduction. The status and prospects of this topic are reviewed, with the aim of providing guidelines for the design of new catalysts.
A convolutional neural network (CNN) is one of the most significant networks in the deep learning field. Since CNN made impressive achievements in many areas, including but not limited to computer ...vision and natural language processing, it attracted much attention from both industry and academia in the past few years. The existing reviews mainly focus on CNN's applications in different scenarios without considering CNN from a general perspective, and some novel ideas proposed recently are not covered. In this review, we aim to provide some novel ideas and prospects in this fast-growing field. Besides, not only 2-D convolution but also 1-D and multidimensional ones are involved. First, this review introduces the history of CNN. Second, we provide an overview of various convolutions. Third, some classic and advanced CNN models are introduced; especially those key points making them reach state-of-the-art results. Fourth, through experimental analysis, we draw some conclusions and provide several rules of thumb for functions and hyperparameter selection. Fifth, the applications of 1-D, 2-D, and multidimensional convolution are covered. Finally, some open issues and promising directions for CNN are discussed as guidelines for future work.
Background and Aims
There is growing evidence that single‐stranded, circular RNA (circRNA) plays a key role in the development of certain cancers, including hepatocellular carcinoma (HCC). It is less ...clear, however, what role circRNA plays in HCC metastasis.
Approach and Results
In this study, through circRNA sequencing, we identified a circRNA: circASAP1 (a circRNA derived from exons 2 and 3 of the ASAP1 gene, hsa_circ_0085616), which is associated with pulmonary metastasis after curative resection in patients with HCC. CircASAP1 was overexpressed in HCC cell lines with high metastatic potential and in metastatic HCCs. In vitro, circASAP1 promoted cell proliferation, colony formation, migration, and invasion, and in vivo, it enhanced tumor growth and pulmonary metastasis. Mechanism studies showed that circASAP1 acts as a competing endogenous RNA for microRNA 326 (miR‐326) and microRNA 532‐5p (miR‐532‐5p), both of which are tumor suppressors in HCC. We found that mitogen‐activated protein kinase (MAPK) 1 and colony stimulating factor (CSF)‐1 were direct common targets for microRNA 326 (miR‐326) and microRNA 532‐5p (miR‐532‐5p), which were regulated by circASAP1. CircASAP1 promotes HCC cell proliferation and invasion by regulating miR‐326/miR‐532‐5p‐MAPK1 signaling and, furthermore, mediates tumor‐associated macrophage infiltration by regulating the miR‐326/miR‐532‐5p‐CSF‐1 pathway. Clinical HCC samples exhibited a positive correlation between circASAP1 expression and levels of CSF‐1, MAPK1, and CD68+ tumor‐associated macrophages, all of which were predictive of patient outcomes.
Conclusion
We identified circASAP1 as a key regulator of HCC metastasis that acts on miR‐326/miR‐532‐5p‐MAPK1/CSF‐1 signaling and serves as a prognostic predictor in patients with HCC.
Tumor‐associated neutrophils (TANs) play a crucial role in tumor development and progression in the cancer microenvironment. Despite increased understanding of TAN contributions to hepatocellular ...carcinoma (HCC) progression and prognosis, the direct interaction between TANs and HCC cells is not fully understood. In this study, we tested the effect of TANs on HCC cells in vitro and in vivo and investigated the mechanism of interaction between them. Our results showed that TANs secreted bone morphogenetic protein 2 and transforming growth factor beta 2 and triggered microRNA 301b‐3p (miR‐301‐3p) expression in HCC cells, subsequently suppressed gene expression of limbic system–associated membrane protein (LSAMP) and CYLD lysine 63 deubiquitinase (CYLD), and increased stem cell characteristics in HCC cells. These TAN‐induced HCC stem‐like cells were hyperactive in nuclear factor kappa B signaling, secreted higher levels of chemokine (C‐X‐C motif) ligand 5 (CXCL5), and recruited more TAN infiltration, suggesting a positive feedback loop. In clinical HCC samples, increased TANs correlated with elevated miR‐301b‐3p, decreased LSAMP and CYLD expression, and increased nuclear p65 accumulation and CXCL5 expression, all of which predicted patient outcome. Conclusion: Our work identified a positive feedback loop governing cancer stem‐like cells and TANs in HCC that controls tumor progression and patient outcome.
The demand for flexible conductive materials has motivated many recent studies on conductive polymer–based materials. However, the thermal conductivity of conductive polymers is relatively low, which ...may lead to serious heat dissipation problems for device applications. This review provides a summary of the fundamental principles for thermal transport in conductive polymers and their composites, and recent advancements in regulating their thermal conductivity. The thermal transport mechanisms in conductive polymer–based materials and up‐to‐date experimental approaches for measuring thermal conductivity are first summarized. Effective approaches for the regulation of thermal conductivity are then discussed. Finally, thermal‐related applications and future perspectives are given for conductive polymers and their composites.
Conductive polymer–based materials can offer novel applications such as flexible electronics and wearable biosensors. However, their intrinsically low thermal conductivity limits their applications. This review provides a summary of the fundamental principles for thermal transport in conductive polymers and their composites, recent advancements in regulating their thermal conductivity, and their thermal‐related applications.
•Pulmonary CT features of the 2019 novel coronavirus disease were diverse.•This disease changed rapidly at the early stage, and lasted for a long time.•CT could provide semi-quantitative analysis of ...pulmonary damage severity.
To evaluate lung abnormalities on thin-section computed tomographic (CT) scans in patients with COVID-19 and correlate findings to duration of symptoms.
In total, 348 CT scans in 112 patients were classified according to the time after the onset of the initial symptoms, namely stage-1 (0–4 days); stage-2 (5–9 days); stage-3 (10–14 days); stage-4 (15–21 days); stage-5 (22–28 days); and stage-6 (＞28 days). Each lung lobe was evaluated for extent affected by ground-glass opacities (GGO), crazy-paving pattern and consolidation, in five categories of percentual severity. Summation of scores from all five lung lobes provided the total CT score (maximal CT score, 25).
The predominant patterns of lung abnormalities were GGOs, crazy-paving pattern, consolidation and linear opacities. The frequency of crazy-paving pattern, consolidation and linear opacities peaked at stage-3 (62.7 %), stage-4 (75.0 %) and stage-5 (83.1 %), respectively, and decreased thereafter. Total CT scores increased from stage-1 to stage-2 (2.8 ± 3.1, vs. 6.5 ± 4.6, respectively, P < 0.01), and thereafter remained high. The lower lobes were more inclined to be involved with higher CT scores except for stage-1. At stage-6 98.1 % of CT scans still showed abnormalities (CT score 7.5 ± 4.1).
Thin-section CT could provide semi-quantitative analysis of pulmonary damage severity. This disease changed rapidly at the early stage, then tended to be stable and lasted for a long time.
MicroRNAs (miRNAs) play a critical role in regulation of tumor metastasis. However, the role of these molecules in hepatocellular carcinoma (HCC) has not been fully elucidated. In this study, we ...employed miRNA‐sequencing and identified 22 miRNAs involved in HCC metastasis. One of these, miR‐28‐5p, was down‐regulated in HCCs. This down‐regulation correlated with tumor metastasis, recurrence, and poor survival. Biofunctional investigations revealed that miR‐28‐5p deficiency promoted tumor growth and metastasis in nude mice without altering the in vitro biological characteristics of HCC cells. Through gene expression profiles and bioinformatics analysis, we identified interleukin‐34 (IL‐34) as a direct target of miR‐28‐5p, and the effects of miR‐28‐5p deficiency on HCC growth and metastasis was dependent on IL‐34‐mediated tumor‐associated macrophage (TAM) infiltration. Moreover, we found that TAMs induced by miR‐28‐5p‐IL‐34 signaling inhibit miR‐28‐5p expression on HCC cells by transforming growth factor beta 1, resulting in an miR‐28‐5p‐IL‐34‐macrophage‐positive feedback loop. In clinical HCC samples, miR‐28‐5p levels were inversely correlated with IL‐34 expression and the number of TAMs. Patients with low miR‐28‐5p expression, high IL‐34 levels, and high numbers of TAMs had a poor prognosis with shorter overall survival and time to recurrence. Conclusion: A miR‐28‐5p‐IL‐34‐macrophage feedback loop modulates HCC metastasis and serves as a novel prognostic factor as well as a therapeutic target for HCC. (Hepatology 2016;63:1560‐1575)
Following the rapid development of lightweight and flexible smart electronic products, providing energy for these electronics has become a hot research topic. The human body produces considerable ...mechanical and thermal energy during daily activities, which could be used to power most wearable electronics. In this context, fiber‐based energy conversion devices (FBECD) are proposed as candidates for effective conversion of human‐body energy into electricity for powering wearable electronics. Herein, functional materials, fiber fabrication techniques, and device design strategies for different classes of FBECD based on piezoelectricity, triboelectricity, electrostaticity, and thermoelectricity are comprehensively reviewed. An overview of fiber‐based self‐powered systems and sensors according to their superior flexibility and cost‐effectiveness is also presented. Finally, the challenges and opportunities in the field of fiber‐based energy conversion are discussed.
Fiber‐shaped energy‐conversion devices can directly harvest mechanical or thermal energy from the human body, and convert it into electric energy. These nanogenerators can supply power for wearable electronics and act as self‐powered sensors to monitor human health signals.
Iron‐based heterogeneous catalysts, which were generally prepared by pyrolysis of iron complexes on supports at elevated temperature, were found to be capable of catalyzing the transfer hydrogenation ...of furfural (FF) to furfuryl alcohol (FFA). The effects of metal precursor, nitrogen precursor, pyrolysis temperature, and support on catalytic performance were examined thoroughly, and a comprehensive study of the reaction parameters was also performed. The highest selectivity of FFA reached 83.0 % with a FF conversion of 91.6 % under the optimal reaction condition. Catalyst characterization suggested that iron cations coordinated by pyridinic nitrogen functionalities were responsible for the enhanced catalytic activity. The iron catalyst could be recycled without significant loss of catalytic activity for five runs, and the destruction of the nitrogen–iron species, the presence of crystallized Fe2O3 phase, and the pore structure change were the main reasons for catalyst deactivation.
FF to FFA with Fe: Efficient catalytic transfer hydrogenation of furfural (FF) to furfuryl alcohol (FFA) over heterogeneous iron catalysts is demonstrated for the first time. Iron cations coordinated by pyridinic nitrogen functionalities on the carbon support are possibly responsible for the enhanced catalytic activity. This paves the way for achieving biomass conversion through heterogeneous iron catalysis.
Traditional color images only depict color intensities in red, green and blue channels, often making object trackers fail in challenging scenarios, e.g., background clutter and rapid changes of ...target appearance. Alternatively, material information of targets contained in large amount of bands of hyperspectral images (HSI) is more robust to these difficult conditions. In this paper, we conduct a comprehensive study on how material information can be utilized to boost object tracking from three aspects: dataset, material feature representation and material based tracking. In terms of dataset, we construct a dataset of fully-annotated videos, which contain both hyperspectral and color sequences of the same scene. Material information is represented by spectral-spatial histogram of multidimensional gradients, which describes the 3D local spectral-spatial structure in an HSI, and fractional abundances of constituted material components which encode the underlying material distribution. These two types of features are embedded into correlation filters, yielding material based tracking. Experimental results on the collected dataset show the potentials and advantages of material based object tracking.
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