Investigation of human hair fibers using lateral force microscopy

Atomic force microscopy (AFM) and lateral force microscopy (LFM) were used to investigate the morphologic and surface changes associated with various surface modifications to human hair. These included extraction with a series of solvents, bleaching, and treatment with a cationic copolymer. The study assessed the ability of these techniques to distinguish the changes in surface properties, including morphology and friction coefficient, as manifested in changes brought about by the indicated surface modifications. While topographic morphology can easily be investigated with contact AFM. LFM offers an additional tool for probing the surface distribution of oils and waxes. The removal of surface lipids from the fiber surface was accomplished using soxhlet extraction with t-butanol and n-hexane, while the free internal lipids (within the fiber structure) were removed by extraction with a mixture of chloroform and methanol (70:30, v/v). In addition, the surface of hair was modified with the cationic polymer, co(vinyl pyrrolidone-methacrylamidopropyl trimethylammonium chloride [PVP/MAPTAC]), and its distribution on the surface was monitored. Ambient AFM and LFM studies of surface modified and native fibers clearly indicate that when investigated as a function of tip loading force, the different modifications result in changes of the friction coefficient, which increase in this order: native, bleached, solvent extracted, and polymer-treated hair. Friction images show surface variations that are interpreted as areas of varying lipid film coverage. In addition, topographic images of the fibers show the presence of small pores, which become increasingly prevalent upon solvent extraction.     

Morphological, nanomechanical and cellular structural characterization of human hair and conditioner distribution using torsional resonance mode with an atomic force microscope

Characterization of the cellular structure and chemical and physical properties of hair are essential to develop better cosmetic products and advance the biological and cosmetic sciences. Although the morphology of the fine cellular structure of human hair has traditionally been investigated using scanning electron microscopy and transmission electron microscopy, atomic force microscopy can be used for characterization in ambient conditions without requiring specific sample preparations and surface treatment. In this study, the tapping and torsional resonance modes in an atomic force microscope are compared for measurements of stiffness and viscoelastic properties. The materials were mapped using amplitude and phase angle imaging. The torsional resonance mode showed advantages in resolving the in-plane (lateral) heterogeneity of materials. This mode was used for investigating and characterizing the fine cellular structure of human hair. Various cellular structures (such as the cortex and the cuticle) of human hair and fine sublamellar structures of the cuticle, such as the A-layer, the exocuticle, the endocuticle and the cell membrane complex were easily identified. The distribution and thickness of conditioner on the treated hair surface affects the tribological properties of hair. The thickness of the conditioner was estimated using force distance measurements with an atomic force microscope.     

超高效液相色谱-串联质谱法测定染发剂中9种染料

建立了同时测定染发剂中9种染料的超高效液相色谱-串联质谱分析方法。样品用甲醇进行超声提取,以10 mmol/L乙酸铵水溶液-乙腈为流动相,BEH-C18色谱柱(2.1 mm×100 mm,1.7μm)分离待测物,采用电喷雾离子源,正离子扫描和多反应监测(MRM)模式检测,外标法进行定量。9种染料羟乙基-2-硝基-p-甲苯胺、4-羟丙氨基-2-硝基苯酚、4-氨基-N,N-二甲基苯胺、3-硝基-p-羟乙氨基苯酚、2,6-二羟乙氨基甲苯、2-甲基-5-羟乙氨基苯酚、5-氨基-6-氯-2-甲基苯酚、2,6-二甲氧基-3,5-吡啶二胺盐酸盐和6-氨基间甲酚的检出限分别为1.7,0.84,0.27,3.4,0.034,1.2,7.0,0.17和0.20 mg/kg。样品加标回收实验的平均加标回收率为90.0%~110.0%,相对标准偏差为1.4%~8.6%(n=6)。该方法快速简便,定量准确,能够满足染发剂中染料含量的分析检测要求。     

非物质文化遗产生存困境及其对策——以东台发绣为例

东台发绣在当代社会发展中面临着价值困境与生存危机。通过问卷调查和实地调研考察,分析东台发绣的非物质文化遗产保护现状,提出缓解其生存困境的策略:坚持"以人为本"的原则,从发绣艺术的创造者和接受者角度,创造有利条件促进其传承、发扬和利用;以文化产业化发展思路为东台发绣注入新鲜活力,走出一条文化与经济相结合、开发与保护相促进的艺术繁荣发展之路。     

从与谢野晶子和她的《乱发》看女性的吟唱

本文揭示黑发中蕴藏着的传统审美情趣和乱发的深层含义,比较与谢野晶子和传统女歌人的恋歌,分析她们之间不同的恋爱观及其产生的主要原因,进而阐明《乱发》为封建旧道学们所不容的关键所在,强调其大胆的表现手法、积极的恋爱观是对传统儒教道德观的一种挑战,至今仍具有现实意义.     

兔绒和羊绒纤维性能对比研究

通过对比实验研究兔绒和羊绒纤维的结构特征与物理化学性能,分析了两种纤维之间的异同和混纺纱开发的前景.结果表明,兔绒与山羊绒的各项性能之间虽然存在差异,但差异都不大,可以进行交叉混纺.两种纤维都有很大程度的卷曲,手感柔软,内部分子成份与结构基本一致,各项强伸性能接近,都耐酸不耐碱;同时兔绒纤维因表面光滑,摩擦系数较小,纤维间的抱合力较差,另外兔绒纤维的质量比电阻明显高于羊绒纤维,其在加工与穿着过程中易起静电,这些是兔绒与羊绒纤维进行混纺时要特别注意的地方.     

避暑山庄四季有景

避暑山庄的特点是规模大,内容丰富,它既有北国风光,又兼具江南景色,是以真山真水取胜。山庄外建有金碧辉煌、庄严雄伟的寺庙群,称“外八庙”,使山庄与外八庙形成了一个空间整体。避暑山庄是古典园林中的佳作,山庄春色柔丽、略嫌清新;暑期爽神、景色迷人;难得金秋、尤为佳妙;严冬素雅、神态肃然。由于季节变化,景色亦有不同。     

论建筑形态美中构成因素的作用

建筑形态美的要素是形与色 ,形与色是设计中构成的基本元素 ,试图通过对其分析和探讨 ,启发设计者的创作思维 ,旨在促进建筑艺术的发展     

Synchrotron nanoscopy imaging study of scalp hair in breast cancer patients and healthy individuals: Difference in medulla loss and cortical membrane enhancements

Nanoscopic synchrotron X‐ray imaging was performed on scalp hair samples of patients with breast cancer and healthy individuals to investigate any structural differences as diagnostic tool. Hair strands were divided into 2‐3 segments along the strands from root to tip, followed by imaging either in projection or in CT scanning with a monochromatic 6.78‐keV X‐ray using zone‐plate optics with a resolving power of 60 nm. All the examined cancer hairs exhibited medulla loss with cancer stage‐dependent pattern; complete loss, discontinuous or trace along the strands. In contrast, medullas were well retained without complete loss in the healthy hair. In the CT‐scanned axial images, the cortical spindle compartments had no contrast in the healthy hair, but appeared hypointense in contrast to the surrounding hyperintense cortical membrane complex in the cancer hair. In conclusion, observation of medulla loss and cortical membrane enhancements in the hair strands of breast cancer patients demonstrated structural variations in the cancer hair, providing a new platform for further synchrotron X‐ray imaging study of screening breast cancer patients. Microsc. Res. Tech. 79:23–30, 2016. © 2015 Wiley Periodicals, Inc.