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Nature Communications Jan 2024Aluminum alloys play an important role in circular metallurgy due to their good recyclability and 95% energy gain when made from scrap. Their low density and high...
Aluminum alloys play an important role in circular metallurgy due to their good recyclability and 95% energy gain when made from scrap. Their low density and high strength translate linearly to lower greenhouse gas emissions in transportation, and their excellent corrosion resistance enhances product longevity. The durability of Al alloys stems from the dense barrier oxide film strongly bonded to the surface, preventing further degradation. However, despite decades of research, the individual elemental reactions and their influence on the nanoscale characteristics of the oxide film during corrosion in multicomponent Al alloys remain unresolved questions. Here, we build up a direct correlation between the near-atomistic picture of the corrosion oxide film and the solute reactivity in the aqueous corrosion of a high-strength Al-Zn-Mg-Cu alloy. We reveal the formation of nanocrystalline Al oxide and highlight the solute partitioning between the oxide and the matrix and segregation to the internal interface. The sharp decrease in partitioning content of Mg in the peak-aged alloy emphasizes the impact of heat treatment on the oxide stability and corrosion kinetics. Through H isotopic labelling with deuterium, we provide direct evidence that the oxide acts as a trap for this element, pointing at the essential role of the Al oxide might act as a kinetic barrier in preventing H embrittlement. Our findings advance the mechanistic understanding of further improving the stability of Al oxide, guiding the design of corrosion-resistant alloys for potential applications.
PubMed: 38228660
DOI: 10.1038/s41467-024-44802-5 -
International Journal of Molecular... Dec 2023The impact of solubility on the toxicity of metal oxide nanoparticles (MONPs) requires further exploration to ascertain the impact of the dissolved and particulate...
The impact of solubility on the toxicity of metal oxide nanoparticles (MONPs) requires further exploration to ascertain the impact of the dissolved and particulate species on response. In this study, FE1 mouse lung epithelial cells were exposed for 2-48 h to 4 MONPs of varying solubility: zinc oxide, nickel oxide, aluminum oxide, and titanium dioxide, in addition to microparticle analogues and metal chloride equivalents. Previously published data from FE1 cells exposed for 2-48 h to copper oxide and copper chloride were examined in the context of exposures in the present study. Viability was assessed using Trypan Blue staining and transcriptomic responses via microarray analysis. Results indicate material solubility is not the sole property governing MONP toxicity. Transcriptional signaling through the 'HIF-1α Signaling' pathway describes the response to hypoxia, which also includes genes associated with processes such as oxidative stress and unfolded protein responses and represents a conserved response across all MONPs tested. The number of differentially expressed genes (DEGs) in this pathway correlated with apical toxicity, and a panel of the top ten ranked DEGs was constructed (Hmox1, Hspa1a, Hspa1b, Mmp10, Adm, Serpine1, Slc2a1, Egln1, Rasd1, Hk2), highlighting mechanistic differences among tested MONPs. The HIF-1α pathway is proposed as a biomarker of MONP exposure and toxicity that can help prioritize MONPs for further evaluation and guide specific testing strategies.
Topics: Animals; Mice; Copper; Oxides; Toxicogenetics; Chlorides; Metal Nanoparticles
PubMed: 38203705
DOI: 10.3390/ijms25010529 -
ACS Omega Oct 2023This research presents the results of the effect of different concentrations (2, 4, 6, and 8 wt %) of multiwall carbon nanotubes (MWCNTs) and aluminum oxide...
This research presents the results of the effect of different concentrations (2, 4, 6, and 8 wt %) of multiwall carbon nanotubes (MWCNTs) and aluminum oxide nanoparticles (AlO) on the characteristics of lithium-calcium grease (LCG). The LCG/AlO and LCG/MWCNT were studied and illustrated by measuring the dropping point, consistency, thermal conductivity, and tribological characteristics of nanograins (wear, friction, and welding point) by using a four-ball tribometer. The morphologies of the additives and the nanogrease were examined and evaluated by X-ray diffraction and transmission electron microscopy. The worn surface of the ball surface was assessed by scanning electron microscopy. Based on the obtained results, the nanoadditive can significantly enhance the grease properties. The grease having a 4 wt % content of AlO and MWCNT presented the lowest wear scar diameter and friction coefficient. Consequently, the welding point, dropping point, and thermal conductivity indicated that adding nanoadditives could strikingly enhance the lubricating effect of grease by 26, 32, and 75%, respectively. Finally, this study provides a lubricant with promising results that can be used under extreme pressure.
PubMed: 37901501
DOI: 10.1021/acsomega.3c03147 -
Science Advances Jan 2024Controlling the three-dimensional (3D) nanoarchitecture of inorganic materials is imperative for enabling their novel mechanical, optical, and electronic properties....
Controlling the three-dimensional (3D) nanoarchitecture of inorganic materials is imperative for enabling their novel mechanical, optical, and electronic properties. Here, by exploiting DNA-programmable assembly, we establish a general approach for realizing designed 3D ordered inorganic frameworks. Through inorganic templating of DNA frameworks by liquid- and vapor-phase infiltrations, we demonstrate successful nanofabrication of diverse classes of inorganic frameworks from metal, metal oxide and semiconductor materials, as well as their combinations, including zinc, aluminum, copper, molybdenum, tungsten, indium, tin, and platinum, and composites such as aluminum-doped zinc oxide, indium tin oxide, and platinum/aluminum-doped zinc oxide. The open 3D frameworks have features on the order of nanometers with architecture prescribed by the DNA frames and self-assembled lattice. Structural and spectroscopic studies reveal the composition and organization of diverse inorganic frameworks, as well as the optoelectronic properties of selected materials. The work paves the road toward establishing a 3D nanoscale lithography.
PubMed: 38198553
DOI: 10.1126/sciadv.adl0604 -
Nanomaterials (Basel, Switzerland) Dec 2023Alcohol ingested by humans can be analyzed via breath tests; however, approximately 1% can be excreted via the skin. In this paper, we present a capacitive sensor using...
Alcohol ingested by humans can be analyzed via breath tests; however, approximately 1% can be excreted via the skin. In this paper, we present a capacitive sensor using hydrophobically treated anodic aluminum oxide (AAO) capable of detecting alcohol excreted through the epidermis. The degree of hydrophobicity based on the duration of exposure to 3-aminopropyltriethoxysilane vapor comprising a small number of Si-NH functional groups on the AAO surface was confirmed and the optimal exposure time was confirmed to be 60 min. The hydrophobized AAO showed a 4.8% reduction in sensitivity to moisture. Simultaneously, the sensitivity of the sensor to ethanol decreased by only 12%. Lastly, the fabricated sensor was successfully operated by attaching it to an ankle-type breathalyzer.
PubMed: 38202525
DOI: 10.3390/nano14010070 -
European Review For Medical and... Oct 2023To evaluate the effects of various surface pretreatment methods, including H2SO4, Riboflavin, and Al2O3, as well as different luting cement types, namely Methyl... (Randomized Controlled Trial)
Randomized Controlled Trial
The impact of PEEK pretreatment using H2SO4, riboflavin, and aluminum trioxide on the extrusion bond strength to canal dentin luted with Polymethyl methacrylate and resin-based composite cement.
OBJECTIVE
To evaluate the effects of various surface pretreatment methods, including H2SO4, Riboflavin, and Al2O3, as well as different luting cement types, namely Methyl Methacrylate based Cement (MMBC) and composite-based cement (CBC), on the extrusion bond strength (EBS) of poly-ether-ether-ketone (PEEK) posts bonded to canal dentin.
MATERIALS AND METHODS
This study involved 120 single-rooted human premolar teeth that underwent endodontic treatment. Following root canal preparation, PEEK posts were fabricated from PEEK blanks using a CAD-CAM system, resulting in a total of 120 posts. The posts were randomly assigned to one of four groups based on their post-surface conditioning: Group A H2SO4, Group B RF, Group C Al2O3, and Group D (NC), each consisting of 30 posts. Within each group, there were two subgroups based on the type of luting cement used for bonding. Subgroups A1, B1, C1, and D1 (n=15 each) utilized CBC, while Subgroups A2, B2, C2, and D2 (n=15 each) used MMBC.The bond strength between the PEEK posts and root dentin was assessed using a universal testing machine, and the failure modes were examined under a stereomicroscope. Statistical analysis, including one-way analysis of variance (ANOVA) and Tukey's Post Hoc test with a significance level of p=0.05, was performed to analyze the data and evaluate the effects of surface treatment and luting cement type on the bond strength.
RESULTS
Group B2, which underwent RF conditioning followed by Super-Bond C&B cement application, exhibited the highest bond strength scores at the coronal section (9.57±0.67 MPa). On the other hand, Group D1, which had no conditioning (NC) and used Panavia® V5 cement, showed the lowest EBS at the apical third (2.39±0.72 MPa). The overall results indicate that the different conditioning regimens and luting cement types did not significantly influence the bond strength of PEEK posts to root dentin (p>0.05).
CONCLUSIONS
Riboflavin activated by photodynamic therapy (PDT) and H2SO4 can be effective surface conditioners for PEEK posts. These treatments have shown potential for enhancing the bond strength between PEEK and resin cement. Additionally, the study revealed that MMA-based cement outperformed composite-based cement in terms of bond integrity with PEEK posts.
Topics: Humans; Aluminum; Aluminum Oxide; Bone Cements; Composite Resins; Dentin; Ether; Ethers; Ethyl Ethers; Glass; Ketones; Materials Testing; Polymethyl Methacrylate; Riboflavin
PubMed: 37916329
DOI: 10.26355/eurrev_202310_34135 -
Plants (Basel, Switzerland) Aug 2023Selenium (Se)-enriched tea is a well-regarded natural beverage that is often consumed for its Se supplementation benefits. However, the production of this tea,...
Selenium (Se)-enriched tea is a well-regarded natural beverage that is often consumed for its Se supplementation benefits. However, the production of this tea, particularly in Se-abundant tea plantations, is challenging due to soil acidification. Therefore, this study aimed to investigate the effects of changes in Se under acidified soil conditions. Eight tea plantation soil monitoring sites in Southern Jiangsu were first selected. Simulated acid rain experiments and experiments with different acidification methods were designed and soil pH, as well as various Al-ion and Se-ion concentrations were systematically determined. The data were analyzed using R statistical software, and a correlation analysis was carried out. The results indicated that as the pH value dropped, exchangeable selenium (Exc-Se) and residual selenium (Res-Se) were transformed into acid-soluble selenium (Fmo-Se) and manganese oxide selenium (Om-Se). As the pH increased, exchange state aluminum (Alex) and water-soluble aluminum (Alw) decreased, Fmo-Se and Om-Se declined, and Exc-Se and Res-Se increased, a phenomenon attributed to the weakened substitution of Se ions by Al ions. In the simulated acid rain experiment, P1 compared to the control (CK), the pH value of the YJW tea plantation decreased by 0.13, Exc-Se decreased by 4 ug mg, Res-Se decreased by 54.65 ug kg, Fmo-Se increased by 2.78 ug mg, and Om-Se increased by 5.94 ug mg while Alex increased by 28.53 mg kg. The decrease in pH led to an increase in the content of Alex and Alw, which further resulted in the conversion of Exc-Se to Fmo-Se and Om-Se. In various acidification experiments, compared with CK, the pH value of T6 decreased by 0.23, Exc-Se content decreased by 8.35 ug kg, Res-Se content decreased by 40.62 ug kg, and Fmo-Se content increased by 15.52 ug kg while Alex increased by 33.67 mg kg, Alw increased by 1.7 mg kg, and Alh decreased by 573.89 mg kg. Acidification can trigger the conversion of Exc-Se to Fmo-Se and Om-Se, while the content of available Se may decrease due to the complexation interplay between Alex and Exc-Se. This study provides a theoretical basis for solving the problem of Se-enriched in tea caused by soil acidification.
PubMed: 37571035
DOI: 10.3390/plants12152882 -
Journal of Functional Biomaterials Oct 2023Achieving lightweight, high-strength, and biocompatible composites is a crucial objective in the field of tissue engineering. Intricate porous metallic structures, such... (Review)
Review
Achieving lightweight, high-strength, and biocompatible composites is a crucial objective in the field of tissue engineering. Intricate porous metallic structures, such as lattices, scaffolds, or triply periodic minimal surfaces (TPMSs), created via the selective laser melting (SLM) technique, are utilized as load-bearing matrices for filled ceramics. The primary metal alloys in this category are titanium-based Ti6Al4V and iron-based 316L, which can have either a uniform cell or a gradient structure. Well-known ceramics used in biomaterial applications include titanium dioxide (TiO), zirconium dioxide (ZrO), aluminum oxide (AlO), hydroxyapatite (HA), wollastonite (W), and tricalcium phosphate (TCP). To fill the structures fabricated by SLM, an appropriate ceramic is employed through the spark plasma sintering (SPS) method, making them suitable for in vitro or in vivo applications following minor post-processing. The combined SLM-SPS approach offers advantages, such as rapid design and prototyping, as well as assured densification and consolidation, although challenges persist in terms of large-scale structure and molding design. The individual or combined application of SLM and SPS processes can be implemented based on the specific requirements for fabricated sample size, shape complexity, densification, and mass productivity. This flexibility is a notable advantage offered by the combined processes of SLM and SPS. The present article provides an overview of metal-ceramic composites produced through SLM-SPS techniques. Mg-W-HA demonstrates promise for load-bearing biomedical applications, while Cu-TiO-Ag exhibits potential for virucidal activities. Moreover, a functionally graded lattice (FGL) structure, either in radial or longitudinal directions, offers enhanced advantages by allowing adjustability and control over porosity, roughness, strength, and material proportions within the composite.
PubMed: 37888186
DOI: 10.3390/jfb14100521 -
Research in Pharmaceutical Sciences 2023Bhamrung-Lohit (BRL) remedy is a traditional Thai medicine (TTM). There are few reports of biological activity, the activity of its constituent plants, or quantitative...
BACKGROUND AND PURPOSE
Bhamrung-Lohit (BRL) remedy is a traditional Thai medicine (TTM). There are few reports of biological activity, the activity of its constituent plants, or quantitative analytical methods for the content of phytochemicals. In this study, we investigated antioxidant, anti-inflammatory activity, and total phenolic and flavonoid content and validated a new analytical method for BRL.
EXPERIMENTAL APPROACH
Antioxidant activity was evaluated by a 2,2-diphenyl-1-picrylhydrazyl (DPPH and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging. The cellular antioxidant activity was evaluated by inhibition of the superoxide anion (O●-) production from HL-60 cells and anti-inflammatory activity by inhibition of nitric oxide production in RAW264.7 cells. The total phenolic and flavonoid contents were analyzed using the Folin-Ciocalteu method and an aluminum chloride colorimetric assay, respectively. Validated analytical procedures were conducted according to International Conference on Harmonization (ICH) guidelines.
FINDINGS/RESULTS
An ethanolic extract of BRL exerted potent DPPH radical scavenging activity and moderate antioxidant and anti-inflammatory activity. exerted the greatest effect and the highest content of total phenolics and flavonoids. The HPLC method validated parameters that complied with ICH requirements. Each peak showed selectivity with a baseline resolution of 2.0 and precision was less than 2.0% CV. The linearity of all compounds was > 0.999 and the recovery % was within 98.0%-102.0%. The validated results demonstrated specificity/selectivity, linearity, precision, and accuracy with appropriate LOD and LOQ.
CONCLUSION AND IMPLICATION
BRL remedy, a TTM demonstrated antioxidant and anti-inflammatory properties. This study is the first report on the biological activity and the validation of an HPLC method for BRL remedy.
PubMed: 37614616
DOI: 10.4103/1735-5362.378091 -
Nanomaterials (Basel, Switzerland) Jun 2023Random lasers have been studied using many materials, but only a couple have used glass matrices. Here, we present a study of zinc tellurite and aluminum oxide doped...
Random lasers have been studied using many materials, but only a couple have used glass matrices. Here, we present a study of zinc tellurite and aluminum oxide doped with different percentages of neodymium oxide (4 wt.%, 8 wt.%, and 16 wt.%) and demonstrate for the first time random laser action at 1337 nm. Laser emission was verified and the laser pulse's rise time and input-output power slope were obtained. A cavity composed of the sample's pump surface and an effective mirror formed by a second, parallel layer at the gain-loss boundary was probably the main lasing mechanism of this random laser system. The reason for the absence of emission at 1064 nm is thought to be a measured temperature rise in the samples' active volume.
PubMed: 37446488
DOI: 10.3390/nano13131972