Microwave-assisted solvothermal synthesis of nanostructured Ga-Doped Li7La3Zr2O12 solid electrolyte with enhanced densification and Li-ion conductivity.

Garnet-type Li7La3Zr2O12 (LLZO) Li-ion solid electrolytes are promising candidates for safe, next-generation solid-state batteries. In this study, we synthesize Ga-doped LLZO (Ga-LLZO) electrolytes using a microwave-assisted solvothermal method followed by low-temperature heat treatment. The nanostructured precursor (<50 nm) produced by the microwave-assisted solvothermal process has a high surface energy, facilitating the reaction for preparing garnet-type Ga-LLZO powders (<800 nm) within a short time (<5 h) at a low calcination temperature (<700 °C). Additionally, the calcined nanostructured Ga-LLZO powder can be sintered to produce a high-density pellet with minimized grain boundaries under moderate sintering conditions (temperature: 1150 °C, duration: 10 h). The optimal doping concentration was determined to be 0.4 mol% Ga, which resulted significantly increased the ionic conductivity (1.04 × 10-3 S cm-1 at 25 °C) and stabilized the cycling performance over 1700 h at 0.4 mA cm-2. This approach demonstrates the potential to synthesize oxide-type solid electrolyte materials with improved properties for solid-state batteries.

Increasing ductility beyond post-uniform deformation through Zn lamellae deformation in Al at room temperature.

The Zn element precipitates during aging in the Al-Zn binary alloy. Increased Zn content and prolonged aging leads to discontinuous Zn precipitation. The addition of 2 wt% Cu to the Al-43 wt%Zn alloy accelerates this discontinuous precipitation, resulting in decreased thickness of Zn layers and inter-distance between them. This acceleration is attributed to the influence of Cu solutes on the Zn phase, thereby reducing the interface energy between Zn precipitates and the Al matrix. The Al-Zn-Cu alloy demonstrates exceptional behavior during tensile tests, displaying a simultaneous increase in tensile strength and ductility alongside an 75 % reduction in area at room temperature drawing. Notably, despite the drawn beyond uniform deformation limit, there is an observed increase in total elongation. Our demonstration highlights this phenomenon, attributing it to the sustained coherent interface between the Zn layer and the Al matrix, as well as the uninterrupted continuity of Zn layers during drawing.

Oral Ingestion of AP Collagen Peptide Leads to Systemic Absorption of Gly-Pro-Hyp, Alleviating H2O2-Induced Dermal Fibroblast Aging.

Collagen-derived dipeptides and tripeptides have various physiological activities. In this study, we compared the plasma kinetics of free Hyp, peptide-derived Hyp, Pro-Hyp, cyclo(Pro-Hyp), Hyp-Gly, Gly-Pro-Hyp, and Gly-Pro-Ala after ingestion of four different collagen samples: AP collagen peptide (APCP), general collagen peptide, collagen, and APCP and γ-aminobutyric acid (GABA) combination. Each peptide was measured by high-performance liquid chromatography and triple quadrupole mass spectrometer. We found that, among all the peptides that were analyzed, only Gly-Pro-Hyp was significantly increased after ingestion of APCP compared with that of general collagen peptides and collagen. In addition, ingestion of the APCP and GABA combination improved the absorption efficiency of Gly-Pro-Ala. Finally, we reveal that Gly-Pro-Hyp was effective for preventing H2O2-induced reduction in extracellular matrix (ECM)-related genes, COL1A, elastin, and fibronectin, in dermal fibroblasts. Taken together, APCP significantly enhances the absorption of Gly-Pro-Hyp, which might act as an ECM-associated signaling factor in dermal fibroblasts, and the APCP and GABA combination promotes Gly-Pro-Ala absorption. Clinical Trial Registration number: UMIN000047972.

Oral Intake of Enzymatically Decomposed AP Collagen Peptides Improves Skin Moisture and Ceramide and Natural Moisturizing Factor Contents in the Stratum Corneum.

The stratum corneum (SC) is the outermost layer of the epidermis and plays an important role in maintaining skin moisture and protecting the skin from the external environment. Ceramide and natural moisturizing factor (NMF) are the major SC components that maintain skin moisture. In this study, we investigated whether the oral intake of enzymatically decomposed AP collagen peptides (APCPs) can improve skin moisture and barrier function by assessing changes in the ceramide and NMF contents in the SC after APCP ingestion with the aim to develop a skin functional food. Fifty participants orally ingested APCP (1000 mg) or placebo for 12 weeks, and then, skin hydration and skin texture were evaluated. SC samples were collected to analyze skin scaling, ceramide, and NMF contents. Participants in the APCP group exhibited improved skin moisture content by 7.33% (p = 0.031) and roughness by -4.09% (p = 0.036) when compared with those in the placebo group. NMF content; the amounts of amino acids (AA), including glycine and proline; and AA derivatives were significantly increased in the APCP group (31.98 µg/mg protein) compared to those in the placebo group (-16.01 µg/mg protein) (p = 0.006). The amounts of total ceramides and ceramide subclasses were significantly higher in the APCP group than in the placebo group (p = 0.014). In conclusion, our results demonstrate that APCP intake improves skin moisture and increase the ceramide and NMF contents in the SC, thereby enhancing the skin barrier function.

Audiologic outcomes and complications of active middle ear implantation in older adults.

BACKGROUND: A few studies have reported the use of middle ear implants (MEIs) in older adults. OBJECTIVES: To evaluate the audiologic outcomes and postoperative complications of MEIs in older adults. METHODS: This retrospective study reviewed audiologic data and medical records from a single referral centre. We identified 34 patients aged ≥65 years who underwent middle ear implantation using the Vibrant SoundbridgeTM device. Preoperative audiometric testing and postoperative aided audiometric testing were performed to evaluate the functional hearing gain at 1 year postoperatively. Patients were divided into 2 groups depending on whether they underwent explantation because of poor hearing benefit. RESULTS: Follow-up duration ranged from <1 to 5.3 years. The functional gain with MEIs significantly improved relative to the preoperative air conduction thresholds at 0.5, 1, 2, and 4 kHz. Eight patients underwent explantation and 7 lost their external audio processor devices. Those who removed their implants because of the poor hearing (group 1) showed significantly worse hearing thresholds at 1 kHz and speech discrimination scores than the others (group 2). CONCLUSIONS AND SIGNIFICANCE: MEIs for auditory rehabilitation can provide improved speech recognition and significant functional gains in older adults. Patients must be given appropriate preoperative explanations regarding the expected outcomes.

AP Collagen Peptides Prevent Cortisol-Induced Decrease of Collagen Type I in Human Dermal Fibroblasts.

Cortisol is an endogenous glucocorticoid (GC) and primary stress hormone that regulates a wide range of stress responses in humans. The adverse effects of cortisol on the skin have been extensively documented but the underlying mechanism of cortisol-induced signaling is still unclear. In the present study, we investigate the effect of cortisol on collagen type I expression and the effect of AP collagen peptides, collagen tripeptide-rich hydrolysates containing 3% glycine-proline- hydroxyproline (Gly-Pro-Hyp, GPH) from the fish skin, on the cortisol-mediated inhibition of collagen type I and the cortisol-induced signaling that regulates collagen type I production in human dermal fibroblasts (HDFs). We determine that cortisol downregulates the expression of collagen type I. AP collagen peptides or GC receptor (GR) inhibitors recover the cortisol-mediated inhibition of collagen type I and GR activation. AP collagen peptides or GR inhibitors also prevent the cortisol-dependent inhibition of transforming growth factor (TGF)-ß signaling. AP collagen peptides or GR inhibitors are effective in the prevention of collagen type I inhibition mediated by cortisol in senescent HDFs and reconstituted human skin models. Taken together, GR signaling might be responsible for the cortisol-mediated inhibition of TGF-ß. AP collagen peptides act as GR-mediated signaling blockers, preventing the cortisol-dependent inhibition of collagen type I. Therefore, AP collagen peptides have the potential to improve skin health.

Effect of healthcare benefits on short-term adherence of positive airway pressure therapy.

PURPOSE: The objective of this study was to assess the impact of healthcare benefits on adherence to positive airway pressure (PAP) therapy in obstructive sleep apnea (OSA) patients. METHODS: Medical records of OSA patients at the Veterans Health Service Medical Center were retrospectively reviewed. OSA patients were assigned to two groups as the date of prescribing PAP: after (=Group A) and before (=Group B) July 1, 2018 when PAP therapy starts to be included in healthcare insurance coverage for OSA patients in South Korea. PAP adherence was compared over a 3-month period between the two groups; subjective improvement after therapy was evaluated using the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index scores. In addition, we evaluated a number of OSA patients who chose to start PAP therapy without healthcare benefit (from July 2018 to December 2018). RESULTS: Each of the 50 patients in the Group A and B exhibited PAP adherence rates of 82% and 26%, respectively (P < .001). Age did not affect PAP adherence in the Group A. The mean apnea-hypopnea index (from 36.7 to 1.34, P < .001) and ESS (from 7.6 to 5.6, P = .004) scores of patients in the Group A had significantly improved within the first three months. Twenty-three (23 out of 334, 6.9%) OSA patients did not have any healthcare insurance, but they medically needed PAP therapy. However, only one of the 23 patients began PAP treatment. CONCLUSION: Short-term PAP adherence significantly improved after PAP therapy was included in healthcare insurance coverage.

Spontaneous Formation of Highly Stable Nanoparticle Supercrystals Driven by a Covalent Bonding Interaction.

Nanoparticle supercrystals (NPSCs) are of great interest as materials with emergent properties. Different types of intermolecular forces, such as van der Waals interaction and hydrogen bonding, are present in the NPSCs fabricated to date. However, the limited structural stability of such NPSCs that results from the weakness of these intermolecular forces is a challenge. Here, we report a spontaneous formation of NPSCs driven by covalent bonding interactions, a type of intramolecular force much stronger than the above-mentioned intermolecular forces. A model solution-phase anhydride reaction is used to form covalent bonds between molecules grafted on the surface of gold nanoparticles, resulting in three-dimensional NPSCs. The NPSCs are very stable in different solvents, in dried conditions, and at temperatures as high as 160 °C. In addition to this, the large library of covalent-bond-forming reactions available and the low cost of reactants make the covalent bonding approach highly versatile and economical.

Electromagnetic and optical responses of a composite material comprising individual single-walled carbon-nanotubes with a polymer coating.

The composites and thin films comprising individual single-walled carbon nanotubes with a polymer coating (p-CNTs) have been prepared and their electromagnetic responses have been studied in a wide range from low-frequency (25-107 Hz) up to the infrared region. In spite of the high volume fraction of the nanotubes (up to 3.3%), the polymer coating prevents direct p-CNT contacts and the formation of the percolation network in those composites, so that p-CNTs interact only via the electromagnetic coupling. Thereby it is an ideal model system to verify experimentally the fundamental issues related to carbon nanotube electromagnetics, such as the influence of inter-tube electron tunneling on the localized plasmon resonance in the terahertz range, or the infrared absorption enhancement of polymer molecules attached to the nanotube surface. Along with addressing the fundamentals, applied carbon nanotube electromagnetics got insights important for the applications of p-CNT based composites as dielectric media in the terahertz regime. In particular, we found that the real part of the permittivity of the p-CNT film in the terahertz range is rather competitive, i.e. 8-13, however the loss tangent is not so small (0.4-0.6) as has been predicted. The way to increase p-CNT terahertz performance is also discussed.

Micelle-Assisted Formation of Nanoparticle Superlattices and Thermally Reversible Symmetry Transitions.

Nanoparticle superlattices (NPSLs) are of great interest as materials with designed emerging properties depending on the lattice symmetry as well as composition. The symmetry transition of NPSLs depending on environmental conditions can be an excellent ground for making new stimuli-responsive functional materials. Here, we report a spherical micelle-assisted method to form exceptionally ordered NPSLs which are inherently sensitive to environmental conditions. Upon mixing functionalized gold nanoparticles (AuNPs) with a nonionic surfactant spherical micellar solution, NPSLs of different symmetries such as NaZn13, MgZn2, and AlB2-type are formed depending on the size ratio between micelles and functionalized AuNPs and composition. The NPSLs formed by the spherical micelle-assisted method show thermally reversible order-order (NaZn13-AlB2) and order-disorder (MgZn2-isotropic) symmetry transitions, which are consistent with the Gibbs free energy calculations for binary hard-sphere model. This approach may open up new possibilities for NPSLs as stimuli-responsive functional materials.

Simultaneous increase in strength and ductility by decreasing interface energy between Zn and Al phases in cast Al-Zn-Cu alloy.

Cast-Al alloys that include a high amount of the second element in their matrix have comparatively high strength but low ductility because of the high volume fraction of strengthening phases or undesirable inclusions. Al-Zn alloys that have more than 30 wt% Zn have a tensile strength below 300 MPa, with elongation under 5% in the as-cast state. However, we found that after substitution of 2% Zn by Cu, the tensile strength of as-cast Al-Zn-Cu alloys was 25% higher and ductility was four times higher than for the corresponding Al-35% Zn alloy. Additionally, for the Al-43% Zn alloy with 2% Cu after 1 h solution treatment at 400 °C and water quenching, the tensile strength unexpectedly reached values close to 600 MPa. For the Al-33% Zn alloy with 2% Cu, the tensile strength was 500 MPa with 8% ductility. The unusual trends of the mechanical properties of Al-Zn alloys with Cu addition observed during processing from casting to the subsequent solution treatment were attributed to the precipitation of Zn in the Al matrix. The interface energy between the Zn particles and the Al matrix decreased when using a solution of Cu in Zn.

Hierarchically self-assembled hexagonal honeycomb and kagome superlattices of binary 1D colloids.

Synthesis of binary nanoparticle superlattices has attracted attention for a broad spectrum of potential applications. However, this has remained challenging for one-dimensional nanoparticle systems. In this study, we investigate the packing behavior of one-dimensional nanoparticles of different diameters into a hexagonally packed cylindrical micellar system and demonstrate that binary one-dimensional nanoparticle superlattices of two different symmetries can be obtained by tuning particle diameter and mixing ratios. The hexagonal arrays of one-dimensional nanoparticles are embedded in the honeycomb lattices (for AB2 type) or kagome lattices (for AB3 type) of micellar cylinders. The maximization of free volume entropy is considered as the main driving force for the formation of superlattices, which is well supported by our theoretical free energy calculations. Our approach provides a route for fabricating binary one-dimensional nanoparticle superlattices and may be applicable for inorganic one-dimensional nanoparticle systems.Binary mixtures of 1D particles are rarely observed to cooperatively self-assemble into binary superlattices, as the particle types separate into phases. Here, the authors design a system that avoids phase separation, obtaining binary superlattices with different symmetries by simply tuning the particle diameter and mixture composition.

Increasing strength and conductivity of Cu alloy through abnormal plastic deformation of an intermetallic compound.

The precipitation strengthening of Cu alloys inevitably accompanies lowering of their electric conductivity and ductility. We produced bulk Cu alloys arrayed with nanofibers of stiff intermetallic compound through a precipitation mechanism using conventional casting and heat treatment processes. We then successfully elongated these arrays of nanofibers in the bulk Cu alloys to 400% of original length without breakage at room temperature using conventional rolling process. By inducing such an one-directional array of nanofibers of intermetallic compound from the uniform distribution of fine precipitates in the bulk Cu alloys, the trade-off between strength and conductivity and between strength and ductility could be significantly reduced. We observed a simultaneous increase in electrical conductivity by 1.3 times and also tensile strength by 1.3 times in this Cu alloy bulk compared to the conventional Cu alloys.

Green Synthesis of High-Purity Mesoporous Gold Sponges Using Self-Assembly of Gold Nanoparticles Induced by Thiolated Poly(ethylene glycol).

A facile and green synthesis method for mesoporous gold sponges has been developed, which involves a simple mixing of a very small amount of thiolated-poly(ethylene glycol) (SH-PEG) and citrate-covered gold nanoparticles (Au NPs) in aqueous solution at room temperature. While SH-PEG molecules have been widely used as biocompatible hydrophilic capping agents for Au NPs for stable dispersion in aqueous solution, here they are used as destabilizing agents. When SH-PEG molecules are mixed with citrate-covered Au NPs at the molar ratio ranging from 3 to 20 (SH-PEG/Au NP), mesoporous gold sponges with randomly interconnected 3D network structures are formed within 2 to 3 h. This is driven by the destabilization of negatively charged citrate molecules on Au NPs by a small number of SH-PEG molecules bonded on the particle surface, which results in the decrease in zeta potential and thus the assembly of Au NPs into porous sponges. The use of very low concentration of SH-PEG (ca. 20-200 nM) in aqueous solution at room temperature makes the method highly eco-friendly as well as results in high-purity as-synthesized gold sponges (98.7 wt %). The mesoporous gold sponges fabricated with the present method exhibit a high SERS activity, making them highly applicable for sensitive SERS detection of molecules.

Design of exceptionally strong and conductive Cu alloys beyond the conventional speculation via the interfacial energy-controlled dispersion of γ-Al2O3 nanoparticles.

The development of Cu-based alloys with high-mechanical properties (strength, ductility) and electrical conductivity plays a key role over a wide range of industrial applications. Successful design of the materials, however, has been rare due to the improvement of mutually exclusive properties as conventionally speculated. In this paper, we demonstrate that these contradictory material properties can be improved simultaneously if the interfacial energies of heterogeneous interfaces are carefully controlled. We uniformly disperse γ-Al2O3 nanoparticles over Cu matrix, and then we controlled atomic level morphology of the interface γ-Al2O3//Cu by adding Ti solutes. It is shown that the Ti dramatically drives the interfacial phase transformation from very irregular to homogeneous spherical morphologies resulting in substantial enhancement of the mechanical property of Cu matrix. Furthermore, the Ti removes impurities (O and Al) in the Cu matrix by forming oxides leading to recovery of the electrical conductivity of pure Cu. We validate experimental results using TEM and EDX combined with first-principles density functional theory (DFT) calculations, which all consistently poise that our materials are suitable for industrial applications.

Reliable and cost effective design of intermetallic Ni2Si nanowires and direct characterization of its mechanical properties.

We report that a single crystal Ni2Si nanowire (NW) of intermetallic compound can be reliably designed using simple three-step processes: casting a ternary Cu-Ni-Si alloy, nucleate and growth of Ni2Si NWs as embedded in the alloy matrix via designing discontinuous precipitation (DP) of Ni2Si nanoparticles and thermal aging, and finally chemical etching to decouple the Ni2Si NWs from the alloy matrix. By direct application of uniaxial tensile tests to the Ni2Si NW we characterize its mechanical properties, which were rarely reported in previous literatures. Using integrated studies of first principles density functional theory (DFT) calculations, high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDX) we accurately validate the experimental measurements. Our results indicate that our simple three-step method enables to design brittle Ni2Si NW with high tensile strength of 3.0 GPa and elastic modulus of 60.6 GPa. We propose that the systematic methodology pursued in this paper significantly contributes to opening innovative processes to design various kinds of low dimensional nanomaterials leading to advancement of frontiers in nanotechnology and related industry sectors.

Selective distributions of functionalized single-walled carbon nanotubes in a polymeric reverse hexagonal phase.

We have investigated the distributions of individually isolated and hydrophilically functionalized single-walled carbon nanotubes (p-SWNTs) in the Pluronic L121-water system at the reverse hexagonal phase using small-angle X-ray scattering (SAXS) and contrast-matched small-angle neutron scattering (SANS) measurements. As the p-SWNT-L121-water system is transitioned from the lamellar phase to the reverse hexagonal phase with temperature, p-SWNTs which were selectively distributed in the polar layers of the lamellar structure become selectively distributed in the cylindrical polar cores of the reverse hexagonal structure, forming a hexagonal array of p-SWNTs. This was clearly confirmed by the contrast-matched SANS measurements. The selective distribution of p-SWNTs in the reverse hexagonal phase is driven by the selective affinity of p-SWNTs to the polar domains of the block copolymer system. The method demonstrated in this study provides a new route for fabricating ordered SWNT superstructures and may be applicable for inorganic 1D nanoparticles such as semiconducting, metallic and magnetic nanorods which are of great interest.

Basilar plaque on high-resolution MRI predicts progressive motor deficits after pontine infarction.

BACKGROUND: The association between progressive motor deficits (PMD) in acute pontine infarction and basilar stenosis is unclear. High resolution MRI (HRMRI) is an emerging tool for basilar artery evaluation and might provide more accurate information. We aimed to analyze the association between basilar plaque assessed by HRMRI and PMD after acute pontine infarction. METHODS: We identified consecutive patients with unilateral pontine infarction within 24 h of stroke onset. All the patients underwent diffusion weighted MRI, MR angiography and HRMRI within 24 h of admission. PMD was defined as an increase in National Institutes of Health Stroke Scale score by ≥1 during hospitalization. Factors potentially associated with PMD were validated by multivariate analyses. RESULTS: Of a total of 87 patients, 63 (72%) had paramedian pontine infarction (PPI) and PMD was observed in 28 (32%) patients. Apparent basilar plaque assessed by HRMRI was more frequent in those with PMD than in those without PMD (52% versus 33%, p<0.001). In contrast, the frequency of basilar stenosis (>30%) assessed by MR angiography was similar regardless of PMD. In the patients with PPI, PMD was associated with hypertension and apparent plaque on HRMRI. After adjusting covariates, PMD was independently associated with apparent plaque on HRMRI (OR, 9.1; 95% CI 1.4-58.9). CONCLUSIONS: Our results suggest that basilar plaque assessed by HRMRI is associated with PMD in patients with acute unilateral pontine infarction. Since basilar stenosis may be underestimated by MR angiography, HRMRI may provide additional information for predicting PMD and evaluating basilar artery stenosis.

Highly ordered and highly aligned two-dimensional binary superlattice of a SWNT/cylindrical-micellar system.

We report a highly ordered intercalated hexagonal binary superlattice of hydrophilically functionalized single-walled carbon nanotubes (p-SWNTs) and surfactant (C12 E5 ) cylindrical micelles. When p-SWNTs (with a diameter slightly larger than that of the C12 E5 cylinders) were added to the hexagonally packed C12 E5 cylindrical-micellar system, p-SWNTs positioned themselves in such a way that the free-volume entropies for both p-SWNTs and C12 E5 cylinders were maximized, thus resulting in the intercalated hexagonal binary superlattice. In this binary superlattice, a hexagonal array of p-SWNTs is embedded in a honeycomb lattice of C12 E5 cylinders. The intercalated hexagonal binary superlattice can be highly aligned in one direction by an oscillatory shear field and remains aligned after the shear is removed.