bluuebunny/crossref_metadata_2025 huggingface dataset:
Accessibility as a Conditioning Factor in Treatment for Exudative Age-related Macular Degeneration
Authors: Real Juan P. , Luna José D. , Urrets-Zavalia Julio A. , De Santis Mariana O. , Palma Santiago D. , Granero Gladys E.
Published: May 2013

Purpose

Ranibizumab and bevacizumab coexist as the main therapeutic strategies for the treatment of neovascular age-related macular degeneration (NV-AMD). In Argentina, the access pathways to the drugs are different. Patients with different pathways and gatekeepers to access may experience different outcomes. The purpose of this work was to estimate the impact on therapeutic effects and visual outcome of the different accessibilities to NV-AMD treatment.

Methods

A retrospective analysis of the charts of 78 patients with previously untreated exudative AMD, who were treated with ranibizumab or bevacizumab between January 2009 and December 2011, was conducted. The main outcomes measured included time delay and change in mean best-corrected visual acuity (BCVA) between diagnosis and treatment and mean BCVA change at 1-year follow-ups.

Results

The delay between diagnosis and treatment and decrease in visual acuity over this time was significantly higher for patients treated with ranibizumab. At 1 year after the initiation of treatment, BCVA had a mean increase from baseline of 0.11 letters in the bevacizumab group with a mean of 4.71 injections, compared with a decrease of 8.87 letters with a mean of 2.98 injections in the ranibizumab group.

Conclusions

Access to treatment can be a key factor for success of therapy. Waiting times and availability of doses are crucial in the treatment of NV-AMD. Solving the problems related to delayed initiation of therapy and the difficulties in the maintenance phase are more important than define whether bevacizumab or ranibizumab is used.
Infectious Complications Associated with Percutaneous Nephrostomy Catheters: Do we know Enough?
Authors: Siddiq Danish M. , Darouiche Rabih O.
Published: May 2013

The percutaneous nephrostomy catheter (PCNC) has evolved since its inception. Over more than half a century, it has gone from a temporary maneuver to a permanent fixture in a large proportion of patients who have incurable illnesses with obstructed renal drainage systems. Unfortunately, the research looking specifically at infectious complications associated with PCNCs suffers from oversimplification as studies predominantly assess sepsis alone. There are no standardized definitions or criteria to define the various infectious complications described in this paper. Although the PCNC has a relative paucity of infectious complications, which represents an excellent marker for patient care, the low rate of infection dictates a large sample size for sufficiently-powered research studies to be able to find a significant impact of interventional measures. In this review article, we discuss various aspects of pathogenesis and treatment of the different subtypes of PCNC-associated infections.
Long-Term in vivo Impedance Changes of Subretinal Microelectrodes Implanted in Dystrophic P23H Rats
Authors: Linderholm Pontus , Guyomard Jean-Laurent , Djilas Milan , Salzmann Joël , Simonutti Manuel , Sahel José A. , Safran Avinoam B. , Renaud Philippe , Picaud Serge
Published: May 2013

Retinal prostheses are being developed to restore vision in blind patients with photoreceptor degeneration. Electrodes arrays were subretinally implanted in transgenic P23H rats with their photoreceptors degenerated. Electrical stability of the implants was evaluated by long-term monitoring of their impedance changes. Electrode impedances were found to increase by two log units over a three weeks period whereas no impedance increase was noted when the implants were located in the vitreous. In case of hemorrhage or major fibrous reactions, the impedance continued to increase steadily. After explantation, it recovered its initial value indicating no deterioration of the implant. Although the glial cell layer at the surface of the subretinal space was slightly larger, no major glial reaction was seen in direct contact to the implant. These results indicate that no functional testing should be considered before at least three weeks post implantation.
Detecting Psychological Phenomena: Taking Bottom-Up Research Seriously
Authors: Haig Brian D.
Published: May 2013

For more than 50 years, psychology has been dominated by a top-down research strategy in which a simplistic account of the hypothetico-deductive method is paired with null hypothesis testing in order to test hypotheses and theories. As a consequence of this focus on testing, psychologists have failed to pay sufficient attention to a complementary, bottom-up research strategy in which data-to-theory research is properly pursued. This bottom-up strategy has 2 primary aspects: the detection of phenomena, mostly in the form of empirical generalizations, and the subsequent understanding of those phenomena through the abductive generation of explanatory theories. This article provides a methodologically informative account of phenomena detection with reference to psychology. It begins by presenting the important distinctions between data, phenomena, and theory. It then identifies a number of different methodological strategies that are used to identify empirical phenomena. Thereafter, it discusses aspects of the nature of science that are prompted by a consideration of the distinction between data, phenomena, and explanatory theory. Taken together, these considerations press for significant changes in the way we think about and practice psychological research. The adoption of these changes would help psychology correct a number of its major current research deficiencies.
Affective Modulation of Attentional Switching
Authors: Heerebout Bram T. , Todorović Ana , Smedinga Hilde E. , Phaf R. Hans
Published: May 2013

Affective modulation of attentional switching may have developed early in evolution and may therefore have primacy over other affective influences. This behavioral study investigated the influence of affect on attentional switching between emotionally neutral stimuli, whether limited- capacity control processes are involved, and whether attentional flexibility should be distinguished from attentional broadening. Experiment 1 showed that suboptimally presented happy faces facilitated switching from an automatized response routine, whereas angry faces had the opposite effect. In Experiment 2, participants with a dominant global (i.e., broad) or local (i.e., narrow) spatial bias switched more easily to the opposite bias after suboptimal happy faces than after neutral primes but less easily after angry faces. Affective modulation of attentional switching was probably incorporated during evolution in many more complex forms of information processing.
Reducing False Memories via Context Reinstatement: The Roles of Encoding and Retrieval Contexts
Authors: Goodwin Kerri A.
Published: May 2013

Reinstatement of encoding strategies during recall was investigated in 3 experiments using the Deese-Roediger-McDermott paradigm (Deese, 1959; Roediger & McDermott, 1995). Participants studied lists using either elaborative or rote rehearsal encoding strategies. At test, participants either reinstated their original encoding strategies or used opposing strategies to recall. In Experiment 1, participants provided "think aloud" verbal reports during study and test, and elaborative encoding led to higher levels of correct recall, more instances of verbalizations of critical items, and lower false recall compared with rote encoding. Experiment 2 replicated the results of Experiment 1 without verbal reports. In Experiment 3, false recall was lower only after elaborative encoding and reinstatement of that encoding context. Results support the role of distinctiveness in false recall, which is sensitive to changes in list context and retrieval context after elaborative encoding.
COVID-19: Putting Stock Markets Back on Recovery among the Crude Oil Producing Economies
Authors: Olakojo Solomon A. , Onanuga Abayomi T. , Onanuga Olaronke T.
Published: May 2013

COVID-19 poses an unprecedented threat to components of global business cycles including stock markets, industrial production and employment. This study investigated its impact on stock markets of 24 oil producing COVID-19-hit economies in North America, South America, Europe, Asia, Oceania and Africa. It examined the nature of asymmetry in the business cycles of the sampled countries and the impact of COVID-19 on the asymmetry. Switching regression techniques were estimated with data covering the period from October 1, 2019 to April 14, 2020. The results confirmed the presence of negative asymmetry in stock market cycles in 54.2% of the sampled countries, out of which 38.5%, 46.2% and 15.4% are high, middle and low-middle income countries, respectively. This is significantly connected to the COVID-19 pandemic for 29.2% of the sample. The expected duration of being in the state of low stock market performance, due to COVID-19, reduces with levels of countries’ income, if regimes are dependent. Opposite was observed if regimes are independent. Hence, the negative impact of COVID-19 on stock markets in lower-income countries will linger compared to higher-income countries. Reducing COVID-19-associated risks will go a long way to revive investors’ confidence in the market and help to restart the engine of economic recovery in the sampled countries.
Improvement of Dissolution Rate of Chlorzoxazone by Solid Dispersion Technique and Development of Buccal Patch
Authors: Jagdale Swati , Hable Asawaree , Chabukswar Aniruddha , Kuchekar Bhanudas
Published: May 2013

Chlorzoxazone (CLZ) is insoluble in water. Its half life is 1.1 hr, dose is 250 mg and has first pass metabolism. Formation of solid dispersions of CLZ with pluronic F127 will enhance the bioavailability of the drug. Phase-solubility studies revealed AL type of curves, indicating the ability of pluronic F127 to disperse with CLZ and significantly increase in solubility. The solid dispersions of CLZ was carried out with pluronic F127 by different methods and characterized by in vitro drug release, drug content, FTIR, DSC, XRD. All the solid dispersions showed dissolution improvement compare to pure drug. These techniques revealed distinct loss of drug crystallinity in the formulation accounting for enhancement in dissolution rate. The stability study for solid dispersions indicated, all formulations were stable. Methods showing best in vitro drug release profile were selected in further development of mucoadhesive buccal patches. A buccal patch has been developed using mucoadhesive polymers HPMC K4M and carbapol 974. The developed patches were evaluated for the physicochemical, mechanical and drug release characteristics. The optimized patches showed good mechanical and physicochemical properties to withstand environment of oral cavity. The in-vitro permeation study showed that patches could deliver drug to the oral mucosa for a period of 8 hrs. The results indicate that suitable bioadhesive buccal patches with good permeability could be prepared. The batches FH4 and FC4 showed 79.65% and 79.93% permeated through goat mucosa membrane in 8 hrs. The stability study for buccal patch revealed that all batches were stable.
Fabrication and Characterization of Cu2ZnSnS4 Powders by a Hydrothermal Method
Authors: Hsu Kuo-Chin , Liao Jiunn-Der , Chao Li-Min , Fu Yaw-Shyan
Published: May 2013

In this study, Cu2ZnSnS4 (CZTS) powders are successfully synthesized by a simple hydrothermal method, and the concentration of thiourea, reaction time, reaction temperature, and precursor concentration ratio (Zn/Sn) are all examined in order to obtain the optimal conditions for this process. In addition, the characteristics of the resulting powder are examined using the X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), Raman, transmission electron microscope (TEM) and ultraviolet–visible (UV–vis) techniques. The results indicate that the concentration of sulfur ions is 6 times of that of the copper ions, and that the production process required a reaction time of 72 h and a reaction temperature of 180 °C, and the energy gap of the CZTS powder is approximately 1.45 eV.
Visualization of Oil Body Distribution in Jatropha curcas L. by Four-Wave Mixing Microscopy
Authors: Ishii Makiko , Uchiyama Susumu , Ozeki Yasuyuki , Kajiyama Sin'ichiro , Itoh Kazuyoshi , Fukui Kiichi
Published: May 2013

Jatropha curcasL. (jatropha) is a superior oil crop for biofuel production. To improve the oil yield of jatropha by breeding, the development of effective and reliable tools to evaluate the oil production efficiency is essential. The characteristics of the jatropha kernel, which contains a large amount of oil, are not fully understood yet. Here, we demonstrate the application of four-wave mixing (FWM) microscopy to visualize the distribution of oil bodies in a jatropha kernel without staining. FWM microscopy enables us to visualize the size and morphology of oil bodies and to determine the oil content in the kernel to be 33.2%. The signal obtained from FWM microscopy comprises both of stimulated parametric emission (SPE) and coherent anti-Stokes Raman scattering (CARS) signals. In the present situation, where a very short pump pulse is employed, the SPE signal is believed to dominate the FWM signal.
Current–Voltage Model of Bulk Fin Field-Effect Transistors with a Half-Circle Corner
Authors: Choi Byung-Kil , Jeong Min-Kyu , Kwon Hyuck-In , Park Byung-Gook , Lee Jong-Ho
Published: May 2013

The drain current of fully depleted (FD) nanoscale bulk FinFETs with the top-channel of a half-circle shape was modeled, for the first time, systematically in all operational regions and compared with the data obtained from three-dimensional (3D) device simulation. In the current model of these devices, it is very important to have accurate threshold voltages for side-channels and top-channel, and take the field penetration effect induced by the top-gate near the top of a fin body into account the threshold voltage (V
th) models for top-channels and side-channels, respectively. So, we obtained successfully the V
th models [V
th0t (V
th model of top-channel at a low drain bias) and V
th0s (V
th model of side-channels at a low drain bias)] considering the field penetration effect for both channels (top- and side-channels) to model the current behaviors in the doped bulk FinFETs with the top-channel of a half-circle shape. Our compact current model with V
th0t and V
th0s predicted accurately the current behaviors of the devices and shown a good agreement with 3D simulation.
The Influence of Dissolved Carbon Dioxide on Cavitation Intensity in Ultrasound Cleaning Systems
Authors: Brems Steven , Hauptmann Marc , Camerotto Elisabeth , Pacco Antoine , Struyf Herbert , Mertens Paul , Gottschalk Christiane , Gendt Stefan De
Published: May 2013

A study is made of the effect of dissolved CO2 on cavitation inception and activity in an ultrasound system with a sound frequency of 928 kHz. It is shown that measurable cavitation activity is completely absent at moderate acoustic power densities (≤1.7 W cm-2) when only CO2 is dissolved in ultra pure water. It is suggested that the enhanced stability of CO2 bubbles against coalescence might be the origin of the delayed cavitation inception when compared to other dissolved gases. A combination of dissolved O2 and CO2 can lead to a measurable cavitation activity at an acoustic power of 420 mW cm-2, but an increase of the dissolved CO2 level reduces, in general, the observed cavitation activity. In order to compare results with different dissolved gas concentrations, measurements are performed with acoustic pulses and the pulse off time is varied. An optimal pulse-off time exists, where a maximum of cavitation activity is observed. However, the pulse-off time interval with enhanced cavitation activity is narrowed with increasing dissolved CO2 concentrations. Again, a decrease in bubble coalescence might explain the narrowing of the “enhancement peak”.
Preparation of Bulk AlN Seeds by Spontaneous Nucleation of Freestanding Crystals
Authors: Hartmann Carsten , Wollweber Juergen , Dittmar Andrea , Irmscher Klaus , Kwasniewski Albert , Langhans Frank , Neugut Tom , Bickermann Matthias
Published: May 2013

Freestanding AlN single crystals are grown in a RF-heated furnace by physical vapor transport (PVT). Three different growth regimes with growth temperatures between 2080–2200°C result in different crystal habits and very high structural quality. The Rocking curves show FWHM < 21 arcsec in the 0002 and 101̄0 Reflection on the as-grown facets. Isometric AlN crystals with sizes up to 10 × 10 × 12mm3show a zonar structure consisting of a yellowish core area which is grown on the N-polar (0001̄) facet and a nearly colorless edge region grown on prismatic {101̄0} facets. In the two growth zones nearly the same C concentrations but different amounts of O and Si are measured by secondary ion mass spectrometry (SIMS). The yellowish core area show a very low defect density (EPD ⩽ 100 cm−2) and a higher deep UV transparency compared to the edge region.
Investigation of Growth Mechanism for InGaN by Metal–Organic Vapor Phase Epitaxy Using Computational Fluid Simulation
Authors: Deura Momoko , Ichinohe Fumitaka , Arai Yu , Shiohama Kenichi , Hirako Akira , Ohkawa Kazuhiro
Published: May 2013

We investigated the mechanism of metal–organic vapor phase epitaxy (MOVPE) growth for InGaN by comparing experimental and simulation results. The simulation results showed a similar trend to the experimental results. Therefore, the simulation system can be used to speculate on physical and chemical phenomena through the behavior of precursors. InGaN growth is largely affected by the amounts of both trimethylindium (TMIn) and NH3 supplied. This is because InN growth is dependent on the amount of NH2 physisorbed on a surface, which is generated by NH3. Moreover, the decomposition of crystallized InN and the desorption of these decomposed precursors of InN during growth cannot be ignored.
Strain-Compensated Effect on the Growth of InGaN/AlGaN Multi-Quantum Well by Metalorganic Vapor Phase Epitaxy
Authors: Doi Tomohiro , Honda Yoshio , Yamaguchi Masahito , Amano Hiroshi
Published: May 2013

InGaN/AlGaN multi-quantum wells (MQWs) were grown by metalorganic vapor phase epitaxy. The In composition of the InGaN well layer was found to increase with the tensile strain of the AlGaN barrier layer. The InGaN/AlGaN strain-compensated structure can be grown at a higher growth temperature than that of the InGaN/GaN MQW, which shows that the same emission wavelength and thus the density of the V-defects can be effectively suppressed.
Crack-Free Thick AlN Films Obtained by NH3 Nitridation of Sapphire Substrates
Authors: Banal Ryan G. , Akashi Yosuke , Matsuda Kazuhisa , Hayashi Yuki , Funato Mitsuru , Kawakami Yoichi
Published: May 2013

We demonstrate that NH3 nitridation of sapphire substrates effectively suppresses cracks in AlN epilayers. The sapphire nitridation promoted three-dimensional (3D) growth at the initial stage, in contrast to the 2D growth mode on non-nitrided sapphire. The coalescence of 3D columnar grains in the process created voids, which act as strain absorber and thus crack-free thick epilayers were obtained. The control of nitridation period is also found important. The optimum nitridation period realized an atomically-smooth epilayer with superior structural quality. On the other hand, the least nitrided sapphire exhibited high twist mosaic of the grains which complicate the epilayer smoothing process, and the longer nitridation promoted slow recovery of a smooth epilayer.
Selective Area Growth of Semipolar (202̄1) and (202̄1̄) GaN Substrates by Metalorganic Vapor Phase Epitaxy
Authors: Jinno Daiki , Ma Bei , Miyake Hideto , Hiramatsu Kazumasa , Enatsu Yuuki , Nagao Satoru
Published: May 2013

We carried out the selective area growths of GaN on semipolar (202̄1), (202̄1̄), and related non- and semi-polar GaN substrates by metalorganic vapor phase epitaxy. By changing the growth parameters and directions of the SiO2 stripe mask, the differences in GaN structures between the growths on the different substrates were investigated. In the case of the stripes ∥ a-axis, anisotropic GaN structures with (0001̄) and (101̄1) facets were obtained for all the non- and semi-polar GaN substrates. On the other hand, in the case of the stripes ⊥ a-axis, isotropic GaN structures were obtained for the (202̄1) and (202̄1̄) GaN substrates. However, the GaN structures between them were quite different. After 120 min of growth, {112̄0} and (202̄1̄) facets markedly expanded for the (202̄) and (202̄1̄) GaN substrates, respectively. Moreover, by exploiting the effect of growth temperature, the growth of a continuous (202̄1̄) GaN layer with voids was realized.
Evaluation of {112̄2} Semipolar Multiple Quantum Wells Using Relaxed Thick InGaN Layers with Various In Compositions
Authors: Uchida Katsumi , Miyoshi Seita , Yamane Keisuke , Okada Narihito , Tadatomo Kazuyuki , Kuwano Noriyuki
Published: May 2013

We have succeeded in the growth of a high-quality semipolar {112̄2} GaN layer on anr-plane patterned sapphire substrate (r-PSS). In this study, we fabricated light-emitting diodes (LEDs) using relaxed thick InGaN layers with various In compositions. There were significant changes in polarization properties, indicating lattice mismatch reduction due to the use of a relaxed thick InGaN layer. Electroluminescence (EL) intensity was improved by using a relaxed thick InGaN layer with low In composition. In particular, the EL intensity improved approximately twofold compared with that in the case of LEDs without relaxed thick InGaN layers at an injection current of 200 mA.
Effect of High NH3Input Partial Pressure on Hydride Vapor Phase Epitaxy of InN Using Nitrided (0001) Sapphire Substrates
Authors: Togashi Rie , Yamamoto Sho , Karlsson K. Fredrik , Murakami Hisashi , Kumagai Yoshinao , Holtz Per-Olof , Koukitu Akinori
Published: May 2013

The influence of the source gas supply sequence prior to growth and the NH3input partial pressure (PoNH3) on the nucleation of InN islands during the initial stages of hydride vapor phase epitaxy on a nitrided (0001) sapphire substrate was investigated. The crystalline quality of the InN layer after subsequent lateral growth was also examined. When NH3was flowed prior to growth, single-crystal hexagonal InN islands formed. When InN was grown with a higherPoNH3, the number of InN islands decreased remarkably while their diameter increased. The crystalline quality of InN grown on the hexagonal islands with a highPoNH3significantly improved with increasing growth time. A strong PL spectrum was observed only from InN layers grown with a highPoNH3. It was thus revealed that an NH3preflow and a highPoNH3are effective for producing InN with high crystalline quality and good optical and electrical properties.
Characterization of GaN Nanowall Network and Optical Property of InGaN/GaN Quantum Wells by Molecular Beam Epitaxy
Authors: Zhong Aihua , Hane Kazuhiro
Published: May 2013

A GaN nanowall network and InGaN/GaN quantum wells were grown on AlN/Si(111) substrates by molecular beam epitaxy (MBE). The morphology, polarity, structural, and optical properties of the GaN nanowall network were investigated. The lattice constants a
0= 3.193 Å and c
0 = 5.182 Å of the GaN nanowall network were obtained by X-ray diffraction (XRD), indicating that the GaN nanowall network is under low stress. Chemical etching test shows that the GaN nanowall network grown on an Al-polar buffer layer is Ga-polar. Photoluminescence (PL) spectra of InGaN/GaN quantum wells both on a GaN nanowall network and a GaN film were also measured. Different from the InGaN/GaN quantum wells on GaN film, the Fabry–Perot effect is not observed in the PL spectrum of the InGaN/GaN quantum wells on the GaN nanowall network owing to its antireflective porous structure. The emission wavelength gradually blue shifts from 408 to 391 nm with the decrease of temperature from 293 to 10 K. The GaN nanowall network grown on a Si substrate is not only compatible with mature Si micromachining technology but also may provide a novel nano-optical device.
Analysis of Broken Symmetry in Convergent-Beam Electron Diffraction along <112̄0 > and <11̄00 > Zone-Axes of AlN for Polarity Determination
Authors: Imura Masataka , Gautam Ujjal , Nakajima Kiyomi , Koide Yasuo , Amano Hiroshi , Tsuda Kenji
Published: May 2013

To accurately and easily determine the polarity of AlN using transmission electron microscopy, we compare the convergent-beam electron diffraction (CBED) patterns along the widely used <112̄0 > and <11̄00 > zone-axes. For the <112̄0 > zone-axis, the diffraction disk of g= 0002 differs from that of g= 0002̄, while for <11̄00 >, the diffraction disks of g= 0002 and 0002̄ are similar. The preferential clarity of these two disks is explained using Bloch-wave dynamical theory. To further support the explanation, we compare the results of GaN case. On the basis of our analysis, we conclude that the CBED patterns of the <112̄0 > zone-axis are more useful for accurately determining AlN polarity compared to the CBED patterns along the <11̄00 > zone-axis.
633 nm Red Emissions from InGaN Nanocolumn Light-Emitting Diode by Radio Frequency Plasma Assisted Molecular Beam Epitaxy
Authors: Vadivelu Ramesh , Igawa Yusuke , Kishino Katsumi
Published: May 2013

GaN nanocolumns exhibiting high light-extraction property provide a platform for high-performance nano-devices. To improve the performance of nanocolumn LEDs, uniform arrays of InGaN-based multi quantum well (MQW) nanocolumns were fabricated. We report on red emitting nanocolumn LEDs with InGaN MQW grown on GaN templates by radio frequency plasma assisted molecular beam epitaxy (RF-MBE), for the first time. The electroluminescence peak wavelength and the full-width at half maximum at a drive current of 5 mA were 633 nm and 185 meV, respectively for the LEDs. It demonstrated a blue-shift of 5 nm for the 20 mA, indicating negligible polarization and band filling effects.
Combination of Indium–Tin Oxide and SiO2/AlN Dielectric Multilayer Reflective Electrodes for Ultraviolet-Light-Emitting Diodes
Authors: Nakashima Tsubasa , Takeda Kenichiro , Shinzato Hiroshi , Iwaya Motoaki , Kamiyama Satoshi , Takeuchi Tetsuya , Akasaki Isamu , Amano Hiroshi
Published: May 2013

We have investigated novel reflective electrodes by combining an indium–tin oxide (ITO) layer and a SiO2/AlN dielectric multilayer (DM) for UV-light-emitting diodes (LEDs). The reflectance of 10 pairs of SiO2/AlN DM reached 98.5% at 350 nm. As a result, the ITO/DM electrodes simultaneously satisfied the requirements of high reflectivity in the UV region, good contact characteristics, and current spreading. The light output power of the UV LED with an ITO/DM electrode is 1.2 and 1.6 times higher than those of LEDs with ITO/Al and Ni/Au electrodes, respectively.
In-Well Pumped Blue GaN-Based Vertical-External-Cavity Surface-Emitting Lasers
Authors: Wunderer Thomas , Northrup John E. , Yang Zhihong , Teepe Mark , Johnson Noble M. , Rotella Paul , Wraback Michael
Published: May 2013

We describe the properties of in-well pumped blue InGaN/GaN vertical-external-cavity surface-emitting lasers. The laser hetero-structures were deposited on bulk GaN substrates by using metal–organic vapor phase epitaxy near atmospheric pressure. The active zones are comprised of up to 20 InGaN quantum wells distributed in a resonant periodic gain configuration. High-reflectivity dielectric distributed Bragg-reflectors were used as mirrors. Lasing was achieved at a wavelength of about 440–445 nm by exclusively exciting the quantum wells with the 384 nm emission line of a dye/N2 laser. The laser threshold was about 240 kW/cm2. The small pump spot diameter of about 20 µm and the usage of dielectric mirrors result in a rather high thermal resistance, which was experimentally determined by using an all optical measurement technique based on the temperature-dependent change of the refractive index of the device.
Blue Superluminescent Light-Emitting Diodes with Output Power above 100 mW for Picoprojection
Authors: Kopp Fabian , Eichler Christoph , Lell Alfred , Tautz Sönke , Ristić Jelena , Stojetz Bernhard , Höß Christine , Weig Thomas , Schwarz Ulrich T. , Strauss Uwe
Published: May 2013

We present a blue InGaN research and development superluminescent light-emitting diode (SLED) that is suitable for picoprojection. The SLED reaches an output power of >100 mW with a peak wavelength of 443 nm and a spectral bandwidth of >2.6 nm as well as a single-mode far-field driven in cw mode at 25 °C. In order to figure out an optimized waveguide design, which enables such a high output power at lowest operation current, we compare the performance of diodes with curved and tilted shaped ridges in detail, using the lasing threshold current as a criterion for lasing or superluminescence, respectively.
Wavelength Dependence of Internal Electric Field on Local Structure of Green-Yellow InGaN/GaN Quantum Wells
Authors: Hwang Jong-Il , Hashimoto Rei , Saito Shinji , Nunoue Shinya
Published: May 2013

We have performed photoluminescence (PL) measurements for green–yellow InGaN/GaN multiple quantum wells (MQWs) in which InGaN layer was embedded in the barrier layer to verify the effect on the crystal quality and the internal electric field (F0). From the analysis of both the time-resolved PL and the excitation-power dependence of PL, it has been revealed that the PL intensities and the decay time were enhanced for the MQWs with the InGaN interlayer although the wavelength dependence of theF0scarcely changes. This indicates that the InGaN interlayer suppresses the degradation of InGaN quantum well rather than the quantum-confinement Stark effect, suggesting that optical properties can be improved by improving the crystal quality through optimizing the local structure as well as the growth conditions. From the light-emitting diodes using the interlayer, we obtained an output power of 10.1 mW at 20 mA at 552 nm.
Suppression of Nonradiation Recombination by Selected Si Doping in AlGaN Barriers for Ultraviolet Light-Emitting Diodes
Authors: Lu Yu-Hsuan , Fu Yi-Keng , Huang Shyh-Jer , Su Yan-Kuin , Chen Ying-Chih , Xuan Rong , Pilkuhn Manfred H.
Published: May 2013

The effect of selective Si doping on the emission efficiency in ultraviolet (UV) light-emitting diodes (LEDs) is investigated both experimentally and theoretically. The results show that the light output power increases with the number of Si-doped barriers (QBs). Experimental results indicate that compared with an all-undoped-QB LED, a factor of 3.17 can be achieved for the output power of an all-doped-QB LED at 350 mA. Detailed analysis on this phenomenon shows that the Si-doped QB is beneficial to suppress the nonradiative recombination rate by excess electrons in doped barriers.
Integrated Over-Temperature Protection Circuit for GaN Smart Power ICs
Authors: Kwan Alex Man Ho , Guan Yue , Liu Xiaosen , Chen Kevin J.
Published: May 2013

As a thermal sensing and protection module on a GaN smart power IC platform, the first GaN over-temperature protection (OTP) circuit is demonstrated to deliver a desirable triggering signal at the critical temperature. The integrated OTP circuit is realized based on monolithic integration of enhancement-/depletion-mode high electron mobility transistors (HEMT) and HEMT-compatible lateral field effect rectifiers on a baseline AlGaN/GaN-on-Si wafer. The circuit effectively indicates the over-temperature up to 250 °C, and has a power supply rejection radio well above 35 dB. This sensing/protection circuit is expected to provide enhanced reliability to the high-voltage GaN power devices.
Comparison of Semiconductor–Electrolyte and Semiconductor–Metal Schottky Junctions Using AlGaN/GaN Photoelectrochemical Electrode
Authors: Nakamura Akihiro , Sugiyama Masakazu , Fujii Katsushi , Nakano Yoshiaki
Published: May 2013

A semiconductor photoelectrochemical electrode that contains a heterostructure at the surface vicinity is attractive as a corrosion-tolerant electrode. In order to clarify its basic characteristics, the differences in Schottky junctions were evaluated using the semiconductor capacitance dependence on voltage. The Mott–Schottky relationship of a thin AlGaN layer on GaN was different from that of GaN bulk. The Schottky junctions were formed not only by using an electrolyte contact, but also by using a metal electrode to evaluate the effects of the semiconductor–electrolyte interface. Although diffusions of ions and solvents occur in the electrolyte, the Mott–Schottky plot measured for the electrolyte system showed a similar voltage dependence slope to that measured with a metal contact. This indicates that an electrolyte has a limited effect on the depletion behavior of the semiconductor heterojunction electrode.
Association Between Fatigue and Pain in Rheumatoid Arthritis: Does Pain Precede Fatigue or Does Fatigue Precede Pain?
Authors: van Dartel S. A. A. , Repping‐Wuts J. W. J. , van Hoogmoed D. , Bleijenberg G. , van Riel P. L. C. M. , Fransen J.
Published: May 2013

Objective

Fatigue and pain are important symptoms for patients with rheumatoid arthritis (RA), but their temporal association is unknown. Therefore, the objective of this study was to investigate the longitudinal relationship between fatigue and pain in patients with RA using time‐lag models.

Methods

Consecutive RA outpatients (n = 228) were enrolled for this 1‐year study. Fatigue was assessed monthly with the Checklist Individual Strength (CIS; range 8–56) and pain was assessed monthly with the bodily pain subscale (inverted, range 0–100) of the Short Form 36. The association between monthly changes in fatigue and pain was analyzed using longitudinal regression (mixed models), using the same months and with a 1‐month time lag.

Results

A total of 198 patients were included in the analyses. At baseline, the mean ± SD pain score was 35.23 ± 19.82 and the mean ± SD CIS fatigue score was 31.0 ± 12.4. Severe fatigue at baseline (CIS score ≥35) was present in 42% of the patients. The mean ± SD patient‐averaged CIS fatigue score over 1 year was 30.9 ± 6.0 and the mean ± SD patient‐averaged pain score over 1 year was 36.4 ± 18.3. The longitudinal regression analysis showed a significant positive relationship between fatigue and pain during the same month (β = 2.04; 95% confidence interval 1.82, 2.27). The models using a time lag showed no significant association between changes in pain and changes in fatigue.

Conclusion

In established RA, pain and fatigue show monthly fluctuations that are synchronous rather than showing a temporal relationship with a time lag; within this timeframe, the results do not indicate that one precedes the other.
Biological and Bioinspired Composites with Spatially Tunable Heterogeneous Architectures
Authors: Studart André R.
Published: May 2013

The design and fabrication of synthetic structural components often result in homogeneous materials with uniform microstructures and properties. In contrast, nature has evolved structural composites exhibiting rich heterogeneous architectures and tunable site‐specific properties. Creating synthetic systems with the heterogeneous nature of biological materials should enable the fabrication of composites with extended durability under severe mechanical demands or with adequate properties using, for example, a more restricted selection of bioresorbable or environmental‐friendly basic building blocks. Here, the heterogeneous structures of the tooth and of the tendon‐bone interface are revisited to identify design strategies that have been naturally selected to best respond to the non‐uniform stresses distributions typically found in such load‐bearing structures. Recent attempts to replicate some of these strategies in man‐made materials are also shown to illustrate the variety of unusual properties that can be achieved through the proposed bioinspired approach. Finally, the creation of heterogeneous architectures with local microstructure and properties deliberately tuned to match non‐uniform loading conditions is suggested as a new pathway towards the development of “material systems” with unprecedented functionalities and durability in mechanically challenging applications.
Pressure Sensing and Electronic Amplification with Functionalized Graphite–Silicone Composite
Authors: Littlejohn Samuel , Nogaret Alain , Prentice Giles M. , Pantos G. Dan
Published: May 2013

A flexible yet electronically active composite that mimics mechanoreceptor neurons in the human skin is synthesized, generating voltage oscillations whose frequency increases with pressure. By encoding pressure into frequency, the sensor achieves a high pressure sensitivity (<10 Pa). The ability to sense pressure and to amplify signals arises from the robust negative differential resistance of functionalized graphitic flakes in silicone.
Hierarchically Structured, Double‐Periodic Inverse Composite Opals
Authors: Retsch Markus , Jonas Ulrich
Published: May 2013

A versatile colloidal templating strategy to fabricate hierarchically structured inverse opals is investigated. A sequence of infiltration and pyrolysis steps provides access to a range of material combinations such as SiO2, Al2O3, or TiO2. The experimental results also document the feasibility of this method to fabricate porous polymer films with a double periodic pore lattice.
Strongly Coupled Nanorod Vertical Arrays for Plasmonic Sensing
Authors: Wei Wenbo , Chen Kuan , Ge Guanglu
Published: May 2013

Due to their unique optical properties and facile processability, nanorods of noble metals are promising for highly effective nanoscale optical devices. Specifically, the local electric field enhancement brought about by plasmon coupling between nanorods in an array configuration shows great potential for optical sensing. Recent results demonstrate that vertical arrays of noble metal nanorods, used as substrates for surface enhanced Raman scattering, can achieve the sensitivity levels required for presymptomatic detection. Meanwhile, advancements in controlled fabrication methods can provide nanorod arrays with well‐defined structures and properties, which lays the foundation for highly sensitive and reliable sensing. This research news focuses on this rapidly developing field by introducing the mechanisms, characteristics, and preparation methods of nanorod arrays used in plasmonic sensing, along with a perspective for future development and technical requirements.
Carbonaceous Electrode Materials for Supercapacitors
Authors: Hao Long , Li Xianglong , Zhi Linjie
Published: May 2013

Supercapacitors have been widely studied around the world in recent years, due to their excellent power density and long cycle life. As the most frequently used electrode materials for supercapacitors, carbonaceous materials attract more and more attention. However, their relatively low energy density still holds back the widespread application. Up to now, various strategies have been developed to figure out this problem. This research news summarizes the recent advances in improving the supercapacitor performance of carbonaceous materials, including the incorporation of heteroatoms and the pore size effect (subnanopores' contribution). In addition, a new class of carbonaceous materials, porous organic networks (PONs) has been managed into the supercapacitor field, which promises great potential in not only improving the supercapacitor performances, but also unraveling the related mechanisms.
Nanomaterials for Reducing Amyloid Cytotoxicity
Authors: Zhang Min , Mao Xiaobo , Yu Yue , Wang Chen‐Xuan , Yang Yan‐Lian , Wang Chen
Published: May 2013

This review is intended to reflect the recent progress on therapeutic applications of nanomaterials in amyloid diseases. The progress on anti‐amyloid functions of various nanomaterials including inorganic nanoparticles, polymeric nanoparticles, carbon nanomaterials and biomolecular aggregates, is reviewed and discussed. The main functionalization strategies for general nanoparticle modifications are reviewed for potential applications of targeted therapeutics. The interaction mechanisms between amyloid peptides and nanomaterials are discussed from the perspectives of dominant interactions and kinetics. The encapsulation of anti‐amyloid drugs, targeted drug delivery, controlled drug release and drug delivery crossing blood brain barrier by application of nanomaterials would also improve the therapeutics of amyloid diseases.
Comparative analysis of subgrid drag modifications for dense gas‐particle flows in bubbling fluidized beds
Authors: Schneiderbauer Simon , Puttinger Stefan , Pirker Stefan
Published: May 2013

Many subgrid drag modifications have been put forth to account for the effect of small unresolved scales on the resolved mesoscales in dense gas‐particle flows. These subgrid drag modifications significantly differ in terms of their dependencies on the void fraction and the particle slip velocity. We, therefore, compare the hydrodynamics of a three‐dimensional bubbling fluidized bed computed on a coarse grid using the drag correlations of the groups of (i) EMMS, (ii) Kuipers, (iii) Sundaresan, (iv) Simonin, and the homogenous drag law of (v) Wen and Yu with fine grid simulations for two different superficial gas velocities. Furthermore, we present an (vi) alternative approach, which distinguishes between resolved and unresolved particle clusters revealing a grid and slip velocity dependent heterogeneity index. Numerical results are analyzed with respect to the time‐averaged solids volume fraction and its standard deviation, gas and solid flow patterns, bubble size, number density, and rise velocities. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4077–4099, 2013
Process synthesis and optimization of a sustainable integrated biorefinery via fuzzy optimization
Authors: Ng Rex T. L. , Hassim Mimi H. , Ng Denny K. S.
Published: May 2013

Over the last decade, utilization of biomasses is highly encouraged to conserve scarce resources, reduce dependency on energy imports as well as protect the environment. Integrated biorefinery emerged as noteworthy concept to integrate several conversion technologies to have more flexibility in product generation with energy self‐sustained and reduce the overall cost of the process. Integrated biorefinery is a processing facility that converts biomass feedstocks into a wide range of value added products via multiple technologies. In this work, a systematic approach for the synthesis and optimization of a sustainable integrated biorefinery which considers economic, environmental, inherent safety, and inherent occupational health performances is presented. Fuzzy optimization approach is adapted to solve four parameters simultaneously as they are often conflicting in process synthesis and optimization of an integrated biorefinery. An integrated palm oil‐based biorefinery case study is solved to demonstrate the proposed approach. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4212–4227, 2013
Thermodynamics of shear‐induced phase transitions for multicomponent fluid mixtures
Authors: Cañas‐Marín Wilson A.
Published: May 2013

A thermodynamic approach for modeling the phase equilibrium of multicomponent fluid mixtures under the influence of an applied shear rate (shear stress) is presented. This approach is based on assuming that, for the modeled mixtures, the viscosity variation with shear rate can be well‐described by using a power law. This framework is then used for predicting the influence of shear rate on the critical temperature, critical pressure, and spinodal curve of several Newtonian multicomponent hydrocarbon mixtures; giving as a result that for these kind of mixtures and depending on the composition, the critical temperature exhibits both an upward and downward shift with shear rate, whereas the critical pressure always exhibits a downward trend. Both a suppression of the liquid–liquid transition and shrinkage of the spinodal curves (mixing effect) are also predicted. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4383–4389, 2013
A genome‐wide association study of sleep habits and insomnia
Authors: Byrne Enda M. , Gehrman Philip R. , Medland Sarah E. , Nyholt Dale R. , Heath Andrew C. , Madden Pamela A. F. , Hickie Ian B. , Van Duijn Cornelia M. , Henders Anjali K. , Montgomery Grant W. , Martin Nicholas G. , Wray Naomi R. ,   The Chronogen Consortium
Published: May 2013

Several aspects of sleep behavior such as timing, duration and quality have been demonstrated to be heritable. To identify common variants that influence sleep traits in the population, we conducted a genome‐wide association study of six sleep phenotypes assessed by questionnaire in a sample of 2,323 individuals from the Australian Twin Registry. Genotyping was performed on the Illumina 317, 370, and 610K arrays and the SNPs in common between platforms were used to impute non‐genotyped SNPs. We tested for association with more than 2,000,000 common polymorphisms across the genome. While no SNPs reached the genome‐wide significance threshold, we identified a number of associations in plausible candidate genes. Most notably, a group of SNPs in the third intron of the CACNA1C gene ranked as most significant in the analysis of sleep latency (P = 1.3 × 10−6). We attempted to replicate this association in an independent sample from the Chronogen Consortium (n = 2,034), but found no evidence of association (P = 0.73). We have identified several other suggestive associations that await replication in an independent sample. We did not replicate the results from previous genome‐wide analyses of self‐reported sleep phenotypes after correction for multiple testing. © 2013 Wiley Periodicals, Inc.
Ionic‐liquid‐promoted Four‐component One‐pot Synthesis of Highly Functionalized Benzimidazo[2,1‐b][1,3]thiazines: Facile Construction of N‐fused Heterocycles
Authors: Siddiqui I. R. , Srivastava Anjali , Shamim Shayna , Srivastava Arjita , Shireen  , Waseem Malik A. , Abumhdi Afaf A. H. , Rahila  , Srivastava Anushree , Rai Pragati , Singh R. K. P.
Published: May 2013

A one‐pot, four‐component, efficient, and facile synthesis of highly functionalized benzimidazo[2,1‐b][1,3]thiazines promoted by ionic liquid ([bmim]Br)/Et3N has been developed. The protocol involves nucleophilic addition of o‐phenylenediamine to carbon disulfide to give 2‐mercaptobenzimidazole. After nucleophilic addition to the activated olefinic bond of a zwitterionic intermediate, which is generated by reaction of isocyanide with an electrophilic alkyne, subsequent cyclization gives benzimidazo[2,1‐b][1,3]thiazines with high atom economy. The ionic liquid was recovered and reused without any appreciable decrease in activity and product yield.