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This report presents the luminescence properties of Tb3+-doped oxide glasses with high Gd2O3 (25 mol%) concentration under UV and X-ray excitation. The intense green 5D4 7FJ luminescence is observed with strong luminescence quenching of the 5D3 level due to cross-relaxation process. Energy transfer from Gd3+ to Tb3+ ions is confirmed by both luminescence spectra and decay measurements. The integral scintillation efficiency obtained for the 0.5 wt% Tb3+-doped glass under X-ray excitation is of about 40% of that of the reference Bi4Ge3O12 crystal.

Ce3+-doped high silica glass was prepared by impregnation of Ce ions into a porous silica glass followed by high temperature sintering in a CO reducing atmosphere. The characteristic emission of Ce3+ 5d → 4f transition peaking around 375 nm is observed in its luminescence spectra under UV and X-ray excitation. Its photoluminescence decay is governed by several tens of nanoseconds decay time. Its integral scintillation efficiency is comparable to that of a Bi4Ge3O12 (BGO) crystal under X-ray excitation. Scintillation light yield under gamma and alpha excitation was measured and compared with that of BGO.

The visible upconversion luminescence properties of Pr 3+ /Nd 3+ co-doped CsCl modified Ge–Ga–S glasses are investigated. Enhanced emissions from Pr 3+ ions via energy transfer from Nd 3+ ions are observed at 488, 678 and 729 nm. The possible mechanisms accounting for the enhanced Pr 3+ emissions and upconversion emissions of Nd 3+ , i.e. energy transfer upconversion (ETU) are discussed. The results show that the CsCl modified Ge–Ga–S glasses are promising luminescent materials for solid state lasers and displays, etc.

We report on the precipitation of Si nanocrystals inside a borosilicate glass by using an 800 nm, 250 kHz femtosecond laser irradiation, which was confirmed with X-ray diffraction, Raman spectra and transmission electron microscopy analyses. Refractive index profile reveals that the refractive index of the Si nanocrystals precipitated region increased up to 8.7% in comparison with that of the unirradiated area, leading to a large diffraction efficiency of the fabricated dot structure. Furthermore, the third-order optical nonlinearity of the Si nanocrystals precipitated glass is greatly enhanced based on the Z -scan measurement. These results may find applications for the fabrication diffractive optical devices and optical switches.

Permanent microscale bubbles with varied size and number density are induced in borosilicate glasses by adjusting the focusing depth (FD) of a tightly focused femtosecond laser. With continuously increasing of the focusing depth, the average size of generated bubbles experiences an increase–decrease process. However, the number density of generated bubbles experiences an opposite changing process compared to the change of the size. The possible mechanism for the bubble generation and changing with the focusing depth has been discussed.

A new kind of germanate glass co-doped with Yb 3+ –Ho3 + was prepared. The J-O parameters were calculated to be Ω 2 = (6.59 ± 0.21) × 10 − 20 cm 2 , Ω 4 = (2.77 ± 0.36) × 10 − 20 cm 2 , and Ω 6 = (1.90 ± 0.25) × 10 − 20 cm 2 . The little overlap between the absorption cross section and stimulated emission cross section indicates a non-resonant energy transfer process. The calculation demonstrates that the energy transfer between Yb 3+ and Ho 3+ is one-phonon assisted in a great measure. The gain coefficient of Ho 3+ at 2.0 μm was also calculated. The fluorescence measurement shows the Yb 3+ co-doping enhances the 2.0 μm emission remarkably.

Transparent glass samples doped with bismuth nanoparticles are prepared by heat treatment of as-made glass samples. According to the results of X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectra, Bi nanoparticles are well distributed inside glasses after heat treatment. The average size of Bi nanoparticles increases with the increasing of heat treatment temperature. Because of the size effect and multiple scattering of nanoparticles, the fundamental absorption edge shows a red-shift behavior with the increasing of heat treatment temperature. Nonlinear optical properties of Bi nanoparticles doped glasses are investigated by using Z-scan technique. The maximum value of χ (3) of the glasses is estimated to be 2.49 × 10 − 7 esu at 800 nm. These results indicate that Bi nanoparticles doped glasses may be promising as material for optical switching.

We report on fabrication of large-volume, square-shaped microfluidic chamber embedded in glass by scanning a tightly focused femtosecond laser beam inside a porous glass immersed in water. After the hollow structure is created in the porous glass substrate, the fabricated glass sample is post-annealed at 1,050°C during which it can be sintered into a compact glass. By the use of this technique, a 1 mm × 1 mm × 100 μm microchamber connected to four microfluidic channels is created inside the transparent glass substrate, showing that our technique allows for fabrication of not only thin channel structures with arbitrary lengths and configurations, but also hollow structures with infinitely large sizes.

A spectroscopic investigation of Eu{sup 2+}/Dy{sup 3+} codoped SrO-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3} glass-ceramic is presented. The sample exhibits green emission excited by ultraviolet (UV) light and near-IR femtosecond (fs) laser. The emission profile obtained by near-IR fs laser irradiation is similar to that by UV excitation, indicating that both of the emissions come from 5d {yields} 4f transition of the Eu{sup 2+} ions. The relationship between the upconversion luminescence (UCL) intensity and pump power reveals a two-photon process in the conversion of near-IR radiation to the green emission. The possible mechanism of UCL from such glass-ceramic is proposed.

A novel Tm 3+ -doped lead silicate glass with good thermal stability was prepared in this work. Through thorough investigation of 2 µm luminescent properties of the glasses, optimal Tm 2 O 3 doping concentration was checked to be 3 wt%. Double cladding fiber was prepared by stacking method. As a result, 2 µm laser output was realized in a 40 cm fiber and the maximum output power reached 70 mw.

α-Bi 2 O 3 nanoparticles have been produced by femtosecond laser ablation in ethanol at room temperature. Their crystal structure, crystal phase, shape and size distribution, and photophysical property are investigated using X-ray diffraction, Raman, transmission electron microscopy (TEM), high-resolution TEM and UV–vis spectroscopy. The α-Bi 2 O 3 nanoparticles produced by laser ablation with two particle size population distributions having the mean particle size of ∼10 and ∼60 nm exhibited a good photocatalytic activity on the photodegradation of indigo carmine under 365 nm light emitting diode irradiation.

Long lasting phosphorescence has been observed in oxygen-deficient zinc–boron-germanosilicate glass–ceramics after 254 nm ultraviolet lights irradiation at room temperature. Electron spin resonance (ESR) spectrum confirms the presence of two paramagnetic centers. And the ESR signal shows a synchronized decay process with afterglow intensity after removing the excitation light, suggesting the afterglow is associated with the paramagnetic centers which are generated during the irradiation. Based on the approximate t −1 decay law of the phosphorescence intensity, the long lasting phosphorescence is attributed to thermal assisted tunneling recombination between pairs of distant electrons and Ge-related oxygen-deficient centers.

We report a large-mode-area neodymium-doped silicate photonic bandgap fiber. The concept of power delocalization rather than confinement loss differentiation was considered to theoretically determine the structure parameters, and the near single mode operation of the fabricated fiber was experimentally demonstrated. An output power of 3.1 W with a slope efficiency of 48% was obtained for a 75-cm-long fiber.

The laser behavior of a centimeter-scale Er3+/Al3+ codoped silica fiber with core numerical aperture and core diameter of 0.15 and 8 μm, respectively, is reported. The core glass was prepared by the sol-gel method combined with high-temperature sintering; it contained Er3+ ion concentration as high as 1.32×1020 ions/cm3 and an Al/Er mole ratio of 10. The high doping homogeneity of Er3+ ions in the fiber core was confirmed by an electron probe microanalyzer element scanning, long Er3+: I13/24 emission lifetime of 11.4 ms, and low refractive index fluctuation of fiber core (±1×10-4). The signal gain of fibers with 4.6 cm, 10 cm, and 16 cm lengths was tested in the 1500-1620 nm range. A gain of 7 dB is achieved at 1560 nm in a 16-cm-long EDF under 230 mW pump power. Aimed for CO2 sensor application, the laser behavior of Er/Al codoped fiber was tested at 1572 nm. A slope efficiency of 12% and an output power of 15 mW were achieved in a 10-cm-long fiber under 166 mW absorbed pump power. The newly developed silica fiber is promising for use in high-repetition-rate lasers.

RE 3+ -Yb 3+ (RE = Er, Tm, and Tb) codoped lanthanum aluminum germanate LaAlGe 2 O 7 (LAG) glasses are prepared by melt-quenching method. The blank LAG glass has good transparency in UV/VIS/NIR/MIR range, which makes it suitable for RE ions doping. The doped glasses show strong upconversion (UC) emission under the excitation of a 980 nm laser diode assisted by two or three photons. The UC from Er 3+ /Yb 3+ and Tm 3+ /Yb 3+ codoped LAG glasses show high color purity. The mechanism is also discussed to explain the UC processes.

The near IR emission spectra of Tm/Er-codoped GeS2–In2S3-based chalcohalide glasses are studied with an 808 nm laser as excitation source. A broad emission with a full-width at half-maximum of ∼170 nm is recorded in a 0.5Tm2S3–0.1Er2S3-codoped 70GeS2–20In2S3–10CsBr (in mol%) glass. The luminescence mechanisms are discussed with different CsI concentration, different halogen atoms, and different In content. These results suggest that both halogen (X) atoms and [InSxX4−x] structural units can enhance the emission intensity located at 1460 nm.

Cu-doped and Cu/Al-codoped high silica glasses (HSGes) are prepared by doping Cu2+ ions or codoping Cu2+ ions and Al3+ ions in porous glasses and then sintering at 1200 °C in air and the reduction of Cu2+ ions is observed in Cu/Al-codoped HSGes. With increasing the Al/Cu molar ratio, the color of the samples changes from brown to colorless gradually. Strong and broad glaucous emission from the monomer and dimmer Cu+ ions are observed when exciting the colorless samples with ultraviolet light. Absorption, photoluminescence, electron spin resonance (ESR) spectra and X-ray photoelectron spectroscopy (XPS) are carried out to investigate this phenomenon. The mechanism of this change is presented.

The luminescent properties of Eu 3+ -doped porous glass were investigated and reduction of Eu 3+ to Eu 2+ was observed when the Eu 3+ -doped porous glasses were heat treated in air. The absorption, emission and excitation spectra of Eu 3+ -doped porous glasses were measured and the results significantly depended on the treating temperature. The integral intensity of Eu 3+ and Eu 2+ ions at different temperatures was also investigated to investigate this reduction process. Electron spin resonance (ESR) spectra of the samples were also measured, which also confirmed the reduction effect. A possible mechanism was discussed to explain this process.

Poly (vinyl alcohol) (PVA) and poly (vinyl pyrrolidone) (PVP) nanofibers embedding Ag nanoparticles (5–18 nm) have been prepared successfully by electrospinning at room temperature. Scanning electron microscope (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier transform IR spectra (FTIR), and Raman scattering were used to characterize the structure and properties of Ag nanoparticle-embedded PVA and PVP nanofibers before and after heat treatment at different temperature. The antibacterial activity of Ag nanoparticle-embedded PVP nanofibers after heat treatment was also tested, which indicated that the biological activity of yeast cells was effectively inhibited by these Ag nanoparticle-embedded PVP nanofibers.

Face-centered cubic Ag porous films have been prepared directly from the heat treatment of AgNO3-doped poly(vinyl alcohol) (PVA) electrospun nanofibers. Using Rhodamine B (RB) as the probing molecule, the surface-enhanced Raman scattering (SERS) effect of Ag porous films was demonstrated. The antibacterial activity of Ag porous films was also studied in this work. The propagation and biological activity of yeast cells were effectively inhibited by Ag porous films. These functional Ag porous films were expected to be applied in many fields, such as catalysis, diagnostics, sensors and antibacterial, etc.

The Nd3+, Yb3+-doped and Nd3+–Yb3+-codoped high silica glasses (HSGs) were fabricated by sintering porous glasses impregnated with Nd3+ and Yb3+ ions solutions. The Judd–Ofelt theory was used to study the spectroscopic properties of Nd3+-doped HSGs. Large parameter Ω2 of Nd3+-doped HSGs suggests a lower centrosymmetric coordination environment around the Nd3+ in HSG. The spontaneous emission probability and emission cross-section (σem) of Yb3+-doped HSGs are obtained. A broad emission band from 950 to 1,100 nm was detected when the Nd3+–Yb3+-codoped HSG was excited by 808 nm LD. The energy transfer process from Nd3+ to Yb3+ in HSG was described in this paper.

One-dimensional TiO2:xSm3+ microfibers and microbelts were prepared by electrospinning. X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectrometer (EDS), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), electron paramagnetic resonance (EPR), and polarized luminescence measurements were performed to characterize these TiO2:xSm3+ microfibers and microbelts. SEM and HRTEM results indicate that TiO2:xSm3+ microfibers calcined at different temperature are belt-like. The average width and thickness of TiO2:xSm3+ microbelts calcined at 700 °C is about 1.0 and 0.4 μm, respectively. Under ultraviolet excitation (λex = 330 nm) and commercial 365 nm UV lamp excitation, these TiO2:xSm3+ microbelts show intense 4G5/2 → 6H5/2,7/2,9/2 emissions of Sm3+ ions. Polarized luminescence measurement confirms that the luminescence of single TiO2:xSm3+ microbelt is linear polarization.

In the present paper, we investigate the near-infrared (NIR) luminescence of Tb3+–Yb3+ codoped lanthanum borogermanate (LBG) glasses under visible and ultraviolet light excitation. The results indicate that NIR quantum cutting occurs through cooperative energy transfer from Tb3+ to Yb3+ ions when only 4f8 levels of Tb3+ ions are excited in the wavelength region of 300–490 nm. The highest quantum efficiency under the excitation 5D4 level of Tb3+ at 484 nm is 146%. Ultraviolet excitation that populates the charge transfer band (CTB) of Yb3+ near 270 nm does not result in quantum cutting as the fast nonradiative decay from CTB to 2F5/2 level dominates. These materials are expected to be used as a converting layer for silicon solar cells to enhance their efficiency by splitting each high-energy photon into two NIR photons.

Luminescences from bismuth-doped lime silicate glasses were investigated. Luminescences centered at about 400, 650, and 1300 nm were observed, excited at 280, 532 and 808 nm, respectively. These three luminescence bands arise from three different kinds of bismuth ions in the glasses. The visible luminescences centered at 400 and 650 nm arise from Bi 3+ , and Bi 2+ , respectively. The infrared luminescences cover the wavelength range from 1000 to 1600 nm when exited by an 808 nm laser diode. The full width at half maximum (FWHM) of the infrared luminescences is more than 205 nm. The intensity of the infrared luminescence decreases with the increment in CaO content. We suggest that the infrared luminescences might arise from Bi + . Such broadband luminescences indicate that the glasses may be potential candidate material for

Transparent Ni2+-doped MgO-Al2O3-Ga2O3-SiO2-TiO2 glass ceramics were fabricated. The precipitated nanocrystal phase in the glass ceramics was identified by X-ray diffraction and transmission electron microscope. Broadband near-infrared emission centered at 1220 nm with full width at half maximum of about 240 nm and lifetime of about 250 mu s was observed with 980 nm excitation. The longer wavelength emission compared with Ni2+-doped MgAl2O4 crystal was attributed to the low crystal field occupied by Ni2+ in the glass ceramics. The present Ni2+-doped transparent glass ceramics may have potential applications in broadband optical amplifiers. (c) 2007 Elsevier B.V. All rights reserved.

Vycor glasses impregnated with Tb 3+ and Ce 3+ (or Gd 3+ ) were prepared as vacuum ultraviolet (VUV) and ultraviolet (UV) luminescent materials by adsorption of rare-earth ions into a special porous Vycor glass followed by reduction sintering in a CO atmosphere. In the presence of Ce 3+ (or Gd 3+ ), the Tb 3+ emissions under VUV and UV excitation were significantly enhanced owing to energy transfer from Ce 3+ (or Gd 3+ ) to Tb 3+ . Furthermore, it was found that the intensity of Tb 3+ emissions depended on the solution concentration of Ce 3+ (or Gd 3+ ) ions under the excitation at 160 nm but not at 231 nm. The reason may be due to the direct and indirect excitation of Tb 3+ under UV and VUV lights, respectively.

Transparent Ni2+-doped MgO–Al2O3–SiO2 glass ceramics without and with Ga2O3 were synthetized. The precipitation of spinel nanocrystals, which was identified as solid solutions in the glass ceramics, could be favored by Ga2O3 addition and their sizes were about 7.6 nm in diameter. The luminescent intensity of the Ni2+-doped glass ceramics was largely enhanced by Ga2O3 addition which could mainly be caused by increasing of Ni2+ in the octahedral sites and the reduction of the mean frequency of phonon density of states in the spinel nanocrystals of solid solutions. The full width at half maximum (FWHM) of emissions for the glass ceramics with different Ga2O3 content was all more than 200 nm. The emission lifetime increased with the Ga2O3 content and the longest lifetime is about 250 μs. The Ni2+-doped transparent glass ceramics with Ga2O3 addition have potential application as broadband optical amplifier and laser materials.

We report femtosecond laser induced valence state and refractive index change in transparent Sin(3+)-doped fluoroaluminate glass. The effect of annealing on the induced changes was studied and the thermal stability of these changes was discussed. The results show that the femtosecond laser induced valence state change is more stable than the induced refractive index change. The observed phenomenon could be applied to design the thermally erasable or stable storage medium. (c) 2007 Elsevier B.V. All rights reserved.

New broadband near infrared luminescence covering the whole work windows (1260-1625 nm) of the current wavelength division multiplexing (WDM) system was found from bismuth-activated M2O-Al2O3-SiO2 (M = Li, Na) and Li2O-Ta2O5-SiO2 glasses at room temperature in the case of 808 nm-laser excitation. But the near infrared luminescence mechanism of the bismuth-activated glasses is not well understood up to now. The figure-of-merits of bandwidth and gain of the glasses are better than those of Er3+-doped silicate glasses and Ti3+ doped sapphire, implying they are the promising gain-medium candidates for the broadband amplifiers and the widely tunable laser sources. (c) 2007 Elsevier B.V. All rights reserved.

Cladding band structure of air-guiding photonic crystal fibers with high air-filling fraction is calculated in terms of fiber shape variation. The fundamental photonic band gap dependence on structure parameters, air-filling fraction and spacing, is also investigated. The numerical results show that the band gap edges shift toward longer wavelength as the air-filling fraction is increased, whereas the relative band gap width increases linearly. For a fixed air-filling fraction, the band gap edges with respect to spacing keep constant. With this method, the simulation results agree well with the reported data.

Yb-doped and Yb–Al-codoped high silica glasses have been prepared by sintering nanoporous glasses. The absorption, fluorescent spectra and fluorescent lifetimes have been measured and the emission cross-section and minimum pump intensities were calculated. Codoping aluminum ions enhanced the fluorescence intensity of Yb-doped high silica glass obviously. The emission cross-sections of Yb-doped and Yb–Al-codoped high silica glasses were 0.65 and 0.82 pm2, respectively. The results show that Yb–Al-codoped high silica glass has better spectroscopic properties for a laser material. The study of high silica glass doped with ytterbium is helpful for its application in Yb laser systems, especially for high-power and high-repetition lasers.

Broadband near-infrared (IR) luminescence in transparent alkali gallium silicate glass-ceramics containing Ni2+-doped β-Ga2O3 nanocrystals was observed. This broadband emission could be attributed to the 3T2g (3F) → 3A2g (3F) transition of octahedral Ni2+ ions in glass-ceramics. The full width at half-maximum (FWHM) of the near-IR luminescence and fluorescent lifetime of the glass-ceramic doped with 0.10 mol% NiO were 260 nm and ∼1220 μs, respectively. It is expected that transparent Ni2+-doped β-Ga2O3 glass-ceramics with this broad near-IR emission and long fluorescent lifetime have potential applications as super-broadband optical amplification media.

Infrared (IR) luminescence covering 1.1 to ∼1.6 μm wavelength region was observed from bismuth-doped barium silicate glasses, excited by a laser diode at 808 nm wavelength region, at room temperature. The peak of the IR luminescence appears at 1325 nm. A full width half-maximum (FWHM) and the lifetime of the fluorescence is more than 200 nm and 400 μs, respectively. The fluorescence intensity increases with Al2O3 content, but decreases with BaO content. We suggest that the IR luminescence should be ascribed to the low valence state of bismuth Bi2+ or Bi+, and Al3+ ions play an indirect dispersing role for the infrared luminescent centers.

We report on ultrabroad infrared (IR) luminescences covering the 1000–1700-nm wavelength region, from Bi-doped 75GeO2–20RO–5Al2O3–1Bi2O3(R = Sr, Ca, and Mg) glasses. The full width at half-maximum of the IR luminescences excited at 980 nm increases (315 → 440 → 510 nm) with the change of alkaline earth metal (Mg2+→ Ca2+→ Sr2+). The fluorescence lifetime of the glass samples is 1725, 157, and 264 μs when R is Sr, Ca, and Mg, respectively. These materials may be promising candidates for broad-band fiber amplifiers and tunable laser resources.

Nd3+-codoped and Al3+-Nd3+-codoped high silica glasses have been prepared by sintering nanoporous glasses impregnated with Nd3+ and Al3+ ions. The Judd–Ofelt intensity parameters Ω2,4,6 of Nd3+-doped high silica glasses were obtained and used to analyze aluminum codoping effects. Fluorescence properties of Nd3+-doped high silica glasses strongly depend on the Al3+ concentration. While Nd3+ ion absorption and emission intensities of obviously increase when aluminum is added to Nd3+-doped high silica glasses, fluorescence lifetimes decrease and aluminum codoping has almost no influence on the radiative quantum efficiencies. This indicates that aluminum codoping is responsible for an anti-quenching effect through a local modification of rare-earth environments rather than through physical cluster dispersion.

We report a method for the selective introduction of fluorescent Ag nanoclusters in glass. Extinction and photoluminescence spectra show that a fraction of the Ag atoms are generated through femtosecond laser induced multiphoton reduction and then aggregate to form Ag nanoclusters after heat treatment. Red luminescence from the irradiated region is observed under blue or green laser excitation. The fluorescence can be attributed to interband transitions within Ag nanoclusters. This method provides a novel route to fabricate fluorescent nanomaterials in 3D transparent materials. (c) 2007 Elsevier B.V. All rights reserved.

We report ultrabroad infrared luminescence from Bi-doped aluminogermanate glasses. The infrared luminescence almost covers the whole low loss wavelength region (1200–1650 nm) of silica glass fiber when excited by a diode laser at 980 nm. The full width at half maximum (FWHM) of the luminescence is 510 nm. The luminescence peak can be divided into three Gaussian peaks, and the fluorescence lifetime of the three emissions are 297 μs, 470 μs and 1725 μs, respectively. These fluorescence properties indicate that the glasses are promising material for broadband optical amplifiers.

Broadband infrared luminescence covering the optical telecommunication wavelength region of O, E and S bands was observed from bismuth-doped zinc aluminosilicate glasses and glass-ceramics. The spectroscopic properties of the glasses and glass-ceramics depend on the thermal-treatment history. With the appearance of gahnite (ZnAl2O4) crystalline phase, the fluorescent peak moves to longer wavelength, but the fluorescent intensity decreases. The ∼1300 nm fluorescence with a FWHM larger than 250 nm and a lifetime longer than 600 μs possesses these optical materials with potential applications in laser devices and broadband amplifiers. The broad infrared luminescence from the bismuth-doped zinc aluminosilicate glasses and glass-ceramics might be from BiO or bismuth clusters rather than from Bi5+ and Bi3+.

Sensitive and specific analysis of microRNAs (miRNAs) in a single tube without the need of thermal cycler instrument would greatly facilitate the investigation of miRNA-associated regulatory circuits and diseases. Homogeneous isothermal amplification assays are attractive in conducting single tube assays that can minimize contamination-prone steps and simplifies assay procedures. However, the relative low amplification efficiency and high detection background remain as bottlenecks restricting their more versatile applications. In this work, we have developed a novel isothermal exponential enzymatic amplification (IEEA) strategy for miRNAs analysis. By rational triple cascade amplification cycles of target recycling, nicking-replication reaction, and DNAzyme catalysis, the strategy exhibited high signal amplification efficiency (10(4)-10(9) folds of amplification in 1h) with very low detection background and excellent specificity. As a result, the miR-27a target model was rapidly determined with a limit of detection down to 0.79 aM (S/N=3), corresponding to 94 copies of the miRNA molecule in a 200 μL sample solution. The levels of miR-27a in atherosclerotic sprague-dawley rats were accurately quantified. The strategy is anticipated to have an important impact on the development of simple and rapid molecular diagnostic applications for any short oligonucleotides.

To evaluate the efficacy of Yacovino repositioning maneuver in patients with anterior semicircular canal benign paroxysmal positional vertigo (ASC-BPPV).Nine patients were diagnosed as ASC-BPPV from January 2013 to October 2014. All the patients were performed with Yacovino repositioning maneuver and the effective rate were evaluated by Dix-Hallpike tests.Among the nine ASC-BPPV patients, 2 cases were successfully controlled by the first maneuver, 2 cases by the second time, and the nystagmus of 1 case was disappeared after 1 months' follow-up. The remaining 3 cases were respectively followed up till 7,8, 12 months with consistent positional downbeat nystagmus.Being a relative low incidence disease, of ASC-BPPV also has low effective rate after Yacovino repositioning maneuver.

Initiation of flowering, also called heading, in rice (Oryza sativa) is determined by the florigens encoded by Heading date 3a (Hd3a) and RICE FLOWERING LOCUS T1 (RFT1). Early heading date 1 (Ehd1) regulates Hd3a and RFT1. However, different rice varieties have diverged alleles of Ehd1 and Hd3a/RFT1 and their genetic interactions remain largely unclear. Here we generated three segregating populations for different combinations of diverged Ehd1 and Hd3a/RFT1 alleles, and analyzed their genetic interactions between these alleles. We demonstrated that, in an ehd1 mutant background, Hd3a was silenced, but RFT1 was expressed (although at lower levels than in plants with a functional Ehd1) under short-day (SD) and long-day (LD) conditions. We identified a nonfunctional RFT1 allele (rft1); the lines carrying homozygous ehd1 and Hd3a/rft1 failed to induce the floral transition under SD and LD conditions. Like Hd3a, RFT1 also interacted with 14-3-3 proteins, the florigen receptors, but a nonfunctional RFT1 with a crucial E105K mutation failed to interact with 14-3-3 proteins. Furthermore, analyses of sequence variation and geographic distribution suggested that functional RFT1 alleles were selected during rice adaptation to high-latitude regions. Our results demonstrate the important roles of RFT1 in rice flowering and regional adaptation.

We report the near to middle infrared luminescence and energy transfer process of Er3+/Yb3+ co-doped fluorotellurite glasses under 980, 1550 and 800 nm excitations, respectively. Using a 980 nm laser diode pump, enhanced 1.5 and 2.7 μm emissions from Er3+:I13/2→4I15/2 and I11/2→4I13/2 transitions are observed, in which Yb3+ ions can increase pumping efficiency and be used as energy transfer donors. Meanwhile, Yb3+ can also be used as an acceptor and intensive upconversion luminescence of around 1000 nm is achieved from Er3+:I11/2→4I15/2 and Yb3+: F5/2→4F7/2 transitions using 1550 nm excitation. In addition, the luminescence properties and variation trendency by 800 nm excitation is similar to that using 1550 nm excitation. The optimum Er3+ and Yb3+ ion ratio is 1:1.5 and excess Yb3+ ions decrease energy transfer efficiency under the two pumpings. These results indicate that Er3+/Yb3+ co-doped fluorotellurite glasses are potential middle- infrared laser materials and may be used to increase the efficiency of the silicon solar cells.

Single-mode ytterbium-doped phosphate all-solid photonic crystal fiber (AS-PCF) with 13.8 W output power and 32% slope efficiency was reported. By altering the diameter of the rods around the doped core and thus breaking the symmetry of the fiber, a polarization-maintaining AS-PCF with degree of polarization of >85% was also achieved, for the first time to knowledge, in a phosphate PCF.

We design and fabricate an optical fiber doped with amorphous yttrium aluminosilicate (YAS, Y2O3-Al2O3-SiO2) nanoparticles in the core, and investigate its supercontinuum (SC) generation at different pump wavelength.

International audience; Yb3+/Al3+-co-doped silica glasses with different F− content were prepared in this work by sol–gel method combined with high temperature sintering. XRF, FTIR and XPS methods were used to confirm the presence of F−. The effects of F− on the optical and spectroscopic properties of these glasses have been investigated. It is worth to notice that the F−/Si4+ mass ratio equal to 9% is a significant value showing a real change in the variation trends of numerous following parameters: refractive index, UV absorption edge, absorption and emission cross sections, scalar crystal-field NJ and fluorescent lifetimes. Furthermore, introduction of F− can adjust the refractive index of Yb3+/Al3+-co-doped silica glass and it is useful for large mode area (LMA) fibers.

The new progress of sol-gel method combined with high temperature sintering for the preparation of rare earth ion doped silica core glass and large mode area fiber have been proposed.

The characteristics of the cladding band structure of air-core photonic crystal fibers with silica rings in triangular lattice are investigated by using a standard plane wave method. The numerical results show that light can be localized in the air core by the photonic band gaps of the fiber. By increasing the air-filling fraction, the band gap edges of the low frequency photonic band gaps shift to shorter wavelength, whereas the band gap width decreases linearly. In order to make a specified light fall in the low frequency band gaps of the fiber, the interplay of the silica ring spacing and the air-filling fraction is also analyzed. It shows that the silica ring spacing increases monotonously when the air-filling fraction is increased, and the spacing range increases exponentially. This type fiber might have potential in infrared light transmission.

We report on the effect of various alkaline-earth metal oxides on the broadband infrared luminescence covering 1000‐1600 nm wavelength region from bismuth-doped silicate glasses. The full width at half maximum (FWHM) of the infrared luminescence and the fluorescent lifetime is more than 200 nm and 400 µs, respectively. The fluorescent intensity decreases with increasing basicity of host glasses. Besides the broadband infrared luminescence, luminescence centered at 640 nm was also observed, which should be ascribed to Bi 2+ rather than to the familiar Bi 3+ . We suggest that the infrared luminescence should be assigned to the X2 2 3/2 ! X1 2 1/2 transition of BiO molecules dispersed in the host