188 research outputs found

    Uni3D: Exploring Unified 3D Representation at Scale

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    Scaling up representations for images or text has been extensively investigated in the past few years and has led to revolutions in learning vision and language. However, scalable representation for 3D objects and scenes is relatively unexplored. In this work, we present Uni3D, a 3D foundation model to explore the unified 3D representation at scale. Uni3D uses a 2D initialized ViT end-to-end pretrained to align the 3D point cloud features with the image-text aligned features. Via the simple architecture and pretext task, Uni3D can leverage abundant 2D pretrained models as initialization and image-text aligned models as the target, unlocking the great potential of 2D models and scaling-up strategies to the 3D world. We efficiently scale up Uni3D to one billion parameters, and set new records on a broad range of 3D tasks, such as zero-shot classification, few-shot classification, open-world understanding and part segmentation. We show that the strong Uni3D representation also enables applications such as 3D painting and retrieval in the wild. We believe that Uni3D provides a new direction for exploring both scaling up and efficiency of the representation in 3D domain.Comment: Code and Demo: https://github.com/baaivision/Uni3

    Recent Advances in Visible-Light Driven Photocatalysis

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    Semiconductor photocatalysis has been considered a potentially promising approach for renewable energy and environmental remediation with abundant solar light. However, the currently available semiconductor materials are generally limited by either the harvesting of solar energy or insufficient charge separation ability. To overcome the serious drawbacks of narrow light-response range and low efficiency in most photocatalysts, many strategies have been developed in the past decades. This article reviews the recent advancements of visible-light-driven photocatalysts and attempts to provide a comprehensive update of some strategies to improve the efficiency, such as doping, coupling with graphene, precipitating with metal particles, crystal growth design, and heterostructuring. A brief introduction to photocatalysts is given first, followed by an explanation of the basic rules and mechanisms of photocatalysts. This chapter focuses on recent progress in exploring new strategies to design TiO2-based photocatalysts that aim to extend the light absorption of TiO2 from UV wavelengths into the visible region. Subsequently, some strategies are also used to endow visible-light-driven Ag3PO4 with high activity in photocatalytic reactions. Next, a novel approach, using long afterglow phosphor, has been used to associate a fluorescence-emitting support to continue the photocatalytic reaction after turning off the light. The last section proposes some challenges to design high efficiency of photocatalytic systems

    JIEYUANSHEN DECOCTION EXERTS ANTIDEPRESSANT EFFECTS ON DEPRESSIVE RAT MODEL VIA REGULATING HPA AXIS AND THE LEVEL OF AMINO ACIDS NEUROTRANSMITTER

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    Background: Jieyuanshen decoction (JYAS-D) - a traditional Chinese medicine was invented by Professor Nie based on classic formulas, chaihu jia longgu muli decoction has been proved as having favorable curative effects on depression in clinical practices. The aim of this study was to investigate the antidepressant effects and its molecular mechanism of JYAS-D. Materials and Methods: The model of depression was established by Chronic Unpredictable Stress. Different doses (8.2 g/kg, 16.3 g/kg, 32.7 g/kg) of JYAS-D was orally administered; Fluoxetine was orally administered with 10mg/kg. All treatments lasted for 28 days. Sucrose preference and open-field tests were adopted to observe the behavior of rats. OPA (ortho-phthalaldehyde) derivatization method was used to detect the contents of amino acid neurotransmitter. RIA (Radiation immunity analysis) method was used to measure the serum concentrations of CORT (Corticosterone), ACTH (Adrenocorticotropic hormone) and CRH (Corticotropin-releasing hormone). ELISA (Enzyme linked immunosorbent assay) method was adopted to examine the contents of Glucocorticoid receptor (GR) and Mineralocorticoid receptor (MR) in hippocampus. Results: Compared with the model group, sucrose preference was increased in all treatment groups. The concentration of serum CORT was reduced in the middle dose of JYAS-D and control groups; the concentration of serum ACTH was reduced in the low and high-dose of JYAS-D; the concentration of serum CRH was reduced in the middle and high-dose of JYAS-D. The content of hippocampus GR was increased in the middle and high-dose of JYAS-D; the content of hippocampus Glu (Glutamic acid) was reduced among the low, middle and high-dose of JYAS-D and fluoxetine group, the ratio of Glu/γ-GABA (γ-aminobutyric acid was reduced in the low and high-dose of JYAS-D. Conclusion: JYAS-D had a significant antidepressant-like effect on rat model through regulating serum concentration of CORT, ACTH and CRH, increasing the content of hippocampus GR and regulating the equilibrium of amino acids neurotransmitter
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