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Microorganisms Aug 2023The COVID-19 pandemic highlighted the limitations in scientific and engineering understanding of applying germicidal UV to surfaces. This study combines surface...
The COVID-19 pandemic highlighted the limitations in scientific and engineering understanding of applying germicidal UV to surfaces. This study combines surface characterization, viral retention, and the related UV dose response to evaluate the effectiveness of UV as a viral inactivation technology on five surfaces: aluminum, ceramic, Formica laminate, PTFE and stainless steel. Images of each surface were determined using SEM (Scanning Electron Microscopy), which produced a detailed characterization of the surfaces at a nanometer scale. From the SEM images, the surface porosity of each material was calculated. Through further analysis, it was determined that surface porosity, surface roughness, contact angle, and zeta potential correlate to viral retention on the material. The imaging revealed that the aluminum surface, after repeated treatment, is highly oxidized, increasing surface area and surface porosity. These interactions are important as they prevent the recovery of MS-2 without exposure to UV. The dose response curve for PTFE was steeper than ceramic, Formica laminate and stainless steel, as inactivation to the detection limit was achieved at 25 mJ/cm. These findings are consistent with well-established literature indicating UV reflectivity of PTFE is maximized. Statistical testing reinforced that the efficacy of UV for surface inactivation varies by surface type.
PubMed: 37764001
DOI: 10.3390/microorganisms11092157 -
Cureus Dec 2023The wound-healing process incorporates a spectrum of periodontal therapeutic interventions that strive to restore the health and function of the periodontium....
BACKGROUND
The wound-healing process incorporates a spectrum of periodontal therapeutic interventions that strive to restore the health and function of the periodontium. Fibroblasts play pivotal roles in tissue repair and regeneration. Extensive research has been focused on mechanical and chemical root surface modifications to enhance fibroblast adhesion, which is crucial for successful wound healing.
PURPOSE
This study aimed to assess the combined efficacy of mechanical and chemical root surface modifications in promoting fibroblast viability to root surfaces affected by periodontitis in comparison to chemical modifications alone.
MATERIALS AND METHODS
Root samples were collected from healthy individuals and those with advanced periodontitis. The specimens were prepared, and the experimental groups were categorized based on the type of surface modification with mechanical and/or chemical materials, including hyaluronic acid (HA), ethylenediaminetetraacetic acid (EDTA), enamel matrix derivatives (EMD), and EDTA/EMD. Fibroblasts were seeded onto previously treated root samples. Cell adhesion was assessed using a viability assay.
RESULTS
Fibroblast viability was significantly higher on root surfaces treated with chemical agents than on those treated with mechanical and chemical modifications. Long-duration EDTA and short-duration EMD treatments were significantly effective in enhancing cell viability. EDTA/EMD surface treatments resulted in significantly higher cell viability in all groups compared to the periodontitis root surfaces.
CONCLUSION
EDTA, EMD, and their combined application can potentially ameliorate periodontitis-induced surface structural impairments. Mechanical surface debridement can significantly affect the effectiveness of EDTA and EMD root conditioning agents.
PubMed: 38213353
DOI: 10.7759/cureus.50381 -
Nature Jan 2024The large-scale conversion of N and H into NH (refs. ) over Fe and Ru catalysts for fertilizer production occurs through the Haber-Bosch process, which has been...
The large-scale conversion of N and H into NH (refs. ) over Fe and Ru catalysts for fertilizer production occurs through the Haber-Bosch process, which has been considered the most important scientific invention of the twentieth century. The active component of the catalyst enabling the conversion was variously considered to be the oxide, nitride, metallic phase or surface nitride, and the rate-limiting step has been associated with N dissociation, reaction of the adsorbed nitrogen and also NH desorption. This range of views reflects that the Haber-Bosch process operates at high temperatures and pressures, whereas surface-sensitive techniques that might differentiate between different mechanistic proposals require vacuum conditions. Mechanistic studies have accordingly long been limited to theoretical calculations. Here we use X-ray photoelectron spectroscopy-capable of revealing the chemical state of catalytic surfaces and recently adapted to operando investigations of methanol and Fischer-Tropsch synthesis-to determine the surface composition of Fe and Ru catalysts during NH production at pressures up to 1 bar and temperatures as high as 723 K. We find that, although flat and stepped Fe surfaces and Ru single-crystal surfaces all remain metallic, the latter are almost adsorbate free, whereas Fe catalysts retain a small amount of adsorbed N and develop at lower temperatures high amine (NH) coverages on the stepped surfaces. These observations indicate that the rate-limiting step on Ru is always N dissociation. On Fe catalysts, by contrast and as predicted by theory, hydrogenation of adsorbed N atoms is less efficient to the extent that the rate-limiting step switches following temperature lowering from N dissociation to the hydrogenation of surface species.
PubMed: 38200297
DOI: 10.1038/s41586-023-06844-5 -
Journal of Applied Crystallography Oct 2023X-ray diffraction techniques are widely used to estimate stresses within polycrystalline materials. The application of these techniques requires the knowledge of the...
X-ray diffraction techniques are widely used to estimate stresses within polycrystalline materials. The application of these techniques requires the knowledge of the X-ray elastic constants relating the lattice strains to the stress state. Different analytical methods have been proposed to evaluate the X-ray elastic constants from the single-crystal elastic constants. For a given material, such methods provide the bulk X-ray elastic constants but they do not consider the role of free surfaces. However, for many practical applications of X-ray diffraction techniques, the penetration depth of X-rays is the same order of magnitude as the grain size, which means that the influence of the free surface on X-ray elastic constants cannot be excluded. In the present work, a numerical procedure is proposed to evaluate the surface and bulk X-ray elastic constants of polycrystalline materials. While the former correspond to the situation where the penetration is infinitely small in comparison with the grain size, the latter are representative of an infinite penetration depth with no free-surface effect. According to numerical results, the difference between surface and bulk X-ray elastic constants is important for strongly anisotropic crystals. Also, it is possible to propose a relation that allows evaluating X-ray elastic constants as a function of the ratio between the penetration depth and the average grain size. The corresponding parameters of such a relation are provided here for many engineering materials.
PubMed: 37791353
DOI: 10.1107/S1600576723006878 -
Advances in Neural Information... Dec 2023Accurate reconstruction of cortical surfaces from brain magnetic resonance images (MRIs) remains a challenging task due to the notorious partial volume effect in brain...
Accurate reconstruction of cortical surfaces from brain magnetic resonance images (MRIs) remains a challenging task due to the notorious partial volume effect in brain MRIs and the cerebral cortex's thin and highly folded patterns. Although many promising deep learning-based cortical surface reconstruction methods have been developed, they typically fail to model the interdependence between inner (white matter) and outer (pial) cortical surfaces, which can help generate cortical surfaces with spherical topology. To robustly reconstruct the cortical surfaces with topological correctness, we develop a new deep learning framework to jointly reconstruct the inner, outer, and their in-between (midthickness) surfaces and estimate cortical thickness directly from 3D MRIs. Our method first estimates the midthickness surface and then learns three diffeomorphic flows jointly to optimize the midthickness surface and deform it inward and outward to the inner and outer cortical surfaces respectively, regularized by topological correctness. Our method also outputs a cortex thickness value for each surface vertex, estimated from its diffeomorphic deformation trajectory. Our method has been evaluated on two large-scale neuroimaging datasets, including ADNI and OASIS, achieving state-of-the-art cortical surface reconstruction performance in terms of accuracy, surface regularity, and computation efficiency.
PubMed: 38835722
DOI: No ID Found -
Polymers Apr 2024The goal of the study was to compare the surface characteristics of typical implant materials used in orthopedic surgery and traumatology, as these determine their...
The goal of the study was to compare the surface characteristics of typical implant materials used in orthopedic surgery and traumatology, as these determine their successful biointegration. The morphological and chemical structure of Vortex plate anodized titanium from commercially pure (CP) Grade 2 Titanium (Ti2) is generally used in the following; non-cemented total hip replacement (THR) stem and cup Ti alloy (Ti6Al4V) with titanium plasma spray (TPS) coating; cemented THR stem Stainless steel (SS); total knee replacement (TKR) femoral component CoCrMo alloy (CoCr); cemented acetabular component from highly cross-linked ultrahigh molecular weight polyethylene (HXL); and cementless acetabular liner from ultrahigh molecular weight polyethylene (UHMWPE) (Sanatmetal, Ltd., Eger, Hungary) discs, all of which were examined. Visualization and elemental analysis were carried out by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Surface roughness was determined by atomic force microscopy (AFM) and profilometry. TPS Ti presented the highest R value (25 ± 2 μm), followed by CoCr (535 ± 19 nm), Ti2 (227 ± 15 nm) and SS (170 ± 11 nm). The roughness measured in the HXL and UHMWPE surfaces was in the same range, 147 ± 13 nm and 144 ± 15 nm, respectively. EDS confirmed typical elements regarding the investigated prosthesis materials. XPS results supported the EDS results and revealed a high % of Ti on Ti2 and TPS surfaces. The results indicate that the surfaces of prosthesis materials have significantly different features, and a detailed characterization is needed to successfully apply them in orthopedic surgery and traumatology.
PubMed: 38732662
DOI: 10.3390/polym16091193 -
RSC Advances Apr 2024Surface coating technology is broadly demanded across various fields, including marine and biomedical materials; therefore, a facile and versatile approach is desired....
Surface coating technology is broadly demanded across various fields, including marine and biomedical materials; therefore, a facile and versatile approach is desired. This study proposed an attractive surface coating strategy using photo-crosslinkable benzophenone (BP) moiety for biomaterials application. BP-containing "bioglue" polymer can effectively crosslink with all kinds of surfaces and biomolecules. Upon exposure to ultraviolet (UV) light, free radical reaction from the BP glue facilitates the immobilization of diverse molecules onto different substrates in a straightforward and user-friendly manner. Through either one-step, mixing the bioglue with targeted biomolecules, or two-step methods, pre-coating the bioglue and then adding targeted biomolecules, polyacrylic acid (PAA), cyclic RGD-containing peptides, and proteins (gelatin, collagen, and fibronectin) were successfully immobilized on substrates. After drying the bioglue, targeted biomolecules can still be immobilized on the surfaces preserving their bioactivity. Cell culture on biomolecule-immobilized surfaces using NIH 3T3 fibroblasts and human bone marrow stem cells (hBMSCs) showed significant improvement of cell adhesion and activity compared to the unmodified control in serum-free media after 24 hours. Furthermore, hBMSCs on the fibronectin-immobilized surface showed an increased calcium deposition after 21 days of osteogenic differentiation, suggesting that the immobilized fibronectin is highly bioactive. Given the straightforward protocol and substrate-independent bioglue, the proposed coating strategy is promising in broad-range fields.
PubMed: 38655476
DOI: 10.1039/d4ra01866d -
Frontiers in Microbiology 2023Monkeypox virus (MPXV), which causes Monkeypox (Mpox), has recently been found outside its usual geographic distribution and has spread to 117 different nations. The... (Review)
Review
Monkeypox virus (MPXV), which causes Monkeypox (Mpox), has recently been found outside its usual geographic distribution and has spread to 117 different nations. The World Health Organization (WHO) designated the epidemic a Public Health Emergency of International Concern (PHEIC). Humans are at risk from MPXV's spread, which has raised concerns, particularly in the wake of the SARS-CoV-2 epidemic. The risk of virus transmission may rise due to the persistence of MPXV on surfaces or in wastewater. The risk of infection may also increase due to insufficient wastewater treatment allowing the virus to survive in the environment. To manage the infection cycle, it is essential to investigate the viral shedding from various lesions, the persistence of MPXV on multiple surfaces, and the length of surface contamination. Environmental contamination may contribute to virus persistence and future infection transmission. The best possible infection control and disinfection techniques depend on this knowledge. It is thought to spread mainly through intimate contact. However, the idea of virus transmission by environmental contamination creates great concern and discussion. There are more cases of environmental surfaces and wastewater contamination. We will talk about wastewater contamination, methods of disinfection, and the present wastewater treatment in this review as well as the persistence of MPXV on various environmental surfaces.
PubMed: 38179458
DOI: 10.3389/fmicb.2023.1272498 -
Nanomaterials (Basel, Switzerland) Feb 2024Wettability, typically estimated through the contact angle, is a fundamental property of surfaces with wide-ranging implications in both daily life and industrial...
Wettability, typically estimated through the contact angle, is a fundamental property of surfaces with wide-ranging implications in both daily life and industrial processes. Recent scientific interest has been paid to the surfaces exhibiting extreme wettability: superhydrophobic and superhydrophilic surfaces, characterized by high water repellency and exceptional water wetting, respectively. Both chemical composition and morphology play a role in the determination of the wettability "performance" of a surface. To tune surface-wetting properties, we considered coatings of carbon nanoparticles (CNPs) in this study. They are a new class of nanomaterials synthesized in flames whose chemistry, dimension, and shape depend on combustion conditions. For the first time, we systematically studied the wettability of CNP coatings produced in a controlled rich ethylene/air flame stabilized over a McKenna burner. A selected substrate was intermittently inserted in the flame at 15 mm above the burner to form a thin coating thanks to a thermophoretic-driven deposition mechanism. The chemical-physical quality and the deposed quantity of the CNPs were varied by opportunely combing the substrate flame insertion number (from 1 to 256) and the carbon-to-oxygen ratio, C/O (from 0.67 to 0.87). The wettability of the coatings was evaluated by measuring the contact angle, CA, with the sessile drop method. When the C/O = 0.67, the CNPs were nearly spherical, smaller than 8 nm, and always generated hydrophilic coatings (CA < 35°). At higher C/O ratios, the CNPs reached dimensions of 100 nm, and fractal shape aggregates were formed. In this case, either hydrophilic (CA < 76°) or superhydrophobic (CA ~166°) behavior was observed, depending on the number of carbon nanoparticles deposed, i.e., film thickness. It is known that wettability is susceptible to liquid surface tension, and therefore, tests were conducted with different fluids to establish a correlation between the flame conditions and the nanostructure of the film. This method offers a fast and simple approach to determining mesoscale information for coating roughness and topographical homogeneity/inhomogeneity of their surfaces.
PubMed: 38334572
DOI: 10.3390/nano14030301 -
Micromachines Feb 2024This overview intends to provide a comprehensive assessment of the novel fluids and the current techniques for surface modification for pool boiling enhancement. The... (Review)
Review
This overview intends to provide a comprehensive assessment of the novel fluids and the current techniques for surface modification for pool boiling enhancement. The surface modification at macro-, micro-, and nanoscales is assessed concerning the underlying fluid routing and capability to eliminate the incipient boiling hysteresis and ameliorate the pool boiling heat-transfer ability, particularly when employed together with self-rewetting fluids and nanofluids with enriched thermophysical properties. Considering the nanofluids, it is viable to take the profit of their high thermal conductivity and their specific heat simultaneously and to produce a film of deposited nanoparticles onto the heating surface, which possesses enhanced surface roughness and an increased density of nucleation sites. Whilst the diverse improvement scales are found to achieve distinct levels of success regarding the nucleate boiling heat-transfer capability enhancement, it is also shown that the micro-nanoscale boiling surface features are susceptible to blockage, leading to the degradation of the improvement with time. Furthermore, topics relating to the heat transfer thermal behavior, ease of manufacture, cost-effectiveness, reliability, and durability are reviewed whenever available and challenges and recommendations for further research are highlighted.
PubMed: 38542549
DOI: 10.3390/mi15030302