A proper combination of implant materials for Total Ankle Replacement (TAR) may reduce stress at the bearing component and the resected surfaces of the tibia and talus, thus avoiding implant failure ...of the bearing component or aseptic loosening at the bone-implant interface.
A comprehensive finite element foot model implanted with the INBONE II implant system was created and the loading at the second peak of ground reaction force was simulated. Twelve material combinations including four materials for tibial and talar components (Ceramic, CoCrMo, Ti6Al4V, CFR-PEEK) and three materials for bearing components (CFR-PEEK, PEEK, and UHMWPE) were analyzed. Von Mises stress at the top and articular surfaces of the bearing component and the resected surfaces of the tibia and talus were recorded.
The stress at both the top and articular surfaces of the bearing component could be greatly reduced with more compliant bearing materials (44.76 to 72.77% difference of peak stress value), and to a lesser extent with more compliant materials for the tibial and talar components (0.94 to 28.09% difference of peak stress value). Peak stresses at both the tibial and talar bone-implant interface could be reduced more strongly by using tibial and talar component materials with smaller material stiffness (7.31 to 66.95% difference of peak stress value) compared with bearing materials with smaller material stiffness (1.11 to 24.77% difference of peak stress value).
Implant components with smaller material stiffness provided a stress reduction at the bearing component and resected surfaces of the tibia and talus. The selection of CFR-PEEK as the material of tibial and talar components and UHMWPE as the material of the bearing component seemed to be a promising material combination for TAR implants. Wear testing and long-term failure analysis of TAR implants with these materials should be included in future studies.
Highly dispersed supported gold with strong metal–support interaction is a desirable material for heterogeneous catalysis. Unlike current dispersion strategies of depositing gold from solution to ...support, we report herein a new method of producing highly dispersed gold clusters on ZnO mesocrystal. The gold clusters appeared on defect-rich twin-brush ZnO mesocrystals (TB-ZnO) via an in-and-out process: (i) a mixed Au/Zn oxide was formed first after deposition-precipitation of Au with AuCl4 –, (ii) fine Au clusters grow from the underneath to the surface of the oxide after heating. The TB-ZnO behaved like a sponge allowing gold atoms to heavily disperse into the wurtzite structure of ZnO with Zn-substitution by gold. After mild thermal treatment, the embedded gold emerged from underneath of the ZnO support to form highly dispersed Au nanoparticles of ∼2 nm on the ZnO surface. DFT calculation shows energetically favored Au-doping in TB-ZnO and facile defect-mediated migration of Au in it. The material (Au/TB-ZnO) gave outstanding activities for the catalysis of CO oxidation. The use of mesocrystals of metal oxide as supports, with rich vacancy defects, provides a new route for preparing highly dispersed and active supported metal catalysts.
A transition-metal-free intramolecular redox cyclization reaction for the synthesis of cinnolines has been developed from 2-nitrobenzyl alcohol and benzylamine. Mechanistic investigations disclosed ...the involvement of a key intramolecular redox reaction, followed by condensation, azo isomerization to hydrazone, cyclization, and aromatization to form the desired products. Notably, the formation of intermediate 2-nitrosobenzaldehyde and ( E )-2-(2-benzylidenehydrazineyl) benzaldehyde plays an important role in this transformation.
SIRT1 is a member of a highly conserved gene family (sirtuins) encoding nicotinamide adenine dinucleotide (NAD)+‐dependent deacetylases, originally found to deacetylate histones leading to increased ...DNA stability and prolonged survival in yeast and higher organisms, including mammals. SIRT1 has been found to function as a deacetylase for numerous protein targets involved in various cellular pathways, including stress responses, apoptosis and axonal degeneration. However, the role of SIRT1 in ultraviolet (UV) signalling pathways remains unknown. Using cell culture and Western blot analysis in this study we found that SIRT1 is expressed in cultured human skin keratinocytes. Both UV radiation and H2O2, two major inducers of skin cell damage, down‐regulate SIRT1 in a time‐ and dose‐dependent manner. We observed that reactive oxygen species‐mediated JNK activation is involved in this SIRT1 down‐regulation. SIRT1 activator, resveratrol, which has been considered as an important antioxidant, protects against UV‐ and H2O2‐induced cell death, whereas SIRT inhibitors such as sirtinol and nicotinamide enhance cell death. Activation of SIRT1 negatively regulates UV‐ and H2O2‐induced p53 acetylation, because nicotinamide and sirtinol as well as SIRT1 siRNA enhance UV‐ and H2O2‐induced p53 acetylation, whereas SIRT1 activator resveratrol inhibits it. We also found that SIRT1 is involved in UV‐induced AMP‐activated protein kinase (AMPK) and downstream acetyl‐CoA carboxylase (ACC), phosphofructose kinase‐2 (PFK‐2) phosphorylation. Collectively, our data provide new insights into understanding of the molecular mechanisms of UV‐induced skin aging, suggesting that SIRT1 activators such as resveratrol could serve as new anti‐skin aging agents.
The concentration of dissolved carbon dioxide in seawater affects the formation of seabed biogenic minerals, and controls the development and evolution of marine organisms, which is one of the most ...important indices in the marine environment and geology survey. The concentration of free carbon dioxide in bottom seawater has important academic value for the exploration of seabed minerals, marine environment monitoring, the study of the carbon cycle in seabed sediments and even the global carbon cycle. Titration is used to determine the index, whose range is between 4 mg/L and 400 mg/L. However, the concentration of free carbon dioxide in bottom seawater in some sea areas is lower than this range, thus titration may not be suitable. A method for the determination of free carbon dioxide in artificial seawater, whose name is D.B.S/Henry’s Law, is described in this paper. D.B.S/Henry’s Law indirectly determines the content of free carbon dioxide in seawater instead of directly titrating with reagents. It is simple, fast and accurate, and it is based on the law of conservation of mass/Henry’s law and CO2 dissolution mechanisms. This discovery mainly provides a new scientific perspective for the determination of trace free carbon dioxide concentration in seawater. In addition, Henry’s law constants of carbon dioxide in artificial seawater at 3–20 degrees Celsius are determined with D.B.S/Henry’s Law. These data will be used as an important reference for the determination of free carbon dioxide in seawater in the future. D.B.S/Henry’s Law may be used as a supplement of the methods specified in national and industrial standards, which are applied to the detection of carbon dioxide Henry’s constant and free carbon dioxide content in various temperature and salinity seawater. D.B.S/Henry’s Law provides a new perspective for CO2 determination and has extensive practical application value.
It is unclear whether the clinical benefits associated with non-vitamin K antagonist oral anticoagulants (NOACs) are similar to those associated with low-molecular-weight heparins (LMWHs) in Asian ...individuals with cancer and acute venous thromboembolism (VTE).
To compare the risk of recurrent thromboembolic events and bleeding associated with use of a NOAC vs use of the LMWH enoxaparin in Asian individuals with cancer-associated VTE.
This cohort study was conducted using data from the Chang Gung Research Database, a multi-institutional electronic medical records database in Taiwan. A cohort of 1109 patients with cancer-associated VTE were identified between January 1, 2012, and January 31, 2019. Data were analyzed from March 2019 through December 2020.
Receiving a NOAC (including rivaroxaban, apixaban, edoxaban, or dabigatran) or the LMWH enoxaparin.
The primary outcomes were composite recurrent VTE or major bleeding. Stabilized inverse probability of treatment weighting was used to balance baseline covariates. We compared risks of recurrent VTE or major bleeding between groups using Cox proportional hazards models. In addition, we conducted an analysis using a Fine and Gray subdistribution hazard model that considered death as a competing risk.
Among 1109 patients with cancer and newly diagnosed VTE, 578 (52.1%) were women and the mean (SD) age at index date was 66.0 (13.0) years; 529 patients (47.7%) received NOACs and 580 patients (52.3%) received the LMWH enoxaparin. Composite recurrent VTE or major bleeding occurred in 75 patients (14.1%) in the NOAC group and 101 patients (17.4%) in the enoxaparin group (weighted hazard ratio HR, 0.77; 95% CI, 0.56-1.07; P = .11). The groups had similar risk of VTE recurrence (HR, 0.62; 95% CI, 0.39-1.01; P = .05) and major bleeding (HR, 0.80; 95% CI, 0.52-1.24; P = .32) at 12 months of follow-up. However, taking a NOAC was associated with a significantly lower risk of gastrointestinal bleeding compared with receiving enoxaparin (10 patients 1.9% vs 41 patients 7.1%; HR, 0.29; 95% CI, 0.15-0.59; P < .001). Findings for both primary outcomes were consistent with competing risk analyses (recurrent VTE: HR, 0.68; 95% CI, 0.45-1.01; P = .05; major bleeding: HR, 0.77; 95% CI, 0.51-1.16; P = .21).
This cohort study found that in real-world practice, among Asian patients with cancer-associated VTE, use of a NOAC was associated with a similar risk for recurrent VTE or major bleeding compared with use of the LMWH enoxaparin. Nonetheless, use of a NOAC was associated with a significantly lower rate of gastrointestinal bleeding. Further prospective studies are needed to confirm these findings.
The best-characterized type 1 interferon (IFN) signaling pathway depends on signal transducer and activator of transcription 1 (STAT1) and STAT2. The cytokines can, however, conditionally activate ...all STATs. Regulation of their access to particular signaling pathways is poorly understood. STAT4 is important for IFN-gamma induction, and NK cells are major producers of this cytokine. We report that NK cells have high basal STAT4 levels and sensitivity to type 1 IFN-mediated STAT4 activation for IFN-gamma production. Increases in STAT1, driven during viral infection by either type 1 IFN or IFN-gamma, are associated with decreased STAT4 access. Both STAT1 and STAT2 are important for antiviral defense, but STAT1 has a unique role in protecting against sustained NK cell IFN-gamma production and resulting disease. The regulation occurs with an NK cell type 1 IFN receptor switch from a STAT4 to a STAT1 association. Thus, a fundamental characteristic of NK cells is high STAT4 bound to the type 1 IFN receptor. The conditions of infection result in STAT1 induction with displacement of STAT4. These studies elucidate the critical role of STAT4 levels in predisposing selection of specific signaling pathways, define the biological importance of regulation within particular cell lineages, and provide mechanistic insights for how this is accomplished in vivo.
We show that the spontaneous symmetry breaking in multiferroic hexagonal manganites can be chemically manipulated to yield two complementary ground states: the well-known ferroelectric P6(3)cm and an ...antipolar P3c phase. Both symmetry breakings yield topologically protected vortex defects, with the antipolar vortices dual to those of the ferroelectric. This duality stems from the existence of 12 possible angles of MnO5 tilting, and broad strain-free walls with low energy spontaneously emerge through an intermediate P3c1 state, providing a complete unified symmetry description.
In condensed matter physics, oxide materials show various intriguing physical properties. Therefore, many efforts are made in this field to develop functional oxides. Due to the excellent potential ...for tin‐based perovskite oxides, an expansion of new related functional compounds is crucial. This work uses a heteroepitaxial approach supported by theoretical calculation to stabilize PbSnO3 thin films with different orientations. The analyses of X‐ray diffraction and transmission electron microscopy unveil the structural information. A typical antiferroelectric feature with double hysteresis and butterfly loops is observed through electrical characterizations consistent with the theoretical prediction. The phase transition is monitored, and the transition temperatures are determined based on temperature‐dependent structural and electrical characterizations. Furthermore, the microscopic antiferroelectric order is noticed under atomic resolution images via scanning transmission electron microscopy. This work offers a breakthrough in synthesizing epitaxial PbSnO3 thin films and comprehensively understanding its anisotropic antiferroelectric behavior.
The epitaxial PbSnO3 (PSO) thin films with different orientations are stabilized by pulsed laser deposition. Through electrical measurement, the typical antiferroelectricity of PSO can be confirmed. In addition, the antiferroelectric order of PSO is unveiled by scanning transmission electron microscopy. This work offers an appealing approach in synthesizing PSO and deeply explores its characteristics.
A novel Gram-negative, aerobic, non-motile, ovoid to rod-shaped bacterium, designated NBD-18
, was isolated from a freshwater river in Taiwan. Optimal growth occurred at 30 °C, at pH 6 and in the ...absence of NaCl. The predominant fatty acids of strain NBD-18
were C
, summed feature 3 (C
7
and/or C
6
), C
cyclo and summed feature 8 (C
7
and/or C
6
). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidyldimethylethanolamine. The major polyamine was putrescine. The major isoprenoid quinone was Q-8. The genomic DNA G+C content of strain NBD-18
was 50.9 %. Strain NBD-18
was most closely related to
LMG 29303
and
HZ20
at a 16S rRNA gene sequence similarity of 97.7 %. 16S rRNA gene sequence similarity between
LMG 29303
and
HZ20
was 97.7 %. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set indicated that strain NBD-18
,
LMG 29303
and
HZ20
are affiliated with the same genus. Digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values among these three strains supported that they belong to the same genus and that strain NBD-18
represents a novel species. Thus,
HZ20
should be reclassified as
comb. nov. based on the rules for priority of publication and validation. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain NBD-18
represents a novel species in the genus
, for which the name
sp. nov. is proposed. The type strain is NBD-18
(=BCRC 81197
=LMG 31338
).
PDF
