198 research outputs found

    Effective Room-Temperature Ammonia-Sensitive Composite Sensor Based on Graphene Nanoplates and PANI

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    The graphene nanoplate (GN)-polyaniline (PANI) composite was developed via in-situ polymerization method and simultaneously assembled on interdigital electrodes (IDEs) at low temperature for ammonia (NH3) detection. The assembled composite sensor showed excellent sensing performance toward different concentrations of NH3, 1.5 of response value and 123 s/204 s for the response/recovery time to 15 ppm NH3. Meanwhile, an interesting supersaturation phenomenon was observed at high concentration of NH3. A reasonable speculation was proposed for this special sensing behavior and the mechanism for enhanced sensing properties was also analyzed

    Tradeoff Caching Strategy of Outage Probability and Fronthaul Usage in Cloud-RAN

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    In this paper, tradeoff content caching strategy is proposed to jointly minimize the cell average outage probability and fronthaul usage in cloud radio access network (Cloud-RAN). At first, an accurate closed form expression of the outage probability conditioned on the user’s location is presented, and the cell average outage probability is obtained through the composite Simpson’s integration. The caching strategy for jointly optimizing the cell average outage probability and fronthaul usage is then formulated as a weighted sum minimization problem, which is a nonlinear 0-1 integer problem. Two heuristic algorithms are proposed to solve the problem. Firstly, a genetic algorithm (GA) based approach is proposed. Numerical results show that the performance of the proposed GA-based approach with significantly reduced computational complexity is close to the optimal performance achieved by exhaustive search based caching strategy, and the GA-based approach can improve the performance by up to 47.5% on average than the typical probabilistic caching strategy. Secondly, in order to further reduce the computational complexity, a mode selection approach is proposed. Numerical results show that this approach can achieve near-optimal performance over a wide range of the weighting factors through a single computation

    Outage Probability and Fronthaul Usage Tradeoff Caching Strategy in Cloud-RAN

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    In this paper, optimal content caching strategy is proposed to jointly minimize the cell average outage probability and fronthaul usage in cloud radio access network (Cloud-RAN). An accurate closed form expression of the outage probability conditioned on the user’s location is presented, and the cell average outage probability is obtained through the composite Simpson’s integration. The caching strategy for jointly optimizing the cell average outage probability and fronthaul usage is formulated as a weighted sum minimization problem, which is a nonlinear 0-1 integer NP-hard problem. In order to deal with the NP-hard problem, at first, two particular caching placement schemes are investigated: the most popular content (MPC) caching scheme and the proposed location-based largest content diversity (LB-LCD) caching scheme. Then a genetic algorithm (GA) based approach is proposed. Numerical results show that the performance of the proposed GA-based approach with significantly reduced computational complexity is close to the optimal performance achieved by exhaustive search based caching strategy

    SurrealDriver: Designing Generative Driver Agent Simulation Framework in Urban Contexts based on Large Language Model

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    Simulation plays a critical role in the research and development of autonomous driving and intelligent transportation systems. However, the current simulation platforms exhibit limitations in the realism and diversity of agent behaviors, which impede the transfer of simulation outcomes to the real world. In this paper, we propose a generative driver agent simulation framework based on large language models (LLMs), capable of perceiving complex traffic scenarios and providing realistic driving maneuvers. Notably, we conducted interviews with 24 drivers and used their detailed descriptions of driving behavior as chain-of-thought prompts to develop a `coach agent' module, which can evaluate and assist driver agents in accumulating driving experience and developing human-like driving styles. Through practical simulation experiments and user experiments, we validate the feasibility of this framework in generating reliable driver agents and analyze the roles of each module. The results show that the framework with full architect decreased the collision rate by 81.04% and increased the human-likeness by 50%. Our research proposes the first urban context driver agent simulation framework based on LLMs and provides valuable insights into the future of agent simulation for complex tasks.Comment: 12 pages, 8 figure

    Removal of Formaldehyde Using Highly Active Pt/TiO 2

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    Formaldehyde (HCHO) is one of the major indoor air pollutants. TiO2 supported Pt catalysts were prepared by sol-gel method and used to eliminate HCHO at room temperature without irradiation. The reduced Pt/TiO2 catalyst (denoted as Pt/TiO2-H2) showed much higher activity than that calcined in air (denoted as Pt/TiO2-air). More than 96% of the conversion of HCHO was obtained over 0.5 wt% Pt/TiO2-H2, on which highly dispersed metallic Pt nanoparticles with very small size (~2 nm) were identified. Metallic Pt rather than cationic Pt nanoparticles provide the active sites for HCHO oxidation. Negatively charged metallic Pt nanoparticles facilitate the transfer of charge and oxygen species and the activation of oxygen

    An Efficient Virus-Induced Gene Silencing System for Functional Genomics Research in Walnut (Juglans regia L.) Fruits

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    The Persian walnut (Juglans regia L.) is a leading source of woody oil in warm temperate regions and has high nutritional and medicinal values. It also provides both tree nuts and woody products. Nevertheless, incomplete characterization of the walnut genetic system limits the walnut gene function analysis. This study used the tobacco rattle virus (TRV) vector to construct an infectious pTRV-JrPDS recombinant clone. A co-culture inoculation method utilizing Agrobacterium was screened out from four inoculation methods and optimized to set up an efficient virus-induced gene silencing (VIGS) system for J. regia fruit. The optimized VIGS-TRV system induced complete photobleaching phenotype on the walnut fruits of four cultivars, and the JrPDS transcript levels decreased by up to 88% at 8 days post-inoculation (dpi). While those of browning-related J. regia polyphenol oxidase (PPO) genes JrPPO1 and JrPPO2 decreased by 67 and 80% at 8 dpi, respectively, accompanied by a significant reduction in fruit browning phenotype. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis screening and Western Blot showed that the PPO protein levels were significantly reduced. Moreover, a model of TRV-mediated VIGS system for inoculating J. regia fruit with efficient silence efficiency via co-culture was developed. These results indicate that the VIGS-TRV system is an efficient tool for rapid gene function analysis in J. regia fruits

    Evaluation of the impact of the COVID-19 pandemic on health service utilization in China: A study using auto-regressive integrated moving average model

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    BackgroundThe outbreak of COVID-19 in early 2020 presented a major challenge to the healthcare system in China. This study aimed to quantitatively evaluate the impact of COVID-19 on health services utilization in China in 2020.MethodsHealth service-related data for this study were extracted from the China Health Statistical Yearbook. The Auto-Regressive Integrated Moving Average model (ARIMA) was used to forecast the data for the year 2020 based on trends observed between 2010 and 2019. The differences between the actual 2020 values reported in the statistical yearbook and the forecast values from the ARIMA model were used to assess the impact of COVID-19 on health services utilization.ResultsIn 2020, the number of admissions and outpatient visits in China declined by 17.74 and 14.37%, respectively, compared to the ARIMA model’s forecast values. Notably, public hospitals experienced the largest decrease in outpatient visits and admissions, of 18.55 and 19.64%, respectively. Among all departments, the pediatrics department had the greatest decrease in outpatient visits (35.15%). Regarding geographical distribution, Beijing and Heilongjiang were the regions most affected by the decline in outpatient visits (29.96%) and admissions (43.20%) respectively.ConclusionThe study’s findings suggest that during the first year of the COVID-19 pandemic, one in seven outpatient services and one in six admissions were affected in China. Therefore, there is an urgent need to establish a green channel for seeking medical treatment without spatial and institutional barriers during epidemic prevention and control periods

    Bearing surface defect detection based on improved convolutional neural network

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    This paper addresses the issue of artificial visual inspection being overly reliant on subjective experience and the difficulty for the human eye to accurately identify dense and non-significant defects. To solve this problem, we have implemented an automatic object detection algorithm based on an improved version of YOLOv5.First, we use the K-means++ clustering algorithm to automatically calculate the Anchor of the model to reduce the effect of the close location of the initial clustering centers on the clustering of the sample data.Second, we add the Coordinate Attention (CA) attention mechanism to the model to allow the model to better capture and understand important features in the images. Then, we add a new detection layer with a downsampling multiplier of 4 to the Neck network to improve the precision of the model. Finally, we use the lightweight network MobileNetV3 instead of YOLOv5's backbone network to reduce the model detection time overhead.Our model achieves 85.87% mAP, which is 6.44% better than the YOLOv5 network, and the detection time for a single image is only 54ms, which is 50% faster than the YOLOv5 network. After testing, we have proven that our proposed algorithm can quickly and accurately detect the condition of bearing appearance defects, improving detection efficiency and reducing costs

    Influence of different caregiving styles on fundamental movement skills among children

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    PurposeThis study investigated the influence of parenting and grandparenting caregiving styles on fundamental motor skills (FMS) of preschool children.MethodA total of 1,326 preschool children (698 boys, 628 girls) aged 4–6 years were recruited from the kindergartens of Jinhua City, China. Locomotor skills (LM), ball skills (BS), and total fundamental movement skills (TS) of children were assessed by the Test of Gross Motor Development-3rd edition (TGMD-3).ResultsThere were 978 children in parenting and 348 children in grandparenting caregiving styles. The LM, BS and TS scores of children were considerably (p < 0.001) increased with age (irrespective of sex or caregiving style). For the sex comparisons, BS scores of boys were significantly higher than girls (p < 0.001), while LM and TS scores were not different between boys and girls. For the caregiving style comparison, parenting is superior to grandparenting in developing of children's FMS. Parenting boys of 4-, 5-, and 6-years old showed better BS compared to age-matched parenting girls, whereas boys of 5-years old in grandparenting only showed better BS compared to same-age grandparenting girls (p < 0.05). Furthermore, parenting boys of 6-years reported higher LM (p < 0.01), BS (p < 0.001), and TS (p < 0.001) scores compared to grandparenting boys, but girls' FMS at all ages were not significantly different between the caregiving styles.ConclusionParenting caregiving style is positively associated with proper development of FMS among children. Girl children with poor FMS in grandparenting may need a special care or intervention programs to promote their FMS

    Axin determines cell fate by controlling the p53 activation threshold after DNA damage

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    Cells can undergo either cell-cycle arrest or apoptosis after genotoxic stress, based on p53 activity(1-6). Here we show that cellular fate commitment depends on Axin forming distinct complexes with Pirh2, Tip60, HIPK2 and p53. In cells treated with sublethal doses of ultra-violet (UV) radiation or doxorubicin (Dox), Pirh2 abrogates Axin-induced p53 phosphorylation at Ser 46 catalysed by HIPK2, by competing with HIPK2 for binding to Axin. However, on lethal treatment, Tip60 interacts with Axin and abrogates Pirh2-Axin binding, forming an Axin-Tip60-HIPK2-p53 complex that allows maximal p53 activation to trigger apoptosis. We also provide evidence that the ATM/ATR pathway mediates the Axin-Tip60 complex assembly. An axin mutation promotes carcinogenesis in Axin(Fu)/+ (Axin-Fused) mice, consistent with a dominant-negative role for Axin(Fu) in p53 activation. Thus, Axin is a critical determinant in p53-dependent tumour suppression in which Pirh2 and Tip60 have different roles in triggering cell-cycle arrest or apoptosis depending on the severity of genotoxic stress.973 Program and 863 Program National Natural Science Foundation of China Ministry of Education of China National Basic Research Program of the Ministry of Science and Technology National Science Foundation of Fujian Provinc
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