Chitosan-Templated Bio-coloration of Cotton Fabrics via Laccase-Catalyzed Polymerization of Hydroquinone

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.There is an increasing interest in the development of enzymatic coloration of textile fabrics as an alternative to conventional textile dyeing processes, which is successful for dyeing protein fibers. However, unmodified cotton fabrics are difficult to be dyed through enzyme catalysis due to the lack of affinity of biosynthesized dyes to cotton fibers. In order to improve the enzyme‐catalyzed dyeability of cotton fibers, chitosan was used to coat cotton fabrics as template. A novel and facile bio‐coloration technique using laccase catalysis of hydroquinone was developed to dye chitosan‐templated cotton fabrics. The polymerization of hydroquinone with the template of chitosan under the laccase catalysis was monitored by ultraviolet‐vis spectrophotometer on the absorbance of reaction solution. A significant peak of UV‐vis spectrum at 246 nm corresponding to large conjugated structures appeared and increased with increasing the duration of enzymatic catalysis. The effect of different treatment conditions on the laccase‐catalyzed dyeing of cotton fabric was investigated to determine their optimal parameters of laccase‐catalyzed coloration. Fourier‐transform infrared spectroscopy spectra demonstrated the formation of H‐bond and Schiff base reaction between chitosan and polymerized hydroquinone. Scanning electron microscopy indicated that the surface of dyed cotton fiber was much rougher than that of the control sample. Moreover, X‐ray photoelectron spectroscopy also revealed the existence of the chitosan/polymerized hydroquinone complex and polymerized hydroquinone on the dyed cotton fibers. This chitosan‐templated approach offers possibility for biological dyeing coloration of cotton fabrics and other cellulosic materials

Enzymatic coloration and finishing of wool with laccase and polyethylenimine

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Enzymes have been widely used in the textile wet processing. The precise reaction specificity of an enzyme has been utilised for specific or targeted textile finishing without causing undesirable fibre damage. Laccases are important enzymes for their application in textile processing due to their great versatility and capability of catalysing the oxidation of a broad range of substrates. The investigation of laccase-catalysed coloration towards either wool or polyethylenimine was carried out. It is understood that amino groups from wool and polyethylenimine are involved in the formation of polymeric colour during laccase catalysation of catechin and gallic acid. The colour depth and shrink-resistance of wool can be improved significantly by incorporating a multi-primary amine compound, such as polyethylenimine, and a crosslinking agent, such as glycerol diglycidyl ether, in the enzymatic coloration process of wool. This demonstrated the potential to achieve combined coloration and shrink-resistant finishing for wool fabrics

Why does frugality influence the recycling intention of waste materials?

Waste recycling significantly impacts the sustainable development of society and the ecological environment, contributing to a vital role within the waste management hierarchy. This paper presents a research model that investigates the influence mechanism of consumers’ frugality on their recycling intentions. This study collected 420 valid samples to test the model with regression analysis. The empirical results show that consumers’ frugality exerts a direct and positive effect on their recycling intention. Except for the positive direct effect, perceived value mediates the relationship between frugality and recycling intention. Besides, environmental concern strengthens the positive relationship between frugality and recycling intention. The findings of this study can better explain the recycling intention, thereby providing a basis for the government and enterprises to formulate policies and measures to promote recycling behavior

Laccase-catalyzed polymerization of hydroquinone incorporated with chitosan oligosaccharide for enzymatic coloration of cotton

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Chitosan oligosaccharide (COS), a water-soluble carbohydrate obtained from chemical or enzymatic hydrolysis of chitosan, has similar structure and properties to non-toxic, biocompatible, and biodegradable chitosan. However, COS has many advantages over chitosan due to its low molecular weight and high water solubility. In the current work, COS was incorporated in the laccase-catalyzed polymerization of hydroquinone. The laccase-catalyzed polymerization of hydroquinone with or without COS was investigated by using simple structure of glucosamine hydrochloride as an alternative to COS to understand the mechanism of COS-incorporated polymerization of hydroquinone. Although polyhydroquinone can be regarded as the polymeric colorant with dark brown color, there is no affinity or chemical bonding between polyhydroquinone and cotton fibers. Cotton fabrics were successfully in-situ dyed into brown color through the laccase-catalyzed polymerization of hydroquinone by incorporating with COS as a template. The presence of COS enhanced the dye uptake of polyhydroquinone on cotton fibers due to high affinity of COS to cotton and covalent bonding between COS and polyhydroquinone during laccase catalysis. This novel approach not only provides a simple route for the biological coloration of cotton fabrics but also presents a significant way to prepare functional textiles with antibacterial property

M1 muscarinic receptors inhibit L-type Ca2+ current and M-current by divergent signal transduction cascades

Ion channels reside in a sea of phospholipids. During normal fluctuations in membrane potential and periods of modulation, lipids that directly associate with channel proteins influence gating by incompletely understood mechanisms. In one model, M(1)-muscarinic receptors (M(1)Rs) may inhibit both Ca(2+) (L- and N-) and K(+) (M-) currents by losing a putative interaction between channels and phosphatidylinositol-4,5-bisphosphate (PIP(2)). However, we found previously that M(1)R inhibition of N-current in superior cervical ganglion (SCG) neurons requires loss of PIP(2) and generation of a free fatty acid, probably arachidonic acid (AA) by phospholipase A(2) (PLA(2)). It is not known whether PLA(2) activity and AA also participate in L- and M-current modulation in SCG neurons. To test whether PLA(2) plays a similar role in M(1)R inhibition of L- and M-currents, we used several experimental approaches and found unanticipated divergent signaling. First, blocking resynthesis of PIP(2) minimized M-current recovery from inhibition, whereas L-current recovered normally. Second, L-current inhibition required group IVa PLA(2) [cytoplasmic PLA(2) (cPLA(2))], whereas M-current did not. Western blot and imaging studies confirmed acute activation of cPLA(2) by muscarinic stimulation. Third, in type IIa PLA(2) [secreted (sPLA(2))](-/-)/cPLA(2)(-/-) double-knock-out SCG neurons, muscarinic inhibition of L-current decreased. In contrast, M-current inhibition remained unaffected but recovery was impaired. Our results indicate that L-current is inhibited by a pathway previously shown to control M-current over-recovery after washout of muscarinic agonist. Our findings support a model of M(1)R-meditated channel modulation that broadens rather than restricts the roles of phospholipids and fatty acids in regulating ion channel activity

Laccase-catalyzed polymerization of diaminobenzenesulfonic acid for pH-responsive colour-changing and conductive wool fabrics

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.In recent years, there has been an extensive interest in the research of smart fabrics and functional textiles. The present work has successfully developed the enzymatic approach for dyed wool fabrics in possession of special pH-responsive colour-changing and conductive properties, via in-situ polymerization of 2,5-diaminobenzenesulfonic acid (DABSA) by laccase from Trametes versicolor. The enzymatically synthesized product, poly(2,5-diaminobenzenesulfonic acid) (PDABSA), were characterized by FT-IR, UV-Vis spectrophotometry and matrix assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). The redox property and thermal stability of the polymer products were studied by cyclic voltammetry (CV) and TGA analysis, respectively. The results proved that the resulting polymer reached to 2 KDa and showed strong pH-dependence of UV-Vis absorption, electrochemical activity and high thermal stability. Utilizing the doping/dedoping process of PDABSA, the dyed wool fabrics were endowed with a pH-dependent redox potential. Furthermore, the dyed wool fabrics exhibited reversible colour change from dark purple at pH 1.8 to yellowish-brown at pH 10.0, indicating that the PDABSA showed unusual pH-dependent colour-changing properties on dyed wool fabrics

Laccase-catalyzed poly(ethylene glycol)-templated ‘zip’ polymerization of caffeic acid for functionalization of wool fabrics

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link

How Does Green Product Knowledge Effectively Promote Green Purchase Intention?

Knowledge can influence the whole decision-making process of consumers. While green product knowledge is often conceptualized as a direct antecedent of green purchase intention, empirical findings in support of this relationship are inconsistent. Based on 236 samples, this study investigates how green product knowledge promotes consumers’ green purchase intention. Results show that green trust and perceived consumer effectiveness partly mediate the relationship between green product knowledge and green purchase intention. The relationship between green trust and green purchase intention is positively moderated by perceived price. Compared with low perceived price, green trust has a greater effect on green purchase intention in the case of high perceived price. However, the relationship between perceived consumer effectiveness and green purchase intention is not moderated by perceived price. This study provides a new insight into green product knowledge and how to promote green purchase intention, and the findings help government and enterprises to formulate strategies to promote consumers’ green purchase intention

Hypoxia promotes gastric cancer malignancy partly through the HIF-1α dependent transcriptional activation of the long non-coding RNA GAPLINC

Hypoxia-inducible factor (HIF) activates the transcription of genes involved in cancer progression. Recently, HIF was reported to regulate the transcription of non-coding RNAs. Here, we show that the transcription of a long non-coding RNA (lncRNA), Gastric Adenocarcinoma Associated, Positive CD44 Regulator, Long Intergenic Non-Coding RNA (GAPLINC), is directly activated by HIF-1α in gastric cancer (GC). GAPLINC was overexpressed in GC tissues and promoted tumor migration and invasive behavior. GAPLINC overexpression was associated with poor prognosis in GC patients. Luciferase reporter assays and chromatin immunoprecipitation assays confirmed that HIF-1α binds to the promoter region of GAPLINC and activates its transcription. GAPLINC knockdown inhibited hypoxia-induced tumor proliferation in vivo. Taken together, our results identified a novel role for HIF transcriptional pathways in GC tumorigenesis mediated by the regulation of the lncRNA GAPLINC, and suggest GAPLINC as a novel therapeutic target for reversing chemoradioresistance and prolonging survival