Enhanced photoelectric properties of PbSnSe thin films via quick oxygen ion-implantation sensitization

Journal of Materials Science - Although chalcogenide materials continue to generate considerable interest due to great potentials for various optoelectronic devices, annealing for a long time in...     

Using refined kano model and decision trees to discover learners’ needs for teaching videos

Multimedia Tools and Applications - With the advancement of technology and the spread of the COVID19 epidemic, learning can no longer only be done through face-to-face teaching. Numerous digital...     

Resource management in UAV-assisted MEC: state-of-the-art and open challenges

Wireless Networks - Unmanned aerial vehicles (UAV) have been widely used in various fields because of their high mobility and portability. At the same time, due to the rapid development of...     

Changes in the content and antioxidative activity of β-carotene and its metabolite vitamin A during gastrointestinal digestion and absorption and optimisation of HPLC-based detection

The β-Carotene (BC), an important precursor of vitamin A (VA), possesses antioxidant activity but is fat-soluble and has low bioavailability. In previous in-vitro assays evaluating antioxidant and 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) free radical scavenging, both BC and VA showed a strong ability to scavenge radicals and protected cells from oxidative stress. Here, we used artificially simulated gastrointestinal digestion and Caco-2 cell absorption models to evaluate the bioavailability of the BC during gastrointestinal digestion and absorption using high-performance liquid chromatography (HPLC) analysis. We observed high absorptive and transfer rates of BC and detected retinol metabolites (Vitamin A). Therefore, BC can be detected in the acidic gastrointestinal environment using HPLC. Optimised method provided better separation of BC and VA in the column, improving the accuracy of the test results.     

Polymer electrets and their applications

Polymer electrets have revealed great potential application in electromechanical devices because of the low weight, large quasi-piezoelectric sensitivity, and excellent flexibility. For an electret, a permanent and macroscopic electric field exists on the surface, principally led by a macroscopic electrostatic charge on the surface or a net orientation of polar groups inside the object. Here, progress in the development of polymer electrets is reviewed. After a brief retrospect of the research courses and those typical polymer electrets that are classified into fluorine polymer and nonfluorine polymer, we present a survey on the charging methods, including corona, soft X-ray, contact, thermal and monoenergetic particle beams. The latest representative applications (i.e., power harvesting, sensors, field effect transistors, and biomedicine) based on polymer electrets are also summarized. Finally, we complete this review with a discussion on perspectives and challenges in this field.     

Improved aqueous solubility,bioaccessibility and cellular uptake of quercetin following pH-driven encapsulation in whey protein isolate

The purpose of this study was to increase the water solubility and potential bioavailability of quercetin by encapsulation in whey protein isolate (WPI) based on a green, efficient pH-driven method. According to the results, the water solubility of quercetin increased by 346.9: times after loading into WPI nanoparticles. When the initial quercetin concentration was 0.25 mg mL⁻¹ and WPI was 2% w/v, the encapsulation efficiency reached 94.1%, the Z-average diameter was 36.63 nm, and the zeta potential was −36.4 mV at pH 7.0. The fluorescence spectroscopy assay suggested the molecular complexation of quercetin and WPI at pH 12.0. X-ray diffraction assay indicated the enclosure of amorphous quercetin in WPI. Correspondingly, the bioaccessibility increased from 2.76% to 31.23% and the Caco-2 cell monolayer uptake increased from 0% to 2.12% after nanoencapsulation. This work confirmed that the pH-driven method is an effective approach to prepare WPI–quercetin nanocapsules to improve physical and potentially biological properties of quercetin.     

Double emulsion (W/O/W) gel stabilised by polyglycerol polyricinoleate and calcium caseinate as mangiferin carrier: insights on formulation and stability properties

Mangiferin (MGF) is a phenolic compound isolated from mango, but its poor solubility significantly limits its use. In this study, MGF was embedded into the inner aqueous phase of W₁/O/W₂ emulsions. Firstly, the dissolution method of MGF was determined. MGF remained stable in solution with pH 13 at 30 min, and its solubility reached 10 mg mL⁻¹. When the pH of MGF solutions was adjusted from pH 13 to pH 6, MGF did not immediately crystallise, providing sufficient time to construct the MGF-loaded W₁/O/W₂ emulsions. Subsequently, the MGF-loaded W₁/O/W₂ emulsions were constructed using polyglycerol polyricinoleate (PGPR) and calcium caseinate (CAS). The formation and stability of the W₁/O/W₂ emulsions were investigated. The MGF-loaded W₁/O/W₂ emulsions stabilised with 1% PGPR and 1% – 3% CAS exhibited a low viscosity, limited loading capacity, and poor stability. Conversely, the MGF-loaded W₁/O/W₂ emulsions stabilised by 3%PGPR–3%CAS exhibited optimal loading capacity (encapsulation efficiency = 95.31% and loading efficiency = 0.91%) and stability, which was attributed to the fact that high viscosity and gel state retarded the migration of inner aqueous phase. These results indicated that the W₁/O/W₂ emulsions stabilised by PGPR and CAS may be a potential alternative for encapsulating mangiferin.     

智慧标识网络服务机理研究进展及安全性分析

随着互联网规模的不断扩大以及应用场景的多元化,传统网络无法很好地满足新业务的动态多样化需求,因此国内外对未来网络展开了深入研究.本文首先介绍了未来互联网体系架构的研究现状.其次,介绍了具备"三层、两域"特征的智慧标识网络(Smart Identifier NETwork,SINET)体系架构,然后重点阐述了SINET服务机理在服务的命名与解析、路由机制、服务缓存、移动性、传输控制机制、可扩展性、绿色节能等关键技术方面取得的研究进展,并进一步详细分析了SINET服务机理的安全性.最后总结了SINET面临的挑战,对SINET服务机理在大规模场景部署中可能存在的问题做出讨论.