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MXenes, a class of two-dimensional (2D) transition-metal carbides, nitrides, and carbonitrides, exhibit promising tribological properties at the nanoscale. However, the influence of X elements on the surface chemistry of MXene atomic layers remains underexplored. Here, we investigate how nitrogen in the TiCN atomic layer modifies its nanotribological behavior compared to TiC. Using friction force microscopy and peak force quantitative nanomechanics , we find that TiCN exhibits a notable increase in friction along with higher adhesion and energy dissipation, which we attribute to enhanced hydroxyl termination, stronger surface dipole interactions, and hydrogen bonding. X-ray photoelectron spectroscopy further reveals that nitrogen incorporation leads to greater electron withdrawal from titanium atoms, resulting in a higher oxidation state and altered surface chemical functionality. These results provide mechanistic insight into how X-element chemistry influences the tribological performance of MXenes, highlighting the importance of surface composition in designing 2D materials for specific applications.
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http://dx.doi.org/10.1021/acs.nanolett.5c02270 | DOI Listing |
J Trace Elem Med Biol
September 2025
Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, Kraków 31-343, Poland. Electronic address:
Vanadium (V) is a trace element in the environment; it is detected in soil, water, air, dust, and food products. V-containing compounds have shown therapeutic potential in the treatment of diabetes. However, studies on the effects of V on animal behavior remain limited and sporadic.
View Article and Find Full Text PDFJ Trace Elem Med Biol
September 2025
Department of Neurology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China. Electronic address:
Objective: We previously documented that exposure to a spectrum of elements is associated with autism spectrum disorder (ASD). However, there is a lack of mechanistic understanding as to how elemental mixtures contribute to the ASD development.
Materials And Methods: Serum and urinary concentrations of 26 elements and six biomarkers of ASD-relevant pathophysiologic pathways including serum HIPK 2, serum p53 protein, urine malondialdehyde (MDA), urine 8-OHdG, serum melatonin, and urine carnitine, were measured in 21 ASD cases and 21 age-matched healthy controls of children aged 6-12 years.
Braz Oral Res
September 2025
Universidade Federal do Rio Grande do Norte -UFRN, Department of Dentistry, Natal, RN, Brazil.
This study aimed to histomorphometrically evaluate the effect of guided bone regeneration (GBR) and two implant surfaces on the thickness and height of newly formed bone in dehiscence defects around titanium implants. Three premolars and the first bilateral molar were extracted from ten adult mongrel dogs, and 40 buccal bone dehiscences measuring 5 mm in height and 4 mm in width were created using a University of North Carolina (UNC) periodontal probe to confirm the dimensions. Forty implants were randomly assigned to one of four groups: oxidized implant surfaces (OIS, n = 10), turned/machined implant surfaces (TIS, n = 10), OIS + GBR (n = 10), and TIS + GBR (n = 10).
View Article and Find Full Text PDFClin Orthop Relat Res
August 2025
Complex Joint Reconstruction Center, Hospital for Special Surgery, New York, NY, USA.
Background: Choosing the appropriate implants for reconstruction in revision TKA is essential for long-term fixation. While cones and augments are routinely utilized to address tibial defects, the effect of augment location and size on the biomechanical stability of revision TKA constructs and the indications for the use of metaphyseal cones are not known.
Questions/purposes: Is the risk of cement-implant debonding of revision TKA constructs impacted by the thickness and location (medial versus bicompartmental) of tibial augments and the presence of metaphyseal cones during (1) a demanding daily activity like stair ascent and (2) torsional loads?
Methods: Under institutional review board approval, we developed patient-specific finite-element models of revision TKA from four patients (three males and one female, ages 50 to 80 years, BMI 27 to 37 kg/m2) who underwent two-stage revision and had a CT scan with no metal artifact after first-stage implant removal.
Elife
September 2025
Human Biology and Primate Evolution, Institute of Biology, Freie Universität Berlin, Berlin, Germany.
Evidence indicates that transposable elements (TEs) can contribute to the evolution of new traits, with some TEs acting as deleterious elements while others are repurposed for beneficial roles in evolution. In mammals, some KRAB-ZNF proteins can serve as a key defense mechanism to repress TEs, offering genomic protection. Notably, the family of KRAB-ZNF genes evolves rapidly and exhibits diverse expression patterns in primate brains, where some TEs, including autonomous LINE-1 and non-autonomous Alu and SVA elements, remain mobile.
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