Designing multifunctional CoOx layers for efficient and stable electrochemical energy conversion

Disordered and porous metal oxides are promising as earth-abundant and cost-effective alternatives to noble-metal electrocatalysts. Herein, we leverage non-saturated oxidation in plasma-enhanced atomic layer deposition to tune structural, mechanical, and optical properties of biphasic CoOx thin films, thereby tailoring their catalytic activities and chemical stabilities. To optimize the resulting film properties, we systematically vary the oxygen plasma power and exposure time in the deposition process. We find that short exposure times and low plasma powers incompletely oxidize the cobaltocene precursor to Co(OH)2 and result in the incorporation of carbon impurities. These Co(OH)2 films are highly porous and catalytically active, but their electrochemical stability is impacted by poor adhesion to the substrate. In contrast, long exposure times and high plasma powers completely oxidize the precursor to form Co3O4, reduce the carbon impurity incorporation, and improve the film crystallinity. While the resulting Co3O4 films are highly stable under electrochemical conditions, they are characterized by low oxygen evolution reaction activities. To overcome these competing properties, we applied the established relation between deposition parameters and functional film properties to design bilayer films exhibiting simultaneously improved electrochemical performance and chemical stability. The resulting biphasic films combine a highly active Co(OH)2 surface with a stable Co3O4 interface layer. In addition, these coatings exhibit minimal light absorption, thus rendering them well suited as protective catalytic layers on semiconductor light absorbers for application in photoelectrochemical devices.

Elevated Temperature and Exposure to Copper Leads to Changes in the Antioxidant Defense System of the Reef-Building Coral Mussismilia harttii

The frequency and severity of coral bleaching events have increased in recent years. Global warming and contamination are primarily responsible for triggering these responses in corals. Thus, the objective of this study was to evaluate the isolated and combined effects of elevated temperature and exposure to copper (Cu) on responses of the antioxidant defense system of coral Mussismilia harttii. In a marine mesocosm, fragments of the coral were exposed to three temperatures (25.0, 26.6, and 27.3°C) and three concentrations of Cu (2.9, 5.4, and 8.6 μg/L) for up to 12 days. Levels of reduced glutathione (GSH) and the activity of enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutamate cysteine ligase (GCL), were evaluated on the corals and symbionts. The short exposure to isolated and combined stressors caused a reduction in GSH levels and inhibition of the activity of antioxidant enzymes. After prolonged exposure, the combination of stressors continued to reduce GSH levels and SOD, CAT, and GCL activity in symbionts and GST activity in host corals. GCL activity was the parameter most affected by stressors, remaining inhibited after 12-days exposure. Interesting that long-term exposure to stressors stimulated antioxidant defense proteins in M. harttii, demonstrating a counteracting response that may beneficiate the oxidative state. These results, combined with other studies already published suggest that the antioxidant system should be further studied in order to understand the mechanisms of tolerance of South Atlantic reefs.

MODERN TECHNOLOGIES FOR THE MANUFACTURE OF GLASS-CERAMIC DENTAL PROSTHESES

The relevance of the problem of improving the quality of life and protecting human health in the context of the successful development of the modern society was presented. A literary review of well-known modern technologies for the design and manufacture of dental prostheses was carried out, as well as the leading domestic and foreign companies that were engaged in this were given. The history of the development of materials for obtaining clinical restorations (crowns, inlays, onlays, etc.) was considered and the main directions of the development of innovative ceramic materials for dental prosthetics were outlined. Based on the analysis of the properties of various types of materials for dental prosthetics, the prospects of using glass-ceramic materials in the development of dental prostheses have been substantiated. The chemical compositions of lithium silicate glasses for the synthesis of the glass matrix have been developed and the technological parameters for the production of glass-ceramic dental prostheses have been selected (Тgl. melting = 1350–1400 °С, Тheat treatment = 600–650 °С). Preliminary heat treatment before the formation of products ensures the formation of the required number of the nucleus of crystalline phase and the prerequisites for creating a volume crystallized structure under conditions of short-term heat treatment. The glass-ceramic prosthesis with a formed interpenetrating sitallized structure was obtained by the method of hot pressing with a short exposure (18-20 min). It was found that the obtained glass-ceramic material containing lithium disilicate as a crystalline phase in an amount of 40-60 vol. %, had high values of bending strength (σ = 400 MPa) and fracture toughness. The indicated mechanical properties of the developed materials, along with the approximate values of their modulus of elasticity to natural teeth, will significantly extend the service life of products under conditions of significant alternating loads that arise during the chewing cycle. A comparative assessment of the competitiveness of the developed dental prostheses based on lithium disilicate with world analogues was carried out, in particular the products of Ivoclar Vivadent and Vita Zahnfabrik, in terms of the main operational parameters. The positive effect of the introduction of domestic developed glass-ceramic dental prostheses to reduce import dependence has been determined.

Gingival Epithelial Cell-Derived Microvesicles Activate Mineralization in Gingival Fibroblasts

Soft tissue calcification occurs in many parts of the body, including the gingival tissue. Epithelial cell-derived MVs can control many functions in fibroblasts but their role in regulating mineralization has not been explored. We hypothesized that microvesicles (MVs) derived from gingival epithelial cells could regulate calcification of gingival fibroblast cultures in osteogenic environment. Human gingival fibroblasts (HGFs) were cultured in osteogenic differentiation medium with or without human gingival epithelial cell-derived MV stimulation. Mineralization of the cultures, localization of the MVs and mineral deposits in the HGF cultures were assessed. Gene expression changes associated with MV exposure were analyzed using gene expression profiling and real-time qPCR. Within a week of exposure, epithelial MVs stimulated robust mineralization of HGF cultures that was further enhanced by four weeks. The MVs taken up by the HGF's did not calcify themselves but induced intracellular accumulation of minerals. HGF gene expression profiling after short exposure to MVs demonstrated relative dominance of inflammation-related genes that showed increases in gene expression. In later cultures, OSX, BSP and MMPs were significantly upregulated by the MVs. These results suggest for the first time that epithelial cells maybe associated with the ectopic mineralization process often observed in the soft tissues.

Untargeted Metabolomics Reveals a Complex Impact on Different Metabolic Pathways in Scallop Mimachlamys varia (Linnaeus, 1758) after Short-Term Exposure to Copper at Environmental Dose

Ports are a good example of how coastal environments, gathering a set of diverse ecosystems, are subjected to pollution factors coming from human activities both on land and at sea. Among them, trace element as copper represents a major factor. Abundant in port ecosystem, copper is transported by runoff water and results from diverse port features (corrosion of structures, fuel, anti-fouling products, etc.). The variegated scallop Mimachlamys varia is common in the Atlantic port areas and is likely to be directly influenced by copper pollution, due to its sessile and filtering lifestyle. Thus, the aim of the present study is to investigate the disruption of the variegated scallop metabolism, under a short exposure (48 h) to a copper concentration frequently encountered in the waters of the largest marina in Europe (82 μg/L). For this, we chose a non-targeted metabolomic approach using ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS), offering a high level of sensitivity and allowing the study without a priori of the entire metabolome. We described 28 metabolites clearly modulated by copper. They reflected the action of copper on several biological functions such as osmoregulation, oxidative stress, reproduction and energy metabolism.

Fast Improvement of TEM Images with Low-Dose Electrons by Deep Learning

Low electron dose observation is indispensable for observing various samples using a transmission electron microscope; consequently, image processing has been used to improve transmission electron microscopy (TEM) images. To apply such image processing to in situ observations, we here apply a convolutional neural network to TEM imaging. Using a dataset that includes short-exposure images and long-exposure images, we develop a pipeline for processed short-exposure images, based on end-to-end training. The quality of images acquired with a total dose of approximately $5$ $e^{-}$ per pixel becomes comparable to that of images acquired with a total dose of approximately $1{,}000$ $e^{-}$ per pixel. Because the conversion time is approximately 8 ms, in situ observation at 125 fps is possible. This imaging technique enables in situ observation of electron-beam-sensitive specimens.

Low-Temperature Plasma Short-Exposure to Decontaminate Peri-Implantitis-Related Multispecies Biofilms on Titanium Surfaces

Peri-implantitis is a bacteria-initiated infection that as yet has no effective treatment. A novel approach to treat peri-implantitis is the use of low-temperature plasma (LTP). LTP disrupts the biofilm while conditioning the surrounding host environment for bone growth around the infected implant. The goal of this study was to evaluate the antimicrobial properties of LTP on newly formed (24-h) and mature (7-days) peri-implant-related biofilms. Biofilm was composed of Actinomyces naeslundii (ATCC 12104), Porphyromonas gingivalis (W83), Streptococcus oralis (ATCC 35037), and Veillonella dispar (ATCC 17748). They were cultivated in brain heart infusion supplemented with 1% yeast extract, hemin (0.5 mg/mL), and menadione (5 mg/mL) and kept at 37⁰C in anaerobic conditions for 24-h. The species were mixed for a final concentration of ~105 colony forming units (CFU)/mL (OD=0.01), and the bacterial suspension was transferred to 24-well plates containing titanium specimens. Biofilms were treated with LTP for 1, 3, and 5 min at 3 or 10 mm from plasma-tip to sample. Controls were no treatment (Negative control=NC) and argon-flow at the same LTP conditions. Positive controls were 14 g/mL amoxicillin and 140 µg/mL metronidazole individually or combined, and 0.12% chlorhexidine. Biofilms were evaluated by CFU, confocal laser scanning microscopy (CLSM), and Fluorescence in situ Hybridization (FISH). Wilcoxon Signed-Rank and Wilcoxon Rank Sum tests were applied (α = 0.05). Bacterial growth was observed in all no-treatment groups corroborated by FISH. LTP treatment significantly reduced all bacteria species when compared to the NC in both tested periods and in all treatment combinations (p≤0.016), these results were corroborated by CLSM. There were no significant differences during biofilm development, between 24-h, 3, and 7 days within each LTP treatment, or among the bacteria within each LTP treatment (p≥0.05). LTP application is effective to reduce peri-implantitis-related multispecies biofilms on titanium surfaces.

Functional Significance of Selective Expression of ERα and ERβ in Mammary Gland Organ Culture

Thoracic pair of mammary glands from steroid hormone-pretreated mice respond to hormones structurally and functionally in organ culture. A short exposure of glands for 24 h to 7,12 Dimethylbenz(a)anthracene (DMBA) during a 24-day culture period induced alveolar or ductal lesions. Methods: To differentiate the functional significance of ERα and ERβ, we employed estrogen receptor (ER) knockout mice. We compared the effects of DMBA on the development of preneoplastic lesions in the glands in the absence of ERα (αERKO) and ERβ (βERKO) using an MMOC protocol. Glands were also subjected to microarray analyses. We showed that estradiol can be replaced by EGF for pretreatment of mice. The carcinogen-induced lesions developed under both steroids and EGF pretreatment protocols. The glands from αERKO did not develop any lesions, whereas in βERKO mice in which ERα is intact, mammary alveolar lesions developed. Comparison of microarrays of control, αERKO and βERKO mice showed that ERα was largely responsible for proliferation and the MAP kinase pathways, whereas ERβ regulated steroid metabolism-related genes. The results indicate that ERα is essential for the development of precancerous lesions. Both subtypes, ERα and Erβ, differentially regulated gene expression in mammary glands in organ cultures.

162 Whole-body cryotherapy treatment modulates the innate immune response in non-professional football players

Aims Whole-body cryotherapy (WBC) is a recently widely strategy used for muscle recovery after injury that can to activate inflammatory response. WBC consists of short exposure, of about 2-3 minutes, to dry air at cryogenic temperatures up to -190 °C. The aim of our study is to analyze WBC effects on metabolic, hormonal, and immunological responses of non-professional football players (NPFPs). Methods and results Nine male NPFPs (age: 20 ± 2 years) on the same team are recruited and, in particular, they played and trained each day before, during, and after WBC treatment. We collected NPFPs blood samples immediately before WBC and after 5 once-day sessions, then we evaluated a set consisting of 50 analytes, including hormones profile, haematologic parameters, and serum chemistry. We proceeded with monocytes (Mo) phenotyping and then we investigated the concentration of some plasmatic markers with anti-inflammatory effects (IL2RA, IL1RN) or typically increased during inflammation [CCL2, IL-18, free mitochondrial DNA (mtDNA)]. WBC treatment (WBC-t) lead to a decrease not only in mean platelet volume, mean corpuscular haemoglobin, and ferritin levels, but also in testosterone and estradiol levels, even if they remain within the normal ranges. This treatment is also responsible for total Mo increased and, in particular, a reduction of classical Mo has been demonstrated in parallel with an increase of non-classical ones. Moreover, each Mo subset shows lower expression of CXCR4. Considering pro-inflammatory molecules, IL1RA showed a tendency to decrease, while IL1RN and IL18 decreased in plasma after WBC-t. Conversely, circulating mtDNA levels appeared unaltered by treatment. Conclusions The differences detected in monocyte subset after WBC-t suggest that, in this condition, Mo could be redistributed into the surrounding tissue. In addition, CXCR4 reduction in Mo subsets could be due to their differentiation process. Hence, WBC could promote Mo differentiation through a mechanism that is still unknown. Since WBC seems to regulate the innate immune system in the enrolled NPFPs, it could have a role in tissue repair beyond a beneficial anti-inflammatory effect.