6 citations,
February 2021 in “Proteins” Researchers found that the most reachable bonds in wool fibers are near the ends of certain proteins, which help stabilize the fiber's structure.
December 2011 in “The Egyptian Journal of Histology” High-fructose diets can cause irreversible kidney damage.
48 citations,
May 2019 in “Genome Biology” Researchers found that certain RNA circles in the brain are linked to disease risk, but their exact role in disease is still unknown.
November 2022 in “International journal of trichology” Glyoxylic acid straighteners cause more protein loss but have similar hair strength effects as traditional alkaline straighteners.
27 citations,
February 1991 Cuticle damage doesn't affect hair's tensile strength; the cortex is responsible for it.
19 citations,
May 2008 in “Applied spectroscopy” Human hair has different protein structures in its cuticle and cortex.
19 citations,
July 1964 in “PubMed” Hair follicle cells become four types: medulla, cortex, cuticle, and inner root sheath.
5 citations,
December 2020 in “International journal of biological macromolecules” Treatments improved hair surface and scale structure but didn't increase certain bonds in the hair cortex.
1 citations,
January 2007 in “AIP conference proceedings” High-resolution x-ray images showed three main structures in human hair: medulla, cortex, and cuticle.
1 citations,
January 2003 in “Dermatology” Finasteride's effectiveness measured by observing hair cortex changes using a cheap and easy method.
62 citations,
December 2008 in “Journal of structural biology” Hair curvature in Japanese people is linked to specific cell types and filament arrangements in the hair cortex.
67 citations,
December 2009 in “Stem Cells” β-Catenin signaling is involved in brain cell growth after injury and could be a therapy target.
52 citations,
February 2005 in “Biopolymers” Chemical hair straightening changes hair proteins and mostly fixes broken bonds.
42 citations,
January 2011 in “Journal of Biomedical Optics” Infrared and Raman imaging can non-destructively analyze hair structure and help diagnose hair conditions.
31 citations,
December 2002 in “Biochimica et biophysica acta. G, General subjects/Biochimica et biophysica acta. General subjects (Online)” The research found two types of calcium in human hair, one that varies among individuals and another that is consistent across people.
30 citations,
September 2018 in “International Journal of Cosmetic Science” Bleaching hair causes severe structural and chemical damage, including protein loss and oxidation.
27 citations,
January 1995 Melanin in black hair protects it from sun damage better than light-brown hair.
20 citations,
December 2012 in “Journal of molecular structure” The study found that thioglycolic acid breaks down hair bonds more consistently than l-cysteine, which is less damaging to hair.
18 citations,
August 2014 in “Lipids” Human hair has more unsaturated fats inside than on the surface, and certain lipids may help bind the outer and inner layers together.
18 citations,
November 2010 in “Journal of morphology” Antler velvet hair and body hair of red deer have different structures that help with protection and insulation.
18 citations,
January 1994 in “Skin pharmacology and physiology” Sunlight damages hair, causing cuticle loss, protein changes, and discoloration.
17 citations,
June 2012 in “Journal of experimental zoology. Part B, Molecular and developmental evolution” Hair in mammals likely evolved from glandular structures, not scales.
15 citations,
May 2010 in “International Journal of Cosmetic Science” The cell membrane complex in mammalian hair has three distinct types with different structures and chemical properties.
15 citations,
February 1999 in “The anatomical record” Some mutant mice have hair with abnormal cross-linking, mainly in the cuticle, not affecting other hair parts.
14 citations,
December 2016 in “PloS one” Keratin 26 affects cashmere goat hair growth and is influenced by various treatments.
13 citations,
March 2019 in “Journal of cosmetic dermatology” Heat damages hair, with Asian hair losing more protein than Caucasian hair.
11 citations,
January 2000 in “Journal of cosmetic science” Hydrolyzed wheat proteins penetrate all hair types effectively.
10 citations,
January 2012 in “Journal of biomedical optics” Melanin density affects hair color, and this method can help in cosmetic assessments and diagnosing hair diseases.
10 citations,
January 2002 in “Nihon Keshouhin Gijutsushakaishi/Journal of S C C./Nihon Keshouhin Gijutsushakai kaishi” The cuticle significantly contributes to hair stiffness, making up about 60% of the total bending stress.
10 citations,
October 2001 in “PubMed” The conclusion is that substances can penetrate hair fibers through multiple pathways, including both the cell membrane complex and the non-keratinous parts.