Self-Assembling Properties and Recovery Effects on Damaged Skin Cells of Chemically Synthesized Mannosylerythritol Lipids

Mannosylerythritol lipids (MELs), which are one of the representative sugar-based biosurfactants (BSs) produced by microorganisms, have attracted much attention in various fields in the sustainable development goals (SDGs) era. However, they are inseparable mixtures with respect to the chain length of the fatty acids. In this study, self-assembling properties and structure-activity relationship (SAR) studies of recovery effects on damaged skin cells using chemically synthesized MELs were investigated. It was revealed, for the first time, that synthetic and homogeneous MELs exhibited significant self-assembling properties to form droplets or giant vesicles. In addition, a small difference in the length of the fatty acid chains of the MELs significantly affected their recovery effects on the damaged skin cells. MELs with medium or longer length alkyl chains exhibited much higher recovery effects than that of C18-ceramide NP.     

Spectroscopic study of lactonic rhodamine B immobilised on polytetrafluoroethylene porous film

Rhodamine B (RB) is frequently used in chemical sensors, where the sensing principle depends on its structural changes to lactone (L), zwitterion (Z), and cation (C) forms in response to the local environment. Compared to the Z- and C-forms, stabilising the L-form in matrices is difficult because of the required low environmental polarity. In this study, we report a simple and easy method to stabilise the L-form of RB on the surface of a polytetrafluoroethylene porous film (p-PTFE), in which the film is dipped in an ethanol solution containing RB and dried. This phenomenon was not observed on polyethylene film and cellulose filter paper in RB solutions. Furthermore, a chemical stability test for colourless RB/p-PTFE samples was conducted by exposing these samples to a humid environment. The test result indicated that, with an increase in the environmental humidity, the equilibrium shifted from the L-form to the Z-form of RB immobilised on the p-PTFE film.     

Reversible Photocontrol of Microtubule Stability by Spiropyran-Conjugated Tau-Derived Peptides

Spatiotemporal modulation of microtubules by light has become an important aspect of the biological and nanotechnological applications of microtubules. We previously developed a Tau-derived peptide as a binding unit to the inside of microtubules. Here, we conjugated the Tau-derived peptide to spiropyran, which is reversibly converted to merocyanine by light, as a reversible photocontrol system to stabilize microtubules. Among the synthesized peptides with spiropyran/merocyanine at different positions, several peptides were bound to the inside of microtubules and stabilized the structures of microtubules. The peptide with spiropyran at the N-terminus induced polymerization and stabilization of microtubules, whereas the same peptide with the merocyanine form did not exert these effects. Reversible formation of microtubules/tubulin aggregates was achieved using the peptide with spiropyran conjugated at the N-terminus and irradiation with UV and visible light. Spiropyran-conjugated Tau-derived peptides would be useful for spatiotemporal modulation of microtubule stability through reversible photocontrol of binding.     

Hot water resistance of glass‐fiber and glass‐bead reinforced thermoplastics

The hot water resistance of three kinds of short glass fiber or glass bead‐reinforced plastics [polyphenyleneether (PPE), polyphenylenesulfide (PPS), and polyoxymethylene (POM)] was studied by hot water immersion testing, tensile testing and water‐hammer fatigue testing. It was found that the degradation of the strength was observed only for the reinforced plastics under hot water immersion and that the change of the tensile strength was most drastic in glass fiber‐reinforced PPS (GFPPS). Scanning electron microscope (SEM) observations of the tensile fracture surface revealed that the change in tensile strength was attributable to the deterioration of the interface between the glass fiber and the matrix resin. The results of acoustic emission analysis also supported the conclusion that the change in strength was due to the deterioration of the interface. Although the change in the tensile strength of glass fiber‐reinforced PPE (GFPPE) was small compared with that of GFPPS, debonding between the glass fiber and the matrix resin and surface cracks was observed on the surface of the GFPPE specimens.     

A Simple Colorimetric Assay of Bleomycin-Mediated DNA Cleavage Utilizing Double-Stranded DNA-Modified Gold Nanoparticles

A colorimetric assay of DNA cleavage by bleomycin (BLM) derivatives was developed utilizing high colloidal stability on double-stranded (ds) DNA-modified gold nanoparticles (dsDNA-AuNPs) possessing a cleavage site. The assay was performed using dsDNA-AuNPs treated with inactive BLM or activated BLM (Fe(II)⋅BLM). A 10-min exposure in dsDNA-AuNPs with inactive BLM treatment resulted in a rapid color change from red to purple because of salt-induced non-crosslinking aggregation of dsDNA-AuNPs. In contrast, the addition of active Fe(II)⋅BLM retained the red color, probably because of the formation of protruding structures at the outermost phase of dsDNA-AuNPs caused by BLM-mediated DNA cleavage. Furthermore, the results of our model experiments indicate that oxidative base release and DNA-cleavage pathways could be visually distinguished with color change. The present methodology was also applicable to model screening assays using several drugs with different mechanisms related to antitumor activity. These results strongly suggest that this assay with a rapid color change could lead to simple and efficient screening of potent antitumor agents.     

基于深度学习的遥感图像道路分割

为在遥感图像中提取出来道路信息,利用深度学习技术,引入U²-Net模型进行遥感图像道路分割。相比于传统的道路提取方法,基于U²-Net方法可以实现道路的自动化提取。为验证U²-Net模型分割效果,选取U-Net、DeepLabV3+等近几年较为流行的语义分割方法进行对比试验,并进一步分析U²-Net显著图融合模块中卷积核对道路提取效果的影响。试验结果表明,U²-Net模型能较有效地提取出道路信息,模型在测试集上的平均交并比达到了76.49%,Kappa达到了0.701 2,分割精度优于U-Net、DeepLabV3+等语义分割方法。基于U²-Net模型的深度学习方法可以用于解决遥感图像中的道路分割问题,并具有较好的分割效果。     

Origin and Regulation of Self-Discharge in MXene Supercapacitors

MXene-based supercapacitors are promising electrochemical energy-storage devices due to their ultrahigh volumetric capacitance, high-power characteristics, and excellent cyclability. However, they suffer from severe self-discharging behavior while the underlying self-discharging mechanism is still unclear. Here, the self-discharge behavior of MXene-based supercapacitors from surface electronic structure of MXenes is disclosed, and a novel method to mitigate it is proposed. A superficial engineering strategy based on bio-thermal treatment is developed to effectively tailor surface electronic structure of Ti₃C₂T_x MXenes by eliminating hydroxyl terminations. With the evolution of surface electronic structure, as revealed by Kelvin probe force microscope and synchrotron radiation X-ray absorption fine structure analysis, MXene-based supercapacitors with common aqueous electrolytes show >20% decline in self-discharge rate. This decline mechanism originates from the increased work function that induces higher zero-charge potential after the removal of hydroxyl groups in MXenes. Meanwhile, the strengthened surface dipole leads to higher surface free energy between MXene and electrolytes. These two positive effects endow MXenes with weaker self-discharge kinetics. Specifically, the activation-controlled self-discharge process is greatly suppressed. Illuminating the relevance between electronic structure and self-discharge accompanying superficial engineering suppression strategy can guide to development of high-performance energy storage devices.     

An intelligent color design method for visual communication design for public crisis

During a crisis, people's emotions are dynamically affected by changes in the environment, and by the attributes of object and subject in ways that depend on an emotion's essential characteristics. Negative emotions can cause psychological harm to people, but specific visual colors can instantaneously dispel or reduce those negative emotions. We developed a color design method based on a hybrid intelligent algorithm to predict accurately the significant negative emotions of people during a public crisis, and to explore the relationship between color structure and negative emotions developed. A Fuzzy Bayesian Network prediction model was constructed of people's significant negative emotions during a public crisis. Then, the concept of color cube was proposed that related color combinations to  particular emotions. Finally, based on the emotion arousal experiment and the BP neural network, the nonlinear mapping relationship between negative emotion and color cube was analyzed to predict the fading versus stimulating color structure of the significant negative emotions. This mapping provides a reference for the color design of visual communications during a public crisis. Our results show that the prediction model of emotions and color design method were effective.     

Numerical study of the correlation between fish school arrangement and propulsive performance

Artificial Life and Robotics - We focus on the distances in flow direction and its vertical direction on three fish school arrangements, and correlate the fish school in uniform flow with fluid...     

Anticancer Activity of Reconstituted Ribonuclease S-Decorated Artificial Viral Capsid

Ribonuclease S (RNase S) is an enzyme that exhibits anticancer activity by degrading RNAs within cancer cells; however, the cellular uptake efficiency is low due to its small molecular size. Here we generated RNase S-decorated artificial viral capsids with a size of 70–170 nm by self-assembly of the β-annulus-S-peptide followed by reconstitution with S-protein at neutral pH. The RNase S-decorated artificial viral capsids are efficiently taken up by HepG2 cells and exhibit higher RNA degradation activity in cells compared with RNase S alone. Cell viability assays revealed that RNase S-decorated capsids have high anticancer activity comparable to that of standard anticancer drugs.