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Objective: With the constant upgrading of healthcare concepts, silicone‐free hair products have attracted more attention among consumers. In the present study, transparent silicone‐free shampoo containing proteins was successfully fabricated by mixing mild non‐sulphate surfactants, compound cationic conditioners, natural silicone oil substitutes, protein conditioners, thickeners, and other auxiliary ingredients. The effects of the type of surfactants, hair conditioners and thickeners, the type and content of proteins, and the mass ratio of compound proteins on the hair foaming performance, hair grooming performance, and penetration performance were investigated. Methods: The basic formulation framework for transparent silicone‐free shampoo was established at first. Then, various hydrolyzed proteins were further added to the basic formulation in the form of single use or compound use to prepare transparent silicone‐free shampoo containing different proteins. The morphology of hair samples and penetration of protein in hair were evaluated with a scanning electron microscope and laser confocal fluorescence microscopy, respectively. And the hair grooming performance was also determined by a dynamic combing tester. Results: The compound proteins of Croquat WKP PE‐LQ‐WD and Gluadin® Kera‐PLM with mass ratios of 1:9 and 1:1 at 2 wt% total protein content added to the silicone‐free shampoo brought a higher contact angle and a lower frictional coefficient than commercial silicone‐free shampoo without proteins. In addition, the compound proteins also have the dual effect of adsorbing the hair surface and penetrating deep into the interior of the hair. Conclusion: The combination of cationic modified hydrolyzed protein (e.g., Croquat WKP PE‐LQ‐WD) and hydrolyzed protein with low molecular weight (e.g., Gluadin® Kera‐P LM) at an appropriate mass ratio exhibited a strong synergistic effect on hair conditioning properties. It could provide a significant reference for developing silicone‐free hair products with more benefits. [ABSTRACT FROM AUTHOR]

Animal hair examination may provide valuable information on forensic investigations. However, there are limited data on the hair histology of Indonesian mammals for serving as a database for identification. The present study provides histological analyses of the dorsal guard hairs of the Indonesian Suidae species Sus scrofa, S. barbatus, S. verrucosus and S. celebensis, which were examined from the collections of Museum Zoologicum Bogoriense, National Research and Innovation Agency. Comparative analysis was performed by light and scanning electron microscope. Different features of each animal species' hair were identified based on the morphology, cuticle scale pattern, type of medulla, pigmentation and cross-section characteristics. The results show that the cuticle scale pattern is an irregular wave in all species. The cuticle scale margin is rippled, and the distance between scales is close. The hair medulla is amorphous in all species. The hair pigmentation is yellowish-reddish in all species, but no pigmentation of hair is found in S. verrucosus. The cross-section shape of the hair shaft is different in all Indonesian Suidae species, which can be used for identifying the species of Indonesian Suidae. [ABSTRACT FROM AUTHOR]

In this work, n‐alkyl chitosan (N‐CTS) was obtained by alkylation modification of chitosan with n‐butylaldehyde using Schiff alkali method. The etherifying agent 3‐chloro‐2‐hydroxypropyl triethylammonium chloride (CHPTAC‐ethyl) was synthesized from triethylamine and epichlorohydrin. The N‐CTS and CHPTAC‐ethyl were etherized to finally synthesize n‐alkyl quaternary ammonium chitosan (N‐CCTS). Scanning electron microscope, X‐ray diffractometer, Fourier transform infrared, X‐ray photoelectron spectroscopy, and 13CNMR were used to characterize the surface morphology and chemical structure. Viscosity method and spectrophotometry were used to determine its physical and chemical properties. The etherification reaction mechanism was studied systematically and the influence of reaction conditions on the degree of substitution and solubility of N‐CCTS was investigated. The minimum inhibitory concentration (MIC) of N‐CCTS against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was both 0.15 g/L, which was superior to the MIC value of natural chitosan. N‐CCTS was used to finish rabbit hair fabric with citric acid as cross‐linking agent and sodium hypophosphite as catalyst. The antibacterial and washing resistance of the product were investigated. After 25 times of washing, the antibacterial rate of N‐CCTS against E. coli and S. aureus remained stable at about 90%, and the antibacterial rate was higher than that of N‐CTS and natural chitosan, and it was a kind of natural polymer long‐acting antibacterial finishing agent for rabbit hair fabric. [ABSTRACT FROM AUTHOR]

With increasing interest in hairstyles and hair color, bleaching, dyeing, straightening, and curling hair is being widely used worldwide, and the chemical and physical treatment of hair is also increasing. As a result, hair has suffered a lot of damage, and the degree of damage to hair has been measured only by the naked eye or touch. This has led to serious consequences, such as hair damage and scalp diseases. However, although these problems are serious, there is little research on hair damage. With the advancement of technology, people began to be interested in preventing and reversing hair damage. Manual observation methods cannot accurately and quickly identify hair damage areas. In recent years, with the rise of artificial intelligence technology, a large number of applications in various scenarios have given researchers new methods. In the project, we created a new hair damage data set based on SEM (scanning electron microscope) images. Through various physical and chemical analyses, we observe the changes in the hair surface according to the degree of hair damage, found the relationship between them, used a convolutional neural network to recognize and confirm the degree of hair damage, and categorized the degree of damage into weak damage, moderate damage and high damage. [ABSTRACT FROM AUTHOR]

This study focuses on the repair of damaged hair with the joint use of transglutaminase (TG enzyme) and keratin. We first prepared a TG-keratin repair solution with reasonable wool keratin and TG enzyme concentration, and used the soaking process to repair the damaged hair so as to modify protein fibers. We, then, measured the alkali solubility, fracture stress and strain, and swelling rate of the hair samples, before and after the treatment. The results showed that after treatment, samples' alkali solubility reduced from 16.14% to 4.92%, fracture stress increased from 0.832 N to 1.668 N, fracture strain arose from 8.81 mm to 10.17 mm, and swelling rate drops from 38.34% to 2.34%. Both Fourier transform infrared and X-ray diffraction spectroscopies further indicated that combined treatment with keratin and TG enzyme had significant repair effect on the damaged sites, where proteins were exposed with more amide bonds, higher crystallinity, increased percentage of crystalline area over the entire fiber area, and strengthened crosslink activities. Observation under both scanning electron microscope and atomic force microscope revealed smoother surface and fewer warped scales on the surface of hairs after combined treatment with keratin and TG enzyme. To our best knowledge, this is the first application of enzyme technology in damaged hair repair. It opens up a new research direction for green, environmentally friendly, and efficient biological hair care and will play a pivotal role in the application of various protein-based materials. [ABSTRACT FROM AUTHOR]

Archaeological studies always seek for understanding history and draw right pictures about the life in the past in the different civilizations. Consequently, varieties of sciences are applied in these studies to extract the historical information. Hence this study investigated hair samples that were taken from four royal mummies with the aim of obtaining reliable information about the materials used in embalming, health status of these mummies, their age, and hair color that affects its composition. A variety of analytical techniques were applied in this study; digital microscope, polarizing optical microscope, environmental scanning electron microscope coupled with energy-dispersive X-ray unit, Fourier transform infrared spectroscopy, gas chromatography, and Raman spectroscopy analysis. The results showed the significance of hair in biomonitoring health status and determining age. Besides, it was proved that mastic resin has been used in embalming as early as the Second Intermediate Period especially for royal mummies. [ABSTRACT FROM AUTHOR]

Chemical signals play a decisive role in communication in many mammal species. In red deer (Cervus elaphus), the dark ventral patch has recently been described as a male chemical signal involved in intrasexual competition. Morphological specializations of the hair of this area might contribute to retaining the volatile compounds found here. In this study, we examined differences in the ultrastructure between hair associated with the dark ventral patch and hairs from the dorsolateral region of the body as a control. We obtained a gallery of images from a scanning electron microscope to study the possible variation in the detailed anatomy as well as the surface and pattern of cuticular scales of hairs of the two body regions examined. In addition, we used a 2D‐3D microscope to measure hair diameter (thickness) and the shape and size of the cuticular scales. We found that the hairs of the dark ventral patch were narrower than those from the dorsolateral region. We also found a different cuticular scale pattern of the dark ventral patch hairs, suggesting a possible specialization for the retention of compounds associated with this chemical signal. Moreover, some intersexual differences in hair morphology also support this idea. This study shows, for the first time, the differentiation of hairs related to the dark ventral patch, which contributes to our better understanding of this chemical communication in red deer. [ABSTRACT FROM AUTHOR]

Background: Acid straightener products are widely used, and it can cause changes in the hair shaft properties. The pH value of these products established by ANVISA (Brazil's National Health Surveillance Agency) as secure is above 2.0. However, the industries are interested in working at lower pH values in order to increase the straightening effect. Unfortunately, there are a lot of products in the market with pH value under the permitted. Objective: Analyze two different pH values (1.0 and 2.0) of acid straightener formulation and the influence of this difference in the hair shaft properties. In order to provide information to professionals as cosmetologists, dermatologists, and hairdressers. Methods: Combing and colorimetric analyses, tensile strength, differential scanning calorimetry (DSC), environmental scanning electron microscope (ESEM), and tryptophan content. Results: The tresses treated at pH 1.0 had a better result in the straightening capacity, improving the combing test in 59.4%, while those at pH 2.0, only in 33.0% compared with virgin hair. However, the tensile strength, at pH 1.0 decreased by 16.0% and 9.0% to the pH 2.0. In addition, the tryptophan content was lower in the tresses treated with formulation at pH 1.0. The DSC analysis showed impairment in the straightened tresses. The images by ESEM, indicated a possible formation of a film around the fiber. Conclusions: It was possible to conclude that the pH value interferes in the hair shaft properties. Tresses treated with pH 1.0 had more modifications than tresses treated with pH 2.0. [ABSTRACT FROM AUTHOR]

Drugs incorporated into hair are exposed to the environment, and cosmetic and chemical treatments, with possible decreases in their content. Knowledge concerning the effect of sunlight on drug content in hair can be helpful to forensic toxicologists, in particular, when investigating drug concentrations above or below pre-determined cut-offs. Twenty-eight authentic positive hair samples were selected which had previously tested positive for ethyl glucuronide (EtG). Washed hair were divided into two identical tufts, with the former exposed at 13,219 J/cm2 (300–800 nm spectrum of irradiance) for 48 h in a solar simulator, and the latter kept in the dark. Hair samples were extracted and analyzed by ultra performance liquid chromatography–tandem mass spectrometry. The percentage of photodegradation was calculated for EtG. In parallel, photodegradation processes of standard molecule dissolved in aqueous and organic solutions were studied. In 28 hair samples, positive for the targeted analyte, exposure to artificial sunlight induced an appreciable increase in EtG concentrations. The concentration range in the non-irradiated hair samples was 6.0–772.0 pg/mg, and 64.3% of samples exhibited an increase in post-irradiation samples, ranging from 7% to 255%. In seven cases, a decrease was observed ranging from −5.0% to −36.0%. Thus, either a decrease or an increase of EtG may be observed post-irradiation, depending on hair color and/or hair thickness. Because the denaturation status of hair fibers and the thickness of hair before irradiation could play a role, a scanning electron microscope study should be envisaged. [ABSTRACT FROM AUTHOR]

Summary: Background: Hair‐straightening treatments may involve the use of thermal devices, which potentially cause damages in the cuticle and cortex of the hair fibers. Particularly, the heat causes denaturation of the α‐keratin and the degradation of the components of the hair cortex. Objectives: The aim of this study was to evaluate the effect of heating on the cuticle and cortex of the Caucasian and Asian virgin hair by using heat iron flat. Methods: The effects of the heating in the tresses of Caucasian and Asian virgin hair were analyzed by thermogravimetry/differential scanning calorimetry‐Fourier transform infrared/mass spectrometry (TG/DSC‐MS/FTIR), protein loss analysis (PLA), Fourier transform infrared (FTIR‐ATR), and scanning electron microscope (SEM). Results: TG/DSC‐MS/FTIR results were: formation of the H2O between 25‐170°C and CO2, SCO and H2S from 200°C. Denaturation temperature = 237°C. Protein loss: Asian hair>Caucasian hair. Data presented statistically significant alterations, α = 5, P ≤ 0.05, n = 3. FTIR‐ATR: changes in the secondary structural conformation of the protein of hair cuticle. SEM: heat caused damage to hair cuticle. Conclusions: The results evidenced the importance of the control of temperature in the procedures involving heat. The damage caused by thermal devices showed be dependent of the ethnicity analyzed (Caucasian and Asian hair). [ABSTRACT FROM AUTHOR]

Nature is an amazing source of inspiration for the design of thermal insulation strategies, which are key for saving energy. In nature, thermal insulation structures, such as penguin feather and polar bear hair, are well developed; enabling the animals' survival in frigid waters. The detailed microscopy investigations conducted in this study, allowed us to perform microstructural analysis of these thermally insulating materials, including statistical measurements of keratin fiber and pore dimensions directly from high resolution Scanning Electron Microscope (SEM) images. The microscopy study revealed many similarities in both materials, and showed the importance of their hierarchically-organized porous structure. Finally, we propose the schematic configuration of a thermally-insulating structure, based on the penguin feather and polar bear hair. These optimized thermal-insulator systems indicate the road maps for future development, and new approaches in the design of material properties. We present the first detailed comparison of microstructures of penguin feather and polar bear hair for designing optimum thermal insulation properties. This unique study involves the measurement of the sizes of pores and fibers of these two keratin-based materials, including the investigation of their 3D arrangements. We revealed porosity interconnection, especially in polar bear hair, which is one of the key designs exhibited by thermal insulation materials. [ABSTRACT FROM AUTHOR]

We developed a pictorial atlas of 52 scanning electron microscope (SEM) images of hairs found on 12 mammalian game species commonly found in the South African lowveld. Guard hairs were taken from the dorsoscapular, scapular, sternal, or axillary regions of each animal; and bristle hairs, if present, were collected from the manes of animals of each species. These images, along with other diagnostic features of hairs, can be used as an identification system. Such a system is useful for ecological studies where identifying animal remains is necessary. [ABSTRACT FROM AUTHOR]

In this study, an aqueous extract of Morus alba (M. alba) was incorporated into hair hydrochar (HH) to enhance the anti- Staphylococcus aureus activity. The bacterial adsorption capacity of HH alone was tested using the modified TTC-DRA (dehydrogenase relative activity) assay and imaged with Scanning Electron Microscope (SEM). The loading efficiency, Fourier-transform infrared spectroscopy (FT-IR) analysis, and anti- S. aureus performance of M. alba extract (MAE) loaded hydrochar (HH+MAE) was investigated. Concentration-dependent inhibitions of HH and HH+MAE on S. aureus inoculated on the artificial skin surface were studied for the first time. In the agar well diffusion test, the highest inhibition zones (IZs) of HH and HH+MAE were 3.4 mm and 20.1 mm on S. aureus. The decrease in the number of S. aureus were 0.39 CFU/cm2, 0.42 CFU/cm2 and 0.49 CFU/cm2 at the 10 mg/mL, 20 mg/mL and 40 mg/mL of HH, respectively, while log reduction were 0.81 CFU/mL, 0.83 CFU/ cm2 and 1.1 CFU/ cm2 at the 10 mg/mL, 20 mg/mL, and 40 mg/mL of HH+MAE, respectively. The percent reduction (%) of S. aureus treated with 40 mg/mL of HH was found as 67.7%, while was 92.2% when treated with 40 mg/mL of HH+MAE (p < 0.05). As a result, the anti- S. aureus activity of HH containing bioactive components enriched with MAE extract was strengthened. HH+MAE can be suggested for use in the treatment of skin disorders in which S. aureus is dominant. [Display omitted] • M. alba aqueous extract was combined with high-efficiency hair hydrochar. • The anti- Staphylococcus aureus activity of the hydrochar enriched with the bioactive components of the M. alba was shown. • In vitro, S. aureus reduction was 92.2% when treated with 40 mg/mL of HH+MAE by creating artificial skin. • The highest decrease in the number of S. aureus was 1.1 CFU/cm2 at 40 mg/mL of HH+MAE. [ABSTRACT FROM AUTHOR]

A postmortem root band (PMRB) is a distinct microscopic feature that is postulated to occur in hair remaining in the follicle during the postmortem interval [1] (Petraco et al., 1998). The scientific validity of this premise has been highlighted in two recent high-profile criminal cases involving PMRBs [2,3] (State of Florida v. Casey Marie Anthony, 2008; People v. Kogut, 2005). To better understand the fundamental aspects of postmortem root banding, the microscopical properties of known PMRBs1 were characterized by light microscopy, and scanning electron microscope (SEM) imaging of microtomed sections of hairs showing root banding. The results from this study show that the appearance of the PMRB may be due to the degradation of the chemically labile, non-keratin intermacrofibrillar matrix (IMM) in the pre-keratin/keratogenous region of anagen hairs. In addition, this degradation is confined to the cortex of the hair, with no apparent damage to the layers of the cuticle. These results could provide valuable information for determining the mechanism of band formation, as well as identify a set of microscopic features that could be used to distinguish hairs with known PMRBs from similarly looking environmentally degraded hairs. [ABSTRACT FROM AUTHOR]

This study provides the first description, based on SEM imagery, of the hairy structures related to life on the water surface of two Alpine- Apenninic species belonging to the genus Velia: V. currens ( Fabricius, 1794) and V. gridellii Tamanini, 1947. In general, no relevant differences in the organization and form of these structures were found between the two species. Similarly, few differences were observed between males and females, and in comparison with the only congeneric with hairy structures thus far described, V. caprai Tamanini, 1947, confirming a substantial homogeneity within the subgenus Plesiovelia. The discovery of a double layer of microtrichia in both our species allowed us to detect them even in V. caprai, for which only a single layer was previously described. Finally, the presence of a structure corresponding to the male grasping comb was discovered in females of V. gridellii and is reported for the first time in the genus and in the Old World Veliinae. A similar structure was not identified in V. currens. This difference may be relevant for better understanding the relationships among species belonging to this genus. [ABSTRACT FROM AUTHOR]

Simple Summary: The western honey bee (Apis mellifera) is an important ecological pollinator that commercially and economically contributes billions of dollars of free services to our ecosystem. Having the basic knowledge to provide an effective and standardized measure of the trait and check the pollination effectiveness is very important. However, we are still lacking efficient methods that can significantly measure traits. In this study, we checked the morphological structure of hairs on all of the body parts of the western honey bee by using a scanning electron microscope (SEM); furthermore, we also described the slide preparation method to measure hair length, which could also be used for distinct invertebrates. We found two forms of long and short hairs along with five different types of branches. These branches are worthwhile in pollination effectiveness during holding and transporting pollen. The thoracic region is filled with long hairs with maximum branches, which suggests that the thorax in honey bees probably plays a significant role in pollination effectiveness. Bees play a very important role in pollination, especially western honey bees, which contribute upwards of billions of dollars concerning crop pollination. Hairiness plays an important role in pollination success by transporting pollen, and pollen intake, but there is a lack of detailed studies on the morphological mechanisms. The hairiness trait is barely discussed in pollinator trait analysis because of the lack of systematic techniques used to measure hairiness. This paper reports a novel method that is used to measure the hair length of different body parts of a western honey bee through a stereomicroscope equipped with live measurement module software. Scanning electron microscope (SEM) was used to update the knowledge regarding the hair structure of a western honey bee. We explained different types of hairs, hair branches, and their distributions on different body parts, which are discussed in detail. A positive correlation was found between hair length and the number of branches on all body parts. Five types of branches were observed, and these branches vary with different body parts. Our study provides sufficient details about the hair morphology of the western honey bee and a new methodology for measuring hair length. This methodology will improve the knowledge about understanding the pollination efficiency of the western honey bee. [ABSTRACT FROM AUTHOR]

In recent years, with the gradual development of medicine and deep learning, many technologies have been developed. In the field of beauty services or medicine, it is particularly important to judge the degree of hair damage. Because people in modern society pay more attention to their own dressing and makeup, changes in the shape of their hair have become more frequent, e.g., owing to a perm or dyeing. Thus, the hair is severely damaged through this process. Because hair is relatively thin, a quick determination of the degree of damage has also become a major problem. Currently, there are three specific methods for this purpose. In the first method, professionals engaged in the beauty service industry make a direct judgement with the naked eye. The second way is to observe the damaged cuticle layers of the hair using a microscope, and then make a judgment. The third approach is to conduct experimental tests using physical and chemical methods. However, all of these methods entail certain limitations, inconveniences, and a high complexity and time consumption. Therefore, our proposed method is to use scanning electron microscope to collect various hair sample images, combined with deep learning to identify and judge the degree of hair damage. This method will be used for hair quality diagnosis. Experiment on the data set we made, compared with the experimental results of other lightweight networks, our method showed the highest accuracy rate of 94.8%. [ABSTRACT FROM AUTHOR]

The cutting behaviour of beard hair has been investigated quantitatively and qualitatively. High speed cutting tests were conducted on beard hair samples using a purpose built cutting rig (provided by Gillette, UK) to determine the cutting forces. High speed digital video photography was used to record the cutting process. In parallel with these tests, low speed cutting tests were undertaken within a scanning electron microscope (SEM) to gain a better understanding of the cutting process. Results from the high speed cutting tests showed that the peak cutting stresses are influenced strongly by moisture (the cutting stress for ‘wet’ samples is reduced by about 30% as compared to dry samples) while the effects on the cutting stress of other variables (subject age, blade approach angle and sample ageing due to prolonged storage) appeared to be less noticeable. The angle of cut was affected by the distance of the initial contact point (between the hair and the blade) from the base of the hair with the line of cut shifting towards the hair axis with increasing distance from the base. Qualitative observations from video-recordings and still images taken during the cutting tests, conducted in-situ within the SEM as well as the high speed cutting rig, showed four main cutting mechanisms of hair, which are documented in this paper. The distance from the initial contact point to the base of the hair and the moisture level were the parameters which controlled the mechanism of failure. Qualitative observations of the sort reported here are a necessary pre-cursor to the development of finite element models to simulate a cutting operation. [ABSTRACT FROM AUTHOR]

This study was based on the records of baculum features, hair scale form, and karyotype of Taphozous nudiventris magnus. The baculum is a distinctive feature in separating this subspecies from T. n. kachhensis. The structure of the hair scale type examined by scanning electron microscope (SEM) was divaricate, dentate coronal at the tip, and varied from the tip of the hair to the base; it had a divergent, dentate coronal at the shaft and an appressed, repand coronal at the base. The diploid number (2n) and the number of autosomal arms (NFa) of T. n. magnuswere 42 and 64, respectively. [ABSTRACT FROM AUTHOR]

This article tests the crimped character of the opossum hair, making use of the curly elastic instrument. The result of the test is that the fiber of the opossum hair is short, the crispation number of the fiber is more than cashmere, but the elastic recovery rate is less than cashmere. Making use of the scanning electron microscope to survey the surface flake of the opossum hair and in the basis of comparing with fine wool and cashmere we analyze the scale structure of the opossum hair. The results of the test indicate that the surface flake of the opossum hair consists of indention, circularity, lamelliform, flakiness. Because of the hollowed areas of the opossum hair, the fiber has fine light-admitting quality in optical microscope. [ABSTRACT FROM AUTHOR]

The article focuses on the comparison of several microscopes. The author conducted a study using his blood cells and hair to see the advantages and disadvantages of different microscopes, which includes a confocal microscope, an atomic force microscope, a scanning electron microscope and a transmission electron microscope. He cites that the NanoScope IIIA, is not recommended for use in making a micrograph for big specimen. He adds that the difference between the microscopes also allowed them to see things that were not visible on other microscopes.

More than 20 hair strands obtained from several people are analyzed by non-invasive micro-proton induced X-ray emission (PIXE) for probing calcium and sulfur distribution and pattern. The sulfur content in woman's hair along the longitudinal axis shows a monthly rhythm whereas the level of Ca is much higher in the medulla core and exhibits a daily rhythm both in male and female hair. The Ca content gradually decreases from the tip to the root position in the shedding process and more Ca can be found in black hair compared to white hair. [ABSTRACT FROM AUTHOR]

Hair samples from patients with different ectodermal dysplasias; hypohidrotic ectodermal dysplasia, pachyonychia congenita, tricho-dento-osseous syndrome, tricho-rhino-phalangeal syndrome, and hypomelanosis of Ito were investigated using a scanning electron microscope. The hairs of the patients showed different structural abnormalities; twisted hairs, longitudinal grooves, trichorrhexis nodosa as well as variations in the hair caliber. Hair shaft abnormalities, as in our patients with tricho-dento-osseous syndrome, and hypomelanosis of Ito have so far not been described. [ABSTRACT FROM AUTHOR]

Following positive identification by the usual cytogenetic means of a newborn girl with a triploid chromosome complement (69.XXX), a sample of hair was analyzed with the scanning electron microscope. The results of the observation on triploid human hair were compared to data gathered from the hair of normal newborn boys and girls. Significant differences were found between triploid and diploid hairs in mean width, mean width between the free edges of the cuticular scales, and average number of cuticular scales. [ABSTRACT FROM AUTHOR]

The article focuses on the clinical importance of weathering in human hair. The clinical importance of weathering has been greatly increased by the recent popularity of wearing the hair long. With the scanning electron microscope it has been shown that apparently normal hair shafts show a progressive loss of cuticular scale pattern from root to tip. In man it is difficult to differentiate the effect of weathering alone from the combined effect of weathering and trauma inflicted for cosmetic purposes, since even the more uncouth seldom refrain completely from the use of a brush and comb.