185 research outputs found

    GaussianBody: Clothed Human Reconstruction via 3d Gaussian Splatting

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    In this work, we propose a novel clothed human reconstruction method called GaussianBody, based on 3D Gaussian Splatting. Compared with the costly neural radiance based models, 3D Gaussian Splatting has recently demonstrated great performance in terms of training time and rendering quality. However, applying the static 3D Gaussian Splatting model to the dynamic human reconstruction problem is non-trivial due to complicated non-rigid deformations and rich cloth details. To address these challenges, our method considers explicit pose-guided deformation to associate dynamic Gaussians across the canonical space and the observation space, introducing a physically-based prior with regularized transformations helps mitigate ambiguity between the two spaces. During the training process, we further propose a pose refinement strategy to update the pose regression for compensating the inaccurate initial estimation and a split-with-scale mechanism to enhance the density of regressed point clouds. The experiments validate that our method can achieve state-of-the-art photorealistic novel-view rendering results with high-quality details for dynamic clothed human bodies, along with explicit geometry reconstruction

    Boosted ab initio Cryo-EM 3D Reconstruction with ACE-EM

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    The central problem in cryo-electron microscopy (cryo-EM) is to recover the 3D structure from noisy 2D projection images which requires estimating the missing projection angles (poses). Recent methods attempted to solve the 3D reconstruction problem with the autoencoder architecture, which suffers from the latent vector space sampling problem and frequently produces suboptimal pose inferences and inferior 3D reconstructions. Here we present an improved autoencoder architecture called ACE (Asymmetric Complementary autoEncoder), based on which we designed the ACE-EM method for cryo-EM 3D reconstructions. Compared to previous methods, ACE-EM reached higher pose space coverage within the same training time and boosted the reconstruction performance regardless of the choice of decoders. With this method, the Nyquist resolution (highest possible resolution) was reached for 3D reconstructions of both simulated and experimental cryo-EM datasets. Furthermore, ACE-EM is the only amortized inference method that reached the Nyquist resolution

    Deciphering of interactions between platinated DNA and HMGB1 by hydrogen/deuterium exchange mass spectrometry

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    A high mobility group box 1 (HMGB1) protein has been reported to recognize both 1,2-intrastrand crosslinked DNA by cisplatin (1,2-cis-Pt-DNA) and monofunctional platinated DNA using trans-[PtCl2(NH3)(thiazole)] (1-trans-PtTz-DNA). However, the molecular basis of recognition between the trans-PtTz-DNA and HMGB1 remains unclear. In the present work, we described a hydrogen/deuterium exchange mass spectrometry (HDX-MS) method in combination with docking simulation to decipher the interactions of platinated DNA with domain A of HMGB1. The global deuterium uptake results indicated that 1-trans-PtTz-DNA bound to HMGB1a slightly tighter than the 1,2-cis-Pt-DNA. The local deuterium uptake at the peptide level revealed that the helices I and II, and loop 1 of HMGB1a were involved in the interactions with both platinated DNA adducts. However, docking simulation disclosed different H-bonding networks and distinct DNA-backbone orientations in the two Pt-DNA-HMGB1a complexes. Moreover, the Phe37 residue of HMGB1a was shown to play a key role in the recognition between HMGB1a and the platinated DNAs. In the cis-Pt-DNA-HMGB1a complex, the phenyl ring of Phe37 intercalates into a hydrophobic notch created by the two platinated guanines, while in the trans-PtTz-DNA-HMGB1a complex the phenyl ring appears to intercalate into a hydrophobic crevice formed by the platinated guanine and the opposite adenine in the complementary strand, forming a penta-layer π–π stacking associated with the adjacent thymine and the thiazole ligand. This work demonstrates that HDX-MS associated with docking simulation is a powerful tool to elucidate the interactions between platinated DNAs and proteins

    Effect of trailing edge shape on hydrodynamic damping for a hydrofoil

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    Flow induced vibration on a hydrofoil may be significantly reduced with a slight modification of the trailing edge without alteration of the hydrodynamic performance. Particularly, the so called Donaldson trailing edge shape gave remarkable results and is being used in a variety of industrial applications. Nevertheless, the physics behind vibration reduction is still not understood. In the present study, we have investigated the hydrodynamic damping of a 2D hydrofoil with Donaldson trailing edge shape. The results are compared with the same hydrofoil with blunt trailing edge. The tests are carried out in EPFL high speed cavitation tunnel and two piezoelectric patches are used for the hydrofoil excitation in non-intrusive way. It was found that the hydrodynamic damping is significantly increased with the Donaldson cut. Besides, as the flow velocity is increased, the hydrodynamic damping is found to remain almost constant up to the hydrofoil resonance and then increases linearly, for both tested trailing edge shapes and for both first bending and torsion modes

    Enhancement of thermoelectric performance in n-type PbTe1−ySey by doping Cr and tuning Te:Se ratio

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    Lead telluride and its alloys have been extensively studied for medium temperature thermoelectric applications due to decent figure-of-merit (ZT) at temperature close to 900 K. However, little emphasis has been given to improve the ZT near room temperature. In this investigation, we report a systematic study of Cr doping in PbTe[subscript 1−y]Se[subscript y] with y=0, 0.25, 0.5, 0.75, 0.85, and 1. We found the peak ZT temperature increased with increasing concentration of Se. The highest ZT of ~0.6 at room temperature in Te-rich Cr[subscript 0.015]Pb[subscript 0.985]Te[subscript 0.75]Se[subscript 0.25] was obtained due to a lowered thermal conductivity and enhanced power factor resulted from high Seebeck coefficient of about −220 µV K[superscript −1] and high Hall mobility ~1120 cm[superscript 2] V[superscript −1] s[superscript −1] at room temperature. A room temperature ZT of ~0.5 and peak ZT of ~1 at about 573–673 K is shown by Se-rich sample Cr[subscript 0.01]Pb[subscript 0.99]Te[subscript 0.25]Se[subscript 0.75]. This improvement of the room temperature ZT improved the average ZT over a wide temperature range and could potentially lead to a single leg efficiency of thermoelectric conversion for Te-rich Cr[subscript 0.015]Pb[subscript 0.985]Te[subscript 0.75]Se[subscript 0.25] up to ~11% and Se-rich Cr[subscript 0.01]Pb[subscript 0.99]Te[subscript 0.25]Se[subscript 0.75] up to ~13% with cold side and hot side temperature at 300 K and 873 K, respectively, if matched with appropriate p-type legs

    Isobavachalcone exhibits antifungal and antibiofilm effects against C. albicans by disrupting cell wall/membrane integrity and inducing apoptosis and autophagy

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    Isobavachalcone (IBC) is a natural flavonoid with multiple pharmacological properties. This study aimed to evaluate the efficacy of IBC against planktonic growth and biofilms of Candida albicans (C. albicans) and the mechanisms underlying its antifungal action. The cell membrane integrity, cell metabolic viability, and cell morphology of C. albicans treated with IBC were evaluated using CLSM and FESEM analyses. Crystal violet staining, CLSM, and FESEM were used to assess the inhibition of biofilm formation, as well as dispersal and killing effects of IBC on mature biofilms. RNA-seq combined with apoptosis and autophagy assays was used to examine the mechanisms underlying the antifungal action of IBC. IBC exhibited excellent antifungal activity with 8 μg/mL of MIC for C. albicans. IBC disrupted the cell membrane integrity, and inhibited biofilm formation. IBC dispersed mature biofilms and damaged biofilm cells of C. albicans at 32 μg/mL. Moreover, IBC induced apoptosis and autophagy-associated cell death of C. albicans. The RNA-seq analysis revealed upregulation or downregulation of key genes involved in cell wall synthesis (Wsc1 and Fks1), ergosterol biosynthesis (Erg3, and Erg11), apoptisis (Hsp90 and Aif1), as well as autophagy pathways (Atg8, Atg13, and Atg17), and so forth, in response to IBC, as evidenced by the experiment-based phenotypic analysis. These results suggest that IBC inhibits C. albicans growth by disrupting the cell wall/membrane, caused by the altered expression of genes associated with β-1,3-glucan and ergosterol biosynthesis. IBC induces apoptosis and autophagy-associated cell death by upregulating the expression of Hsp90, and altering autophagy-related genes involved in the formation of the Atg1 complex and the pre-autophagosomal structure. Together, our findings provide important insights into the potential multifunctional mechanism of action of IBC
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