Dually Reactive Multilayer Coatings Enable Orthogonal Manipulation of Underwater Superoleophobicity and Oil Adhesion via Post-Functionalization

Fish scale-inspired underwater superoleophobic coatings with low oil adhesion can be achieved through the creation of hierarchical surface topography on water-compatible materials (including polymeric hydrogels, metal oxides, and electrostatic multilayers)....

Late Medieval complexes of the forest-steppe and sub-taiga Trans-Urals (based on materials from the settlement of Stary Pogost)

The paper concerns the results of the archaeological investigation of the Late Medieval sites in the forest-steppe and sub-taiga regions of Trans-Urals (Western Siberia). With the example of the fortress of Stary Pogost, and using the materials on all studied Late Medieval sites of the region (the hillforts of Yelyak-Alyp, Maloye Bakalskoye, Chingi-Tura, Isker, Kuchum-gora, Ivanovskoye, Dolgovskoye 1, the sanctuary of Tsingalinskoye), the main aspects of the material culture of the population of the 14th–16th centuries have been reconstructed. The building structures are represented by above-ground or slightly sunken permanent buildings with pise-walled hearths. In the cultural level, ashy spots, cumulations of fish-scale, and bones of fish and animals were recorded. The sea-sonal occupancy of most of the settlements, thin cultural layer, small quantity or complete absence of ceramics complicate distinguishing of the Late-Medieval complexes from the full array of Medieval monuments of the forest-steppe and sub-taiga Trans-Urals. A statistical analysis of the ceramics collections from all Late Medieval sites of the Trans-Urals was carried out. Four main types of the ware were identified. By correlation with contemporaneous collections of the Middle Irtysh, local specifics of the ceramics of the studied region were determined. The small amount of the stoneware was noted. The decline of the ceramics manufacture reflected in the composition of the clay dough, surface finish, and shape of the vessels, and it was manifested by poor ornamentation or complete absence of décor. One type of the ware – large cauldron-shaped vessels with thick vertical or slightly inside-bent walls, flattened bottom, and poor ornamentation – was recorded only in the territory of the forest-steppe and sub-taiga Trans-Urals, as well as in the Ishym River area. This indicates its earlier chronological position (13th–14th cc. A.D.) and association with the population of the emerging Siberian Tatars. A widespread became the ware made from organic materials – wood and bark, as well as imported ware, including metallic items.

Effect Collagen Concentration Tilapia Scales on the Quality of Burn Ointment

Collagen is one of the main connective tissue animal proteins and has been widely used as a biomedical material. Collagen is divided into XIX types. Type I collagen, among others, is obtained from bone, scales and skin. Collagen derived from type I can repair tissue or accelerate tissue regeneration to heal burns. The purpose of this research was to determine the addition of fish scale collagen extract to the characteristics of the burn ointment preparation in accordance with the Indonesian National Standard (SNI) and the best quality. The method used in this research is an experimental method of Completely Randomized Design (CRD) consisting of 4 collagen addition treatments: 0%, 2%, 4% and 6% repeated 5 times. Parameters in this method include physical-chemical parameters (pH, spreadability, shelf life and homogeneity) and organoleptic parameters (appearance, aroma, texture and color). Bayes test results, the concentration of the addition of tilapia scale collagen in the ointment preparation of 4% resulted in a value close to the control treatment. The addition of 4% collagen was the best treatment compared to 2% and 6% with a pH value of 6.12, dispersion of 3.22 cm, safe ointment preparation did not change at all during 28 days of storage. Based on the results of the organoleptic test parameters, the ointment at this concentration had a homogeneous appearance, slightly yellowish white color, a distinctive smell of collagen and a semi-solid texture, this was in accordance with the quality standard of the ointment and had the best quality characteristics.

Extraction of Chitosan From Fish Scale for Food Preservation and Shelf-Life Enhancer

With the growing demand for chitosan in a variety of applications and the drawbacks associated with crustacean shell-based chitosan, there is a need to look for alternative sources of chitosan extraction and production. Chitosan was extracted from the scales of red snapper ( Lutjanus johnii ) in this study. It was discovered that the concentration of solvent (HCl and NaOH) and temperature at various stages of the extraction process influenced the yield of extracted fish scale chitosan. The characterization result revealed that the commercial crustacean-based chitosan and the extracted fish scale chitosan had similar Fourier-transform infrared spectroscopy (FTIR) spectra, indicating that the two had similar functional groups. The degree of deacetylation (DDA) of the extracted fish scale chitosan was determined to be 76.9%, with the ash value, loss on drying, and solubility being 1.28%, 3.62%, and 88.8%, respectively. The extracted and commercialised chitosan were found to be similar in all characterization results. The potential of fish scale chitosan as a food preservative and shelf-life enhancer was then investigated in this study. Strawberries coated with chitosan were stored at various temperatures, and their physical appearance and moisture loss were recorded. When used in conjunction with traditional preservation techniques such as storage in a cool environment, fish scale chitosan was found to be capable of preventing up to 50% moisture loss in strawberries.

Low-temperature synthesis of oxygen-rich fish-scale-like porous boron nitride for effective water cleaning

Effective removal of the organic pollutants from aqueous solution is significative and challenging for environmental sustainability. The high-performance adsorbent materials need to be developed. In this study, oxygen-rich fish-scale-like porous boron nitride (O-PBN) was facilely synthesized only at 900[Formula: see text]C (about 400[Formula: see text]C lower than that of the conventional process) through the molten salt method. The adsorption capacity of the as-prepared O-PBN for Methylene Blue (MB) from water was 422.6 mg/g, resulting from oxidizing groups and B–O bonds induced by oxygen doping as well as fish-scale-like structure composed of the BN nanoflakes. Moreover, the initial removal capacity of O-PBN only lost 7.6% even after 10 adsorption–regeneration cycles due to their strong resistance to oxidation. The unique B–O polar covalent bond, fish-scale-like two-dimensional nanostructure exposing the active adsorption sites to the surface ((002) crystal plane) and high specific surface area of O-PBN are confirmed to be the key factors in significantly enhancing water purification and regeneration performance. Overall, the synthetic method should help to a low-temperature and facile fabrication of O-PBN for effective water cleaning.

Maturation process and characterization of a novel thermostable and halotolerant subtilisin-like protease with high collagenolytic but low gelatinolytic activity

Enzymatic degradation of collagen is of great industrial and environmental significance; however, little is known about thermophile-derived collagenolytic proteases. Here, we report a novel collagenolytic protease (TSS) from thermophilic Brevibacillus sp. WF146. The TSS precursor comprises a signal peptide, an N-terminal propeptide, a subtilisin-like catalytic domain, a β-jelly roll (βJR) domain, and a prepeptidase C-terminal (PPC) domain. The maturation of TSS involves a stepwise autoprocessing of the N-terminal propeptide and the PPC domain, and the βJR rather than the PPC domain is necessary for correct folding of the enzyme. Purified mature TSS displayed optimal activity at 70°C and pH 9.0, a half-life of 1.5 h at 75°C, and an increased thermostability with rising salinity up to 4 M. TSS possesses an increased number of surface acidic residues and ion pairs, as well as four Ca 2+ -binding sites, which contribute to its high thermostability and halotolerance. At high temperatures, TSS exhibited high activity toward insoluble type I collagen and azocoll, but showed a low gelatinolytic activity, with a strong preference for Arg and Gly at the P1 and P1’ positions, respectively. Both the βJR and PPC domains could bind but not swell collagen, and thus facilitate TSS-mediated collagenolysis via improving the accessibility of the enzyme to the substrate. Additionally, TSS has the ability to efficiently degrade fish scale collagen at high temperatures. IMPORTANCE Proteolytic degradation of collagen at high temperatures has the advantages of increasing degradation efficiency and minimizing the risk of microbial contamination. Reports on thermostable collagenolytic proteases are limited, and their maturation and catalytic mechanisms remain to be elucidated. Our results demonstrate that the thermophile-derived TSS matures in an autocatalytic manner, and represents one of the most thermostable collagenolytic proteases reported so far. At elevated temperatures, TSS prefers hydrolyzing insoluble heat-denatured collagen rather than gelatin, providing new insight into the mechanism of collagen degradation by thermostable collagenolytic proteases. Moreover, TSS has the potential to be used in recycling collagen-rich wastes such as fish scales.