bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in selenoenzyme genes and prostate cancer risk and survival
Authors: Geybels Milan S. , Hutter Carolyn M. , Kwon Erika M. , Ostrander Elaine A. , Fu Rong , Feng Ziding , Stanford Janet L. , Peters Ulrike 
Published: November 2012

AbstractBACKGROUNDWhile several studies showed that selenium may prevent prostate cancer (PCa), few studies have evaluated variation in selenoenzyme genes in relation to PCa risk and survival.METHODSWe studied common variants in seven selenoenzymes genes in relation to risk of PCa and PCa‐specific mortality (PCSM). In a population‐based case–control study of men of European ancestry (1,309 cases, 1,266 controls), we evaluated 35 common, tagging single nucleotide polymorphisms (SNPs) in GPX1 (n = 2), GPX2 (n = 4), GPX3 (n = 6), GPX4 (n = 6), SEP15 (n = 4), SEPP1 (n = 6), and TXNRD1 (n = 7) in relation to PCa risk, and among cases, associations between these variants and risk of PCSM. We used logistic regression and Cox proportional hazards regression to estimate the relative risk of PCa and PCSM, respectively.RESULTSOf the SNPs examined, only GPX1 rs3448 was associated with overall PCa risk with an odds ratio of 0.62 for TT versus CC (95% confidence interval, 0.44–0.88). SNPs in GPX2, GPX3, GPX4, SEP15, and SEPP1 had different risk estimates for PCa in subgroups based on stage and grade. We observed associations between SNPs in GPX4, and TXNRD1 and risk of PCSM. None of these associations, however, remained significant after adjustment for multiple comparisons.CONCLUSIONSWe found evidence that genetic variation in a subset of selenoenzyme genes may alter risk of PCa and PCSM. These results need validation in additional subsets. Prostate 73: 734–742, 2013. © 2012 Wiley Periodicals, Inc.
Photoconducting nanocomposite films of PbS nanocrystals in insulating polystyrene
Authors: Chaudhuri T. K. , Kothari A. J. , Tiwari D. , Ray A. 
Published: November 2012

AbstractLead sulfide (PbS)/polystyrene (PS) nanocomposite (NCP) thin films have been synthesized from solution by in situ thermolysis. PbS nanocrystals (NCs) are of 3–5 nm size as determined from Transmission Electron Microscope. The films are p‐type with dark conductivity of ∼10−6 S cm−1 and high photoconductivity with linear current–voltage (I–V) characteristics. The electrical properties are explained on the basis of strong interaction between PbS and PS as revealed by infrared spectroscopy and thermogravimetric analysis (TGA). magnified image
Investigation of carbon–silicon Schottky barrier diodes
Authors: Yim Chanyoung , Rezvani Ehsan , Kumar Shishir , McEvoy Niall , Duesberg Georg S. 
Published: November 2012

AbstractThe fabrication of high performance Schottky barrier diodes (SBDs) between silicon and two different types of conductive carbon films is reported. The diodes are fabricated by simply spin coating and annealing of photoresist films (PPF) or by the chemical vapour deposition of pyrolytic carbon (PyC) onto n‐type silicon wafers. After patterning with a metal hardmask and structural transfer a defined diode interface has achieved. The current–voltage characteristics of the SBDs were recorded in ambient. Diode parameters including the ideality factor n, the barrier height φB and the series resistance RS were extracted using an extended thermionic emission theory and the Norde function. The ideality factors were n = 1.25 for the PPF/n‐Si diodes and n = 1.45 for the PyC/n‐Si diodes. The values are close to those of commercial products and therefore, these highly durable and easily fabricated diodes may prove to be commercially viable. Moreover, the diode characteristics can be used to evaluate the electrical properties of thin carbon films.
Resonance behavior of defect‐induced modes in metallic and semiconducting single‐walled carbon nanotubes
Authors: Laudenbach Jan , Hennrich Frank , Kappes Manfred , Maultzsch Janina 
Published: November 2012

AbstractWe analyze the defect‐induced Raman mode (D mode) and the second order 2D mode of samples enriched with metallic and semiconducting single‐walled carbon nanotube (SWCNT). By resonance Raman spectroscopy, we study the evolution of the line shape of the D and 2D mode. We compared the radial‐breathing mode (RBM) frequencies with different components of the D and 2D mode in the enriched samples and a non‐enriched SWCNT reference material. We show that the components of the broad D mode can be assigned to different species of nanotubes and that this assignment is not necessarily correlated to the RBM for the same excitation energy. magnified imageRaman intensity of the 2D mode for differently enriched samples and comparison with a reference sample. The gray spectrum is the sum of the spectra from the enriched samples.
Chirally enhanced solubilization through perylene‐based surfactant
Authors: Ernst Friederike , Heek Timm , Haag Rainer , Reich Stephanie , Setaro Antonio 
Published: November 2012

AbstractRecently we introduced a rationally designed surfactant which forms energy transfer complexes with carbon nanotubes. We investigate the chiral selectivity of this compound, a perylene derived surfactant, through photoluminescence (PL) measurements, and find a strong enhancement of the luminescence intensity for one particular group of chiralities. The effect is striking, with luminescence increases of several hundred percent.Chiral selectivity of the investigated surfactant compound as compared to solubilization through sodium cholate (SC). Small numbers indicate chirality, large numbers laola family. magnified image
Spectroscopic study of the diameter distribution of B‐doped single‐walled carbon nanotubes
Authors: Ruiz‐Soria G. , Daothong S. , Pichler T. , Ayala P. 
Published: November 2012

AbstractIn this paper, we report on the diameter distribution of boron‐doped single‐walled carbon nanotubes grown from triethyl borate with high vacuum chemical vapor deposition, using multi‐frequency Raman resonance spectroscopy. The nanotube yield is higher than in previously reported material produced with the same method. Our results suggest that the amount of as‐grown material and the range of diameters are directly correlated with feedstock used in the synthesis. The ID/IG ratio shows that the morphology of the samples is critically affected by the temperature. The population of diameters in the optimal conditions shows a Poisson distribution with a mean value at ∼1.15 nm.
Magnetic phase transition for defect induced electron spins from fully metal–semiconductor separated SWCNTs
Authors: Havlicek M. , Chernov A. , Jantsch W. , Wilamowski Z. , Yanagi K. , Kataura H. , Rümmeli M. H. , Malissa H. , Kuzmany H. 
Published: November 2012

AbstractESR experiments from PtRhRe grown and highly semiconductor—metal separated single‐walled carbon nanotubes (SWCNTs) were performed at 9.45 GHz and temperatures T between 0.39 and 200 K. No explicit evidence was found for a response from itinerant electrons in the metallic tubes. Rather, in both the metallic (M) and the semiconducting (SC) tubes, the ESR signal originates from quasi‐localized defect spins but interactions with free electrons render the two systems characteristically different. The spin susceptibility was of Curie–Weiss type for T ≥ 10 K. For annealed samples it drops for lower T indicating a transition to a ferromagnetic state. Linewidths decrease and increase with increasing T for M and SC tubes, respectively. As a consequence they cross for the two systems. Interaction of spins with free carriers in M tubes via an RKKY type mechanism and increase of linewidth with temperature for SC tubes due to spin–lattice interaction is suggested to be responsible for this.
Synthesis of novel thiophene‐phenylene oligomer derivatives with a dibenzothiophene‐5,5‐dioxide core for use in organic solar cells
Authors: Fujii Shunjiro , Duan Zongfan , Okukawa Takanori , Yanagi Yuichiro , Yoshida Akira , Tanaka Takeshi , Zhao Gaoyang , Nishioka Yasushiro , Kataura Hiromichi 
Published: November 2012

AbstractA novel donor–acceptor–donor oligomer, 3,7‐bis[5‐(4‐n‐hexylphenyl)‐2‐thienyl]dibenzothiophene‐5,5‐dioxide (37HPTDBTSO) with a dibenzothiophene‐5,5‐dioxide core and end‐cap phenylene–thiophene moieties, was synthesized using Stille cross‐coupling reactions. The functional properties, including the optical and electrochemical properties, were investigated. Using 37HPTDBTSO and phenyl‐C61‐butyric acid methyl ester (PCBM) as a photoactive layer, bulk‐heterojunction solar cell devices were fabricated by a spin‐coating technique. 37HPTDBTSO was found to be a valuable electron donor. The device had a high open circuit voltage of 0.85 V and the highest power conversion efficiency of 0.84% when the weight ratio of 37HPTDBTSO to PCBM was 1:1.5. These results indicate that the new oligomer is a promising solution‐processable photovoltaic material.
Enhanced optical absorbance of CVD‐graphene monolayer by combination with photonic crystal slab
Authors: Rybin Maxim G. , Pozharov Anatoliy S. , Chevalier Céline , Garrigues Michel , Seassal Christian , Peretti Romain , Jamois Cécile , Viktorovitch Pierre , Obraztsova Elena D. 
Published: November 2012

AbstractWe present the fabrication of graphene by chemical vapour deposition (CVD) on nickel foils. The growth process was optimized for formation of large area and high quality graphene monolayer films. The film quality was confirmed by Raman spectroscopy. Although the absorbance of a bare single graphene layer is limited to 2.3%, we show theoretically that it can be enhanced to 50% by integration with a resonant reflective membrane based on one‐dimensional (1D) photonic crystal (PC) slab. The absorbance of a graphene monolayer combined with a PC membrane slab was increased up to 16%, experimentally.
Tunable far‐IR bandgaps in a one‐dimensional graphene‐dielectric photonic crystal
Authors: Hajian Hodjat , Soltani‐Vala Ali , Kalafi Manoochehr 
Published: November 2012

AbstractWe propose a novel type of one‐dimensional photonic crystal composed of stack of alternating layers of dielectric and graphene sheets. Based on discontinuity in derivative of electric field component in the boundaries between graphene sheets and dielectric layers, analytical dispersion relations of this structure, for both TE and TM polarizations, is obtained. A comparison between bandgaps created in this structure and ones created in a one‐dimensional metallic photonic crystal, for normal incidence is made. It is concluded that a novel type of bandgap appears in this structure due to dissipative feature of graphene which we call it graphene absorption bandgap. Moreover, in comparison with the one‐dimensional metallic photonic crystal, the electromagnetic waves penetrate in this structure with much lower damping. Finally, since the chemical potential of graphene sheets can be modified by gate voltage, the bandgaps in the considered structure can be tuned by the gate voltage (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chalcogenide/tellurite hybrid microstructured optical fiber with high nonlinearity and flattened dispersion
Authors: Kawashima Hiroyasu , Kohoutek Tomas , Yan Xin , Suzuki Takenobu , Ohishi Yasutake 
Published: November 2012

AbstractWe have investigated a new design of hybrid microstructured optical fiber (HMOF) with chalcogenide glass core and tellurite glass cladding. We conducted the chromatic dispersion simulation and nonlinear coefficient calculation by using finite element method. The flattened dispersion with value between ‐20 and 32 ps/nm/km were successfully realized in wide wavelengths ranging from 1.5 to 3.8 μm and the nonlinear coefficient was 86000 km‐1W‐1, one or two orders lager than that of the highly nonlinear fibers reported so far. This HMOF exhibited promising features such as the low flattened dispersion property as well as high nonlinearity, which led to broadband optical amplification, wavelength conversion, and supercontinuum generation from near‐ to mid‐infrared region (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication and photoluminescence properties of semiconductor microtubes separated from substrates like bridge structures
Authors: Ito Yuki , Akahane Koichi , Hosoda Makoto , Ohtani Naoki 
Published: November 2012

AbstractWe fabricated semiconductor microtubes separated from substrates and investigated photoluminescence (PL) properties. The rolling of microtubes containing quantum dots (QDs) was found to happen at many points on the surface of the substrate, while the rolling of microtubes containing a quantum well (QW) started from the cleaved surface. The semiconductor microtubes separated from substrates like bridge structures could be successfully fabricated using photolithography and wet‐etching. The distance between the microtube and the substrate was about 30 nm. In this case, lasing oscillations could not be observed due to the large loss of optical power caused by the absorption in the substrate. This indicates that the wider separation between the microtube and the substrate is necessary for achieving the lasing oscillations (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improving the efficiency of red phosphorescent organic light emitting diodes by exciton management
Authors: Chang Yi‐Lu , Puzzo Danny P. , Wang Zhibin , Helander Michael G. , Qiu Jacky , Castrucci Jeffrey , Lu Zheng‐Hong 
Published: November 2012

AbstractPhosphorescent organic light emitting diodes (PHOLEDs) have undergone remarkable development from both academia and industry in the past decade. Nevertheless, devices with higher efficiency remain highly desirable for energy‐efficient general lighting as well as low power consumption LED backlight applications. In this respect, several groups have conducted complex device engineering designs such as doping of the transport layers to increase charge carrier mobility, incorporation of blocking layers to confine excitons/charge carriers, or use of multiple emissive layers to widen the emission zone, in order to achieve higher device performances. In this work, we report an alternative and relatively simple approach to improve the efficiency of red PHOLEDs by exciton management to attain a high external quantum efficiency (EQE) of >20%. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray and photoluminescence properties of Sm3+ doped barium sulfide
Authors: Maeda Kouji , Kawaida Nao , Tsudome Ryutaro , Sakai Kentaro , Ikari Tetsuo 
Published: November 2012

AbstractX‐ray induced luminescence (XL) properties of phosphor materials made of samarium doped barium sulfide have been investigated. The samples were prepared by solid‐phase reaction method heated at 1200 °C for 10 hours from the mixture of barium sulfide (BaS, 99.9%) and samarium sulfide (Sm2S3, 99.9%) in evacuated silica ampoule. The concentration of Sm was from 0 to 5 at.%. The optical characterizations of the samples were carried out by photoluminescence (PL) and XL spectroscopies at room temperature. The red light XL can be visually observed clearly in the dark. The XL spectral bands at 565, 600, and 650 nm bands were identified and attributed to the transitions from 4G5/2 to 6H5/2, 6H7/2, and 6H9/2 in Sm3+ ions respectively. The XL and PL intensity as a function of Sm content have a maximum at 2 at.% followed by a decrease of intensity due to concentration quenching of Sm ions. The spectral shape of XL was similar to 325 nm excited PL and was different to 405 nm PL. The shape of luminescence has an influence on the direct or indirect excitation of rare‐earth ions (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Many‐body effects in optically‐trapped metallic nanoparticles under thermal fluctuations
Authors: Iida Takuya , Tamura Mamoru 
Published: November 2012

AbstractWe have theoretically studied light‐induced many‐body dynamics of metallic nanoparticles (NPs) under the focused laser beam and the thermal fluctuations in liquid medium at room temperature. The effect of surface ionization is also taken into account. The random motion of NPs by collisions of medium molecules can be suppressed with increasing the laser intensity, and the transition from a diffusive state to metastable states of metallic NPs is possible. Obtained results will provide a novel way to control the phase transitions in assembled structure of NPs under the balance of optically‐modulated interparticle forces and thermal fluctuations. Such a mechanism is significantly different from a conventional gas‐liquid‐solid transition based on spontaneous interparticle forces because it is based on the transient anisotropic force controlled by light (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Organic/inorganic hybrid optical upconversion devices for near‐infrared imaging
Authors: Ban Dayan , Chen Jun , Tao Jianchen , Helander Michael G. , Wang Zhibin , Qiu Jacky , Lu Zhenghong 
Published: November 2012

AbstractTraditional near infrared (NIR) imaging is realized by a two dimensional InGaAs photodetector (PD) array integrated with a Si readout integrated circuit active matrix. The integration between the two different semiconductor arrays seriously restrains the device size‐scalability and leads to high manufacture cost. One alternative approach is to up‐convert infrared photons to a shorter wavelength (e.g., 1 µm or below) that can be effectively detected by a conventional Si detector. Herein, we report a highly simplified single‐mesa (pixel‐less) hybrid organic/inorganic up‐conversion imaging device through the integration of a large area inorganic PD with an organic light emitting diode, which can up‐convert a NIR scene to a visible‐light image. By combining the fabricated device with a commercially available camera, we demonstrate the first time pixel‐less up‐conversion NIR imaging with a spatial resolution of better than 6 µm. This device has great potential for making low‐cost, large‐area and high resolution NIR cameras (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical analysis of wavelength conversion through an antenna‐enhanced up‐conversion
Authors: Osaka Yoshiki , Yokoshi Nobuhiko , Nakatani Masatoshi , Ishihara Hajime 
Published: November 2012

AbstractWe theoretically investigate two‐photon up‐conversion process on a quantum dot (QD) through an optical antenna for high efficiency wavelength conversion. For a simplified one‐dimensional model, we analytically derive the propagator for the up‐conversion process, and numerically calculate the wave function of the converted photon. As a result, the up‐conversion probability can be increased up to 0.7. Because the probability for the QD only is about 0.04 in the same condition, one can see that the optical antenna clearly enhances the process. We also find the existence of the optimal regime for the antennaQD coupling constant. We discuss the origin of the optimal coupling and show that a quantum mechanical coupling between the QD and optical antenna plays an essential role for the high efficiency wavelength conversion. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Proposal of composite photonic structure element for efficient terahertz generation
Authors: Oyamada Atsuyuki , Kitaguchi Hisanobu , Ebata Keiji , Ishihara Hajime 
Published: November 2012

AbstractIn this study, we propose new terahertz generation method. When we inject pump and signal wave into periodic multilayer structure obliquely (abstract figure), transmission resonant mode splits into two modes, i.e. p‐polarized mode and s‐polarized mode. By using two modes for difference frequency generation (DFG), THz wave can generate. As a result of theoretical calculation, composite photonic structure shows high performance, i.e. the conversion efficiency up to 10‐3% and wide tuneable frequency ranging from a few hundred of GHz to 3 THz. Further, the thickness of this element is order of a few micrometers that includes resonator mirror parts and total optical system can become compact size. This scheme has potential to achieve tuneable continuous wave (cw) THz source at room temperature. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation of poly(vinylidene difluoride/trifluoroethylene/chlorotrifluoroethylene) terpolymer thin films for dielectric bolometer mode infrared sensors
Authors: Murakami Shuichi , Satoh Kazuo , Uno Mayumi , Sakurai Yoshiaki 
Published: November 2012

AbstractPoly(vinylidene difluoride/trifluoroethylene/chloro‐trifluoroethylene) (P(VDF/TrFE/CTFE)) ferroelectric terpolymer films have been prepared by spin coating by using methyl ethyl ketone solution on Au/Cr/glass sub‐strates. The leakage current for these films is relatively low. Measurements of dielectric properties reveal that in the low frequency regime (<10 Hz) the real and imagi‐nary parts of the relative complex dielectric constant (ε ′‐iε ″) increase with decreasing frequency. This behavior seems to be due to electrode polarization. In the high fre‐quency regime (∼1 kHz), the dielectric loss factor is about 0.06, which is relatively low. The temperature co‐efficient of the dielectric constant (TCD) is as high as 1.3%/K at 25 °C for frequencies of 1, 10, and 100 kHz. The‐se results show that P(VDF/TrFE/CTFE) terpolymer films are promising materials for use in dielectric bolom‐eter mode infrared sensors, which are based on the temperature dependence of the dielectric constant. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
uGaN growth on laser patterned sapphire substrate: quality feature
Authors: Jelmakas Edgaras , Alsys Marius , Gečys Paulius , Dobrovolskas Darius , Kadys Arūnas , Račiukaitis Gediminas , Tomašiūnas Roland 
Published: November 2012

AbstractLaser patterning technique as a flexible tool to grow high quality undoped gallium nitride (uGaN) on sapphire wafers is presented. A series of stripes were formed on sapphire wafer surface using Nd:YAG laser (100 kHz, 266 nm, 30 ps pulse) with variable pulse power (40‐670 mW), laser spot velocity over the wafer (1‐46 mm/s) and distance between the stripes (4‐15 μm). Stripes width was ∼2‐5 μm. After laser patterning sapphire wafers were cleaned using aqua regia and etched using sulphuric and phosphoric acid solution. SEM images after wet chemical etching show less surface roughness and open sapphire crystalline planes compared to surfaces treated with laser. Undoped GaN was grown by metal‐organic chemical vapour deposition (MOCVD). Used III/IV ratio: 2400, reactor pressure: 150 mBar, temperature: 1065 °C. SEM and AFM results show reduction of dislocation density in grown gallium nitride layer. The growing of this layer was performed using epitaxial lateral overgrowth (ELO) method on laser patterned sapphire substrates. Our observation revealed that the optimal laser power for sapphire substrate patterning for ELO GaN growth is 70‐300 mW. Moreover, we demonstrated intermediate GaN lateral growth states. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Operating voltage‐independent white electroluminescence from phosphorescent Ir(III) complexes embedded in poly(N‐vinylcarbazole)
Authors: Sakurai Yoshiaki , Yagi Shigeyuki , Ikawa Shigeru , Asuka Hotaka , Maeda Takeshi , Nakazumi Hiroyuki 
Published: November 2012

AbstractWe fabricated simple polymer light emitting devices (PLEDs) based on a single emitting layer containing a hole‐transporting host polymer, poly(N‐vinylcarbazole), and an electron‐transporting 1,3‐bis[(4‐tert‐butylphenyl)‐1,3,4‐oxadiazolyl]phenylene (OXD‐7), doped with iridium complexes. We obtained a white light emission, those Commission Internationale de l’Eclairage color coordinates are x = 0.36 and y = 0.40, by doping with phosphorescent bis‐cyclometalated iridium (III) complexes, Ir‐1 and Ir‐2. About this PLED, the maximum luminance, the maximum power luminous efficiency, and the maximum external quantum efficiency were 10600 cd m–2, 3.49 lm W–1, and 5.20%, respectively. The white emission from this PLED was stable even when the operating voltage was changed. Furthermore, all performance of PLED using OXD‐7 was good compared with PLED using PBD [2‐(4‐biphenylyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole] by use of Ir‐1 and Ir‐2 (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)