145 research outputs found
Gauge Family Model and New Symmetry Breaking Scale From FCNC Processes
Based on the gauge family symmetry model which was proposed to
explain the observed mass and mixing pattern of neutrinos, we investigate the
symmetry breaking, the mixing pattern in quark and lepton sectors, and the
contribution of the new gauge bosons to some flavour changing neutral currents
(FCNC) processes at low energy. With the current data of the mass differences
in the neutral pseudo-scalar systems, we find that the
symmetry breaking scale can be as low as 300TeV and the mass of the
lightest gauge boson be about TeV. Other FCNC processes, such as the
lepton flavour number violation process
and the semi-leptonic rare decay , contain
contributions via the new gauge bosons exchanging. With the constrains got from
system, we estimate that the contribution of the new physics is
around , far below the current experimental bounds.Comment: 3figure
HOSNeRF: Dynamic Human-Object-Scene Neural Radiance Fields from a Single Video
We introduce HOSNeRF, a novel 360{\deg} free-viewpoint rendering method that
reconstructs neural radiance fields for dynamic human-object-scene from a
single monocular in-the-wild video. Our method enables pausing the video at any
frame and rendering all scene details (dynamic humans, objects, and
backgrounds) from arbitrary viewpoints. The first challenge in this task is the
complex object motions in human-object interactions, which we tackle by
introducing the new object bones into the conventional human skeleton hierarchy
to effectively estimate large object deformations in our dynamic human-object
model. The second challenge is that humans interact with different objects at
different times, for which we introduce two new learnable object state
embeddings that can be used as conditions for learning our human-object
representation and scene representation, respectively. Extensive experiments
show that HOSNeRF significantly outperforms SOTA approaches on two challenging
datasets by a large margin of 40% ~ 50% in terms of LPIPS. The code, data, and
compelling examples of 360{\deg} free-viewpoint renderings from single videos
will be released in https://showlab.github.io/HOSNeRF.Comment: Project page: https://showlab.github.io/HOSNeR
DynVideo-E: Harnessing Dynamic NeRF for Large-Scale Motion- and View-Change Human-Centric Video Editing
Despite recent progress in diffusion-based video editing, existing methods
are limited to short-length videos due to the contradiction between long-range
consistency and frame-wise editing. Prior attempts to address this challenge by
introducing video-2D representations encounter significant difficulties with
large-scale motion- and view-change videos, especially in human-centric
scenarios. To overcome this, we propose to introduce the dynamic Neural
Radiance Fields (NeRF) as the innovative video representation, where the
editing can be performed in the 3D spaces and propagated to the entire video
via the deformation field. To provide consistent and controllable editing, we
propose the image-based video-NeRF editing pipeline with a set of innovative
designs, including multi-view multi-pose Score Distillation Sampling (SDS) from
both the 2D personalized diffusion prior and 3D diffusion prior, reconstruction
losses, text-guided local parts super-resolution, and style transfer. Extensive
experiments demonstrate that our method, dubbed as DynVideo-E, significantly
outperforms SOTA approaches on two challenging datasets by a large margin of
50% ~ 95% for human preference. Code will be released at
https://showlab.github.io/DynVideo-E/.Comment: Project Page: https://showlab.github.io/DynVideo-E
NASA-Approved Rotary Bioreactor Enhances Proliferation of Human Epidermal Stem Cells and Supports Formation of 3D Epidermis-Like Structure
The skin is susceptible to different injuries and diseases. One major obstacle in skin tissue engineering is how to develop functional three-dimensional (3D) substitute for damaged skin. Previous studies have proved a 3D dynamic simulated microgravity (SMG) culture system as a “stimulatory” environment for the proliferation and differentiation of stem cells. Here, we employed the NASA-approved rotary bioreactor to investigate the proliferation and differentiation of human epidermal stem cells (hEpSCs). hEpSCs were isolated from children foreskins and enriched by collecting epidermal stem cell colonies. Cytodex-3 micro-carriers and hEpSCs were co-cultured in the rotary bioreactor and 6-well dish for 15 days. The result showed that hEpSCs cultured in rotary bioreactor exhibited enhanced proliferation and viability surpassing those cultured in static conditions. Additionally, immunostaining analysis confirmed higher percentage of ki67 positive cells in rotary bioreactor compared with the static culture. In contrast, comparing with static culture, cells in the rotary bioreactor displayed a low expression of involucrin at day 10. Histological analysis revealed that cells cultured in rotary bioreactor aggregated on the micro-carriers and formed multilayer 3D epidermis structures. In conclusion, our research suggests that NASA-approved rotary bioreactor can support the proliferation of hEpSCs and provide a strategy to form multilayer epidermis structure
Geometry and optics calibration of WFCTA prototype telescopes using star light
The Large High Altitude Air Shower Observatory project is proposed to study
high energy gamma ray astronomy ( 40 GeV-1 PeV ) and cosmic ray physics ( 20
TeV-1 EeV ). The wide field of view Cherenkov telescope array, as a component
of the LHAASO project, will be used to study energy spectrum and compositions
of cosmic ray by measuring the total Cherenkov light generated by air showers
and shower maximum depth. Two prototype telescopes have been in operation since
2008. The pointing accuracy of each telescope is crucial to the direction
reconstruction of the primary particles. On the other hand the primary energy
reconstruction relies on the shape of the Cherenkov image on the camera and the
unrecorded photons due to the imperfect connections between photomultiplier
tubes. UV bright stars are used as point-like objects to calibrate the pointing
and to study the optical properties of the camera, the spot size and the
fractions of unrecorded photons in the insensitive areas of the camera.Comment: 5 pages, 6 figures, submitted to Chinese Physics
IL-21 Modulates Release of Proinflammatory Cytokines in LPS-Stimulated Macrophages through Distinct Signaling Pathways
The aim of this study was to investigate the anti-inflammatory effect of IL-21 on LPS-induced mouse peritoneal macrophages. The results showed that IL-21 significantly inhibited LPS-induced mRNA expression of IL-1β, TNF-α, and IL-6 in macrophages, but not of IFN-γ, IL-10, CCL5, or CXCL2. ELISA analysis showed that IL-21 also suppressed LPS-induced production of TNF-α and IL-6 in culture supernatants. Western blot analysis showed that IL-21 clearly inhibited ERK and IκBα phosphorylation and NF-κB translocation in LPS-stimulated macrophages, but it increased STAT3 phosphorylation. Flow cytometric and Western blot analysis showed that IL-21 decreased M1 macrophages surface markers expression of CD86, iNOS, and TLR4 in LPS-stimulated cells. All results suggested that IL-21 decreases IL-6 and TNF-α production via inhibiting the phosphorylation of ERK and translocation of NF-κB and promotes a shift from the M1 to M2 macrophage phenotype by decreasing the expression of CD86, iNOS, and TLR4 and by increasing STAT3 phosphorylation in LPS-stimulated cells
Application of Traditional Chinese Medical Herbs in Prevention and Treatment of Respiratory Syncytial Virus
Respiratory syncytial virus (RSV) is a common viral pathogen of the lower respiratory tract, which, in the absence of effective management, causes millions of cases of severe illness per year. Many of these infections develop into fatal pneumonia. In a review of English and Chinese medical literature, recent traditional Chinese medical herb- (TCMH-) based progress in the area of prevention and treatment was identified, and the potential anti-RSV compounds, herbs, and formulas were explored. Traditional Chinese medical herbs have a positive effect on inhibiting viral attachment, inhibiting viral internalization, syncytial formation, alleviation of airway inflammation, and stimulation of interferon secretion and immune system; however, the anti-RSV mechanisms of TCMHs are complicated, which should be further investigated
The hornwort genome and early land plant evolution
Hornworts, liverworts and mosses are three early diverging clades of land plants, and together comprise the bryophytes. Here, we report the draft genome sequence of the hornwort Anthoceros angustus. Phylogenomic inferences confirm the monophyly of bryophytes, with hornworts sister to liverworts and mosses. The simple morphology of hornworts correlates with low genetic redundancy in plant body plan, while the basic transcriptional regulation toolkit for plant development has already been established in this early land plant lineage. Although the Anthoceros genome is small and characterized by minimal redundancy, expansions are observed in gene families related to RNA editing, UV protection and desiccation tolerance. The genome of A. angustus bears the signatures of horizontally transferred genes from bacteria and fungi, in particular of genes operating in stress-response and metabolic pathways. Our study provides insight into the unique features of hornworts and their molecular adaptations to live on land
Pairing symmetry and properties of iron-based high temperature superconductors
Pairing symmetry is important to indentify the pairing mechanism. The
analysis becomes particularly timely and important for the newly discovered
iron-based multi-orbital superconductors. From group theory point of view we
classified all pairing matrices (in the orbital space) that carry irreducible
representations of the system. The quasiparticle gap falls into three
categories: full, nodal and gapless. The nodal-gap states show conventional
Volovik effect even for on-site pairing. The gapless states are odd in orbital
space, have a negative superfluid density and are therefore unstable. In
connection to experiments we proposed possible pairing states and implications
for the pairing mechanism.Comment: 4 pages, 1 table, 2 figures, polished versio
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