129 research outputs found
Detecting ferroptosis and immune infiltration profiles in multiple system atrophy using postmortem brain tissue
BackgroundThe importance of ferroptosis and the immune system has been mentioned in the pathogenesis of α-synucleinopathy. The α-synuclein-immunoreactive inclusions that primarily affect oligodendrocytes are the hallmark of multiple system atrophy (MSA). Limited evidence implicates that iron and immune responses are involved in the pathogenesis of MSA, which is associated with neurodegeneration and α-synuclein aggregation.MethodsThe RNA sequencing data were collected from the Gene Expression Omnibus database. MSA-C-related module genes were identified through weighted gene co-expression network analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to predict the potential molecular functions. The candidate ferroptosis-related genes associated with MSA-C were obtained using a machine-learning algorithm. CIBERSORT was used to estimate the compositional patterns of the 22 types of immune cells.ResultsThe tissues for sequencing were extracted from postmortem cerebellar white matter tissues of 11 MSA-C patients and 47 healthy controls. The diagnostic ability of the six MSA-C-related ferroptosis-related genes in discriminating MSA-C from the healthy controls demonstrated a favorable diagnostic value, with the AUC ranging from 0.662 to 0.791. The proportion of CD8+ T cells in MSA-C was significantly higher than in the controls (P = 0.02). The proportion of NK cells resting in MSA-C was significantly higher than in the controls (P = 0.011).ConclusionFerroptosis and T-cell infiltration may be important pathways of disease development in MSA-C, and targeting therapies for these pathways may be disease-modifying
High-precision RCS measurement of aircraft’s weak scattering source
AbstractThe radar cross section (RCS) of weak scattering source on the surface of an aircraft is usually less than −40dBsm. How to accurately measure the RCS characteristics of weak scattering source is a technical challenge for the aircraft’s RCS measurement. This paper proposes separating and extracting the two-dimensional (2D) reflectivity distribution of the weak scattering source with the microwave imaging algorithm and spectral transform so as to enhance its measurement precision. Firstly, we performed the 2D microwave imaging of the target and then used the 2D gating function to separate and extract the reflectivity distribution of the weak scattering source. Secondly, we carried out the spectral transform of the reflectivity distribution and eventually obtained the RCS of the weak scattering source through calibration. The prototype experimental results and their analysis show that the measurement method is effective. The experiments on an aircraft’s low-scattering conformal antenna verify that the measurement method can eliminate the clutter on the surface of aircraft. The precision of measuring a −40dBsm target is 3–5dB better than the existing RCS measurement methods. The measurement method can more accurately obtain the weak scattering source’s RCS characteristics
MimicPlay: Long-Horizon Imitation Learning by Watching Human Play
Imitation learning from human demonstrations is a promising paradigm for
teaching robots manipulation skills in the real world. However, learning
complex long-horizon tasks often requires an unattainable amount of
demonstrations. To reduce the high data requirement, we resort to human play
data - video sequences of people freely interacting with the environment using
their hands. Even with different morphologies, we hypothesize that human play
data contain rich and salient information about physical interactions that can
readily facilitate robot policy learning. Motivated by this, we introduce a
hierarchical learning framework named MimicPlay that learns latent plans from
human play data to guide low-level visuomotor control trained on a small number
of teleoperated demonstrations. With systematic evaluations of 14 long-horizon
manipulation tasks in the real world, we show that MimicPlay outperforms
state-of-the-art imitation learning methods in task success rate,
generalization ability, and robustness to disturbances. Code and videos are
available at https://mimic-play.github.ioComment: 7th Conference on Robot Learning (CoRL 2023 oral presentation
VIMA: General Robot Manipulation with Multimodal Prompts
Prompt-based learning has emerged as a successful paradigm in natural
language processing, where a single general-purpose language model can be
instructed to perform any task specified by input prompts. Yet task
specification in robotics comes in various forms, such as imitating one-shot
demonstrations, following language instructions, and reaching visual goals.
They are often considered different tasks and tackled by specialized models. We
show that a wide spectrum of robot manipulation tasks can be expressed with
multimodal prompts, interleaving textual and visual tokens. Accordingly, we
develop a new simulation benchmark that consists of thousands of
procedurally-generated tabletop tasks with multimodal prompts, 600K+ expert
trajectories for imitation learning, and a four-level evaluation protocol for
systematic generalization. We design a transformer-based robot agent, VIMA,
that processes these prompts and outputs motor actions autoregressively. VIMA
features a recipe that achieves strong model scalability and data efficiency.
It outperforms alternative designs in the hardest zero-shot generalization
setting by up to task success rate given the same training data.
With less training data, VIMA still performs better than
the best competing variant. Code and video demos are available at
https://vimalabs.github.io/Comment: ICML 2023 Camera-ready version. Project website:
https://vimalabs.github.io
Wide range of droplet jetting angles by thin-film based surface acoustic waves
Nozzleless jetting of droplets with different jetting angles is a crucial requirement for 2D and 3D printing/bioprinting applications, and Rayleigh mode surface acoustic waves (SAWs) could be a potential technique for achieving this purpose. Currently, it is critical to vary the jetting angles of liquid droplets induced by SAWs and control the liquid jet directions. Generally, the direction of the liquid jet induced by SAWs generated from a bulk piezoelectric substrate such as LiNbO3 is along the theoretical Rayleigh angle of ~22o. In this study, we designed and manufactured thin-film SAW devices by depositing ZnO films on different substrates (including silicon and aluminium) to realize a wide range of jetting angles from ~16o to 55o using propagating waves generated from one interdigital transducer (IDT). We then systematically investigated different factors affecting the jetting angles, including liquid properties, applied SAW power and SAW device resonant frequency. Finally, we proposed various methods using thin-film SAW devices together with different transducer designs for realizing a wide range of jetting angles within the 3D domain
Overexpressed transferrin receptor implied poor prognosis and relapse in gastrointestinal stromal tumors
Ferroptosis, as a novel-induced programmed cell death, plays critical roles in the pathogenesis of cancers. However, the promising biomarkers of ferroptosis in gastrointestinal stromal tumor (GIST) remain to be elucidated. Herein, the expression of ferroptosis-related genes was analyzed in GIST. Among the 64 ferroptosis-related genes, transferrin receptor (TFRC) expression presented a remarkable upregulation in high-risk patients through Gene Expression Omnibus (GEO) dataset analysis, as well as its significant change after imatinib was treated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of TFRC-relevant genes revealed that TFRC expression was closely associated with cell growth pathways and metabolism-related pathways. Furthermore, patients at high risk of recurrence were more likely to exhibit high TFRC expression by immunohistochemistry. Additionally, high TFRC expression indicated an undesirable state of patient relapse, which could serve as a powerful significant independent predictor of recurrence-free survival (RFS). In summary, we systematically summarize the expression characteristics and clinical relevance of TFRC and show that TFRC can be used as a prognostic factor, which can be considered a potential therapeutic target in GIST
Reticulation is a Risk Factor of Progressive Subpleural non-Fibrotic Interstitial Lung Abnormalities
Rationale: Interstitial lung abnormalities (ILAs) are being increasingly identified in clinical
practice. In particular for subpleural non-fibrotic ILAs, the risk of progression over time and
the risk factors for progressive behavior are still largely unknown.
Objectives: To determine the age band prevalence of ILAs and the risk of radiological
progression of subpleural non-fibrotic ILAs over time in a large health check-up population,
and to identify how reticulation contributes to the risk of radiological progression.
Methods: Based on ILAs definition by the Fleischner Society, low-dose chest CT images from
community-dwelling population undergone health check-up were evaluated for ILAs.
Multivariable logistic regression was used to assess the risk of radiological progression.
Measurements and Main Results: Among 155,539 individuals, 3,300 (2.1%) were confirmed
to have ILAs: the vast majority (81.7%) were defined as subpleural non-fibrotic ILAs. The
prevalence of ILAs increased linearly with age (P for trend<0.0001). Of 454 individuals with
subpleural non-fibrotic ILAs, 198 (43.6%) had radiological progression over 4 years. The
presence of reticulation on initial imaging was an independent predictor of radiological
progression (OR 1.9; 95%CI 1.2-3.0, P=0.0040). No difference in radiological progression was
identified between subpleural non-fibrotic ILAs with extensive reticulation and subpleural
fibrotic ILAs (73.0% vs. 68.8%, P=0.7626).
Conclusions: The prevalence of ILAs increases linearly with age. Nearly half of subpleural
non-fibrotic ILAs progress radiologically over 4 years. The presence of reticulation is a risk
factor for radiological progression. Subpleural non-fibrotic ILAs with extensive reticulation
are likely to be a feature of subpleural fibrotic ILAs
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