Towards Practical Capture of High-Fidelity Relightable Avatars

In this paper, we propose a novel framework, Tracking-free Relightable Avatar (TRAvatar), for capturing and reconstructing high-fidelity 3D avatars. Compared to previous methods, TRAvatar works in a more practical and efficient setting. Specifically, TRAvatar is trained with dynamic image sequences captured in a Light Stage under varying lighting conditions, enabling realistic relighting and real-time animation for avatars in diverse scenes. Additionally, TRAvatar allows for tracking-free avatar capture and obviates the need for accurate surface tracking under varying illumination conditions. Our contributions are two-fold: First, we propose a novel network architecture that explicitly builds on and ensures the satisfaction of the linear nature of lighting. Trained on simple group light captures, TRAvatar can predict the appearance in real-time with a single forward pass, achieving high-quality relighting effects under illuminations of arbitrary environment maps. Second, we jointly optimize the facial geometry and relightable appearance from scratch based on image sequences, where the tracking is implicitly learned. This tracking-free approach brings robustness for establishing temporal correspondences between frames under different lighting conditions. Extensive qualitative and quantitative experiments demonstrate that our framework achieves superior performance for photorealistic avatar animation and relighting.Comment: Accepted to SIGGRAPH Asia 2023 (Conference); Project page: https://travatar-paper.github.io

Comparison and research on load characteristics of PM in different permanent magnet synchronous machines

PM enable PMSMs to have higher torque-density and power-density, however the machine performance is closely related to its load characteristics. When the armature excitation does not match the load characteristics of the PM and machine, it can lead to demagnetization and performance degradation. By comparing and studying the IPMSM’s and SPMSM’s load characteristics, a more reasonable machine topology of components such as PM can be obtained, and high-performance machines can be designed more efficiently. Based on the material characteristics of the PM, the armature reaction law of different machines and the demagnetization law of the PM at different current angles were analyzed. There are different magnetic field distribution patterns in IPMSM and SPMSM, and their different load characteristics are compared to study the methods for improving the anti-demagnetization ability of PMs based on different machine structures

Interfacial Structure and Transformation of Guanine-Rich Oligonucleotides on Solid Supported Lipid Bilayer Investigated by Sum Frequency Generation Vibrational Spectroscopy

Lipid membrane-anchored guanine-rich oligonucleotides with non-Watson–Crick structures can perform structure transformation in a controllable and reversible manner upon the external stimuli. Elucidating the mechanisms of their interaction and transformation is the key to understand medical applicability and functioning feasibility of these oligonucleotides. In this study, the molecular structure and interfacial transformation kinetics of guanine-rich oligonucleotides at model cell membrane were investigated by sum frequency generation vibrational spectroscopy (SFG-VS) in real time and <i>in situ</i>. The conformations of oligonucleotides are obtained by analyzing the SFG spectra in the “fingerprint” region. The results indicate that the electrostatic interaction and hydrophobic interaction are both important to the interfacial adsorption and transformation of oligonucleotides. The tilt angles of oligonucleotides with different conformations were also calculated. Molecular insights into interfacial oligonucleotides will help researchers to control the oligonucleotide–lipid membrane interactions in a desired manner and improve the reproductivity, stability, and reversibility of oligonucleotide-based applications

Electron to Adsorbate Energy Transfer in Nanoparticles: Adsorption Site, Size, and Support Matter

International audienc

Elevated of NDUFA4L2 expression in colon adenocarcinoma is correlated with an unfavorable prognosis and increased immune cell infiltration

Background: Colon adenocarcinoma (COAD) is a prevalent malignancy worldwide, yet, its underlying pathogenesis and genetic characteristics are still unclear. Previous studies have suggested that NADH dehydrogenase 1 alpha subcomplex subunit 4-like 2 (NDUFA4L2) may affect tumor progression across various cancers. However, this effect on COAD has rarely been reported. Thus, this study investigated NDUFA4L2's prognostic and diagnostic relevance and explored its potential connection with immune cell infiltration in COAD. Methods: To achieve this, RNA sequencing data from Cancer Genome Atlas (TCGA) was analyzed to assess NDUFA4L2's prognostic value in COAD, and factors relevant to the prognosis of COAD, including NDUFA4L2, were scrutinized using Kaplan-Meier analyses as well as univariate and multivariate Cox regression. A nomogram model was created to project prognosis based on the results of multivariate Cox analysis. Furthermore, gene set enrichment analysis (GSEA) was employed to pinpoint key NDUFA4L2-related pathways, and single-sample GSEA (ssGSEA) on TCGA data was employed to investigate the connections of NDUFA4L2 with cancer immune infiltrations. Results: Our findings revealed significant associations of high NDUFA4L2 expression with poor overall survival, progression-free interval, and disease-specific survival of COAD patients. GSEA indicated close links of NDUFA4L2 with several signaling pathways implicated in tumorigenesis, including extracellular matrix receptor interaction, the intestinal immune network for immunoglobulin A production, natural killer (NK) cell-mediated cytotoxicity, pathways in cancer, cell adhesion molecules, mitogen-activated protein kinase signaling pathway, Hedgehog signaling pathway, transforming growth factor beta signaling pathway, and chemokine signaling pathway. Additionally, ssGSEA identified a positive link between increased NDUFA4L2 expression and higher infiltration degree of various immune cells, such as immature dendritic cells, macrophages, NK cells and dendritic cells. Conclusions: Collectively, our findings demonstrate the association of increased NDUFA4L2 expression with adverse prognosis and heightened immune cell infiltration in COAD patients

Photocatalytic Reduction Synthesis of Ternary Ag Nanoparticles/Polyoxometalate/Graphene Nanohybrids and Its Activity in the Electrocatalysis of Oxygen Reduction

Ternary Ag nanoparticles (NPs)@polyoxometalate (POM)/reduced graphene oxide (rGO) nanohybrids were prepared by a facile photoreduction method, using POM as the photocatalyst, reducing and bridging molecules. The structure of the nanohybrids was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, etc. Most importantly, both the rotating disk electrode and rotating ring-disk electrode tests indicated that the Ag NPs@POM/rGO nanohybrids exhibited excellent electrocatalytic activity towards oxygen reduction reaction via a direct four-electron transfer pathway due to the synergistic effect of Ag NPs and rGO

Fast sulfurization of nickel foam-supported nickel-cobalt carbonate hydroxide nanowire array at room temperature for hydrogen evolution electrocatalysis

International audienc