bluuebunny/crossref_metadata_2025 huggingface dataset:
Annual bank and point bar morphodynamics of a meandering river determined by high‐accuracy multitemporal laser scanning and flow data
Authors: Lotsari E. , Vaaja M. , Flener C. , Kaartinen H. , Kukko A. , Kasvi E. , Hyyppä H. , Hyyppä J. , Alho P.
Published: June 2014

The knowledge has been insufficient concerning the effects of peak flows, and local bend and flow characteristics on annual morphodynamics of consecutive bends in meandering rivers. Therefore, it was determined how flow peak magnitude and duration affect morphodynamics, how the short‐term spatial evolution of a given meander bend associates with the neighboring bends, and how local bend and flow characteristics affect morphodynamics. The annual bank and point bar morphodynamics of eight consecutive bends of a subarctic meandering river were analyzed between 2009 and 2012 on the basis of high‐accuracy multitemporal data, measured by mobile and terrestrial laser scanning and an Acoustic Doppler Current Profiler. According to the results, multiple years of highly accurate data are crucial for a broader picture of meandering channel evolution. The results showed for the first time in detail that none of the years were similar in terms of point bar and bank morphodynamics. The duration of point bar submergence and maximum water stage was more important for evolution of the meandering channel than the local effects of each bend. The detailed topographical data of the present study confirmed that the higher the flow and water stage peak the more deposition occurred on point bars. More importantly, the independence of the short‐term spatial evolution of meander bends from the association with neighboring bends was confirmed. Erosion patterns did not relate particularly to the sinuosity or radius of curvature. A clear relation between velocity and bend curvature, on which some meander migration models rely, was not found.
Interior Secretary Highlights Key Trends, Including Climate Change and Fiscal Constraint
Authors: Showstack Randy
Published: June 2014

Climate change is “the defining issue of our time,” Department of the Interior (DOI) Secretary Sally Jewell said during her 18 June keynote addess at the AGU Science Policy Conference in Washington, D. C. The United States has to “lead by example. We can't be the largest economy in the world and the second largest producer of carbon in the world”—after China—“and not take care of our own problems first to demonstrate to the world what needs to be done,” she said.
Features of amplitude and Doppler frequency variation of ELF/VLF waves generated by “beat‐wave” HF heating at high latitudes
Authors: Tereshchenko E. D. , Shumilov O. I. , Kasatkina E. A. , Gomonov A. D.
Published: June 2014

Observations of extremely low frequency (ELF, 3–3000 Hz) radio waves generated by a “beat‐wave” (BW) high frequency (~ 4.04–4.9 MHz) ionospheric heating are presented. ELF waves were registered with the ELF receiver located at Lovozero (68°N, 35°E), 660 km east from the European Incoherent Scatter Tromso heating facility (69.6°N, 19.2°E). Frequency shifts between the generated beat‐wave and received ELF waves were detected in all sessions. It is shown that the amplitudes of ELF waves depend on the auroral electrojet current strength. Our results showing a strong dependence of ELF signal intensities on the substorm development seem to support the conclusion that electrojet currents may affect the BW generation of ELF/VLF waves.
Spin crossover in Fe2SiO4 liquid at high pressure
Authors: Ramo David Muñoz , Stixrude Lars
Published: June 2014

We combine spin‐polarized density functional theory with first principle molecular dynamics (FPMD) to study the spin crossover in liquid Fe2SiO4, up to 300 GPa and 6000 K. In contrast to the much sharper transition seen in crystals, we find that the high‐ to low‐spin transition occurs over a very broad pressure interval (>200 GPa) due to structural disorder in the liquid. We find excellent agreement with the experimental Hugoniot. We combine our results with previous FPMD calculations to derive the partial molar volumes of the oxide components MgO, FeO, and SiO2. We find that eutectic melts in the MgO‐FeO‐SiO2 system are denser than coexisting solids in the bottom 600 km of Earth's mantle.
Slip rates and spatially variable creep on faults of the northern San Andreas system inferred through Bayesian inversion of Global Positioning System data
Authors: Murray Jessica R. , Minson Sarah E. , Svarc Jerry L.
Published: June 2014

Fault creep, depending on its rate and spatial extent, is thought to reduce earthquake hazard by releasing tectonic strain aseismically. We use Bayesian inversion and a newly expanded GPS data set to infer the deep slip rates below assigned locking depths on the San Andreas, Maacama, and Bartlett Springs Faults of Northern California and, for the latter two, the spatially variable interseismic creep rate above the locking depth. We estimate deep slip rates of 21.5 ± 0.5, 13.1 ± 0.8, and 7.5 ± 0.7 mm/yr below 16 km, 9 km, and 13 km on the San Andreas, Maacama, and Bartlett Springs Faults, respectively. We infer that on average the Bartlett Springs fault creeps from the Earth's surface to 13 km depth, and below 5 km the creep rate approaches the deep slip rate. This implies that microseismicity may extend below the locking depth; however, we cannot rule out the presence of locked patches in the seismogenic zone that could generate moderate earthquakes. Our estimated Maacama creep rate, while comparable to the inferred deep slip rate at the Earth's surface, decreases with depth, implying a slip deficit exists. The Maacama deep slip rate estimate, 13.1 mm/yr, exceeds long‐term geologic slip rate estimates, perhaps due to distributed off‐fault strain or the presence of multiple active fault strands. While our creep rate estimates are relatively insensitive to choice of model locking depth, insufficient independent information regarding locking depths is a source of epistemic uncertainty that impacts deep slip rate estimates.
Global assessment of OMI aerosol single‐scattering albedo using ground‐based AERONET inversion
Authors: Jethva Hiren , Torres Omar , Ahn Changwoo
Published: June 2014

We compare the aerosol single‐scattering albedo (SSA) retrieved by the near‐UV two‐channel algorithm (OMAERUV) applied to the Aura/Ozone Monitoring Instrument (OMI) measurements with an equivalent inversion made by the ground‐based Aerosol Robotic Network (AERONET). A recent upgrade of the OMAERUV algorithm incorporates a modified carbonaceous aerosol model, a Cloud‐Aerosol Lidar with Orthogonal Polarization‐based aerosol height climatology, and a robust aerosol‐type identification. This paper is the first comprehensive effort to globally compare the OMI‐retrieved SSA with that of AERONET using all available sites spanning the regions of biomass burning, dust, and urban pollution. An analysis of the colocated retrievals over 269 sites reveals that about 46% (69%) of OMI‐AERONET matchups agree within the absolute difference of ±0.03 (±0.05) for all aerosol types. The comparison improves to 52% (77%) when only “smoke” and “dust” aerosol types were identified by the OMAERUV algorithm. Regionally, the agreement between the two inversions was robust over the biomass burning sites of South America, Sahel, Indian subcontinent, and oceanic/coastal sites followed by a reasonable agreement over Northeast Asia. Over the desert regions, OMI tends to retrieve higher SSA, particularly over the Arabian Peninsula. Globally, the OMI‐AERONET matchups agree mostly within ±0.03 for the aerosol optical depth (440 nm) and UV‐aerosol index larger than 0.4 and 1.0, respectively. Possible sources of uncertainty in the OMI retrieval can be the subpixel cloud contamination, assumptions of the surface albedo, and spectral aerosol absorption. We expect further refinement in the OMAERUV algorithm which stands uniquely in characterizing aerosol absorption from space.
Development and Application of Multi‐Scale Numerical Tool to Modeling Pneumatic Ventricular Assist Devices with Increased Athrombogenicity
Authors: Kopernik Magdalena
Published: June 2014

The multi‐scale numerical model of blood chamber of ventricular assist device (VAD) with deposited a biocompatible titanium nitride (TiN) nano‐coating is introduced. The model is developed to optimize shape parameters of the blood chamber and to determine fracture parameters of the nano‐coating. The development of finite element (FE) macro‐model is combined with a digital image correlation data to validate a computed strain state. Contrary, on a micro‐scale calibration and validation of a representative volume element (RVE) model of the wall of VAD composed of the TiN coating and substrate‐polymer is realized by comparison with results of an experimental in situ SEM's micro‐tensile test. The multi‐scale model of VAD is enriched with materials research. Thus, tensile tests of VADs’ polymers are performed to obtain the properties of designed materials of the VADs. On the other hand, on a micro‐scale, the properties of TiN are identified based on a nanoindentation test and an inverse analysis for its interpretation. The profilometric studies and analytical model are presented to calculate a residual stress in the TiN. The final result of the paper is the multi‐scale numerical tool to modeling pneumatic VADs with increased biocompatibility produced in Poland.
Construction of White‐Light‐Emitting Silk Protein Hybrid Films by Molecular Recognized Assembly among Hierarchical Structures
Authors: Lin Naibo , Hu Fan , Sun Yilin , Wu Chenxu , Xu Hongyao , Liu Xiang Yang
Published: June 2014

The fabrication of bio‐hybrid functional films is demonstrated by applying a materials assembly technique. Based on the hierarchical structures of silk fibroin materials, functional molecular/materials, i.e., quantum dots (QDs), can be fixed to amino acid groups in silk fibroin films. It follows that white‐light‐emitting QD silk hybrid films are obtained by hydrogen bond molecular recognition to the –COO– groups functionalized to blue luminescent ZnSe (5.2 nm) and yellow luminescent CdTe (4.1 nm) QDs in a molar ratio of 30:1 of ZnSe to CdTe QDs. Simultaneously, a systematic blue shift in the emission peak is observed from the QD solution to QDs silk fibroin films. The significant blue shift hints the appearance of the strong interaction between QDs and silk fibroins, which causes strong white‐light‐emitting uniform silk films. The molecular recognized interactions are confirmed by high resolution transmission electron microscopy, field scanning electron microscope, and attenuated total internal reflectance Fourier transform infrared spectroscopy. The QD silk films show unique advantages, including simple preparation, tunable white‐light emission, easy manipulation, and low fabrication costs, which make it a promising candidate for multicomponent optodevices.
Large, Temperature‐Tunable Low‐Field Magnetoresistance in La0.7Sr0.3MnO3:NiO Nanocomposite Films Modulated by Microstructures
Authors: Ning Xingkun , Wang Zhanjie , Zhang Zhidong
Published: June 2014

Magnetic properties and low‐field magnetoresistance (LFMR) in La0.7Sr0.3MnO3 (LSMO):NiO nanocomposite films grown on SrTiO3 (001) substrates, which are shown to be tunable with different microstructures, are investigated. The LSMO:NiO nanocomposite films with NiO volume ratio of 50% have a checkerboard‐like structure and show a large LFMR in a temperature range from 200 to 300 K (≈17% at 250 K with a magnetic field of 1 T). As the NiO volume ratio is increased to 70%, a nano‐columnar structure formed in the films. Their LFMR is significantly enhanced at a wide temperature range of 10–210 K. The highest value of LFMR with 41% is achieved at 10 K in a magnetic field of 1 T. The enhanced LFMR can be considered to result from the electron scattering at the ferromagnetic LSMO/NiO interfaces and magnetic tunnel junctions (MTJs) of LSMO/NiO/LSMO at the nanometer scale. These results demonstrate that large and tunable LFMR from low temperature to room temperature can be realized by controlling the microstructures in the epitaxial La0.7Sr0.3MnO3:NiO nano­composite thin films, which will be expected to be applied in the devices using for a wide temperature range.
3D Culture of Tonsil‐Derived Mesenchymal Stem Cells in Poly(ethylene glycol)‐Poly(l‐alanine‐co‐l‐phenyl alanine) Thermogel
Authors: Park Min Hee , Yu Yeonsil , Moon Hyo Jung , Ko Du Young , Kim Han Su , Lee Hyukjin , Ryu Kyung Ha , Jeong Byeongmoon
Published: June 2014

Poly(ethylene glycol)‐poly(l‐alanine‐co‐l‐phenyl alanine) (PEG‐PAF) aqueous solutions undergo sol‐to‐gel transition as the temperature increases. The transition is driven by the micelle aggregation involving the partial dehydration of the PEG block and the partial increase in β‐sheet content of the PAF block. Tonsil‐tissue‐derived mesenchymal stem cells (TMSCs), a new stem cell resource, are encapsulated through the sol‐to‐gel transition of the TMSC‐suspended PEG‐PAF aqueous solutions. The encapsulated TMSCs are in vitro 3D cultured by using induction media supplemented with adipogenic, osteogenic, or chondrogenic factors, where the TMSCs preferentially undergo chondrogenesis with high expressions of type II collagen and sulfated glycosaminoglycan. As a feasibility study of the PEG‐PAF thermogel for injectable tissue engineering, the TMSCs encapsulated in hydrogels are implanted in the subcutaneous layer of mice by injecting the TMSC suspended PEG‐PAF aqueous solution. The in vivo studies also prove that TMSCs undergo chondrogenesis with high expression of the chondrogenic biomarkers. This study suggests that the TMSCs can be an excellent resource of MSCs, and the thermogelling PEG‐PAF is a promising injectable tissue engineering scaffold, particularly for chondrogenic differentiation of the stem cells.
Bioinspired Fabrication of High‐Quality 3D Artificial Compound Eyes by Voxel‐Modulation Femtosecond Laser Writing for Distortion‐Free Wide‐Field‐of‐View Imaging
Authors: Wu Dong , Wang Jian‐Nan , Niu Li‐Gang , Zhang Xu Lin , Wu Si Zhu , Chen Qi‐Dai , Lee Luke P. , Sun Hong Bo
Published: June 2014

The small field‐of‐view (FOV) limits the range of vision in various detecting/imaging devices from biological microscopes to commercial cameras and military radar. To date, imaging with FOV over 90° has been realized with fish‐eye lenses, catadioptric lens, and rotating cameras. However, these devices suffer from inherent imaging distortion and require multiple bulky elements. Inspired by compound eyes found in nature, here a small‐size (84 μm), distortion‐free, wide‐FOV imaging system is presented via an advanced 3D artificial eye architecture. The 3D artificial eye structure is accomplished by exploiting an effective optical strategy — high‐speed voxel‐modulation laser scanning (HVLS). The eye features a hexagonal shape, high fill factor (FF) (100%), large numerical aperture (NA) (0.4), ultralow surface roughness (2.5 nm) and aspherical profile, which provides high uniformity optics (error < ±6%) and constant resolution (FWHM = 1.7 ± 0.1 μm) in all directions. Quantitative measurement shows the eye reduces imaging distortion by two/three times under 30°/45° incidence, compared with a single lens. The distortion‐free FOV can be controlled from 30° to 90°.
Cutis laxa with pulmonary emphysema, conjunctivochalasis, nasolacrimal duct obstruction, abnormal hair, and a novel FBLN5 mutation
Authors: Kantaputra Piranit Nik , Kaewgahya Massupa , Wiwatwongwana Atchareeya , Wiwatwongwana Damrong , Sittiwangkul Rekwan , Iamaroon Anak , Dejkhamron Prapai
Published: June 2014

We report on a 4‐year‐old girl with autosomal recessive cutis laxa, type IA, or pulmonary emphysema type (ARCL1A; OMIM #219100), with loose and wrinkled skin, mitral and tricuspid valve prolapse, conjunctivochalasis, obstructed nasolacrimal ducts, hypoplastic maxilla, and early childhood‐onset pulmonary emphysema. Mutation analysis of FBLN5 showed a homozygous c.432C>G missense mutation, and heterozygosity in the parents. This is predicted to cause amino acid substitution p.Cys144Trp. Conjunctivochalasis or redundant folds of conjunctiva and obstructed nasolacrimal ducts have not been reported to be associated with FBLN5 mutations. Histopathological study of the conjunctival biopsy showed that most blood vessels had normal elastic fibers. The gingiva appeared normal, but histologically elastic fibers were defective. Scanning electron micrography of scalp hair demonstrated hypoplastic hair follicles. The cuticles appear intact underneath the filamentous meshwork. © 2014 Wiley Periodicals, Inc.
Synthesis and Properties of Lanthanide Ruthenium(III) Oxide Perovskites
Authors: Sinclair Alexandra , Rodgers Jennifer A. , Topping Craig V. , Míšek Martin , Stewart Ross D. , Kockelmann Winfried , Bos Jan‐Willem G. , Attfield J. Paul
Published: June 2014

An extensive series of new LnRuO3 perovskites has been synthesized at high pressure. These ruthenium(III)‐based oxides are ruthenium deficient, and high‐pressure samples have compositions close to LnRu0.9O3. These phases stabilize ruthenium(III) which is very unusual in oxides. X‐ray and neutron powder diffraction studies show that the materials adopt orthorhombic perovskite superstructures in which the RuO6 octahedra are tetragonally compressed. These distortions, and the Mott insulator properties of the materials, are driven by strong spin‐orbit coupling.
Strontium Vanadium Oxide–Hydrides: “Square‐Planar” Two‐Electron Phases
Authors: Denis Romero Fabio , Leach Alice , Möller Johannes S. , Foronda Francesca , Blundell Stephen J. , Hayward Michael A.
Published: June 2014

A series of strontium vanadium oxide–hydride phases prepared by utilizing a low‐temperature synthesis strategy in which oxide ions in Srn+1VnO3n+1 (n=∞, 1, 2) phases are topochemically replaced by hydride ions to form SrVO2H, Sr2VO3H, and Sr3V2O5H2, respectively. These new phases contain sheets or chains of apex‐linked V3+O4 squares stacked with SrH layers/chains, such that the n=∞ member, SrVO2H, can be considered to be analogous to “infinite‐layer” phases, such as Sr1−xCaxCuO2 (the parent phase of the high‐Tc cuprate superconductors), but with a d2 electron count. All three oxide–hydride phases exhibit strong antiferromagnetic coupling, with SrVO2H exhibiting an antiferromagnetic ordering temperature, TN>300 K. The strong antiferromagnetic couplings are surprising given they appear to arise from π‐type magnetic exchange.
Structurally Homogeneous Nanosheets from Self‐Assembly of a Collagen‐Mimetic Peptide
Authors: Jiang Tao , Xu Chunfu , Zuo Xiaobing , Conticello Vincent P.
Published: June 2014

A collagen‐mimetic peptide, NSIII, has been designed with three sequential blocks having positive, neutral, and negative charges, respectively. The non‐canonical imino acid, (2S,4S)‐4‐aminoproline (amp), was used to specify the positive charges at the Xaa positions of (Xaa‐Yaa‐Gly) triads in the N‐terminal domain of NSIII. Peptide NSIII underwent self‐assembly from aqueous solution to form a highly homogeneous population of nanosheets. Two‐dimensional crystalline sheets formed in which the length of the peptide defined the height of the sheets. These results contrasted with prior results on a similar multi‐domain collagen‐mimetic polypeptides in which the sheets had highly polydisperse distribution of sizes in the (x/y)‐ and (z)‐dimensions. The structural differences between the two nanosheet assemblies were interpreted in terms of the relative stereoelectronic effects of the different aminoproline derivatives on the local triple helical conformation of the peptides.
Synthesis of a Specified, Silica Molecular Sieve by Using Computationally Predicted Organic Structure‐Directing Agents
Authors: Schmidt Joel E. , Deem Michael W. , Davis Mark E.
Published: June 2014

Crystalline molecular sieves are used in numerous applications, where the properties exploited for each technology are the direct consequence of structural features. New materials are typically discovered by trial and error, and in many cases, organic structure‐directing agents (OSDAs) are used to direct their formation. Here, we report the first successful synthesis of a specified molecular sieve through the use of an OSDA that was predicted from a recently developed computational method that constructs chemically synthesizable OSDAs. Pentamethylimidazolium is computationally predicted to have the largest stabilization energy in the STW framework, and is experimentally shown to strongly direct the synthesis of pure‐silica STW. Other OSDAs with lower stabilization energies did not form STW. The general method demonstrated here to create STW may lead to new, simpler OSDAs for existing frameworks and provide a way to predict OSDAs for desired, theoretical frameworks.
Discovery and Application of Doubly Quaternized Cinchona‐Alkaloid‐Based Phase‐Transfer Catalysts
Authors: Xiang Bangping , Belyk Kevin M. , Reamer Robert A. , Yasuda Nobuyoshi
Published: June 2014

We report the discovery of novel N,N′‐disubstituted cinchona alkaloids as efficient phase‐transfer catalysts for the assembly of stereogenic quaternary centers. In comparison to traditional cinchona‐alkaloid‐based phase‐transfer catalysts, these new catalysts afford substantial improvements in enantioselectivity and reaction rate for intramolecular spirocyclization reactions with catalyst loadings as low as 0.3 mol % under mild conditions.
Pure In‐Phase Heteronuclear Correlation NMR Experiments
Authors: Castañar Laura , Saurí Josep , Williamson Robert Thomas , Virgili Albert , Parella Teodor
Published: June 2014

A general NMR approach to provide pure in‐phase (PIP) multiplets in heteronuclear correlation experiments is described. The implementation of a zero‐quantum filter efficiently suppresses any unwanted anti‐phase contributions that usually distort the multiplet pattern of cross‐peaks and can hamper their analysis. The clean pattern obtained in PIP‐HSQMBC experiments is suitable for a direct extraction of coupling constants in resolved signals, for a peak‐fitting process from a reference signal, and for the application of the IPAP technique in non‐resolved multiplets.
Temperature‐ and Voltage‐Induced Ligand Rearrangement of a Dynamic Electroluminescent Metallopolymer
Authors: Asil Demet , Foster Jonathan A. , Patra Asit , de Hatten Xavier , del Barrio Jesús , Scherman Oren A. , Nitschke Jonathan R. , Friend Richard H.
Published: June 2014

A dynamic‐covalent metal‐containing polymer was synthesized by the condensation of linear diamine and dialdehyde subcomponents around copper(I) templates in the presence of bidentate phosphine ligands. In solution, the red polymers undergo a sol–gel transition upon heating to form a yellow gel, a process that can be either reversible or irreversible depending on the solvent used. When fabricated into a light‐emitting electrochemical cell (LEC), the polymer emits infrared light at low voltage. As the voltage is increased, a blue shift in the emission wavelength is observed until yellow light is emitted, a process which is gradually reversed over time upon lowering the voltage. The mechanism underlying these apparently disparate responses is deduced to be due to loss of the copper phosphine complex from the polymer.
Functionalization of Alkynes by a (Salen)ruthenium(VI) Nitrido Complex
Authors: Man Wai‐Lun , Xie Jianhui , Lo Po‐Kam , Lam William W. Y. , Yiu Shek‐Man , Lau Kai‐Chung , Lau Tai‐Chu
Published: June 2014

Exploring new reactivity of metal nitrides is of great interest because it can give insights to N2 fixation chemistry and provide new methods for nitrogenation of organic substrates. In this work, reaction of a (salen)ruthenium(VI) nitrido complex with various alkynes results in the formation of novel (salen)ruthenium(III) imine complexes. Kinetic and computational studies suggest that the reactions go through an initial ruthenium(IV) aziro intermediate, followed by addition of nucleophiles to give the (salen)ruthenium(III) imine complexes. These unprecedented reactions provide a new pathway for nitrogenation of alkynes based on a metal nitride.
Continuous Flow Synthesis of Ketones from Carbon Dioxide and Organolithium or Grignard Reagents
Authors: Wu Jie , Yang Xiaoqing , He Zhi , Mao Xianwen , Hatton T. Alan , Jamison Timothy F.
Published: June 2014

We describe an efficient continuous flow synthesis of ketones from CO2 and organolithium or Grignard reagents that exhibits significant advantages over conventional batch conditions in suppressing undesired symmetric ketone and tertiary alcohol byproducts. We observed an unprecedented solvent‐dependence of the organolithium reactivity, the key factor in governing selectivity during the flow process. A facile, telescoped three‐step–one‐flow process for the preparation of ketones in a modular fashion through the in‐line generation of organometallic reagents is also established.
Discovery of Cell‐Permeable Inhibitors That Target the BRCT Domain of BRCA1 Protein by Using a Small‐Molecule Microarray
Authors: Na Zhenkun , Pan Sijun , Uttamchandani Mahesh , Yao Shao Q.
Published: June 2014

BRCTs are phosphoserine‐binding domains found in proteins involved in DNA repair, DNA damage response and cell cycle regulation. BRCA1 is a BRCT domain‐containing, tumor‐suppressing protein expressed in the cells of breast and other human tissues. Mutations in BRCA1 have been found in ca. 50 % of hereditary breast cancers. Cell‐permeable, small‐molecule BRCA1 inhibitors are promising anticancer agents, but are not available currently. Herein, with the assist of microarray‐based platforms, we have discovered the first cell‐permeable protein–protein interaction (PPI) inhibitors against BRCA1. By targeting the (BRCT)2 domain, we showed compound 15 a and its prodrug 15 b inhibited BRCA1 activities in tumor cells, sensitized these cells to ionizing radiation‐induced apoptosis, and showed synergistic inhibitory effect when used in combination with Olaparib (a small‐molecule inhibitor of poly‐ADP‐ribose polymerase) and Etoposide (a small‐molecule inhibitor of topoisomerase II). Unlike previously reported peptide‐based PPI inhibitors of BRCA1, our compounds are small‐molecule‐like and could be directly administered to tumor cells, thus making them useful for future studies of BRCA1/PARP‐related pathways in DNA damage and repair response, and in cancer therapy.
The Intermetalloid Cluster [(Cp*AlCu)6H4], Embedding a Cu6 Core Inside an Octahedral Al6 Shell: Molecular Models of Hume–Rothery Nanophases
Authors: Ganesamoorthy Chelladurai , Weßing Jana , Kroll Clarissa , Seidel Rüdiger W. , Gemel Christian , Fischer Roland A.
Published: June 2014

Defined molecular models for the surface chemistry of Hume–Rothery nanophases related to catalysis are very rare. The Al‐Cu intermetalloid cluster [(Cp*AlCu)6H4] was selectively obtained from the clean reaction of [(Cp*Al)4] and [(Ph3PCuH)6]. The stronger affinity of Cp*Al towards Cu sweeps the phosphine ligands from the copper hydride precursor and furnishes an octahedral Al6 cage to encapsulate the Cu6 core. The resulting hydrido cluster M12H4 reacts with benzonitrile to give the stoichiometric hydrometalation product [(Cp*AlCu)6H3(N=CHPh)].
Chemistry with Graphene and Graphene Oxide—Challenges for Synthetic Chemists
Authors: Eigler Siegfried , Hirsch Andreas
Published: June 2014

The chemical production of graphene as well as its controlled wet chemical modification is a challenge for synthetic chemists. Furthermore, the characterization of reaction products requires sophisticated analytical methods. In this Review we first describe the structure of graphene and graphene oxide and then outline the most important synthetic methods that are used for the production of these carbon‐based nanomaterials. We summarize the state‐of‐the‐art for their chemical functionalization by noncovalent and covalent approaches. We put special emphasis on the differentiation of the terms graphite, graphene, graphite oxide, and graphene oxide. An improved fundamental knowledge of the structure and the chemical properties of graphene and graphene oxide is an important prerequisite for the development of practical applications.
One Hundred Years of the Max‐Planck‐Institut für Kohlenforschung
Authors: Reetz Manfred T.
Published: June 2014

This Essay is an account of the institutional and scientific development of the Max‐Planck‐Institut für Kohlenforschung in Mülheim an der Ruhr (Germany), which is the successor to the Kaiser‐Wilhelm‐Institut für Kohlenforschung founded in 1914. The Essay is divided into four main parts, corresponding to the four major periods which are closely associated with the respective Directors of the Institute from 1914 to 2014: 1) Franz Fischer; 2) Karl Ziegler; 3) Günther Wilke; and 4) the period beginning with Manfred T. Reetz, who established a directorate comprising five Directors of equal status, each heading a different research department under the banner of catalysis. Along with key historical events associated with the Institute, research highlights of the four periods are featured.
Synchronization of Two Assembly Processes To Build Responsive DNA Nanostructures
Authors: Nie Zhou , Wang Pengfei , Tian Cheng , Mao Chengde
Published: June 2014

Herein, we report a strategy for the synchronization of two self‐assembly processes to assemble stimulus‐responsive DNA nanostructures under isothermal conditions. We hypothesized that two independent assembly processes, when brought into proximity in space, could be synchronized and would exhibit positive synergy. To demonstrate this strategy, we assembled a ladderlike DNA nanostructure and a ringlike DNA nanostructure through two hybridization chain reactions (HCRs) and an HCR in combination with T‐junction cohesion, respectively. Such proximity‐induced synchronization adds a new element to the tool box of DNA nanotechnology. We believe that it will be a useful approach for the assembly of complex and responsive nanostructures.
Nanojunction‐Mediated Photocatalytic Enhancement in Heterostructured CdS/ZnO, CdSe/ZnO, and CdTe/ZnO Nanocrystals
Authors: Eley Clive , Li Tong , Liao Fenglin , Fairclough Simon Michael , Smith Jason M. , Smith George , Tsang Shik Chi Edman
Published: June 2014

A series of highly efficient semiconductor nanocrystal (NC) photocatalysts have been synthesized by growing wurtzite‐ZnO tetrahedrons around pre‐formed CdS, CdSe, and CdTe quantum dots (QDs). The resulting contact between two small but high‐quality crystals creates novel CdX/ZnO heterostructured semiconductor nanocrystals (HSNCs) with extensive type‐II nanojunctions that exhibit more efficient photocatalytic decomposition of aqueous organic molecules under UV irradiation. Catalytic testing and characterization indicate that catalytic activity increases as a result of a combination of both the intrinsic chemistry of the chalcogenide anions and the heterojunction structure. Atomic probe tomography (APT) is employed for the first time to probe the spatial characteristics of the nanojunction between cadmium chalcogenide and ZnO crystalline phases, which reveals various degrees of ion exchange between the two crystals to relax large lattice mismatches. In the most extreme case, total encapsulation of CdTe by ZnO as a result of interfacial alloying is observed, with the expected advantage of facilitating hole transport for enhanced exciton separation during catalysis.
One‐, Two‐, and Three‐Electron Reduction of a Cyclic Alkyl(amino)carbene–SbCl3 Adduct
Authors: Kretschmer Robert , Ruiz David A. , Moore Curtis E. , Rheingold Arnold L. , Bertrand Guy
Published: June 2014

A cyclic alkyl(amino)carbene readily reacts with SbCl3 to form the corresponding SbIII adduct. One‐electron reduction gives rise to the first example of a neutral antimony‐centered radical characterized in solution. Two‐electron reduction affords a Lewis base stabilized chloro‐stibinidene, whereas three‐electron reduction gives an antimony diatomic species capped by two carbenes. The radical has been characterized by EPR spectroscopy, while the structure of the other three species has been ascertained by single‐crystal X‐ray diffraction. In these four species, the formal oxidation state of the metalloid diminishes from III, to II, to I, and finally 0.
New chiral diphosphoramidite rhodium(I) complexes for asymmetric hydrogenation
Authors: Drommi Dario , Micalizzi Giuseppe , Arena Carmela Grazia
Published: June 2014

Chiral 1,5‐cyclooctadiene rhodium(I) cationic complexes with C2‐symmetric chelate diphosphoramidite ligands containing (R,R)‐1,2‐diaminocyclohexane as the backbone and two atropoisomeric biaryl units were easily synthesized and fully characterized by multinuclear one‐ and two‐dimensional NMR spectroscopy and elemental analysis. These complexes were used as catalysts in the asymmetric hydrogenation of dimethyl itaconate, methyl 2‐acetamidoacrylate and (Z)‐methyl‐2‐acetamido‐3‐phenylacrylate. The rhodium complexes derived from diphosphoramidite ligands that contain two (R) or (S) BINOL (2,2′‐dihydroxy‐1,1′‐binaphthyl) units proved to be efficient catalysts, giving complete conversion and very good enantioselectivity (up to 88% ee). An uncommon positive H2 pressure effect on the enantioselectivity was observed in the hydrogenation of dimethyl itaconate catalyzed by Rh‐complex with diphosphoramidite ligand that contains two (S)‐binaphthol moieties. Copyright © 2014 John Wiley & Sons, Ltd.
A New Regional Cold War?American andChinese Posturing in thePacific
Authors: Ratuva Steven
Published: June 2014

It is often argued that theUnitedStates andChinese engagement in thePacific manifests a clash of foreign policies that mimics the cold war confrontation of the post‐WorldWar II era. The article argues that rather than a dichotomous contestation of foreign policies, theUnitedStates–China engagement is more complex in nature and needs to be understood using more ‘syncretic’ lenses to understand the complex synergy in their relationship, which oscillates between tension and accommodation, cooperation and competition. While there are areas of policy contestation, there are also areas of policy appeasement and convergence. This may act as a stabilising factor in the region as the two powers acknowledge the significance of the other and the long‐term cost of direct confrontation on their respective interests. This potentially contributes to a ‘stable’ environment where thePacificIslandCountries are prevented from taking sides, which could potentially exacerbate tension and regional instability.
Immobilization of Enzymes on 2‐Hydroxyethyl Methacrylate and Glycidyl Methacrylate Copolymer Brushes
Authors: Ren Tanchen , Mao Zhengwei , Moya Sergio Enrique , Gao Changyou
Published: June 2014

The immobilization of enzymes is of paramount importance to maintain their activity and stability. In this study, surface‐initiated atom‐transfer radical polymerization was applied to prepare poly(2‐hydroxyethyl methacrylate)‐block‐poly(2‐hydroxyethyl methacrylate‐co‐glycidyl methacrylate) brushes on glass slides. The polymerization kinetics was followed by using a quartz crystal microbalance with dissipation monitoring and ellipsometry in terms of mass and thickness growth, respectively. The surface chemical compositions of the obtained polymer brushes were characterized by X‐ray photoelectron spectroscopy. Their mass, thickness, and enzyme‐immobilization ability could be easily tuned by the initiator reaction time, monomer ratio, and polymerization time. The antibacterial activity and stability of the immobilized lysozymes were studied by fluorescent staining and bacteria lysis assay, which revealed that the lysozymes on the copolymer brushes had good stability during storage at 4 °C for up to 30 days.
Facile Synthesis of Multifunctional Germanium Nanoparticles as a Carrier of Quercetin to Achieve Enhanced Biological Activity
Authors: Guo Yan‐Jie , Yang Fen , Zhang Lu , Pi Jiang , Cai Ji‐Ye , Yang Pei‐Hui
Published: June 2014

A simple method for preparing quercetin surface‐functionalized germanium nanoparticles (Qu‐GeNPs) with enhanced antioxidant and anticancer activity is reported. Spherical germanium nanoparticles (GeNPs) were capped by quercetin (Qu) with a mean particle size of approximately 33 nm and were characterized by TEM, AFM, UV‐visible absorption spectroscopy, FTIR, and XRD measurements. The in vitro drug release of Qu from the Qu‐GeNPs indicated that Qu could principally be distributed around tumor tissues rather than in the normal section and Qu‐GeNPs were internalized by MCF‐7 cells. Their biological activity test results indicated that these Qu‐GeNPs possessed stronger hydroxyl‐scavenging effects and proliferative inhibition effect on MCF‐7 cancer cells than quercetin, thus suggesting that the strategy to use GeNPs as a carrier of Qu could be an efficient way to achieve enhanced antioxidant and anticancer activity. In addition, Qu‐GeNPs possessed a high apoptotic induction effect in cancer cells, especially in high dosages, and could arrest MCF‐7 cells in the S phase.
Activation of Glycosyl Halides by Halogen Bonding
Authors: Castelli Riccardo , Schindler Severin , Walter Sebastian M. , Kniep Florian , Overkleeft Herman S. , Van der Marel Gijsbert A. , Huber Stefan M. , Codée Jeroen D. C.
Published: June 2014

Halogen bonding is the formation of a non‐covalent interaction between an electrophilic halogen substituent and a Lewis base, for instance, a halide. These kinds of relatively weak interactions have found applications in crystal engineering and initial applications in solution‐phase chemistry are starting to appear. We report on the exploration of bis(iodoimidazolium) compounds as halogen‐based Lewis acids in the activation of glycosyl halides. We show that these dicationic halogen‐bond donors can be used to activate glycosyl halides if the carbohydrate core is sufficiently reactive enough. Furthermore, we provide comparison experiments which indicate that the mode of activation is indeed based on halogen bonding. This represents the first glycosylation reaction mediated by a (carbon‐backbone‐based) halogen‐bond donor.
Probing the Shielding Properties of Aptameric Protective Groups
Authors: Bastian Andreas A. , Rodríguez‐Pulido Alberto , Gruszka Agnieszka , Gerasimov Jennifer Y. , Herrmann Andreas
Published: June 2014

Site‐specific derivatization of chemically equivalent functional groups has recently been facilitated by the introduction of high‐affinity aptamers as non‐covalent protective groups. More specifically, a series of RNA aptamers have proven to be highly efficient in enhancing the regioselectivity of reactions with the aminoglycoside antibiotic neomycin B, which carries several chemically indistinguishable amino and hydroxy groups. Since small‐molecule targets tend to exhibit multiple modes of binding with a single aptamer, the impact of secondary binding sites on the regioselectivity should be considered. To address this issue, we investigated a series of well‐characterized RNA aptamers that bind neomycin B and propose a mechanism that accounts for the regioselective outcome of these transformations. We further demonstrate that the regioselectivity induced by non‐covalent aptamer protective groups is determined by the number of binding sites, their affinity, and the mode of interaction with the guest molecule.
Absence of Preferential Unconscious Processing of Eye Contact in Adolescents With Autism Spectrum Disorder
Authors: Akechi Hironori , Stein Timo , Senju Atsushi , Kikuchi Yukiko , Tojo Yoshikuni , Osanai Hiroo , Hasegawa Toshikazu
Published: June 2014

Eye contact plays an essential role in social interaction. Atypical eye contact is a diagnostic and widely reported feature of autism spectrum disorder (ASD). Here, we determined whether altered unconscious visual processing of eye contact might underlie atypical eye contact in ASD. Using continuous flash suppression (CFS), we found that typically developing (TD) adolescents detected faces with a direct gaze faster than faces with an averted gaze, indicating enhanced unconscious processing of eye contact. Critically, adolescents with ASD did not show different durations of perceptual suppression for faces with direct and averted gaze, suggesting that preferential unconscious processing of eye contact is absent in this group. In contrast, in a non‐CFS control experiment, both adolescents with ASD and TD adolescents detected faces with a direct gaze faster than those with an averted gaze. Another CFS experiment confirmed that unconscious processing of non‐social stimuli is intact for adolescents with ASD. These results suggest that atypical processing of eye contact in individuals with ASD could be related to a weaker initial, unconscious registration of eye contact. Autism Res 2014, 7: 590–597. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.
How the Consideration of Positive Emotions Influences Persuasion: The Differential Effect of Pride Versus Joy
Authors: Karsh Noam , Eyal Tal
Published: June 2014

Although pride and joy are both positive emotions, we expected their consideration to affect persuasion differently because of the different perspectives (near vs. distant) and level of abstractness they involve, with pride being more abstract than joy. Therefore, we predicted that when the attitude object is construed at a high level rather than a low level, the consideration of pride is likely to promote more persuasion than the consideration of joy. In three studies, we found that the consideration of pride, when featured in the persuasion message (Studies 1a and 1b) or incidentally (Study 2), increased persuasion more than did the consideration of joy, when the persuasion object was temporally distant compared with temporally near (Studies 1a and 1b) or construed as a high‐level category compared with a more concrete individual (Study 2). These findings advance our understanding of the ways in which specific emotions may affect persuasion, beyond valence. Copyright © 2014 John Wiley & Sons, Ltd.
Binding of amifostine to human serum albumin: A biophysical study
Authors: Sun Yifu , Wu Han , Zhao Guoqing , Shi Ying
Published: June 2014

The aim of this present work is to investigate the interaction between amifostine and human serum albumin (HSA) in simulated physiological conditions by spectroscopic methods to reveal potential toxic effects of the drug. The results reflected that amifostine caused fluorescence quenching of HSA through a static quenching process, which was further confirmed by the electrochemical experiments. The binding constants at 290, 297 and 304 K were obtained as 2.53 × 105/M, 8.13 × 104/M and 3.59 × 104/M, respectively. There may be one binding site of amifostine on HSA. The thermodynamic parameters indicated that the interaction between amifostine and HSA was driven mainly by hydrogen bonding and electrostatic forces. Synchronous fluorescence spectra, circular dichroism and Fourier transform infrared spectroscopy results showed amifostine binding slightly changed the conformation of HSA with secondary structural content changes. Förster resonance energy transfer study revealed high possibility of energy transfer with amifostine‐Trp‐214 distance of 3.48 nm. The results of the present study may provide valuable information for studying the distribution, toxicological and pharmacological mechanisms of amifostine in vivo. Copyright © 2014 John Wiley & Sons, Ltd.
Evaluation of thermal injury to liver, pancreas and kidney during irreversible electroporation in an in vivo experimental model
Authors: Dunki-Jacobs E M , Philips P , Martin II R C G
Published: June 2014

Background

Irreversible electroporation (IRE) is a new technique for tumour cell ablation that is reported to involve non-thermal-based energy using high voltage at short microsecond pulse lengths. In vivo assessment of the thermal energy generated during IRE has not been performed. Thermal injury can be predicted using a critical temperature model. The aim of this study was to assess the potential for thermal injury during IRE in an in vivo porcine model.

Methods

In vivo continuous temperature assessments of 86 different IRE procedures were performed on porcine liver, pancreas, kidney and retroperitoneal tissue. Tissue temperature was measured continuously throughout IRE by means of two thermocouples placed at set distances (0·5 cm or less, and 1 cm) from the IRE probes within the treatment field. Thermal injury was defined as a tissue temperature of 54°C lasting at least 10 s. Tissue type, pulse length, probe exposure length, number of probes and retreatment were evaluated for associations with thermal injury. In addition, IRE ablation was performed with metal clips or metal stents within the ablation field to determine their effect on thermal injury.

Results

An increase in tissue temperature above the animals' baseline temperature (median 36·0°C) was generated during IRE in all tissues studied, with the greatest increase found at the thermocouple placed within 0·5 cm in all instances. On univariable and multivariable analysis, ablation in kidney tissue (maximum temperature 62·8°C), ablation with a pulse length setting of 100 µs (maximum 54·7°C), probe exposure of at least 3·0 cm (maximum 52·0°C) and ablation with metal within the ablation field (maximum 65·3°C) were all associated with a significant risk of thermal injury.

Conclusion

IRE can generate thermal energy, and even thermal injury, based on tissue type, probe exposure lengths, pulse lengths and proximity to metal. Awareness of probe placement regarding proximity to critical structures as well as probe exposure length and pulse length are necessary to ensure safety and prevent thermal injury. A probe exposure of 2·5 cm or less for liver IRE, and 1·5 cm or less for pancreas, with maximum pulse length of 90 µs will result in safe and non-thermal energy delivery with spacing of 1·5–2·3 cm between probe pairs.
Simultaneous determination of propofol and remifentanil in rat plasma by liquid chromatography–tandem mass spectrometry: application to preclinical pharmacokinetic drug–drug interaction analysis
Authors: El Hamd Mohamed A. , Wada Mitsuhiro , Ikeda Rie , Kawakami Shigeru , Kuroda Naotaka , Nakashima Kenichiro
Published: June 2014

Propofol (Pro) is an ultra‐short‐acting hypnotic agent used for general anesthesia that has no analgesic properties. Remifentanil (Rem) is an ultra‐short‐acting opioid administered concomitantly as an analgesic with Pro. To evaluate the pharmacokinetic interactions between Pro and Rem, we developed and validated a method combining high‐performance liquid chromatography with tandem mass spectrometry for simultaneous determination of Pro and Rem. The proposed method was successfully used to study the pharmacokinetic interactions of Pro and Rem coadministered to rats. Copyright © 2014 John Wiley & Sons, Ltd.
Excellence in Community College Student Affairs
Authors: Knight Ashley
Published: June 2014

Student success, accountability, and educational outcomes have been strongly emphasized in U.S. community colleges in recent years. For those individuals serving in community college student affairs, intentional commitment to standards and competencies in professional practice is essential in order to achieve institutional expectations and to meet increasing external demands. Student affairs leaders must provide structure and support to staff members along the continuum of experience from emerging student affairs professionals to mid‐level practitioners through senior‐level executives in order to identify potential leaders and to develop succession plans for the community colleges of tomorrow. This chapter explores the framework of excellence in the support, preparation, and ongoing professional development of community college student affairs professionals.
It Takes a Village: The Role of the Individual, Organization, and Profession in Preparing New Professionals
Authors: Lunceford Christina J.
Published: June 2014

Recruitment, socialization, and development of new professionals are critical to the ongoing success, continuous improvement, and advancement of community colleges. The varied experiences and preparation of student services professionals create a complexity of needs that provide challenges to effectively and efficiently help them transition and flourish in their colleges. This chapter includes examples of effective practice in educating, transitioning, and developing new student affairs professionals, and implications for individuals, colleges, and graduate preparation faculty.