bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of C(sp2)Boronate Esters by Borylative Cyclization of Alkynes Using BCl3
Authors: Warner Andrew J. , Lawson James R. , Fasano Valerio , Ingleson Michael J.
Published: August 2015

BCl3 is an inexpensive electrophile which induces the borylative cyclization of a wide range of substituted alkynes to regioselectively form polycycles containing synthetically versatile C(sp2)boronate esters. It proceeds rapidly, with good yields and is compatible with a range of functional groups and substitution patterns. Intermolecular 1,2‐carboboration of alkynes is also achieved using BCl3 to generate trisubstituted vinyl boronate esters.
Finely Tuned Polymer Interlayers Enhance Solar Cell Efficiency
Authors: Liu Yao , Page Zachariah A. , Russell Thomas P. , Emrick Todd
Published: August 2015

Three conjugated polymer zwitterions (CPZs), containing thiophene‐, diketopyrrolopyrrole‐ (DPP), and naphthalene diimide (NDI) backbones, were synthesized with pendant zwitterions, specifically sulfobetaine groups. Diboronate‐ester‐functionalized bithiophene and benzothiadiazole monomers were copolymerized with zwitterion‐substituted dibromothiophene, DPP, and NDI monomers by A2+B2 Suzuki polymerization. The CPZs were incorporated into polymer solar cells (PSCs) as interlayers between the photoactive layer and Ag cathode. The thiophene‐based CPZs gave power conversion efficiencies (PCEs) of about 5 %, while the narrow‐energy‐gap DPP‐ and NDI‐based CPZs performed exceptionally well, giving PCEs of 9.49 % and 10.19 %, respectively. The interlayer thickness had only a minor impact on the device performance for the DPP‐ and NDI‐CPZs, a finding attributed to their electron‐transport properties. Ultraviolet photoelectron and reflectance spectroscopies, combined with external quantum efficiency measurements, provided structure–property relationships that lend insight into the function of CPZ interlayers in PSCs. NDI‐based CPZ interlayers provide some of the best performing organic solar cells reported to date, and prove useful in conjunction with high‐performing polymer‐active layers and stable, high‐work‐function, metal cathodes.
Palladium(II)‐Catalyzed Allylic CH Oxidation of Hindered Substrates Featuring Tunable Selectivity Over Extent of Oxidation
Authors: Xing Xiangyou , O'Connor Nicholas R. , Stoltz Brian M.
Published: August 2015

The use of Oxone and a palladium(II) catalyst enables the efficient allylic CH oxidation of sterically hindered α‐quaternary lactams which are unreactive under known conditions for similar transformations. This simple, safe, and effective system for CH activation allows for unusual tunable selectivity between a two‐electron oxidation to the allylic acetates and a four‐electron oxidation to the corresponding enals, with the dominant product depending on the presence or absence of water. The versatile synthetic utility of both the allylic acetate and enal products accessible through this methodology is also demonstrated.
Frontoparietal Bone in Extinct Palaeobatrachidae (Anura): Its Variation and Taxonomic Value
Authors: Roček Zbyněk , Boistel Renaud , Lenoir Nicolas , Mazurier Arnaud , Pierce Stephanie E. , Rage Jean‐Claude , Smirnov Sergei V. , Schwermann Achim H. , Valentin Xavier , Venczel Márton , Wuttke Michael , Zikmund Tomáš
Published: August 2015

Palaeobatrachidae are extinct frogs from Europe closely related to the Gondwanan Pipidae, which includes Xenopus. Their frontoparietal is a distinctive skeletal element which has served as a basis for establishing the genus Albionbatrachus. Because little was known about developmental and individual variation of the frontoparietal, and its usefulness in delimiting genera and species has sometimes been doubted, we investigate its structure in Palaeobatrachus and Albionbatrachus by means of X‐ray high resolution computer tomography (micro‐CT). To infer the scope of variation present in the fossil specimens, we also examined developmental and interspecific variation in extant Xenopus. In adults of extinct taxa, the internal structure of the frontoparietal bone consists of a superficial and a basal layer of compact bone, with a middle layer of cancellous bone between them, much as in early amphibians. In Albionbatrachus, the layer of cancellous bone, consisting of small and large cavities, was connected with the dorsal, sculptured surface of the bone by a system of narrow canals; in Palaeobatrachus, the layer of cancellous bone and the canals connecting this layer with the dorsal surface of the frontoparietal were reduced. The situation in Palaeobatrachus robustus from the lower Miocene of France is intermediate—while external features support assignment to Palaeobatrachus, the inner structure is similar to that in Albionbatrachus. It may be hypothesized that sculptured frontoparietals with a well‐developed layer of cancellous (i.e., vascularized) bone may indicate adaptation to a more terrestrial way of life, whereas a reduced cancellous layer might indicate a permanent water dweller. Anat Rec, 298:1848–1863, 2015. © 2015 Wiley Periodicals, Inc.
A rapid UPLC‐MS/MS method for the determination of oleanolic acid in rat plasma and liver tissue: application to plasma and liver pharmacokinetics
Authors: Li Tian‐xue , Chu Chao‐sen , Zhu Jia‐yu , Yang Tian‐yi , Zhang Jie , Hu Yu‐tao , Yang Xing‐hao
Published: August 2015

A reliable high‐throughput ultra‐high performance liquid chromatography–tandem mass spectrometry (UPLC‐MS/MS) method was developed and validated for oleanolic acid (OA) determination in rat plasma and liver tissue using glycyrrhetic acid as the internal standard (IS). Plasma and liver homogenate samples were prepared using solid‐phase extraction. Chromatographic separation was achieved on a C18 column using an isocratic mobile phase system. The detection was performed by multiple reaction monitoring mode via positive electrospray ionization interface. The calibration curves showed good linearity (R2 > 0.9997) within the tested concentration ranges. The lower limit of quantification for plasma and liver tissue was ≤0.75 ng/mL. The intra‐ and inter‐day precision and accuracy deviations were within ±15% in plasma and liver tissue. The mean extraction recoveries ranged from 80.8 to 87.0%. In addition, the carryover, matrix effect, stability and robustness involved in the method were also validated. The method was successfully applied to the plasma and hepatic pharmacokinetics of OA after oral administration to rats. Copyright © 2015 John Wiley & Sons, Ltd.
Discovery and Characterization of New Hydroxamate Siderophores, Baumannoferrin A and B, produced by Acinetobacter baumannii
Authors: Penwell William F. , DeGrace Nancy , Tentarelli Sharon , Gauthier Lise , Gilbert Catherine M. , Arivett Brock A. , Miller Alita A. , Durand‐Reville Thomas F. , Joubran Camil , Actis Luis A.
Published: August 2015

Acinetobacter baumannii AYE does not produce acinetobactin but grows under iron limitation. Accordingly, analyses of AYE iron‐restricted culture supernatants resulted in the isolation of two fractions, which contained only hydroxamates and showed siderophore activity. Structural analyses identified baumannoferrin A and baumannoferrin B, which differ only by a double bond. These siderophores are composed of citrate, 1,3‐diaminopropane, 2,4‐diaminobutyrate, decenoic acid, and α‐ketoglutarate. Analysis of the AYE genome showed the presence of a 12‐gene cluster coding for proteins similar to those involved in the production and utilization of the hydroxamate siderophores acinetoferrin and achromobactin. As A. baumannii AYE does not produce acinetobactin and harbors only one gene cluster encoding the production and utilization of a siderophore, this strain's growth under iron limitation depends on baumannoferrin, a novel hydroxamate that could play a role in its virulence.
Microreactors as a Tool for Acquiring Kinetic Data on Photochemical Reactions
Authors: Aillet Tristan , Loubière Karine , Dechy‐Cabaret Odile , Prat Laurent
Published: August 2015

For the first time, the application of microreactors as a tool for acquiring kinetic data on a photochemical reaction is demonstrated. For illustration, a T‐photochromic system is considered. By using modeling tools and carrying out specific experiments in a spiral‐shaped microreactor irradiated by an ultraviolet/light‐emitting diode (UV‐LED) array, the two kinetic parameters of the reaction, namely, quantum yield and rate of thermal back reaction, are determined. Once these parameters are known, the photochromic reaction is performed in two other microreactors in order to investigate a wider range of operating conditions. It is observed that a critical residence time exists beyond which the conversion into the open form decreases due to a decomposition reaction. The value of the critical residence depends on the microreactor type, which can be predicted by applying the model developed.
Synthesis and Atropisomerism of Cascaded Tetraphenylporphyrin–[60]Fullerene Hybrids
Authors: Schlundt Sebastian , Bauer Walter , Hirsch Andreas
Published: August 2015

Flexible, linked dendritic tetraphenylporphyrin (TPP)–fullerene hybrids were synthesized. They were designed to gain insight into and mimic the primary events in the natural photosynthetic reaction center. These multiporphyrin moieties are based on a light‐harvesting concept. Moreover, they incorporate multiple redox components aligned along a redox gradient. Newkome‐type dendrons were added to these TPP–fullerene hybrids. In principle they can mediate pH‐dependent water solubility, which, however, could not be observed in this case. A protecting‐group strategy using tert‐butyldiphenylsilyl groups allows convergent synthesis of the dendritic compounds. The dendritic multiporphyrins were synthesized separately and can be used as individual building blocks. Atropisomerism was observed in the dendritic compounds, and single atropisomers could be assigned to the corresponding peaks of a characteristic pattern in the NMR spectra. Deprotection of the Newkome‐type dendrons was shown to be feasible under mild conditions that leave the redox gradient intact.
Steam‐Assisted Synthesis of an Extra‐Stable Polyoxometalate‐Encapsulating Metal Azolate Framework: Applications in Reagent Purification and Proton Conduction
Authors: Zhou En‐Long , Qin Chao , Wang Xin‐Long , Shao Kui‐Zhan , Su Zhong‐Min
Published: August 2015

Different from the conventional synthesis approaches, such as hydrothermal or solvothermal synthesis, a porous metal azolate framework encapsulating Keggin‐type [SiW12O40]4− anions was prepared by an environmentally friendly, low‐cost, and highly efficient steam‐assisted conversion method for the first time. The nanosized polyoxometalates as a template were encapsulated by a zeotype 6448 cage constructed by 28 nuclear zinc atoms connected through 32 Trz ligands. The obtained composite exhibits excellent thermal and chemical stability; meanwhile, its special ability to selectively absorb water from alcohols makes it efficiently separate water from analytically pure ethanol, with the result that water content decreases from 0.23 to 0.05 wt %, which is superior to the standard of chromatographic grade ethanol (<0.1 wt %). Besides, alternating current (ac) impedance experiments also reveal that the hybrid is a kind of proton conductive material.
Palladium‐Catalyzed Zinc‐Amide‐Mediated CH Arylation of Fluoroarenes and Heteroarenes with Aryl Sulfides
Authors: Otsuka Shinya , Yorimitsu Hideki , Osuka Atsuhiro
Published: August 2015

CH arylation of polyfluoroarenes and heteroarenes with aryl sulfides proceeds smoothly with the aid of a palladium–N‐heterocyclic carbene catalyst. A bulky zinc amide, TMPZnCl⋅LiCl, plays a key role as an effective base to generate the corresponding arylzinc species in situ. This arylation protocol is practically much easier to perform than our previous method, which necessitates preparation of the arylzinc reagents in advance from the corresponding aryl halides. Aryl sulfides that are prepared through sulfur‐specific reactions, such as SNAr sulfanylation and extended Pummerer reactions, undergo this direct arylation, offering interesting transformations that are otherwise difficult to achieve with conventional halogen‐based organic synthesis.
Synthesis of Silaphenalenes by Ruthenium‐Catalyzed Annulation between 1‐Naphthylsilanes and Internal Alkynes through CH Bond Cleavage
Authors: Tokoro Yuichiro , Sugita Kengo , Fukuzawa Shin‐ichi
Published: August 2015

Ruthenium‐catalyzed annulation of 1‐naphthylsilanes with internal alkynes afforded silaphenalenes through cleavage of the CH bond at the 8‐position of the naphthalene. [RuH2(CO){P(p‐FC6H4)3}3] efficiently catalyzed the reaction. The use of 1‐naphthyldiphenylsilane as a substrate resulted in a better yield of the annulation product compared to the use of silanes with alkyl groups on the silicon atom. Internal alkynes with both aryl and alkyl groups were tolerated in this reaction.
Characteristics of Boreal Winter Total Ozone Distribution in the Northern Hemisphere and Their Relationship with Stratospheric Temperature During Recent 30 Years
Authors: Gang LI , Yan‐Ke TAN , Chong‐Yin LI , Shu‐Chi CHEN , Tao BAI , Dao‐Yong YANG , Ying ZHANG
Published: August 2015

The characteristics of spatiotemporal distribution of total ozone have a significant impact on the variabilities of climate and environment. As the increase of the high quality and quantity of total ozone datasets, it is necessary to provide a detailed investigation of spatiotemporal distribution characteristics of total ozone and its relationship with climate variability. Based on the ECMWF global monthly mean total ozone and stratopheric temperature data from 1979 to 2013, the spatiotemporal structure of dominant total ozone pattern in the Northern Hemisphere (north of 20°N) during boreal winter is studied using the rotated empirical orthogonal function (REOF) analysis and Morlet wavelet analysis. Besides, the relationship of the dominant total ozone pattern with the temperature anomalies in the upper (2 hPa), middle (30 hPa) and lower (100 hPa) stratosphere is further studied using composite analysis. The results show that the variability of total ozone in the Northern Hemisphere during boreal winter is characterized by five significant dominant patterns during the recent 30 years, which are located in the Arctic region (75°N–90°N, 0°–360°), the subtropics of Northern Hemisphere (20°N–40°N, 0°–360°), the Alaska region (60°N–75°N, 180°E–260°E), the North Atlantic region (45°N–60°N, 310°E–360°E) and the Siberia region (50°N–65°N, 80°E–130°E). The five dominant patterns show significant variabilities on the interannual and interdecadal time scales. The total ozone over these five regions changes from more than normal to less than normal since the late 1980. On the interannual time scale, total ozone over the five regions shows pronounced periodicity. In addition, their periodicities show significant difference. The relationship between the dominant total ozone patterns and the stratospheric temperature indicates that, when the total ozone is increased (reduced), the upper stratosphere will be cooled (warmed), while the middle and lower stratosphere will be warmed (cooled). Furthermore, the middle stratosphere is warmer (cooler) than the lower stratosphere.
The Contribution of Structure and Evolution of Potential Vorticity Tower to the Intensity Change of Hurricane Wilma (2005)
Authors: Shuang LIU , Wei ZHONG , Ji‐Chen LIU , Han‐Cheng LU
Published: August 2015

In this study, the characteristics and evolution of the Potential Vorticity Tower (PVT) at different stages and its contribution to rapid intensification (RI) are investigated with the high‐resolution simulation of Hurricane Wilma (2005). Results show that inner‐core structure and intensity change of PVT depends mainly on the subsidence of the upper‐level warm‐core, the mid‐level latent heating and the low‐level dynamic instability. In particular, the structure and instability evolution of the low‐level azimuthally averaged PV shows closely relation to the speed of intensity change in RI process. The transition between Monopole PVT (MPVT) and Hollow PVT (HPVT) during the RI period induced by upper‐level warming, latent heating and the vertical mixing associated with convection, leads to dynamic instability changed in TCs. Furthermore, Two theoretical structural parameters, thickness and hollowness, are redefined in the simulated hurricane case so that the structural effect of the PVT on the intensity change of hurricanes could be quantitatively analysed. The correlation analysis of the structural parameters and the intensity change of Wilma (2005) during the RI period shows that the coefficients of the structural parameters and the change rate of minimum sea surface central pressure exceed the 99% confidence level, which indicates the high dependency between the PVT structure and the intensity change of hurricanes.
Fine Lithospheric Structure Beneath the Middle‐Southern Segment of the Tan‐Lu Fault Zone
Authors: Bao‐Jin LIU , Shao‐Ying FENG , Ji‐Fa JI , Jin‐Hu SHI , Ya‐Li TAN , Yi‐Qing LI
Published: August 2015

The Tan‐Lu Fault Zone (TLFZ) is the largest active tectonic belt in East China, and it has a complicated history of formation and evolution. It is proved to have been playing an important dominant role in regional tectonics, magmatic activity, formation and distribution of mineral resources as well as current earthquake activities. To analyze the lithospheric structure of the TLFZ and blocks on both its sides, we applied deep seismic reflection exploration in the vicinity of Suqian City of Jiangsu Province in 2010, which is located at the middle‐southern segment of the TLFZ. The results show that the Moho and the bottom boundary of lithosphere are both west‐dipping, where the crustal thickness is about 31∼36 km and the lithosphere thickness is about 75∼86 km with an abrupt step around 10 km beneath the TLFZ. The TLFZ is characterized by a “flower‐like” structure consisting of many major faults on the seismic section. Inside them developed graben basin and compressive folds with tectonic traces of extension, compression and strike‐slip coexisting, which indicates that the formation and evolution of the TLFZ experienced multi‐period complicated tectonic movements. The TLFZ is a deep major fault system, cutting the near‐surface sediment layer downward to the Moho and the lithospheric mantle. The upwelling of high temperature and high pressure (HTHP) materials from the asthenosphere along the fault zone, magma under‐plating and thermal erosion lead to lithospheric extension and thinning, which probably change the lithospheric structure and material composition. This study can not only further our comprehension of the deep and shallow structures in the TLFZ, but also provide the data for analyzing the deep process and shallow structure in the eastern part of the North China Craton (NCC).
Calculation of Co‐Seismic Effects of the Nepal MS8.1 Earthquake on 25 April 2015
Authors: Bei ZHANG , Hui‐Hong CHENG , Yao‐Lin SHI
Published: August 2015

The co‐seismic displacement and stress fields of the Nepal Ms8.1 earthquake on 25 April 2015 were calculated using the finite element method. Curvature of the Earth was included in our model to get accurate results in the far field. We adopted the PREM earth model and two different slip models in the calculation. The Nepal Ms8.1 earthquake is a typical low‐angle thrust event, of which the co‐seismic deformation is dominated by horizontal components. The co‐seismic displacement is mainly in north‐south direction and concentrates near Kathmandu. East‐west and vertical components are relatively small. The USGS slip model gave a maximum displacement around 3.5 m, while that of the CEA slip model is up to 1.2 m. The range of influence is about 300 km within which co‐seismic displacement is over 0.1 m. Coulomb failure stress change caused by the earthquake is positive in the vicinity of Nepal and its maximum is about 0.1 MPa. The Ms8.1 earthquake could affect China's Tibet region, especially in areas of the Yarlung Zangbo Jiang and the Lhasa block, where Coulomb failure stress changes are positive and the magnitude is up to 10 kPa for N‐S trending normal faults, which implies possibilities of triggering new major earthquakes.
April‐25‐2015 Nepal Mw7.8 Seismogenic Process Analysis and Post‐Quake Trend Prediction
Authors: Pei LI , Si‐Qing QIN , Lei XUE , Guo‐Liang LI
Published: August 2015

Based on the brittle failure theory of multiple locked patches in a seismogenic fault system and interplate seismic zoning principle proposed by the authors of this paper, the Islamabad–Kathmandu seismic zone is defined. Through seismogenic period definition and main shock event recognition, the seismogenic process of major/great earthquakes in this seismic zone is analyzed and the future trend of earthquake occurrence is predicted. The results show that the Islamabad–Kathmandu seismic zone is an Mw8.3∼8.6 earthquake hazard zone, and has undergone at least three complete seismogenic periods; the Nepal Mw7.8 earthquake on April 25, 2015 was a representative major earthquake event in the current seismogenic period when the damage of the third locked patch was accumulated to the peak strength point; After the Mw7.3 earthquake in Nepal on May 12, 2015, this seismic zone is already in another critical state of the current seismogenic period, and an Mw8.0∼8.2 earthquake would occur in short‐middle term.
Hybrid Pseudospectral/Finite‐Difference Numerical Simulation and Stability Analysis of Pure P‐Wave Propagation in Vti Media
Authors: Qi‐Zhen DU , Cheng‐Feng GUO , Xu‐Fei GONG
Published: August 2015

The attractive feature of pure P‐wave equations for anisotropic media is that it is completely free from shear‐wave artifacts, and can alleviate the numerical instabilities caused by anisotropy. We present the first‐order pure P‐wave velocity‐stress equation for transversely isotropic media with a vertical symmetry axis. Like most other pure acoustic anisotropic wave equations, our equation involves complicated pseudo‐differential operators in space, which cannot be solved with the finite‐difference method alone. For computational efficiency, we adopt an efficient hybrid pseudospectral (PS)/finite‐difference (FD) scheme to solve the pure P‐wave equation. The stability of the hybrid PS/FD scheme on central and staggered grids is investigated by von Neumann's method. Numerical tests on 2D synthetic examples demonstrate that the proposed pure P‐wave equation provides stable and kinetically accurate simulation results for complex anisotropic media.
Exploring the Effects of Glycosylation and Etherification of the Side Chains of the Anticancer Drug Mitoxantrone
Authors: Shaul Pazit , Steinbuch Kfir B. , Blacher Eran , Stein Reuven , Fridman Micha
Published: August 2015

Herein we report the synthesis and biological evaluation of symmetric and asymmetric analogues of the DNA intercalating drug mitoxantrone (MTX) in which the side chains of the parent drug were modified through glycosylation or methyl etherification. Several analogues with glycosylated side chains exhibited higher DNA affinity than the parent MTX. The most potent in vitro cytotoxicity was observed for MTX analogue 8 (1,4‐dimethoxy‐5,8‐bis[2‐(2‐methoxyethylamino)ethylamino]anthracene‐9,10‐dione) with methoxy ether containing side chains. Treatment of melanoma‐bearing mice with MTX or analogue 8 decreased the intraperitoneal tumor burden relative to untreated mice; the effect of 8 was less pronounced than that of MTX. In vitro metabolism assays of MTX with rabbit liver S9 fraction gave rise to several metabolites; almost no metabolites were detected for MTX analogue 8. The results presented indicate that derivatization of the MTX side chain primary hydroxy groups may result in a significant improvement in DNA affinity and lower susceptibility to the formation of potentially toxic metabolites.
From sauropsids to mammals and back: New approaches to comparative cortical development
Authors: Montiel Juan F. , Vasistha Navneet A. , Garcia‐Moreno Fernando , Molnár Zoltán
Published: August 2015

Evolution of the mammalian neocortex (isocortex) has been a persisting problem in neurobiology. While recent studies have attempted to understand the evolutionary expansion of the human neocortex from rodents, similar approaches have been used to study the changes between reptiles, birds, and mammals. We review here findings from the past decades on the development, organization, and gene expression patterns in various extant species. This review aims to compare cortical cell numbers and neuronal cell types to the elaboration of progenitor populations and their proliferation in these species. Several progenitors, such as the ventricular radial glia, the subventricular intermediate progenitors, and the subventricular (outer) radial glia, have been identified but the contribution of each to cortical layers and cell types through specific lineages, their possible roles in determining brain size or cortical folding, are not yet understood. Across species, larger, more diverse progenitors relate to cortical size and cell diversity. The challenge is to relate the radial and tangential expansion of the neocortex to the changes in the proliferative compartments during mammalian evolution and with the changes in gene expression and lineages evident in various sectors of the developing brain. We also review the use of recent lineage tracing and transcriptomic approaches to revisit theories and to provide novel understanding of molecular processes involved in specification of cortical regions. J. Comp. Neurol. 524:630–645, 2016. © 2015 The Authors. The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.
When does pleasure start after the end of pain? The time course of relief
Authors: Andreatta Marta , Mühlberger Andreas , Pauli Paul
Published: August 2015

Painful events are suggested to elicit two opponent responses: a negatively valenced and a positively valenced process triggered by their onset and termination, respectively. Consequently, stimuli (conditioned stimulus, CS) associated with pain onset (unconditioned stimulus, US) provoke defensive responses like startle potentiation, while stimuli associated with pain termination elicit appetitive responses like startle attenuation. Here we summarize four studies elucidating the time course of the relief following the termination of a painful US. In these studies, the timing of a relief‐associated stimulus (reliefCS) presented after a painful US was varied from immediately (Study1), 3 seconds (Study4), or 6 seconds (Study2 and 3) after the US. Responses to these relief CSs were compared also with responses to a stimulus presented before the US (fearCS), and a third stimulus (safetyCS) that was never associated with the US. The synopsis of these studies reveals that the timing of the reliefCS is crucial to turn a defensive response into an appetitive response. Namely, the reliefCS immediately following the US‐induced startle potentiation and negative valence (Study1); 3 seconds later, the startle response was slightly less potentiated and the ratings a little less negative (Study4); finally, the reliefCS presented 6 seconds after the US caused startle attenuation (Study2 and 3) and positively valenced ratings (Study3). In sum, the observed time course of relief closely follows the predictions of opponent process theory. This means that relief may be a reinforcer that elicits conditioned appetitive behavior, but its reinforcing properties strongly depend on its temporal relation to the aversive event. J. Comp. Neurol. 524:1653–1667, 2016. © 2015 Wiley Periodicals, Inc.
Does increasing applied load lead to contact changes indicative of knee osteoarthritis? A subject‐specific FEA study
Authors: Boyd Jennifer L. , Zavatsky Amy B. , Gill Harinderjit S.
Published: August 2015

This study investigated whether increased loading (representing obesity) in the extended knee and flexed knee led to increased stresses in areas of typical medial and lateral osteoarthritis cartilage lesions, respectively. We created two paired sets of subject‐specific finite element models; both sets included models of extended knees and of flexed knees. The first set represented normal loading; the second set represented increased loading. All other variables were held constant. The von Mises stresses and contact areas calculated on the tibial cartilage surfaces of the paired models were then compared.

In the extended knee models, applying a larger load led to increased stress in the anterior and central regions of the medial tibial cartilage. These are the typical locations of medial osteoarthritis cartilage lesions. Therefore, the results support that increased loading in the extended knee may result in medial osteoarthritis.

In the flexed knee models, applying a larger load increased stress in the anterior and central regions of the lateral tibial cartilage. Lateral osteoarthritis cartilage lesions typically occur centrally and posteriorly. Therefore, these results do not support our hypothesis. Shear stress was increased in areas of typical lateral lesions, however, and should be investigated in future studies. Copyright © 2015 John Wiley & Sons, Ltd.
Reduction of Charge and Discharge Polarization by Cobalt Nanoparticles‐Embedded Carbon Nanofibers for Li–O2 Batteries
Authors: Kim Yun‐Jung , Lee Hongkyung , Lee Dong Jin , Park Jung‐Ki , Kim Hee‐Tak
Published: August 2015

Invited for this month’s cover is the group of Jung‐Ki Park and Hee‐Tak Kim at Korea Advanced Institute of Science and Technology. The image shows cobalt nanoparticles embedded in carbon nanofibers for use in lithium oxygen (Li–O2) battery: the fibers attract oxygen molecules and lithium ions due to a charge transfer from cobalt nanoparticles to carbon, inducing the formation of amorphous lithium peroxide. The Full Paper itself is available at 10.1002/cssc.201500520.
Comparative genetic diversity in a sample of pony breeds from the U.K. and North America: a case study in the conservation of global genetic resources
Authors: Winton Clare L. , Plante Yves , Hind Pamela , McMahon Robert , Hegarty Matthew J. , McEwan Neil R. , Davies‐Morel Mina C. G. , Morgan Charly M. , Powell Wayne , Nash Deborah M.
Published: August 2015

Most species exist as subdivided ex situ daughter population(s) derived from a single original group of individuals. Such subdivision occurs for many reasons both natural and manmade. Traditional British and Irish pony breeds were introduced to North America (U.S.A. and Canada) within the last 150 years, and subsequently equivalent breed societies were established. We have analyzed selected U.K. and North American equivalent pony populations as a case study for understanding the relationship between putative source and derived subpopulations. Diversity was measured using mitochondrial DNA and a panel of microsatellite markers. Genetic signatures differed between the North American subpopulations according to historical management processes. Founder effect and stochastic drift was apparent, particularly pronounced in some breeds, with evidence of admixture of imported mares of different North American breeds. This demonstrates the importance of analysis of subpopulations to facilitate understanding the genetic effects of past management practices and to lead to informed future conservation strategies.
Hydroarylation of Alkynes with Phenols in the Presence of Gallium Complexes of a Labile N‐Ligand: Synthesis of Chromenes
Authors: Moskalev Mikhail V. , Yakub Arkadiy M. , Morozov Alexander G. , Baranov Evgenii V. , Kazarina Olga V. , Fedushkin Igor L.
Published: August 2015

In the presence of (dpp‐bian)Ga–Ga(dpp‐bian) (1) and [dpp‐bian(Ph)C=C(H)]Ga–Ga[(H)C=C(Ph)dpp‐bian] (2) {dpp‐bian = 1,2‐bis[(2,6‐diisopropylphenyl)imino]acenaphthene}, phenylacetylene reacts with 1‐naphthol to give 2‐(1‐phenylvinyl)naphthalen‐1‐ol (3). In solution in the presence of complexes 1 or 2, compound 3 undergoes further dimerization to give 2‐[4‐methyl‐2,4‐diphenyl‐3,4‐dihydro‐2H‐benzo[h]chromen‐2‐yl]naphthalen‐1‐ol (C36H28O2), whose diastereomers 4 and 5 were isolated in crystalline form. Diastereomer 4 is the kinetically favored product, which, however, undergoes conversion into diastereomer 5 in solution at elevated temperature. The structures of 4 and 5 were determined by single‐crystal X‐ray analysis. The catalytic activity of complexes 1 and 2 in the hydroarylation reactions of phenylacetylene and some other alkynes with different arenes has been investigated. By the reaction of phenylacetylene with 3,5‐di‐tert‐butylphenol, 5,7‐di‐tert‐butyl‐4‐methyl‐2,4‐diphenyl‐4H‐chromene (7) has been prepared for the first time.
Synthesis of (Arylamido)pyrrolidinone Libraries through Ritter‐Type Cascade Reactions of Dihydroxylactams
Authors: Wu Peng , Petersen Michael Åxman , Petersen Rico , Rasmussen Martin Ohsten , Bonnet Karine , Nielsen Thomas E. , Clausen Mads H.
Published: August 2015

The Ritter‐type reaction of arylnitriles and N‐acyliminium ions generated in situ from dihydroxy‐γ‐lactams gave tetrahydropyrrolo[2,3‐d]oxazol‐5‐ones in excellent yields. A subsequent acidic hydrolysis in EtOH/H2O/TFA (trifluoroacetic acid) yielded new (arylamido)pyrrolidinones with excellent cis diastereoselectivity. A combined one‐step Ritter–hydrolysis procedure proved to be of equal efficiency. This versatile method, which was successfully used for the construction of a screening library containing 706 molecules within the European Lead Factory consortium, provides a simple way to access new compounds incorporating an arylamido and a pyrrolidinone moiety, both of which are widely found in marketed drugs and in biologically active molecules.
Synthesis, Optical Rotation, and Absolute Configurations of Santinols
Authors: Wu Wen‐Ju , Chen Hui‐Jun , You Jun , Wu Yikang , Liu Bo
Published: August 2015

Santinols A1 and A2, two of the asymmetric 1,3‐diacylglycerols (1,3‐diacylglycerides) recently isolated from Helichrysum italicum subsp. microphyllum, were synthesized for the first time. The synthetic samples showed essentially the same 1H and 13C NMR spectra as reported for natural santinols. The optical rotations were also consistent with those for their natural counterparts, but only for less than an hour after the preparation of the sample solution; the sign of the optical rotation may reverse after a more prolonged time, revealing some so far unknown yet very interesting phenomena that deserve particular attention with regard to assignments of absolute configurations for asymmetric 1,3‐diacylglycerols by comparison of specific rotations. Also of interest is that acylation of the C‐2 OH groups in asymmetric 1,3‐diacylglycerols with 2‐(phenylamino)benzoic acid led to substantially “magnified” specific rotations and thus may help in characterization/identification and rapid estimation of the optical purities of asymmetric 1,3‐diacylglycerols.
Acetamidoarenediazonium Salts: Opportunities for Multiple Arene Functionali­zation
Authors: Schmidt Bernd , Elizarov Nelli , Riemer Nastja , Hölter Frank
Published: August 2015

Unlike their ortho counterparts, meta‐ and para‐acetamidoanilines can be converted into the corresponding acetamidoarenediazonium salts. These offer various opportunities for multiple Pd‐catalyzed arene functionalization reactions, such as Matsuda–Heck‐, Suzuki–Miyaura‐ or Fujiwara–Moritani couplings.
Square Wave Cathodic Adsorptive Stripping Voltammetric Determination of the Anticancer Drugs Flutamide and Irinotecan in Biological Fluids Using Renewable Pencil Graphite Electrodes
Authors: Temerk Yassien M. , Ibrahim Hossieny S. M. , Schuhmann Wolfgang
Published: August 2015

A sensitive electrochemical method based on square wave cathodic adsorptive stripping voltammetry (SWCASV) using pencil graphite electrodes (PGE) was developed for the individual and simultaneous determination of the anticancer drugs flutamide (Flu) and irinotecan (Irino) in biological fluids. Calibration curves showed an excellent linear response with limits of detection of 1.68×10−9 and 1.55×10−8 M Irino and Flu, respectively. The statistical evaluation of within‐day repeatability (n=5) and day to day precision (n=5) showed satisfactory accuracy and precision. SWCASV using a PGE for individual and simultaneous determination of both drugs in bulk form, human urine and serum samples was demonstrated.
Biomass‐derived hydrogen energy potential in Africa
Authors: Amuzu‐Sefordzi Basil , Huang Jingyu , Sowa Derrick M.A. , Baddoo Thelma Dede
Published: August 2015

Researchers in recent times have been looking at the promising potential of hydrogen energy. This potential when fully realized can help meet the growing global energy demand which has been as a result of population growth. In this context, hydrogen energy potential from the fuel wood and agricultural residue produced in African countries is assessed. This study analyses annual electricity consumption displacement when hydrogen energy is used for electrification purposes. The results show that Africa has the potential to produce a total of about 350,000 GWh of hydrogen energy from fuel wood and agricultural residue annually. Also, more than a 100% of the annual electricity consumption in West Africa can be displaced by hydrogen energy from these biomass resources. Annual motor‐gasoline consumption displacement and direct CO2 emission reductions as a result of using hydrogen energy are also studied in this article. This study is the first of its kind and serves as a baseline for the life cycle assessment of hydrogen energy technologies in Africa. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 289–297, 2016
Photocatalytic hydrogen evolution and decomposition of glycerol over Cd0.5Zn0.5S solid solution under visible light irradiation
Authors: Peng Shaoqin , Ding Min , Yi Ting , Zhan Zhikang , Li Yuexiang
Published: August 2015

Cd0.5Zn0.5S solid solutions were prepared by hydrothermal method and co‐precipitation method. The synthesized materials were characterized by means of X‐ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface area measurement and ultraviolet–visible diffuse reflectance spectra (UV–Vis DRS). The photocatalytic activity was tested in the reaction of hydrogen evolution from aqueous solutions of glycerol under visible light irradiation (λ ≥ 420 nm). Zn0.5Cd0.5S‐G prepared by co‐precipitation method with glycerol as solvent exhibits higher photocatalytic activity. This can be due to Zn0.5Cd0.5S‐G possessing higher surface area, which is beneficial to the adsorption of electron donor on catalyst surface. Glycerol improves notably photocatalytic hydrogen evolution with its simultaneous degradation. The possible mechanism of photocatalytic reaction for hydrogen evolution with simultaneous glycerol degradation was discussed preliminary. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 141–148, 2016
Thermal Imaging of Body Surface Temperature Distribution in Women with Anorexia Nervosa
Authors: Chudecka Monika , Lubkowska Anna
Published: August 2015

The drastic reduction in body weight observed in anorexia nervosa (AN) leads to various endocrine changes and consequently to disturbance in thermoregulation mechanisms and body temperature. Thermography allows for a noninvasive diagnosis of the distribution of skin surface temperatures, which is especially important for difficult patients such as women with AN, who are often very sensitive and difficult to treat. The main aim of this study was to measure the mean temperatures (Tmean) of selected body areas in young women diagnosed with AN and identify those areas where the temperature differences were particularly significant between healthy women and them. Additionally, we determined the relationships between body mass index, body composition (especially subcutaneous and VFM) and the value of mean surface temperature (Tmean) in AN woman. In the subjects with AN, Tmean of the abdomen, lower back and thighs were significantly higher than in the reference group, while Tmean of the hands were significantly lower. Among other things, analysis showed a significant negative correlation between Tmean of the abdomen, lower back and thighs, and the mass of subcutaneous and visceral fat. The lower Tmean of the hand was directly proportional to the reduced anthropomorphic parameters. The direct evaluation of body surface temperature distribution could provide clinical implications for the treatment of anorexic patients, including the potential use of thermotherapy in stimulating the circulatory system, especially in hypothermia, bradycardia and hypotension. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.
Fibroblast growth factor receptor 3 isoforms: Novel therapeutic targets for hepatocellular carcinoma?
Authors: Paur Jakob , Nika Lisa , Maier Christiane , Moscu‐Gregor Alexander , Kostka Julia , Huber Daniela , Mohr Thomas , Heffeter Petra , Schrottmaier Waltraud C. , Kappel Sonja , Kandioler Daniela , Holzmann Klaus , Marian Brigitte , Berger Walter , Grusch Michael , Grasl‐Kraupp Bettina
Published: August 2015

Fibroblast growth factor receptors (FGFRs) are frequently up‐regulated in subsets of hepatocellular carcinoma (HCC). Here, we provide mechanistic insight that FGFR3 splice variants IIIb and IIIc impact considerably on the malignant phenotype of HCC cells. The occurrence of FGFR3 variants was analyzed in human HCC samples. In hepatoma/hepatocarcinoma cell lines, FGFR3 isoforms were overexpressed by lentiviral constructs or down‐modulated by small interfering RNA (siRNA; affecting FGFR3‐IIIb and ‐IIIc) or an adenoviral kinase‐dead FGFR3‐IIIc construct (kdFGFR3). Elevated levels of FGFR3‐IIIb and/or ‐IIIc were found in 53% of HCC cases. FGFR3‐IIIb overexpression occurred significantly more often in primary tumors of large (pT2‐4) than of small size (pT1). Furthermore, one or both isoforms were enhanced mostly in cases with early tumor infiltration and/or recurrence at the time of surgery or follow‐up examinations. In hepatoma/hepatocarcinoma cells, up‐regulated FGFR3‐IIIb conferred an enhanced capability for proliferation. Both FGFR3‐IIIb and FGFR3‐IIIc suppressed apoptotic activity, enhanced clonogenic growth, and induced disintegration of the blood/lymph endothelium. The tumorigenicity of cells in severe combined immunodeficiency mice was augmented to a larger degree by variant IIIb than by IIIc. Conversely, siRNA targeting FGFR3 and kdFGFR3 reduced clonogenicity, anchorage‐independent growth, and disintegration of the blood/lymph endothelium in vitro. Furthermore, kdFGFR3 strongly attenuated tumor formation in vivo. Conclusions: Deregulated FGFR3 variants exhibit specific effects in the malignant progression of HCC cells. Accordingly, blockade of FGFR3‐mediated signaling may be a promising therapeutic approach to antagonize growth and malignant behavior of HCC cells.(Hepatology 2015;62:1767–1778)
Jagged1 heterozygosity in mice results in a congenital cholangiopathy which is reversed by concomitant deletion of one copy of Poglut1 (Rumi)
Authors: Thakurdas Shakeel M. , Lopez Mario F. , Kakuda Shinako , Fernandez‐Valdivia Rodrigo , Zarrin‐Khameh Neda , Haltiwanger Robert S. , Jafar‐Nejad Hamed
Published: August 2015

Haploinsufficiency for the Notch ligand JAG1 in humans results in an autosomal‐dominant, multisystem disorder known as Alagille syndrome, which is characterized by a congenital cholangiopathy of variable severity. Here, we show that on a C57BL/6 background, jagged1 heterozygous mice (Jag1+/−
) exhibit impaired intrahepatic bile duct (IHBD) development, decreased SOX9 expression, and thinning of the periportal vascular smooth muscle cell (VSMC) layer, which are apparent at embryonic day 18 and the first postnatal week. In contrast, mice double heterozygous for Jag1 and the glycosyltransferase, Poglut1 (Rumi), start showing a significant improvement in IHBD development and VSMC differentiation during the first week. At P30, Jag1+/−
mice show widespread ductular reactions and ductopenia in liver and a mild, but statistically, significant bilirubinemia. In contrast, P30 Jag1/Rumi double‐heterozygous mice show well‐developed portal triads around most portal veins, with no elevation of serum bilirubin. Conditional deletion of Rumi in VSMCs results in progressive arborization of the IHBD tree, whereas deletion of Rumi in hepatoblasts frequently results in an increase in the number of hepatic arteries without affecting bile duct formation. Nevertheless, removing one copy of Rumi from either VSMCs or hepatoblasts is sufficient to partially suppress the Jag1+/−
bile duct defects. Finally, all Rumi target sites of the human JAG1 are efficiently glucosylated, and loss of Rumi in VSMCs results in increased levels of full‐length JAG1 and a shorter fragment of JAG1 without affecting Jag1 messenger RNA levels. Conclusions: On a C57BL/6 background, Jag1 haploinsufficiency results in bile duct paucity in mice. Removing one copy of Rumi suppresses the Jag1+/−
bile duct phenotype, indicating that Rumi opposes JAG1 function in the liver. (Hepatology 2016;63:550–565)
Relational learning and transitive expression in aging and amnesia
Authors: Ryan Jennifer D. , D'Angelo Maria C. , Kamino Daphne , Ostreicher Melanie , Moses Sandra N. , Rosenbaum R. Shayna
Published: August 2015

Aging has been associated with a decline in relational memory, which is critically supported by the hippocampus. By adapting the transitivity paradigm(Bunsey and Eichenbaum (1996) Nature 379:255‐257), which traditionally has been used in nonhuman animal research, this work examined the extent to which aging is accompanied by deficits in relational learning and flexible expression of relational information. Older adults' performance was additionally contrasted with that of amnesic case DA to understand the critical contributions of the medial temporal lobe, and specifically, the hippocampus, which endures structural and functional changes in healthy aging. Participants were required to select the correct choice item (B versus Y) based on the presented sample item (e.g., A). Pairwise relations must be learned (A‐>B, B‐>C, C‐>D) so that ultimately, the correct relations can be inferred when presented with a novel probe item (A‐>C?Z?). Participants completed four conditions of transitivity that varied in terms of the degree to which the stimuli and the relations among them were known pre‐experimentally. Younger adults, older adults, and DA performed similarly when the condition employed all pre‐experimentally known, semantic, relations. Older adults and DA were less accurate than younger adults when all to‐be‐learned relations were arbitrary. However, accuracy improved for older adults when they could use pre‐experimentally known pairwise relations to express understanding of arbitrary relations as indexed through inference judgments. DA could not learn arbitrary relations nor use existing knowledge to support novel inferences. These results suggest that while aging has often been associated with an emerging decline in hippocampal function, prior knowledge can be used to support novel inferences. However, in case DA, significant damage to the hippocampus likely impaired his ability to learn novel relations, while additional damage to ventromedial prefrontal and anterior temporal regions may have resulted in an inability to use prior knowledge to flexibly express indirect relational knowledge.© 2015 The Authors Hippocampus Published by Wiley Periodicals, Inc.