Study on the mechanism and law of temperature,humidity and moisture content on the mechanical properties of molded fiber products

The change of temperature, humidity and moisture content (MC) will lead to the change of mechanical properties of molded fiber products (MFP). However, it is difficult to decouple the effects of temperature, humidity and MC on the mechanical properties of MFP, and predict the mechanical properties of MFP during the use. In this study, the laws and mechanism of mechanical properties of MFP with ambient temperature, humidity and MC were studied. The results showed that the direct effect of temperature (20−70 °C) on mechanical properties of MFP was insignificant, and the mechanical properties of MFP were mainly changed by MC. The MC was related to ambient temperature and humidity, and the relationship between the three could be described by the modified Guggenheim-Anderson-de Boer (GAB) model (20−70 °C and 30 %–90 % relative humidity). With the increase of MC, the elastic modulus and fracture strain was increased and decreased linearly, the yield strength and failure strength were presented GaussAmp laws, and the failure strain was presented asymptotic regressed distribution law. Two fracture modes of MFP, brittle fracture and ductile fracture, were revealed by the scanning electron microscopy of the mesoscopic fiber structure of sugarcane bagasse molded fiber products. The mathematical models and the changes of fiber structure were verified by wheat straw molded fiber products and waste paper molded fiber products. This study was contributed to understand the effects and mechanism of the change of temperature, humidity and MC on the mechanical properties of MFP.

Application of antimicrobial peptides in production life

Antibacterial peptide is a small molecular weight,a substance existing in the biological body,plays a very important role in congenital immune systems.Today,in various antibiotics,the problem of drug resistance has caused people to live an indelible impact.Since the antibacterial peptide has spectral antibacterial properties,it has the characteristics of participating in human natural immunity and no residual,and is now one of the research and development hotspots.Antibacterial peptide is a recognized substance that can replace antibiotics,and people have never stopped,and new types of antimicrobial peptides have also emerged in the Volkswagen Vision.This paper is based on the use of antimicrosis peptides in daily life,briefly describes the effects of antimicrobial peptides in medical,animal husbandry and industrial.

Preparation and Properties of Electrospun Sheath-core Modified-PMMA Nanofibers with Photoluminescence and Photochromic Functions

Multi-functional nanofibers are playing an important role in the optical field,and are widely used in fluorescence indication,product anti-counterfeit identification and smart clothing.Nanofibers with photoluminescence and photochromic functions are already attracting more interest from researchers.In this work,based on electrospun technology,the modified-PMMA nanofibers[PMMA=poly(methyl methacrylate)]with photoluminescence and photochromic functions were prepared through the design of the sheath-core structure(SCNFs 1-4).Compared with other samples,SCNF-4 shows outstanding photoluminescence and photochromic functions.SCNF-4 can produce green light and its fluorescence intensity and fluorescence lifetime can reach 7144 a.u.and 1031.32µs,respectively.In photochromic functions,SCNF-4 can show purple in 1 min under the 365 nm ultraviolet light,and the color can be preserved for more than 4 h under the sunlight.When SCNF-4 is irradiated by far infrared light,the color of the samples can fade quickly in 40 s.Under the irradiation of ultraviolet light of different wavelengths,SCNF-4 can display multi-color fluorescence and achieve a reversible transition between white and purple.The design of the sheath-core structure realizes the complementarity of photoluminescence and photochromic functions of the electrospun modified-PMMA nanofibers,which is important to promote the wide application of multi-functional nanofibers in the optical field.

Host-guest interactions based supramolecular complexes self-assemblies for amplified chemodynamic therapy with H_(2)O_(2) elevation and GSH consumption properties

Although endogenous H_(2)O_(2) is overexpressed in tumor tissue,the amount of endogenous H_(2)O_(2) is still insufficient for chemodynamic therapy(CDT).In addition,the abundant cellular glutathione(GSH)could also consume·OH for reduced CDT.Thus,the elevation of H_(2)O_(2) and the consumption of GSH in tumor tissue are essential for the increased·OH yield and amplified CDT efficacy.In this paper,hostguest interactions based supramolecular complexes self-assemblies(SCSAs)were fabricated by incorporating cinnamaldehyde(CA)and PEG-modified cyclodextrin host units(m PEG-CD-CA)with ferrocene-(phenylboronic acid pinacol ester)conjugates(Fc-BE)on the basis of CD-induced host-guest interactions.After being internalized by cancer cells,CA can be released from SCSAs through the p H-responsive acetal linkage,elevating the H2O2level by activating NADPH oxidase.Then,Fc can catalyze the H_(2)O_(2) to higher cytotoxic hydroxyl radicals(·OH).Moreover,quinone methide(QM)can be produced through H_(2)O_(2)-induced aryl boronic ester rearrangement and further consume the antioxidant GSH.In vitro and in vivo experiments demonstrate that SCSAs can be provided as potential amplified CDT nanoagents.