Single Human Hair Research Articles

Low-Viscous, Dilute Phase Adhesive from Dense Polyphenolic Coacervates of Poly(vinyl alcohol) and Tannic acid.

This study explores a polyphenolic coacervate, named VATA, formed by poly(vinyl alcohol) (PVA) and tannic acid (TA). Distinct from conventional studies that have focused on the bottom, dense phase of coacervates, this research emphasizes the top, dilute phase, low-viscous coacervate liquid termed liquid-VATA (l-VATA). Due to TA's capability of intermolecular association as well as adhesiveness, phenomena not typically observed in the upper dilute phase of standard polyelectrolyte-based coacervates are revealed. At first glance, the dilute phase l-VATA coacervate resembles a water-like, low-viscous mixture solution of PVA, TA, and PVA/TA complexes. However, analysis shows that nearly all of the TA molecules associate with PVA chains, forming PVA/TA complexes. Furthermore, supraparticular association was observed between PVA/TA complex nanoparticles upon applying external shear force. A broad survey of shear rate and strain showed that the solution exhibited sequential shear-thickening, followed by shear-thinning behavior. The water-like, low viscosity of l-VATA unexpectedly reveals robust adhesiveness and thus able to lift an entire mouse using just a single human hair strand. Even in cases of failure, no interfacial failure was detected between mouse and human hair. In addition to enabling hair-to-hair bonding, our study also showcases the efficacy of l-VATA in facilitating hair-to-skin adhesion. The results illustrate how the lower viscosity of l-VATA can be exploited for a wide range of industrial and cosmetic applications, allowing the formulation of thin, uniform adhesive layers, something unachievable with the dense, viscous VATA glue. Thus, this study highlights the importance of investigating the top dilute phase of coacervates, shedding light on an area often underestimated compared to the bottom dense phase reported in prevalent coacervate studies.

Fabrication and Characterization of Jute/Human Hair Reinforced Polyester Hybrid Composite

Fibre reinforced composites are used in automotive, defence and structural applications because of their economic and ecological advantage but they have limitation of lower mechanical strength. To balance this limitation of mechanical properties, hybrid composites are being manufactured. In this paper jute and human hair was selected for preparation of jute / human hair reinforced polyester hybrid composite. Human hair was selected because it is non-biodegradable and has high tensile strength. A single human hair can bear 1.5 Newton load. Recently various researcher started work towards development of bio-composites. It has been found that a mechanical property increases after adding hair in hybrid composites. Mechanical properties such as tensile strength, young modulus, and flexural strength were also compared with the already published jute composite results. To understand the fracture behaviour of composite morphology of the fractured surface was done by scanning electron microscope (SEM). The composite application is in environmental conditions addition and thus it is subjected to moisture presence, therefore study of water absorption behaviour of fabricated composite was also studied.

Čalbmi čalmmis ja suoldnečalmmit suoidnečalmmis

North Saami čalbmi ‘eye’ (< Proto-Uralic *ćilmä) has cognates in all Uralic languages, and everywhere they refer to the visual organs of humans and animals. However, scholars have barely paid attention to the grammatical functions of čalbmi in compound-like formations such as suoldnečalbmi “dew eye”, suoidnečalbmi “grass eye”, varračalbmi “blood eye”, jiekŋačalbmi “ice eye”, vuoktačalbmi “hair eye” and muorječalbmi “berry eye”. This article examines such expressions as so-called singulatives – grammatical means for individuating a single referent from a group or mass (i.e., ‘a single drop of dew’, ‘a single blade of grass’, ‘a single drop of blood’, ‘a single crystal of ice’, ‘a single human hair’ and ‘a single berry’). The article mainly discusses morphological, syntactic and semantic features of singulatives in North Saami and other present-day Saami languages, but comparable singulatives in Khanty, Mansi and Samoyed languages as well as in Hungarian suggest that singulative expressions such as *weri-ćilmä ‘a single drop of blood’, *jäŋi-ćilmä ‘a single crystal of ice; hailstone’ and *me̮rja-ćilmä ‘a single berry’ can, in principle, be reconstructed all the way back to Proto-Uralic.

Division of force among layers constituting human hair during bending and tension

Human hair is a three-layered structure comprising the inner medulla, middle cortex, and outer cuticle layer. When a hair is subjected to bending or tensile load, each of these layers absorbs a certain amount of the force applied. However, the magnitude of the force absorbed by each layer is not easy to estimate. This is because, in addition to Young's modulus of each layer, the absorption depends on the area of each layer as seen in the cross-section. This study used a strategic way of combining experiment and theory and found that Young's modulus of the cuticle layer changes in the face of bending and tension. Considering this, the ratio of force sharing inside a human hair was estimated. Bending and tensile tests were conducted on single human hairs to determine the structural elasticity for both deformations which expresses the deformability of the hair independent of its external dimensions. Moreover, Young's modulus of each layer was determined by nanoindentation of hair cross-section. By comparing the structural elasticity determined experimentally with that determined theoretically, Young's modulus of the cuticle layer against tension was found to be 25% of that against bending. Based on this finding, it was found that the cuticle layer bears 35% of the force endured during bending, and the cortex bears the rest; when subjected to tension, the cortex bears more than 90% of the force.

AN UNUSUAL CAUSE OF GAMMA CAMERA CONTAMINATION.

This report is of an unusual case of radioactive contamination of a gamma camera after scanning two individuals who had been treated 3 days prior with ablative doses of radioiodine (131I) for thyroid cancer. A combination of observed half-life and pulse-height spectroscopy were employed to identify the radio-contaminant. The source of the contamination was eventually found to be a single human hair, presumably contaminated by the individual sucking her hair while waiting for the scan to start. This case demonstrates that hair can be contaminated by saliva and potentially other bodily fluids in the post-ablation setting and that using physical characteristics, in this case the observed half-life and pulse-height spectroscopy, can be useful in identifying the radio-contaminant.

Detection of deletion/insertion polymorphism profiles from single human hair shafts.

Hair is a frequently encountered biological evidence in personal identification. The amount of nuclear DNA that can be extracted from a single strand of rootless hair is most limited, making the detection of short tandem repeat (STR) polymorphisms difficult. To overcome these limitations, deletion/insertion polymorphisms (DIP) as a new type of genetic marker have shown their benefits in detecting low-copy-number DNA. The Investigator DIPplex kit contains 30 biallelic autosomal DIP and amelogenin. The analysis of DIPs combines the advantages of both STR and single nucleotide polymorphism analyses. Thus, this study aimed to detect the DIP distribution of individual hair shafts from individuals. DNA was extracted from the shaft of fresh, aged, and shed hair. After DNA was evaluated, the DIP profiles were detected by capillary electrophoresis. The results indicated that the amount of DNA extracted from hair roots was much higher than that from the hair shafts in the same individual for all samples. The degradation index values of DNA from the aged hair shafts were highest. It is classified to be "mildly degraded." Compared with their hair roots, the full DIP profiles were detected for fresh hair, 70% for aged hair, and 92% for shed hair. Contrarily, except for fresh hair shafts, only three STR loci of the aged and shed strands of hair could be genotyped using AmpFlSTR MiniFiler PCR Amplification Kit. These results indicate that the detection of DIP profile is an effective tool for personal identification from hair shafts, including aged hair.

Direct Ultratrace Detection of Lead in a Single Hair Using Portable Electromagnetic Heating Vaporization-Atmospheric Pressure Glow Discharge-Atomic Emission Spectrometry.

In this paper, the first demonstration of direct ultratrace determination of lead in a single human hair by direct current-atmospheric pressure glow discharge-atomic emission spectrometry (DC-APGD-AES) coupled with electromagnetic heating vaporization (EMV) was described. Only the ultramicro mass of a human hair sample (about 0.15 mg, often a single human hair) was required during the analysis, and fast detection was implemented without tedious pretreatment processes, such as grinding and digestion. A limit of detection (LOD) of 30.8 μg kg-1 (4.8 pg) for Pb was obtained under optimized conditions, which was even equivalent to that of conventional LA-ICP-MS/ETV-ICP-MS/GFAAS. EMV-APGD-AES, meanwhile, can facilitate miniaturization and portability with low power and small size. The accuracy and practicality of the method were verified by the analysis of certified reference materials (CRMs) GBW09101b (human hair) and human hair samples from three volunteers. A simple, efficient, and low-cost method for detecting Pb in human hair has been developed.

Alternative LC-MS/MS Platforms and Data Acquisition Strategies for Proteomic Genotyping of Human Hair Shafts.

Protein is a major component of all biological evidence. Proteomic genotyping is the use of genetically variant peptides (GVPs) that contain single-amino-acid polymorphisms to infer the genotype of matching nonsynonymous single-nucleotide polymorphisms for the individual from whom the protein sample originated. This can be used to statistically associate an individual to evidence found at a crime scene. The utility of the inferred genotype increases as the detection of GVPs increases, which is the direct result of technology transfer to mass spectrometry platforms typically available. Digests of single (2 cm) human hair shafts from three European and two African subjects were analyzed using data-dependent acquisition on a Q-Exactive Plus Hybrid Quadrupole-Orbitrap system, data-independent acquisition and a variant of parallel reaction monitoring (PRM) on an Orbitrap Fusion Lumos Tribrid system, and multiple reaction monitoring (MRM) on an Agilent 6495 triple quadrupole system. In our hands, average GVP detection from a selected panel of 24 GVPs increased from 6.5 ± 1.1 and 3.1 ± 0.8 using data-dependent and -independent acquisition to 9.5 ± 0.7 and 11.7 ± 1.7 using PRM and MRM (p < 0.05), respectively. PRM resulted in a 1.3-fold increase in detection sensitivity, and MRM resulted in a 1.6-fold increase in detection sensitivity. This increase in biomarker detection has a functional impact on the statistical association of a protein sample and an individual. Increased biomarker sensitivity, using Markov Chain Monte Carlo modeling, produced a median-estimated random match probability of over 1 in 10 trillion from a single hair using targeted proteomics. For PRM and MRM, detected GVPs were validated by the inclusion of stable isotope-labeled peptides in each sample, which served also as a detection trigger. This research accomplishes two aims: the demonstration of utility for alternative analytical platforms in proteomic genotyping and the establishment of validation methods for the evaluation of inferred genotypes.

Comparison of the Structural Elasticities for Tensile and Bending Deformations of a Single Human Hair

Comparison of the Structural Elasticities for Tensile and Bending Deformations of a Single Human Hair

Structural elasticity for tensile deformation of a single human hair and the comparison with it for the bending deformation

Human hair is a multi-layered structure, which consists of the inner medulla, middle cortex, and outer cuticle. Therefore, the mechanical properties of the hair are related not only to the Young's modulus of each layer but also to the internal structures. Although the tensile test of a human hair has been performed elsewhere, the deformability of the hair for the tensile deformation is determined as the Young's modulus of the hair structure, which is similar to that of metals. In this paper, the structural elasticity of a single human hair for the tensile deformation, which expresses the deformability of a hair by tension without being dependent on external dimensions and shape, is defined based on the theoretical model, and is measured by performing the tensile test under the digital microscope observation. The values of the structural elasticity for the tensile deformation of the hair samples collected from healthy persons are compared with the values obtained for bending deformation. The structural elasticity for the tensile deformation of the hair sample is found to be lesser than that of the bending deformation, and this is verified to be always valid provided the Young's modulus of the outer cuticle is greater than that of the middle cortex.

Detection of single human hairs with a terahertz nonlinear quantum cascade laser.

We report the demonstration of imaging of a single human hair with a terahertz quantum cascade laser (THz-QCL) source based on intracavity difference-frequency generation. A single human hair whose diameter was about 100 µm was detected using the THz-QCL source operating at 240 K, of which the THz beam had a linear polarization. The results show that the THz image of a human hair clearly depends on the polarization direction of the THz beam. The THz QCL sources that are capable of room temperature operation will be useful for detection of small foreign objects like human hairs.

Optimal processing for proteomic genotyping of single human hairs

The use of hair evidence for human identification is undergoing considerable improvement through the adoption of proteomic genotyping. Unlike traditional microscopic comparisons, protein sequencing provides quantitative and empirically based estimates for random match probability. Non-synonymous SNPs are translated as single amino acid polymorphisms and result in genetically variant peptides. Using high resolution mass spectrometry, these peptides can be detected in hair shaft proteins and used to infer the genotypes of corresponding SNP alleles. We describe experiments to optimize the proteomic genotyping approach to individual identification from a single human scalp hair 2 cm in length (∼100 μg). This is a necessary step to develop a protocol that will be useful to forensic investigators. To increase peptide yield from hair, and to maximize genetically variant peptide and ancestral information, we examined the conditions for reduction, alkylation, and protein digestion that specifically address the distinctive chemistry of the hair shaft. Results indicate that optimal conditions for proteomic analysis of a single human hair include 6 h of reduction with 100 mM dithiothreitol at room temperature, alkylation with 200 mM iodoacetamide for 45 min, and 6 h of digestion with two 1:50 (enzyme:protein) additions of stabilized trypsin at room temperature, with stirring incorporated into all three steps. Our final conditions using optimized temperatures and incubation times increased the average number of genetically variant peptides from 20 ± 5 to 73 ± 5 (p = 1 × 10−13), excluding intractable hair samples. Random match probabilities reached up to 1 in 620 million from a single hair with a median value of 1 in 1.1 million, compared to a maximum random match probability of 1 in 1380 and a median value of 1 in 24 for the original hair protein extraction method. Ancestral information was also present in the data. While the number of genetically variant peptides detected were equivalent for both European and African subjects, the estimated random match probabilities for inferred genotypes of European subjects were considerably smaller in African reference populations and vice versa, resulting in a difference in likelihood ratios of 6.8 orders of magnitude. This research will assure uniformity in results across different biogeographic backgrounds and enhance the use of novel peptide analysis in forensic science by helping to optimize genetically variant peptide yields and discovery. This work also introduces two algorithms, GVP Finder and GVP Scout, which facilitate searches, calculate random match probabilities, and aid in discovery of genetically variant peptides.

Polarized Dermoscopy Facilitates Diagnosis and Treatment of Plantar Pseudohirsutism

Background. Plantar cutaneous conditions are the most common causes of foot discomfort limiting ambulation. Identification of indwelling foreign bodies is greatly facilitated by dermoscopy, allowing early detection of the character of the underlying pathological etiology. Furthermore, polarized dermoscopy provides ideal conditions of illumination and three- dimensional visualization of the involved site, without direct contact with the cutaneous surface. This unprecedented report describes its implementation for a solitary hair implanted into plantar skin. Case Presentation. A patient presented with localized plantar discomfort diagnosed as a soft tissue reaction to an embedded single human hair, folded and rooted inside the epidermis. Under magnified vision the phenomenon was characterized, the hair was extracted, the source was manipulated with a hypodermic needle and the lesion was removed with ensuing complete resolution. Conclusions. Previous reports of hair slivers embedded inside the skin were attributed to barbers or animal grooming and the treatment was dictated by the severity of the complications. In this relatively mild case the intervention was greatly facilitated by therapeutic dermoscopy. Therapeutic dermoscopy is advocated for use to evaluate and treat many diverse body surfaces, especially the plantar skin as it raises the likelihood of successful treatment of embedded foreign bodies. Precisely how a single hair may become lodged into normal plantar skin remains to be explained

単一毛髪の引張特性に及ぼす試験条件の影響と光学顕微鏡による引張変形中のキューティクルのその場観察

単一毛髪の引張特性に及ぼす試験条件の影響と光学顕微鏡による引張変形中のキューティクルのその場観察

Effects of cosmetic treatments on the morphology, biotribology and sensorial properties of a single human hair fiber

Human hair has a complex multi-scale structure that is extremely sensitive to several external factors. Hair fiber has three compartments: cuticle (scales), cortex and medulla.In the everyday life, hair experience important mechanical and chemical solicitations, such as smoothing, combing, drying and even washing, which can induce cracks in the cuticle. These damages diminish the mechanical properties of the cortex and contribute to a decrease in the brightness and softness of the hair.In the present article, the effects of different cosmetic treatments: bleaching, coloring and smoothing (with different temperatures) have been explored. Firstly, the morphology of hair was measured by interferometry. A multi-scale roughness characterization was performed by applying continuous wavelet transform. This method quantified the arithmetic mean of the surface topography at each wave length and permitted observing the evolution of the cuticle morphology before and after treatment. Secondly, a patented haptic tribometer system was used to measure the friction coefficient and acoustic vibrations generated during the tribological test. Previous results have shown that vibrations are related to the softness of the hair surface.The results show that all the treatments change the morphology and biotribology of hair by damaging the hair cuticle. These changes impact the sensorial properties of hair. In particular, the morphology of colored and bleached hair, compared to virgin one, is strongly modified: the scales are less defined, and the roughness is increased. These morphological modifications are correlated with an increase of the friction coefficient of around 50%, and acoustic vibratory level of around 2%, indicated a decrease of the sensorial properties. The hair fiber becomes rougher, dull and less soft. On the contrary, thermomechanical treatments of previously damaged hair, impact the morphology and biotribology of hair differently. The cuticle scales are flattened and the values of the friction coefficient and acoustic vibratory level decrease to reach the virgin hair values. Thus, the hair fiber seems to be smoother, brighter and softer.In conclusion, these results are essential for understanding the impact of different solicitations on the physical and sensorial properties of hair.

Intrinsic activation of cell growth and differentiation in ex vivo cultured human hair follicles by a transient endogenous production of ROS

The emerging variety of signalling roles for ROS in eukaryotic cells and tissues is currently a matter of intense research. Here we make use of ex vivo cultured single human hair follicles as an experimental model to demonstrate that a transient production of non-lethal endogenous ROS levels in these mini-organs promotes efficiently the entry into the growth phase (anagen). The stimulatory process implicates the specific activation of the hair follicle stem cell niche, encompassing the induction of stem cell differentiation markers (Ck15), overall cell proliferation and sustained growth of the tissue associated with expression of gen targets (Ccnd1) concomitant with the inhibition of Wnt signaling antagonists and repressors (Dkk1, Gsk3β) of Wnt signaling. As a whole, this observation indicates that, once activated, ROS signalling is an intrinsic mechanism regulating the hair follicle stem cell niche independently of any external signal.

On the difference in the deformability of a single human hair for tensile and bending

On the difference in the deformability of a single human hair for tensile and bending

Synthetic cannabinoid isomers characterization by MALDI-MS3 imaging: Application to single scalp hair

New designer drugs, as synthetic cannabinoids (SCs), continuously appear on the market and are booming due to their cannabis-like effect. New generation of smokable SCs, structurally dissimilar from Δ9-tetrahydrocannabinol (THC), have isomers with distinguishable pharmacokinetic parameters and therefore different in vivo effects. The isoforms are misidentified using conventional techniques such as gas or liquid chromatography coupled to mass spectrometry - or tandem mass - spectrometry. The aim of this study was to differentiate three positional isomers (JWH-007, JWH-019 and JWH-122) in single human hair samples, which store numerous substances revealing a way of life and consumption style.Matrix-assisted laser desorption/ionization (MALDI) combined with imaging is an innovative and powerful tool used since few years, especially in forensic research. Herein, we propose an innovative method to monitor the drugs of abuse consumption through direct mapping of the compounds with a high spatial distribution in human hair samples, by state-of-art imaging MALDI-MSn. Three positional SC isomers (JWH-007, JWH-019 and JWH-122) were analysed using high and low fragmentation energy and the resulting MS/MS and even MS3 spectra differentiated the SCs. The MALDI-MS/MS and MS3 imaging was performed on hair soaked in a mixture of the three SCs as well as on hair from self-reported SC user, proving the potential of the technique for a forensic use. Keeping in mind that spatial distribution of organics from whole hair remains a challenge, the described methodology is a very promising analytical tool to probe the consumption of complex drugs and obtain correlation with its origin.

Analysis of cosmetic residues on a single human hair by ATR FT-IR microspectroscopy

In this work, ATR FT-IR spectra of single human hair and cosmetic residues on hair surface are successfully collected using a homemade dome-shaped Ge μIRE accessary installed on an infrared microscope. By collecting ATR spectra of hairs from the same person, the spectral patterns are identical and superimposed while different spectral features are observed from ATR spectra of hairs collected from different persons. The spectral differences depend on individual hair characteristics, chemical treatments, and cosmetics on hair surface. The “Contact-and-Collect” technique that transfers remarkable materials on the hair surface to the tip of the Ge μIRE enables an identification of cosmetics on a single hair. Moreover, the differences between un-split and split hairs are also studied in this report. These highly specific spectral features can be employed for unique identification or for differentiation of hairs based on the molecular structures of hairs and cosmetics on hairs.

Determination of arsenic and lead in single hair strands by laser ablation inductively coupled plasma mass spectrometry

The purpose of this study was to develop matrix-matched hair standards and a LA-ICP-MS technique for determination of the As and Pb in a single human hair using single spot scan mode. These results could subsequently be used to infer when the element entered the body. This study was conducted in two parts. First, a method was developed and validated for the elemental analysis of hair by LA-ICP-MS. A calibration strategy in LA-ICP-MS was developed using prepared matrix-matched laboratory hair standards doped with analytes of interest at a defined concentration. The use of hair strand standards enables calibration curves to be obtained by plotting the analyte ion (M+) intensity normalized to34S+(the ratio M+/34S+) as a function of the concentration determined by ICP-MS of the acidic digests. The linear correlation coefficients (R2) of the calibration curves for the analytes As and Pb were typically between 0.9970 and 0.9998, respectively. Second, an actual hair was measured using the developed method. The spatial distribution of As along the hair was observed in a hair sample from a leukaemia patient treated with arsenic trioxide (As2O3). The actual and estimated times over which the drug entered the body were compared and discussed.