283 research outputs found
Similarity between the primary and secondary air-assisted liquid jet breakup mechanism
we report an ultrafast synchrotron x-ray phase contrast imaging study of the
primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate
that there exist great similarities in the phenomenology of primary breakup
with that of the secondary breakup. Especially, a membrane-mediated breakup
mechanism dominates the breakup process for a wide range of air speeds. This
finding reveals the intrinsic connections of these two breakup regimes and has
deep implications on the unified theoretical approach in treating the breakup
mechanism of high speed liquid jet.Comment: 15 pages, 4 figure
Zero-shot Skeleton-based Action Recognition via Mutual Information Estimation and Maximization
Zero-shot skeleton-based action recognition aims to recognize actions of
unseen categories after training on data of seen categories. The key is to
build the connection between visual and semantic space from seen to unseen
classes. Previous studies have primarily focused on encoding sequences into a
singular feature vector, with subsequent mapping the features to an identical
anchor point within the embedded space. Their performance is hindered by 1) the
ignorance of the global visual/semantic distribution alignment, which results
in a limitation to capture the true interdependence between the two spaces. 2)
the negligence of temporal information since the frame-wise features with rich
action clues are directly pooled into a single feature vector. We propose a new
zero-shot skeleton-based action recognition method via mutual information (MI)
estimation and maximization. Specifically, 1) we maximize the MI between visual
and semantic space for distribution alignment; 2) we leverage the temporal
information for estimating the MI by encouraging MI to increase as more frames
are observed. Extensive experiments on three large-scale skeleton action
datasets confirm the effectiveness of our method. Code:
https://github.com/YujieOuO/SMIE.Comment: Accepted by ACM MM 202
Spatio-Temporal Branching for Motion Prediction using Motion Increments
Human motion prediction (HMP) has emerged as a popular research topic due to
its diverse applications, but it remains a challenging task due to the
stochastic and aperiodic nature of future poses. Traditional methods rely on
hand-crafted features and machine learning techniques, which often struggle to
model the complex dynamics of human motion. Recent deep learning-based methods
have achieved success by learning spatio-temporal representations of motion,
but these models often overlook the reliability of motion data. Additionally,
the temporal and spatial dependencies of skeleton nodes are distinct. The
temporal relationship captures motion information over time, while the spatial
relationship describes body structure and the relationships between different
nodes. In this paper, we propose a novel spatio-temporal branching network
using incremental information for HMP, which decouples the learning of
temporal-domain and spatial-domain features, extracts more motion information,
and achieves complementary cross-domain knowledge learning through knowledge
distillation. Our approach effectively reduces noise interference and provides
more expressive information for characterizing motion by separately extracting
temporal and spatial features. We evaluate our approach on standard HMP
benchmarks and outperform state-of-the-art methods in terms of prediction
accuracy
Microvesicles secreted by macrophages shuttle invasion-potentiating microRNAs into breast cancer cells
<p>Abstract</p> <p>Background</p> <p>Tumor-associated macrophages (TAMs) are alternatively activated cells induced by interleukin-4 (IL-4)-releasing CD4<sup>+ </sup>T cells. TAMs promote breast cancer invasion and metastasis; however, the mechanisms underlying these interactions between macrophages and tumor cells that lead to cancer metastasis remain elusive. Previous studies have found microRNAs (miRNAs) circulating in the peripheral blood and have identified microvesicles, or exosomes, as mediators of cell-cell communication. Therefore, one alternative mechanism for the promotion of breast cancer cell invasion by TAMs may be through macrophage-secreted exosomes, which would deliver invasion-potentiating miRNAs to breast cancer cells.</p> <p>Results</p> <p>We utilized a co-culture system with IL-4-activated macrophages and breast cancer cells to verify that miRNAs are transported from macrophages to breast cancer cells. The shuttling of fluorescently-labeled exogenous miRNAs from IL-4-activated macrophages to co-cultivated breast cancer cells without direct cell-cell contact was observed. miR-223, a miRNA specific for IL-4-activated macrophages, was detected within the exosomes released by macrophages and was significantly elevated in the co-cultivated SKBR3 and MDA-MB-231 cells. The invasiveness of the co-cultivated breast cancer cells decreased when the IL-4-activated macrophages were treated with a miR-223 antisense oligonucleotide (ASO) that would inhibit miR-223 expression. Furthermore, results from a functional assay revealed that miR-223 promoted the invasion of breast cancer cells via the Mef2c-β-catenin pathway.</p> <p>Conclusions</p> <p>We conclude that macrophages regulate the invasiveness of breast cancer cells through exosome-mediated delivery of oncogenic miRNAs. Our data provide insight into the mechanisms underlying the metastasis-promoting interactions between macrophages and breast cancer cells.</p
Controllable Synthesis of Fluorescent Carbon Dots and Their Detection Application as Nanoprobes
Increased risk of dementia among people with a history of fractures: a systematic review and meta-analysis of population-based studies
BackgroundEmerging evidence suggests that there may be an association between a history of fractures and dementia risk, but the epidemiological findings are inconsistent. We, therefore, conducted a meta-analysis to systematically assess the risk of dementia among people with a history of fractures.MethodsWe comprehensively searched four electronic databases (PubMed, Web of Science, Embase, and Cochrane Library) for relevant literature published from inception to 10 January 2023. Longitudinal observational studies that investigated the association between any type of fracture occurrence and the subsequent risk of dementia were included for qualitative and quantitative analysis. Risk estimates were pooled using fixed-effects or random-effects models according to the level of heterogeneity. The Newcastle-Ottawa scale was used to evaluate the risk of bias in the included studies.ResultsA total of seven population-based studies involving 3,658,108 participants (136,179 with a history of fractures) were eventually included. Pooled results showed a significant association between fracture and subsequent risk of dementia [hazard ratio (HR) = 1.28, 95% confidence interval (CI): 1.11–1.48] in cohort studies. Patients with fractures at different sites showed a similar trend toward increased risk of subsequent dementia. No gender, age, region, duration of follow-up, study quality, or study design specificity were observed. Sensitivity analysis indicates that the current results are robust. No publication bias existed. The results were similar in the cohort study with the standardized incidence ratio (SIR) as the statistical measure (SIR = 1.58, 95% CI: 1.25–2.00) and in the case-control study (OR = 1.38, 95% CI: 1.18–1.61). Of note, the causal relationship between fracture and dementia was not demonstrated in this meta-analysis.ConclusionPeople with a history of fractures are at increased risk of developing dementia. Enhanced screening and preventive management of dementia in people with a history of fractures may be beneficial
Super-resolution imaging and tracking of protein–protein interactions in sub-diffraction cellular space
Imaging the location and dynamics of individual interacting protein pairs is essential but often difficult because of the fluorescent background from other paired and non-paired molecules, particularly in the sub-diffraction cellular space. Here we develop a new method combining bimolecular fluorescence complementation and photoactivated localization microscopy for super-resolution imaging and single-molecule tracking of specific protein–protein interactions. The method is used to study the interaction of two abundant proteins, MreB and EF-Tu, in Escherichia coli cells. The super-resolution imaging shows interesting distribution and domain sizes of interacting MreB–EF-Tu pairs as a subpopulation of total EF-Tu. The single-molecule tracking of MreB, EF-Tu and MreB–EF-Tu pairs reveals intriguing localization-dependent heterogonous dynamics and provides valuable insights to understanding the roles of MreB–EF-Tu interactions
Temporal change in multimorbidity prevalence, clustering patterns, and the association with mortality: findings from the China Kadoorie Biobank study in Jiangsu Province
Objectives: The characteristics of multimorbidity in the Chinese population are currently unclear. We aimed to determine the temporal change in multimorbidity prevalence, clustering patterns, and the association of multimorbidity with mortality from all causes and four major chronic diseases.
Methods: This study analyzed data from the China Kadoorie Biobank study performed in Wuzhong District, Jiangsu Province. A total of 53,269 participants aged 30–79 years were recruited between 2004 and 2008. New diagnoses of 15 chronic diseases and death events were collected during the mean follow-up of 10.9 years. Yule's Q cluster analysis method was used to determine the clustering patterns of multimorbidity. A Cox proportional hazards model was used to estimate the associations of multimorbidity with mortalities.
Results: The overall multimorbidity prevalence rate was 21.1% at baseline and 27.7% at the end of follow-up. Multimorbidity increased more rapidly during the follow-up in individuals who had a higher risk at baseline. Three main multimorbidity patterns were identified: (i) cardiometabolic multimorbidity (diabetes, coronary heart disease, stroke, and hypertension), (ii) respiratory multimorbidity (tuberculosis, asthma, and chronic obstructive pulmonary disease), and (iii) mental, kidney and arthritis multimorbidity (neurasthenia, psychiatric disorders, chronic kidney disease, and rheumatoid arthritis). There were 3,433 deaths during the follow-up. The mortality risk increased by 24% with each additional disease [hazard ratio (HR) = 1.24, 95% confidence interval (CI) = 1.20–1.29]. Compared with those without multimorbidity at baseline, both cardiometabolic multimorbidity and respiratory multimorbidity were associated with increased mortality from all causes and four major chronic diseases. Cardiometabolic multimorbidity was additionally associated with mortality from cardiovascular diseases and diabetes, with HRs of 2.64 (95% CI = 2.19–3.19) and 28.19 (95% CI = 14.85–53.51), respectively. Respiratory multimorbidity was associated with respiratory disease mortality, with an HR of 9.76 (95% CI = 6.22–15.31).
Conclusion: The prevalence of multimorbidity has increased substantially over the past decade. This study has revealed that cardiometabolic multimorbidity and respiratory multimorbidity have significantly increased mortality rates. These findings indicate the need to consider high-risk populations and to provide local evidence for intervention strategies and health management in economically developed regions
Histological and transcriptomic responses of two immune organs, the spleen and head kidney, in Nile tilapia (Oreochromis niloticus) to long-term hypersaline stress
© 2018 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/
This author accepted manuscript is made available following 12 month embargo from date of publication (February 2018) in accordance with the publisher’s archiving policyHyperosmotic stress can adversely affect fish immunity, but little is known about the histological and transcriptomic responses of immune organs in fish in a hyperosmotic environment. This study evaluated the effects of long-term hypersaline conditions (16‰) on the growth, histology and transcriptomics of the two main immune organs, the spleen and head kidney, in Nile tilapia Oreochromis niloticus relative to those reared in freshwater for eight weeks. No differences in weight gain and specific growth rate were found between fish reared under these two salinities. Hyperosmotic stress induced a congestive or enlarged spleen. Platelet- and coagulation-related gene expression was significantly decreased in tilapia at 16‰. The red cell distribution width and value of the mean corpuscular hemoglobin were significantly greater in fish at 16‰ salinity than in control fish in freshwater. A large volume of melano-macrophages in the spleen and pigment deposition in both the spleen and head kidney were observed in the histological sections in fish at 16‰ salinity. Transmission electron microscopic results showed abnormal macrophages with deposition granules in the spleen and head kidney and more neutrophils in the head kidney of fish at 16‰ than in control fish. In total, 772 and 502 genes were annotated for significantly different expression in the spleen and head kidney, respectively, and corresponded to five and one significantly changed immune system pathways, respectively. The complement pathway in the spleen was significantly down-regulated at 16‰. This study indicates that long-term exposure of Nile tilapia to a hyperosmotic environment can induce splenomegaly, reduce coagulation function, enhance phagocytic activity and down-regulate the complement pathway in the spleen. The spleen is a more sensitive organ for immune responses to chronic ambient salinity stress than the head kidney in Nile tilapia
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