The DESTINY+ Dust Analyser - a dust telescope for analysing cosmic dust dynamics and composition.

The DESTINY+(Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science) Dust Analyser (DDA) is a state-of-the-art dust telescope for the in situ analysis of cosmic dust particles. As the primary scientific payload of the DESTINY+ mission, it serves the purpose of characterizing the dust environment within the Earth-Moon system, investigating interplanetary and interstellar dust populations at 1 AU from the Sun and studying the dust cloud enveloping the asteroid (3200) Phaethon. DDA features a two-axis pointing platform for increasing the accessible fraction of the sky. The instrument combines a trajectory sensor with an impact ionization time-of-flight mass spectrometer, enabling the correlation of dynamical, physical and compositional properties for individual dust grains. For each dust measurement, a set of nine signals provides the surface charge, particle size, velocity vector, as well as the atomic, molecular and isotopic composition of the dust grain. With its capabilities, DDA is a key asset in advancing our understanding of the cosmic dust populations present along the orbit of DESTINY+. In addition to providing the scientific context, we are presenting an overview of the instrument's design and functionality, showing first laboratory measurements and giving insights into the observation planning. This article is part of a theme issue 'Dust in the Solar System and beyond'.

Use of accelerometry to detect varus thrust of osteoarthritic knees before and one year after high tibial osteotomy.

BACKGROUND: The purpose of this study was to determine the effects of high tibial osteotomy (HTO) on varus thrust during gait in patients with medial compartment knee osteoarthritis (KOA), and to identify factors that influence thrust before and one year after surgery. METHODS: HTO was performed in 60 KOA patients (70 knees, including 56 knees by open wedge and 14 by closed wedge). The control group comprised 28 normal, control subjects. Several parameters were evaluated before surgery and one year thereafter. Varus thrust was defined as acceleration of the thigh relative to the lower leg in the coronal plane. Knee-injury-and-osteoarthritis-outcome scores (KOOSs), knee joint angles, radiography, and mediolateral knee acceleration during free speed gait were measured and analyzed. RESULTS: One-year after HTO, KOOSs, knee extension angles, and range of knee motion were improved (p < 0.001). The hip-knee-ankle angle and joint-line-convergent angle (JLCA) had decreased (p < 0.001), and walking speed had increased (p < 0.001). Preoperatively, patient acceleration was significantly (p < 0.05) higher than that of controls, and it did not change after HTO. However, it was reduced significantly (p < 0.05) after adjusting for walking speed. Walking speed correlated significantly with acceleration preoperatively, postoperatively, and among controls. Surgical methods (open-wedge/closed-wedge HTO) and correction angle did not affect postoperative acceleration. There was a low correlation between acceleration and KOOSs (KOOSa, KOOSp), knee joint angles, or JLCA postoperatively, but no relationship was found between acceleration and these parameters in the preoperative or the control group. CONCLUSIONS: Walking speed correlated significantly with acceleration preoperatively, postoperatively, and with those of controls. Mediolateral acceleration of the thigh relative to the lower leg in patients with KOA was significantly higher than that of normal controls before surgery, and it did not change after HTO. However, after surgery it was reduced significantly after adjusting for walking speed.

Partial Stent-in-Stent Method with an Uncovered Self-Expandable Metallic Stent for Unresectable Malignant Hilar Bile Duct Obstruction.

(1) Background: There is controversy regarding stent placement for unresectable malignant hilar biliary obstruction (UMHBO). We mainly use the partial stent-in-stent (PSIS) method with an uncovered self-expandable metallic stent (UCSEMS) based on the drainage area and patency period. In this study, we investigated the usefulness and safety of the PSIS method. (2) Methods: In total, 59 patients who underwent the PSIS method for UMHBO at our hospital were included in the study. The technical success rate, clinical success rate, time to recurrent biliary obstruction (TRBO) and overall survival (OS) from the first placement, factors affecting TRBO and OS, and early complications within 30 days after the procedure were evaluated retrospectively. (3) Results: The technical and clinical success rates were 100% and 96.6%, respectively, with a TRBO of 121 days [95% confidence interval: 82-231] and an OS of 194 days [95% confidence interval: 113-305] after the first placement. Early complications occurred in nine patients (15.3%), including five cases of cholangitis, three cases of pancreatitis, and one case of cholecystitis. (4) Conclusions: The PSIS method for UMHBO is safe and useful with high technical and clinical success rates.

Nafion-Integrated Resorcinol-Formaldehyde Resin Photocatalysts for Solar Hydrogen Peroxide Production.

Photocatalytic generation of H2O2 from water and O2 is a promising strategy for liquid solar-fuel production. Previously reported powder photocatalysts promote a subsequent oxidative/reductive decomposition of the H2O2 generated, thereby producing low-H2O2-content solutions. This study reports that Nafion (Nf)-integrated resorcinol-formaldehyde (RF) semiconducting resin powders (RF@Nf), synthesized by polycondensation of resorcinol and formaldehyde with an Nf dispersion solution under high-temperature hydrothermal conditions, exhibit high photocatalytic activities and produce high-H2O2-content solutions. Nf acts as a surface stabilizer and suppresses the growth of RF resins. This generates small Nf-woven resin particles with large surface areas and efficiently catalyze water oxidation and O2 reduction. The Nf-woven resin surface, due to its hydrophobic nature, hinders the access of H2O2 and suppresses its subsequent decomposition. The simulated-sunlight irradiation of the resins in water under atmospheric pressure of O2 stably generates H2O2, producing high-H2O2-content solutions with more than 0.06 wt % H2O2 (16 mM).

Sunlight-Driven Generation of Hypochlorous Acid on Plasmonic Au/AgCl Catalysts in Aerated Chloride Solution.

HClO is typically manufactured from Cl2 gas generated by the electrochemical oxidation of Cl- using considerable electrical energy with a large concomitant emission of CO2. Therefore, renewable energy-driven HClO generation is desirable. In this study, we developed a strategy for stable HClO generation by sunlight irradiation of a plasmonic Au/AgCl photocatalyst in an aerated Cl- solution at ambient temperature. Plasmon-activated Au particles by visible light generate hot electrons, which are consumed by O2 reduction, and hot holes, which oxidize the lattice Cl- of AgCl adjacent to the Au particles. The formed Cl2 is disproportionated to afford HClO, and the removed lattice Cl- are compensated by the Cl- in the solution, thus promoting a catalytic HClO generation cycle. A solar-to-HClO conversion efficiency of ∼0.03% was achieved by simulated sunlight irradiation, where the resultant solution contained >38 ppm (>0.73 mM) of HClO and exhibited bactericidal and bleaching activities. The strategy based on the Cl- oxidation/compensation cycles will pave the way for sunlight-driven clean, sustainable HClO generation.

Polarity-Driven Isomerization of a Hydroxynaphthalimide-Containing Spiropyran at Room Temperature.

Design of spiropyrans showing spontaneous isomerization driven by the polarity of solvents is an important consideration for the synthesis of optical sensory materials. Although some spiropyrans undergo polarity-driven isomerization, they must be heated owing to the high activation energy required for isomerization. In this study, we describe that a spiropyran containing a hydroxynaphthalimide unit (1) exhibits a polarity-driven isomerization at room temperature. It exists as a colorless spirocyclic (SP) form in less polar solvents but is isomerized to a colored merocyanine (MC) form in polar solvents. The equilibrium amount of the MC form increases with an increase in the polarity of solvents. The MC form involves two resonance structures-the quinoidal and zwitterionic forms. In polar media, the zwitterionic form dominates mainly owing to solvation by polar molecules. Solvation stabilizes the negative charge of the zwitterionic form and decreases its ground state energy, thereby enhancing SP → MC isomerization. The SP ⇌ MC isomerization terminates within barely 30 s even at room temperature because the naphthol moiety with high π-electron density lowers the activation energy for the rate-determining rotational step.

Scalable Thermochromic Composite Based on a Ternary Polymer Blend for Temperature-Adaptive Solar Heat Management.

A scalable and durable thermochromic composite is developed for temperature-adaptive solar heat management using a carbon absorber and a thermoresponsive polymer blend consisting of an isolated polycaprolactone phase (PCL) and a continuous phase of miscible poly(methyl methacrylate) and polyvinylidene fluoride. The ternary blend exhibits reversible haze transition originating from the melting and crystallization of PCL. The refractive index matching between the molten PCL and surrounding miscible blend contributes to high-contrast haze switching in the range of 14-91% across the melting temperature of PCL (ca. 55 °C). The solar-absorption-switching properties of the composite are due to the spontaneous light-scattering switching in the polymer blend and the presence of a small amount of carbon black. Spectral measurements indicate that the solar reflectance of the composite sheet varies by 20% between 20 and 60 °C upon lamination with a Ag mirror. Solar heat management using the thermochromic composite is successfully demonstrated under natural sunlight, thereby realizing a temperature-adaptive thermal management system.

The predictive markers of severity and mortality in hospitalized hemodialysis patients with COVID-19 during Omicron epidemic.

INTRODUCTION: Predictive markers and prognosis remain unclear in hospitalized hemodialysis (HD) patients with coronavirus disease 2019 (COVID-19) during the Omicron epidemic. METHODS: We evaluated characteristics, laboratory parameters, and outcomes in hospitalized HD patients with COVID-19 (n = 102) at two centers between January and April 2022. RESULTS: The 30-day mortality rate was higher in moderate-critical group (n = 43) than mild group (n = 59) (16.3% vs. 1.7%; p = 0.007), and higher in patients with lower CC chemokine ligand 17 (CCL17) levels (<95.0 pg/mL) compared with normal CCL17 levels (19.0% versus 4.9%; p = 0.03). In multivariate analyses, a low CCL17 level (p = 0.003) was associated with moderate-critical conditions, and moderate-critical conditions (p = 0.04) were associated with 30-day mortality, whereas CCL17 was not associated with 30-day mortality. CONCLUSIONS: COVID-19 remains a fatal complication, and CCL17 was a predictive marker of severity in hospitalized HD patients during the Omicron epidemic.

Helicobacter pylori-negative Gastric Adenocarcinoma Mimicking Verrucous Gastritis in the Antrum: A Case Report and Literature Review.

A 46-year-old man was referred to our hospital for the examination of a flat elevated lesion with an erosion-like depression, located on the greater curvature of the antrum. Endoscopic submucosal dissection was performed. Histological findings of the resected specimen demonstrated a well-differentiated tubular adenocarcinoma with a diameter of 12 mm. No atrophy was observed in the tumor-adjacent mucosa. Serum Helicobacter pylori antibody estimation and 13C-urea breath tests yielded negative results. Immunohistochemical staining was positive for both gastric mucin and intestinal mucin. The final diagnosis was well-differentiated tubular adenocarcinoma with a gastrointestinal phenotype that originated in mucosa uninfected by H. pylori.

Photocatalytic Dinitrogen Fixation with Water on High-Phosphorus-Doped Carbon Nitride with Surface Nitrogen Vacancies.

Sunlight-driven photocatalytic dinitrogen (N2) fixation with water at ambient conditions is of vital importance for a sustainable energy society. The efficiency of this reaction, however, is still low because of the difficulty in promoting both water oxidation and N2 reduction reactions. Herein, we report that a high-phosphorus-doped carbon nitride with surface nitrogen vacancies (PCN(V)) synthesized by thermal condensation under a hydrogen (H2) atmosphere using phosphorus oxide (P2O5) as a phosphorus source efficiently promotes N2 fixation. The large numbers of the doped P atoms on the PCN(V)-P2O5 catalysts enhance the oxidation of water, while the N vacancies reduce N2, facilitating efficient ammonia (NH3) generation with an apparent quantum yield at 420 nm of 3.4%. Simulated sunlight illumination of the catalyst in water under N2 bubbling produces NH3 with a solar-to-chemical conversion efficiency of 0.16%, which is the highest efficiency among the previously reported powder photocatalysts.

Solar-Driven Generation of Hydrogen Peroxide on Phenol-Resorcinol-Formaldehyde Resin Photocatalysts.

Photocatalytic generation of H2O2 from water and O2 under sunlight is a promising artificial photosynthesis reaction to generate renewable fuel. We previously found that resorcinol-formaldehyde resin powders prepared with a high-temperature hydrothermal method become semiconductors comprising π-conjugated/π-stacked benzenoid-quinoid donor-acceptor resorcinol units and are active for photocatalytic H2O2 generation. Here, we have prepared phenol-resorcinol-formaldehyde resins with small amounts of phenol (∼5 mol % relative to resorcinol), which show enhanced photocatalytic activity. Incorporating phenol bearing a single -OH group in the resin matrices relaxes the restriction on the arrangement of the aromatic rings originating from the H-bonding interactions between the resorcinol -OH groups. This creates stronger donor-acceptor π-stacking and increases the electron conductivity of the resins. We have demonstrated that simulated sunlight illumination of the resins in water under an atmospheric pressure of O2 stably generated H2O2 with more than 0.9% solar-to-chemical conversion efficiency.

Polythiophene-Doped Resorcinol-Formaldehyde Resin Photocatalysts for Solar-to-Hydrogen Peroxide Energy Conversion.

The generation of hydrogen peroxide (H2O2) from water and dioxygen by sunlight-driven heterogeneous photocatalysis is a promising method for the artificial photosynthesis of a liquid solar fuel. We previously found that resorcinol-formaldehyde (RF) resin powders prepared by high-temperature hydrothermal synthesis act as highly active semiconductor photocatalysts for H2O2 generation. Herein, we report that RF resin powders doped with poly(3-hexylthiophene-2,5-diyl) (RF/P3HT) exhibit enhanced photocatalytic activities. The highly dispersed P3HT within the resin particles created charge transfer complexes with the conduction band of the resin via electron donation, facilitating efficient transfer of the photogenerated conduction band electrons through P3HT. This enhanced charge separation promoted efficient water oxidation and O2 reduction. The solar-to-chemical conversion efficiency for H2O2 generation on the RF/P3HT resin in water under simulated sunlight irradiation with atmospheric pressure of O2 was ∼1.0%, which is the highest efficiency reported for powder catalysts in artificial photosynthesis.

Spontaneous Isomerization of a Hydroxynaphthalene-Containing Spiropyran in Polar Solvents Enhanced by Hydrogen Bonding Interactions.

The synthesis of spiropyran dyes exhibiting solvent-driven isomerization even in the dark condition is an important subject for the design of optical materials. A conventional synthesis strategy involves the conjugation of indoline moieties with electron-deficient aromatic moieties. Herein, we report that a spiropyran conjugated with a hydroxynaphthalene moiety (1) is a new member exhibiting solvent-driven isomerization, even bearing an electron-donating -OH moiety. The dye exists as a colorless spirocyclic (SP) form in nonpolar media. It, however, shows a blue color in polar media, especially in aqueous media, due to the formation of ring-opened merocyanine (MC) forms, where the isomerization terminates in 10 s even at room temperature. The spontaneous SP → MC isomerization originates from the MC forms stabilized by the highly delocalized π-electrons on the hydroxynaphthalene moiety. The solvation in polar media and the hydrogen bonding interaction with water molecules decrease the ground-state energy of the MC forms, triggering spontaneous isomerization. The dye exhibits two MC absorption bands assigned to the trans-trans-cis (TTC) and cis-trans-cis (CTC) isomers. The absorbance of the CTC band increases more significantly with an increase in the water content, and the increase exhibits a linear relationship with a hydrogen-bond donor acidity of solvents. The phenolate oxygen of the CTC form has larger hydrogen-bond acceptor basicity, resulting in stronger stabilization by the water molecule.

Dynamic viscosity recovery of electrospinning solution for stabilizing elongated ultrafine polymer nanofiber by TEMPO-CNF.

Electrospinning is a widely used production method for nanoscale fine polymer fiber fabrics. An ultrafine fiber made of polymers such as polyvinylpyrrolidone (PVP) polyacrylic acid (PAA) has immense potential for applications in air filters, batteries, and biosensors. However, producing fabrics with long uniformly distributed ultrafine fibers of a mean diameter below ~ 200 nm is still a challenge, because such elongated-ultrafine fibers tend to break into beads before they reach the collector. Here, we exploits the thixotropy of the solution given by the addition of 2,2,6,6-tetramethylpiperidin-1-oxyl-oxidized cellulose nanofibers to recover the solution viscosity for stabilizing the electrostatically elongated nanofibers, whereby the solution is smooth in the syringe needle owing to the shear force but regain its original viscosity after being freed from electrostatic force. Using this method, we successfully fabricated a non-woven ultrafine-long nanofiber made of PVP and PAA with a mean diameter as low as ~ 90 nm with a negligible number of beads.

Photocatalytic hydrogen peroxide splitting on metal-free powders assisted by phosphoric acid as a stabilizer.

Hydrogen peroxide (H2O2) has received increasing attention as an energy carrier. To achieve a sustainable energy society, photocatalytic H2O2 splitting (H2O2 (l) → H2 (g) + O2 (g); ΔG° = + 131 kJ mol-1) is a desirable reaction for on-site H2 generation. However, this reaction has not been reported because conventional photocatalysis decomposes H2O2 by disproportionation (H2O2 (l) → H2O (l) + 1/2O2 (g); ΔG° = -117 kJ mol-1) and by promoting H2O2 reduction instead of H+ reduction. Here we report the successful example of H2O2 splitting. Visible light irradiation of a graphitic carbon nitride loaded with graphene quantum dots as co-catalysts (GQDs/g-C3N4) in a H2O2 solution containing phosphoric acid (H3PO4) produces H2. H3PO4 associates with H2O2 via hydrogen bonding, and this stabilization of H2O2 suppresses its reduction, thus promoting H+ reduction. The all-organic photosystem with H3PO4 as a stabilizer may provide a basis of photocatalytic H2O2 splitting.

Photocatalytic Dinitrogen Fixation with Water on Bismuth Oxychloride in Chloride Solutions for Solar-to-Chemical Energy Conversion.

Ammonia is an indispensable chemical. Photocatalytic NH3 production via dinitrogen fixation using water by sunlight illumination under ambient conditions is a promising strategy, although previously reported catalysts show insufficient activity. Herein, we showed that ultraviolet light irradiation of a semiconductor, bismuth oxychloride with surface oxygen vacancies (BiOCl-OVs), in water containing chloride anions (Cl-) under N2 flow efficiently produces NH3. The surface OVs behave as the N2 reduction sites by the photoformed conduction band electrons. The valence band holes are consumed by self-oxidation of interlayer Cl- on the catalyst. The hypochloric acid (HClO) formed absorbs ultraviolet light and undergoes photodecomposition into O2 and Cl-. These consecutive photoreactions produce NH3 with water as the electron donor. The Cl- in solution compensates for the removed interlayer Cl- and inhibits catalyst deactivation. Simulated sunlight illumination of the catalyst in seawater stably generates NH3 with 0.05% solar-to-chemical conversion efficiency, thus exhibiting significant potential of the seawater system for artificial photosynthesis.

Photocatalytic Dinitrogen Reduction with Water on Boron-Doped Carbon Nitride Loaded with Nickel Phosphide Particles.

Photocatalytic N2 reduction with water by sunlight irradiation is a challenging issue toward sustainable energy society, but previously reported photocatalysts had suffered from low stability and low activity. We prepared a boron-doped carbon nitride (BCN) semiconductor powder loaded with nickel phosphide particles (Ni2P) as cocatalysts. The Ni2P/BCN catalyst, when photoirradiated in pure water by simulated sunlight under N2 flow, successfully produces NH3 at room temperature. The B doping leads to a positive shift of the valence band level and enhances water oxidation by the photoformed holes. The Ni2P particles efficiently receive the conduction band electrons of BCN, leading to enhanced charge separation of the photoformed hole and electron pairs, and behave as N2 reduction sites. Simulated sunlight irradiation of the catalyst in water stably generates NH3 with 0.010% solar-to-chemical conversion efficiency. This noble-metal-free system therefore shows a significant potential for N2 photofixation.

Multifaceted property tailoring of polyamide 6 by blending miscible and immiscible components: ternary blends of polyamide 6/polyethylene terephthalate/phenol novolac.

Ternary polymer blends comprising miscible and immiscible components are examined to improve the mechanical properties of polyamide 6 (PA6) under humid and high-temperature conditions. Miscible polymers increase the glass transition temperature (T g), owing to their strong inter-molecular interactions, while phase-separated immiscible polymers reinforce the physical properties of PA6 as filler materials. Ternary blends exhibit these combined miscible and immiscible component contributions. Thus, in this study, ternary blends comprising PA6, polyethylene terephthalate (PET, immiscible component), and phenol novolac (PN, miscible component) are prepared by melt mixing. The PA6 stiffness in the water-absorbed state is reinforced by PET. Moreover, the proposed PA6/PET/PN ternary blends exhibit higher T g values and lower water absorption rates than those of the PA6/PET binary blend, owing to the PN contribution. The PET and PN contributions are achieved independently and can be controlled via the composition ratios of the component polymers. Multifaceted property tailoring is thus demonstrated.

Solar-to-hydrogen peroxide energy conversion on resorcinol-formaldehyde resin photocatalysts prepared by acid-catalysed polycondensation.

The photocatalytic generation of hydrogen peroxide from water and dioxygen (H2O + 1/2O2 → H2O2, ΔG° = +117 kJ mol-1) under sunlight is a promising strategy for the artificial photosynthesis of a liquid fuel. We had previously found that resorcinol-formaldehyde (RF) resin powders prepared by the base-catalysed high-temperature hydrothermal method act as semiconductor photocatalysts for H2O2 generation. Herein, we report that RF resins prepared by the acid-catalysed high-temperature hydrothermal method (~523 K) using common acids at pH < 4 exhibit enhanced photocatalytic activity. The base- and acid-catalysed methods both produce methylene- and methine-bridged resins consisting of π-conjugated and π-stacked benzenoid-quinoid donor-acceptor resorcinol units. The acidic conditions result in the resins with a lower bandgap (1.7 eV) and higher conductivity because the lower-degree of crosslinking creates a strongly π-stacked architecture. The irradiation of the RF-acid resins with simulated sunlight in water with atmospheric-pressure O2 generates H2O2 at a solar-to-chemical conversion efficiency of 0.7%, which is the highest efficiency ever reported for powder catalysts used in artificial photosynthesis.

Relationship of Inflammatory Cytokines From M1-Type Microglia/Macrophages at the Injured Site and Lumbar Enlargement With Neuropathic Pain After Spinal Cord Injury in the CCL21 Knockout (plt) Mouse.

Spinal cord injury (SCI) causes loss of normal sensation and often leads to debilitating neuropathic pain (NeP). Chronic NeP develops at or below the SCI lesion in as many as 80% of patients with SCI and may be induced by modulators of neuronal excitability released from activated microglia and macrophages. In the inflammatory response after SCI, different microglia/macrophage populations that are classically activated (M1 phenotype) or alternatively activated (M2 phenotype) have become of great interest. Chemokines have also recently attracted attention in neuron-microglia communication. CCL21 is a chemokine that activates microglia in the central nervous system (CNS) and is expressed only in neurons with an insult or mechanical injury. In this study using an SCI model in mutant (plt) mice with deficient CCL21 expression, we assessed post-SCI NeP and expression of microglia/macrophages and inflammatory cytokines at the injured site and lumbar enlargement. SCI-induced hypersensitivities to mechanical and thermal stimulation were relieved in plt mice compared with those in wild-type (C57BL/6) mice, although there was no difference in motor function. Immunohistochemistry and flow cytometry analysis showed that the phenotype of microglia/macrophages was M1 type-dominant in both types of mice at the lesion site and lumbar enlargement. A decrease of M1-type microglia/macrophages was seen in plt mice compared with wild-type, while the number of M2-type microglia/macrophages did not differ between these mice. In immunoblot analysis, expression of M1-induced cytokines [tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ)] was decreased in plt mice, while that of M2-induced cytokines interleukin-4 (IL-4, IL-10) did not differ in the two types of mice. The results of this study indicate that suppression of expression of inflammatory cytokines by decreasing the number of M1-type microglia/macrophages at the injured site and lumbar enlargement is associated with provision of an environment for reduction of NeP. These findings may be useful for the design of new therapies to alleviate NeP after SCI.