Attaching Different Kinds of Proteinaceous Nanospheres to a Variety of Fabrics Using Ultrasound Radiation

The application of a rapid, non-destructive, cost-effective technique such as ultrasonic emulsification for the coating of different textiles was explored. The technical benefits for this research were the generation of multifunctional materials and their combinations through environmentally friendly processing technologies. We have shown for the first time that ultrasonic waves can be used to coat proteinaceous micro- and nanospheres (PM) of BSA (Bovine Serum Albumin) protein and casein on the surface of cotton and polyester (PE) fabrics. The creation and the anchoring of the microbubbles to the fabrics were performed by a one-step reaction, and the process is usually stopped after 3 min. The PM of bovine serum albumin (BSA) bonded to cotton and polyester fabrics has shown stability for ∼9 months. The PMs were shown to be attached more strongly to the polyester than to the cotton, and sustained stronger washing conditions on PE. The diameter of the BSA and the casein spheres on cotton was in the range of 0.8–1.0 μm, while on the PE it varied between 60 and 120 nm.     

角质酶在涤纶织物表面改性中的应用

针对涤纶织物亲水性较差的问题,采用特异腐质霉(H.insolens)来源的角质酶对其表面进行改性。通过单因素变量试验对反应残液进行紫外光吸光度测试,确定角质酶处理涤纶织物的优化工艺条件:角质酶用量为100 U/mL,时间为72 h,pH值为8.5,温度为60 ℃。在此条件下,加入表面活性剂Trition X-100(为0.1%)能显著提高角质酶催化水解涤纶织物的产物释放量。测定了反应残液中产物的种类、处理前后织物的亲水性和染色性能,并对涤纶织物表面形貌以及表面化学成分进行表征,分析涤纶的酶法改性机制。结果表明:角质酶水解涤纶产物主要是单(对苯二甲酸-2-羟基乙酯)(MHET)和对苯二甲酸(TPA);角质酶处理后涤纶织物的接触角由93.4°降至83.1°;处理后织物的亚甲基蓝染色深度值显著增加。     

EFFECT OF MANNITOL TREATMENT ON ULTRASOUND EMISSION DURING TEXTURE PROFILE ANALYSIS OF POTATO AND APPLE TISSUE

An ultrasound acoustic emission (AE) signal was recorded during texture profile analysis (TPA) of potato and apple tissue with different texture. The acoustic sensor was in contact with the sample through solid medium. Texture of the tissue was controlled by soaking it in different mannitol solutions. Both TPA and AE parameters change with the texture of potato and apple samples. However, correlation coefficients of linear regression of acoustic parameters are higher than TPA parameters and all of them are significant at a higher confidence level. Critical stress and strain indicate micro‐cracking of the material and they increase with decreasing tissue turgor. The ratio of the critical stress to hardness allows an analysis of sound duration. The sound lasts longer when the tissue is more turgid as a result of the decrease of critical stress to hardness ratio. Counts of AE recorded in the whole TPA test decreased logarithmically with tissue osmolality. The article showed that contact AE can be used for texture evaluation of potato and apple tissue.     

Dyeing in catalase-treated bleaching baths

The conventional rinsing after bleaching to remove the residual hydrogen peroxide, harmful to the reactive colorants, was replaced by enzymatic cleaning using catalases. The catalase-treated bleaching liquor was reused for dyeing. Though no hydrogen peroxide was detected after the enzymatic process, the bleaching bath composition caused unacceptable colour changes on dyed fabrics. By varying the parameters of the dyeing process – dye, salt, alkali and enzyme concentrations – the colour difference could be reduced significantly and a good dyeing result could be achieved.     

NMR and molecular modelling studies on elastase inhibitor-peptides for wound management

Proteases play an important and critical role in the physiological process of wound repair. However, excessive and unregulated release of proteolytic enzymes (e.g., elastase) mediates abnormal degradation of healthy tissues, which leads to inflammatory disorders such as chronic wounds. Thus, it is of therapeutic interest to develop novel synthetic inhibitor-peptides of elastase, which can restore the balance between the free enzyme and the endogenous inhibitors in chronic wounds. In previous works, we have reported two different drug delivery systems to release novel elastase inhibitors to the wound site. In both systems synthetic peptides (KRCCPDTCGIKCL-Pep4 and KRMMPDTMGIKML-Pep4M) based on the primary structure of the endogenous elastase inhibitor, secretory leucocyte protease inhibitor, were used as active material. Phosphorylation of the reported peptides prompts significant structural differences, which reflects in distinct inhibitory capacity towards elastase. These structural modifications were prompted by electrostatic interactions and hydrogen bonds established from the peptide phosphoresidue. The current study was also extended to another synthetic peptide (WCTASVPPQCY-PepBBI) that is based on the reactive loop of another elastase inhibitor, the Bowmen-Birk inhibitor. PepBBI, phosphorylated and non-phosphorylated, displays similar behaviour to Pep4 and Pep4M. The structural modifications reported herein were evaluated by two-dimensional nuclear magnetic resonance and molecular modelling approaches.     

CRISPNESS AND CRUNCHINESS JUDGMENT OF APPLES BASED ON CONTACT ACOUSTIC EMISSION

Contact acoustic emission (AE) measurement, together with a puncture test, were used to evaluate the crispness and crunchiness of three apple cultivars. A storage program was used to induce changes in apple crispness and crunchiness. The instrumental measurements were compared with the results of sensory evaluation.
It was found that crispness and crunchiness could be evaluated instrumentally by measuring firmness, AE events, mean AE amplitude or the product of AE events and mean AE amplitude. For one cultivar, however, firmness was not correlated with any sensory attribute. Generally, the best correlation with sensory attributes was found for the exponential value of AE events. Contact AE allows the measurement of sensory crispness or crunchiness for a given apple cultivar or independently for any apple cultivar. Contact AE can be considered as a useful method for the evaluation of sound properties of wet-crisp foods.

PRACTICAL APPLICATIONS

Contact acoustic emission method can be used for instrumental evaluation of crispness and crunchiness of apples. The method allows more accurate evaluation of these attributes than firmness measurement. There is a chance to extend the application to other wet-crisp foods and to use the method together with other destructive tests, like texture profile analysis or single edge notched bend.     

Effect of temperature and bath composition on the dyeing of cotton with catalase-treated bleaching effluent

Conventional rinsing to remove residual hydrogen peroxide after the bleaching of cotton fabric can be replaced by enzymatic cleaning using catalases. Our previous study showed that dyeing in such catalase-treated bleaching baths results in a shade change on the dyed fabrics. The aim of this present study was to investigate the reasons for the unacceptable colour differences of the dyed fabrics. Experiments were performed to study the possible temperature-dependent dye interactions in the standard dyebath, and in the dyebath prepared with bleaching effluent. Fluorescence emission spectra were used to detect changes in the structure of the catalase related to the thermal unfolding and denaturing of the protein. It was found that the colour difference on the dyed textiles could be attributed to the temperature-dependent dye-enzyme interaction and precipitation, as well as to the complexity of the bleaching bath composition.     

INFLUENCE OF CELL SIZE AND CELL WALL VOLUME FRACTION ON FAILURE PROPERTIES OF POTATO AND CARROT TISSUE

This article presents the influence of cell size and cell wall volume fraction on the failure parameters of potato tuber and carrot tissue. Confocal scanning laser microscope was used for obtaining images of the cell structure of the tissues. The mean cell face area and the cell wall volume fraction obtained from the images was compared with work to failure, failure stress, failure strain and secant modulus obtained in a compression test of potato and carrot tissue at two strain rates. Bigger cells and less amount of cell wall material weakened the tissue, which was visible as a linear decrease in the parameters: work to failure, failure stress and failure strain. There were differences between potato and carrot in the secant modulus. For carrot, the secant modulus changed with microstructural parameters, whereas for potato, the secant modulus did not depend on these values. The strain rate decreases all the failure properties for potato. For carrot, only the work to failure was affected by the strain rate.     

减轻后水洗中的靛蓝再沾色

本文就后水洗步骤从棉织物上去除物理吸附的靛蓝以及减轻靛蓝以及减轻靛蓝对织物回染（“粘色”）的可能性作了研究。试验并比较了各种不同的化学药品和纺织助剂的作用。研究结果表明，在研究的范围内去沾染效果与表面活性剂的化学结构无关，但在乙氧基化程度和净洗力之间存在着近乎直线的关系。应用复配的常规净洗剂可以获得最好的结果。     

Properties of discontinuous gold thin films deposited on a silicon substrate

Experimental results on the dependence on deposition conditions of the electrical resistance and gauge factor of discontinuous gold films in the vicinity of the percolation threshold are reported. The three-dimensional nature of the films is emphasized. The gauge factor reveals anomalous behaviour.