This study presents an in vitro experimental method to determine shear properties of the epidermis. Shear tests were performed with a parallel plate rheometer on samples of stratum corneum and the viable epidermis. The method was validated on very thin silicon sheets. Preliminary test were performed to determine the linear viscoelastic range, the effect of normal loading on the sample and the time to reach equilibrium after changes of temperature and relative humidity. The study shows that reproducible results can be obtained for the shear properties of epidermis in an in vitro set up. The dynamic shear modulus for stratum corneum ranges from about 4-12 kPa, decreasing with increasing relative humidity. The values are considerably lower than the shear modulus value based on tensile Young's moduli in the literature, indicating a considerable anisotropic material behavior. Results for the epidermis were of the same order of magnitude, but were less consistent possibly due to a less well-defined tissue composition.
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http://dx.doi.org/10.3233/BIR-2011-0590 | DOI Listing |
Soft Matter
January 2025
Division of Physical Chemistry, Department of Chemistry, Lund University, PO Box 124, SE-221 00 Lund, Sweden.
Attempts to use colloid science concepts to better understand the dynamic properties of concentrated or crowded protein solutions are challenging due to the fact that globular proteins generally have heterogeneous surfaces that result in anisotropic or patchy contributions to their interaction potential. This is particularly difficult when targeting non-equilibrium transitions such as glass and gel formation in concentrated protein solutions. Here we report a systematic study of the reduced zero shear viscosity of the globular protein -crystallin, an eye lens protein that plays a vital role in vision-related phenomena such as cataract formation or presbyopia, and compare the results to the existing structural and dynamic data.
View Article and Find Full Text PDFScience
January 2025
Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
Architected materials derive their properties from the geometric arrangement of their internal structural elements. Their designs rely on continuous networks of members to control the global mechanical behavior of the bulk. In this study, we introduce a class of materials that consist of discrete concatenated rings or cage particles interlocked in three-dimensional networks, forming polycatenated architected materials (PAMs).
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Technical University of Munich (TUM), TUM School of Life Sciences Weihenstephan, Alte Akademie 8, 85354 Freising, Germany; Fraunhofer Institute for Process Engineering and Packaging IVV, Giggenhauser Str. 35, 85354 Freising, Germany. Electronic address:
Macauba fruit pulp (Acrocomia aculeata) is an emerging oil source. After de-oiling, the macauba pulp meal (MPM) offers a dietary fiber content of 40-50 %, which mainly comprises cell wall polysaccharides (CWP). The present work aimed to assess the potential of MPM as an innovative source of sustainable food polysaccharides.
View Article and Find Full Text PDFJ Food Sci
January 2025
College of Food Science and Engineering, Henan University of Technology, Zhengzhou, China.
Flaxseed gum (FSG) has promising applications in the field of nano/microencapsulation for its biocompatibility and excellent physicochemical properties. In this study, FSG-based nano-microcapsules (FSG NPs) were prepared using high-speed shear homogenization combined with ultrasound for efficient encapsulation of secoisolariciresinol diglucoside (SDG). The particle size of FSG stands for nano-microcapsules (NP) was determined to be 336.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Civil Engineering , University of Engineering and Technology Peshawar, Peshawar, Pakistan.
For millennia mud has been utilized to make brick for the construction of both residential as well as architectural purposes. However, concerns regarding their vulnerability to different kinds of hazards due to their weak mechanical properties and durability have emerged. This study addressed the global challenge of developing sustainable and affordable construction materials, particularly in resource-constrained regions.
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