SKFlow: Learning Optical Flow with Super Kernels

Optical flow estimation is a classical yet challenging task in computer vision. One of the essential factors in accurately predicting optical flow is to alleviate occlusions between frames. However, it is still a thorny problem for current top-performing optical flow estimation methods due to insufficient local evidence to model occluded areas. In this paper, we propose the Super Kernel Flow Network (SKFlow), a CNN architecture to ameliorate the impacts of occlusions on optical flow estimation. SKFlow benefits from the super kernels which bring enlarged receptive fields to complement the absent matching information and recover the occluded motions. We present efficient super kernel designs by utilizing conical connections and hybrid depth-wise convolutions. Extensive experiments demonstrate the effectiveness of SKFlow on multiple benchmarks, especially in the occluded areas. Without pre-trained backbones on ImageNet and with a modest increase in computation, SKFlow achieves compelling performance and ranks $\textbf{1st}$ among currently published methods on the Sintel benchmark. On the challenging Sintel clean and final passes (test), SKFlow surpasses the best-published result in the unmatched areas ($7.96$ and $12.50$) by $9.09\%$ and $7.92\%$. The code is available at \href{https://github.com/littlespray/SKFlow}{https://github.com/littlespray/SKFlow}.Comment: Accepted to NeurIPS 202

StreamFlow: Streamlined Multi-Frame Optical Flow Estimation for Video Sequences

Occlusions between consecutive frames have long posed a significant challenge in optical flow estimation. The inherent ambiguity introduced by occlusions directly violates the brightness constancy constraint and considerably hinders pixel-to-pixel matching. To address this issue, multi-frame optical flow methods leverage adjacent frames to mitigate the local ambiguity. Nevertheless, prior multi-frame methods predominantly adopt recursive flow estimation, resulting in a considerable computational overlap. In contrast, we propose a streamlined in-batch framework that eliminates the need for extensive redundant recursive computations while concurrently developing effective spatio-temporal modeling approaches under in-batch estimation constraints. Specifically, we present a Streamlined In-batch Multi-frame (SIM) pipeline tailored to video input, attaining a similar level of time efficiency to two-frame networks. Furthermore, we introduce an efficient Integrative Spatio-temporal Coherence (ISC) modeling method for effective spatio-temporal modeling during the encoding phase, which introduces no additional parameter overhead. Additionally, we devise a Global Temporal Regressor (GTR) that effectively explores temporal relations during decoding. Benefiting from the efficient SIM pipeline and effective modules, StreamFlow not only excels in terms of performance on the challenging KITTI and Sintel datasets, with particular improvement in occluded areas but also attains a remarkable $63.82\%$ enhancement in speed compared with previous multi-frame methods. The code will be available soon at https://github.com/littlespray/StreamFlow

New advances in clinical application of neostigmine: no longer focusing solely on increasing skeletal muscle strength

Neostigmine is a clinical cholinesterase inhibitor, that is, commonly used to enhance the function of the cholinergic neuromuscular junction. Recent studies have shown that neostigmine regulates the immune-inflammatory response through the cholinergic anti-inflammatory pathway, affecting perioperative neurocognitive function. This article reviews the relevant research evidence over the past 20 years, intending to provide new perspectives and strategies for the clinical application of neostigmine

Tissue engineered corneal epithelium derived from clinical-grade human embryonic stem cells

角膜上皮位于角膜最表层，对维持角膜的透明性发挥非常重要的作用。角膜上皮细胞处于不断更新之中，它们更新的源泉在于角膜缘处的上皮干细胞，即角膜缘干细胞。眼表面化学伤、热烧伤以及部分先天性遗传疾病可以引起角膜缘干细胞缺乏，或者使干细胞丧失向正常角膜上皮细胞分化的能力，导致经久不愈的角膜上皮缺损、角膜新生血管、角膜上皮结膜化、角膜溃疡等病理改变，严重影响患者视力，甚至导致失明。由于眼表面的严重破坏，这类患者的治疗具有很大的挑战性，目前比较理想的治疗方法是进行组织工程角膜上皮移植。 厦门大学眼科研究所和中国科学院动物研究所干细胞与生殖生物学国家重点实验室合作研究采用中科院动物研究所研发的我国第一个临床级胚胎干细胞系Q-CTS-hESC-1，体外诱导分化为角膜上皮祖细胞，在此基础上构建组织工程角膜上皮，移植于兔角膜缘干细胞缺乏动物模型，成功重建眼表面。 厦门大学眼科研究所博士研究生贺佳和欧尚坤为该论文的共同第一作者，厦门大学眼科研究所李炜教授、刘祖国教授以及中科院动物所郝捷副研究员为共同通讯作者。【Abstract】Purpose: To construct tissue engineered corneal epithelium from a clinical-grade human embryonic stem cells (hESCs) and investigate the dynamic gene profile and phenotypic transition in the process of differentiation.Methods: A stepwise protocol was applied to induce differentiation of clinical-grade hESCs Q-CTS-hESC-1 and construct tissue engineered corneal epithelium. Single cell RNA sequencing (scRNA-seq) analysis was performed to monitor gene expression and phenotypic changes at different differentiation stages. Immunostaining, realtime quantitative PCR and Western blot analysis were conducted to detect gene and protein expressions. After subcutaneous transplantation into nude mice to test the biosafety, the epithelial construct was transplanted in a rabbit corneal limbal stem cell deficiency (LSCD) model and followed up for eight weeks. Results: The hESCs were successfully induced into epithelial cells. scRNA-seq analysis revealed upregulation of ocular surface epithelial cell lineage related genes such as TP63, Pax6, KRT14, and activation of Wnt, Notch,Hippo, and Hedgehog signaling pathways during the differentiation process. Tissue engineered epithelial cell sheet derived from hESCs showed stratified structure and normal corneal epithelial phenotype with presence of clonogenic progenitor cells. Eight weeks after grafting the cell sheet onto the ocular surface of LSCD rabbit model, a full-thickness continuous corneal epithelium developed to fully cover the damaged areas with normal limbal and corneal epithelial phenotype. Conclusion: The tissue engineered corneal epithelium generated from a clinical-grade hESCs may be feasible in the treatment of limbal stem cell deficiency.This study was supported in part by the National Key R&D Program of China (2018YFA0107301 [to WL], 2018YFA0107304 [to ZL], 2013CB967003 [to WL]), the National Natural Science Foundation of China (NSFC, No.81770894, No.81470602 [to WL], and No.81330022 [to ZL]). 该论文获得了国家重点研发计划项目和国家自然科学基金项目的资助

NH\u2083 decomposition for H\u2082 production by thermal and plasma catalysis using bimetallic catalysts

Abstract: Plasma catalysis has emerged as a promising approach for driving thermodynamically unfavorable chemical reactions. Nevertheless, comprehending the mechanisms involved remains a challenge, leading to uncertainty about whether the optimal catalyst in plasma catalysis aligns with that in thermal catalysis. In this research, we explore this question by studying monometallic catalysts (Fe, Co, Ni and Mo) and bimetallic catalysts (Fe-Co, Mo-Co, Fe-Ni and Mo-Ni) in both thermal catalytic and plasma catalytic NH3 decomposition. Our findings reveal that the Fe-Co bimetallic catalyst exhibits the highest activity in thermal catalysis, the Fe-Ni bimetallic catalyst outperforms others in plasma catalysis, indicating a discrepancy between the optimal catalysts for the two catalytic modes in NH3 decomposition. Comprehensive catalyst characterization, kinetic analysis, temperature program surface reaction experiments and plasma diagnosis are employed to discuss the key factors influencing NH3 decomposition performance

A Facile Strategy to Enhance the Dielectric and Mechanical Properties of MWCNTs/PVDF Composites with the Aid of MMA-co-GMA Copolymer

A facile strategy is adopted to prepare carboxylic functionalized multiwalled carbon nanotube (c-MWCNT) modified high dielectric constant (high-k) poly(vinylidene fluoride) (PVDF) composites with the aid of methyl methacrylate-co-glycidyl methacrylate copolymer (MG). The MG is miscible with PVDF and the epoxy groups of the copolymer can react with the carboxylic groups of c-MWCNT, which induce the uniform dispersion of c-MWCNT and a form insulator layer on the surface of c-MWCNT. The c-MWCNTs/MG/PVDF composites with 8 vol % c-MWCNT present excellent dielectric properties with high dielectric constant (~448) and low dielectric loss (~2.36) at the frequency of 1 KHz, the dielectric loss is much lower than the c-MWCNT/PVDF composites without MG. The obvious improvement in dielectric properties ascribes to the existence of MG, which impede the direct contact of c-MWCNTs and PVDF and avoid the formation of conductive network. Therefore, we propose a practical and simple strategy for preparing composites with excellent dielectric properties, which are promising for applications in electronics devices

Alexithymia and negative emotions among nursing students: a moderated mediation model

Abstract Nursing students, who comprise a high percentage of China’s college students, experience many psychological problems; however, few studies explored the mechanisms underlying these problems. This cross-sectional study explored the relationships and mechanisms of depression, anxiety, stress, and narrative disorders in senior nursing students. Questionnaires were administered to 380 senior nursing students in Hubei Province using the Sociodemographic Questionnaire, Toronto Alexithymia-20 Scale, Perceived Social Support Scale, 10-Item Connor-Davidson Resilience Scale, and Depression-Anxiety-Stress Scale. After controlling for sociodemographic variables, Hayes’ PROCESS macros were used to test how psychological resilience moderates the relationships among narrative disorders, negative affect, and perceived social support. Bootstrap confidence intervals tested for indirect effects. Correlation analyses revealed that alexithymia was correlated significantly positively with depression-anxiety-stress (r = 0.57, 0.56, and 0.58, resp.) and significantly negatively with perceived social support (r = 0-0.46). Psychological resilience was correlated significantly negatively with alexithymia (r=-0.39) and depression-anxiety-stress (r=-0.31, -0.30, and-0.32, resp.) but significantly positively with perceived social support(r = 0.50). Perceived social support was correlated significantly negatively with depression-anxiety-stress (r=-0.33, -0.34, and − 0.42 resp.). Stress was correlated significantly positively with anxiety and depression (r = 0.81 and 0.77, resp.). Psychological resilience was a partial mediator between depression and dysphoria (β=-0.08, p < 0.05). Dysphoria directly predicted anxiety (β = 0.31) and stress (β = 0.37); moreover,alexithymia predicted depression not only directly but also through the mediating effect of psychological resilience. Therefore, educators and clinical administrators must promote and recognise negative emotions among nursing students to help ensure the nursing workforce’s stability

Plasma-assisted dry reforming of CH\u2084 : how small amounts of O\u2082 addition can drastically enhance the oxygenate production\u2500experiments and insights from plasma chemical kinetics modeling

Abstract: Plasma-based dry reforming of methane (DRM) into high-value-added oxygenates is an appealing approach to enable otherwise thermodynamically unfavorable chemical reactions at ambient pressure and near room temperature. However, it suffers from coke deposition due to the deep decomposition of CH4. In this work, we assess the DRM performance upon O2 addition, as well as varying temperature, CO2/CH4 ratio, discharge power, and gas residence time, for optimizing oxygenate production. By adding O2, the main products can be shifted from syngas (CO + H2) toward oxygenates. Chemical kinetics modeling shows that the improved oxygenate production is due to the increased concentration of oxygen-containing radicals, e.g., O, OH, and HO2, formed by electron impact dissociation [e + O2 \u2192 e + O + O/O(1D)] and subsequent reactions with H atoms. Our study reveals the crucial role of oxygen-coupling in DRM aimed at oxygenates, providing practical solutions to suppress carbon deposition and at the same time enhance the oxygenates production in plasma-assisted DRM