bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypothalamic melanin concentrating hormone neurons communicate the nutrient value of sugar
Authors: Domingos Ana I , Sordillo Aylesse , Dietrich Marcelo O , Liu Zhong-Wu , Tellez Luis A , Vaynshteyn Jake , Ferreira Jozelia G , Ekstrand Mats I , Horvath Tamas L , de Araujo Ivan E , Friedman Jeffrey M
Published: December 2013

Sugars that contain glucose, such as sucrose, are generally preferred to artificial sweeteners owing to their post-ingestive rewarding effect, which elevates striatal dopamine (DA) release. While the post-ingestive rewarding effect, which artificial sweeteners do not have, signals the nutrient value of sugar and influences food preference, the neural circuitry that mediates the rewarding effect of glucose is unknown. In this study, we show that optogenetic activation of melanin-concentrating hormone (MCH) neurons during intake of the artificial sweetener sucralose increases striatal dopamine levels and inverts the normal preference for sucrose vs sucralose. Conversely, animals with ablation of MCH neurons no longer prefer sucrose to sucralose and show reduced striatal DA release upon sucrose ingestion. We further show that MCH neurons project to reward areas and are required for the post-ingestive rewarding effect of sucrose in sweet-blind Trpm5−/− mice. These studies identify an essential component of the neural pathways linking nutrient sensing and food reward.
Targeting the link between late pregnancy and breast cancer
Authors: Chakravarthi Balabhadrapatruni VSK , Varambally Sooryanarayana
Published: December 2013

Why does a first pregnancy after age 35 increase the risk of breast cancer, and what can be done to combat this?
Columnar liquid crystal as a unique ferroelectric liquid crystal
Authors: Araoka Fumito , Takezoe Hideo
Published: December 2013

A recently discovered ferroelectric columnar liquid crystal (LC) is reviewed. Particular attention is paid to differentiate it from conventional ferroelectric LCs such as the smectic-C*-type and bent-core LCs from the symmetry point of view. After reviewing ferroelectric smectic LCs (FSLCs), a ferroelectric columnar LC (FCLC) is introduced as a unique ferroelectric LC. FSLCs have a polarization parallel to the layer plane and have arbitrariness in the polarization direction within the two-dimensional plane. Hence surface constraints are generally indispensable for fixing the polarization direction. In contrast, FCLC has an Ising polarization along the column axis, which is very stable once poling is performed and convertible by applying an opposite electric field. In this sense, FCLC is the first genuine ferroelectric LC. Poling and switching can be achieved using spin-coated FCLC films with an open surface as well as conventional sandwich cells. Hence the FCLCs are more suitable for applications such as piezoelectric devices and ultrahigh-density memory devices, whereas only an application to fast display devices is proposed for FSLCs.
Optimization of photovoltaic device based on poly(3-hexylthiophene):C60 bulk heterojunction composites prepared with halogen-free solvent
Authors: Tada Kazuya
Published: December 2013

The combination of halogen-free solvent and neat fullerene is expected to reduce the economical and environmental costs of polymer photovoltaic devices. Recently, it has been found that a naturally produced solvent, 1,2,4-trimethylbenzene, enables the preparation of bulk heterojunction composites with neat C60. However, the power conversion efficiency (PCE) of such devices reported so far was less than 1%. In this research, the annealing effects on and film thickness dependence of the performance of photovoltaic devices based on a composite consisting of equivalent weights of poly(3-hexylthiophene) and C60 have been studied to improve the device performance. The optimized device showed a PCE of 1.21%, suggesting that neat C60 is a promising candidate electron acceptor material for polymer bulk heterojunction composites for environmentally friendly and cost-effective photovoltaic devices.
Bulk-heterojunction organic photovoltaic devices fabricated using asymmetric soluble anthracene core photoprecursors
Authors: Motoyama Takao , Sugii Shuhei , Ikeda Shinya , Yamaguchi Yuji , Yamada Hiroko , Nakayama Ken-ichi
Published: December 2013

Soluble photoprecursors, 2-(2,2′-bithiophenyl)-5,10-dihydro-5,10-ethanoanthracene-12,13-dione (BTAntDK) and 2,7-bis(thiophen-2-yl)-5,10-dihydro-5,10-ethanoanthracene-12,13-dione (DTAntDK), were applied to solution-processed bulk-heterojuction (BHJ) organic photovoltaic devices composed of 2-(2,2′-bithiophenyl) anthracene (BTAnt) or 2,7-bis(thiophen-2-yl)-anthracene (DTAnt) as donor materials and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) as an acceptor material. The mixed solution of the photoprecursor and PCBM was spin-coated on the substrate and converted to the BHJ film of the parent acene and PCBM upon photoirradiation. BTAntDK has an asymmetric structure that improves the miscibility with PCBM; thus, the BHJ photovoltaic device BTAnt:PCBM showed a higher performance than symmetric DTAnt:PCBM.
Photovoltaic properties of organic solar cell with octafluorophthalocyanine as electron acceptors
Authors: Koshiba Yasuko , Onishi Toshiki , Saeki Hiroyuki , Misaki Masahiro , Ishida Kenji , Ueda Yasukiyo
Published: December 2013

Organic photovoltaic (OPV) cells were fabricated using copper-2,3,9,10,16,17,23,24-octafluorophthalocyanine (F8CuPc) as an electron acceptor. Normal and inverted OPV cells using F8CuPc were showed rectification in dark and photovoltaic characteristics under illumination. The inverted-type cell had good durability. The power conversion efficiency (η) of the inverted-type cell was 0.11%, approximately 6.5 times higher than that of the normal-type cell. The cell using F8CuPc was more stable than that using fullerene in air. These results indicate the possibility of using F8CuPc as an electron acceptor for air-stable OPV cells.
Oriented blend films of poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester fabricated by friction transfer method
Authors: Tanigaki Nobutaka , Ikeo Yasuhiro , Mizokuro Toshiko , Heck Claire , Aota Hiroyuki
Published: December 2013

We have been studying oriented thin films of polymers fabricated by the friction transfer method, which allows a variety of conjugated polymers to be aligned into highly oriented films. However, with this method it is difficult to prepare oriented films from a mixture. In this work we prepared oriented thin films of a mixture of regioregular poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which is a promising combination for application in organic solar cells. We obtained oriented blend films of P3HT and PCBM by the friction transfer method from a solid block prepared from a mixed solution with a weight ratio of 1 : 1. Atomic force microscopy shows that microscale phase separation took place in the blend films. Polarized UV–visible spectra show that the P3HT chains were aligned parallel to the friction direction in the blend films. X-ray diffraction studies suggested that the preferred orientation of P3HT crystallites was the “face-on” orientation in the blend film.
Improving the photovoltaic parameters of organic solar cell using soluble copper phthalocyanine nanoparticles as a buffer layer
Authors: Kumar Palanisamy , Santhakumar Kannappan , Shin Paik-Kyun , Ochiai Shizuyasu
Published: December 2013

We prepared copper phthalocyanine nanoparticles (CuPc-NPs) by a simple solution process, for use as a buffer layer in organic solar cells (OSCs) based on a poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl]/[6,6]-phenyl-C71-butyric acid (PCDTBT/PC71BM) active layer. The optical absorption of such buffer layers was analyzed through UV–visible spectral studies in the wavelength range from 300 to 800 nm. The surface and structure were examined by atomic force microscopy (AFM) and X-ray diffraction (XRD) measurements, respectively. The observed XRD spectra suggested the presence of a stable β-crystallite phase of CuPc-NP films. The effect of the CuPc-NP buffer layer on the photovoltaic parameters was studied. The current density–voltage (J–V) characteristics of photovoltaic cells were measured under 100 mW/cm2 (AM 1.5G). An optimized OSC showed a 5.22% PCE, a 0.465 FF, and a 12.68 mA/cm2
J
sc. The improved interface properties and good charge transport properties when using the CuPc-NP layer are believed to be the reasons behind the better device performance.
Electrical properties of bulk-heterojunction organic solar cells with ultrathin titania nanosheet blocking layer
Authors: Itoh Eiji , Maruyama Yasutake , Fukuda Katsutoshi
Published: December 2013

The contributions of ultrathin titanium oxide nanosheet (TN) crystallites to the electrical properties and the diffusion of metal atoms were studied in a bulk-heterojunction (BHJ) cell in indium–tin oxide (ITO)/MoO3/poly(3-hexylthiophene) (P3HT):phenyl-C61-butyric acid methylester (PCBM) active layer/titania nanosheet (TN)/metal multilayered photovoltaic devices. The insertion of only two or three layers of poly(diallyldimethylammonium chloride) (PDDA) and TN multilayered film prepared by the layer-by-layer deposition technique effectively decreased the leakage current and increased the open circuit voltage (V
OC), fill factor (FF), and power conversion efficiency (η) nearly two fold. Although the active layer has a hydrophobic surface, the active layer was fully covered by the insertion of only two or three layers of the PDDA/TN multilayered film and the ultrathin TN layer effectively prevented the metal atoms from diffusing into the polymer film. The impedance analysis and the cross-sectional transmission electron microscopy (TEM) images revealed that the TN layer effectively separated the organic layer/metal interface and blocked holes at the organic/TN interface resulting in the reduction in leakage current by nearly three orders of magnitude and the increase in the capacitance at a voltage around V
OC.
Photocarrier recombination of polymer/fullerene composites in surface-type photocells
Authors: Ito Hiroshi , Tokai Takuya , Suzuki Junya , Tanaka Hisaaki , Kuroda Shin-ichi
Published: December 2013

Carrier recombination kinetics is studied by photocurrent measurements of surface-type photocells of polymer/fullerene composites. A quadrimolecular recombination (QR) in the time range of 0.1 to 100 s, which was found for regioregular poly(3-hexylthiophene), is observed in another semicrystalline polymer, poly{2,5-bis(3-alkylthiophene-2-yl)thieno[3,2-b]thiophene} (PBTTT). By measuring photocurrent and transistor action in the same device, suppression of the recombination in the ambipolar region at a high fullerene content is demonstrated. No QR but bimolecular recombination is observed in cells using amorphous-like poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). These results provide further support that the QR is characteristic of high-mobility semicrystalline polymers in which doubly charged states are formed owing to the lamellar structure.
Open-circuit voltage of ternary blend polymer solar cells
Authors: Xu Huajun , Ohkita Hideo , Benten Hiroaki , Ito Shinzaburo
Published: December 2013

We have studied the different dependence of open-circuit voltage (V
OC) on blend compositions in ternary blend solar cells based on poly(3-hexylthiophene) (P3HT) and the other two materials selected from phenyl-C61-butyric acid methyl ester (PCBM), indene-C60 bisadduct (ICBA), and silicon phthalocyanine bis(trihexylsilyl oxide) (SiPc). For P3HT/PCBM/ICBA ternary blend solar cells, the V
OC monotonically increased with increasing ICBA fraction as reported previously. On the other hand, the V
OC in P3HT/ICBA/SiPc solar cells slightly decreased from 0.84 to 0.82 V at a SiPc fraction of 5% and then was kept constant independently of the SiPc fraction up to 50%. For P3HT/PCBM/SiPc solar cells, the V
OC was almost independent of the SiPc fraction up to 45%, and then abruptly increased from ∼0.55 to 0.82 V at a SiPc fraction of 50%. We discuss these different compositional dependences of V
OC in terms of the energetics and the blend morphology in ternary blend solar cells.
Excited-state dynamics in diketopyrrolopyrrole-based copolymer for organic photovoltaics investigated by transient optical spectroscopy
Authors: Matsuzaki Hiroyuki , Furube Akihiro , Katoh Ryuzi , Singh Samarendra Pratap , Sonar Prashant , Williams Evan Laurence , Vijila Chellappan , Subramanian Gomathy Sandhya , Gorelik Sergey , Hobley Jonathan
Published: December 2013

We investigate the photoexcited state dynamics in a donor–acceptor copolymer, poly{3,6-dithiophene-2-yl-2,5-di(2-octyldodecyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-naphthalene} (pDPP-TNT), by picosecond fluorescence and femtosecond transient absorption spectroscopies. Time-resolved fluorescence lifetime measurements of pDPP-TNT thin films reveal that the lifetime of the singlet excited state is 185 ± 5 ps and that singlet–singlet annihilation occurs at excitation photon densities above 6 × 1017 photons/cm3. From the results of singlet–singlet annihilation analysis, we estimate that the single-singlet annihilation rate constant is (6.0 ± 0.2) × 10−9 cm3 s−1 and the singlet diffusion length is ~7 nm. From the comparison of femtosecond transient absorption measurements and picosecond fluorescence measurements, it is found that the time profile of the photobleaching signal in the charge-transfer (CT) absorption band coincides with that of the fluorescence intensity and there is no indication of long-lived species, which clearly suggests that charged species, such as polaron pairs and triplet excitons, are not effectively photogenerated in the neat pDPP-TNT polymer.
Efficiency limit analysis of organic solar cells: model simulation based on vanadyl phthalocyanine/C60 planar junction cell
Authors: Miyadera Tetsuhiko , Wang Zhiping , Yamanari Toshihiro , Matsubara Koji , Yoshida Yuji
Published: December 2013

The power-conversion-efficiency (PCE) limit was simulated for a planar vanadyl phthalocyanine (VOPc)/C60 heterojunction model device. On the basis of the transfer matrix method and exciton diffusion analysis, short-circuit current density (J
sc) was simulated as a function of exciton diffusion length (L
d). The model device was simulated to be operated in a wide wavelength range (300–950 nm). A large J
sc up to 30 mA/cm2 was obtained at an L
d of approximately 10 µm. On the basis of the estimated V
oc values of 0.8–1.0 V, the PCE limit of the model device was calculated to be in the range of 17–22%, which is close to the reported results of thermodynamic analysis.
Improved performance of hybrid ZnO/polymer solar cell via construction of hierarchical nanostructures and surface modification of ZnO
Authors: Ruankham Pipat , Yoshikawa Susumu , Sagawa Takashi
Published: December 2013

Photovoltaic performance of hybrid ZnO/polymer solar cell is enhanced through the addition of ZnO nanoparticles (NPs) onto ZnO nanorod arrays (NRs), and surface modification with squaraine (Sq). The cluster of NPs at the end of NRs is formed during spin coating process but poly(3-hexylthiophene) (P3HT), as electron donor, is able to infiltrate into the rod-to-rod space, as confirmed by zero-loss energy-filtered transmission electron microscopy (zero-loss EFTEM) observation. Due to the increase in ZnO/P3HT interface area, the NP-coated NR device shows power conversion efficiency (PCE) of 0.49%, which is higher than that of the pristine ZnO NRs/P3HT one (0.26%). Further improvement is achieved by the adsorption of Sq onto the NP-coated ZnO NR surfaces. After the dye-modification, the P3HT infiltration is poorer than the unmodified one. This leads to the ZnO NRs/Sq/air interface, where exciton separation does not occur. However, due to the large surface area of NPs and the light absorption in near IR region of Sq, the PCE increased to 1.37% with relatively higher short circuit current density as compared with the case without the NPs and Sq.
Characterization of aryl-functionalized 2,4,6-tris(2-thienyl)-1,3,5-triazine thin films and their application to organic field-effect transistors
Authors: Hosokai Takuya , Muraoka Hiroki , Mori Masayoshi , Kurihara Ryota , Ogawa Satoshi , Yoshimoto Noriyuki
Published: December 2013

Aryl-functionalized 2,4,6-tris(2-thienyl)-1,3,5-triazine derivatives were applied as thin films via thermal vacuum deposition to investigate properties and potential of the thin films for use as active layers in organic field-effect transistors. All derivatives deposited on quartz substrates produced amorphous films. Ultraviolet–visible absorption spectra of the films resemble those of the molecules in solution, and fluorescence spectra depend largely on the aryl groups. When used in organic field-effect transistors, only the N,N-dibutylamino derivative could display the appropriate device characteristics under p-type operation, but it showed low mobility of charge carriers. The origin of the low mobility is discussed in terms of the electronic structure and film structure of the derivatives in the devices.
Annealing effect on light-emitting FET characteristics of π-conjugated liquid crystalline polymer
Authors: Muneishi Tatsuya , Ishizumi Atsushi , Yanagi Hisao
Published: December 2013

Thermal annealing effects on organic light-emitting field-effect transistor (OLEFET) characteristics of a liquid crystalline π-conjugated polymer were investigated using spin-coated films of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophenione] (F8T2). Well-balanced ambipolar carrier injection was attained in the homogeneous polycrystalline film grown from the isotropic phase at 350 °C, resulting in the highest light emission under AC-gate operation. On the other hand, the film with microcrystalline grains quenched from the nematic phase at 290 °C was less electron-transporting so that the light emission intensity was lower than the amorphous film annealed at 250 °C.
Polarized electroluminescent devices based on ultrathin α-sexithiophene on oriented β-phase polyfluorene films
Authors: Heck Claire , Matsumoto Takuya , Mizokuro Toshiko , Aota Hiroyuki , Tanigaki Nobutaka
Published: December 2013

White polarized light emitting devices are produced by combining oriented β-phase polyfluorene (PFO) films with α-sexithiophene (6T) on top. Highly oriented PFO films are fabricated with the friction transfer method and exposed to toluene to partially change their conformation to the metastable β-phase PFO without loss of orientation. Orange emitting 6T is then deposited by the conventional vacuum deposition method on top of the blue emitting oriented PFO films. We studied the effects of 6T thickness on the emission color and the results indicated that whitening is possible by depositing 6T at a thickness of 1.5 nm on β-phase PFO. High polarization of both PFO and 6T emitting regions in the electroluminescence spectra suggested that 6T molecules are oriented parallel to the PFO molecules.
Wavelength dependence and multiple-induced states in photoresponses of copper phthalocyanine-doped gold nanoparticle single-electron device
Authors: Yamamoto Makoto , Ueda Rieko , Terui Toshifumi , Imazu Keisuke , Tamada Kaoru , Sakano Takeshi , Matsuda Kenji , Ishii Hisao , Noguchi Yutaka
Published: December 2013

We have proposed a gold nanoparticle (GNP)-based single-electron transistor (SET) doped with a dye molecule, where the molecule works as a photoresponsive floating gate. Here, we examined the source–drain current (

) at a constant drain voltage under light irradiation with various wavelengths ranging from 400 to 700 nm. Current change was enhanced at the wavelengths of 600 and 700 nm, corresponding to the optical absorption band of the doped molecule (copper phthalocyanine: CuPc). Moreover, several peaks appear in the histograms of

during light irradiation, indicating that multiple discrete states were induced in the device. The results suggest that the current change was initiated by the light absorption of CuPc and multiple CuPc molecules near the GNP working as a floating gate. Molecular doping can activate advanced device functions in GNP-based SETs.
Double-layered thin collector in n-type metal-base organic transistors
Authors: Ueno Yohei , Yashima Tomoyasu , Hirata Naoki , Oguma Naomi , Kido Junji , Nakayama Ken-ichi
Published: December 2013

A very short channel length was achieved in vertical-type metal-base organic transistors using a double-layered collector composed of N,N′-dimethyl-3,4,9,10-perylene tetracarboxylic diimide (Me-PTC) and N,N′-distearyl-3,4,9,10-perylene tetracarboxylic diimide (St-PTC). St-PTC showed low electric conductivities, but inserting it at the interface with the collector electrode improved the on/off ratio to 4 × 104 for a total collector thickness of 105 nm. The decrease in the off current was attributed to the low electric conductivity of St-PTC, and the increase in the on current was discussed from the viewpoint of the morphological change of the collector layer.
Crystal structure of oligothiophene thin films characterized by two-dimensional grazing incidence X-ray diffraction
Authors: Watanabe Takeshi , Koganezawa Tomoyuki , Kikuchi Mamoru , Videlot-Ackermann Christine , Ackermann Jörg , Brisset Hugues , Hirosawa Ichiro , Yoshimoto Noriyuki
Published: December 2013

Crystal structure in an highly oriented organic thin film was determined using two dimensional grazing incidence X-ray diffraction (2D-GIXD). α,ω-Hexyl-distyryl-bithiophene (DH-DS2T) was chosen as the material for the structural analysis, because it is a typical organic semiconductor showing a high crystallinity and an ordered layer-growth behavior. A 2D-GIXD pattern over large range of scattering angles was obtained by using high-brightness synchrotron radiation in SPring-8 and high-sensitive 2D X-ray detector (PILATUS 300 K). The analysis of the observed 2D-GIXD pattern was made to clarify that the crystal structure of highly oriented DH-DS2T thin films belongs to a monoclinic unit-cell with a = 0.58 nm, b = 0.78 nm, c = 3.43 nm, and β = 94.3°, and the space group is determined to be P21/a by considering the extinction rule. Furthermore, by fitting the simulated Bragg peak intensities to the experimental data, the molecular structure is determined. In this structure, two molecules are included in the unit cell and they tilt about 25° against substrate normal.
Theoretical prediction of crystal structures of rubrene
Authors: Obata Shigeaki , Miura Toshiaki , Shimoi Yukihiro
Published: December 2013

We theoretically predict crystal structures and molecular arrangements for rubrene molecule using CONFLEX program and compare them with the experimental ones. The most, second-most, and fourth-most stable predicted crystal structures show good agreement with the triclinic, orthorhombic, and monoclinic polymorphs of rubrene, respectively. The change in molecular conformation is also predicted between crystalline and gas phases: the tetracene backbone takes flat conformation in crystalline phase as in the observed structure. Meanwhile, it is twisted in gas phase. The theoretical prediction method used in this work provides the successful results on the determination of the three kinds of crystal structures and molecular arrangements for rubrene molecule.
Determination of the highest occupied molecular orbital energy of pentacene single crystals by ultraviolet photoelectron and photoelectron yield spectroscopies
Authors: Nakayama Yasuo , Uragami Yuki , Yamamoto Masayuki , Machida Shin’ichi , Kinjo Hiroumi , Mase Kazuhiko , Koswattage Kaveenga Rasika , Ishii Hisao
Published: December 2013

The electronic structures of pentacene single crystals (SCs) were elucidated by ultraviolet photoelectron spectroscopy (UPS) and photoelectron yield spectroscopy (PYS). An asymmetric HOMO peak profile of the pentacene SCs obtained by UPS exhibits a close similarity to the k-projected density-of-states of the valence band that has been predicted by a theoretical calculation [H. Yoshida and N. Sato, Phys. Rev. B 77, 235205 (2008)]. The ionization energy of the pentacene SCs is successfully determined to be 4.95 (± 0.03) eV which is evidently greater than that of the bulk films of pentacene [4.90 (± 0.02) eV].
Evaluation of thermal stability of electro-optic polymer by thermally stimulated depolarization current measurement
Authors: Mo Xuepeng , Kinemura Kazuhiko , Yamada Toshiki , Otomo Akira , Taguchi Dai , Manaka Takaaki , Iwamoto Mitsumasa
Published: December 2013

The thermal relaxation process of electro-optic (EO) polymers, Disperse Red 1 (DR1)/poly(methyl methacrylate) (PMMA) guest/host polymer and side-chain copolymer DR1–PMMA (PMMA-co-DR1), was studied using thermally stimulated depolarization current (TSDC) measurement. For the guest/host polymer, two TSDC peaks were identified at temperatures of −50 °C (β-peak) and around 100 °C (α-peak) due to dipolar depolarization. It was also suggested that the α-peak is ascribed to disordering of guest DR1 molecules together with randomization of the main body of the PMMA. For the side-chain copolymer, a simple relaxation process of the side-chain DR1 was observed in contrast with the guest/host polymer. Analyzing the TSDC, we estimated the activation energy and relaxation times, and discussed the relaxation mechanisms. Results showed that the TSDC method is available for evaluating the thermal stability of EO polymer.
Processing condition dependence of time-resolved photoluminescence in thiophene/phenylene co-oligomer microcavities
Authors: Sasaki Fumio , Mochizuki Hiroyuki , Haraichi Satoshi , Yanagi Hisao , Yamao Takeshi , Hotta Shu
Published: December 2013

The fluorescence lifetimes of thiophene/phenylene co-oligomer crystalline films were measured before and after microcavity fabrication processes. We found that the lifetime of the microcavity part was much shorter than that of the nonprocessed part in a previously reported fabrication process. It is suggested that some parts of the fabrication process induce damage to the cavity parts, leading to increased nonradiative recombination processes. As a result, the fluorescence yield decreases and lifetime shortening occurs. We show that the lifetime shortening originates from the metal removal dry etching process, but does not originate from the dry etching process of the organic layers itself. This indicates that the O2-dry etching process is an effective fabrication method for organic laser cavities.
Spectrally narrowed emissions from organic crystals mounted on transfer-printed parylene diffraction gratings
Authors: Fukaya Yoshihide , Obama Yuki , Hotta Shu , Yamao Takeshi
Published: December 2013

We have fabricated diffraction gratings of parylene by evaporation polymerization. The parylene film was deposited onto a commercially available diffraction grating used as a template and transfer-printed onto a substrate. A well-defined periodic structure was replicated on the parylene film surface and its period was in good agreement with that of the template. For future light-emitting device application, we laminated a parylene grating with organic semiconductor crystals and investigated their emission properties under weak ultraviolet light excitation. We observed emissions parallel to the grating wave vector. Their spectra narrowed as peaks with full-widths at half-maxima less than 5 nm. We discussed these narrow emission lines considering them as the propagating light in a waveguide composed of the organic crystal and parylene grating. The present results reflect the formation of a high-quality optical cavity on a parylene film.
Second-order nonlinear optical susceptibilities in nonelectrically poled guest–host polymers with tricyanofuran chromophores
Authors: Ito Kazuma , Sato Yasuaki , Takasu Ryosuke , Mase Nobuyuki , Kawata Yoshimasa , Tasaka Shigeru , Sugita Atsushi
Published: December 2013

In this manuscript, we describe the current manuscript describes the second-order nonlinear optical susceptibility of guest–host polymers possessing chromophores with strongly electron-accepting tricyanofuran (TCF). Chromophores substituted with different numbers of hydroxyl groups were prepared. Our experimental results demonstrated that the guest–host polymers exhibited nonlinear optical susceptibilities simply upon annealing at temperatures higher than the glass transition point of the host polymers even in the absence of applied external DC electric fields. Nonelectrical poling behaviors were only available for the materials possessing hydroxyl-group-functionalized chromophores. The results indicate that chemisorption of the hydroxyl groups on the substrate led to the orientation order of the guest chromophores. The orientation order of the chromophores was reproduced well by the model of poled polymers in previous studies.
Optical properties of broad stopband of a chiral smectic liquid crystal at highly oblique incidence
Authors: Ozaki Ryotaro , Kadowaki Kazunori , Moritake Hiroshi
Published: December 2013

The optical properties of stopbands of a ferroelectric liquid crystal (FLC) in a chiral smectic C phase are investigated experimentally and theoretically. Chiral smectic and cholesteric liquid crystals are regarded as pseudo photonic crystals. They exhibit Bragg reflections corresponding to half- and full-pitch bands. The characteristics of the Bragg reflections at oblique incidence are discussed on the basis of numerical calculations. The full-pitch band of an FLC becomes deeper and wider at highly oblique incidence. Using this characteristic, we demonstrated an FLC stopband with independently tunable wavelength and bandwidth by controlling the temperature and incident angle, respectively.
Optical tuning of extraordinary optical transmission through a metallic hole array using azobenzene dye-doped nematic liquid crystal
Authors: Kobashi Junji , Yoshida Hiroyuki , Matsui Takayuki , Miura Atsushi , Ikeda Naoki , Sugimoto Yoshimasa , Fujikawa Hisayoshi , Ozaki Masanori
Published: December 2013

Optical tuning of extraordinary optical transmission (EOT) through a metallic hole array is achieved using an azobenzene dye-doped nematic liquid crystal. The liquid crystal is aligned homeotropically on the hole array and is sandwiched by a counter substrate placed at a distance of approximately 1 µm from the hole array. Upon UV irradiation, the azobenzene dye photo-isomerizes from the trans conformation to the cis conformation and disturbs the liquid crystalline order, causing a decrease in the effective refractive index. The tuning range achieved was 80 nm, and corresponded to a refractive index shift of 0.086. Optical tuning of EOT properties is potentially important for future all-optical processing of signals.
Director orientation of nematic liquid crystal using orientated nanofibers obtained by electrospinning
Authors: Toan Duong Quoc , Ozaki Ryotaro , Moritake Hiroshi
Published: December 2013

Nanofibers with diameters less than 1000 nm assembled by electrospinning and with a large surface area per unit mass have been attracting considerable attention and are expected to affect the orientation of liquid crystals (LCs). Firstly, to determine the orientated nanofibers on an indium–tin-oxide (ITO) glass surface, the spectral analysis technique of using fast Fourier transform is applied. Optical observation is performed to confirm the orientation of LC molecules in a twisted nematic LC cell. Finally, optical measurement of an LC cell is carried out to estimate the threshold voltage of the LC in two types of twisted nematic LC cell: one with rubbed polyimide and the other with orientated nanofibers as the alignment layer. A twisted nematic LC is oriented in the cell using orientated nanofibers as the alignment layer and the threshold voltage of this cell agrees with that of the conventional polyimide rubbed cell.
Coherent random laser fluid of nematic liquid crystal emulsions
Authors: Nagai Yusuke , Fujimura Ryushi , Kajikawa Kotaro
Published: December 2013

Reported here is a coherent (resonant) random laser fluid of nematic liquid crystal (LC) emulsions. It is a low-viscosity fluid like a usual liquid. The coherent laser is developed because of the high LC droplet density (about 32%) and the high refractive index of the LC. The optical loop forms among the LC droplets and its length is evaluated to be approximately 150 µm. The LC emulsion is useful for the investigation of the mechanism of the random laser because it is a fluid and can easily be used to change the scatterer density.
Electrical properties of ferroelectric liquid crystals during thermal phase transition
Authors: Morimoto Masahiro , Sakaki Yosuke , Koshiba Yasuko , Misaki Masahiro , Ueda Yasukiyo , Ishida Kenji
Published: December 2013

The ferroelectric properties of ferroelectric liquid crystals (FLCs) during thermal phase transition in the surface-stabilized ferroelectric liquid crystal (SSFLC) cells were examined. The coercive electric field (E
c) and remanent polarization (P
r) changed with increasing temperature. These temperature-dependent variations of E
c and P
r were in agreement with the differential scanning calorimetry results. Moreover, the fatigue characteristic of the SSFLC cells was examined. No polarized fatigue was observed after 1 × 106 cycles of polarization switching, because FLCs may have the self-repair property for structural and interfacial defects.
Fabrication of a gel-supported lipid membrane array on a silicon substrate
Authors: Tanaka Aya , Nakashima Hiroshi , Kashimura Yoshiaki , Sumitomo Koji
Published: December 2013

We successfully sealed a gel-confined microwell array on a Si substrate with a lipid membrane by rupturing giant unilamellar vesicles. Atomic force microscope measurements suggested that gel with a hillock structure supported lipid membranes gently because of its soft and elastic properties and improved the stability of the lipid membrane over the microwell array. We found that the lipid membrane sealed the gel-confined microwells and no Ca2+ leakage through the lipid membrane was observed within the detection range of our calcium indicator. We expect that gel with properties similar to cytoplasm consisting of a cytoskeletal network is a potential candidate for providing lipid membranes with mechanical support. This study proposes an artificial cell array system for fluorescence and atomic force microscope observations of functional membrane proteins on silicon-based nanobiodevices.
Decadal sea‐level variability along the coast of Japan in response to ocean circulation changes
Authors: Sasaki Yoshi N. , Minobe Shoshiro , Miura Yuji
Published: December 2013

Decadal sea‐level variability along the coast of Japan and its relation to large‐scale ocean circulation changes from 1993 to 2010 was investigated using tide‐gauge and satellite‐derived sea‐level data. A singular value decomposition (SVD) analysis is performed between coastal sea levels of Japan and sea levels in the western North Pacific. The first SVD mode reveals that the northward shifts of the Kuroshio Extension (KE) jet and the Kuroshio southeast of Japan accompany the coastal sea‐level rise in the early 2000s and 2010, and their southward shifts accompany the coastal sea‐level fall in the late 1990s and the late 2000s. The shifts of the KE jet are induced by westward propagating Rossby wave from the eastern North Pacific, which is concentrated along the KE jet axis as jet‐trapped Rossby waves. The resulting sea‐level changes along the coast of Japan show a strong spatial contrast. The sea‐level fluctuation is quite large along the southeastern coast of Japan that is under the direct influence of the jet‐trapped Rossby waves, and also large in the western coast of Japan, probably due to coastal waves that are excited by the incoming Rossby waves, but is small north of the KE jet latitude. Hence, the nature of the wave trapped by the KE jet produces an “active zone” and a “shadow zone” of coastal sea‐level variability of Japan. Our results indicate that the correct representation of western boundary currents is necessary for reliable prediction of future coastal sea‐level changes.
The effect of a concentration‐dependent viscosity on particle transport in a channel flow with porous walls
Authors: Herterich James G. , Griffiths Ian M. , Vella Dominic , Field Robert W.
Published: December 2013

The transport of a dilute suspension of particles through a channel with porous walls, accounting for the concentration dependence of the viscosity, is analyzed. In particular, we study two cases of fluid permeation through the porous channel walls: (1) at a constant flux and (2) dependent on the pressure drop across the wall. We also consider the effect of mixing the suspension first compared with point injection by considering inlet concentration distributions of different widths. We find that a pessimal inlet distribution width exists that maximizes the required hydrodynamic pressure for a constant fluid influx. The effect of an external hydrodynamic pressure, to compensate for the reduced transmembrane pressure difference due to osmotic pressure, is investigated. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1891–1904, 2014
Occupational health disparities: A state public health‐based approach
Authors: Stanbury Martha , Rosenman Kenneth D.
Published: December 2013

Background

This report used employment and public health surveillance data in Michigan to characterize work‐related race/ethnic health disparities.

Methods

U.S. Census data were used to calculate the percent by race/Hispanic ethnicity in occupational groups ranked by three measures for potential work‐related health risks. Disparities by race/ethnicity were generated from occupational health surveillance data.

Results

Blacks and Hispanics were over‐represented in lower wage–higher manual–labor occupations and in highest risk occupations. Blacks were at greater risk of silicosis, work‐related asthma, and work‐related burns than whites, and Hispanics had higher rates of work‐related acute fatal injuries and pesticide injury than non‐Hispanics.

Conclusions

Michigan employment data indicated that blacks and Hispanics were overly represented in lower paid and more hazardous jobs. Occupational health surveillance data confirmed disparate risks for some illnesses and injuries. This approach can be used in other states to bring awareness to policy makers and direct interventions. Am. J. Ind. Med. 57:596–604, 2014. © 2013 Wiley Periodicals, Inc.
Adult lipids associated with early life growth in traditional melanesian societies undergoing rapid modernization: A longitudinal study of the mid‐20th century
Authors: Weitz Charles A. , Friedlaender Françoise Y. , Friedlaender Jonathan S.
Published: December 2013

Both poor fetal development and accelerated post‐natal growth have been linked to adult dyslipidemias in many studies conducted in developed societies. It is not known, however, whether these relationships only characterize populations with typical Western diets or if they also may develop in groups at the early stages of a dietary transition. Our longitudinal study of traditional rural populations in the Southwest Pacific during a period of extremely rapid modernization in diet and life‐styles shows a nascent association between child growth retardation, subsequent growth acceleration, and adult lipid values in spite of a continuing prevalence of very low lipid levels. However, our results do not entirely conform to results from populations with “modern” diets. Outcome (i.e., young adult) cholesterol and triglyceride levels are more consistently related to initial measures of body fat and growth in body fat measures than with stature, while outcome apo A‐1 is more consistently related to initial stature or stature growth than to measures of body fat. We suggest this may reflect a pattern characteristic of the initial stages of “modernization” associated with dietary change, with stronger and more pervasive relationships emerging only later as populations complete the dietary transition. Am J Phys Anthropol 153:551–558, 2014. © 2013 Wiley Periodicals, Inc.
Evaluation of large‐scale genetic structure in complex demographic and historical scenarios: The mitochondrial DNA and Y‐chromosome pools of the Iberian Atlantic façade
Authors: Pardiñas Antonio F. , Roca Agustín , García‐Vazquez Eva , López Belén
Published: December 2013

Genetic structural patterns of human populations are usually a combination of long‐term evolutionary forces and short‐term social, cultural, and demographic processes. Recently, using mitochondrial DNA and Y‐chromosome loci, various studies in northern Spain have found evidence that the geographical distribution of Iron Age tribal peoples might have influenced current patterns of genetic structuring in several autochthonous populations. Using the wealth of data that are currently available from the whole territory of the Iberian Peninsula, we have evaluated its genetic structuring in the spatial scale of the Atlantic façade. Hierarchical tree modeling procedures, combined with a classic analysis of molecular variance (AMOVA), were used to model known sociocultural divisions from the third century BCE to the eighth century CE, contrasting them with uniparental marker data. Our results show that, while mountainous and abrupt areas of the Iberian North bear the signals of long‐term isolation in their maternal and paternal gene pools, the makeup of the Atlantic façade as a whole can be related to tribal population groups that predate the Roman conquest of the Peninsula. The maintenance through time of such a structure can be related to the numerous geographic barriers of the Iberian mainland, which have historically conditioned its settlement patterns and the occurrence of genetic drift processes. Am J Phys Anthropol 153:617–626, 2014. © 2013 Wiley Periodicals, Inc.
Phylogenetic comparative methods complement discriminant function analysis in ecomorphology
Authors: Barr W. Andrew , Scott Robert S.
Published: December 2013

In ecomorphology, Discriminant Function Analysis (DFA) has been used as evidence for the presence of functional links between morphometric variables and ecological categories. Here we conduct simulations of characters containing phylogenetic signal to explore the performance of DFA under a variety of conditions. Characters were simulated using a phylogeny of extant antelope species from known habitats. Characters were modeled with no biomechanical relationship to the habitat category; the only sources of variation were body mass, phylogenetic signal, or random “noise.” DFA on the discriminability of habitat categories was performed using subsets of the simulated characters, and Phylogenetic Generalized Least Squares (PGLS) was performed for each character. Analyses were repeated with randomized habitat assignments. When simulated characters lacked phylogenetic signal and/or habitat assignments were random, <5.6% of DFAs and <8.26% of PGLS analyses were significant. When characters contained phylogenetic signal and actual habitats were used, 33.27 to 45.07% of DFAs and <13.09% of PGLS analyses were significant. False Discovery Rate (FDR) corrections for multiple PGLS analyses reduced the rate of significance to <4.64%. In all cases using actual habitats and characters with phylogenetic signal, correct classification rates of DFAs exceeded random chance. In simulations involving phylogenetic signal in both predictor variables and predicted categories, PGLS with FDR was rarely significant, while DFA often was. In short, DFA offered no indication that differences between categories might be explained by phylogenetic signal, while PGLS did. As such, PGLS provides a valuable tool for testing the functional hypotheses at the heart of ecomorphology. Am J Phys Anthropol 153:663–674, 2014. © 2013 Wiley Periodicals, Inc.
Synthesis, Reactions, and Biological Activities of Some New Thieno[3,2‐c]quinoline and Pyrrolo[3,2‐c]quinoline Derivatives
Authors: Abdel‐Wadood Fatma K. , Abdel‐Monem Maisa I. , Fahmy Atiat M. , Geies Ahmed A.
Published: December 2013

2‐Bromo‐4‐fluoroaniline (1) was condensed with ethyl 2‐cyano‐3‐ethoxyacrylate (2) in ethanol to afford 3, which upon refluxing in paraffin oil at 250°C gave 8‐bromo‐3‐cyano‐6‐fluoroquinoline‐4(1H)‐one (4). Then, compound 4 was taken as a versatile building block that allows the synthesis of thieno[3,2‐c]quinoline, pyrrolo[3,2‐c]quinoline, and N‐methylpyrrolo[3,2‐c]quinoline systems. The newly synthesized compounds and their derivatives were characterized by elemental analysis and spectroscopy (IR, 1H NMR, 13C NMR, and mass). Furthermore, some of these synthesized compounds were screened for their biological activities against various pathogenic bacterial and fungal strains. Our results demonstrate that most of the synthesized compounds possess a significant broad antibacterial activity against all strains of both gram‐positive and gram‐negative bacteria. In addition, compound 5 showed remarkable antifungal activity.
The Plasma Cell Signature in Autoimmune Disease
Authors: Streicher Katie , Morehouse Christopher A. , Groves Christopher J. , Rajan Bhargavi , Pilataxi Fernanda , Lehmann Kim P. , Brohawn Philip Z. , Higgs Brandon W. , McKeever Kathleen , Greenberg Steven A. , Fiorentino David , Richman Laura K. , Jallal Bahija , Herbst Ronald , Yao Yihong , Ranade Koustubh
Published: December 2013

Objective

Production of pathogenic autoantibodies by self‐reactive plasma cells (PCs) is a hallmark of autoimmune diseases. We undertook this study to investigate the prevalence of PCs and their relationship to known pathogenic pathways to increase our understanding of the role of PCs in disease progression and treatment response.

Methods

We developed a sensitive gene expression–based method to overcome the challenges of measuring PCs using flow cytometry. Whole‐genome microarray analysis of sorted cellular fractions identified a panel of genes, IGHA1, IGJ, IGKC, IGKV4‐1, and TNFRSF17, expressed predominantly in PCs. The sensitivity of the PC signature score created from the combined expression levels of these genes was assessed through ex vivo experiments with sorted cells. This PC gene expression signature was used for monitoring changes in PC levels following anti‐CD19 therapy, for evaluating the relationship between PCs and other autoimmune disease–related genes, and for estimating PC levels in affected blood and tissue from patients with multiple autoimmune diseases.

Results

The PC signature was highly sensitive and capable of detecting a change in as few as 360 PCs. The PC signature was reduced more than 90% in scleroderma patients following anti‐CD19 treatment, and this reduction was highly correlated (r = 0.80) with inhibition of collagen gene expression. Evaluation of multiple autoimmune diseases revealed that 30–35% of lupus and rheumatoid arthritis patients had increased levels of PCs.

Conclusion

This newly developed PC signature provides a robust and accurate method of measuring PC levels in the clinic. Our results highlight subsets of patients across multiple autoimmune diseases who may benefit from PC‐depleting therapy.