70 research outputs found
The Role of Iron, Its Metabolism and Ferroptosis in Traumatic Brain Injury
Traumatic brain injury (TBI) is a structural and physiological disruption of brain function caused by external forces. It is a major cause of death and disability for patients worldwide. TBI includes both primary and secondary impairments. Iron overload and ferroptosis highly involved in the pathophysiological process of secondary brain injury. Ferroptosis is a form of regulatory cell death, as increased iron accumulation in the brain leads to lipid peroxidation, reactive oxygen species (ROS) production, mitochondrial dysfunction and neuroinflammatory responses, resulting in cellular and neuronal damage. For this reason, eliminating factors like iron deposition and inhibiting lipid peroxidation may be a promising therapy. Iron chelators can be used to eliminate excess iron and to alleviate some of the clinical manifestations of TBI. In this review we will focus on the mechanisms of iron and ferroptosis involving the manifestations of TBI, broaden our understanding of the use of iron chelators for TBI. Through this review, we were able to better find novel clinical therapeutic directions for further TBI study
Computational Emotion Analysis From Images: Recent Advances and Future Directions
Emotions are usually evoked in humans by images. Recently, extensive research
efforts have been dedicated to understanding the emotions of images. In this
chapter, we aim to introduce image emotion analysis (IEA) from a computational
perspective with the focus on summarizing recent advances and suggesting future
directions. We begin with commonly used emotion representation models from
psychology. We then define the key computational problems that the researchers
have been trying to solve and provide supervised frameworks that are generally
used for different IEA tasks. After the introduction of major challenges in
IEA, we present some representative methods on emotion feature extraction,
supervised classifier learning, and domain adaptation. Furthermore, we
introduce available datasets for evaluation and summarize some main results.
Finally, we discuss some open questions and future directions that researchers
can pursue.Comment: Accepted chapter in the book "Human Perception of Visual Information
Psychological and Computational Perspective
Controllable Mind Visual Diffusion Model
Brain signal visualization has emerged as an active research area, serving as
a critical interface between the human visual system and computer vision
models. Although diffusion models have shown promise in analyzing functional
magnetic resonance imaging (fMRI) data, including reconstructing high-quality
images consistent with original visual stimuli, their accuracy in extracting
semantic and silhouette information from brain signals remains limited. In this
regard, we propose a novel approach, referred to as Controllable Mind Visual
Diffusion Model (CMVDM). CMVDM extracts semantic and silhouette information
from fMRI data using attribute alignment and assistant networks. Additionally,
a residual block is incorporated to capture information beyond semantic and
silhouette features. We then leverage a control model to fully exploit the
extracted information for image synthesis, resulting in generated images that
closely resemble the visual stimuli in terms of semantics and silhouette.
Through extensive experimentation, we demonstrate that CMVDM outperforms
existing state-of-the-art methods both qualitatively and quantitatively.Comment: 16 pages, 11 figure
IPDreamer: Appearance-Controllable 3D Object Generation with Image Prompts
Recent advances in text-to-3D generation have been remarkable, with methods
such as DreamFusion leveraging large-scale text-to-image diffusion-based models
to supervise 3D generation. These methods, including the variational score
distillation proposed by ProlificDreamer, enable the synthesis of detailed and
photorealistic textured meshes. However, the appearance of 3D objects generated
by these methods is often random and uncontrollable, posing a challenge in
achieving appearance-controllable 3D objects. To address this challenge, we
introduce IPDreamer, a novel approach that incorporates image prompts to
provide specific and comprehensive appearance information for 3D object
generation. Our results demonstrate that IPDreamer effectively generates
high-quality 3D objects that are consistent with both the provided text and
image prompts, demonstrating its promising capability in
appearance-controllable 3D object generation.Comment: 11 pages, 7 figure
Emission color tuning and white-light generation based on photochromic control of energy transfer reactions in polymer micelles
We encapsulate a fluorescent donor molecule and a photochromic acceptor unit (photoswitch) in polymer micelles and show that the color of the emitted fluorescence is continuously changed from blue to yellow upon light-induced isomerization of the acceptor. Interestingly, white-light generation is achieved in between. With the photoswitch in the colorless form, intense blue emission from the donor is observed, while UV-induced isomerization to the colored form induces an energy transfer reaction that quenches the donor emission and sensitizes the yellow emission from the colored photoswitch. The process is reversed by exposure to visible light, triggering isomerization to the colorless form
Collabs: A Flexible and Performant CRDT Collaboration Framework
A collaboration framework is a distributed system that serves as the data
layer for a collaborative app. Conflict-free Replicated Data Types (CRDTs) are
a promising theoretical technique for implementing collaboration frameworks.
However, existing frameworks are inflexible: they are often one-off
implementations of research papers or only permit a restricted set of CRDT
semantics, and they do not allow app-specific optimizations. Until now, there
was no general framework that lets programmers mix, match, and modify CRDTs.
We solve this with Collabs, a CRDT-based collaboration framework that lets
programmers implement their own CRDTs, either from-scratch or by composing
existing building blocks. Collabs prioritizes both semantic flexibility and
performance flexibility: it allows arbitrary app-specific CRDT behaviors and
optimizations, while still providing strong eventual consistency. We
demonstrate Collabs's capabilities and programming model with example apps and
CRDT implementations. We then show that a collaborative rich-text editor using
Collabs's built-in CRDTs can scale to over 100 simultaneous users, unlike
existing CRDT frameworks and Google Docs. Collabs also has lower end-to-end
latency and server CPU usage than a popular Operational Transformation
framework, with acceptable CRDT metadata overhead.Comment: 18 pages, 19 figure
Spatiotemporal Genotype Replacement of H5N8 Avian Influenza Viruses Contributed to H5N1 Emergence in 2021/2022 Panzootic
Since 2020, clade 2.3.4.4b highly pathogenic avian influenza H5N8 and H5N1 viruses have swept through continents, posing serious threats to the world. Through comprehensive analyses of epidemiological, genetic, and bird migration data, we found that the dominant genotype replacement of the H5N8 viruses in 2020 contributed to the H5N1 outbreak in the 2021/2022 wave. The 2020 outbreak of the H5N8 G1 genotype instead of the G0 genotype produced reassortment opportunities and led to the emergence of a new H5N1 virus with G1's HA and MP genes. Despite extensive reassortments in the 2021/2022 wave, the H5N1 virus retained the HA and MP genes, causing a significant outbreak in Europe and North America. Furtherly, through the wild bird migration flyways investigation, we found that the temporal-spatial coincidence between the outbreak of the H5N8 G1 virus and the bird autumn migration may have expanded the H5 viral spread, which may be one of the main drivers of the emergence of the 2020-2022 H5 panzootic.IMPORTANCESince 2020, highly pathogenic avian influenza (HPAI) H5 subtype variants of clade 2.3.4.4b have spread across continents, posing unprecedented threats globally. However, the factors promoting the genesis and spread of H5 HPAI viruses remain unclear. Here, we found that the spatiotemporal genotype replacement of H5N8 HPAI viruses contributed to the emergence of the H5N1 variant that caused the 2021/2022 panzootic, and the viral evolution in poultry of Egypt and surrounding area and autumn bird migration from the Russia-Kazakhstan region to Europe are important drivers of the emergence of the 2020-2022 H5 panzootic. These findings provide important targets for early warning and could help control the current and future HPAI epidemics.</p
An all-photonic full color RGB system based on molecular photoswitches
On-command changes in the emission color of functional materials is a sought-after property in many contexts. Of particular interest are systems using light as the external trigger to induce the color changes. Here we report on a tri-component cocktail consisting of a fluorescent donor molecule and two photochromic acceptor molecules encapsulated in polymer micelles and we show that the color of the emitted fluorescence can be continuously changed from blue-to-green and from blue-to-red upon selective light-induced isomerization of the photochromic acceptors to the fluorescent forms. Interestingly, isomerization of both acceptors to different degrees allows for the generation of all emission colors within the red-green-blue (RGB) color system. The function relies on orthogonally controlled FRET reactions between the blue emitting donor and the green and red emitting acceptors, respectively
TP53 mutations in functional corticotroph tumors are linked to invasion and worse clinical outcome
Corticotroph macroadenomas are rare but difficult to manage intracranial neoplasms. Mutations in the two Cushing’s disease mutational hotspots USP8 and USP48 are less frequent in corticotroph macroadenomas and invasive tumors. There is evidence that TP53 mutations are not as rare as previously thought in these tumors. The aim of this study was to determine the prevalence of TP53 mutations in corticotroph tumors, with emphasis on macroadenomas, and their possible association with clinical and tumor characteristics. To this end, the entire TP53 coding region was sequenced in 86 functional corticotroph tumors (61 USP8 wild type; 66 macroadenomas) and the clinical characteristics of patients with TP53 mutant tumors were compared with TP53/USP8 wild type and USP8 mutant tumors. We found pathogenic TP53 variants in 9 corticotroph tumors (all macroadenomas and USP8 wild type). TP53 mutant tumors represented 14% of all functional corticotroph macroadenomas and 24% of all invasive tumors, were significantly larger and invasive, and had higher Ki67 indices and Knosp grades compared to wild type tumors. Patients with TP53 mutant tumors had undergone more therapeutic interventions, including radiation and bilateral adrenalectomy. In conclusion, pathogenic TP53 variants are more frequent than expected, representing a relevant amount of functional corticotroph macroadenomas and invasive tumors. TP53 mutations associated with more aggressive tumor features and difficult to manage disease
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Activatable Fluorophores Combined with Amphiphilic Polymer Carriers for Bioimaging
Self-assembling amphiphilic macromolecular nanoparticle, with a hydrophobic inner core and hydrophilic shell, can capsulate organic dyes inside. Thus, as a result, could be a valuable delivery vehicle for biology applications. We have developed a family of polymers, as supramolecular hosts, with decyl and polyethylene glycol side chains, exhibiting different hydrophobic/hydrophilic ratio, polyethylene glycol length or molecular weight. The polymers assemble into particles in neutral buffer and capture hydrophobic BODIPY in their interior. The relationship between critical concentration, dye loading property, hydrodynamic diameter and polymer structures were investigated. These provided a guideline to design self-assembling supramolecular hosts for the encapsulation of fluorescent guests and can lead to ideal delivery vehicles for the imaging probes to target locations in biosystems. In additional, a halochromic coumarin-oxazine fluorophore was connected to the side chains of an amphiphilic polymer covalently, with folate ligands as targeting agents to MCF-7 cancer cells. The pre-fluorophores did not produce any detectable fluorescence at neutral pH, but are converted into fluorophores with red emission in acidic environment. Thus, this design offers the opportunity to highlight cancer cells selectively with high brightness and optimal contrast. We also designed a photoactivatable BODIPY with two oxazines attached. As a result, the oxazine heterocycles can be disconnected stepwise upon UV irradiation and each product exhibit different emission bands. When relative amounts of chromophores are placed in a polystyrene bead matrix, the ratio of three component can be modulated by dose of activating photons. This ratiometric strategy can be applied to write barcode inside biosystems: different regions of a same animal can be labeled with different barcodes to allow the monitoring of the spatiotemporal tracking
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