兔毛角蛋白/海藻酸钠复合纤维的制备及其性能研究

为扩展兔毛纤维的应用,基于超声波预处理兔毛纤维,采用还原法提取兔毛角蛋白,将兔毛角蛋白和海藻酸钠混合制备复合溶液,并对溶液的流变性能进行测试。采用湿法纺丝制得兔毛角蛋白/海藻酸钠复合纤维,并研究其基本性能。结果表明:采用该提取法制得的兔毛角蛋白与海藻酸钠有很好的相容性,复合溶液的表观黏度随着兔毛角蛋白含量的增加而减小。复合纤维性能随共混配比变化而变化,当兔毛角蛋白溶液与海藻酸钠溶液体积比(配比)为1∶4时,纤维凝固彻底,结晶程度适中,断裂强力达到最佳,吸湿良好,针对白度较低问题,可以增加漂白工序。     

超声波处理对咸海鲶鱼游离氨基酸含量的影响

目的研究超声波对咸海鲶鱼游离氨基酸含量的影响。方法采用氨基酸自动分析仪测定了咸海鲶鱼游离氨基酸含量。结果咸海鲶鱼中含有较多的游离氨基酸,其中丙氨酸、甘氨酸、组氨酸和丝氨酸最为丰富;超声波对氨基酸总量影响较小,在超声时间为10 min时含量最低,为15.45μmol/g鱼肉,超声波处理能造成丙氨酸、丝氨酸、酪氨酸损失,但能增加甘氨酸含量,超声波处理也会减少腥味氨基酸含量。结论在超声波处理方式和处理时间时应根据处理的目的不同谨慎选择。     

兔毛纤维的天然高分子物改性

利用不同的天然高分子物处理兔毛，结果表明：分别用1％（owb）的聚氨基酸及轻度降解壳聚糖（分子量4万左右）处理兔毛的单纤维的拉伸断裂强力为4.23、3.37cN，比未处理兔毛的断裂强力（2.39cN）明显提高，且用聚氨基酸处理兔毛具有更好的耐久性。另外，壳聚糖处理可以提高兔毛的摩擦系数，用聚氨基酸处理的兔毛的摩擦系数稍有降低。     

废弃兔毛的溶解与再利用

纺织生产特别是染整加工对环境产生的污染是现代纺织亟待解决的问题.文章研究了兔毛角蛋白粉末对染色废水上的脱色性能.采用蛋白酶减量和金属盐(ZnCl)溶胀处理相结合的方法提取角蛋白,并将其制成粉末对其进行电镜观察和红外分析,发现其微观形态呈无规则颗粒状.同时探讨并分析了pH值和角蛋白粉末用量2个因素对兔毛角蛋白粉末脱色性能的影响,得出最佳脱色工艺.在优化的条件下,发现角蛋白粉末对染液有很好的脱色作用.     

废弃兔毛中角蛋白的提取及应用

介绍了机械法、挤压法、超声波空气法、金属盐法、还原法、氧化法等方法从废弃兔毛中提取角蛋白,从纺织品的功能整理、重金属吸附、化妆品添加剂、蛋白膜等方面综述了角蛋白的应用研究进展。文章表明,角蛋白是天然蛋白质,具有良好的生物亲和性、无毒及亲肤性,含有大量的亲水基团。这些特性使得角蛋白在织物整理、化妆品添加剂以及纺丝成膜等领域的应用表现出良好的前景。     

蛋白质纤维综合利用技术及兔毛应用前景

就蛋白质纤维在提取角蛋白、生产氨基酸、用于复合材料和细胞固定化的载体等方面综合利用情况进行了综述,并对兔毛在相关领域的潜在应用进行了展望.从动物毛发中提取角蛋白的研究早已展开,并已形成了相应的方法与工艺.利用蛋白质纤维的水解制备氨基酸是我国目前重要的氨基酸生产方法.将天然蛋白质纤维用于蛋白复合体或复合纤维为蛋白质纤维的利用提供了新思路.毛发在用作微生物固定化载体方面尤其独特的优势,并已经开始了应用研究.动物毛发制成片状材料或纤维状物料,还可以用作植物的缓释有机肥和土壤调节剂.     

超声波技术在羊毛水解中的应用

为了充分利用毛纺厂大量废弃的角蛋白资源,得到水解率高、水解产物分子质量大且环保、高效、节能的羊毛水解方法,采用超声波技术辅助碱还原水解羊毛,考察了碱处理时间、超声波功率和超声波时间对水解液固体质量分数和增比黏度的影响;用GPC、XRD、FT-IR、DSC-TG等表征水解产物。结果表明：超声波对羊毛有促进水解作用,可解决羊毛水解率与水解产物分子质量之间的矛盾,较优的水解条件为碱处理3.5 h,超声波功率600 W,超声波时间3 min。     

兔毛角蛋白粉末对染料的脱色性能研究

分别采用机械研磨法和金属盐法从废弃的兔毛纤维中提取角蛋白并制成粉末,将制成的角蛋白粉末作为脱色剂,研究其对染料废水的脱色性能.结果表明:2种方法制得的兔毛角蛋白粉末对直接染料和弱酸性染料有很好的脱色性能,脱色率接近95％,在染料废水治理方面有很好的研究价值.     

兔毛白粉成分结构分析及其应用

为更好地开发利用兔毛纤维在纺纱过程中产生的兔毛白粉废弃物,采用扫描电子显微镜、双缩脲显色法、SDS-聚丙烯酰胺凝胶电泳法、傅里叶红外光谱、X射线衍射以及差示扫描量热法对从兔毛纤维表面脱落的白粉进行表观结构和成分结构探究。结果表明:兔毛白粉是从兔毛表面鳞片脱离下来的物质,长度、宽度和厚度分别为20~50μm、2.0~6.0μm和0.4~0.7μm,兔毛白粉的成分中含有蛋白质,相对分子质量主要集中在11 ku左右,可被认为是提取角蛋白的良好材料;利用还原C法从兔毛白粉中进一步提取角蛋白,将其作为一种紫外防护功能添加剂应用于化妆品中,在200~320 nm的紫外线下测试兔毛白粉,发现兔毛白粉的紫外线吸收能力优于防晒产品。     

兔毛纤维皮质结构的特性与表征

兔毛纤维髓质发达,加之皮质结构的特殊性,导致兔毛纤维的外观形态与羊毛等动物纤维具有不同性。为研究兔毛纤维皮质结构,探究它的分布特点和所占纤维的份额,使用甲酸低温处理和超声波震荡相结合的方法进行研究。根据兔毛纤维正偏皮质层结构的不同和鳞片层的存在,采用脱鳞片和不脱鳞片的皮质层染色方法,通过计算机图像软件对皮质层染色图片进行处理,得出了正偏皮质层的分布特点和比例,兔毛纤维的皮质层呈不均匀的混杂分布,正皮质细胞少于偏皮质细胞,约占37.5%。     

Antioxidant activity of β-cyclodextrin inclusion complexes containing trans-cinnamaldehyde by DPPH,ABTS and FRAP

This study was carried out to observed β-cyclodextrin (β-CD) inclusion complexes containing trans-cinnamaldehyde (CIN) by using DPPH, ABTS and FRAP assay. Antioxidative ability was compared between pure CIN and β-CD-CIN inclusion complexes and particle size, encapsulation efficiency, and temperature-dependent release of inclusion complexes were investigated. High concentration of β-CD (1.8%) as well as guest oil 1:3 molar ratio (β-CD:CIN) influenced on particle size bigger during self-assembly process. And particle sizes were increased as storage period. In the antioxidant capacity results, pure β-CD (1.8%) was antioxidative without CIN especially at FRAP assay. Antioxidant activity dramatically increased after 1:1 molar ratio (1.8% β-CD:CIN), especially at DPPH assay and ABTS^•+ assay. In this study, β-CD complexation enhanced CIN solubility and affected increase the antioxidant activity of the CIN. Moreover, we need to consider that molar ratio of between β-CD concentration and CIN is effective manufacturing condition to improve antioxidant activity of β-CD-CIN inclusion complexes.     

Preparation of a Molecular Library of Branched β-Glucan Oligosaccharides Derived from Laminarin

To study the structure of β-glucans, we developed a separation method and molecular library of β-glucan oligosaccharides. The oligosaccharides were prepared by partial acid hydrolysis from laminarin, which is a β-glucan of Laminaria digitata. They were labeled with the 2-aminopyridine fluorophore and separated to homogeneity by size-fractionation and reversed phase high-performance liquid chromatography (HPLC). Branching structures of all isomeric oligosaccharides from trimers to pentamers were determined, and a two-dimensional (2D)-HPLC map of the β-glucan oligosaccharides was made based on the data. Next, structural analysis of the longer β-glucan oligosaccharide was performed using the 2D-HPLC map. A branched decamer oligosaccharide was isolated from the β-glucan and cleaved to smaller oligosaccharides by partial acid hydrolysis. The structure of the longer oligosaccharide was successfully elucidated from the fragment structures determined by the 2D-HPLC map. The molecular library and the 2D-HPLC map described in this study will be useful for the structural analysis of β-glucans.     

Purification,Characterization, and cDNA Cloning of a Prominent β-Glucosidase from the Gut of the Xylophagous Cockroach Panesthia angustipennis spadica

Abstract: In this study, a β-glucosidase (PaBG1b) with high specific activity was purified from gut extracts of the wood-feeding cockroach Panesthia angustipennis spadica using Superdex 75 gel filtration chromatography and High-Trap phenyl hydrophobic chromatography. The protein was purified 14-fold to a single band identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis, with an apparent molecular mass of 56.7 kDa. The specific activity of the purified enzyme was 708 μmol/min/mg protein using cellobiose as substrate. To the best of our knowledge, this is the highest specific activity reported among β-glucosidases to date. The purified PaBG1b showed optimal activity at pH 5.0 and retained more than 65 % of the activity between pH 4.0 and 6.5. The activity was stable up to 50 °C for 30 min. Kinetic studies on cellobiose revealed that the K_m was 5.3 mM, and the V_max was 1,020 μmol/min/mg. The internal amino acid sequence of PaBG1b was analyzed, and two continuous sequences (a total of 39 amino acids) of the C-terminal region were elucidated. Based on these amino acid sequences, a full-length cDNA (1,552 bp) encoding 502 amino acids was isolated. The encoded protein showed high similarity to β-glucosidases from glycoside hydrolase family 1. Thus, the current study demonstrated the potential of PaBG1b for application in enzymatic biomass-conversion as a donor gene for heterologous recombination of cellulase-producing agents (fungi or bacteria) or an additive enzyme for cellulase products based on the high-performance of PaBG1b as a digestive enzyme in cockroaches.     

An overview of chemical straightening of human hair: technical aspects,potential risks to hair fibre and health and legal issues

Personal image, as it relates to external beauty, has attracted much attention from the cosmetic industry, and capillary aesthetics is a leader in consumption in this area. There is a great diversity of products targeting both the treatment and beautification of hair. Among them, hair straighteners stand out with a high demand by costumers aiming at beauty, social acceptance and ease of daily hair maintenance. However, this kind of treatment affects the chemical structure of keratin and of the hair fibre, bringing up some safety concerns. Moreover, the development of hair is a dynamic and cyclic process, where the duration of growth cycles depends not only on where hair grows, but also on issues such as the individual's age, dietary habits and hormonal factors. Thus, although hair fibres are composed of dead epidermal cells, when they emerge from the scalp, there is a huge variation in natural wave and the response to hair cosmetics. Although it is possible to give the hair a cosmetically favourable appearance through the use of cosmetic products, for good results in any hair treatment, it is essential to understand the mechanisms of the process. Important information, such as the composition and structure of the hair fibres, and the composition of products and techniques available for hair straightening, must be taken into account so that the straightening process can be designed appropriately, avoiding undesirable side effects for hair fibre and for health. This review aims to address the morphology, chemical composition and molecular structure of hair fibres, as well as the products and techniques used for chemical hair relaxing, their potential risk to hair fibre and to health and the legal aspects of their use.     

Characterization of a Non-electrophoretic Genetic Variant of β-Casein by Peptide Mapping and Mass Spectrometric Analysis

From a total of 634 Holstein milk samples, 158 were identified as homozygous β-casein A¹ according to PAGE. All the β-casein A¹ samples were isolated in pure form by anion exchange chromatography followed by tryptic hydrolysis and peptide mapping of the hydrolysates by reversed-phase HPLC. A comparison of the chromatogram revealed that the β-casein A¹ samples could be classified into two groups based on differences in elution times of fragment 114–169 due to a change in hydrophobicity caused by amino acid substitution. Mass spectrometric analysis showed that 7 β-casein samples with more hydrophobic 114–169 fragment had a higher molecular mass (difference of 16 Da) than the remaining 151 samples with less hydrophobic fragment. Amino acid composition and sequence analysis confirmed the difference in mass of peptide 114–169 by a Pro→Leu substitution at position 137. It is proposed to identify the newly found variant as β-casein G.     

Residues of β-lactam antibiotics in bovine milk: confirmatory analysis by liquid chromatography tandem mass spectrometry after microbial assay screening

A procedure for the simultaneous determination of the residues of seven β-lactam antibiotics (penicillin G, ampicillin, oxacillin, amoxicillin, dicloxacillin, cephalexin, cephapirin) in bovine raw milk using tandem liquid chromatography mass spectrometry (LC-MS/MS) is described. The antibiotics were extracted by an acetic acid solution after centrifugation and filtration. The β-lactams were separated using reversed-phase liquid chromatography. A triple quadrupole mass spectrometer was used in positive-ion mode as a detector via a Turbo Ionspray interface for electrospray ionization (ESI). The limits of detection and quantitation of the method were below the legal tolerances, except for ampicillin. The method was used to confirm 53 samples found positive by a microbial method (Delvotest SP®) at the Istituto Zooprofilattico Sperimentale per la Lombardia e l'Emilia Romagna of Brescia during 2001. Penicillin G was found in 26 samples at concentrations ranging from less than 4 to 6240 ±550 μg l^-1. Amoxicillin was found in three samples at concentrations ranging from 8.5 ±0.1 to 53.7 ±2.3 μg l^-1. Cephapirin was found in two samples at 5.7 ±0.1 and 6.4 ±0.3 μg l^-1.     

J. Cosmet. Sci., 59, 263–289 (July/August 2008)Characterization of curved hair of Japanese women with reference to internal structures and amino acid composition

The variation of hair curvature in Japanese women was quantitatively investigated and the structure of curved hair was characterized with transmission electron microscopy (TEM) and amino acid analysis. Two hundred and thirty Japanese women volunteers, aged from 10 to 70 years, were randomly selected. The evaluation of the volunteers' natural hair shape showed that 53% of Japanese women have straight hair, while the remaining 47% have curved hair (varying from a slightly wavy shape to a frizzy style). The average curl radius of the volunteers' hair was determined to be 4.4 ± 2.3 cm, and ranged widely from 0.6 to 16 cm. The TEM observation of curved hair fiber revealed an inhomogenous internal structure between the outer and inner regions of the curved shape. In relation to the inhomogeneous structure of the curved hair, different amino acid composition of the hair keratin was observed between the outer and inner regions. Interestingly, these results of the TEM observation and the amino acid analysis are analogous to the difference between the ortho-and paracortical cells in wool fibers, suggesting the universal structure of curved mammalian hair.     

Enhanced γ-CGTase Production by Bacillus Macorous with Membrane Active Substances

Some selected surfactants and alcohols were examined for their effects on γ-cyclodextrin glucanotransferase (γ-CGTase) production by Bacillus macorous WSH02-06. Both Tween 60 and n-Propyl alcohol had the ability to increase γ-CGTase yield about 1.7-fold. The investigation of fatty acid composition demonstrated that the addition of Tween 60 greatly increased the ratio of unsaturated to saturated fatty acids in cell membrane lipids, while n-propyl alcohol interfered with the proportion among unsaturated fatty acids. Study of the γ-CGTase fermentation in 5-L fermentor revealed that the addition of n-propyl alcohol improved the specific production rate and the yield of γ-CGTase.     

外泌体功能化串晶结构纤维膜的制备及其成骨分化性能

为提高合成可吸收引导骨再生膜的骨诱导活性,通过静电纺丝和溶剂诱导结晶法制备了聚己内酯(PCL)/β-磷酸三钙(β-TCP)串晶纳米纤维膜,并通过聚多巴胺的黏附作用将外泌体负载于纤维膜上进行改性,对复合纤维膜的微观形貌、化学组成、理化性能和细胞成骨分化性能进行测试与分析。结果表明:PCL/β-TCP纳米纤维上成功诱导出串晶结构,且经串晶和聚多巴胺双重修饰的纤维膜具有最佳的表面浸润性和优异的蛋白吸附能力,最终获得的外泌体功能化的串晶纳米纤维膜在串晶结构、聚多巴胺和外泌体共同作用下可促进骨髓间充质干细胞碱性磷酸酶活性的增加,有望应用于体内加速骨愈合。