159 research outputs found
Theranostic Upconversion Nanoparticles (II)
This theme issue provides a comprehensive collection of original research articles as well as reviews on the creation of diverse types of theranostic upconversion nanoparticles, their fundamental interactions in biology, as well as their biophotonic applications in noninvasive diagnostics and therapy
Long-tail Relation Extraction via Knowledge Graph Embeddings and Graph Convolution Networks
We propose a distance supervised relation extraction approach for
long-tailed, imbalanced data which is prevalent in real-world settings. Here,
the challenge is to learn accurate "few-shot" models for classes existing at
the tail of the class distribution, for which little data is available.
Inspired by the rich semantic correlations between classes at the long tail and
those at the head, we take advantage of the knowledge from data-rich classes at
the head of the distribution to boost the performance of the data-poor classes
at the tail. First, we propose to leverage implicit relational knowledge among
class labels from knowledge graph embeddings and learn explicit relational
knowledge using graph convolution networks. Second, we integrate that
relational knowledge into relation extraction model by coarse-to-fine
knowledge-aware attention mechanism. We demonstrate our results for a
large-scale benchmark dataset which show that our approach significantly
outperforms other baselines, especially for long-tail relations.Comment: To be published in NAACL 201
A Strategy for Prompt Phase Transfer of Upconverting Nanoparticles Through Surface Oleate-Mediated Supramolecular Assembly of Amino-β-Cyclodextrin
Lanthanide-doped upconverting nanoparticles (UCNPs) are promising for applications as wide as biosensing, bioimaging, controlled drug release, and cancer therapy. These applications require surface engineering of as-prepared nanocrystals, commonly coated with hydrophobic ligand of oleic acid, to enable an aqueous dispersion. However, literature-reported approaches often require a long time and/or multiple step treatment, along with several fold upconversion luminescence (UCL) intensity decrease. Here, we describe a strategy allowing oleate-capped UCNPs to become water-soluble and open-modified, with almost undiminished UCL, through ultrasonication of minutes. The prompt phase transfer was enabled by oleate-mediated supramolecular self-assembly of amino modified β-cyclodextrin (amino-β-CD) onto UCNPs surface. We showed that this method is valid for a wide range of UCNPs with quite different sizes (6–400 nm), various dopant types (Er, Tm, and Ho), and hierarchical structures (core, core-shell). Importantly, the amino group of amino-β-CD on the surface of treated UCNPs provide possibilities to introduce entities for biotargeting or functionalization, as exemplified here, a carboxylic-containing near infrared dye (Cy 7.5) that sensitizes UCNPs to enhance their UCL by ~4,820 fold when excited at ~808 nm. The described method has implications for all types of oleate-capped inorganic nanocrystals, facilitating their myriad bioapplications
NeuralMPS: Non-Lambertian Multispectral Photometric Stereo via Spectral Reflectance Decomposition
Multispectral photometric stereo(MPS) aims at recovering the surface normal
of a scene from a single-shot multispectral image captured under multispectral
illuminations. Existing MPS methods adopt the Lambertian reflectance model to
make the problem tractable, but it greatly limits their application to
real-world surfaces. In this paper, we propose a deep neural network named
NeuralMPS to solve the MPS problem under general non-Lambertian spectral
reflectances. Specifically, we present a spectral reflectance
decomposition(SRD) model to disentangle the spectral reflectance into geometric
components and spectral components. With this decomposition, we show that the
MPS problem for surfaces with a uniform material is equivalent to the
conventional photometric stereo(CPS) with unknown light intensities. In this
way, NeuralMPS reduces the difficulty of the non-Lambertian MPS problem by
leveraging the well-studied non-Lambertian CPS methods. Experiments on both
synthetic and real-world scenes demonstrate the effectiveness of our method
REC-MV: REconstructing 3D Dynamic Cloth from Monocular Videos
Reconstructing dynamic 3D garment surfaces with open boundaries from
monocular videos is an important problem as it provides a practical and
low-cost solution for clothes digitization. Recent neural rendering methods
achieve high-quality dynamic clothed human reconstruction results from
monocular video, but these methods cannot separate the garment surface from the
body. Moreover, despite existing garment reconstruction methods based on
feature curve representation demonstrating impressive results for garment
reconstruction from a single image, they struggle to generate temporally
consistent surfaces for the video input. To address the above limitations, in
this paper, we formulate this task as an optimization problem of 3D garment
feature curves and surface reconstruction from monocular video. We introduce a
novel approach, called REC-MV, to jointly optimize the explicit feature curves
and the implicit signed distance field (SDF) of the garments. Then the open
garment meshes can be extracted via garment template registration in the
canonical space. Experiments on multiple casually captured datasets show that
our approach outperforms existing methods and can produce high-quality dynamic
garment surfaces. The source code is available at
https://github.com/GAP-LAB-CUHK-SZ/REC-MV.Comment: CVPR2023; Project Page:https://lingtengqiu.github.io/2023/REC-MV
Aerosols Monitored by Satellite Remote Sensing
Aerosols, small particles suspended in the atmosphere, affect the air quality and climate change. Their distributions can be monitored by satellite remote sensing. Many images of aerosol properties are available from websites as the by-products of the atmospheric correction of the satellite data. Their qualities depend on the accuracy of the atmospheric correction algorithms. The approaches of the atmospheric correction for land and ocean are different due to the large difference of the ground reflectance between land and ocean. A unified atmospheric correction (UAC) approach is developed to improve the accuracy of aerosol products over land, similar to those over ocean. This approach is developed to estimate the aerosol scattering reflectance from satellite data based on a lookup table (LUT) of in situ measured ground reflectance. The results show that the aerosol scattering reflectance can be completely separated from the satellite measured radiance over turbid waters and lands. The accuracy is validated with the mean relative errors of 22.1%. The vertical structures of the aerosols provide a new insight into the role of aerosols in regulating Earth\u27s weather, climate, and air quality
- …