bluuebunny/crossref_metadata_2025 huggingface dataset:
Combined blazed grating and microlens array for color image sensing
Authors: Hirano Tadayuki , Shimatani Naoko , Kintaka Kenji , Nishio Kenzo , Awatsuji Yasuhiro , Ura Shogo
Published: February 2014

A combination of a blazed grating and a microlens array is discussed for high-efficiency color image sensing. Each image segment includes a microlens with blazed grating and three photodiodes assigned to red, green, and blue colors. Color-splitting performances of design examples were simulated by the two-dimensional finite-difference time-domain method. It was found that the spectral characteristics were similar to the ideal NTSC specifications for a segment size of 10 µm with a polymer microlens and a TiO2 blazed grating. A prototype consisting of a honeycomb array of microlenses of 15 µm cell diameter and a TiO2 blaze grating of 1.22 µm period and 0.35 µm height was fabricated and characterized. Power utilization efficiency of about 60% was predicted theoretically and estimated experimentally, which is much higher in comparison to a conventional image sensor utilizing color filters.
Estimation of the pressure–distance product for thermalization in sputtering for some selected metal atoms by Monte Carlo simulation
Authors: Nakano Takeo , Baba Shigeru
Published: February 2014

We propose a method to obtain the pressure–distance product (pd) for thermalization in the sputtering process using a Monte Carlo (MC) simulation. Sputter-ejected atoms proceed forward with high energy, and fall into random motion finally. That is, after many MC trials the “average position” of atoms reaches saturation. The thermalization distance d can be estimated from this saturation position. We could obtain the pd product for Al, Cu, and Mo in argon atmosphere. The pd values agreed well with the pressure dependence of the deposition profile observed experimentally.
Temperature dependent characteristics of the random telegraph noise on contact resistive random access memory
Authors: Chang Liang-Shun , Lin Chrong Jung , King Ya-Chin
Published: February 2014

The temperature dependent characteristics of the random telegraphic noise (RTN) on contact resistive random access memory (CRRAM) are studied in this work. In addition to the bi-level switching, the occurrences of the middle states in the RTN signal are investigated. Based on the unique its temperature dependent characteristics, a new temperature sensing scheme is proposed for applications in ultra-low power sensor modules.
Hydrochloric acid modification process for fabricating Bi2Sr2CaCu2O8+
x THz oscillator stack on-chip coupled to THz detector
Authors: Nishikata Tsubasa , Kato Takahiro , Kotaki Yukio , Suematsu Hisayuki , Kawakami Akira , Yasui Kanji
Published: February 2014

We fabricated Bi2Sr2CaCu2O8+δ (Bi-2212) intrinsic Josephson junctions (IJJ) integrating of an oscillator and a detector by double side photolithography and material modification with a dilutehydrochloric acid solution (pH = 1.65) within a monolithic Bi-2212 crystal. The dilute hydrochloric solution modifies Bi-2212 to insulating BiOCl. Various lateral dimensions of the oscillator IJJ from 45 × 8 to 95 × 30 µm2 were formed; all of the detectors were about 15 × 10 to 15 × 30 µm2 in lateral dimensions. These stacks have 180–416 junctions. Zero voltage current for the detector stack was measured at 77 K while sweeping a bias voltage in the oscillator stack. The zero voltage current of the detector stack was strongly suppressed when a kink structure in the current–voltage curve of the oscillator stacks appeared. This indicates that the oscillator stack emits radiation at this voltage. From the Josephson voltage-frequency relation, it is found that the voltage corresponds to about 0.5–1 THz.
High-efficiency thin and compact concentrator photovoltaics using micro-solar cells with via-holes sandwiched between thin lens-array and circuit board
Authors: Itou Akihiro , Asano Tetsuya , Inoue Daijiro , Arase Hidekazu , Matsushita Akio , Hayashi Nobuhiko , Futakuchi Ryutaro , Inoue Kazuo , Yamamoto Masaki , Fujii Eiji , Nakagawa Tohru , Anda Yoshiharu , Ishida Hidetoshi , Ueda Tetsuzo , Fidaner Onur , Wiemer Michael , Ueda Daisuke
Published: February 2014

We have developed a compact concentrator photovoltaic (CPV) module that comprises micro-solar cells with an area of ≈0.6 × 0.6 mm2 sandwiched between a 20-mm-thick lens array and a 1-mm-thick circuit board with no air gap. To establish electrical connections between the circuit board and the micro-solar cells, we developed a micro-solar cell with positive and negative electrodes on the lower face of the cell. In this study, we demonstrated the photovoltaic performance of the micro-solar cell closely approaches that of the standard solar cell measuring ≈5 × 5 mm2 commonly used in conventional CPVs under concentrated illumination. Our study showed that the negative effect on PV performance of perimeter carrier recombination in the micro-solar cell was insignificant under concentrated illumination. Finally, we assembled our micro-solar cells into a CPV module and achieved the module energy conversion efficiency of 34.7% under outdoor solar illumination.
Diffusion coefficients of impurity atoms in BaSi2 epitaxial films grown by molecular beam epitaxy
Authors: Zhang Ning , Nakamura Kotaro , Baba Masakazu , Toko Kaoru , Suemasu Takashi
Published: February 2014

a-Axis-oriented BaSi2 epitaxial films were grown on Si(111) by molecular beam epitaxy, and the diffusion coefficients of Sb and As were evaluated using secondary ion mass spectrometry (SIMS) with Cs+ ions. The SIMS profiles of these atoms were reproduced well by considering both the lattice and grain boundary (GB) diffusions. The temperature dependence of lattice and GB diffusion coefficients was determined from the SIMS profiles, and their activation energies were found to be 0.77 and 0.65 eV for Sb, and 0.91 and 0.88 eV for As, respectively.
Changes in Arctic melt season and implications for sea ice loss
Authors: Stroeve J. C. , Markus T. , Boisvert L. , Miller J. , Barrett A.
Published: February 2014

The Arctic‐wide melt season has lengthened at a rate of 5 days decade−1 from 1979 to 2013, dominated by later autumn freezeup within the Kara, Laptev, East Siberian, Chukchi, and Beaufort seas between 6 and 11 days decade−1. While melt onset trends are generally smaller, the timing of melt onset has a large influence on the total amount of solar energy absorbed during summer. The additional heat stored in the upper ocean of approximately 752 MJ m−2 during the last decade increases sea surface temperatures by 0.5 to 1.5 °C and largely explains the observed delays in autumn freezeup within the Arctic Ocean's adjacent seas. Cumulative anomalies in total absorbed solar radiation from May through September for the most recent pentad locally exceed 300–400 MJ m−2 in the Beaufort, Chukchi, and East Siberian seas. This extra solar energy is equivalent to melting 0.97 to 1.3 m of ice during the summer.
Crustal thinning in the northern Tyrrhenian Rift: Insights from multichannel and wide‐angle seismic data across the basin
Authors: Moeller S. , Grevemeyer I. , Ranero C. R. , Berndt C. , Klaeschen D. , Sallares V. , Zitellini N. , de Franco R.
Published: February 2014

Extension of the continental lithosphere leads to the formation of rift basins or rifted continental margins if breakup occurs. Seismic investigations have repeatedly shown that conjugate margins have asymmetric tectonic structures and different amount of extension and crustal thinning. Here we compare two coincident wide‐angle and multichannel seismic profiles across the northern Tyrrhenian rift system sampling crust that underwent different stages of extension from north to south and from the flanks to the basin center. Tomographic inversion reveals that the crust has thinned homogeneously from ~24 km to ~17 km between the Corsica Margin and the Latium Margin implying a β factor of ~1.3–1.5. On the transect 80 km to the south, the crust thinned from ~24 km beneath Sardinia to a maximum of ~11 km in the eastern region near the Campania Margin (β factor of ~2.2). The increased crustal thinning is accompanied by a zone of reduced velocities in the upper crust that expands progressively toward the southeast. We interpret that the velocity reduction is related to rock fracturing caused by a higher degree of brittle faulting, as observed on multichannel seismic images. Locally, basalt flows are imaged intruding sediment in this zone, and heat flow values locally exceed 100 mW/m2. Velocities within the entire crust range 4.0–6.7 km/s, which are typical for continental rocks and indicate that significant rift‐related magmatic underplating may not be present. The characteristics of the pre‐tectonic, syn‐tectonic and post‐tectonic sedimentary units allow us to infer the spatial and temporal evolution of active rifting. In the western part of the southern transect, thick postrift sediments were deposited in half grabens that are bounded by large fault blocks. Fault spacing and block size diminish to the east as crustal thinning increases. Recent tectonic activity is expressed by faults cutting the seafloor in the east, near the mainland of Italy. The two transects show the evolution from the less extended rift in the north with a fairly symmetric conjugate structure to the asymmetric margins farther south. This structural evolution is consistent with W‐E rift propagation and southward increasing extension rates.
Impact of satellite rainfall assimilation on Weather Research and Forecasting model predictions over the Indian region
Authors: Kumar Prashant , Kishtawal C. M. , Pal P. K.
Published: February 2014

Rainfall is probably the most important parameter that is predicted by numerical weather prediction models, though the skill of rainfall prediction is the poorest compared to other parameters, e.g., temperature and humidity. In this study, the impact of rainfall assimilation on mesoscale model forecasts is evaluated during Indian summer monsoon 2011. The Weather Research and Forecasting (WRF) model and its four‐dimensional variational data assimilation system are used to assimilate the Tropical Rainfall Measuring Mission 3B42 and Japan Aerospace Exploration Agency Global Satellite Mapping of Precipitation retrieved rainfall. A total of five experiments are performed daily with and without assimilation of rainfall data during the entire month of July 2011. Separate assimilation experiments are performed to assess the sensitivity of WRF model forecast with strict and less strict quality control. Assimilation of rainfall improves the forecast of temperature, specific humidity, and wind speed. Domain average improvement parameter of rainfall forecast is also improved over the Indian landmass when compared with NOAA Climate Prediction Center Morphing technique and Indian Meteorological Department gridded rainfall.
Stratospheric ozone response to sulfate geoengineering: Results from the Geoengineering Model Intercomparison Project (GeoMIP)
Authors: Pitari Giovanni , Aquila Valentina , Kravitz Ben , Robock Alan , Watanabe Shingo , Cionni Irene , Luca Natalia De , Genova Glauco Di , Mancini Eva , Tilmes Simone
Published: February 2014

Geoengineering with stratospheric sulfate aerosols has been proposed as a means of temporarily cooling the planet, alleviating some of the side effects of anthropogenic CO2 emissions. However, one of the known side effects of stratospheric injections of sulfate aerosols under present‐day conditions is a general decrease in ozone concentrations. Here we present the results from two general circulation models and two coupled chemistry‐climate models within the experiments G3 and G4 of the Geoengineering Model Intercomparison Project. On average, the models simulate in G4 an increase in sulfate aerosol surface area density similar to conditions a year after the Mount Pinatubo eruption and a decrease in globally averaged ozone by 1.1−2.1 DU (Dobson unit, 1 DU = 0.001 atm cm) during the central decade of the experiment (2040–2049). Enhanced heterogeneous chemistry on sulfate aerosols leads to an ozone increase in low and middle latitudes, whereas enhanced heterogeneous reactions in polar regions and increased tropical upwelling lead to a reduction of stratospheric ozone. The increase in UV‐B radiation at the surface due to ozone depletion is offset by the screening due to the aerosols in the tropics and midlatitudes, while in polar regions the UV‐B radiation is increased by 5% on average, with 12% peak increases during springtime. The contribution of ozone changes to the tropopause radiative forcing during 2040–2049 is found to be less than −0.1 W m−2. After 2050, because of decreasing ClOx concentrations, the suppression of the NOx cycle becomes more important than destruction of ozone by ClOx, causing an increase in total stratospheric ozone.
Least‐squares‐based adaptive target localization by mobile distance measurement sensors
Authors: Fidan Barış , Çamlıca Ahmet , Güler Samet
Published: February 2014

A least‐squares‐based adaptive algorithm with forgetting factor is proposed for localization of a target by a mobile distance measurement sensor. This problem, in its most general form, was tackled in a recent paper using a gradient adaptive algorithm, assuming distance measurements are directly available. We establish that the proposed algorithm bears the same stability and convergence properties as the gradient algorithm previously studied. It is demonstrated via simulations that the proposed algorithm converges significantly faster to the location estimates than the gradient algorithm for high forgetting factor values and significantly reduces the noise effects for small values of the forgetting factor. Furthermore, a more challenging form of the original problem is considered, where distance information is required to be deduced from time of flight measurements, considering a time of flight‐based active distance measurement sensor and an environment with unknown signal permittivity/speed; the proposed algorithm is redesigned to solve this problem. Copyright © 2014 John Wiley & Sons, Ltd.
Practical Iron‐Catalyzed Hydrogen Peroxide Epoxidation of Aromatic Olefins using a Combination of Two Kinds of Simple Picolinate Ligands under Halide‐Free Reaction Conditions
Authors: Chishiro Takefumi , Kon Yoshihiro , Nakashima Takuya , Goto Midori , Sato Kazuhiko
Published: February 2014

High‐yield syntheses of epoxides using an iron complex having two types of picolinates in the presence of hydrogen peroxide under halide‐free reaction conditions were achieved. The reaction is very simple. The complex, prepared with iron(II) acetate, 2‐picolinic acid (picH) and 6‐methyl‐2‐picolinic acid (Me‐picH) in acetonitrile, quickly catalyzed an epoxidation of styrene (15 min.) at 25 °C with 1.40 equivalents of 35% aqueous hydrogen peroxide solution to afford styrene oxide in 95% yield with 96% selectivity. We also carried out a 100‐g scale epoxidation of styrene using 1.25 equivalents of 35% aqueous hydrogen peroxide solution with the iron catalyst to give styrene oxide in 80% isolated yield. The developed iron catalyst was efficiently applicable to the epoxidation of various aromatic olefins to give the corresponding epoxides in high yields. To obtain more information about this catalytic system, the pre‐catalyst of this reaction was isolated and the structure was determined to be [Fe(pic)(Me‐pic)2] by single‐crystal X‐ray analysis. The [Fe(pic)(Me‐pic)2] catalyst effectively epoxidized styrene to styrene oxide in 93% yields. The system should be suitable for large‐scale preparations of aromatic olefins due to the employment of simple ligands with halide‐ and amine‐free reaction conditions.

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Hosts for High‐Performance Phosphorescent Organic Light‐Emitting Diodes Based on Carbazole Derivatives
Authors: Jiang Hongji
Published: February 2014

Organic electroluminescent (EL) materials have many advantages when compared with their inorganic counterparts and, therefore, they have a wide range of potential applications in communication, information display, illumination, and so on. Phosphorescent organic light‐emitting diodes (PHOLEDs) that contain late transition‐metal complexes as emitters are particularly attractive due to their ability to harvest singlet and triplet excitons, which makes it possible to achieve an internal quantum efficiency of 100 %. To suppress concentration quenching, a phosphorescent emitter is usually dispersed in a suitable host to obtain a high photoluminescent quantum yield. Developing a host with a suitable triplet energy level, charge‐transporting ability, and thermal and film stability is thus the key to improving the performance of PHOLEDs. Carbazole‐based chromophores are widely used in the synthesis of highly efficient hosts for PHOLEDs. However, these compounds are not universal or unique segments for constructing high performance hosts. Herein, up‐to‐date methods for chemical modifications to obtain hosts for high‐performance PHOLEDs based on carbazole derivatives are presented in detail. These methods include heterocycle replacement and extension of the conjugated structure of the carbazole skeleton. Finally, some issues to be addressed and hotspots to be further investigated are also discussed.
Research and in situ conservation of owl monkeys enhances environmental law enforcement at the Colombian‐Peruvian border
Authors: Maldonado Angela M. , Peck Mika R.
Published: February 2014

This study reports on impacts of illegal trade in owl monkeys (Aotus nancymaae,A. vociferans) for the biomedical research market in the Colombian‐Peruvian Amazonian border. Through freedom of information requests and interviews with hunters we found that 912 owl monkeys, includingA. nancymaaecaptured in Peru, were trapped over a 3‐month period in 2012 to supply a malaria research facility based in Leticia, Colombia, which had trapping permits for the use of only 800A. vociferansannually yet experimentation took place usingA. nancymaae. High levels of extraction in Peru have had population‐level impacts with significantly lower densities ofAotusspp. (3–24 individuals/km2) compared to Colombian sites with low hunting pressure (26–44 individuals/km2). Post‐experimental release of this species in Colombian territory has created a new distribution whose status and impacts on resident populations ofA. vociferansremain unknown. The trapping method has also had environmental impact, with loss of over 65,000 trees (including sleeping sites), annually. AsAotusspecies are registered under the Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II, international trade requires official permission and evidence that extraction does not impact wild populations. However, no official records exist and CITES legislation has failed, due principally to a lack of appropriate monitoring by national authorities responsible for compliance. Of further concern is that we had previously documented and reported the illegal trade to the appropriate governmental authorities yet still no action was taken—as demonstrated by the continuing trade in 2013. Enforcement eventually occurred when a non‐governmental organization initiated legal action against organizations responsible. A successful second instance ruling by the Colombian State's Council in 2013 revoked trapping permits. Using the trade in owl monkeys as a case study we consider implementation, compliance, and enforcement of CITES in the border area to identify mechanisms to improve enforcement of environmental legislation. Am. J. Primatol. 76:658–669, 2014. © 2014 Wiley Periodicals, Inc.
Glossar von Begriffen zur Assoziatbildung und Selbstorganisation in den Polymerwissenschaften (IUPAC‐Empfehlung 2013)
Authors: Schmuck Carsten , Keilitz Juliane
Published: February 2014

Die Konstruktion faszinierender Molekülarchitekturen in der supramolekularen Chemie wurde durch ein breiteres Verständnis der molekularen Selbstorganisation erleichtert, wobei die Methoden der Polymerwissenschaft eine große Rolle beim Erreichen dieser Fortschritte spielten. Dies hatte aber auch eine sich schnell erweiternde Terminologie zur Folge, wobei alte Begriffe neue Bedeutung erhalten und neue Begriffe je nach Bedarf entstehen. Diese Zusammenstellung soll hier für mehr Klarheit sorgen.
Potential‐Driven Chirality Manifestations and Impressive Enantioselectivity by Inherently Chiral Electroactive Organic Films
Authors: Sannicolò Francesco , Arnaboldi Serena , Benincori Tiziana , Bonometti Valentina , Cirilli Roberto , Dunsch Lothar , Kutner Włodzimierz , Longhi Giovanna , Mussini Patrizia R. , Panigati Monica , Pierini Marco , Rizzo Simona
Published: February 2014

The typical design of chiral electroactive materials involves attaching chiral pendants to an electroactive polyconjugated backbone and generally results in modest chirality manifestations. Discussed herein are electroactive chiral poly‐heterocycles, where chirality is not external to the electroactive backbone but inherent to it, and results from a torsion generated by the periodic presence of atropisomeric, conjugatively active biheteroaromatic scaffolds, (3,3′‐bithianaphthene). As the stereogenic element coincides with the electroactive one, films of impressive chiroptical activity and outstanding enantiodiscrimination properties are obtained. Moreover, chirality manifestations can be finely and reversibly tuned by the electric potential, as progressive injection of holes forces the two thianaphthene rings to co‐planarize to favor delocalization. Such deformations, revealed by CD spectroelectrochemistry, are elastic and reversible, thus suggesting a breathing system.
Synthesis and solar cells applications of EO‐PF‐DTBT polymer
Authors: Zhou Lina , Bao Xichang , Liu Qian , Yu Jieliang , Chen Yanhua , Yang Renqiang , Sun Mingliang
Published: February 2014

Poly{[2,7‐(9,9‐bis‐(1‐(2‐(2‐methoxyethoxy)ethoxy)ethyl)‐fluorene)]‐alt‐[5,5‐(4,7‐di‐2′‐thienyl‐2,1,3‐benzothiadiazole)]} (EO‐PF‐DTBT) was synthesized by Suzuki coupling reaction. The polymer is soluble in common organic solvent, such as toluene, THF, and chloroform, and it also shows solubility in polar solvent, such as cyclopentanone. Solar cells based on EO‐PF‐DTBT and PC61BM show maximum power conversion efficiency of 2.65% with an open circuit voltage (VOC) of 0.86 V, a short circuit current density (JSC) of 6.10 mA/cm2, and a fill factor of 51% under AM 1.5G illumination at 100 mW/cm2, which is the best results for fluorene and 4,7‐di‐2‐thienyl‐2,1,3‐benzothiadiazole copolymers and PC61BM blend. The 1,8‐diiodooctane can work well to reduce the over‐aggregated phase structure in polymer solar cells. Our results suggest that the introducing high hydrophilic side chain into conjugated polymer donor materials can tune the aggregation structure and improve the solar cells performances. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40478.
Morphological analysis of crease patterns formed on surface‐attached hydrogel with a gradient in thickness
Authors: Kim Jungwook
Published: February 2014

The morphology of crease pattern formed on the surface‐attached hydrogel with a gradient in thickness is analyzed. We label the hydrogel surface at the creased state with fluorescent polyelectrolyte, which enables us to visualize surface morphology of creases using the fluorescent microscopy. Various morphological features of crease patterns are analyzed at different thickness of hydrogel, or characteristic spacing of creases λc,max, to examine the self‐similarity of crease morphology at different length scales. Some morphological features show no λc,max dependence, implying the self‐similarity, while others show weak λc,max dependence with positive values of the exponent of power law fit for the plots. We infer that such nonself‐similarity is originated from the variations in the kinetics of swelling and creasing of hydrogel, the effect of surface tension, or the reduction in the osmotic pressure occurred during the polyelectrolyte labeling step at different λc,max. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40482.
Recovery potential of smalltooth sawfish, Pristis pectinata, in the United States determined using population viability models
Authors: Carlson John K. , Simpfendorfer Colin A.
Published: February 2014

Determining the recovery potential of endangered species is an important component for developing strategies necessary to return populations to healthy levels. Many species of endangered marine animals have been regarded as having low productivity and therefore, an inherent inability to rapidly recover from severe depletion.

An age‐structured Leslie matrix model was constructed for the US population of smalltooth sawfish, Pristis pectinata, to determine their ability to recover under scenarios using different life history inputs and the effects of bycatch mortality and catastrophes.

Population growth was highest (λ=1.237 yr‐1) when age‐at‐maturity was 7 yr and decreased to 1.150 yr‐1 when age‐at‐maturity was 11 yr.

Despite a high level of variability throughout the model runs, in the absence of fishing mortality or climate catastrophic effects the population grew at a relatively rapid rate approaching carrying capacity in 40 or 50 yr when the initial population was 600 or 2250 females, respectively. Population projections under various levels of fishing mortality resulted in extinction when mortality was highest, initial population size was small, and age‐at‐maturity was 11 yr. Scenarios testing the potential effects of extreme cold exposure showed little difference to those scenarios testing the effects of fishing mortality.

Using the optimistic estimates of population size, lower age‐at‐maturity and the lower level of fisheries‐related mortality, smalltooth sawfish in US waters appear to have the ability to recover within the foreseeable future. Effective management and recovery of this species can only be achieved by keeping fishing‐related mortality low.

Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis, Biological Evaluation, and Docking Studies of New 2‐Furylbenzimidazoles as Anti‐Angiogenic Agents: Part II
Authors: Temirak Ahmed , Shaker Yasser M. , Ragab Fatma A. F. , Ali Mamdouh M. , Soliman Salwa M. , Mortier Jeremie , Wolber Gerhard , Ali Hamed I. , Diwani Hoda I. El
Published: February 2014

The 2‐(5‐methyl‐2‐furyl)‐1H‐benzimidazole moiety has shown promising activity against vascular endothelial growth factor (VEGF)‐induced angiogenesis. In part I of this study, we have synthesized new analogs and tested their anti‐angiogenic potentials. Here, we continue our previous study with different new analogs. Some compounds show promising cytotoxic activity against the human breast cancer cell line MCF‐7, with IC50 in the range of 7.80–13.90 µg/mL, and exhibited remarkable in vitro inhibition against VEGF in the MCF‐7 cancer cell line, with 95–98% of inhibition in comparison to tamoxifen as reference (IC50: 8.00 µg/mL, % of inhibition = 98%). Additionally, a molecular docking study was carried out to gain insight into plausible binding modes and to understand the structure–activity relationships of the synthesized compounds.
Hydrogen‐Bond and Metal–Ligand Coordination Bond Hybrid Supramolecular Capsules: Identification of Hemicapsular Intermediate and Dual Control of Guest Exchange Dynamics
Authors: Nito Yuki , Adachi Hirofumi , Toyoda Naoaki , Takaya Hikaru , Kobayashi Kenji , Yamanaka Masamichi
Published: February 2014

Hybrid supramolecular capsules self‐assemble by simultaneously forming hydrogen and metal–ligand coordination bonds on mixing a C2‐symmetrical cavitand (calix[4]resorcinarene‐based cavitands with ureide and terminal 4‐pyridyl units) with platinum or palladium complexes ([Pt(OTf)2] or [Pd(OTf)2] with chelating bisphosphines) in 1:1 ratio. Hemicapsular assemblies formed in the presence of excess amounts of cavitand relative to the platinum or palladium complexes are identified as intermediates in the above self‐assembly process by 2D‐NOESY spectroscopy. External‐anion‐assisted encapsulation of a neutral guest, 4,4′‐diiodobiphenyl, inside the hybrid supramolecular capsules accompanied conformational changes in the hydrogen‐bonding moieties. The in/out exchange ratio of the encapsulated guest depends on the bite angle of the bisphosphine ligand. Addition of DMSO accelerates guest exchange by weakening the hydrogen bonds in the encapsulation complex. Therefore, variations in the structure of the metal complex and amount of polar solvent exert dual control on the dynamics of the guest exchange.
Metabolism of methylstenbolone studied with human liver microsomes and the uPA+/+‐SCID chimeric mouse model
Authors: Geldof Lore , Lootens Leen , Polet Michael , Eichner Daniel , Campbell Thane , Nair Vinod , Botrè Francesco , Meuleman Philip , Leroux‐Roels Geert , Deventer Koen , Eenoo Peter Van
Published: February 2014

Anti‐doping laboratories need to be aware of evolutions on the steroid market and elucidate steroid metabolism to identify markers of misuse. Owing to ethical considerations, in vivo and in vitro models are preferred to human excretion for nonpharmaceutical grade substances. In this study the chimeric mouse model and human liver microsomes (HLM) were used to elucidate the phase I metabolism of a new steroid product containing, according to the label, methylstenbolone. Analysis revealed the presence of both methylstenbolone and methasterone, a structurally closely related steroid. Via HPLC fraction collection, methylstenbolone was isolated and studied with both models. Using HLM, 10 mono‐hydroxylated derivatives (U1–U10) and a still unidentified derivative of methylstenbolone (U13) were detected. In chimeric mouse urine only di‐hydroxylated metabolites (U11–U12) were identified. Although closely related, neither methasterone nor its metabolites were detected after administration of isolated methylstenbolone. Administration of the steroid product resulted mainly in the detection of methasterone metabolites, which were similar to those already described in the literature. Methylstenbolone metabolites previously described were not detected. A GC‐MS/MS multiple reaction monitoring method was developed to detect methylstenbolone misuse. In one out of three samples, previously tested positive for methasterone, methylstenbolone and U13 were additionally detected, indicating the applicability of the method. Copyright © 2014 John Wiley & Sons, Ltd.
More than just a Halogenase: Modification of Fatty Acyl Moieties by a Trifunctional Metal Enzyme
Authors: Pratter Sarah M. , Ivkovic Jakov , Birner‐Gruenberger Ruth , Breinbauer Rolf , Zangger Klaus , Straganz Grit D.
Published: February 2014

The highly selective oxidative halogenations by non‐heme iron and α‐ketoglutarate‐dependent enzymes are key reactions in the biosynthesis of lipopeptides, and often bestow valuable bioactivity to the metabolites. Here we present the first biochemical characterization of a putative fatty acyl halogenase, HctB, which is found in the hectochlorin biosynthetic pathway of Lyngbya majuscula. Its unprecedented three‐domain structure, which includes an acyl carrier protein domain, allows self‐contained conversion of the covalently tethered hexanoyl substrate. Structural analysis of the native product by 13C NMR reveals high regioselectivity but considerable catalytic promiscuity. This challenges the classification of HctB as a primary halogenase: along with the proposed dichlorination, HctB performs oxygenation and an unprecedented introduction of a vinyl‐chloride moiety into the nonactivated carbon chain. The relaxed substrate specificity is discussed with reference to a molecular model of the enzyme–substrate complex. The results suggest that fatty acyl transformation at the metal center of HctB can bring about considerable structural diversity in the biosynthesis of lipopeptides.
Difference of neointimal growth patterns in bifurcation lesions among four kinds of drug‐eluting stents
Authors: Yoshimura Takahiro , Tanaka Akihiro , Mori Naoki , Nakamura Daisuke , Taniike Masayuki , Makino Nobuhiko , Egami Yasuyuki , Shutta Ryu , Tanouchi Jun , Nishino Masami
Published: February 2014

Aim: Neointimal proliferation of bifurcation lesions after implantation of drug‐eluting stents (DES) has not been well evaluated. Thus, we compared neointimal proliferation of bifurcation lesions among four DES using optical coherence tomography (OCT). Methods: 8‐month follow‐up OCT was performed in 68 bifurcation lesions treated by 15 sirolimus‐eluting stents (SES) and 17 paclitaxel‐eluting stents (PES) as first‐generation DES, and by 17 zotarolimus‐eluting stents (ZES) and 19 everolimus‐eluting stents (EES) as second‐generation DES. Cross‐sectional images of the bifurcation lesion using OCT were analyzed every 450 µm. All images were divided into three areas: inner wall of the bifurcation (IB), outer wall of the bifurcation (OB), and ostium of the side branch (SB). We compared the incidence of uncovered struts (IUS) among three areas and the averaged neointimal thickness (NIH) between IB and OB in each stent and also compared these OCT parameters among all DES. Results: There were no significant differences of IUS between IB and OB in second‐generation DES, while in first‐generation DES, IUS of IB and OB showed significant differences. The IUS of SES in both areas was significantly higher than in the other DES (all P < 0.001). PES had a significantly higher IUS in SB than the others (all P < 0.001). NIH of OB was significantly higher than that of IB in PES, ZES, and EES, but in SES the NIH was similar in the two areas. Conclusions: OCT revealed different neointimal growth patterns among SES, PES, ZES, and EES in bifurcation lesions. © 2014 Wiley Periodicals, Inc.
Arrays of Screen‐Printed Graphite Microband Electrodes as a Versatile Electroanalysis Platform
Authors: Vagin Mikhail Yu. , Sekretaryova Alina N. , Reategui Rafael Sanchez , Lundstrom Ingemar , Winquist Fredrik , Eriksson Mats
Published: February 2014

Arrays of microband electrodes were developed by screen printing followed by cutting, which enabled the realization of microband arrays at the cut edge. The microband arrays of different designs were characterized by physical and electrochemical methods. In both cases, the methods showed that the microband width was around 5 μm. Semi‐steady‐state cyclic voltammetry responses were observed for redox probes, and chronocoulometric measurements showed the establishment of convergent diffusion regimes characterized by current densities similar to those of a single microelectrode. The analytical performance of the electrode system and its versatility were illustrated with two electrochemical assays: detection of ascorbic acid through direct oxidation and a mediated glucose biosensor fabricated by dip coating. Due to convergent mass transport, both systems showed an enhancement in their analytical characteristics. The developed approach can be adapted to automated electrode recovery.
Polymeric Carbon Nitride/Mesoporous Silica Composites as Catalyst Support for Au and Pt Nanoparticles
Authors: Xiao Ping , Zhao Yanxi , Wang Tao , Zhan Yingying , Wang Huihu , Li Jinlin , Thomas Arne , Zhu Junjiang
Published: February 2014

Small and homogeneously dispersed Au and Pt nanoparticles (NPs) were prepared on polymeric carbon nitride (CNx)/mesoporous silica (SBA‐15) composites, which were synthesized by thermal polycondensation of dicyandiamide‐impregnated preformed SBA‐15. By changing the condensation temperature, the degree of condensation and the loading of CNx can be controlled to give adjustable particle sizes of the Pt and Au NPs subsequently formed on the composites. In contrast to the pure SBA‐15 support, coating of SBA‐15 with polymeric CNx resulted in much smaller and better‐dispersed metal NPs. Furthermore, under catalytic conditions the CNx coating helps to stabilize the metal NPs. However, metal NPs on CNx/SBA‐15 can show very different catalytic behaviors in, for example, the CO oxidation reaction. Whereas the Pt NPs already show full CO conversion at 160 °C, the catalytic activity of Au NPs seems to be inhibited by the CNx support.
Bioinspired Intramolecular Diels–Alder Reaction: A Rapid Access to the Highly‐Strained Cyclopropane‐Fused Polycyclic Skeleton
Authors: Zhu Shifa , Guo Zhengjiang , Huang Zhipeng , Jiang Huanfeng
Published: February 2014

A bioinsipred gold‐catalyzed tandem Diels–Alder/Diels–Alder reaction of an enynal and a 1,3‐diene, forming the highly‐strained benzotricyclo[3.2.1.02,7]octane skeleton, was reported. In contrast, a Diels–Alder/Friedel–Crafts tandem reaction occurred instead when silver salts were used as the catalyst. Although both reactions experienced the similar Diels–Alder reaction of a pyrylium intermediate with a 1,3‐diene, they have different reaction mechanisms. The former proceeded with a stepwise Diels–Alder reaction, while the latter one with a concerted one.
Chiral Discrimination of Ofloxacin Enantiomers Using DNA Double Helix Regulated by Metal Ions
Authors: Fu Yan , Duan Xiaoli , Chen Xiongfei , Zhang Haixiang , Zhang Jinli , Li Wei
Published: February 2014

DNA‐based chiral selectors are constructed to discriminate ofloxacin enantiomers through metal‐ion anchoring on a special DNA double helix that contains successive GC pairs. The effects of metal ions involving Mg2+, Ni2+, Cu2+, Ag+, and Pt2+ were studied on the regulation of DNA chiral discrimination towards ofloxacin enantiomers. It is shown that DNA‐Cu(II) complexes exhibit the highest enantioselectivities at the [Cu2+]/base ratio of 0.1. The enantiomeric excess can reach 59% in R‐enantiomer after being adsorbed by the RET‐Cu(II) complex. Stereoselective recognition of ofloxacin enantiomers on the double helix is tunable via external stimulus, providing a programmable desorption process to regenerate DNA. This DNA‐based chiral selector exhibits excellent reusability without apparent loss of enantioselectivity after three cycles of adsorption and desorption. Chirality 26:249–254, 2014. © 2014 Wiley Periodicals, Inc.
Bioraffinerien
Authors: Peters Dietmar , Ulber Roland , Wagemann Kurt
Published: February 2014

Die Entwicklung von Bioraffinerien gilt als ein wichtiger Bestandteil zur Lösung zukünftiger globaler Herausforderungen wie etwa die Versorgung einer wachsenden Weltbevölkerung, die Endlichkeit fossiler Ressourcen, oder der Umwelt‐ und Klimaschutz. Bioraffinerien versprechen hohe Effizienz und Nachhaltigkeit bei der stofflichen und energetischen Nutzung von Biomasse, indem sie verschiedene Prozesse integrieren. Bevor Bioraffinerien kommerziell betrieben werden können, besteht jedoch noch erheblicher Forschungsbedarf. Dies betrifft die Integration verschiedener Verfahren zu kohärenten technischen Konzepten, die Hochskalierung vom Labor‐ zum Industriemaßstab, die Rohstoffversorgung, die Optimierung der Verfahren und Produkte der Primär‐ und Sekundärraffination, gerade auch unter dem Gesichtspunkt der Nachhaltigkeit. Die deutsche Roadmap Bioraffinerien erfasst systematisch den aktuellen Stand der Bioraffineriekonzepte, analysiert sie nach ökonomischen und ökologischen Kriterien und gibt konkrete Handlungsempfehlungen für Forschung & Entwicklung. Sie gibt einen umfassenden Überblick über verschiedene Technologien und über die Wege zu ihrer Realisierung. Ziel der Roadmap Bioraffinerien ist es, bis 2030 möglichst effiziente, bedarfsgerechte und ökolo‐gisch vorteilhafte Bioraffinerie‐Konzepte zu entwickeln und zu betreiben.
Bromodomains and Their Pharmacological Inhibitors
Authors: Gallenkamp Daniel , Gelato Kathy A. , Haendler Bernard , Weinmann Hilmar
Published: February 2014

Over 60 bromodomains belonging to proteins with very different functions have been identified in humans. Several of them interact with acetylated lysine residues, leading to the recruitment and stabilization of protein complexes. The bromodomain and extra‐terminal domain (BET) proteins contain tandem bromodomains which bind to acetylated histones and are thereby implicated in a number of DNA‐centered processes, including the regulation of gene expression. The recent identification of inhibitors of BET and non‐BET bromodomains is one of the few examples in which effective blockade of a protein–protein interaction can be achieved with a small molecule. This has led to major strides in the understanding of the function of bromodomain‐containing proteins and their involvement in diseases such as cancer and inflammation. Indeed, BET bromodomain inhibitors are now being clinically evaluated for the treatment of hematological tumors and have also been tested in clinical trials for the relatively rare BRD‐NUT midline carcinoma. This review gives an overview of the newest developments in the field, with a focus on the biology of selected bromodomain proteins on the one hand, and on reported pharmacological inhibitors on the other, including recent examples from the patent literature.
A phase 2 trial of dacomitinib (PF‐00299804), an oral, irreversible pan‐HER (human epidermal growth factor receptor) inhibitor, in patients with advanced non–small cell lung cancer after failure of prior chemotherapy and erlotinib
Authors: Reckamp Karen L. , Giaccone Giuseppe , Camidge D. Ross , Gadgeel Shirish M. , Khuri Fadlo R. , Engelman Jeff A. , Koczywas Marianna , Rajan Arun , Campbell Alicyn K. , Gernhardt Diana , Ruiz‐Garcia Ana , Letrent Stephen , Liang Jane , Taylor Ian , O'Connell Joseph P. , Jänne Pasi A.
Published: February 2014

BACKGROUND

This phase 2 trial (ClinicalTrials.gov identifier NCT00548093) assessed the efficacy, safety, and impact on health‐related quality of life of dacomitinib (PF‐00299804), an irreversible tyrosine kinase inhibitor (TKI) of human epidermal growth factor receptors (EGFR)/HER1, HER2, and HER4, in patients with KRAS wild‐type non–small cell lung cancer (NSCLC).

METHODS

Patients with advanced NSCLC, progression on 1 or 2 regimens of chemotherapy and erlotinib, KRAS wild‐type or known EGFR‐sensitizing mutant tumor, and Eastern Cooperative Oncology Group performance status of 0 to 2 received 45 mg of dacomitinib once daily continuously in 21‐day cycles.

RESULTS

A total of 66 patients enrolled (adenocarcinoma, n = 50; those without adenocarcinoma [nonadenocarcinoma], n = 16). The objective response rate (ORR) for patients with adenocarcinoma (primary endpoint) was 5% (2 partial responses; 1‐sided P = .372 for null hypothesis [H0]: ORR ≤ 5%) and 6% (1 partial response) for patients with nonadenocarcinoma. Responders included: 2 of 25 EGFR mutation‐positive tumors; 1 of 3 EGFR wild‐type with HER2 amplification. Median progression‐free survival was 12 weeks overall (n = 66) and 18 weeks (n = 26) for patients with EGFR mutation‐positive tumors. Common treatment‐related adverse events were of grade 1 or 2 severity, manageable with standard supportive care, and included diarrhea (grade 3 [G3], 12%), acneiform dermatitis (G3, 6%), exfoliative rash (G3, 3%), dry skin (G3, 0%), fatigue (G3, 3%), and stomatitis (G3, 2%). Six patients (9%) discontinued due to treatment‐related adverse events. By patient report, NSCLC symptoms of dyspnea, cough, and pain (chest, arm/shoulder) showed improvement first observed after 3 weeks on therapy.

CONCLUSIONS

Dacomitinib demonstrated preliminary activity and acceptable tolerability in heavily pretreated patients, and may offer benefit in molecularly defined patient subsets. Cancer 2014;120:1145–1154. © 2014 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.
Impact of tyrosine kinase inhibitors on minimal residual disease and outcome in childhood Philadelphia chromosome‐positive acute lymphoblastic leukemia
Authors: Jeha Sima , Coustan‐Smith Elaine , Pei Deqing , Sandlund John T. , Rubnitz Jeffrey E. , Howard Scott C. , Inaba Hiroto , Bhojwani Deepa , Metzger Monika L. , Cheng Cheng , Choi John K. , Jacobsen Jeffrey , Shurtleff Sheila A. , Raimondi Susana , Ribeiro Raul C. , Pui Ching‐Hon , Campana Dario
Published: February 2014

BACKGROUND

Breakpoint cluster region‐Abelson murine leukemia viral oncogene homolog 1 (BCR‐ABL1) tyrosine kinase inhibitors (TKIs) improve the outcome of patients with childhood Philadelphia chromosome (Ph)‐positive acute lymphoblastic leukemia (ALL) when they are incorporated into postremission induction chemotherapy. To date, no data are available on the impact of TKIs on minimal residual disease (MRD) at the end of induction therapy among patients who have a poor early response to 2 weeks of induction therapy that does not include TKIs.

METHODS

The authors analyzed the early response to TKIs during remission induction in children with Ph‐positive ALL who were treated at St. Jude Children's Research Hospital. MRD was measured on days 15 and 42 of induction. TKIs were incorporated into induction therapy on day 22 in the post‐TKI era.

RESULTS

TKIs produced a marked drop in MRD levels: at the end of remission induction, 9 of 11 patients who received imatinib or dasatinib and conventional induction chemotherapy achieved MRD‐negative status compared with only 2 of 16 patients who received chemotherapy alone (P < .001). The 5‐year event‐free survival rate (± standard deviation) was 68.6% ± 19.2% for the 11 patients who received TKIs versus 31.6% ± 9.9% for the 19 patients who did not (P = .022); notably, 2 of the former group underwent hematopoietic stem cell transplantation versus 15 of the latter group (P = .002). MRD levels and outcomes did not differ significantly among 498 patients with standard‐risk/high‐risk, Ph‐negative ALL who were treated in the pre‐TKI or post‐TKI eras.

CONCLUSIONS

TKIs administered in the early phases of therapy can dramatically reduce MRD and improve the outcome of childhood Ph‐positive ALL. Cancer 2014;120:1514–1519. © 2014 American Cancer Society.
Parallel resolution of the 3D Helmholtz equation based on multi‐graphics processing unit clusters
Authors: Ortega Gloria , Lobera Julia , García Inmaculada , Pilar Arroyo M. , Garzón Ester M.
Published: February 2014

The resolution of the 3D Helmholtz equation is required in the development of models related to a wide range of scientific and technological applications. For solving this equation in complex arithmetic, the biconjugate gradient (BCG) method is one of the most relevant solvers. However, this iterative method has a high computational cost because of the large sparse matrix and the vector operations involved. In this paper, a specific BCG method, adapted for the regularities of the Helmholtz equation is presented. This BCG is based on the implementation of a novel format (named ‘Regular Format’) that allows the storage of the large sparse matrix involved in the sparse matrix vector product in a compact form. The contribution of this work is twofold: (1) decreasing the memory requirements of the 3D Helmholtz equation using the ‘Regular Format’ and (2) speeding up the resolution of the equation using high performance computing resources. A hybrid Message Passing Interface (MPI)‐graphics processing unit CUDA GPU parallelization that is capable of solving complex problems in short time has carried out (Fast‐Helmholtz). Fast‐Helmholtz combines optimizations at Message Passing Interface and GPU levels to reduce communications costs and to improve the exploitation of GPU architecture. This strategy makes it possible to extend the dimension of the Helmholtz problem to be solved, thanks to the relevant reduction of memory requirements and runtime. Copyright © 2014 John Wiley & Sons, Ltd.