Biodegradable magnesium‐based scaffolds present outstanding potential to revolutionize the treatment of coronary artery diseases, in which full recovery of arteries without long‐term irritation of ...implants is anticipated for averting adverse events associated with the permanent stents. However, overfast degradation of magnesium (Mg) alloys obstructs their extensive applications in terms of early structural failure and impaired biocompatibility. Herein, a facile copper‐incorporated coating system through nonaqueous phase synthesis of polydopamine is developed to facilitate Cu(II) capture along with robust film deposited on easily corrodible Mg, which subsequently enables sustained Cu(II) elution. It remarkably enhances corrosion resistance and impedes Mg degradation, which also contributes to improved, superior cytocompatibility, and abolished hemolysis. Moreover, through simultaneous control of Cu(II) and Mg(II) release to modulate the local microenvironment, a synergistic biochemical effect on desirable vascular cell selectivity is triggered for boosted endothelial cell viability and suppressed smooth muscle cell. Stent implantation into rabbit abdominal aorta thus exhibits accelerated re‐endothelialization completed in a week, and enhanced biological outcomes, alleviated complications and prolonged structural durability in 3‐month follow‐up. Collectively, this study opens up an alternative route of deploying a multifunctional surface modification strategy tailoring active interplay with the Mg matrix for better outcomes of next‐generation bioresorbable vascular stents.
With modulation effect on vessel microenvironment, coatings capable of active interaction with biodegradable matrix make significant difference on bioresorbable vascular stent performance. Cu(II)/polydopamine coating on magnesium is constructed through nonaqueous phase polymerization and demonstrates enhanced corrosion resistance for magnesium stent. It also triggers synergistic bioeffect of released Cu(II) and Mg(II) on vascular cells selectivity, thus promoting endothelialization while alleviating restenosis.
DNA methylation is a vital modification process in the control of genetic information, which contributes to the epigenetics by regulating gene expression without changing the DNA sequence. Abnormal ...DNA methylation-both hypomethylation and hypermethylation-has been associated with improper gene expression, leading to several disorders. Two types of risk factors can alter the epigenetic regulation of methylation pathways: genetic factors and modifiable factors. Nutrition is one of the strongest modifiable factors, which plays a direct role in DNA methylation pathways. Large numbers of studies have investigated the effects of nutrition on DNA methylation pathways, but relatively few have focused on the biochemical mechanisms. Understanding the biological mechanisms is essential for clarifying how nutrients function in epigenetics. It is believed that nutrition affects the epigenetic regulations of DNA methylation in several possible epigenetic pathways: mainly, by altering the substrates and cofactors that are necessary for proper DNA methylation; additionally, by changing the activity of enzymes regulating the one-carbon cycle; and, lastly, through there being an epigenetic role in several possible mechanisms related to DNA demethylation activity. The aim of this article is to review the potential underlying biochemical mechanisms that are related to diet modifications in DNA methylation and demethylation.
A convex polytopes is a polytope that is also a convex set of points in the n-dimensional Euclidean space Rn. By preserving the same adjacency relation between vertices of a convex polytope, its ...graph is constructed. The metric dimension problem has been extensively studied for convex polytopes and other families of graphs. In this paper, we study the fault-tolerant metric dimension problem for convex polytopes. By using a relation between resolving sets and fault-tolerant resolving sets of graphs, we prove that certain infinite families of convex polytopes are the families of graphs with constant fault-tolerant metric dimension. We conclude the paper with some open problems.
Patients with critical illness due to infection with the 2019 coronavirus disease (COVID-19) show rapid disease progression to acute respiratory failure. The study aimed to screen the most useful ...predictive factor for critical illness caused by COVID-19.
The study prospectively involved 61 patients with COVID-19 infection as a derivation cohort, and 54 patients as a validation cohort. The predictive factor for critical illness was selected using LASSO regression analysis. A nomogram based on non-specific laboratory indicators was built to predict the probability of critical illness.
The neutrophil-to-lymphocyte ratio (NLR) was identified as an independent risk factor for critical illness in patients with COVID-19 infection. The NLR had an area under receiver operating characteristic of 0.849 (95% confidence interval CI, 0.707 to 0.991) in the derivation cohort and 0.867 (95% CI 0.747 to 0.944) in the validation cohort, the calibration curves fitted well, and the decision and clinical impact curves showed that the NLR had high standardized net benefit. In addition, the incidence of critical illness was 9.1% (1/11) for patients aged ≥ 50 and having an NLR < 3.13, and 50% (7/14) patients with age ≥ 50 and NLR ≥ 3.13 were predicted to develop critical illness. Based on the risk stratification of NLR according to age, this study has developed a COVID-19 pneumonia management process.
We found that NLR is a predictive factor for early-stage prediction of patients infected with COVID-19 who are likely to develop critical illness. Patients aged ≥ 50 and having an NLR ≥ 3.13 are predicted to develop critical illness, and they should thus have rapid access to an intensive care unit if necessary.
In this paper, an optimized coding tree unit (CTU)-level rate control approach is proposed for low-delay high-efficiency video coding (H.265/HEVC). Unlike the traditional explicitly estimated ...rate-distortion (R-D) model, the distributions of parameters of the estimated R-D model are considered. Accordingly, we formulate the CTU-level rate allocation for H.265/HEVC as the decision-making problem, where the objective is to minimize the summation of CTUs' expected distortion under the given rate constraint. Moreover, a two-stage Bisection-based method is proposed to solve the optimization problem, as the rate control algorithm for H.265/HEVC. The R-D performance improvements on Bjøntegaard delta bit rate demonstrate the advances of the proposed method.
Photocatalytic CO2 reduction on metal-oxide-based catalysts is promising for solving the energy and environmental crises faced by mankind. The oxygen vacancy （Vo） on metal oxides is expected to be a ...key factor affecting the efficiency of photocatalytic CO2 reduction on metal-oxide-based catalysts. Yet, to date, the question of how an Vo influences photocatalytic CO2 reduction is still unanswered. Herein, we report that, on Vo-rich gallium oxide coated with Pt nanoparticles （Vo-rich Pt/Ga203）, CO2 is photocatalytically reduced to CO, with a highly enhanced CO evolution rate （21.0umol.h-1） compared to those on Vo-poor Pt/Ga2O3 （3.9 gmol-h-1） and Pt/TiO2（P25） （6.7 gmol.h-1）. We demonstrate that the Vo leads to improved CO2 adsorption and separation of the photoinduced charges on Pt/Ga203, thus enhancing the photocatalytic activity of Pt/Ga203. Rational fabrication of an Vo is thereby an attractive strategy for developing efficient catalysts for photocatalytic CO2 reduction.
Indium-oxide (In2O3) nanobelts coated by a 5-nm-thick carbon layer provide an enhanced photocatalytic reduction of CO2 to CO and CH4, yielding CO and CH4 evolution rates of 126.6 and 27.9 μmol h–1, ...respectively, with water as reductant and Pt as co-catalyst. The carbon coat promotes the absorption of visible light, improves the separation of photoinduced electron–hole pairs, increases the chemisorption of CO2, makes more protons from water splitting participate in CO2 reduction, and thereby facilitates the photocatalytic reduction of CO2 to CO and CH4.
Mitochondria-lysosome interactions are essential for maintaining intracellular homeostasis. Although various fluorescent probes have been developed to visualize such interactions, they remain unable ...to label mitochondria and lysosomes simultaneously and dynamically track their interaction. Here, we introduce a cell-permeable, biocompatible, viscosity-responsive, small organic molecular probe, Coupa, to monitor the interaction of mitochondria and lysosomes in living cells. Through a functional fluorescence conversion, Coupa can simultaneously label mitochondria with blue fluorescence and lysosomes with red fluorescence, and the correlation between the red-blue fluorescence intensity indicates the progress of mitochondria-lysosome interplay during mitophagy. Moreover, because its fluorescence is sensitive to viscosity, Coupa allowed us to precisely localize sites of mitochondria-lysosome contact and reveal increases in local viscosity on mitochondria associated with mitochondria-lysosome contact. Thus, our probe represents an attractive tool for the localization and dynamic tracking of functional mitochondria-lysosome interactions in living cells.
The resistance distance between any two vertices of a graph G is defined as the effective resistance between them if each edge of G is replaced by a unit resistor. The Kirchhoff index Kf(G) is the ...sum of the resistance distances between all the pairs of vertices in G. The vertex bipartiteness vb of a graph G is the minimum number of vertices whose deletion from G results in a bipartite graph. In this paper, we characterize the graph having the minimum Kf(G) values among graphs with a fixed number n of vertices and fixed vertex bipartiteness, 1≤vb≤n−3.
Increasing evidence confirms that exosome‐mediated transfer of microRNAs can influence cancer progression including tumor cell invasion, cell proliferation, and drug resistance via cell–cell ...communication. However, the potential role of exosomal‐miR‐1260b in lung adenocarcinoma (LAC) remains poorly understood. Thus, this study focused on investigating the function of exosomal‐miR‐1260b on cell invasion. Exosomal‐miR‐1260b was found to be higher in plasma of patients with LAC than that of healthy persons via quantitative real‐time polymerase chain reaction assay. The sensitivity and specificity of exosomal‐miR‐1260b (cutoff point: 2.027) were 72% and 86%, and area under the curve of 0.845 (95% CI = 0.772–0.922). Elevated expression of miR‐1260b in LAC tissues was positively correlated with exosomal‐miR‐1260b in plasma (r = .642, p < .05). Furthermore, ceramide biosynthesis regulated exosomal‐miR‐1260b secretion. Exosome‐mediated transfer of miR‐1260b promoted A549 cell invasion and was still functional inside A549 cells. Moreover, exosomal‐miR‐1260b regulated Wnt/β–catenin signaling pathway by inhibiting sFRP1 and Smad4. This study identified a new regulation mechanism involving in cell invasion by exosome‐mediated tumor‐cell‐to‐tumor‐cell communication. Targeting exosome‐microRNAs may provide new insights into the diagnosis and treatment of LAC.
Our previous study has identified that miR‐1260b was increased in non‐small‐cell lung cancer and regulated cell behaviors. Thus, the aim of this study was to illustrate that exosomal‐miR‐1260b was increased in plasma of patients with lung adenocarcinoma, and might be a diagnostic biomarker. In vitro, miR‐1260b derived from H1299 cells could be transferred to A549 cells via exosomes. Moreover, this transferred miR‐1260b could promote A549 cell invasion through Wnt/β–catenin signaling pathway.
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