Ultrasound-Based Quantification of Cartilage Damage After In Vivo Articulation With Metal Implants

Objective This study aims to evaluate the applicability of the ultrasound roughness index (URI) for quantitative assessment of cartilage quality ex vivo (post-mortem), after 6 months of in vivo articulation with a Focal Knee Resurfacing Implant (FKRI). Design Goats received a metal FKRI ( n = 8) or sham surgery ( n = 8) in the medial femoral condyles. After 6 months animals were sacrificed, tibial plateaus were stained with Indian ink, and macroscopic scoring of the plateaus was performed based on the ink staining. The URI was calculated from high-frequency ultrasound images at several sections, covering both areas that articulated with the implant and non-articulating areas. Cartilage quality at the most damaged medial location was evaluated with a Modified Mankin Score (MMS). Results The URI was significantly higher in the FKRI-articulating than in the sham plateaus at medial articulating sections, but not at sections that were not in direct contact with the implant, for example, under the meniscus. The mean macroscopic score and MMS were significantly higher in the FKRI-articulating group than in the sham group ([Formula: see text], [Formula: see text], respectively). Correlation coefficients between URI and macroscopic score were significant in medial areas that articulated with the implant. A significant correlation between URI and MMS was found at the most damaged medial location ([Formula: see text]). Conclusions This study demonstrates the potential of URI to evaluate cartilage roughness and altered surface morphology after in vivo articulation with a metal FKRI, rendering it a promising future tool for quantitative follow-up assessment of cartilage quality.

Effect of Al2O3 Sandblasting Particle Size on the Surface Topography and Residual Compressive Stresses of Three Different Dental Zirconia Grades

This study investigated the effect of sandblasting particle size on the surface topography and compressive stresses of conventional zirconia (3 mol% yttria-stabilized tetragonal zirconia polycrystal; 3Y-TZP) and two highly translucent zirconia (4 or 5 mol% partially stabilized zirconia; 4Y-PSZ or 5Y-PSZ). Plate-shaped zirconia specimens (14.0 × 14.0 × 1.0 mm3, n = 60 for each grade) were sandblasted using different Al2O3 sizes (25, 50, 90, 110, and 125 μm) under 0.2 MPa for 10 s/cm2 at a 10 mm distance and a 90° angle. The surface topography was characterized using a 3-D confocal laser microscopy and inspected with a scanning electron microscope. To assess residual stresses, the tetragonal peak shift at 147 cm−1 was traced using micro-Raman spectroscopy. Al2O3 sandblasting altered surface topographies (p < 0.05), although highly translucent zirconia showed more pronounced changes compared to conventional zirconia. 5Y-PSZ abraded with 110 μm sand showed the highest Sa value (0.76 ± 0.12 μm). Larger particle induced more compressive stresses for 3Y-TZP (p < 0.05), while only 25 μm sand induced residual stresses for 5Y-PSZ. Al2O3 sandblasting with 110 μm sand for 3Y-TZP, 90 μm sand for 4Y-PSZ, and 25 μm sand for 5Y-PSZ were considered as the recommended blasting conditions.

Understanding Differences Between Lakes and Reservoirs

There are many examples of how human activities alter species’ habitats, including the damming of lakes or rivers to create reservoirs. We build dams to create reservoirs that provide water and generate electricity for human needs. Scientists have learned that building new dams and creating reservoirs on lakes and rivers changes the local habitat, making it unsuitable for many species that once lived there. Through processes known as environmental flows, reservoirs can be operated to resemble natural lakes. However, we have not kept good records of where we built reservoirs, so scientists have devised creative ways to map where these and associated dams occur across the globe. When we know where reservoirs and dams occur, we are better prepared to determine how these have altered surface water on the planet and impacted animals, plants, and humans.

WATER MONITORING IN UKRAINE: METHODS FOR ASSESSING WATER QUALITY FOR VARIOUS PURPOSES IN CONNECTION WITH CHANGES IN THE REGULATORY FRAMEWORK (2014-2021)

Over the past five years (2014-2021), there have been significant changes in regulatory methods for assessing water quality for various purposes, which is due to Ukraine’s course towards European integration. An important feature was the cancellation of the acts of sanitary legislation of the Ukrainian SSR and the USSR (from 01.01.2017), which were applied in Ukraine for a long time (order of the Cabinet of Ministers of Ukraine of 2016). The Law of Ukraine “On Amendments to Certain Legislative Acts of Ukraine Concerning the Implementation of Integrated Approaches in Water Resources Management Based on the Basin Principle” (2016) amended the Water Code of Ukraine regarding hydrographic zoning and water monitoring in accordance with the provisions of the EU Water Framework Directive. In 2018, by a resolution of the Cabinet of Ministers of Ukraine, the “Procedure for the implementation of state monitoring of waters” was approved. In 2019, the Ministry of Natural Resources of Ukraine approved the normative “Methodology for assigning a surface water array to one of the classes of the ecological and chemical states of a surface water array, as well as assigning an artificial or significantly altered surface water array to one of the classes of the ecological potential of an artificial or significantly altered surface water array” The objects of state monitoring of waters are land and ground water bodies and sea waters. Surface water body – a specially defined surface water body or part of it. The body of surface waters can be classified into one of five categories: 1) rivers; 2) lakes; 3) transitional waters; 4) coastal waters; 5) artificial or substantially altered surface water bodies. The program of state monitoring of waters provides for control over four groups of indicators: 1) biological; 2) physical and chemical; 3) chemical; 4) hydromorphological. Based on the data and information obtained as a result of the state monitoring of the waters of surface and groundwater bodies, the ecological and chemical state of the surface water bodies, the ecological potential of artificial or significantly altered surface water bodies, the quantitative and chemical state of the groundwater bodies are determined, taking into account which river basin management plans and assess the level of achievement of environmental objectives. The purpose of this study is to highlight the approaches that have developed at the present stage to the regulation of water quality for various purposes, the main of which are: environmental; hygienic (household and drinking and cultural and household or recreational water use), fishery. If, when assessing the quality of water for environmental purposes, a deviation from the maximum permissible concentrations (MPC) was made, then in other areas of water use, the MPC standards remain relevant. The importance of this study also lies in the need to convey generalized information to a wide range of authors who are interested in water quality issues.

Convergent evolution of diverse Bacillus anthracis outbreak strains toward altered surface oligosaccharides that modulate anthrax pathogenesis

Bacillus anthracis, a spore-forming gram-positive bacterium, causes anthrax. The external surface of the exosporium is coated with glycosylated proteins. The sugar additions are capped with the unique monosaccharide anthrose. The West African Group (WAG) B. anthracis have mutations rendering them anthrose deficient. Through genome sequencing, we identified 2 different large chromosomal deletions within the anthrose biosynthetic operon of B. anthracis strains from Chile and Poland. In silico analysis identified an anthrose-deficient strain in the anthrax outbreak among European heroin users. Anthrose-deficient strains are no longer restricted to West Africa so the role of anthrose in physiology and pathogenesis was investigated in B. anthracis Sterne. Loss of anthrose delayed spore germination and enhanced sporulation. Spores without anthrose were phagocytized at higher rates than spores with anthrose, indicating that anthrose may serve an antiphagocytic function on the spore surface. The anthrose mutant had half the LD50 and decreased time to death (TTD) of wild type and complement B. anthracis Sterne in the A/J mouse model. Following infection, anthrose mutant bacteria were more abundant in the spleen, indicating enhanced dissemination of Sterne anthrose mutant. At low sample sizes in the A/J mouse model, the mortality of ΔantC-infected mice challenged by intranasal or subcutaneous routes was 20% greater than wild type. Competitive index (CI) studies indicated that spores without anthrose disseminated to organs more extensively than a complemented mutant. Death process modeling using mouse mortality dynamics suggested that larger sample sizes would lead to significantly higher deaths in anthrose-negative infected animals. The model was tested by infecting Galleria mellonella with spores and confirmed the anthrose mutant was significantly more lethal. Vaccination studies in the A/J mouse model showed that the human vaccine protected against high-dose challenges of the nonencapsulated Sterne-based anthrose mutant. This work begins to identify the physiologic and pathogenic consequences of convergent anthrose mutations in B. anthracis.

Molecular Modeling of Pathogenic Mutations in the Keratin 1B Domain

Keratin intermediate filaments constitute the primary cytoskeletal component of epithelial cells. Numerous human disease phenotypes related to keratin mutation remain mechanistically elusive. Our recent crystal structures of the helix 1B heterotetramer from keratin 1/10 enabled further investigation of the effect of pathologic 1B domain mutations on keratin structure. We used our highest resolution keratin 1B structure as a template for homology-modeling the 1B heterotetramers of keratin 5/14 (associated with blistering skin disorders), keratin 8/18 (associated with liver disease), and keratin 74/28 (associated with hair disorder). Each structure was examined for the molecular alterations caused by incorporating pathogenic 1B keratin mutations. Structural modeling indicated keratin 1B mutations can harm the heterodimer interface (R265PK5, L311RK5, R211PK14, I150VK18), the tetramer interface (F231LK1, F274SK74), or higher-order interactions needed for mature filament formation (S233LK1, L311RK5, Q169EK8, H128LK18). The biochemical changes included altered hydrophobic and electrostatic interactions, and altered surface charge, hydrophobicity or contour. Together, these findings advance the genotype-structurotype-phenotype correlation for keratin-based human diseases.

Nanostructured Polystyrene Doped with Acetylsalicylic Acid and Its Antibacterial Properties

Homogeneous polystyrene foils doped with different concentrations of acetylsalicylic acid were prepared by the solvent casting method. The surface morphology and surface chemistry of as-prepared foils were characterized in detail. Excimer laser (krypton fluoride, a wavelength of 248 nm) was used for surface nanopatterning of doped polystyrene foils. Certain combinations of laser fluence and number of laser pulses led to formation of laser-induced periodic surface structures (LIPSS) on the exposed surface. Formation of the pattern was affected by the presence of a dopant in the polystyrene structure. Significant differences in surface chemistry and morphology of laser-treated foils compared to both pristine and doped polystyrene were detected. The pattern width and height were both affected by selection of input excimer exposure conditions, and the amount of 6000 pulses was determined as optimal. The possibility of nanostructuring of a honeycomb-like pattern doped with acetylsalicylic acid was also demonstrated. Selected nanostructured surfaces were used for study the antibacterial properties for a model bacteria strain of S. aureus. The combination of altered surface chemistry and morphology of polystyrene was confirmed to have an excellent antibacterial properties.

Roles of cytochromes c and b5 in mitochondria and microsomes: Classical and murburn perspectives

While cytochrome c (Cyt. c) is a soluble protein involved in mitochondrial electron transfer (ET) reactions between Complex III and Complex IV, cytochrome b5 (Cyt. b5) is a microsomal membrane protein acting as a redox aide for diverse cytochrome P450s and their unique reductase. We found little conservation in the sequence and surface amino acid residues of Cyt. c and b5 proteins among evolutionarily diverse species. Hence, the logic that these proteins mediate ET through affinity binding via specific surface residues is weak. Also, analysis of putative protein-protein interactions in the crystal structures of these proteins and their redox partners did not point to any specific interaction logic. The literature on kinetic and thermodynamic constants of mutants (with altered surface residues) did not provide strong evidence to support the binding-based ET paradigm. Topographically divergent Cyt. b5 from one species has been shown to enhance the activity of CYP450 from another species, implying the involvement of non-specific interactions. These observations downplay the classical protein-protein biding based long range ET mechanism. Further, we provide evidence to show that murburn concept presents better chemico-physical logic for ETs mediated by Cyt. c and b5. To explain for the promiscuity of interactions, we conclude that the two proteins act as non-specific/generic redox capacitors, mediating a one-electron redox equilibrium involving diffusible reactive oxygen species (DROS) and ions.