The structural evolution of regenerated Bombyx mori silk fibroin during shearing with a Couette cell has been studied in situ by synchrotron radiation small- and wide-angle x-ray scattering techniques. An elongation of fibroin molecules was observed with increasing shear rate, followed by an aggregation phase. The aggregates were found to be amorphous with beta-conformation according to infrared spectroscopy. Scanning x-ray microdiffraction with a 5 microm beam on aggregated material, which had solidified in air, showed silk II reflections and a material with equatorial reflections close to the silk I structure reflections, but with strong differences in reflection intensities. This silk I type material shows up to two low-angle peaks suggesting the presence of water molecules that might be intercalated between hydrogen-bonded sheets.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/bip.20083 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Resolving electrochemically triggered topological defect dynamics and structural degradation in layered oxides.
Proc Natl Acad Sci U S A
January 2025
Department of Physics and Astronomy, University of California, Irvine, CA 92697.
Understanding topological defects-controlled structural degradation of layered oxides-a key cathode material for high-performance lithium-ion batteries-plays a critical role in developing next-generation cathode materials. Here, by constructing a nanobattery in an electron microscope enabling atomic-scale monitoring of electrochemcial reactions, we captured the electrochemically driven atomistic dynamics and evolution of dislocations-a most important topological defect in material. We deciphered how dislocations nucleate, move, and annihilate within layered cathodes at the atomic scale.
View Article and Find Full Text PDFDiversification and recurrent adaptation of the synaptonemal complex in Drosophila.
PLoS Genet
January 2025
Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada.
The synaptonemal complex (SC) is a protein-rich structure essential for meiotic recombination and faithful chromosome segregation. Acting like a zipper to paired homologous chromosomes during early prophase I, the complex is a symmetrical structure where central elements are connected on two sides by the transverse filaments to the chromatin-anchoring lateral elements. Despite being found in most major eukaryotic taxa implying a deeply conserved evolutionary origin, several components of the complex exhibit unusually high rates of sequence turnover.
View Article and Find Full Text PDFAmbivalent partnership of the Drosophila posterior class Hox protein Abdominal-B with Extradenticle and Homothorax.
PLoS Genet
January 2025
Centro de Biología Molecular Severo Ochoa (CBM), CSIC-UAM, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
Hox proteins, a sub-group of the homeodomain (HD) transcription factor family, provide positional information for axial patterning in development and evolution. Hox protein functional specificity is reached, at least in part, through interactions with Pbc (Extradenticle (Exd) in Drosophila) and Meis/Prep (Homothorax (Hth) in Drosophila) proteins. Most of our current knowledge of Hox protein specificity stems from the study of anterior and central Hox proteins, identifying the molecular and structural bases for Hox/Pbc/Meis-Prep cooperative action.
View Article and Find Full Text PDFIdentification of novel genes responsible for a pollen killer present in local natural populations of Arabidopsis thaliana.
PLoS Genet
January 2025
Université Paris-Saclay, INRAE, AgroParisTech, Institute Jean-Pierre Bourgin for Plant Sciences (IJPB), Versailles, France.
Gamete killers are genetic loci that distort segregation in the progeny of hybrids because the killer allele promotes the elimination of the gametes that carry the sensitive allele. They are widely distributed in eukaryotes and are important for understanding genome evolution and speciation. We had previously identified a pollen killer in hybrids between two distant natural accessions of Arabidopsis thaliana.
View Article and Find Full Text PDFBoosting the Hydrogen Evolution Activity of a Low-Coordinated Co─N─C Catalyst via Vacancy Defect-Mediated Alteration of the Intermediate Adsorption Configuration.
Adv Sci (Weinh)
January 2025
State Key Laboratory for Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education and College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.
The cobalt-nitrogen-carbon (Co─N─C) single-atom catalysts (SACs) are promising alternatives to precious metals for catalyzing the hydrogen evolution reaction (HER) and their activity is highly dependent on the coordination environments of the metal centers. Herein, a NaHCO etching strategy is developed to introduce abundant in-plane pores within the carbon substrates that further enable the construction of low-coordinated and asymmetric Co─N sites with nearby vacancy defects in a Co─N─C catalyst. This catalyst exhibits a high HER activity with an overpotential (η) of merely 78 mV to deliver a current density of 10 mA cm, a Tafel slope of 45.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!