Heparinization and hybridization of electrospun tubular graft for improved endothelialization and anticoagulation

Supplementary data to this article can be found online at https://doi.org/10.1016/j.msec.2020.111861.Constructing biomimetic structure and immobilizing antithrombus factors are two effective methods to ensure rapid endothelialization and long-term anticoagulation for small-diameter vascular grafts. However, few literatures are available regarding simultaneous implementation of these two strategies. Herein, a nano-micro-fibrous biomimetic graft with a heparin coating was prepared via a step-by-step in situ biosynthesis method to improve potential endothelialization and anticoagulation. The 4-mm-diameter tubular graft consists of electrospun cellulose acetate (CA) microfibers and entangled bacterial nanocellulose (BNC) nanofibers with heparin coating on dual fibers. The hybridized and heparinized graft possesses suitable pore structure that facilitates endothelia cells adhesion and proliferation but prevents infiltration of fibrous tissue and blood leakage. In addition, it shows higher mechanical properties than those of bare CA and hybridized CA/BNC grafts, which match well with native blood vessels. Moreover, this dually modified graft exhibits improved blood compatibility and endothelialization over the counterparts without hybridization or heparinization according to the testing results of platelet adhesion, cell morphology, and protein expression of von Willebrand Factor. This novel graft with dual modifications shows promising as a new small-diameter vascular graft. This study provides a guidance for promoting endothelialization and blood compatibility by dual modifications of biomimetic structure and immobilized bioactive molecules.This work was supported by the National Natural Science Foundation of China (grant nos. 51973058 and 31870963), the Key Research and Development Program of Jiangxi Province (No. 20192ACB80008), and the Key Project of Natural Science Foundation of Jiangxi Province (20202ACBL204013).info:eu-repo/semantics/publishedVersio

Controllable synthesis of biomimetic nano/submicro-fibrous tubes for potential small-diameter vascular grafts

Mimicking the morphological structure of native blood vessels is critical for the development of vascular grafts. Herein, small-diameter composite vascular grafts that integrate the nanofibrous bacterial cellulose (BC) and submicrofibrous cellulose acetate (CA) were fabricated via a combined electrospinning and step-by-step in situ biosynthesis. Scanning electron microscopy (SEM) observation shows the nano/submicro-fibrous morphology and well-interconnected porous structure of the BC/CA grafts. It is found that the BC/CA graft with a suitable BC content demonstrates lower potential of thrombus formation and enhanced endothelialization as compared to the BC and CA counterparts. Western blotting and RT-qPCR results suggest that the BC/CA-2 graft promotes endothelialization by improving expressions of genes vWF-1 and CD31 and protein CD31. The in vivo tests demonstrate much lower inflammatory response to the BC/CA graft. These results suggest that the BC/CA graft shows a great potential as an artificial graft for rapid formation of an endothelial cell monolayer.National Natural Science Foundation of China (Grant no. 51973058, 31870963, 31760265) and Key Research and Development Program of Jiangxi Province (No. 20192ACB80008)info:eu-repo/semantics/publishedVersio

Micro-damage model of gas-bearing coal under load and instability identification criteria

The distribution of pores and skeletons within coal reservoirs significantly affects the migration of gases and the occurrence of gas dynamic disasters. To further explore the micro-damage mechanisms in gas-containing coal, a detailed study of the micro-damage process in gas-containing coal was conducted. Atomic force microscopy was employed to conduct in-situ tests on the surfaces of protruding and non-protruding coal samples before and after loading. The results indicate that the surface structure of the coal samples changes after loading, with a reduction in closed pore diameter, damage to some pores, and a tendency for connectivity between adjacent closed pores. Before loading, the pores in coal samples exhibit irregular distribution, while after loading, pore connectivity increases, and the number of open pore throats slightly increases. Loading leads to a reduction in the modulus of coal skeleton in protruding coal samples due to pore connectivity, while non-protruding coal samples experience internal structure compaction, resulting in a slight increase in elastic modulus due to their higher strength. Micro-damage types and concepts in coal were defined, and the stress distribution characteristics around coal pores and the coal skeleton were analyzed, revealing the micro-damage mechanisms in gas-containing coal under different conditions. Simultaneously, the factors influencing the closed-cell micro-gas explosion were discussed. The stress at the end of a slender elliptical hole is greater along the hole wall, making it more susceptible to closed-cell micro-gas explosions. Two forms of occurrence of open-pore micro-damage were described, revealing the constraining effect of the "bottleneck effect" on micro-damage. Inherent fractures were identified as the weak link in the coal skeleton, and the evolution of their rupture was analyzed. Utilizing theories such as linear elastic fracture mechanics, elastic-plastic mechanics, and permeation mechanics, criteria for detecting pore damage and coal instability under stress disturbances were established. The micro-damage characteristics of gas-containing coal and the mechanisms inducing coal and gas outbursts were summarized, and the research direction of coal and gas outburst was prospected

Novel two-stage fluidized bed-plasma gasification integrated with SOFC and chemical looping combustion for the high efficiency power generation from MSW: a thermodynamic investigation

A novel municipal solid waste (MSW)-based power generation system was proposed in this study, which consists of a bubbling fluidized-bed (BFB)-plasma gasification unit, a high-temperature solid oxide fuel cell (SOFC), a chemical looping combustion (CLC) unit and a heat recovery unit. Process simulation was conducted using Aspen PlusTM and validated by literature data. The energetic and exergetic assessment of the proposed system showed that the net electrical efficiency and exergy efficiency reached 40.9 % and 36.1 %, respectively with 99.3 % of carbon dioxide being captured. It was found that the largest exergy destruction took place in the BFB-Plasma gasification unit (476.5 kW) and accounted for 33.6 % of the total exergy destruction, which is followed by the SOFC (219.1 kW) and then CLC (208.6 kW). Moreover, the effects of key variables, such as steam to fuel ratio (STFR), fuel utilization factor (Uf), current density and air reactor operating temperature, etc., on system performance were carried out and revealed that the system efficiency could be optimized under STFR = 0.5, Uf = 0.8 and air reactor operating temperature of 1000 ºC. Furthermore, the proposed process demonstrated more than 14% improvement in net electrical efficiency in comparison with other MSW incineration and/or gasification to power processes

Comparative study of the gasification of coal and its macerals and prediction of the synergistic effects under typical entrained-bed pulverized coal gasification Conditions

This research is focused on the gasification performance of coal and its corresponding macerals as well as on the interactions among macerals under typical gasification conditions by Aspen Plus modeling. The synergistic coefficient was employed to show the degree of interactions, while the performance indicators including specific oxygen consumption (SOC), specific coal consumption (SCC), cold gas efficiency (CGE), and effective syngas (CO + H2) content were used to evaluate the gasification process. Sensitivity analyses showed that the parent coal and its macerals exhibited different gasification behaviors at the same operating conditions, such as the SOC and SCC decreased in the order of inertinite > vitrinite > liptinite, whereas CGE changed in the order of liptinite > vitrinite > inertinite. The synergistic coefficients of SOC and SCC for the simulated coals were in the range of 0.94–0.97, whereas the synergistic coefficient of CGE was 1.05–1.13. Moreover, it was found that synergistic coefficients of gasification indicators correlated well with maceral contents. In addition, the increase in temperature was found to promote the synergistic coefficients slightly, whilst at an oxygen to coal mass ratio of 0.8 and a steam to coal mass ratio of 0.8, the highest synergistic coefficient was obtained

Boosting Electrocatalytic Nitrate-to-Ammonia Conversion via Plasma Enhanced CuCo Alloy–Substrate Interaction

Electrocatalytic conversion of widely distributed nitrate from industrial wastewater into value-added ammonia was proposed as an attractive and sustainable alternative to harvesting green ammonia. Herein, CuCo alloys were facilely synthesized for nitrate conversion, while nonthermal Ar-plasma was employed to enhance the adhesion strength between the electrocatalyst and substrate interface via regulating the surface hydrophobicity and roughness. Based on Ar-plasma treatment, a high ammonia yield rate (5129.29 μg cm-2 h-1) was achieved using Cu30Co70 electrocatalyst -0.47 V vs RHE, while nearly 100% of Faradaic efficiency was achieved using Cu50Co50 electrocatalyst at -0.27 V vs RHE (reversible hydrogen electrode). Validated by in situ spectroscopy and density functional theory calculations, the high activity of the CuCo alloy was derived from the regulation of Co to weaken the strong adsorption capacity of Cu and the shift of the d-band center to lower the energy barrier, while Ar-plasma modification promoted the formation of *NO to boost nitrate conversion

Rapid Determination of Methyl Salicylate and Menthol in Activating Collaterals Oil by Near Infrared Spectroscopy

The near infrared spectra of 10 kinds of commercial collaterals oil samples were collected by liquid transmission analysis module, and the contents of methyl salicylate and menthol in collaterals oil were determined by gas chromatography-mass spectrometry (GC-MS). The quantitative analysis model of methyl salicylate content (model 1) and menthol content (model 2) was established by correlating spectral information with measured values by partial least square method (PLS) in chemometrics. Model 1 was used to detect the content of methyl salicylate in activating oil. The predicted results showed that the absolute error was in the range of -0.098~0.082%, and the relative error was in the range of -9.986~8.195%. Model 2 was used to detect menthol in activating collaterals oil. The predicted results showed that the absolute error was in the range of -0.173~0.194%, and the relative error was in the range of -7.25~9.69%. A new method for rapid and accurate determination of methyl salicylate and menthol in activating collaterals oil was established

Sex Differences and Temporal Trends in Hospitalization for Catheter Ablation of Nonvalvular Atrial Fibrillation: A Single-Center Experience for 15 Years

Background. There exist sex differences in the clinical profile, management, and outcome of atrial fibrillation (AF). Catheter ablation of AF has become a first-line therapy and has markedly made headway over the recent decades. Little is known about sex differences and temporal trends in hospitalization for catheter ablation of AF in the real-world setting. Methods. We retrospectively retrieved medical records of patients at Beijing Anzhen Hospital between January 2005 and December 2019. The patients undergoing catheter ablation of AF were enrolled. Demographical and clinical data were compared between sexes. The temporal trends of sex differences were evaluated. Results. We identified 13502 male patients (66.8%) and 6713 female patients (33.2%). The number of patients undergoing AF ablation had remarkably increased over time, but no sex differences were observed (p=0.17). The median age of women was five years older than that of men (p<0.001). The median time of in-hospital stay for the women decreased from 11 days to 4 days and for the men from 9 to 4 days. In-hospital mortality was 0.03% and 0.01% for women and men, respectively, with no significant difference between sexes. The women were more likely to have a comorbid diagnosis of hypertension and heart failure than men (p<0.001). The CHA2DS2-VA score was higher in women than in men (1.64 vs. 1.28, p<0.001). The temporal trend in the score increased in women from 1.17 to 1.81 (p<0.001) and in men from 0.91 to 1.41 (p<0.001). The percentage of patients with CHA2DS2-VA score ≥2 was higher in women than in men (49.8% vs. 35.8%, p<0.001), and the temporal trend of this sex gap was nearly doubled (8.0% in 2005–2007 vs. 15.5% in 2017–2019, p=0.03). Conclusions. Safety of catheter ablation for AF was comparable in both sexes. In contrast, the women showed a higher CHA2DS2-VA score than men. The percentage of patients with CHA2DS2-VA score ≥2 increased more quickly in women than in men. Furthermore, sex-specific research is warranted to reduce this sex disparity

Novel Strategy of Proxalutamide for the Treatment of Prostate Cancer through Coordinated Blockade of Lipogenesis and Androgen Receptor Axis

Objective: Prostate cancer (PCa) is the most common malignant tumor diagnosed in men in developed countries. In developing countries, the PCa morbidity and mortality rates are also increasing rapidly. Since androgen receptor (AR) is a key driver and plays a critical role in the regulation of PCa development, AR-targeted agents provide a key component of current therapy regimens. However, even new-generation AR antagonists are prone to drug resistance, and there is currently no effective strategy for overcoming advanced PCa aggressiveness, including drug-resistance progression. The aim of this study was to evaluate the potential efficacy and novel therapy strategy of proxalutamide (a newly developed AR antagonist) in PCa. Methods: Four PCa cell lines with various biological heterogeneities were utilized in this study, namely, androgen-sensitive/-insensitive with/without AR expression. Proliferation, migration and apoptosis assays in PCa cells were used to evaluate the effective therapeutic activity of proxalutamide. The changes in lipid droplet accumulation and lipidomic profiles were analyzed to determine the influence of proxalutamide on lipogenesis in PCa cells. The molecular basis of the effects of proxalutamide on lipogenesis and the AR axis was then further investigated. Results: Proxalutamide significantly inhibited the proliferation and migration of PCa cells, and its inhibitory effect was superior to that of enzalutamide (Enz, second-generation AR antagonist). Proxalutamide induced the caspase-dependent apoptosis of PCa cells. Proxalutamide significantly diminished the level of lipid droplets in PCa cells, changed the lipid profile of PCa cells and reduced the content of most lipids (especially triglycerides) in PCa cells. Proxalutamide attenuated de novo lipogenesis by inhibiting the expression of ATP citrate lyase (ACL), acetyl CoA carboxylase (ACC), fatty acid synthase (FASN) and sterol regulatory element-binding protein-1 (SREBP-1). Moreover, proxalutamide also decreased AR expression in PCa cells, and its inhibitory effect on lipogenesis did not depend on its ability to down-regulate AR expression. However, Enz had no effect on AR expression, lipid accumulation or lipid de novo synthesis in PCa cells. Conclusions: By co-targeting the AR axis and endogenous adipogenesis, a novel and promising strategy was established for proxalutamide to combat the progress of PCa. The unique effect of proxalutamide on the metabolic reprogramming of PCa provides a potential solution to overcome the resistance of current AR-targeted therapy, which will help to effectively prolong its clinical service life