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The combination of metasurface with optical emitters provides a unique opportunity to control the emission. The metasurface effect strongly depends on the spectral overlap between the internal electronic transitions of the emitter and the optical resonances of the metasurface. Elaborate design of the metasurface could realize the resonances at both absorption and emission wavelengths of the emitter, but it usually leads to complexity in fabrication. In this work, we propose a very simple strategy to obtain the resonances at both wavelengths by sandwiching the emitter layer with a pair of metasurfaces designed for absorption and emission, respectively. For this purpose, we use a sticker of Al metasurface, which is the array of Al nanoparticles embedded in a flexible polymer film that can be stuck on any clean surfaces. The metasurface stack is prepared by simply placing the sticker, resonating at the emission wavelength, on the emitter layer deposited on the TiO 2 metasurface resonating at the absorption wavelength. The overall enhancement achieved for the stack of the metasurfaces can be understood roughly as the multiplication of contributions from the respective metasurfaces. Employing a sticker provides an easy-to-make way of constructing a stack of metasurfaces, which increases the degree of freedom in designing the metasurface-coupled emitters. [ABSTRACT FROM AUTHOR]

Although titanium dioxide ( TiO 2) is a promising constituent of the metasurface operative in the visible, the experimental demonstration is limited so far because TiO 2 is intrinsically chemically/physically stable and is hard to be processed into nanostructures with high precision. In this paper, we develop a facile pathway to fabricate the TiO 2 metasurface via oxidation of Ti nanoparticle array that can be made by the conventional lift-off process. Under an optimized heat-treatment procedure in air, Ti nanoparticles are converted to TiO 2 nanoparticles with a size expansion predictable by the molar volume mismatch between Ti and TiO 2 , while the global periodic arrangement is retained. We apply this technique to a Ti nanoparticle array fabricated on the phosphor plate of yttrium aluminum garnet doped with Ce 3 + (YAG:Ce) and demonstrate the directional outcoupling of emission through the metasurface. The photoluminescence from the YAG:Ce plate is directionally enhanced in the forward direction, as large as three times as much compared to that from the flat YAG:Ce plate without the metasurface. Because of the high transparency and lossless feature of TiO 2 in the visible, the present metasurface does not lower the total quantum yield of the system consisting of the YAG:Ce plate and the TiO 2 metasurface, which is beneficial for the solid-state-lighting application. [ABSTRACT FROM AUTHOR]

Also related to nonlinear processes, Yang I et al. i outline in another Perspective the state of the art of rare-earth-doped upconversion (UC) nano- and microparticles.[18] Specifically, authors provide the main keys that determine the luminescence efficiency of single UC systems. Our key physiological functions and economic activity depend on the constant driving force of light.[1] Over the last few decades, incandescent and fluorescent lamps have been surpassed by electroluminescent semiconductors, giving birth to a new technology, so-called Solid State Lighting (SSL). [Extracted from the article]

White light-emitting diodes (LEDs), light sources that combine blue LEDs and yellow phosphors, are equipped with bulky optics such as lenses, mirrors, and/or reflectors to shape the light into the required directions. The presence of bulky optics causes optical loss and limits the design. Here, a periodic array of metallic nanocylinders, which exhibits a high scattering efficiency owing to the excitation of localized surface plasmon resonance, is proposed as an alternative means of achieving a directional output without the limitations of bulky optics. A prototype of a directional light emitter is fabricated consisting of an Al nanocylinder array on a yellow phosphor plate and a blue laser. The array shapes the yellow luminescence into the forward direction and generates directional quasi-white light (correlated color temperature of 4900 K). The intensity enhancement reaches a factor of five in the forward direction and is further improved up to a factor of seven by the deposition of a multilayer dichroic mirror on the back side of the phosphor plate, resulting in conversion efficiencies as high as 90 lm/W. Our results pave the way toward the development of efficient and compact directional white-light-source devices without any bulky optics. [ABSTRACT FROM AUTHOR]

Various optical phenomena can be induced in periodic arrays of nanoparticles by the radiative coupling of the local dipoles in each particle. Probably the most impressive example is bound states in the continuum (BICs), which are electromagnetic modes with a dispersion inside the light cone but infinite lifetime, that is, modes that cannot leak to the continuum. Symmetry‐protected BICs appear at highly symmetric points in the dispersion of periodic systems. Although the addition of nonequivalent lattice points in a unit cell is an easy and straightforward way of tuning the symmetry, BICs in such particle lattice, that is, non‐Bravais lattice, are less explored among periodic systems. Starting from a periodic square lattice of Si nanodisks, three non‐Bravais lattices are prepared by detuning size and position of the second disk in the unit cell. Diffraction‐induced coupling excites magnetic/electric dipoles in each nanodisk, producing two surface lattice resonances at the Γ point with a band gap in between. The high/low energy branch becomes a BIC for the size/position‐detuned array, respectively, while both branches are bright (or leaky) when both size and position are detuned simultaneously. The unexplored role of the interplay between magnetic and electric dipoles in dielectric nanoparticles in connection with the change of BIC to bright character in the detuned arrays is discussed with the aid of a coupled electric and magnetic dipole model. This study gives a simple way of tuning BICs at telecom wavelengths in non‐Bravais lattices, including both plasmonic and dielectric systems, thus scalable to a wide range of frequencies. [ABSTRACT FROM AUTHOR]

For the fiber‐based magneto‐optical (MO) devices, like Faraday optical isolator, the target MO glasses are supposed to strike a balance among the following properties: high Verdet constant, chemical and physical stabilities, compatibility with the fiber drawing process, and the connectivity to the silica glass fiber networks. In this work, we report on the MO application of Tb2O3‐Al2O3‐SiO2‐B2O3 (TASB) glasses as a derivative of the yttrium aluminum silicate (YAS) glass fiber systems which have been intensively studied for their huge potential in the context of all‐fiber lasers. We found that MO properties of the obtained TASB glasses vary systematically with the B2O3 contents. The effects of B2O3 on the local glass structures and the valence state of Tb ions were clarified via nuclear magnetic resonance, electron spin resonance, X‐ray photoemission spectroscopy, and Raman spectroscopy. B2O3 content in TASB glasses leads to a certain degree of depolymerization in glass network and most of Tb4+ ions from the raw material of Tb4O7 are reduced to Tb3+ ions even in air, resulting in an improved MO properties. Due to the relatively high Verdet constant (∼70 rad/T/m) and suitable rheology of the glass melt speculated from the thermal analysis, TASB glass system in this work is adaptable to stable fiber‐based Faraday effect devices. [ABSTRACT FROM AUTHOR]

Periodic arrays of metallic nanoparticles act as metasurfaces to control light at the interface. Although the combination of a variety of functional materials with metasurfaces should open a rich scientific research field, the application degree of freedom is limited severely by the fabrication process. We developed a metasurface sticker that can be stuck on any surface and gives control over in- and outcoupling of light. We demonstrate a photoluminescence outcoupling by placing a sticker on the luminescent layers: the emission pattern is modulated both spatially and spectrally in a way defined by the metasurface sticker. The sticker is useful for enhancing optical response from many different surfaces including those that are incompatible with the nanofabrication processes and should help the integration of metasurfaces into functional devices. [ABSTRACT FROM AUTHOR]

Aluminum (Al) is known as a plasmonic material effective in a wide frequency range up to the ultraviolet, while its plasmonic properties in the near infrared region have been less explored. In this study, up‐conversion (UC) photoluminescence is amplified by using an Al nanostructure to demonstrate that Al is a useful plasmonic material in the near infrared region as well. A periodic lattice of Al nanocylinders is selected as a plasmonic nanostructure, where the size of nanocylinder and the period of the lattice are tuned to match both the localized surface plasmon resonance and in‐plane diffraction to the absorption wavelength (λ = 980 nm) for the UC process. Core–shell‐type UC nanoparticles (NPs) are designed to suppress the energy transfer from NPs to Al cylinders which reduces the UC photoluminescence intensity. The resulting optimized core–shell UCNPs combined with the Al plasmonic lattice leads to over 100‐fold enhancement of UC intensity. The use of Al instead of conventional Au as a plasmonic material is beneficial from the point of view of low cost and abundance of element. [ABSTRACT FROM AUTHOR]

An enhanced emission of high quantum yield molecules coupled to dielectric metasurfaces formed by periodic arrays of polycrystalline silicon nanoparticles is demonstrated. Radiative coupling of the nanoparticles, mediated by in‐plane diffraction, leads to the formation of collective Mie scattering resonances or Mie surface lattice resonances (M‐SLRs), with remarkable narrow line widths. These narrow line widths and the intrinsic electric and magnetic dipole moments of the individual Si nanoparticles allow resolving electric and magnetic M‐SLRs. Incidence angle‐ and polarization‐dependent extinction measurements and high‐accuracy surface integral simulations show unambiguously that magnetic M‐SLRs arise from in‐ and out‐of‐plane magnetic dipoles, while electric M‐SLRs are due to in‐plane electric dipoles. Pronounced changes in the emission spectrum of the molecules are observed, with almost a 20‐fold enhancement of the emission in defined directions of molecules coupled to electric M‐SLRs, and a fivefold enhancement of the emission of molecules coupled to magnetic M‐SLRs. These measurements demonstrate the potential of dielectric metasurfaces for emission control and enhancement, and open new opportunities to induce asymmetric scattering and emission using collective electric and magnetic resonances. [ABSTRACT FROM AUTHOR]

We have developed a technique by which poling and ion implantation in solid state are simultaneously accomplished. The technique has been applied to 2Ag2O·3Na2O·25ZnO·70TeO2 (in mol %) glass. The glass is sandwiched by two cover glasses containing Na+ and then the thermal poling is carried out. We have accidentally found that Ag nanoparticles are selectively precipitated in the vicinity of the anode-side glass surface. X-ray photoelectron spectroscopy reveals that the glass composition of the anode-side glass surface becomes rich in Na+ after the thermal poling, which is caused by the Na+ implantation from the cover glass at the anode side. [ABSTRACT FROM AUTHOR]

Abstract Sm3+-doped aluminoborate glasses containing Ag nanoparticles have been synthesized via a melt-quenching technique. After heat treatment, the surface plasmon resonance (SPR) absorption peak of Ag nanoparticles appears approximately at the wavelength λ = 425 nm. With the precipitation of the Ag nanoparticles, the intensities of visible (λ = 600 nm) and near-infrared (λ = 950 nm) photoluminescence are enhanced under excitation at λ = 400 nm up to 39.8% and 25% that of the as-made glass, respectively. Moreover, the excitation of Sm3+ at λ = 473 nm for the sample heat-treated at 500 °C shows higher enhancement in near-infrared photoluminescence by 55.5% (λ = 950 nm). This enhancement is attributable to the intensified localized electromagnetic field accompanied by the excitation of SPR. The presence of Ag nanoparticles assists the conversion of UV light into visible and near-infrared light, which can induce a photoelectric effect for Si and other semiconductors used in solar cells. Highlights • Ag nanoparticles increase the intensity of visible and near-infrared photoluminescence of Sm3+ in aluminoborate glass. • Localized surface plasmon resonance of Ag enhances the excitation of Sm3+. • Optimal heat treatment temperature to maximize the photoluminescence intensity is presented. [ABSTRACT FROM AUTHOR]

We synthesized thin films, consisting of yttrium aluminum garnet doped with Ce 3+ (YAG:Ce), using the mist chemical vapor deposition (CVD) method, which allows the fabrication of high-quality thin films under atmospheric conditions without the use of vacuum equipment. Under a deposition rate of approximately 1 μm/h, the obtained thin films had a typical thickness of 2 μm. The XRD analysis indicated that the thin films consisted of single-phase YAG:Ce. The Rutherford backscattering confirmed the stoichiometry; the composition of the film was determined to be (Y, Ce) 3 Al 5 O 12 , with a Ce content of Ce/(Y+Ce)=2.5%. The YAG:Ce thin films exhibited fluorescence due to the 5d–4f electronic transitions characteristic of the Ce ions occupying the eight-coordinated dodecahedral sites in the YAG lattice. [ABSTRACT FROM AUTHOR]

We have fabricated a highly crystalline thin film of indium tin oxide (ITO) to examine the relationship between properties of charge carriers and their collective plasmonic response. The ITO thin film with atomically flat surface was epitaxially grown on a yittria-stabilized zirconia substrate by using pulsed laser deposition. Attenuated total reflectance spectra for the infrared (IR) region in the Otto configuration show a dip for p -polarized light, corresponding to an excitation of surface plasmon polaritons. The IR reflectivity data can be well reproduced by the theoretical calculation based on the Fresnel model, in which the dielectric function of ITO is deduced from the Drude theory using the carrier density and mobility obtained by Hall measurement. The high carrier mobility in single crystalline ITO thin film is found to result in a significantly low optical loss in the IR region (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Exciton‐polaritons (EPs) are hybrid light–matter quasi‐particles with bosonic character formed by the strong coupling between excitons in matter and photons in optical cavities. Their hybrid character offers promising prospects for the realization of non‐equilibrium Bose–Einstein condensates (BECs), and room‐temperature BECs are possible with organic materials. However, the thresholds required to create BECs of organic EPs remain still high to allow condensation with electrical injection of carriers. One of the factors behind these high thresholds is the very short cavity lifetimes, leading to a fast EP decay and the need to inject higher exciton densities in the reservoir to form the condensate. Here a BEC of EPs in organic dyes and all‐dielectric metasurfaces at room temperature is demonstrated. By using dielectric metasurfaces that exhibit very low losses it is possible to achieve cavity lifetimes long enough to allow an efficient population of EP states via vibrational relaxation and radiative pumping. It is shown how polariton lasing or non‐equilibrium Bose–Einstein condensation is achieved in several cavities, and one of the lowest reported thresholds for BECs in organic materials is observed. [ABSTRACT FROM AUTHOR]

Abstract: Wavelength-selective enhancement of optical birefringence has been observed in a tellurite glass containing silver nanoparticles (Ag NPs) induced via thermal poling. The birefringence appears as an optical rotation of linearly polarized light; a large optical rotation is observed at around the wavelength of localized surface plasmon resonance (LSPR) of Ag NPs. The optic axis is oriented along the electric field applied during the thermal poling, suggesting that birefringence induced in the glass matrix through the thermal poling is drastically enhanced by the NPs at around the LSPR. Because of the birefringence of the matrix, the wavelength of LSPR shifts depending on the polarization state of the incident light, which in turn induces the polarization dependence of the real part of the refractive index via the Kramers–Kronig relation. [Copyright &y& Elsevier]

Abstract: We have prepared macroporous Y3Al5O12 (YAG) monoliths doped with rare earth (RE) ions (RE=Ce, Eu, Sm, and Pr) via the ionic precursor-derived sol–gel reaction accompanied by phase separation and investigated their fluorescence and scattering properties. YAG monoliths with well-defined bicontinuous macropores and skeletons were synthesized from the mixture of water and ethanol containing yttrium(III), aluminum(III), and RE(III) salts using propylene oxide as a gelation initiator and poly(ethylene oxide) as a phase separation inducer. X-ray diffraction measurements reveal that the sample as-dried and that heat-treated at 700°C are amorphous, while a single crystalline phase of YAG is precipitated in the samples heat-treated at temperatures between 800 and 1100°C. The macroporous YAG:RE ceramics heat-treated at 800°C and higher temperatures exhibit fluorescence due to 4f–5d (Ce3+) and 4f–4f (Eu3+, Sm3+, Pr3+) electronic transitions characteristic of the RE ions occupying the eight-coordinated dodecahedral sites in YAG lattice. Coherent backscattering experiments indicate that the scattering strength is enhanced by the densification of skeletons in macroporous YAG monoliths, depending on the heat treatment temperature. [ABSTRACT FROM AUTHOR]

A 65-year-old man was referred to our hospital following repetitive chest pain. Invasive coronary angiography showed an intermediate stenosis of the proximal left anterior descending artery (LAD), and a coronary fistula originating distal to the stenosis draining into the main pulmonary artery. To evaluate the functional abnormality arising from the stenosis and coronary steal due to the fistula, fractional flow reserve (FFR) was measured using a pressure wire with pullback recording. The FFR value was 0.74 at the distal LAD, 0.78 distal to the fistula, 0.81 proximal to the fistula (distal to the stenosis), and abruptly increased to 1.0 proximal to the stenosis. Based on these FFR results, percutaneous coronary intervention was performed to the stenosis. After stent placement, the FFR value improved to 0.87 at the distal LAD, and no abrupt pressure gradient was observed beyond the fistula and the stent. FFR-guided intervention with pullback pressure recording could be a useful and practical method to apply in cases with coronary stenosis complicated by coronary fistula in the same vessel. [ABSTRACT FROM AUTHOR]

Abstract: Temperature dependence of scattering strength for the visible light (488nm) has been investigated for a siloxane-based macroporous monolith infiltrated with liquid crystal molecules. A macroporous gel with interconnected pores and organosiloxane skeletons is prepared via a sol–gel route by inducing the phase separation parallel to the hydrolysis and condensation of silicon alkoxide. The interconnected macropores of the dried gel are infiltrated with liquid crystal 4-cyano-4′-n-pentylbiphenyl (5CB) which undergoes the phase transition between nematic and isotropic at 35°C. Temperature variation of the scattering strength for 5CB-filled gel is measured by means of coherent backscattering and total transmission, both of which exhibit a significant change in transport mean free path at around the phase transition temperature of 5CB. The results indicate that the scattering strength of 5CB-filled monolith gel can be tuned externally via temperature. [Copyright &y& Elsevier]

Abstract: Sm2+-doped Al2O3–SiO2 glasses with three-dimensionally interconnected macroporous morphology have been prepared via the alkoxide-derived sol–gel process containing poly(ethylene oxide) and SmCl3 ·6H2O. The macroporous morphology is obtained by concurrently inducing the phase separation and sol–gel transition. When the macroporous aluminosilicate glasses doped with Sm2+ are irradiated with a visible light laser at the wavelength of 488nm, a hole or a dip appears in the plot of fluorescence intensity versus the incident angle of laser beam, indicating that the valence state of Sm2+ is spatially modulated through the interference of multiply scattered light. The hole profile can be controlled by adjusting the macroporous morphology. [Copyright &y& Elsevier]

Abstract: We have investigated the spatial distribution of Sm2+ inside macroporous alumina–silica (Al2O3–SiO2) glasses having three-dimensionally interconnected skeletons. The Sm2+-doped Al2O3–SiO2 glasses are prepared via an alkoxy-derived sol–gel route in the presence of poly (ethylene oxide) and SmCl3·6H2O. The well-defined macroporous morphology is obtained by the concurrence of the phase separation and the sol–gel transition. The reduction of Sm3+ to Sm2+ is accomplished by heat treatment under a reducing atmosphere. Two-dimensional images of the fluorescence due to the 4f–4f transition of Sm2+ with the aid of a laser scanning confocal microscope reveal the spatially uniform dispersion of Sm2+ inside the Al2O3–SiO2 skeleton. [Copyright &y& Elsevier]

Abstract: We have fabricated a dielectrically disordered medium based on monolithic silica (SiO2) with interconnected macropores by a sol–gel method. Macroporous SiO2 is obtained in a system containing tetramethoxysilane, poly(ethylene glycol), acetic acid, and water. The macroporous structure is formed when the transient structure of phase separation developed during the hydrolysis and polycondensation of alkoxysilane is frozen by the sol–gel transition. An active disordered medium is prepared by infiltrating a methanol solution of rhodamine 6G (R6G) dye into the macropores of the monolithic SiO2. When R6G dye molecules filled in the interconnected macropores are pumped by a frequency-doubled Nd:YAG laser, a drastic narrowing of dye emission accompanied by an increase in the peak intensity is observed. The large optical gain is ascribed to the increase in residence time of emitted photons in the active region due to multiple scattering. [Copyright &y& Elsevier]

Herein, we demonstrate that rapid thermal annealing allows achieving close-to-one photoluminescence quantum yield while preserving the transparency of rare-earth nanocrystal films, which further enables their integration with nanophotonics. The combination with periodic arrays of aluminum nanodisks that support collective plasmonic resonances leads to enhanced directional emission. [ABSTRACT FROM AUTHOR]

Photoreactive random media containing silver nanoparticles (Ag NPs) have been fabricated, and hole burning effects based on the interference of multiply scattered light have been investigated. Through the analysis of hole profiles, transport mean free path ℓ is estimated for the light with the wavelength of 585 nm. We find that ℓ in the samples embedded with Ag NPs is much shorter compared with that in a medium containing the same amount of titania (TiO2) NPs, indicating that Ag NPs scatter 585 nm lightwaves much stronger than TiO2 NPs because of their larger scattering cross sections due to the localized surface plasmon resonance. [ABSTRACT FROM AUTHOR]

A photoreactive random medium with tunable diffusion constant D is fabricated by infiltrating Sm2+-doped macroporous aluminosilicate glass with liquid crystal (LC). Time-resolved transmission experiment reveals that D in the LC-infiltrated sample changes abruptly at around 35 °C due to the phase transition of LC between nematic and isotropic. The hole burning effect based on the interference of multiply scattered light is investigated with a particular motivation of controlling hole burning properties externally via temperature. We demonstrate that the holes are separately registered in each LC phase and can be detected selectively depending on the temperature. [ABSTRACT FROM AUTHOR]

The authors report on an intense blue emission centered at 420 nm under ultraviolet excitation from pentavalent tantalum ion-doped silicate glasses. The blue emission is distinctly different from emission due to defects in silica glass, which is also reflected in both absorption spectrum and remarkably enhanced emission. The authors suggest that localized Ta 5d0 energy level is responsible for the blue emission. [ABSTRACT FROM AUTHOR]

H-type supramolecular polymers with preferred helicity and highly efficient emission have been prepared from the self-assembly of chiral tetraphenylene-based monomers. Implementation of the one-dimensional fibers into dielectric nanoparticle arrays allows for a significant reshaping of fluorescence due to weak light–matter coupling. [ABSTRACT FROM AUTHOR]

We report on the design, fabrication, and analysis of a tunable device combining nanoparticle arrays that support collective surface lattice resonances (SLRs) with liquid crystals (LCs). The optoelectronic tunability of the nematic LC and the dependency of sharp SLRs on the refractive index of the environment are exploited to achieve spectral tunability. This tunability is electrically controlled by switching between planar and homeotropic states in the LC, which allows for a rapid and reversible tuning of the SLR wavelength with a large degree of control. This device also offers the possibility to switch "on" and "off" the presence of a quasi-guided mode in the indium tin oxide electrode. The manipulation of these resonances with an external parameter can be used to expand the functionalities of plasmonic metasurface devices. [ABSTRACT FROM AUTHOR]

Using a particle swarm optimization algorithm and finite-difference in time-domain simulations, we optimize the coupling strength between excitons in poly(3-hexylthiophene-2,5-diyl) (P3HT) and surface lattice resonances in open cavities defined by arrays of aluminum nanoparticles. Strong light–matter coupling and the formation of exciton-polaritons are demonstrated. Nanoparticle arrays with optimal dimensions have been fabricated and measured, validating the predictions by the numerical method. P3HT is a regioregular semiconducting polymer used as a donor material in acceptor–donor blends for organic photovoltaic applications. Our results demonstrate the efficacy of the proposed method for the optimization of light–matter coupling and its potential application for the enhanced performance of optoelectronic devices. [ABSTRACT FROM AUTHOR]

We have synthesized polycrystalline thin film composed of a single phase of metastable bismuth iron garnet, Bi 3 Fe 5 O 12 , on a fused silica substrate, one of the most widely utilized substrates in the solid-state electronics, by using mist chemical vapor deposition (mist CVD) method. The phase purity and stoichiometry are confirmed by X-ray diffraction and Rutherford backscattering spectrometry. The resultant thin film shows a small surface roughness of 3.251 nm. The saturation magnetization at room temperature is 1200 G, and the Faraday rotation angle at 633 nm reaches −5.2 deg/μm. Both the magnetization and the Faraday rotation angles are somewhat higher than those of polycrystalline BIG thin films prepared by other methods. [ABSTRACT FROM AUTHOR]

We have prepared a three-dimensional magnetophotonic crystal and observed modulated Faraday rotation around its photonic band gap. The magnetophotonic crystal was prepared by the self-assembly of highly monodispersed silica spheres, which were heavily impregnated with maghemite (γ-Fe2O3) nanoparticles. The slab sample with a thickness of 10 μm shows a clear photonic band gap centered at λ=620 nm in optical transmittance. Faraday rotation is notably modified inside the photonic band gap. [ABSTRACT FROM AUTHOR]

An array of nanocylinders can modulate photoluminescence (PL) of emitters via simultaneous excitation of local resonances and light diffractions. Regarding the local resonance, localized surface plasmon polaritons (LSPP) of metals has been commonly applied, while the Mie resonance of dielectrics can also be a candidate. Since these two resonances are excited in different classes of materials, experimental comparisons between their enhancement efficiencies are rarely made. In this study, we fabricated periodic arrays of Si and Al nanocylinders with the identical design and compared their PL outcoupling abilities. We deposited ultraviolet (UV)-absorbing and highly luminous dielectric films on the arrays and observed enhanced PLs from the films on the nanocylinder arrays upon a UV laser excitation. The optical transmission with varied incident angles revealed that the dispersion of the hybrid mode of diffraction with the Mie resonance in the Si nanocylinder array was sharper than that of the diffraction-LSPP hybrid in the Al nanocylinder array. The PL enhancement by the Si nanocylinder array was more selective both spectrally and spatially than that by the Al nanocylinders, which could be attributed to the difference between the mode profiles. Our findings experimentally verified the advantage of choosing Si as a constituent of the cylinder array to provide highly directional light sources. [ABSTRACT FROM AUTHOR]

A 58-year-old man was referred to our hospital because of chest pain. The 12-lead electrocardiogram (ECG) revealed ST-segment elevation in II, III, and a Vf with advanced heart block. Transthoracic echocardiography demonstrated aortic root dilatation at the sinus of Valsalva, moderate aortic regurgitation, and decreased wall motion in the inferior part of the left ventricle. Non-ECG-gated enhanced computed tomography (CT) did not reveal an aortic dissection. The patient underwent emergent coronary angiography, which revealed a severely narrowed ostium of the right coronary artery (RCA). Percutaneous coronary intervention (PCI) was performed under intravascular ultrasound (IVUS) guidance. IVUS images demonstrated an intimal flap extending from the aortic wall to the proximal RCA, suggesting that a periaortic hematoma in the false lumen compressed the ostium of the RCA, leading to acute myocardial infarction. To recover hemodynamic stability, the RCA ostium was stented. Subsequent ECG-gated enhanced CT clearly depicted the entry point and extension of the dissection localized within the sinus of Valsalva. The dissection likely involved the left main coronary artery and an emergent Bentall procedure was performed. Intraoperative findings confirmed an intimal tear and extension of the dissection. Thus, ECG-gated CT can clearly depict the entry site and extension of a dissection occurring in the localized area that cannot be detected by conventional CT. [ABSTRACT FROM AUTHOR]

Abstract: Macroporous Al2O3–SiO2 glasses doped with Sm2+ have been prepared from a sol–gel system containing aluminum sec-butoxide, tetramethoxysilane, samarium chloride hexahydrate, poly(ethylene oxide), nitric acid, and water. Monolithic gels having interconnected macropores and skeletons are formed by inducing the phase separation parallel to the gelation. The use of aluminum sec-butoxide preheated at 80°C as the starting material enables the incorporation of Al3+ into the gel skeleton up to 20mol% in cation ratio. The maximum amount of Al3+, i.e., 20mol%, is twice as large as that reported in our previous study, where aluminum sec-butoxide was diluted with sec-butanol prior to the hydrolysis. Heat-treatment of Sm3+-doped 20AlO3/2 ·80SiO2 macroporous glass under the reducing atmosphere converts Sm3+ to Sm2+, which is confirmed by the appearance of intense emission peaks attributed to 4f–4f transitions of Sm2+. [Copyright &y& Elsevier]

We report on epitaxial growth and magnetic properties of EuTiO3 thin films with a perovskite structure. Single crystalline EuTiO3 films with atomically flat surface are grown on (001) surface of SrTiO3 by pulsed laser deposition (PLD) and subsequent annealing in reducing atmosphere. The as-deposited films possess the crystal structure with an elongated c-axis and tend to stabilize ferromagnetically ordered Eu2+ spins at low temperatures. Postannealing at 1000 °C relaxes the out-of-plane lattice strain, and brings about a drastic change in magnetic structure; the annealed film becomes an antiferromagnet below Néel temperature of 5.1 K. The change in magnetic properties accompanied by the modification in lattice constant is discussed. [ABSTRACT FROM AUTHOR]

We have prepared glasses having xFeO·(100-x)P2O5 (mol %) (x=50.0,54.0,57.1) compositions by melting under mild reducing condition and found that these glasses exhibit fairly high transmittance in the visible range and large Faraday effect at the wavelength of about 400 nm. 57Fe Mössbauer spectra confirm that almost all the iron ions are present as Fe2+ in the glasses. A spin glass transition is observed at low temperatures in the temperature dependence of magnetic susceptibility. Intense optical absorption in the ultraviolet and infrared wavelength ranges occurs by the charge transfer transition from O2- to Fe2+ and the intra-atomic d-d transition, respectively. The analysis on the wavelength dependence of the Faraday rotation angle using the Van Vleck–Hebb theory has revealed that the charge transfer transition contributes more significantly to the Faraday effect owing to the large effective transition probability, which is comparable to those reported for glasses containing 4f rare-earth ions. The magneto-optical figure of merit shows a maximum at around 380 nm. [ABSTRACT FROM AUTHOR]

Mechanical milling of a mixture of powders composed of 2 mol % MnO2 and 98 mol % ZnO leads to a ferromagnetic phase with Curie temperature above 300 K. The magnetic field dependence of magnetization manifests a residual magnetization of 2.84×10-4 emu/g and a coercive force of 76 Oe at 300 K; the residual magnetization of the as-milled sample is larger than those of heat-treated samples. It is speculated that the ferromagnetic behavior is imposed to Zn-doped manganese oxide phases formed on the surface of MnO2 particles via the mechanical milling. [ABSTRACT FROM AUTHOR]

Self-measured blood pressure at home (HBP) is quite important for the management of hypertension. We hypothesized that winter HBP measured according to the recommendation of the guidelines, but not HBP measured inside bed before getting up, is elevated in response to cold ambient temperatures in winter. This study aimed to investigate differences in HBP measured before and after getting up in winter and summer.Methods: Hypertensive subjects whose blood pressure was stably controlled were enrolled (n = 46, 73 years). They were instructed to measure HBP while in bed just after waking (HBP-bed), in addition to the ordinary HBP measurement in the morning (HBP-morning) according to the guidelines. The mean value of HBP for 7 consecutive days before the day of a regular hospital visit was considered as the HBP of each subject, and characteristics of the winter and summer BPs were investigated.Results: HBP-morning was significantly higher (P <.001) in winter than in summer, but HBP-bed was lower in winter than in summer (P <.05). HBP-morning was significantly higher than HBP-bed in winter, while HBP-morning was not different from HBP-bed in summer, resulting in greater changes in HBP after getting up in winter than in summer (P <.0001). Changes in HBP after getting up were significantly correlated with serum creatinine levels and the urinary albumin-to-creatinine ratio.Conclusions: These findings imply that elevated HBP-morning in winter reflects the response of BP to cold after getting up. Seasonal profiles of HBPs before and after getting up should be noted in the management of hypertension. [ABSTRACT FROM AUTHOR]

Barium zinc phosphate glasses formulated in the xBaO–(60 − x)ZnO–40P2O5 composition line are investigated for their optical, thermal, and chemical characteristics. These as well as small stress‐induced birefringence were found to be governed by the BaO/ZnO substitution. In addition to the characterization of the properties, the phosphate network was qualitatively and quantitatively described in terms of Q2 and Q1 ratios by 1D 31P magic angle spinning nuclear magnetic resonance spectroscopy experiments that also showed the presence of Q0 sites. It turns out that the small perturbations of their photoelastic, magnetic, and chemical characteristics made these glasses very good candidates for use in polarization‐controlling optical devices. [ABSTRACT FROM AUTHOR]

In this study, photoluminescence (PL) under high excitation intensity as a function of crystalline size was systematically investigated through ZnO nanocrystalline films prepared by spin-coating a colloidal solution of ZnO nanoparticles obtained using the microemulsion method. Annealing of the films at 723, 633, and 593 K allowed us to tune the crystalline radius R. PL studies distinguished different regimes of crystalline size according to the ratio of R to the effective Bohr radius aB(R/aB). For the sample annealed at 723 K (R/aB=7.2), the peak of stimulated emission due to the exciton-exciton collisions appeared on the low-energy side of the exciton emission with an increase in excitation intensity. A further increase in excitation intensity eventually resulted in the occurrence of an electron-hole plasma (EHP) accompanied by consequent band gap renormalization, which indicates that high excitation intensity provokes the dissociation of excitons. For the sample annealed at 633 K (R/aB=4.7), the stimulated emission was observed while the transition to EHP was obscure. For the sample annealed at 593 K (R/aB=2.1), only emissions due to the recombination of the electron-hole pair were observed, and stimulated emission did not appear even when the excitation intensity was increased. The transition from free-exciton emission to donor-bound exciton emission was observed in temperature dependence of PL only for the sample with R/aB=7.2. The origin of annihilation of the stimulated emission with a size reduction is discussed based on nonradiative Auger recombination. [ABSTRACT FROM AUTHOR]

Abstract: In contrast to polar cation displacements driving oxides into noncentrosymmetric and ferroelectric states, inversion‐preserving anion displacements, such as rotations or tilts of oxygen octahedra about cation coordination centers, are exceedingly common. More than one nonpolar rotational mode in layered perovskites can lift inversion symmetry and combine to induce an electric polarization through a hybrid improper ferroelectric (HIF) mechanism. This form of ferroelectricity expands the compositional palette to new ferroelectric oxides because its activity derives from geometric rather than electronic origins. Here, the new Ruddlesden–Popper HIF Sr3Zr2O7, which is the first ternary lead‐free zirconate ferroelectric, is reported and room‐temperature polarization switching is demonstrated. This compound undergoes a first‐order ferroelectric‐to‐paraelectric transition, involving an unusual change in the “sense” of octahedral rotation while the octahedral tilt remains unchanged. Our experimental and first‐principles study shows that the paraelectric polymorph competes with the polar phase and emerges from a trilinear coupling of rotation and tilt modes interacting with an antipolar mode. This form of hybrid improper “antiferroelectricity” is recently predicted theoretically but has remained undetected. This work establishes the importance of understanding anharmonic interactions among lattice degrees of freedom, which is important for the discovery of new ferroelectrics and likely to influence the design of next‐generation thermoelectrics. [ABSTRACT FROM AUTHOR]

Abstract: Only mechanical milling of a mixture of powders composed of MnO2 and ZnO brings about a phase which exhibits ferromagnetic behavior at room temperature. The sample just after the mechanical milling without any heat treatments at elevated temperatures clearly manifests a hysteresis loop in magnetic field dependence of magnetization at 300K; the residual magnetization is 2.84×10−4 emu/g and the coercive force is 76Oe. It should be emphasized that the residual magnetization rather decreases when the as-milled sample is heat treated. The ferromagnetic behavior is thought to be attributed to Zn-doped manganese oxide phase formed on the surface region of MnO2 particles. [Copyright &y& Elsevier]

Background and aims Mac-2 binding protein (M2BP) was reported to be a useful biomarker for liver fibrosis and malignant tumors. We hypothesized that expression of M2BP might also change in the process of atherosclerosis. Methods This study included subjects who visited our hospital for a physical checkup. Results The M2BP levels in subjects with hypertension, dyslipidemia, or abnormal glucose metabolism were higher than those in subjects without such risk factors. Moreover, the M2BP levels were associated with severity of cardiovascular risk. Subdivision of M2BP levels into quartiles revealed that M2BP was significantly associated with reactive oxygen metabolites, central systolic blood pressure, and radial augmentation index (AI). Logistic regression analysis with the endpoint of high radial AI (above mean value) showed that high radial AI was independently associated with high M2BP. Conclusions Although the spectrum was narrow as compared to that in cases of hepatic fibrosis, serum M2BP may reflect silent atherosclerosis in apparently healthy subjects. [ABSTRACT FROM AUTHOR]

The crystal structures of europium niobate, EuNbO 3 , have been examined over a wide temperature range between 20 and 500 K using synchrotron X-ray diffraction. We have observed two successive structural phase transitions at 360 and 460 K. Below 350 K, EuNbO 3 adopts an orthorhombic perovskite structure (space group Imma ), which is characterized by NbO 6 octahedral tilting about the pseudocubic two-fold axis. The result differs from previous reports in which EuNbO 3 was assigned to a cubic aristotype (space group Pm 3 ¯ m ) of perovskite at room temperature. At around 360 K, EuNbO 3 undergoes a first-order phase transition to a tetragonal symmetry (space group I 4/ mcm ) with the NbO 6 octahedral tilting about the pseudocubic four-fold axis. As the temperature is further increased, the I 4/ mcm tetragonal phase changes into the Pm 3 ¯ m cubic aristotype at 460 K. The tetragonal-to-cubic transformation is characterized as a continuous phase transition. [ABSTRACT FROM AUTHOR]

Magnetic, optical, and magneto-optical properties have been examined for aluminoborosilicate glasses with high concentration of divalent europium ions. An analysis on temperature dependence of magnetic susceptibility yields positive Weiss temperatures, indicating that magnetic moments of 4f electrons of Eu2+ interact ferromagnetically with each other in the glasses. The glasses show large Faraday rotation angles in the visible range; glass with a composition of 58.0EuO·12.0Al2O3·20.0B2O3·10.0SiO2 (mol%) has a Verdet constant of −1.03min/Oecm (−300rad/Tm) at 633nm. Wavelength dependence of the Verdet constant is interpreted in terms of Eu2+ 4f 7 to 4f 65d 1 electronic transitions based on the Van Vleck–Hebb theory. [ABSTRACT FROM AUTHOR]

Amorphous Eu2TiO4 and EuTiO3 have been studied by a combination of the Faraday effect in the visible region and polarization-dependent x-ray absorption spectroscopy at the Eu M4,5 and L2,3 edges to examine the role of Eu 4f-5d exchange interactions on the ferromagnetic behavior. The bulk-sensitive x-ray absorption spectra (XAS) for Eu L2,3 edges show that most of the europium ions are present as the divalent state in the amorphous Eu2TiO4 and EuTiO3. The Eu M4,5 edge x-ray magnetic circular dichroism (XMCD) signals, measured for the amorphous Eu2TiO4, dramatically increase upon cooling through the Curie temperature (16 K) determined by a superconducting quantum interference device (SQUID) magnetometer. Sum-rule analysis of the XMCD at Eu M4,5 edges measured at 10 K yields a 4f spin magnetic moment of 6.6μB per Eu2+ ion. These results confirm that the ferromagnetic properties exclusively arise from 4f spins of Eu2+ In addition, for both the amorphous Eu2TiO4 and EuTiO3, the temperature and magnetic-field dependence of Eu L2,3 edge XMCD signals can be scaled with the corresponding magnetization measured by SQUID, indicating that the 5d magnetic polarization of Eu2+ is involved in the process to cause the ferromagnetic interaction between Eu2+ ions. We further discuss the origin of ferromagnetism in the amorphous system on the basis of the energy diagram of Eu 4f and 5d levels deduced from the Faraday effect in the visible region. From the wavelength dependence of Faraday rotation angles of the amorphous EuO-TiO2 system in comparison with those of the divalent Eu chalcogenides as reported previously, it is found that the magnitude of crystal-field splitting of Eu 5d levels in the former is on the same order as that in the latter, which explains an enhanced ferromagnetic exchange interaction between Eu 4f and 5d states. [ABSTRACT FROM AUTHOR]

Objectives The aims of this study were to assess the correlations between the Geriatric Oral Health Assessment Index ( GOHAI) and the Oral Health Impact Profile-14 ( OHIP-14) and to examine which survey is more sensitive to objectively measured oral function in the Japanese elderly. Methods The subjects were 290 community-dwelling, cognitively healthy, and independently living people over the age of 60 years (mean: 66.3 years). Measures included the GOHAI and OHIP-14 questionnaires, as well as self-rating of general and oral health, dry mouth, number of residual teeth, and objective values of occlusal force, masticatory performance, and salivary flow rate. Bivariate and linear regression analyses were used to identify which of these variables predicted GOHAI and OHIP-14 scores. Results Spearman's correlation coefficient between the GOHAI and OHIP-14 scores was 0.728 ( P < 0.001), although the OHIP-14 showed a greater number of 0 scores, suggesting a greater floor effect. At the bivariate level, self-rating of general and oral health, dry mouth, number of residual teeth, occlusal force, and masticatory performance were associated with GOHAI and OHIP-14 scores. Multiple linear regression analyses showed that after controlling for the other significant variables, both the occlusal force (standardized regression coefficient [β] = −0.164, P = 0.004) and masticatory performance (β = −0.125, P = 0.019) had significant associations with the GOHAI score, whereas this association was not found with the OHIP score. Conclusions Although the GOHAI and OHIP-14 had a strong correlation, the GOHAI was more sensitive to the objective values of oral functions among independently living elderly persons in Japan. [ABSTRACT FROM AUTHOR]

We have investigated the local structure of amorphous oxides in EuO-TiO2 system to understand the mechanism that gives rise to curious ferromagnetic properties recently observed in the system. X-ray absorption spectroscopy has been performed on amorphous EuTiO3 and Eu2TiO4 thin films prepared by the pulsed-laser-deposition method. The Ti K-edge X-ray absorption near-edge structure ( XANES) and extended X-ray absorption fine structure ( EXAFS) data analyses reveal that the coordination number of Ti4+ in the amorphous thin films is around 4, which is in sharp contrast to their crystalline counterparts, where Ti4+ ions are octahedrally coordinated by oxide ions. It is therefore inferred that Ti4+ acts as a network-forming cation in the random network structure of the amorphous oxides. From the Eu L3-edge EXAFS data analyses, it is found that the coordination number of Eu2+ is much lower and the nearest Eu-O bond length is shorter in the amorphous thin films than in the crystalline counterparts. The amorphization-induced enhancement of ferromagnetic interactions observed in the EuO-TiO2 system is discussed in terms of the local environment around Eu2+ ions. [ABSTRACT FROM AUTHOR]

Measurements of fundamental magnetic properties including not only dc and ac susceptibilities but also magnetic aging effects have been performed for aluminoborate glasses with high concentrations of iron and rare-earth R3+ ions (R = Sm, Gd, and Tb) in order to give an insight into the magnetic structures and interactions in amorphous oxides containing both 3d transition metal and 4f rare-earth ions, which manifest magnetic interactions that differ from each other. We demonstrate that the antiferromagnetic interactions between iron and rare-earth ions as well as those between iron ions play a significant role for their magnetic properties, while those between rare-earth ions are of little importance. Most of the rare-earth ions remain paramagnetic even below the spin-freezing temperatures under the strong molecular field caused by the spin-glass freezing of the iron ions, as in the case of rare-earth garnet ferrites. [ABSTRACT FROM AUTHOR]