The effect of primary amino acid sequence in recombinant spidroins on their spatial organization is crucial for the fabrication of artificial fibers and fibrous materials. This study focuses on the rheological properties of aqueous and alcoholic solutions of recombinant analogs of natural spidroins (rS1/9 and rS2/12), as well as the structure of their films and nanofibrous materials. Non-Newtonian flow behavior of aqueous solutions of these proteins was observed at certain concentrations in contrast to their solutions in hexafluoroisopropanol.
View Article and Find Full Text PDFA clinical case of incorrect verification of the angiosarcoma of the ethmoidal labyrinth and frontal sinus in a 36-year-old man is presented. A feature of this case is the disregard of additional research methods without taking into account the unilateralism of the pathological process, which led to the wrong tactics of surgical treatment and the development of a relapse of the disease complicated by nasal liquorrhea. A thorough examination of the patient and an analysis of a series of computer tomograms of the paranasal sinuses suggested a diagnosis of malignancy.
View Article and Find Full Text PDFThe periodontal pathogen Tannerella forsythia utilizes host sialic acids as a nutrient source. To also make O-acetylated sialyl residues susceptible to the action of its sialidase and sialic acid uptake system, Tannerella produces NanS, an O-acetylesterase with two putative catalytic domains. Here, we analyzed NanS by homology modeling, predicted a catalytic serine-histidine-aspartate triad for each catalytic domain and performed individual domain inactivation by single alanine exchanges of the triad nucleophiles S32 and S311.
View Article and Find Full Text PDFStructural organization of hydrogen and oxygen functionalized nanodiamond (ND) particles in hydrosols was investigated using a cryo-TEM method. The formation of chain-like structures was observed for hydrogen functionalized NDs while oxygen functionalized NDs tend to form more compact structures. In order to understand possible interaction mechanisms between NDs in hydrosols and to explain these experimental results, first-principles calculations were performed.
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