44 research outputs found
Cell-based therapy in lung regenerative medicine
Abstract
Chronic lung diseases are becoming a leading cause of death worldwide. There are few effective treatments for those patients and less choices to prevent the exacerbation or even reverse the progress of the diseases. Over the past decade, cell-based therapies using stem cells to regenerate lung tissue have experienced a rapid growth in a variety of animal models for distinct lung diseases. This novel approach offers great promise for the treatment of several devastating and incurable lung diseases, including emphysema, idiopathic pulmonary fibrosis, pulmonary hypertension, and the acute respiratory distress syndrome. In this review, we provide a concise summary of the current knowledge on the attributes of endogenous lung epithelial stem/progenitor cells (EpiSPCs), mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) in both animal models and translational studies. We also describe the promise and challenges of tissue bioengineering in lung regenerative medicine. The therapeutic potential of MSCs is further discussed in IPF and chronic obstructive pulmonary diseases (COPD).http://deepblue.lib.umich.edu/bitstream/2027.42/109470/1/40340_2013_Article_11.pd
Dimension Independent Mixup for Hard Negative Sample in Collaborative Filtering
Collaborative filtering (CF) is a widely employed technique that predicts
user preferences based on past interactions. Negative sampling plays a vital
role in training CF-based models with implicit feedback. In this paper, we
propose a novel perspective based on the sampling area to revisit existing
sampling methods. We point out that current sampling methods mainly focus on
Point-wise or Line-wise sampling, lacking flexibility and leaving a significant
portion of the hard sampling area un-explored. To address this limitation, we
propose Dimension Independent Mixup for Hard Negative Sampling (DINS), which is
the first Area-wise sampling method for training CF-based models. DINS
comprises three modules: Hard Boundary Definition, Dimension Independent Mixup,
and Multi-hop Pooling. Experiments with real-world datasets on both matrix
factorization and graph-based models demonstrate that DINS outperforms other
negative sampling methods, establishing its effectiveness and superiority. Our
work contributes a new perspective, introduces Area-wise sampling, and presents
DINS as a novel approach that achieves state-of-the-art performance for
negative sampling. Our implementations are available in PyTorch
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Generic, network schema agnostic sparse tensor factorization for single-pass clustering of heterogeneous information networks
Heterogeneous information networks (e.g. bibliographic networks and social media networks) that consist of multiple interconnected objects are ubiquitous. Clustering analysis is an effective method to understand the semantic information and interpretable structure of the heterogeneous information networks, and it has attracted the attention of many researchers in recent years. However, most studies assume that heterogeneous information networks usually follow some simple schemas, such as bi-typed networks or star network schema, and they can only cluster one type of object in the network each time. In this paper, a novel clustering framework is proposed based on sparse tensor factorization for heterogeneous information networks, which can cluster multiple types of objects simultaneously in a single pass without any network schema information. The types of objects and the relations between them in the heterogeneous information networks are modeled as a sparse tensor. The clustering issue is modeled as an optimization problem, which is similar to the well-known Tucker decomposition. Then, an Alternating Least Squares (ALS) algorithm and a feasible initialization method are proposed to solve the optimization problem. Based on the tensor factorization, we simultaneously partition different types of objects into different clusters. The experimental results on both synthetic and real-world datasets have demonstrated that our proposed clustering framework, STFClus, can model heterogeneous information networks efficiently and can outperform state-of-the-art clustering algorithms as a generally applicable single-pass clustering method for heterogeneous network which is network schema agnostic
Quantitative Assessment of Soil Physical Quality in Northern China Based on S-theory
ABSTRACT Quantitative assessment of soil physical quality is of great importance for eco-environmental pollution and soil quality studies. In this paper, based on the S-theory, data from 16 collection sites in the Haihe River Basin in northern China were used, and the effects of soil particle size distribution and bulk density on three important indices of theS-theory were investigated on a regional scale. The relationships between unsaturated hydraulic conductivityKi at the inflection point and S values (S/hi) were also studied using two different types of fitting equations. The results showed that the polynomial equation was better than the linear equation for describing the relationships between -log Ki and -logS, and -log Kiand -log (S/hi)2; and clay content was the most important factor affecting the soil physical quality index (S). The variation in the S index according to soil clay content was able to be fitted using a double-linear-line approach, with decrease in the S index being much faster for clay content less than 20 %. In contrast, the bulk density index was found to be less important than clay content. The average S index was 0.077, indicating that soil physical quality in the Haihe River Basin was good
Exosomal microRNA-Based therapies for skin diseases
Based on engineered cell/exosome technology and various skin-related animal models, exosomal microRNA (miRNA)-based therapies derived from natural exosomes have shown good therapeutic effects on nine skin diseases, including full-thickness skin defects, diabetic ulcers, skin burns, hypertrophic scars, psoriasis, systemic sclerosis, atopic dermatitis, skin aging, and hair loss. Comparative experimental research showed that the therapeutic effect of miRNA-overexpressing exosomes was better than that of their natural exosomes. Using a dual-luciferase reporter assay, the targets of all therapeutic miRNAs in skin cells have been screened and confirmed. For these nine types of skin diseases, a total of 11 animal models and 21 exosomal miRNA-based therapies have been developed. This review provides a detailed description of the animal models, miRNA therapies, disease evaluation indicators, and treatment results of exosomal miRNA therapies, with the aim of providing a reference and guidance for future clinical trials. There is currently no literature on the merits or drawbacks of miRNA therapies compared with standard treatments
Autoimmune regulator initiates the expression of promiscuous genes in thymic epithelial cells
The expression of peripheral antigens in the thymus, known as promiscuous gene expression, has been implicated in T cell tolerance and autoimmunity. Here we identified thymic epithelial cells (TECs) as the main cell type that expresses a diverse range of tissue-restricted antigens (TRAs). The TECs of a common autoimmune (non-obese diabetic [NOD]) mouse model express much lower levels of an autoimmune regulator (Aire) and TRAs than normal (Balb/c) TECs. Transfection of an Aire plasmid led to increased levels of TRA expression in cultured TECs from Balb/c and NOD mice; an increase that was enhanced by the presence of thymocytes. These data show that Aire initiates promiscuous gene expression in TECs, and that this function might be under thymocyte control
Low-friction carbon-based tribofilm from poly-alpha-olefin oil on thermally oxidized Ti6Al4V
Titanium alloy shows a poor tribological performance even under lubrication. In this paper, we report the formation of carbon-based tribofilms from poly-alpha-olefin (PAO) base oil molecules on Ti6Al4V (Ti64) samples after thermal oxidization treatment, where PAO enabling base oils to provide not only the fluid but also the solid tribofilm. Ball-on-disk tests at contact pressures of 2.0 GPa reveal that these carbon-based tribofilms on thermally oxidized Ti64 samples decrease the friction coefficient by about 3 times and wear rate by up to 2 orders magnitude as comparing to untreated one