Benefit of coconut-based hair oil via hair porosity quantification.

OBJECTIVE: The present study is intended to characterize the surfactant damage suffered by the hair cortex in routine washing and the mechanistic effect of Coconut Based Hair Oils (CBHO) to mitigate the damage. METHODS: Surfactants which diffuse into the hair structure solubilize protein moieties, leading to an increase in porosity and internal surface area as well as the pore volume. The changes in hair pores occurring in the hair cortex are measured by nitrogen sorption method in line with the Brunauer-Emmett-Teller (BET) theory. Single fiber tensile parameters were measured using Diastron MTT 175. Color protection was measured quantitatively using spectrophotometer as well as visual rating by trained panelists. RESULTS: The pore surface area data clearly show the benefit of introducing coconut-based hair oils (CBHO) into the hair by preventing increase in hair porosity. A statistically significant decrease in break stress and toughness were observed and the same were reversed by the application of CBHO. A pronounced color protection effect was also recorded with the application of CBHO. CONCLUSION: The porosity reduction effect seen with the use of CBHO is attributed to the CBHO molecules blocking the diffusion pathways in the endocuticle and the matrix part of the cortical cells, limiting protein surfactant interaction resulting in reduced solubilization and loss. Since, the color molecules are likely to be much smaller than the protein moieties, a pronounced color protection effect suggests that the penetrated CBHO molecules form a dense diffusion barrier in the matrix, cell membrane complex (CMC) and the endocuticle regions of hair - which are the main diffusion pathways out of hair. The study confirms the damage repair potential of CBHO and that it works by increasing the hydrophobicity of hair - both on the hair surface and in the cortex.

OBJECTIF: La présente étude a pour but de caractériser les dommages causés par les surfactants au cortex pilaire lors des lavages de routine et l'effet mécanique des huiles capillaires à base de noix de coco (CBHO) pour atténuer ces dommages. MÉTHODES: Les tensioactifs qui diffusent dans la structure du cheveu solubilisent les fractions de protéines, ce qui entraîne une augmentation de la porosité et de la surface interne ainsi que du volume des pores. Les modifications des pores du cheveu survenant dans le cortex pilaire sont mesurées par la méthode de sorption de l'azote, conformément à la théorie de Brunauer-Emmett-Teller (BET). Les paramètres de traction de la fibre unique ont été mesurés à l'aide du Diastron MTT 175. La protection de la couleur a été mesurée quantitativement en utilisant un spectrophotomètre ainsi qu'une évaluation visuelle par des panélistes formés. LES RÉSULTATS: Les données sur la surface des pores montrent clairement l'avantage d'introduire des huiles capillaires à base de noix de coco (CBHO) dans les cheveux en empêchant l'augmentation de la porosité des cheveux. Une diminution statistiquement significative de la contrainte de rupture et de la résistance a été observée, qui a été inversée par l'application de CBHO. Un effet prononcé de protection de la couleur a également été enregistré avec l'application de CBHO. LA CONCLUSION: L'effet de réduction de la porosité observé avec l'utilisation de CBHO est attribué aux molécules de CBHO bloquant les voies de diffusion dans l'endocuticule et la partie matricielle des cellules corticales, limitant l'interaction protéine surfactant résultant en une solubilisation et une perte réduite. Étant donné que les molécules de couleur sont probablement beaucoup plus petites que les parties protéiques, un effet prononcé de protection de la couleur suggère que les molécules CBHO pénétrées forment une barrière de diffusion dense dans la matrice, le complexe de la membrane cellulaire (CMC) et les régions endocuticulaires des cheveux - qui sont les principales voies de diffusion hors des cheveux. L'étude confirme le potentiel de réparation des dommages du CBHO et le fait qu'il agit en augmentant l'hydrophobie des cheveux - à la fois sur la surface du cheveu et dans le cortex.

Preliminary analysis of the distribution of water in human hair by small-angle neutron scattering.

Diffusion and distribution of water in hair can reveal the internal structure of hair that determines the penetration of various products used to treat hair. The distribution of water into different morphological components in unmodified hair, cuticle-free hair, and hair saturated with oil at various levels of humidity was examined using small-angle neutron scattering (SANS) by substituting water with deuterium oxide (D(2)O). Infrared spectroscopy was used to follow hydrogen-deuterium exchange. Water present in hair gives basically two types of responses in SANS: (i) interference patterns, and (ii) central diffuse scattering (CDS) around the beam stop. The amount of water in the matrix between the intermediate filaments that gives rise to interference patterns remained essentially constant over the 50-98% humidity range without swelling this region of the fiber extensively. This observation suggests that a significant fraction of water in the hair, which contributes to the CDS, is likely located in a different morphological region of hair that is more like pores in a fibrous structure, which leads to significant additional swelling of the fiber. Comparison of the scattering of hair treated with oil shows that soybean oil, which diffuses less into hair, allows more water into hair than coconut oil. These preliminary results illustrate the utility of SANS for evaluating and understanding the diffusion of deuterated liquids into different morphological structures in hair.

Corrigendum to "Indexing blood banking performance in India: A retrospective cross-sectional analysis of states and districts" [Dialogues in Health: Volume 3 (2023)-Article 100160].

[This corrects the article DOI: 10.1016/j.dialog.2023.100160.].

A study on impostor phenomenon, personality, and self-esteem of medical undergraduates and interns.

Introduction: Impostor phenomenon (IP) is a psychological experience where an individual considers their achievements to be fraudulent. IP in medical professionals is of paramount importance since it affects their self-confidence and communication skills. It has been associated with burnouts, low self-esteem, and neuroticism. Aim: This research aimed to study the prevalence of IP, personality traits, and self-esteem and to look at gender differences in medical undergraduate students and interns of an urban medical college along with the correlation of IP with personality traits and self-esteem in them. Methodology: An online survey via Google Groups was conducted among MBBS students and interns of a medical college after informed consent and ethics approval were received. Four hundred sixteen participants completed the survey questionnaire which included demographic variables along with the the Clance Impostor Phenomenon Scale, the Big Five Inventory, and the Rosenberg Self-Esteem Scale. Results: IP was found in 236 (56.7%) students and interns. Personality domain mean scores were extraversion (26.4 ± 5.12), agreeableness (33.5 ± 5.4), conscientiousness (29.9 ± 5.7), neuroticism (21.6 ± 5.7), and openness (35.1 ± 4.9). The self-esteem mean score was 18.37 ± 6.14; only 16.11% had high self-esteem. Interns and first-year MBBS students scored higher on IP and low on self-esteem among all groups. Significant gender differences were seen in females on agreeableness, conscientiousness, and neuroticism as compared to the males. IP negatively correlated with self-esteem, extraversion, agreeableness, and conscientiousness and positively with neuroticism. Conclusion: This study throws some light on the IP experiences of medical undergraduates which have not been extensively researched in India.

Indexing blood banking performance in India: A retrospective cross-sectional analysis of states and districts.

Background: Multiple international assessments have highlighted gaps in blood banking globally. However, there is a dearth of subnational assessments. We applied a thematic framework with multiple composite indices to assess blood bank performance across Indian states and districts. Methods: In this retrospective cross-sectional analysis, data for 2493 blood banks in 35 states/union territories (UTs) and 616 districts was extracted from the National Blood Transfusion Council for 2016. The framework involved seven themes (accreditation, ownership, safety, volume, infrastructure, regulation, and workforce) with several indicators nested under them. Composite thematic indices and an overall index (0-100, with 100 being the best performance) were constructed using the adjusted Mazziotta-Pareto index method that can provide composite indices that are partially non-compensatory and easily interpretable. Results: The state-level median [interquartile range] value of the overall index was 59.61 [46.35, 71.67]. Chandigarh had the highest values for safety, regulation, workforce, and ownership indices, Maharashtra for volume and infrastructure indices, and Manipur for accreditation index. Districts in southern and western states performed well on the overall index with inter- and intra-state variations for themes. District-level correlations depicted positive associations among indices with the strongest correlation between ownership and accreditation indices (n=616, R=0.92, p<0.001). Conclusion: Blood banking in India is fragmented, with variations in themes across geographies. The northern and northeastern states require more attention for volume, accreditation, infrastructure, and ownership. While the southern and western-central regions need to prioritize safety. The framework with thematic indices, when applied to routine data, can be useful for monitoring and evaluation to decide local policies and resource allocations.

Incidence of Early Adverse Events Following Covishield (ChAdOx1 nCoV-19) Vaccination: A Prospective Study.

Background: Minor adverse event following immunizations (AEFIs) are often underreported and self-treated. This study aimed to collect information regarding any and every probable adverse event experienced by the recipient of Covishield vaccine up to 10 days following the first and second dose of vaccine. To find the incidence of minor adverse events following Covishield vaccination; draw an association between adverse events and individuals' demographic factors and comorbidities; and report new adverse events, if any. Materials and Methods: A descriptive observational study was conducted among 409 participants randomly sampled from the Vaccination Centre at a Tertiary Care Hospital, Mumbai. Participants were followed up post their first and second doses to enquire about adverse events. Results: Most commonly reported adverse events included injection site pain, tenderness, chills, fatigue, fever, and myalgia. Females reported more adverse events compared to men (p < 0.05). Younger individuals (18-24) experienced adverse events more as compared to individuals above 40 years of age (p < 0.005). Reported adverse events were lesser after the second dose in comparison with the first dose. Few participants reported dysgeusia. Conclusions: Covishield vaccination has a mild AEFI profile, most commonly: injection site pain, tenderness, chills, and fatigue. It is hoped that the findings of this study will dispel anxiety around the adverse events of vaccination and reduce any persisting vaccine hesitancy. Effective communication with the population on vaccination will enable individuals to make educated and informed decisions.

Reduction-induced surface modification of human hair.

A microfluorometric method has been developed to characterize lipid removal or "delipidation" of the human hair cuticula during light exposure and chemical grooming processes such as oxidation (bleaching) and reduction. In the case of photochemical and chemical oxidation, lipid removal ("delipidation" of the F-layer or lipid-layer) from the outer beta-layer of the exposed scale faces and generation of cysteic acid groups occurs. This "delipidation," which ultimately results in "acidification" of the scale faces, leading to a change in surface chemistry from hydrophobic to hydrophilic, can be detected and quantified by microfluorometry by tagging, e.g., with the cationic fluorochrome Rhodamine B. In the case of reduction, similar tagging of the acid sites on the scale faces is possible, but this time, Rhodamine B reacts with the mixed disulfide containing a carboxyl group that will be ionized above a pH of about 4. In addition to this, we have shown by microfluorometric scanning that the negative charges generated in the cuticle surface can be used to bind low-molecular-weight quaternary conditioners. This process can be considered as "relipidation" or "refatting" of the scale faces. We have shown in earlier studies (1) that this entire process of oxidation-induced "delipidation" and subsequent "relipidation" of the acidic scale faces with a cationic conditioning molecule can also be reliably quantified by X-ray photoelectron spectroscopy (XPS). Furthermore, single-fiber wettability scanning using the Wilhelmy technique, which is highly sensitive to any changes in surface chemistry, is well-suited to detect and characterize treatment-induced changes in the chemical nature of the hair surface from hydrophobic to hydrophilic.

Hair breakage during combing. IV. Brushing and combing hair.

During combing of hair, longer fiber breaks (>2.5 cm) occur principally by impact loading of looped crossover hairs, while short segment breaks (<2.5 cm) occur primarily by end wrapping. Brushing provides breakage similarly but with a higher ratio of long-to-short segment breaks, and the ratio of long-to-short segment breaks (L/S) is a good way to follow these two pathways of breakage under different conditions. For example, bleaching hair, a longer comb stroke, increasing fiber curvature, wet combing versus dry combing, and brushing versus combing all provide for an increase in long segment breaks and this ratio, with the largest effect produced by brushing.

Hair breakage during combing. III. The effects of bleaching and conditioning on short and long segment breakage by wet and dry combing of tresses.

A recent publication (1), provided evidence for two types of hair breakage during combing, short segment breakage (approximately less than 1.27 cm) and longer segment breakage. We have confirmed these results and refined the separation distance between short and long segment breakage at about 2.54 cm. Furthermore, chemical bleaching increased both short and long segment breakage while a commercial hair conditioner decreased both types of breakage. Whether the hair is chemically bleached or conditioned, for dry combing, short segment breakage increases with increasing comb strokes, that is, short segment breakage increases as combing damages the ends of the hair, however, long segment breakage does not increase with increasing comb strokes. Wet combing provided a decrease in short segment breakage and an increase in long segment breaks, but no increase in breakage with increasing comb strokes. Mechanical combing of tresses shows similar results qualitatively, however the variance was too large and adjustments need to be made to provide for a larger number of broken hairs to bring the mechanical and hand combing results in line. For dry combing, as the comb descends through the hair, hairs above it are made parallel and those beneath are either made parallel or knot by, hairs looping around other hairs or hairs looping around comb teeth and other hairs several cm between the comb and the hair tips. As the comb advances through the looped/knotted hairs long breaks occur or as the comb descends near the tips wrapped ends can result. End wrapping by inertia & possibly static charge produces short segment breaks which are more severe if the hair is cut at 90 degrees versus a tapered cut. For wet combing, clumping of hairs by a capillary action produces fewer short segment breaks, by reducing end wrapping: however, crossed hair interactions occur & because of higher friction more severe snags arise higher up in the tress, and lower hair breaking load due to plasticization by water, producing a larger number of long segment breaks. The very best practical way to evaluate hair strength is by counting the actual number of short and long segment breaks and by considering both wet and dry combing.

Diffraction of light by the cuticle structure of hair.

Under a microscope, hair looks like a surface relief grating with an irregular sawtooth profile. Using scalar diffraction theory, we model what has been, until now, assumed to be a specular peak in the light scattering data. Diffraction efficiencies are calculated as a function of cuticle thickness. Convolution with apertures and Gaussian processes yields a picture that is consistent with the observed position and structure of the "specular" peak. When the cuticle thickness fails to satisfy the blaze condition, the scattered light is distributed amongst multiple diffraction orders giving rise to a complex central structure.

Tensile properties of twisted hair fibers.

Hair is routinely twisted during grooming processes, which can cause tangles and lead to breakage of hair fibers. To evaluate the damage caused by twisting hair, the tensile stress-strain properties of single twisted hair fibers were measured by two different experimental procedures: (A) twist at constant length, followed by extension to break (without untwisting); and (B) twist and untwist at constant length, followed by extension to break. In procedure (A), the strength, extension, and initial modulus decreased with increase in twist factor, whereas in procedure (B), the strength and extension did not significantly change from control values, although the initial modulus decreased with increase in twist factor. Furthermore, the degree of recovery from torsional deformation was studied by a variant of procedure (B), where the fiber after untwisting was relaxed for 5 and 10 minutes, respectively, prior to extension to break. The major conclusion from this study was that at low and moderate twist levels, the tensile mechanical properties of human hair are recoverable.

Failure of intercellular adhesion in hair fibers with regard to hair condition and strain conditions.

Although adhesion failure in hair fibers can occur inside cells, it occurs more frequently in the cell membrane complex (CMC), often involving the rupture of interlayer bonds. Therefore, a model of the CMC is presented, based on prior research in which we propose interconnecting bonds between the layers to assist in our interpretation of hair-fracturing mechanisms for cuticle chipping, deep transverse cuticle cracks, cracks during heat drying, scale lifting by surfactants, and catastrophic failure. Failure in the wet state generally involves hydrophilic layers, e.g., the contact zone of the CMC or the endocuticle or bonding to these hydrophilic layers, whereas failure in the dry state generally involves bonding between hydrophobic layers, e.g., beta-delta failure. Chemical damage by perms, bleaches, and sunlight, by breaking specific chemical bonds, influences the sites of initial failure and increases the number of routes for crack propagation, leading to more complex fracture patterns.