One-pot synthesis of Ag-In-Ga-S nanocrystals embedded in a Ga2O3 matrix and enhancement of band-edge emission by Na+ doping.

I-III-VI-based semiconductor quantum dots (QDs) have been intensively explored because of their unique controllable optoelectronic properties. Here we report one-pot synthesis of Na-doped Ag-In-Ga-S (AIGS) QDs incorporated in a Ga2O3 matrix. The obtained QDs showed a sharp band-edge photoluminescence peak at 557 nm without a broad-defect site emission. The PL quantum yield (QY) of such QDs was 58%, being much higher than that of AIGS QDs without Na+ doping, 29%. The obtained Na-doped AIGS/Ga2O3 composite particles were used as an emitting layer of green QD light-emitted diodes. A sharp electroluminescence (EL) peak was observed at 563 nm, being similar to that in the PL spectrum of the QDs used. The external quantum efficiency of the device was 0.6%.

Visualization of airborne droplets generated with dental handpieces and verification of the efficacy of high-volume evacuators: an in vitro study.

BACKGROUND: The COVID-19 pandemic led to concerns about the potential airborne transmission of the virus during dental procedures, but evidence of actual transmission in clinical settings was lacking. This study aimed to observe the behavior of dental sprays generated from dental rotary handpieces and to evaluate the effectiveness of high-volume evacuators (HVEs) using laser light sheets and water-sensitive papers. METHODS: A dental manikin and jaw model were mounted in a dental treatment unit. Mock cutting procedures were performed on an artificial tooth on the maxillary left central incisor using an air turbine, a contra-angle electric micromotor (EM), and a 1:5 speed-up contra-angle EM (×5EM). Intraoral vacuum and extraoral vacuum (EOV) were used to verify the effectiveness of the HVEs. The dynamics and dispersal range of the dental sprays were visualized using a laser light sheet. In addition, environmental surface pollution was monitored three-dimensionally using water-sensitive papers. RESULTS: Although the HVEs were effective in both the tests, the use of EOV alone increased vertical dispersal and pollution. CONCLUSIONS: The use of various types of HVEs to reduce the exposure of operators and assistants to dental sprays when using dental rotary cutting instruments is beneficial. The study findings will be helpful in the event of a future pandemic caused by an emerging or re-emerging infectious disease.

Development of Cu-In-Ga-S quantum dots with a narrow emission peak for red electroluminescence.

Narrowing the emission peak width and adjusting the peak position play a key role in the chromaticity and color accuracy of display devices with the use of quantum dot light-emitting diodes (QD-LEDs). In this study, we developed multinary Cu-In-Ga-S (CIGS) QDs showing a narrow photoluminescence (PL) peak by controlling the Cu fraction, i.e., Cu/(In+Ga), and the ratio of In to Ga composing the QDs. The energy gap of CIGS QDs was enlarged from 1.74 to 2.77 eV with a decrease in the In/(In+Ga) ratio from 1.0 to 0. The PL intensity was remarkably dependent on the Cu fraction, and the PL peak width was dependent on the In/(In+Ga) ratio. The sharpest PL peak at 668 nm with a full width at half maximum (fwhm) of 0.23 eV was obtained for CIGS QDs prepared with ratios of Cu/(In+Ga) = 0.3 and In/(In+Ga) = 0.7, being much narrower than those previously reported with CIGS QDs, fwhm of >0.4 eV. The PL quantum yield of CIGS QDs, 8.3%, was increased to 27% and 46% without a PL peak broadening by surface coating with GaSx and Ga-Zn-S shells, respectively. Considering a large Stokes shift of >0.5 eV and the predominant PL decay component of ∼200-400 ns, the narrow PL peak was assignable to the emission from intragap states. QD-LEDs fabricated with CIGS QDs surface-coated with GaSx shells showed a red color with a narrow emission peak at 688 nm with a fwhm of 0.24 eV.

Tensile strength of nanocrystalline FeCoNi medium-entropy alloy fabricated using electrodeposition.

Crystal-grain refinement is one of the effective approaches to obtaining high-strength materials. A good strength/ductility balance has been reported in fine grains of high- and medium-entropy alloys. However, crystal-grain refinement at the nanometer scale has not been achieved yet. In this study, we used electrodeposition to fabricate 0.2-mm thick equiatomic FeCoNi medium-entropy alloys (MEAs) with 10-nm crystal grains. The nanocrystalline FeCoNi MEAs exhibit the maximum tensile strength of 1.6 GPa, which is the highest reported result to date.

Effect of electron beam irradiation in gas atmosphere during ETEM.

Transmission electron microscopy (TEM) is used to observe the atomic structures of materials. Environmental TEM (ETEM) is a method wherein a gas can be evaluated and it has been used to observe the dynamic reaction between materials and gases at the atomic level. An electron beam (EB), which has a sufficiently high energy (exceeding a few tens of kilovolts), can be used to ionize gas molecules. Subsequently, the ionized molecules might react with the materials during ETEM. Therefore, the current generated by the ions and electrons were measured to verify the presence of ions generated due to the ionization of the N2 gas atmosphere during EB irradiation in ETEM. The electron energy loss spectra (EELS) were acquired from the N2 gas atmosphere to estimate the types of ions generated. The results demonstrated that ions and electrons were generated in the N2 atmosphere during ETEM and EB irradiation. Moreover, the EELS analysis indicated that the generated ion was N2+. The material observation conducted using gas ETEM can detect the reaction between gases, ions, and materials.

Microstructural heterogeneity in the electrodeposited Ni: insights from growth modes.

Microstructures of electrodeposited Ni were studied from the perspective of growth modes during electrodeposition. The electrodeposited Ni had a heterogeneous microstructure composed of nanocrystalline- and microcrystalline-grains. Electron backscatter diffraction analyses showed that nanocrystalline- and microcrystalline-grains were preferentially oriented to specific planes. Secondary ion mass spectrometry also revealed that coarse-grained regions had higher S content than that of finer-grained regions. Hence, microstructural heterogeneity in electrodeposited Ni is reflected by the overlap of inhibited and free growth modes. Our discussion surrounding microstructural heterogeneity also provides insight into other electrodeposited nanocrystalline systems.

Controlling the oxidation state of molybdenum oxide nanoparticles prepared by ionic liquid/metal sputtering to enhance plasmon-induced charge separation.

Nanoparticles composed of molybdenum oxide, MoO x , were successfully prepared by room-temperature ionic liquid (RTIL)/metal sputtering followed by heat treatment. Hydroxyl groups in RTIL molecules retarded the coalescence between MoO x NPs during heat treatment at 473 K in air, while the oxidation state of Mo species in MoO x nanoparticles (NPs) could be modified by changing the heat treatment time. An LSPR peak was observed at 840 nm in the near-IR region for MoO x NPs of 55 nm or larger in size that were annealed in a hydroxyl-functionalized RTIL. Photoexcitation of the LSPR peak of MoO x NPs induced electron transfer from NPs to ITO electrodes.

[Challenges Faced by the Palliative Care Team in Treating Breast Cancer Outpatients with Chemotherapy].

In this study, we examined 239 outpatients receiving chemotherapy for breast cancer for a period of 6 months from July 2016 to December 2016. Using a questionnaire, we investigated the patients' symptom score and uneasiness. A symptom score of 2 and over was found in 24.7%(59)of the cases. Twenty-seven of the 59 cases experienced adverse effects of chemotherapy. Peripheral neuropathy was observed in 20 cases, of which only 2 cases improved after providing palliative care. Palliative care was effective against nausea, constipation, malaise, and sleeping disorders. Thirty-two cases(13.4%)had 5 or more painful feeling score. Among these, 10 cases resulted from the adverse effects of treatment, 10 cases from the aggravation of existing cancer, and 6 cases showed anxiety for the illness, family, and future. In 15 of the 32 cases, the pain score improved by providing palliative care, conversation with the nursing staff, reduction in the quantity of drug intake, etc.

Core Nanoparticle Engineering for Narrower and More Intense Band-Edge Emission from AgInS2/GaSx Core/Shell Quantum Dots.

Highly luminescent silver indium sulfide (AgInS2) nanoparticles were synthesized by dropwise injection of a sulfur precursor solution into a cationic metal precursor solution. The two-step reaction including the formation of silver sulfide (Ag2S) nanoparticles as an intermediate and their conversion to AgInS2 nanoparticles, occurred during the dropwise injection. The crystal structure of the AgInS2 nanoparticles differed according to the temperature of the metal precursor solution. Specifically, the tetragonal crystal phase was obtained at 140 °C, and the orthorhombic crystal phase was obtained at 180 °C. Furthermore, when the AgInS2 nanoparticles were coated with a gallium sulfide (GaSx) shell, the nanoparticles with both crystal phases emitted a spectrally narrow luminescence, which originated from the band-edge transition of AgInS2. Tetragonal AgInS2 exhibited narrower band-edge emission (full width at half maximum, FWHM = 32.2 nm) and higher photoluminescence (PL) quantum yield (QY) (49.2%) than those of the orthorhombic AgInS2 nanoparticles (FWHM = 37.8 nm, QY = 33.3%). Additional surface passivation by alkylphosphine resulted in higher PL QY (72.3%) with a narrow spectral shape.

Fluorescent Tau-derived Peptide for Monitoring Microtubules in Living Cells.

Microtubules (MTs) are key cytoskeletal components that modulate various cellular activities with their dynamic structural changes, including polymerization and depolymerization. To monitor the dynamics of MTs in living cells, many drug-based fluorescent probes have been developed; however, these also potentially disturb the polymerization/depolymerization of MTs. Here, we report nondrug, peptide-based fluorescent probes to monitor MTs in living cells. We employed a Tau-derived peptide (TP) that has been shown to bind MTs without inhibiting polymerization/depolymerization in vitro. We show that a tetramethylrhodamine (TMR)-labeled TP (TP-TMR) is internalized into HepG2 cells and binds to intracellular MTs, enabling visualization of MTs as clear, fibrous structures. The binding of TP-TMR shows no apparent effects on polymerization/depolymerization of MTs induced by MT-targeted drugs and temperature change. The main uptake mechanism of TP-TMR was elucidated as endocytosis, and partial endosomal escape resulted in the binding of TP-TMR to MTs. TP-TMR exhibited no cytotoxicity compared with MT-targeted drug scaffolds. These results indicate that TP scaffolds can be exploited as useful MT-targeted tools in living cells, such as in long-term imaging of MTs.

Stabilization of microtubules by encapsulation of the GFP using a Tau-derived peptide.

We constructed GFP-encapsulated microtubules (MTs) using a Tau-derived peptide which binds to their interior. The encapsulation of the GFP dramatically increased the rigidity of MTs, resulting in their enhanced velocity on a kinesin-coated substrate. Moreover, the GFP-encapsulated MTs were significantly more stable than normal MTs.

Wavelength-Tunable Band-Edge Photoluminescence of Nonstoichiometric Ag-In-S Nanoparticles via Ga3+ Doping.

The nonstoichiometry of I-III-VI semiconductor nanoparticles, especially the ratio of group I to group III elements, has been utilized to control their physicochemical properties. We report the solution-phase synthesis of nonstoichiometric Ag-In-S and Ag-In-Ga-S nanoparticles and results of the investigation of their photoluminescence (PL) properties in relation to their chemical compositions. While stoichiometric AgInS2 nanoparticles simply exhibited only a broad PL band originating from defect sites in the particles, a narrow band edge PL peak newly appeared with a decrease in the Ag fraction in the nonstoichiometric Ag-In-S nanoparticles. The relative PL intensity of this band edge emission with respect to the defect-site emission was optimal at a Ag/(Ag + In) value of ca. 0.4. The peak wavelength of the band edge emission was tunable from 610 to 500 nm by increased doping with Ga3+ into Ag-In-S nanoparticles due to an increase of the energy gap. Furthermore, surface coating of Ga3+-doped Ag-In-S nanoparticles, that is, Ag-In-Ga-S nanoparticles, with a GaS x shell drastically and selectively suppressed the broad defect-site PL peak and, at the same time, led to an increase in the PL quantum yield (QY) of the band edge emission peak. The optimal PL QY was 28% for Ag-In-Ga-S@GaS x core-shell particles, with green band-edge emission at 530 nm and a full width at half-maximum of 181 meV (41 nm). The observed wavelength tunability of the band-edge PL peak will facilitate possible use of these toxic-element-free I-III-VI-based nanoparticles in a wide area of applications.

HFA-BDP Metered-Dose Inhaler Exhaled Through the Nose Improves Eosinophilic Chronic Rhinosinusitis With Bronchial Asthma: A Blinded, Placebo-Controlled Study.

Background: Eosinophilic chronic rhinosinusitis (ECRS) is a subtype of chronic rhinosinusitis with nasal polyps in Japanese. ECRS highly associated with asthma is a refractory eosinophilic airway inflammation and requires comprehensive care as part of the united airway concept. We recently reported a series of ECRS patients with asthma treated with fine-particle inhaled corticosteroid (ICS) exhalation through the nose (ETN). Objective: To evaluate fine-particle ICS ETN treatment as a potential therapeutic option in ECRS with asthma. Methods: Twenty-three patients with severe ECRS under refractory to intranasal corticosteroid treatment were randomized in a double-blind fashion to receive either HFA-134a-beclomethasone dipropionate (HFA-BDP) metered-dose inhaler (MDI) ETN (n = 11) or placebo MDI ETN (n = 12) for 4 weeks. Changes in nasal polyp score, computed tomographic (CT) score, smell test, and quality of life (QOL) score from baseline were assessed. Fractionated exhaled nitric oxide (FENO) was measured as a marker of eosinophilic airway inflammation. Response to corticosteroids was evaluated before and after treatment. Additionally, deposition of fine-particles was visualized using a particle deposition model. To examine the role of eosinophils on airway inflammation, BEAS-2B human bronchial epithelial cells were co-incubated with purified eosinophils to determine corticosteroid sensitivity. Results: HFA-BDP MDI ETN treatment improved all assessed clinical endpoints and corticosteroid sensitivity without any deterioration in pulmonary function. FENO and blood eosinophil number were reduced by HFA-BDP MDI ETN treatment. The visualization study suggested that ETN at expiratory flow rates of 10-30 L/min led to fine particle deposition in the middle meatus, including the sinus ostia. Co-incubation of eosinophils with BEAS-2B cells induced corticosteroid resistance. Conclusions: Additional HFA-BDP MDI ETN treatment was beneficial in patients with ECRS and should be considered as a potential therapeutic option for eosinophilic airway inflammation such as ECRS with asthma. (UMIN-CTR: R000019325) (http://www.umin.ac.jp/ctr/index.htm).

Molecular Encapsulation Inside Microtubules Based on Tau-Derived Peptides.

Microtubules are cytoskeletal filaments that serve as attractive scaffolds for developing nanomaterials and nanodevices because of their unique structural properties. The functionalization of the outer surface of microtubules has been established for this purpose. However, no attempts have been made to encapsulate molecules inside microtubules with 15 nm inner diameter. The encapsulation of various molecular cargos inside microtubules constitutes a new concept for nanodevice and nanocarrier applications of microtubules. Here, we developed peptide motifs for binding to the inner surface of microtubules, based on a repeat domain of the microtubule-associated protein Tau. One of the four Tau-derived peptides, 2N , binds to a taxol binding pocket of ß-tubulin located inside microtubules by preincubation with tubulin dimer and subsequent polymerization of the peptide-tubulin complex. By conjugation of 2N to gold nanoparticles, encapsulation of gold nanoparticles inside microtubules was achieved. The methodology for molecular encapsulation inside microtubules by the Tau-derived peptide is expected to advance the development of microtubule-based nanomaterials and nanodevices.

Rapid Sintering of Li2O-Nb2O5-TiO2 Solid Solution by Air Pressure Control and Clarification of Its Mechanism.

We first successfully synthesized Li1+x−yNb1−x−3yTix+4yO3 (LNT) solid solutions (0.13 ≤ x ≤ 0.18, 0 ≤ y ≤ 0.06) rapidly at 1373 K for one hour under 0.35 MPa by the controlling of air pressure using an air-pressure control atmosphere furnace. The composition is a formation area of a superstructure for LNT, in which the periodical intergrowth layer was formed in the matrix, and where it can be controlled by Ti content. Therefore, the sintering time depended on Ti content, and annealing was repeated for over 24 h until a homogeneous structure was formed using a conventional electric furnace. We clarified the mechanism of the rapid sintering using various microscale to nanoscale characterization techniques: X-ray diffraction, a scanning electron microscope, a transmission electron microscope (TEM), a Cs-corrected scanning TEM equipped with electron energy-loss spectroscopy, and X-ray absorption fine structure spectroscopy.

Influence of the location of nasal polyps on olfactory airflow and olfaction.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) often results in decreased olfaction. In this study, we examined the relationship between nasal polyp location and olfactory airflow and odorant transport changes using virtual nasal polyp models at different locations and computational fluid dynamics (CFD) analysis. We also compared olfactory airflow and olfaction between patients with nasal polyps at different locations using CFD analysis and an olfactory test. METHODS: Nasal computed tomography images were used to generate a normal model and 4 virtual nasal polyp models based on polyp locations, including the olfactory region (all-olfactory model), the region anterior to the olfactory region (preolfactory model), the middle meatus (middle-meatus model), and the superior meatus (superior-meatus model). Various airflow parameters were compared between these models and a normal model without polyps. We then performed a similar comparison between the 3-dimensional (3D) reconstruction models of patients with nasal polyps, and retrospectively investigated the correlation between olfaction and nasal polyp location in those patients. RESULTS: Virtual nasal polyp analysis revealed dispersion of olfactory airflow in the all-olfactory model. Olfactory airflow and odorant transport showed maximum decrease in the preolfactory model and a slight decrease in the superior-meatus model. Olfactory airflow by polyps was further decreased by blockade of the olfactory airflow inlet than of the outlet. The findings obtained by patients corresponded well to those of the virtual polyp analysis. CONCLUSION: Olfactory airflow and olfaction are differentially affected by nasal polyp location. This finding is important for planning polyp-removal surgeries from the perspective of improving patient olfaction.

Mechanisms Underlying Improvement in Obstructive Sleep Apnea Syndrome by Uvulopalatopharyngoplasty.

In a previous case report, we determined for the first time that uvulopalatopharyngoplasty (UPPP) does not change the volume of the upper airway but causes morphological changes in the entire upper airway. The objective of this study is to elucidate the mechanisms underlying the improvement in obstructive sleep apnea syndrome (OSAS) by UPPP. We present an additional case involving a patient with OSAS treated using UPPP. Morphological and numerical parameter changes after surgery were compared with the corresponding preoperative values. Anatomically accurate upper airway computational models were reconstructed from computed tomographic imaging data. In addition, computed fluid dynamics analysis was performed to reveal inhalation flow characteristics before and after UPPP and clearly assess the effect of UPPP on airflow patterns in the patient's upper airway. An important benefit of UPPP is the morphological changes in the entire upper airway, in addition to widening the restricted area. These morphological changes induce laminarization of the pharyngeal jet. To obtain sufficient efficacy of UPPP in OSAS, the morphological changes in the upper airway and the airflow pattern after the surgery must be controlled.

Replacement of SFC-DPI with SFC-MDI exhaled through the nose improves eosinophilic chronic rhinosinusitis in patients with bronchial asthma.

OBJECTIVE: Eosinophilic chronic rhinosinusitis (ECRS), a subgroup of chronic rhinosinusitis with nasal polyps, is a refractory disease closely associated with bronchial asthma. We recently reported on the efficacy of ultra-fine particle inhaled corticosteroids (ICS) (hydrofluoroalkane-134a-beclomethasone dipropionate: HFA-BDP) exhalation through the nose (ETN) treatment for mild-to-moderate asthmatics with ECRS. However, the effect of HFA-BDP ETN was found to be transient in some cases with severe ECRS and asthma, requiring treatment with higher-dose ICS and long-acting ß2-agonists (LABA). Here, we present a case of refractory ECRS with severe asthma treated with a combination of high-dose ICS and LABA ETN, and we discuss the mechanisms for its effectiveness. METHODS: A 57-year-old man was treated with the combined regimen of HFA-BDP ETN and salmeterol/fluticasone combination (SFC) dry powder inhaler (DPI) for his refractory ECRS with severe asthma. For better control, we replaced SFC-DPI with SFC metered-dose inhaler (MDI) ETN and evaluated the clinical effect and corticosteroid sensitivity. We also examined the flow and deposition of fine particles released by SFC-MDI ETN. RESULTS: After switching to SFC-MDI ETN, the patient's conditions markedly resolved with the restoration of corticosteroid sensitivity and PP2A activity. The fine particles released by SFC-MDI ETN at least partially flowed out through the external nares and seemed to be deposited on the ethmoid sinus. CONCLUSION: Fine particle ICS/LABA ETN might be an additional therapeutic option for refractory ECRS with severe asthma and corticosteroid insensitivity.
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Single-step preparation of indium tin oxide nanocrystals dispersed in ionic liquids via oxidation of molten In-Sn alloys.

Oxidation of molten In-Sn alloys was carried out in ionic liquids by heat treatment with vigorous stirring, resulting in the formation of indium tin oxide (ITO) nanocrystals. The ITO nanocrystals exhibited a plasmon peak, the peak wavelength of which was blue-shifted with an increase in the Sn fraction in ITO.

Photoelectrochemical water splitting enhanced by self-assembled metal nanopillars embedded in an oxide semiconductor photoelectrode.

Production of chemical fuels by direct solar energy conversion in a photoelectrochemical cell is of great practical interest for developing a sustainable energy system. Various nanoscale designs such as nanowires, nanotubes, heterostructures and nanocomposites have been explored to increase the energy conversion efficiency of photoelectrochemical water splitting. Here we demonstrate a self-organized nanocomposite material concept for enhancing the efficiency of photocarrier separation and electrochemical energy conversion. Mechanically robust photoelectrodes are formed by embedding self-assembled metal nanopillars in a semiconductor thin film, forming tubular Schottky junctions around each pillar. The photocarrier transport efficiency is strongly enhanced in the Schottky space charge regions while the pillars provide an efficient charge extraction path. Ir-doped SrTiO3 with embedded iridium metal nanopillars shows good operational stability in a water oxidation reaction and achieves over 80% utilization of photogenerated carriers under visible light in the 400- to 600-nm wavelength range.