bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of suspended normal-metal-type tunneling junction refrigerator
Authors: Kashiwaya Satoshi , Kashiwaya Hiromi , Koyanagi Masao , Tanaka Yukio
Published: August 2016

We have developed a suspended normal-metal-type superconducting-normal metal-superconductor tunneling junction refrigerator for the cooling of highly sensitive sensors operating at ultralow temperatures. The performance of the refrigerator is evaluated by comparing the experimental conductance with the numerical results of a theoretical formulation. The lowest temperature of 0.093 K at a bath temperature of 0.334 K indicates the successful operation of the refrigerator. The maximum cooling power of the present refrigerator estimated on the basis of the nonequilibrium stationary state model is 213 pW for a junction area of 40 × 7 µm2.
El potencial de la maricultura de laminarias como fuente para la obtención de biocombustibles y otros bioproductos en la costa atlántica de España
Authors: Peteiro César , Prado óscar J. , García-Tasende Manuel
Published: August 2016

Las macroalgas marinas contienen polisacáridos, lípidos y proteínas, entre otros componentes orgánicos, que se pueden utilizar para producir diferentes biocarburantes. Sin embargo, la producción de bioetanol es el que ha despertado actualmente un mayor interés por el alto contenido de polisacáridos (40-75% de su peso seco) que presentan algunas grandes algas conocidas con el nombre de laminarias. Estas macroalgas marinas pueden utilizarse para la producción de bioetanol mediante un proceso de hidrólisis y fermentación de sus polisacáridos que ha sido mejorado recientemente para su aplicación industrial. Las laminarias ya se utilizan comercialmente para consumo humano, extracción de compuestos con múltiples aplicaciones industriales, pienso y forraje de animales y fertilizante. En este contexto, la acuicultura marina de laminarias en la costa atlántica de España puede constituir una fuente renovable, sostenible, limpia de biomasa para la obtención de bioetanol, además de otros productos con valor comercial. Su cultivo tendría importantes beneficios económicos pero también ambientales, al reciclar carbonos atmosféricos y nutrientes inorgánicos del medio marino. En la presente revisión se presenta una visión del proceso de producción de bietanol a partir de biomasa de laminarias y se discute el potencial de la maricultura de laminarias como fuente para producir bioetanol y otros bio-productos de valor en base a experiencias en la costa atlántica de España.
Baroclinic mixing of potential vorticity as the principal sharpening mechanism for the extratropical Tropopause Inversion Layer
Authors: Wang Shu Meir , Geller Marvin A.
Published: August 2016

Previous works have shown that a dry, idealized general circulation model could produce many features of the extratropical Tropopause Inversion Layer (TIL). In particular, the following have been shown, but no explanations were given for these results. (1) A sharper extratropical TIL resulted more from increased horizontal resolution than from increased vertical resolution. (2) If the Equator‐to‐Pole temperature gradient was varied, the annual variation of the extratropical TIL found in observations could be reproduced. (3) The extratropical TIL altitude showed excellent correlation with the upper tropospheric relative vorticity, as had been previously proposed. (4) Increased horizontal model resolutions led to extratropical TILs that were at lower altitudes. We show that these conclusions follow from baroclinic mixing of high stratospheric potential vorticity into the troposphere being the principal sharpening mechanism for the extratropical TIL and the increased baroclinic activity occurring in higher horizontal resolution models. We furthermore suggest that the distance from the jet exerts a greater influence on the height and sharpness of the extratropical TIL than does the upper tropospheric relative vorticity, and this accounts for the annual behavior of the extratropical TIL found in observations and reproduced with a dry, mechanistic, global model.
Simulated response of the mid‐Holocene Atlantic meridional overturning circulation in ECHAM6‐FESOM/MPIOM
Authors: Shi Xiaoxu , Lohmann Gerrit
Published: August 2016

Changes of the Atlantic meridional overturning circulation (AMOC) in the mid‐Holocene compared to the preindustrial state are explored in different coupled climate models. Using time‐slice integrations by a newly developed global finite‐element model ECHAM6‐FESOM with unstructured mesh and high resolution, our simulations show an enhanced mid‐Holocene AMOC, accompanied by an increase in the ocean salinity over regions of deep water formation. We identify two different processes affecting the AMOC: (1) a more positive phase of North Atlantic Oscillation (NAO) increased water density over the Labrador Sea through anomalous net evaporation and surface heat loss; (2) a decreased import of sea ice from the Arctic causes a freshwater reduction in the northern North Atlantic Ocean. Using the coupled model ECHAM6‐MPIOM in T63GR15 and T31GR30 grids, we find that the simulated AMOC has significant discrepancy with different model resolutions. In detail, stronger‐than‐present mid‐Holocene AMOC is revealed by simulations with the T63GR15 grid, which resembles the result of ECHAM6‐FESOM, while a decline of the mid‐Holocene AMOC is simulated by the low resolution model with the T31GR30 grid. Such discrepancy can be attributed to different changes in Labrador Sea density which is mainly affected by (1) NAO‐induced net precipitation and deep water convection, (2) freshwater transport from the Arctic Ocean, and (3) the strength of AMOC itself. Finally, we analyzed available coupled climate models showing a diversity of responses of AMOC to mid‐Holocene forcings, most of which reveal positive AMOC changes related to northern high latitudes salinification.
Diagnosing nonlinearities in the local and remote responses to partial Amazon deforestation
Authors: Badger Andrew M. , Dirmeyer Paul A.
Published: August 2016

Using a set of fully coupled climate model simulations, the response to partial deforestation over the Amazon due to agricultural expansion has been analyzed. Three variations of 50% deforestation (all of western half, all of eastern half, and half of each grid box) were compared with total deforestation to determine the degree and character of nonlinearity of the climate response to partial deforestation. A metric is developed to quantify the degree and distribution of nonlinearity in the response, applicable to any variable. The metric also quantifies whether the response is saturating or accelerating, meaning significantly either more or less than 50% of the simulated response to total deforestation is attained at 50% deforestation. The spatial structure of the atmospheric response to Amazon deforestation reveals large areas across the tropics that exhibit a significant nonlinear component, particularly for temperature and geopotential height. Over the domain between 45°S and 45°N across all longitudes, 50% deforestation generally provides less than half of the total response to deforestation over oceans, indicating the marine portion of climate system is somewhat resilient to progressive deforestation. However, over continents there are both accelerating and saturating responses to 50% Amazon deforestation, and the response is different depending on whether the eastern or western half of Amazonia is deforested or half of the forest is removed uniformly across the region.
Asymmetry and nonlinearity of the influence of ENSO on the northern winter stratosphere: 1. Observations
Authors: Rao Jian , Ren Rongcai
Published: August 2016

The El Niño–Southern Oscillation (ENSO) has significant effects on the extratropical stratosphere. This study explores the nonlinearity and the asymmetry of these influences by distinguishing the different effects of four types of ENSO: “moderate El Niño,” “strong El Niño,” “moderate La Niña,” and “strong La Niña.” It is revealed that the moderate El Niño and the strong La Niña are much more efficient than the strong El Niño and the moderate La Niña, respectively, in modulating the northern winter stratospheric variability, resulting in significant nonlinearity and asymmetry. The tropical rainfall anomalies induced by a moderate El Niño or a strong La Niña are centered over the central equatorial Pacific region near the dateline, while the convection responses to a strong El Niño or a moderate La Niña are centered farther eastward. Accordingly, the anomalous Pacific‐North America wave train pattern is modulated by ENSO in a nonlinear and asymmetric way, which leads to the large nonlinear and asymmetric components of the vertical Eliassen‐Palm (E‐P) flux responses to ENSO. The increase of planetary wave activity in the extratropical stratosphere in moderate El Niño winters is thus greater than in strong El Niño winters, whereas a strong La Niña gives a larger decrease in propagation than a moderate La Niña. The relatively strong (weak) E‐P flux responses to moderate (strong), El Niño and strong (moderate) La Niña explains the remarkable nonlinearity and asymmetry in the response of the extratropical stratosphere to ENSO.
Commentary on accessing 3‐D currents in space: Experiences from Cluster
Authors: Dunlop M. W. , Haaland S. , Escoubet P. C. , Dong X.‐C.
Published: August 2016

The curlometer was introduced to estimate the electric current density from four‐point measurements in space; anticipating the realization of the four spacecraft Cluster mission which began full science operations in February 2001. The method uses Ampère's law to estimate current from the magnetic field measurements, suitable for the high‐conductivity plasma of the magnetosphere and surrounding regions. The accuracy of the method is limited by the spatial separation knowledge, accuracy of the magnetic field measurement, and the relative scale size of the current structures sampled but nevertheless has proven to be robust and reliable in many regions of the magnetosphere. The method has been applied successfully and has been a key element, in studies of the magnetopause currents; the magnetotail current sheet; and the ring current, as well as allowing other current structures such as flux tubes and field aligned currents to be determined. The method is also applicable to situations where less than four spacecraft are closely grouped or where special assumptions (particularly stationarity) can be made. In view of the new four‐point observations of the MMS mission taking place now, which cover a dramatically different spatial regime, we comment on the performance, adaptability, and lessons learnt from the curlometer technique. We emphasize the adaptability of the method, in particular, to the new sampling regime offered by the MMS mission; thereby offering a tool to address open questions on small‐scale current structures.
Photoelectrons and solar ionizing radiation at Mars: Predictions versus MAVEN observations
Authors: Peterson W. K. , Thiemann E. M. B , Eparvier Francis G. , Andersson Laila , Fowler C. M. , Larson Davin , Mitchell Dave , Mazelle Christian , Fontenla Juan , Evans J. Scott , Xu Shaosui , Liemohn Mike , Bougher Stephen , Sakai Shotaro , Cravens T. E. , Elrod M. K. , Benna M. , Mahaffy P. , Jakosky Bruce
Published: August 2016

Understanding the evolution of the Martian atmosphere requires knowledge of processes transforming solar irradiance into thermal energy well enough to model them accurately. Here we compare Martian photoelectron energy spectra measured at periapsis by Mars Atmosphere and Volatile Evolution MissioN (MAVEN) with calculations made using three photoelectron production codes and three solar irradiance models as well as modeled and measured CO2 densities. We restricted our comparisons to regions where the contribution from solar wind electrons and ions were negligible. The two intervals examined on 19 October 2014 have different observed incident solar irradiance spectra. In spite of the differences in photoionization cross sections and irradiance spectra used, we find the agreement between models to be within the combined uncertainties associated with the observations from the MAVEN neutral density, electron flux, and solar irradiance instruments.
Climatic impacts of the Middle Route of the South‐to‐North Water Transfer Project over the Haihe River basin in North China simulated by a regional climate model
Authors: Zou Jing , Zhan Chesheng , Xie Zhenghui , Qin Peihua , Jiang Shanshan
Published: August 2016

The Middle Route of the South‐to‐North Water Transfer Project (MSWTP) was constructed to ease the water crisis over the North China Plain. In this study, we incorporated a water transfer scheme into the regional climate model RegCM4 and investigated the climatic impacts of the MSWTP over the Haihe River Basin in North China. Four 10 year simulation tests were conducted from 2001 to 2010 where different volumes of water were transferred. The results demonstrated that before the MSWTP was conducted the original groundwater exploitation and consumption over the Haihe River Basin led to wetting and cooling at the land surface with rapidly falling groundwater depth. The extra water input from the MSWTP slightly enhanced the wetting and cooling effects over the basin, as well as reduced the falling rate in the groundwater depth along the conveyance line. However, the weak climatic effects of the MSWTP were limited at a local scale and had no obvious interannual trends, because the transfer volume of the MSWTP was far lower than the total demand which has been conventionally satisfied through local water exploitation. In terms of seasonal variations, the greatest changes due to the MSWTP occurred in the summer for precipitation and soil moisture and in the spring for energy‐related variables (heat fluxes and 2 m air temperature).
Measuring cloud thermodynamic phase with shortwave infrared imaging spectroscopy
Authors: Thompson David R. , McCubbin Ian , Gao Bo Cai , Green Robert O. , Matthews Alyssa A. , Mei Fan , Meyer Kerry G. , Platnick Steven , Schmid Beat , Tomlinson Jason , Wilcox Eric
Published: August 2016

Shortwave Infrared imaging spectroscopy enables accurate remote mapping of cloud thermodynamic phase at high spatial resolution. We describe a measurement strategy to exploit signatures of liquid and ice absorption in cloud top apparent reflectance spectra from 1.4 to 1.8 μm. This signal is generally insensitive to confounding factors such as solar angles, view angles, and surface albedo. We first evaluate the approach in simulation and then apply it to airborne data acquired in the Calwater‐2/ACAPEX campaign of Winter 2015. Here NASA's “Classic” Airborne Visible Infrared Imaging Spectrometer (AVIRIS‐C) remotely observed diverse cloud formations while the U.S. Department of Energy ARM Aerial Facility G‐1 aircraft measured cloud integral and microphysical properties in situ. The coincident measurements demonstrate good separation of the thermodynamic phases for relatively homogeneous clouds.
Engineering the Mechanics of Heterogeneous Soft Crystals
Authors: Cho Hansohl , Weaver James C. , Pöselt Elmar , in't Veld Pieter J. , Boyce Mary C. , Rutledge Gregory C.
Published: August 2016

This work demonstrates how the geometric and topological characteristics of substructures within heterogeneous materials can be employed to tailor the mechanical responses of soft crystals under large strains. The large deformation mechanical behaviors of elastomeric composites possessing long‐range crystalline order are examined using both experiments on 3D‐printed prototype materials and precisely matched numerical simulations. The deformation mechanisms at small and large strains are elucidated for six sets of morphologies: dispersed particles on each of the simple cubic, body‐centered cubic or face‐centered cubic lattices, and their bi‐continuous counterparts. Comparison of results for the six types of morphologies reveals that the topological connectivity of dissimilar domains is of critical importance for tailoring the macroscopic mechanical properties and the mechanical anisotropy.
Coating of Vertically Aligned Carbon Nanotubes by a Novel Manganese Oxide Atomic Layer Deposition Process for Binder‐Free Hybrid Capacitors
Authors: Silva Ricardo M. , Clavel Guylhaine , Fan Yafei , Amsalem Patrick , Koch Norbert , Silva Rui F. , Pinna Nicola
Published: August 2016

A novel atomic layer deposition process of manganese oxide from methylcyclopentadienyl manganese tricarbonyl and ozone has been developed. It is used to coat vertically aligned carbon nanotubes (VACNTs) grown on a conductive Inconel substrate in order to produce a 3D array of metal oxide‐carbon nanotube electrode. Electron microscopy studies show that a conformal polycrystalline film can be deposited on the VACNTs arrays. X‐ray diffraction, small area electron diffraction, and X‐ray photoelectron spectroscopy analysis determine the formation of hausmannite (Mn3O4). The electrochemical properties of the as‐prepared VACNTs/Mn3O4 nanocomposite electrodes are studied using cyclic voltammetry, galvanostatic charge and discharge cycling in 1 m Na2SO4 aqueous electrolyte. Capacitances as high as 78.62 mF cm−2 at 5 mV s−1 are demonstrated which is one order of magnitude higher than that of pristine VACNTs. In addition, the as‐prepared VACNTs/Mn3O4 nanocomposite electrode showed a good reversibility and cycling stability.
Stacked‐Disk Nanotower Arrays for Use as Omniphobic Surface‐Enhanced Raman Scattering Substrates
Authors: Jeon Tae Yoon , Kim Ju Hyeon , Park Sung‐Gyu , Kwon Jung‐Dae , Kim Dong‐Ho , Kim Shin‐Hyun
Published: August 2016

Herein, a simple interference lithographic technique to design omniphobic surface‐enhanced Raman scattering active surfaces composed of stacked‐disk nanotower arrays is reported. To create the nanotower arrays in a highly reproducible fashion, the authors use a single laser exposure onto the photoresist‐on‐dielectric mirror using a phase mask. The interference by the phase shift produces a nanotower array with a submicrometer periodicity, whereas the standing wave effect by reflection from the mirror defines the stacked‐disk structure at each nanotower at sub‐100 nm periodicity. The stacked‐disk nanotowers with silver outer‐coating provide a strong electric field localization at the vertically integrated nanogaps on the side wall. At the same time, the series of reentrant geometry on the side walls can efficiently pin the liquid–air interface for a variety of liquids, including water and toluene, thereby providing omniphobic surface property. The molecules dissolved in either water or toluene at low concentration can be enriched in the drop on the surface in a course of evaporation, which are finally deposited onto a tiny spot. Raman spectra of the molecules are further amplified by the strong electric field at the nanogaps on the side walls of the nanotowers. Therefore, the surfaces provide high sensitivity of Raman analysis for both polar and nonpolar molecules.
Independent Tailoring of Super‐Radiant and Sub‐Radiant Modes in High‐Q Plasmonic Fano Resonant Metasurfaces
Authors: Dayal Govind , Chin Xin Yu , Soci Cesare , Singh Ranjan
Published: August 2016

Fano resonances in plasmonic metasurfaces arise from the interference between a super‐radiant and a sub‐radiant plasmon mode. The interference of the plasmon modes, which gives rise to the Fano resonance phenomenon in a plasmonic metasurface, also restricts the independent control of the individual resonance modes. Independent tailoring of super‐radiant and sub‐radiant plasmon modes at nanoscale is one of the challenges to be addressed for the realization of targeted functionalities and fundamental understanding of plasmon mode coupling. Here, it is experimentally and numerically shown that the spectral position and line‐width of both the super‐radiant and sub‐radiant plasmonic modes of a Fano resonance can be independently controlled through the variation of metal film thickness at the skin depth scale and polarization of the incident light. The metasurface consists of a conductively coupled annular and rectangular aperture array that supports multiple high‐Q Fano resonances at near‐infrared frequencies. Fano resonances are excited via interference between the azimuthal plasmon mode of the annular aperture and the dipolar plasmon mode of the rectangular aperture. The multiple Fano resonances excited in the proposed design show remarkable sensitivity to skin‐depth scale film thicknesses, enabling independent control of spectral position and line‐shape of super‐radiant and sub‐radiant modes in high‐Q plasmonic Fano resonant metasurfaces.
Impact of emergency department care on outcomes of acute pain events in children with sickle cell disease
Authors: Brandow Amanda M. , Nimmer Mark , Simmons Timothy , Charles Casper T. , Cook Lawrence J. , Chumpitazi Corrie E. , Paul Scott J. , Panepinto Julie A. , Brousseau David C.
Published: August 2016

The impact of emergency department (ED) treatment on outcomes of sickle cell disease (SCD) acute pain hospitalizations is not well described. We investigated whether length of stay (LOS) and change in health‐related quality of life (HRQL) are affected by initial opioid dose and time to administration. We conducted secondary analyses of data from the randomized‐controlled Magnesium for children in Crisis (MAGiC) trial. The primary outcome was LOS. Secondary outcome was change in HRQL, assessed using PedsQL SCD Pain and Hurt and Pain Impact Domains measured in ED and at discharge. Independent variables were (1) time to first IV opioid, (2) total initial opioid dose (mg/kg/hr of morphine equivalents administered between ED and first study drug), and (3) Time to first oral opioid. Spearman correlations determined the associations with LOS. Using two‐sample t‐tests, we compared mean change in HRQL scores between IV opioid initiated within 60 and >60 min, opioid doses in the highest and lowest tertiles, and oral opioid initiated within 24 and >24 hr. Two hundred and four patients participated at 8 sites. Mean (SD) age was 13.6 (4.7) years. Earlier initiation of oral opioids was strongly correlated with shorter LOS (r = 0.61, P < 0.01). Higher initial opioid dose was weakly correlated with longer LOS (r = 0.34, P < 0.01). Higher initial opioid doses (6 vs −2.2; P = 0.01) and oral opioids initiated within 24 hr (5.7 vs −1.7, P = 0.04) were associated with larger mean change in HRQL at discharge. Prospective trials evaluating the impact of ED care on outcomes of pain hospitalizations could improve SCD pain treatment. Am. J. Hematol. 91:1175–1180, 2016. © 2016 Wiley Periodicals, Inc.
Rare HFE variants are the most frequent cause of hemochromatosis in non‐c282y homozygous patients with hemochromatosis
Authors: Hamdi‐Rozé Houda , Beaumont‐Epinette Marie‐Pascale , Ben Ali Zeineb , Le Lan Caroline , Loustaud‐Ratti Véronique , Causse Xavier , Loreal Olivier , Deugnier Yves , Brissot Pierre , Jouanolle Anne‐Marie , Bardou‐Jacquet Edouard
Published: August 2016

p.Cys282Tyr (C282Y) homozygosity explains most cases of HFE‐related hemochromatosis, but a significant number of patients presenting with typical type I hemochromatosis phenotype remain unexplained. We sought to describe the clinical relevance of rare HFE variants in non‐C282Y homozygotes. Patients referred for hemochromatosis to the National Reference Centre for Rare Iron Overload Diseases from 2004 to 2010 were studied. Sequencing was performed for coding region and intronic flanking sequences of HFE, HAMP, HFE2, TFR2, and SLC40A1. Nine private HFE variants were identified in 13 of 206 unrelated patients. Among those, five have not been previously described: p.Leu270Argfs*4, p.Ala271Valfs*25, p.Tyr52*, p.Lys166Asn, and p.Asp141Tyr. Our results show that rare HFE variants are identified more frequently than variants in the other genes associated with iron overload. Rare HFE variants are therefore the most frequent cause of hemochromatosis in non‐C282Y homozygote HFE patients. Am. J. Hematol. 91:1202–1205, 2016. © 2016 Wiley Periodicals, Inc.
Higher plasma orexin a levels in children with Prader–Willi syndrome compared with healthy unrelated sibling controls
Authors: Manzardo Ann M. , Johnson Lisa , Miller Jennifer L. , Driscoll Daniel J. , Butler Merlin G.
Published: August 2016

Prader–Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder associated with maladaptive social behavior, hyperphagia and morbid obesity. Orexin A is a hypothalamic neuropeptide important as a homeostatic regulator of feeding behavior and in energy metabolism through actions in the lateral hypothalamus. Dysregulation of orexin signaling may contribute to behavioral problems and hyperphagia seen in PWS and we sought to assess orexin A levels in PWS relative to controls children. Morning fasting plasma orexin A levels were analyzed in 23 children (aged 5–11 years) with genetically confirmed PWS and 18 age and gender matched healthy unrelated siblings without PWS. Multiplex immune assays utilized the Milliplex Human Neuropeptide Magnetic panel and the Luminex platform. Natural log‐transformed orexin A data were analyzed using general linear model adjusting for diagnosis, gender, age, total body fat, and body mass index (BMI). Plasma orexin A levels were significantly higher (P < 0.006) in children with PWS (average ±SD = 1,028 pg/ml ± 358) compared with unrelated siblings (average ±SD = 609 pg/ml ± 351; P < 0.001). Orexin A levels correlated with age in females and were significantly elevated in PWS even after these effects were controlled. These findings support the hypothesis that dysregulation of orexin signaling may contribute to behavioral problems and hyperphagia in PWS. Further studies are warranted to better understand the complex relationship between orexin A levels and the problematic behaviors consistently found in individuals with PWS. © 2016 Wiley Periodicals, Inc.
Associations of rare nicotinic cholinergic receptor gene variants to nicotine and alcohol dependence
Authors: Zuo Lingjun , Tan Yunlong , Li Chiang‐Shan R. , Wang Zhiren , Wang Kesheng , Zhang Xiangyang , Lin Xiandong , Chen Xiangning , Zhong Chunlong , Wang Xiaoping , Wang Jijun , Lu Lu , Luo Xingguang
Published: August 2016

Nicotine's rewarding effects are mediated through distinct subunits of nAChRs, encoded by different nicotinic cholinergic receptor (CHRN) genes and expressed in discrete regions in the brain. In the present study, we aimed to test the associations between rare variants at CHRN genes and nicotine dependence (ND), and alcohol dependence (AD). A total of 26,498 subjects with nine different neuropsychiatric disorders in 15 independent cohorts, which were genotyped on Illumina, Affymetrix, or PERLEGEN microarray platforms, were analyzed. Associations between rare variants (minor allele frequency (MAF) <0.05) at CHRN genes and nicotine dependence, and alcohol dependence were tested. The mRNA expression of all Chrn genes in whole mouse brain and 10 specific brain areas was investigated. All CHRN genes except the muscle‐type CHRNB1, including eight genomic regions containing 11 neuronal CHRN genes and three genomic regions containing four muscle‐type CHRN genes, were significantly associated with ND, and/or AD. All of these genes were expressed in the mouse brain. We conclude that CHRNs are associated with ND (mainly) and AD, supporting the hypothesis that the full catalog of ND/AD risk genes may contain most neuronal nAChRs‐encoding genes. © 2016 Wiley Periodicals, Inc.
Carbokatalyse in Flüssigphasenreaktionen
Authors: Su Dang Sheng , Wen Guodong , Wu Shuchang , Peng Feng , Schlögl Robert
Published: August 2016

Die metallfreie Katalyse ist in Bezug auf nachhaltige Chemie auf ein breites Interesse gestoßen. Kohlenstoffkatalyse ist eine “grüne” Alternative für katalytische Prozesse in der Gas‐ und Flüssigphase. Insbesondere für Dehydrierungen in der Gasphase wurde dies anhand von zahlreichen Beispielen dokumentiert, wobei Kohlenstoff ein vielversprechender Ersatz für Metalloxidsysteme sein kann. Die Kohlenstoffkatalyse in der Flüssigphase, speziell in der organischen Synthese, ist eine aufstrebende Forschungsrichtung, die sich in den letzten Jahren sehr schnell entwickelt hat. Hier wird der aktuelle Entwicklungsstand von Kohlenstoffkatalysatoren für Flüssigphasenreaktionen kritisch analysiert, wobei ein Fokus auf die Reaktionsmechanismen sowie auf Vorteile und Einschränkungen von metallfreien Kohlenstoffkatalysatoren gelegt ist.
Microstructure modulation of α‐Al2O3 hollow fiber membranes with four‐channel geometric configuration
Authors: Cai Chao , Zhang Yuting , Zhang Chun , Gu Xuehong
Published: August 2016

α‐Al2O3 four‐channel hollow fiber (4CHF) membrane owns high permeability as well as great mechanical strength. In this work, three typical microstructures of 4CHF membranes with sponge‐like layer located in centric (S1), inner (S2) and outer (S3) regions were demonstrated by changing polyethersulfone content of spinning suspension, ethanol contents of internal and external coagulants, respectively. The 4CHF‐S1 membrane could be prepared by using water as both internal and external coagulants. The central sponge‐like region expanded towards both surface sides with the polyethersulfone content. The 4CHF‐S2 membrane was obtained by using ethanol as internal coagulant while water as external coagulant. And the 4CHF‐S3 membrane was achieved by using ethanol as internal coagulant while water as external coagulant. The typical 4CHF‐S1, 4CHF‐S2 and 4CHF‐S3 membranes exhibited pure water fluxes of 3.38, 3.34 and 3.74 m3 · m−2 · h−1 and fracture loads of 20.86, 20.08 and 18.12 N, respectively. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Simplified modeling of the electrospinning process from the stable jet region to the unstable region for predicting the final nanofiber diameter
Authors: Ismail Nagham , Maksoud Fouad Junior , Ghaddar Nesreen , Ghali Kamel , Tehrani‐Bagha Ali
Published: August 2016

Electrospinning allows the production of ultrafine nanofibers through the stretching of a charged polymer jet with an external electrostatic field. In this study, we derived a simplified and accurate model relating the processing parameters, including the solution volumetric flow rate (Q), the applied electric field (E), and the polymer concentration, to the final fiber diameter. The model takes into consideration the jet behavior starting at the stable region and moving to the bending instability region. We validated the model experimentally by performing the electrospinning process with a polyacrylonitrile/N,N‐dimethylformamide solution with different ranges of concentrations (8–11 wt %), Qs (900–1320 μL/h), and Es (88,889–113,889 V/m). The final fiber diameter was measured with scanning electron microscopy. The model predicted the fiber diameter with a relative error of less than 10%. Moreover, a 30% increase in Q resulted in a 15% increase in the fiber diameter, whereas a 30% increase in E resulted in a 14% decrease in the fiber diameter. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44112.
Fast‐swelling superabsorbent polymers with polymerizable macromolecular surfactant as crosslinker
Authors: Chen Haiming , Huang He
Published: August 2016

Fast‐swelling superabsorbent polymers (SAPs) have been prepared by micellar cross‐linking copolymerization of acrylic acid and acrylamide using polymerizable macromolecular surfactants (PMSs) as multifunctional crosslinkers, with a foaming technique. Sodium bicarbonate (NaHCO3)/acetone and Pluronic F127 were used as foam (or porosity) generators and stabilizer, respectively. It has been found that the PMSs with different polyethylene glycol (PEG) chain length have little effect on the swelling rate of the SAPs, while the foam generators are crucial. In addition, the monomer concentration and the concentration of the PMS are important to the fast swelling rate of the SAPs. For a balance of a relatively fast‐swelling rate, high water absorbency under load and low cost in drying, a monomer concentration of above 50%, 0.08% PMS, and 5% NaHCO3 are preferable. The water absorbency of SAP prepared under optimal conditions could reach half of equilibrium water absorbency in 30 seconds and the saline water absorbency under load could reach 18.4 g/g. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44173.
Crystallinity, ion conductivity, and thermal and mechanical properties of poly(ethylene oxide)–illite nanocomposites with exfoliated illite as a filler
Authors: Zhen Ran , Chi Qianwen , Wang Xingyuan , Yang Kuo , Jiang YinShan , Li FangFei , Xue Bing
Published: August 2016

Illite particles were exfoliated by the intercalation and subsequent deintercalation of dimethyl sulfoxide (DMSO) in the interlayer of illite, and the exfoliated illite particles were used to prepare a novel poly(ethylene oxide) (PEO)–illite nanocomposite. The resulting exfoliated illite and PEO–illite nanocomposites were characterized by X‐ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry, ion conductivity testing, thermogravimetry analysis, and mechanical testing. The XRD results showed that the acid treatment of illite to exchange K+ in the interlayer of illite with H+ was a necessary condition for the DMSO intercalation. SEM micrographs confirmed the exfoliation of the illite particles in the process of DMSO deintercalation from the interlayer of the illite–DMSO intercalation complex. A good dispersion of exfoliated illite in the PEO matrix was also confirmed. A gradual decrease in the PEO crystallinity in the PEO–illite nanocomposites was observed with increasing exfoliated illite concentration. The ion conductivity of the nanocomposites gradually increased with the filler content and reached 3.21 × 10−5 S/cm at an illite concentration of 20 wt %. The formation of an amorphous region around the exfoliated illite was beneficial for Li+‐ion conduction. The ion conductivity significantly increased when the amorphous regions were connected to each other to form a conducting path for Li+ ions with a high filler concentration of greater than 10 wt %. Meanwhile, the thermooxidative stability and mechanical properties of the PEO–illite nanocomposites were also enhanced when exfoliated illite was introduced into the polymer matrix. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44226.
Dental Defects as a Potential Indicator of Chronic Malnutrition in a Population of Fallow Deer (Dama dama) from Northwestern Germany
Authors: Kierdorf Horst , Filevych Olexander , Lutz Walburga , Kierdorf Uwe
Published: August 2016

We studied enamel defects in mandibular cheek teeth of fallow deer from an enclosed population that had grown far beyond the carrying capacity of its habitat. Macroscopic inspection revealed a high frequency of pathological enamel alterations in the permanent premolars and the third molar, which form late during dental development, while earlier forming teeth (deciduous premolars and first molar) were generally not affected. Macroscopic enamel alterations comprised opacity and posteruptive discoloration, loss of occlusal enamel ridges, and presence of enamel surface lesions. Backscattered electron imaging in the SEM revealed a marked hypomineralization and related increased porosity of the outer compared to the central and inner enamel portions in the affected teeth. In contrast, the enamel of the unaffected first molars showed a homogeneous high degree of mineralization. Microindentation hardness testing demonstrated a significantly reduced and highly variable hardness of the outer enamel of the affected teeth. The recorded enamel alterations are indicative of a disturbance of enamel maturation. Based on findings of experimental studies by other authors that explored the effects of dietary deficiencies on the mineralization of dental hard tissues in different mammal species, we suggest a dietary calcium deficiency as the cause of the observed pathological enamel changes in the fallow deer. The supposed calcium deficiency only affected teeth whose crown mineralization takes place after weaning, while the deciduous premolars and the first molar, whose crown formation occurs prenatally or during the early postnatal period of intense milk feeding, were unaffected. Anat Rec, 299:1409–1423, 2016. © 2016 Wiley Periodicals, Inc.
Suppression of Toll‐Like Receptor 4 Dimerization by 1‐[5‐Methoxy‐2‐(2‐nitrovinyl)phenyl]pyrrolidine
Authors: Ahn Sang‐Il , Kim Ji‐Soo , Gu Gyo‐Jeong , Shin Hyeon‐Myeong , Kim Ah‐Yeon , Shim Hyun‐Jin , Kim Yeon Joo , Koh Kwang Oh , Mang Joo Yang , Kim Dae Young , Youn Hyung‐Sun
Published: August 2016

Toll‐like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS) and triggers the activation of myeloid differention factor 88 (MyD88) and the Toll/interleukin‐1 receptor domain‐containing adapter, inducing interferon‐β (TRIF)‐dependent major downstream signaling pathways. To evaluate the therapeutic potential of 1‐[5‐methoxy‐2‐(2‐nitrovinyl)phenyl]pyrrolidine (MNP), previously synthesized in our laboratory, its effect on signal transduction via the TLR signaling pathways was examined. Here, we investigated whether MNP modulates the TLR4 signaling pathways and which anti‐inflammatory target in TLR4 signaling is regulated by MNP. MNP inhibited the activation of nuclear factor‐κB (NF‐κB) induced by LPS (TLR4 agonist), and it also inhibited the expression of cyclooxygenase‐2 and inducible nitric oxide synthase. MNP inhibited LPS‐induced NF‐κB activation by targeting TLR4 dimerization in addition to IKKβ. These results suggest that MNP can modulate the TLR4 signaling pathway at the receptor level to decrease inflammatory gene expression.
Caco‐2 cells – expression, regulation and function of drug transporters compared with human jejunal tissue
Authors: Brück S. , Strohmeier J. , Busch D. , Drozdzik M. , Oswald S.
Published: August 2016

Background

Induction or inhibition of drug transporting proteins by concomitantly administered drugs can cause serious drug–drug interactions (DDIs). However, in vitro assays currently available are mostly for studying the inhibitory potential of drugs on intestinal transporter proteins, rather than induction. Therefore, this study investigated the suitability of the frequently used intestinal Caco‐2 cell line to predict transporter‐mediated DDIs as caused by induction via activation of nuclear receptors.

Methods

TaqMan® low density arrays and LC–MS/MS based targeted proteomics were used to evaluate transporter expression in Caco‐2 cells in comparison with jejunal tissue, in culture–time dependence studies and after incubation with different known inducers of drug metabolism and transport. Additionally, studies on ABCB1 function were performed using Transwell® assays with [3H]‐digoxin and [3H]‐talinolol as substrates after incubation with the prototypical inducers rifampicin, St John's wort, carbamazepine and efavirenz.

Results

The gene and protein expression pattern of drug transporters in Caco‐2 cells and jejunal tissue differed considerably. For some transporters culture‐time dependent differences in mRNA expression and/or protein abundance could be determined. Finally, none of the studied prototypical inducers showed an effect either on mRNA expression and protein abundance or on the function of ABCB1.

Conclusion

Differences in transporter expression in Caco‐2 cells compared with jejunal tissue, as well as expression dependence on culture time must be considered in in vitro studies to avoid under‐ or overestimation of certain transporters. The Caco‐2 cell model is not suitable for the evaluation of DDIs caused by transporter induction. Copyright © 2016 John Wiley & Sons, Ltd.
Characterization of loxoprofen transport in Caco‐2 cells: the involvement of a proton‐dependent transport system in the intestinal transport of loxoprofen
Authors: Narumi Katsuya , Kobayashi Masaki , Kondo Ayuko , Furugen Ayako , Yamada Takehiro , Takahashi Natsuko , Iseki Ken
Published: August 2016

Loxoprofen, a propionate non‐steroidal anti‐inflammatory drug (NSAID), is used widely in East Asian countries. However, little is known about the transport mechanisms contributing to its intestinal absorption. The objectives of this study were to characterize the intestinal transport of loxoprofen using the human intestinal Caco‐2 cell model. The transport of loxoprofen was investigated in cellular uptake studies. The uptake of loxoprofen into Caco‐2 cells was pH‐ and concentration‐dependent, and was described by a Michaelis–Menten equation with passive diffusion (Km: 4.8 mm, Vmax: 142 nmol/mg protein/30 s, and Kd: 2.2 μl/mg protein/30 s). Moreover, the uptake of loxoprofen was inhibited by a typical monocarboxylate transporter (MCT) inhibitor as well as by various monocarboxylates. The uptake of [14C] l‐lactic acid, a typical MCT substrate, in Caco‐2 cells was saturable with relatively high affinity for MCT. Because loxoprofen inhibited the uptake of [14C] l‐lactic acid in a noncompetitive manner, it was unlikely that loxoprofen uptake was mediated by high‐affinity MCT(s). Our results suggest that transport of loxoprofen in Caco‐2 cells is, at least in part, mediated by a proton‐dependent transport system. Copyright © 2016 John Wiley & Sons, Ltd.
Outcome after associating liver partition and portal vein ligation for staged hepatectomy and conventional two-stage hepatectomy for colorectal liver metastases
Authors: Adam R , Imai K , Castro Benitez C , Allard M-A , Vibert E , Sa Cunha A , Cherqui D , Baba H , Castaing D
Published: August 2016

Background

Although associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been increasingly adopted by many centres, the oncological outcome for colorectal liver metastases compared with that after two-stage hepatectomy is still unknown.

Methods

Between January 2010 and June 2014, all consecutive patients who underwent either ALPPS or two-stage hepatectomy for colorectal liver metastases in a single institution were included in the study. Morbidity, mortality, disease recurrence and survival were compared.

Results

The two groups were comparable in terms of clinicopathological characteristics. ALPPS was completed in all 17 patients, whereas the second-stage hepatectomy could not be completed in 15 of 41 patients. Ninety-day mortality rates for ALPPS and two-stage resection were 0 per cent (0 of 17) versus 5 per cent (2 of 41) (P = 0·891). Major complication rates (Clavien grade at least III) were 41 per cent (7 of 17) and 39 per cent (16 of 41) respectively (P = 0·999). Overall survival was significantly lower after ALPPS than after two-stage hepatectomy: 2-year survival 42 versus 77 per cent respectively (P = 0·006). Recurrent disease was more often seen in the liver in the ALPPS group. Salvage surgery was less often performed after ALPPS (2 of 8 patients) than after two-stage hepatectomy (10 of 17).

Conclusion

Although major complication and 90-day mortality rates of ALPPS were similar to those of two-stage hepatectomy, overall survival was significantly lower following ALPPS.
An LC–MS/MS method for simultaneous determination of 1,5‐dicaffeoylquinic acid and 1‐O‐acetylbritannilactone in rat plasma and its application to a pharmacokinetic study
Authors: Wang Zhe , Wang Shixi , Qin Baoli
Published: August 2016

A selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for the simultaneous quantitative determination of 1,5‐dicaffeoylquinic acid (1,5‐DCQA) and 1‐O‐acetylbritannilactone (1‐O‐ABL) in rat plasma. Chromatographic separation was performed on a Zorbax Eclipse XDB‐C18 column using isocratic mobile phase consisting of methanol–water–formic acid (70:30:0.1, v/v/v) at a flow rate of 0.25 mL/min. The detection was achieved using a triple‐quadrupole tandem MS in selected reaction monitoring mode. The calibration curves of all analytes in plasma showed good linearity over the concentration ranges of 0.850–213 ng/mL for 1,5‐DCQA, and 0.520–130 ng/mL for 1‐O‐ABL, respectively. The extraction recoveries were ≥78.5%, and the matrix effect ranged from 91.4 to 102.7% in all the plasma samples. The method was successfully applied for the pharmacokinetic study of the two active components in the collected plasma following oral administration of Inula britannica extract in rats.
An LC–MS/MS method for simultaneous determination of hosenkoside A and hosenkoside K from Semen Impatientis in rat plasma and its application to a pharmacokinetic study
Authors: Yu Xiaodong , Bi Binna , Dong Ning , Zhao Huanli , Ji Lixin , Lu Minghua
Published: August 2016

A rapid and sensitive liquid chromatography tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous determination of two baccharane glycosides (hosenkoside A and hosenkoside K) of total saponins of Semen Impatientis in rat plasma using mogroside V as the internal standard (IS). The analytes were separated using a C18 RP Agilent XDB column (1.8 μm, 50 × 2.1 mm i.d.) and detection of the compounds was done using a TSQ Quantum triple quadrupole mass spectrometer coupled with a negative electrospray ionization source under selection reaction monitoring mode. According to the US Food and Drug Administration guidelines, the established method was fully validated and the results were proved within acceptable limits. The lower limits of quantification of both analytes were 5 ng/mL. The validated method was successfully applied to a pharmacokinetic study of orally administered the total saponins of Semen Impatientis in rats.
Functional neuroimaging of visual creativity: a systematic review and meta‐analysis
Authors: Pidgeon Laura M. , Grealy Madeleine , Duffy Alex H. B. , Hay Laura , McTeague Chris , Vuletic Tijana , Coyle Damien , Gilbert Sam J.
Published: August 2016

Introduction

The generation of creative visual imagery contributes to technological and scientific innovation and production of visual art. The underlying cognitive and neural processes are, however, poorly understood.

Methods

This review synthesizes functional neuroimaging studies of visual creativity. Seven functional magnetic resonance imaging (fMRI) and 19 electroencephalography (EEG) studies were included, comprising 27 experiments and around 800 participants.

Results

Activation likelihood estimation meta‐analysis of the fMRI studies comparing visual creativity to non‐rest control tasks yielded significant clusters in thalamus, left fusiform gyrus, and right middle and inferior frontal gyri. The EEG studies revealed a tendency for decreased alpha power during visual creativity compared to baseline, but comparisons of visual creativity to non‐rest control tasks revealed inconsistent findings.

Conclusions

The findings are consistent with suggested contributions to visual creativity of prefrontally mediated inhibition, evaluation, and working memory, as well as visual imagery processes. Findings are discussed in relation to prominent theories of the neural basis of creativity.