bluuebunny/crossref_metadata_2025 huggingface dataset:
Oltmans Receives 2013 Yoram J. Kaufman Unselfish Cooperation in Research Award: Response
Authors: Oltmans Samuel J.
Published: August 2014

I am humbled to receive the Yoram J. Kaufman Unselfish Cooperation in Research Award. To be included in the distinguished company of the previous award recipients is an honor that is deeply gratifying.
Thompson Receives 2013 Early Career Hydrologic Science Award: Citation
Authors: Katul Gabriel
Published: August 2014

Sally Thompson grew up in Perth, where she was trained as an environmental engineer at the University of Western Australia. She graduated with honors in 2003 and worked for a few years as an environmental engineering consultant. Following the award of the Sir John Monash Fellowship in Australia, Sal accepted the admissions offer from the Nicholas School of the Environment at Duke University in 2006, completing her Ph.D. within 4 years and defending her dissertation in 2010. I was most fortunate to have Sal join me at Duke after an enthusiastic recommendation from Siva. Upon her arrival at Duke University, it was immediately clear to all that Sal is a special person with the remarkable skill of being able to identify the main aspects of a problem and throw at them the best that theory, experiment, and modeling tools offer.
Surface waves contribute to ice retreat in Beaufort Sea
Authors: Wendel JoAnna
Published: August 2014

Surface waves, created by blowing wind, play a role in energy and nutrient transport and also shape coasts through erosion. Because the Arctic Ocean is usually covered by ice year‐round, surface waves of the central Arctic Ocean have not been studied extensively.
California's ammonia emissions have been drastically underestimated
Authors: Schultz Colin
Published: August 2014

In California, Los Angeles and the Central Valley often have atmospheric concentrations of particulate matter that exceed the U.S. Environmental Protection Agency's health guidelines. In the air, chemical reactions between ammonia, nitrogen oxides, and sulfur oxides can create inorganic aerosols like ammonium nitrate and ammonium sulfate. With their small particle sizes, these compounds can be dangerous to breathe, particularly for those with respiratory problems.
Simulating the Earth's radiation belts: Internal acceleration and continuous losses to the magnetopause
Authors: Glauert Sarah A. , Horne Richard B. , Meredith Nigel P.
Published: August 2014

In the Earth's radiation belts the flux of relativistic electrons is highly variable, sometimes changing by orders of magnitude within a few hours. Since energetic electrons can damage satellites it is important to understand the processes driving these changes and, ultimately, to develop forecasts of the energetic electron population. One approach is to use three‐dimensional diffusion models, based on a Fokker‐Planck equation. Here we describe a model where the phase‐space density is set to zero at the outer L∗ boundary, simulating losses to the magnetopause, using recently published chorus diffusion coefficients for 1.5≤L∗≤10. The value of the phase‐space density on the minimum‐energy boundary is determined from a recently published, solar wind‐dependent, statistical model. Our simulations show that an outer radiation belt can be created by local acceleration of electrons from a very soft energy spectrum without the need for a source of electrons from inward radial transport. The location in L∗ of the peaks in flux for these steady state simulations is energy dependent and moves earthward with increasing energy. Comparisons between the model and data from the CRRES spacecraft are shown; flux dropouts are reproduced in the model by the increased outward radial diffusion that occurs during storms. Including the inward movement of the magnetopause in the model has little additional effect on the results. Finally, the location of the low‐energy boundary is shown to be important for accurate modeling of observations.
Three‐dimensional stochastic modeling of radiation belts in adiabatic invariant coordinates
Authors: Zheng Liheng , Chan Anthony A. , Albert Jay M. , Elkington Scot R. , Koller Josef , Horne Richard B. , Glauert Sarah A. , Meredith Nigel P.
Published: August 2014

A 3‐D model for solving the radiation belt diffusion equation in adiabatic invariant coordinates has been developed and tested. The model, named Radbelt Electron Model, obtains a probabilistic solution by solving a set of Itô stochastic differential equations that are mathematically equivalent to the diffusion equation. This method is capable of solving diffusion equations with a full 3‐D diffusion tensor, including the radial‐local cross diffusion components. The correct form of the boundary condition at equatorial pitch angle α0=90° is also derived. The model is applied to a simulation of the October 2002 storm event. At α0 near 90°, our results are quantitatively consistent with GPS observations of phase space density (PSD) increases, suggesting dominance of radial diffusion; at smaller α0, the observed PSD increases are overestimated by the model, possibly due to the α0‐independent radial diffusion coefficients, or to insufficient electron loss in the model, or both. Statistical analysis of the stochastic processes provides further insights into the diffusion processes, showing distinctive electron source distributions with and without local acceleration.
Seasonal salinity stratifications in the near‐surface layer from Aquarius, Argo, and an ocean model: Focusing on the tropical Atlantic/Indian Oceans
Authors: Moon Jae‐Hong , Song Y. Tony
Published: August 2014

A newly available sea surface salinity (SSS) measurement from Aquarius/SAC‐D satellite reveals strong seasonal variability in the tropical Atlantic and Indian Oceans. The seasonal SSS variability at skin layer differs/agrees regionally in their amplitude from/with Argo‐measured salinity at 5 m depth and model salinity at the top layer, indicating various characteristics of near‐surface salinity stratifications. By comparing the three different salinity products, we have examined the near‐surface salinity stratifications with emphasis on the dynamical processes that differ from one region to another. Our analysis shows that for the western part of tropical Atlantic and southern tropical Indian, a large amount of river runoff and/or surface freshwater significantly stratifies the surface layer above 5 m depth, resulting in the differences among the Aquarius, Argo, and model. Differently for the southern Arabian Sea, the surface water can be mixed down to the depth of 5 m due to seasonally reversing currents driven by monsoons, resulting in an agreement among the data sets. The comparison suggests that dynamical differences can lead to different vertical salinity stratifications locally, which explain the differences between the Aquarius observations in the first cm of the sea surface, the Argo measurements at the 5 m depth, and model's representation of the surface‐layer averaged salinity.
Towards van der Waals Epitaxial Growth of GaAs on Si using a Graphene Buffer Layer
Authors: Alaskar Yazeed , Arafin Shamsul , Wickramaratne Darshana , Zurbuchen Mark A. , He Liang , McKay Jeff , Lin Qiyin , Goorsky Mark S. , Lake Roger K. , Wang Kang L.
Published: August 2014

Van der Waals growth of GaAs on silicon using a two‐dimensional layered material, graphene, as a lattice mismatch/thermal expansion coefficient mismatch relieving buffer layer is presented. Two‐dimensional growth of GaAs thin films on graphene is a potential route towards heteroepitaxial integration of GaAs on silicon in the developing field of silicon photonics. Hetero‐layered GaAs is deposited by molecular beam epitaxy on graphene/silicon at growth temperatures ranging from 350 °C to 600 °C under a constant arsenic flux. Samples are characterized by plan‐view scanning electron microscopy, atomic force microscopy, Raman microscopy, and X‐ray diffraction. The low energy of the graphene surface and the GaAs/graphene interface is overcome through an optimized growth technique to obtain an atomically smooth low­ temperature GaAs nucleation layer. However, the low adsorption and migration energies of gallium and arsenic atoms on graphene result in cluster‐growth mode during crystallization of GaAs films at an elevated temperature. In this paper, we present the first example of an ultrasmooth morphology for GaAs films with a strong (111) oriented fiber‐texture on graphene/silicon using quasi van der Waals epitaxy, making it a remarkable step towards an eventual demonstration of the epitaxial growth of GaAs by this approach for heterogeneous integration.
Polymer Fiber Probes Enable Optical Control of Spinal Cord and Muscle Function In Vivo
Authors: Lu Chi , Froriep Ulrich P. , Koppes Ryan A. , Canales Andres , Caggiano Vittorio , Selvidge Jennifer , Bizzi Emilio , Anikeeva Polina
Published: August 2014

Restoration of motor and sensory functions in paralyzed patients requires the development of tools for simultaneous recording and stimulation of neural activity in the spinal cord. In addition to its complex neurophysiology, the spinal cord presents technical challenges stemming from its flexible fibrous structure and repeated elastic deformation during normal motion. To address these engineering constraints, we developed highly flexible fiber probes, consisting entirely of polymers, for combined optical stimulation and recording of neural activity. The fabricated fiber probes exhibit low‐loss light transmission even under repeated extreme bending deformations. Using our fiber probes, we demonstrate simultaneous recording and optogenetic stimulation of neural activity in the spinal cord of transgenic mice expressing the light sensitive protein channelrhodopsin 2 (ChR2). Furthermore, optical stimulation of the spinal cord with the polymer fiber probes induces on‐demand limb movements that correlate with electromyographical (EMG) activity.
Nanoscale Resistive Switching in Amorphous Perovskite Oxide (a‐SrTiO3) Memristors
Authors: Nili Hussein , Walia Sumeet , Balendhran Sivacarendran , Strukov Dmitri B. , Bhaskaran Madhu , Sriram Sharath
Published: August 2014

Memristive devices are the precursors to high density nanoscale memories and the building blocks for neuromorphic computing. In this work, a unique room temperature synthesized perovskite oxide (amorphous SrTiO3: a‐STO) thin film platform with engineered oxygen deficiencies is shown to realize high performance and scalable metal‐oxide‐metal (MIM) memristive arrays demonstrating excellent uniformity of the key resistive switching parameters. a‐STO memristors exhibit nonvolatile bipolar resistive switching with significantly high (103–104) switching ratios, good endurance (>106I–V sweep cycles), and retention with less than 1% change in resistance over repeated 105 s long READ cycles. Nano‐contact studies utilizing in situ electrical nanoindentation technique reveal nanoionics driven switching processes that rely on isolatedly controllable nano‐switches uniformly distributed over the device area. Furthermore, in situ electrical nanoindentation studies on ultrathin a‐STO/metal stacks highlight the impact of mechanical stress on the modulation of non‐linear ionic transport mechanisms in perovskite oxides while confirming the ultimate scalability of these devices. These results highlight the promise of amorphous perovskite memristors for high performance CMOS/CMOL compatible memristive systems.
Lending Triarylphosphine Oxide to Phenanthroline: a Facile Approach to High‐Performance Organic Small‐Molecule Cathode Interfacial Material for Organic Photovoltaics utilizing Air‐Stable Cathodes
Authors: Tan Wan‐Yi , Wang Rui , Li Min , Liu Gang , Chen Ping , Li Xin‐Chen , Lu Shun‐Mian , Zhu Hugh Lu , Peng Qi‐Ming , Zhu Xu‐Hui , Chen Wei , Choy Wallace C. H. , Li Feng , Peng Junbiao , Cao Yong
Published: August 2014

Cathode interfacial material (CIM) is critical to improving the power conversion efficiency (PCE) and long‐term stability of an organic photovoltaic cell that utilizes a high work function cathode. In this contribution, a novel CIM is reported through an effective and yet simple combination of triarylphosphine oxide with a 1,10‐phenanthrolinyl unit. The resulting CIM possesses easy synthesis and purification, a high T
g of 116 °C and attractive electron‐transport properties. The characterization of photovoltaic devices involving Ag or Al cathodes shows that this thermally deposited interlayer can considerably improve the PCE, due largely to a simultaneous increase in V
oc and FF relative to the reference devices without a CIM. Notably, a PCE of 7.51% is obtained for the CIM/Ag device utilizing the active layer PTB7:PC71BM, which far exceeds that of the reference Ag device and compares well to that of the Ca/Al device. The PCE is further increased to 8.56% for the CIM/Al device (with J
sc = 16.81 mA cm−2, V
oc = 0.75 V, FF = 0.68). Ultraviolet photoemission spectroscopy studies reveal that this promising CIM can significantly lower the work function of the Ag metal as well as ITO and HOPG, and facilitate electron extraction in OPV devices.
Driving Spin and Charge in Quantum Wells by Surface Acoustic Waves
Authors: Wanner Johannes , Gorini Cosimo , Schwab Peter , Eckern Ulrich
Published: August 2014

Recent experiments have shown the potential of surface acoustic waves as a mean for transporting charge and spin in quantum wells. In particular, they have proven highly effective for the coherent transport of spin‐polarized wave packets, suggesting their potential in spintronics applications. Motivated by these experimental observations, the spin and charge dynamics in a quantum well under surface acoustic waves is theoretically studied. It is shown that the dynamics acquires a simple and transparent form in a reference frame co‐moving with the surface acoustic wave. The results, e.g., the calculated spin relaxation and precession lengths, are in excellent agreement with recent experimental observations.
On the Magnitude of the Geographic Distance Effect on Primary Agricultural and Processed Food Trade
Authors: Ghazalian Pascal L.
Published: August 2014

The empirical trade literature regularly emphasizes the essential role of the geographic distance in determining the levels and patterns of international trade. This paper examines the diversities in the magnitude of the geographic distance effects on primary agricultural trade and on processed food trade between OECD countries. The empirical results from different specifications of the gravity model reveal the existence of significant variations in the magnitude of the distance effects on primary agricultural trade and on processed food trade over time and through economic, geo‐economic, and socio‐economic characteristics of the exporting and importing countries. These findings imply that disregarding the variations through the distance effect by relying on overall estimates would adversely affect the design of trade policies, and would limit the understanding of trade patterns.
Are Export Restrictions an Effective Instrument to Insulate Domestic Prices Against Skyrocketing World Market Prices? The Wheat Export Ban in Serbia
Authors: Djuric Ivan , Götz Linde , Glauben Thomas
Published: August 2014

This article analyzes how the market interventions of the Serbian government, among them an export ban, affected the domestic wheat market during the global commodity price peak in 2007–2008. We choose a flexible Markov‐switching error‐correction model as the framework for our price transmission analysis. The results show that the price transmission regime was not changed by the export ban. Thus, the export controls were not successful in dampening the domestic wheat price level. We make evident that the expected price decreasing effects of the export ban were offset by inconsistent additional policy measures and their faulty sequencing. Further, the governmental market interventions had even long‐lasting destabilizing market effects. Market instability was increased particularly after the cancellation of the export ban.
Longitudinal hormonal evaluation in a patient with disorder of sexual development, 46,XY karyotype and one NR5A1 mutation
Authors: Pedace Lucia , Laino Luigi , Preziosi Nicoletta , Valentini Maria Stella , Scommegna Salvatore , Rapone Anna Maria , Guarino Nino , Boscherini Brunetto , De Bernardo Carmelilia , Marrocco Giacinto , Majore Silvia , Grammatico Paola
Published: August 2014

Steroidogenic factor 1 (encoded by the NR5A1 gene) is a critical regulator of reproduction, controlling transcription of key genes involved in sexual dimorphism. To date, NR5A1 variants have been found in individuals with a 46,XY karyotype and gonadal dysgenesis, as well as with a wide spectrum of genital anomalies and, in some patients, with adrenal insufficiency. We describe evolution of gonadal function, from the neonatal period to puberty, in a patient with a 46,XY karyotype, a disorder of sexual development, and a mutation (c.691_699dupCTGCAGCTG) in the NR5A1 gene. The patient, ascertained at birth due to ambiguous genitalia, showed normal values of plasma testosterone in the late neonatal period. Evaluation of the hormonal profile over time indicated severe tubular testicular hypofunction suggestive for a 46,XY disorder of gonadal development. A comprehensive review of published reports of 46,XY and disordered sexual development related to the NR5A1 gene confirmed the clinical and hormonal variability in patients with NR5A1 mutations. Analysis of multiple data allowed us to define the most common features associated with NR5A1 mutations. We further confirmed the indication to perform NR5A1 screening in patients with 46,XY karyotype and disordered sexual development even when Müllerian structures appear to be absent and plasma testosterone levels are within the normal range for age. © 2014 Wiley Periodicals, Inc.
Plasticity and constraint in response to early‐life stressors among late/final jomon period foragers from Japan: Evidence for life history trade‐offs from incremental microstructures of enamel
Authors: Temple Daniel H.
Published: August 2014

This study evaluates two hypotheses that address how Late/Final Jomon period people responded to early‐life stress using linear enamel hypoplasia (LEH) and incremental microstructures of enamel. The first hypothesis predicts that Jomon people who experienced early‐life stressors had greater physiological competence in responding to future stress events (predictive adaptive response). The second hypothesis predicts that Jomon people traded‐off in future growth and maintenance when early investment in growth and survival was required (plasticity/constraint). High resolution tooth impressions were collected from intact, anterior teeth and studied under an engineer's measuring microscope. LEH were identified based on accentuated perikymata and depressions in the enamel surface profile. Age of formation for each LEH was estimated by summing counts of perikymata and constants associated with crown initiation and cuspal enamel formation times. The relationship between age‐at‐first‐defect formation, number of LEH, periodicity between LEH, and mortality was evaluated using multiple regression and hazards analysis. A significant, positive relationship was found between age‐at‐death relative to age‐at‐first‐defect formation and a significant, negative relationship was found between number of LEH relative to age‐at‐first‐defect formation. Individuals with earlier forming defects were at a significantly greater risk of forming defects at later stages of development and dying at younger ages. These results suggest that Late/Final Jomon period foragers responded to early‐life stressors in a manner consistent with the plasticity/constraint hypothesis of human life history. Late/Final Jomon period individuals were able to survive early‐life stressors, but this investment weakened responses to future stress events and exacerbated mortality schedules. Am J Phys Anthropol 155:537–545, 2014. © 2014 Wiley Periodicals, Inc.
Phenotype of matrin‐3–related distal myopathy in 16 German patients
Authors: Müller Tobias J. , Kraya Torsten , Stoltenburg‐Didinger Gisela , Hanisch Frank , Kornhuber Malte , Stoevesandt Dietrich , Senderek Jan , Weis Joachim , Baum Petra , Deschauer Marcus , Zierz Stephan
Published: August 2014

Objective

To characterize the phenotype of patients with distal myopathy with vocal cord and pharyngeal weakness due to the p.S85C mutation in the matrin‐3 gene (MATR3, Mendelian Inheritance in Man 164015). Recently, it has been suggested that patients with this mutation may suffer from familial amyotrophic lateral sclerosis.

Methods

Sixteen patients from 6 families with late onset distal myopathy associated with the p.S85C MATR3 mutation were characterized.

Results

Patients had a predominantly distal muscle weakness, most severely affecting ankle and wrist dorsiflexion. Relevant proximal and axial weakness was found in 6 and respiratory impairment in 5 patients. Dysphagia was diagnosed in 6 and mild voice abnormalities were found in 7 patients. However, laryngoscopy revealed normal vocal cord function. Creatine kinase was normal or mildly elevated. Electromyographically, spontaneous activity was found in 10 of 14 patients and complex repetitive discharges in 9 of 14 patients. Magnetic resonance imaging revealed severe fatty degeneration of distal and upper posterior leg and of paraspinal muscles. Histopathology ranged from mild myopathic to severe dystrophic changes including vacuoles. Absence of sarcomeres in the perinuclear region and abnormal invaginations of nuclei were found ultrastructurally. Haplotype analysis showed a common disease‐specific haplotype of the 6 families and suggested that these families form a separate cluster.

Interpretation

In contrast to the 2 previously reported families, MATR3‐related distal myopathy might be associated with relevant axial, proximal, and respiratory muscle weakness but without vocal cord palsy. There were no clinical, electrophysiological, or histopathological signs of lower motor neuron involvement. Ann Neurol 2014;76:669–680
Synthese von katalytisch stabilen und sinterbeständigen Palladium‐Nanopartikeln auf der inneren Oberfläche von Kohlenstoff‐Nanoröhren
Authors: Liu Hongyang , Zhang Liyun , Wang Ning , Su Dang Sheng
Published: August 2014

Die effiziente Synthese von Kohlenstoff‐Nanoröhren (CNTs) mit eingebetteten Metall‐Nanopartikeln ist ein herausfordernder Prozess. Wir stellen eine templatgesteuerte Prozedur für die Herstellung von CNTs vor, auf deren Innenwänden homogen strukturierte Pd‐Nanopartikel eingebettet sind. Dieses neuartige Nanokomposit zeigt eine den herkömmlichen Pd/CNT‐Katalysatoren deutlich überlegene Sinterbeständigkeit. Es ist überdies in hohem Maße wiederverwendbar, was in einer Suzuki‐Kupplung in flüssiger Phase getestet wurde. Die Syntheseroute könnte als allgemeiner Ansatz für die Herstellung unterschiedlicher Metall‐Nanopartikel auf CNT‐Trägern dienen.
Re‐Appearance of Cooperativity in Ultra‐Small Spin‐Crossover [Fe(pz){Ni(CN)4}] Nanoparticles
Authors: Peng Haonan , Tricard Simon , Félix Gautier , Molnár Gábor , Nicolazzi William , Salmon Lionel , Bousseksou Azzedine
Published: August 2014

A reverse nanoemulsion technique was used for the elaboration of [Fe(pz){Ni(CN)4}] nanoparticles. Low‐temperature micellar exchange made it possible to elaborate ultra‐small nanoparticles with sizes down to 2 nm. When decreasing the size of the particles from 110 to 12 nm the spin transition shifts to lower temperatures, becomes gradual, and the hysteresis shrinks. On the other hand, a re‐opening of the hysteresis was observed for smaller (2 nm) particles. A detailed 57Fe Mössbauer spectroscopy analysis was used to correlate this unusual phenomenon to the modification of the stiffness of the nanoparticles thanks to the determination of their Debye temperature.
Flavin Redox Bifurcation as a Mechanism for Controlling the Direction of Electron Flow during Extracellular Electron Transfer
Authors: Okamoto Akihiro , Hashimoto Kazuhito , Nealson Kenneth H.
Published: August 2014

The iron‐reducing bacterium Shewanella oneidensis MR‐1 has a dual directional electronic conduit involving 40 heme redox centers in flavin‐binding outer‐membrane c‐type cytochromes (OM c‐Cyts). While the mechanism for electron export from the OM c‐Cyts to an anode is well understood, how the redox centers in OM c‐Cyts take electrons from a cathode has not been elucidated at the molecular level. Electrochemical analysis of live cells during switching from anodic to cathodic conditions showed that altering the direction of electron flow does not require gene expression or protein synthesis, but simply redox potential shift about 300 mV for a flavin cofactor interacting with the OM c‐Cyts. That is, the redox bifurcation of the riboflavin cofactor in OM c‐Cyts switches the direction of electron conduction in the biological conduit at the cell–electrode interface to drive bacterial metabolism as either anode or cathode catalysts.
Formation of Nanoparticles and Nanostructures—An Industrial Perspective on CaCO3, Cement, and Polymers
Authors: Rieger Jens , Kellermeier Matthias , Nicoleau Luc
Published: August 2014

Nanotechnology enables the design of materials with outstanding performance. A key element of nanotechnology is the ability to manipulate and control matter on the nanoscale to achieve a certain desired set of specific properties. Here, we discuss recent insight into the formation mechanisms of inorganic nanoparticles during precipitation reactions. We focus on calcium carbonate, and describe the various transient stages potentially occurring on the way from the dissolved constituent ions to finally stable macrocrystals—including solute ion clusters, dense liquid phases, amorphous intermediates, and nanoparticles. The role of polymers in nucleating, templating, stabilizing, and/or preventing these structures is outlined. As a specific example for applied nanotechnology, the properties of cement are shown to be determined by the formation and interlocking of calcium‐silicate‐hydrate nanoplatelets. The aggregation of these platelets into mesoscale architectures can be controlled with polymers.
Aldehyde‐Assisted Ruthenium(II)‐Catalyzed CH Oxygenations
Authors: Yang Fanzhi , Rauch Karsten , Kettelhoit Katharina , Ackermann Lutz
Published: August 2014

Versatile ruthenium(II) complexes allow for site‐selective CH oxygenations with weakly‐coordinating aldehydes. The challenging CH functionalizations proceed with high chemoselectivity by rate‐determining CH metalation. The new method features an ample substrate scope, which sets the stage for the step‐economical preparation of various bioactive heterocycles.
Palladium Nanoparticles Embedded in the Inner Surfaces of Carbon Nanotubes: Synthesis, Catalytic Activity, and Sinter Resistance
Authors: Liu Hongyang , Zhang Liyun , Wang Ning , Su Dang Sheng
Published: August 2014

The highly efficient preparation of metal nanoparticles embedded in a carbon nanotube remains a considerable challenge. Herein, we report a simple and template‐based procedure for the fabrication of carbon nanotubes with Pd nanoparticles uniformly embedded in the inner carbon surfaces. In addition to the novel structure, the sinter‐resistance of the as‐prepared Pd/C nanocomposite was much better than that of the traditional carbon‐nanotube‐supported Pd catalysts. The as‐prepared Pd/C nanocomposite has a high recyclability in a liquid‐phase Suzuki coupling reaction. This strategy may be extended as a general approach to prepare metal nanoparticles supported on carbon‐nanotubes.
Silver‐releasing and antibacterial activities of polyphenol‐based polyurethanes
Authors: Chen Jia , Peng Ying , Zheng Zhen , Sun Peiyu , Wang Xinling
Published: August 2014

Inspired by mussel adhesive proteins, catechol functional groups play an important role in the ability of the mussel to adhere to organic and inorganic surfaces. A novel functional polyurethane (PU) based on hydrolysable tannins that contain a number of catechol groups was successfully synthesized and characterized. These catechol groups were used as a reducer for Ag (I) to form Ag (0), and to prepare polyurethane/silver nanoparticles composites. These kinds of polyurethane containing Ag nanoparticles showed obvious inhibition of bacterial growth because of the conjunct actions of the well‐known antibacterial property of silver and the antifouling property of PEG. It is possible for these materials to be applied widely into antibacterial adhesive coatings for surface modification due to their low cost and the material‐independent adhesive property of catechol groups in tannins. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41349.
Genome engineering and gene expression control for bacterial strain development
Authors: Song Chan Woo , Lee Joungmin , Lee Sang Yup
Published: August 2014

In recent years, a number of techniques and tools have been developed for genome engineering and gene expression control to achieve desired phenotypes of various bacteria. Here we review and discuss the recent advances in bacterial genome manipulation and gene expression control techniques, and their actual uses with accompanying examples. Genome engineering has been commonly performed based on homologous recombination. During such genome manipulation, the counterselection systems employing SacB or nucleases have mainly been used for the efficient selection of desired engineered strains. The recombineering technology enables simple and more rapid manipulation of the bacterial genome. The group II intron‐mediated genome engineering technology is another option for some bacteria that are difficult to be engineered by homologous recombination. Due to the increasing demands on high‐throughput screening of bacterial strains having the desired phenotypes, several multiplex genome engineering techniques have recently been developed and validated in some bacteria. Another approach to achieve desired bacterial phenotypes is the repression of target gene expression without the modification of genome sequences. This can be performed by expressing antisense RNA, small regulatory RNA, or CRISPR RNA to repress target gene expression at the transcriptional or translational level. All of these techniques allow efficient and rapid development and screening of bacterial strains having desired phenotypes, and more advanced techniques are expected to be seen.
Photon up‐conversion increases biomass yield in Chlorella vulgaris
Authors: Menon Kavya R. , Jose Steffi , Suraishkumar Gadi K.
Published: August 2014

Photon up‐conversion, a process whereby lower energy radiations are converted to higher energy levels via the use of appropriate phosphor systems, was employed as a novel strategy for improving microalgal growth and lipid productivity. Photon up‐conversion enables the utilization of regions of the solar spectrum, beyond the typical photosynthetically active radiation, that are usually wasted or are damaging to the algae. The effects of up‐conversion of red light by two distinct sets of up‐conversion phosphors were studied in the model microalgae Chlorella vulgaris. Up‐conversion by set 1 phosphors led to a 2.85 fold increase in biomass concentration and a 3.2 fold increase in specific growth rate of the microalgae. While up‐conversion by set 2 phosphors resulted in a 30% increase in biomass and 12% increase in specific intracellular neutral lipid, while the specific growth rates were comparable to that of the control. Furthermore, up‐conversion resulted in higher levels of specific intracellular reactive oxygen species in C. vulgaris. Up‐conversion of red light (654 nm) was shown to improve biomass yields in C. vulgaris. In principle, up‐conversion can be used to increase the utilization range of the electromagnetic spectrum for improved cultivation of photosynthetic systems such as plants, algae, and microalgae.
3D morphometric analysis of the arterial switch operation using in vivo MRI data
Authors: Ntsinjana Hopewell N. , Capelli Claudio , Biglino Giovanni , Cook Andrew C. , Tann Oliver , Derrick Graham , Taylor Andrew M. , Schievano Silvia
Published: August 2014

The arterial switch operation (ASO) is widely used nowadays as the surgical strategy of choice to repair transposition of the great arteries (TGA). Residual morphological and geometrical abnormalities of the aorta, pulmonary arteries and coronary arteries, however, have not been fully studied in a three‐dimensional (3D) domain. These morphometric complications might have implications on long‐term outcomes of ASO patients, hence the need to explore them in detail and study them with reference to healthy controls of comparable age and body surface area. These anatomical characteristics were examined using 3D patient‐specific anatomical models reconstructed from cardiovascular magnetic resonance (CMR) images of 20 ASO patients (mean age 14.4 ± 2.4 years, 16 males and 4 females) compared with healthy controls (mean age 15.2 ± 2.0 years, 17 males and 3 females). It was found that the aorta, pulmonary arteries and re‐implanted coronary arteries of ASO patients were significantly different morphologically and geometrically to those of healthy controls. In particular, the aortic root was dilated, with abnormal 3D angulation and additional acute angulation of the curvature of the aortic arch in the ASO group compared with controls. This could theoretically impinge on aortic flow profiles and physiological stresses, which can act as a primer for the development of early atherosclerotic disease in the ASO population. Clin. Anat. 27:1212–1222, 2014. © 2014 Wiley Periodicals, Inc.
Identification of EGFR expression status association with metastatic lymph node density (ND) by expression microarray analysis of advanced gastric cancer
Authors: Ema Akira , Waraya Mina , Yamashita Keishi , Kokubo Kenichi , Kobayashi Hirosuke , Hoshi Keika , Shinkai Yoshiko , Kawamata Hiroshi , Nakamura Kazunori , Nishimiya Hiroshi , Katada Natsuya , Watanabe Masahiko
Published: August 2014

Metastatic lymph node density (ND) has been reproducibly proven to be a prognostic factor in gastric cancer. The molecular mechanisms that underlie this aggressiveness are underexplored. Here, we aimed to identify molecules associated with this unique phenotype. Tumor specimens from patients with stage III gastric cancer with high or low ND (n = 4 for both) were compared at the mRNA level using Affymetrix microarray (harboring 54,675 genes). The expression data were prioritized, and genes that correlated with ND were selected. Ultimately, the EGFR was validated as such a candidate molecule in patients with primary advanced gastric cancer who underwent standard treatment (n = 167). Expression data of the microarray were prioritized based on gene expression ratio and frequency of gene expression. The first priority genes to be selected were genes that are known to be amplified in cancer, which included NKX2.1, CHST9, CTNND2, SLC25A27, FGFR2, EGFR, and PTGER1. Of these genes, the EGFR gene was of particular interest. EGFR expression in primary gastric cancer was examined using immunohistochemistry (IHC). The Student's t‐test elucidated a significant difference in EGFR expression between IHC 2+/3+ and IHC 1+ according to ND (P = 0.0035). The Chi‐square test also indicated a significant difference between high and low levels of EGFR immunohistochemical staining (IHC2+/3+ and IHC1+, respectively) and ND status (P = 0.0023). According to the least squares method, as ND increased, the risk that EGFR staining levels changed from IHC 1+ to IHC 2+ also increased. In this study, we determined that high EGFR expression may underlie the aggressive mechanism of advanced gastric cancer with high ND.
Probing Ambiguous Base‐Pairs by Genetic Transformation with XNA Templates
Authors: Pezo Valérie , Schepers Guy , Lambertucci Catia , Marlière Philippe , Herdewijn Piet
Published: August 2014

The templating potential of anhydrohexitol oligonucleotides bearing ambiguous bases was studied in vivo, by using a selection screen for mosaic heteroduplex plasmids in Escherichia coli. 1,5‐Anhydro‐2,3‐dideoxy‐2‐(5‐nitroindazol‐1‐yl)‐D‐arabino‐hexitol showed the greatest ambiguity among the three nucleosides tested. At most two successive ambiguous bases could be tolerated on hexitol templates read in bacterial cells. Hexitol nucleosides bearing simplified heterocycles thus stand as promising monomers for generating random DNA sequences in vivo from defined synthetic oligonucleotides.
Substrate Requirements for Palladium–Aluminium Triflate Co‐catalysed Hydromethoxycarbonylation Reactions of Alkynes Bearing Oxygen Atoms
Authors: Makume Boitumelo F. , Bredenkamp Tyler , Williams D. Bradley G.
Published: August 2014

The palladium diacetate–aluminium triflate combination is an effective catalyst for the hydromethoxycarbonylation reaction of isolated alkenes and alkynes. However, its application in the hydromethoxycarbonylation of oxygen atom‐bearing alkynes is non‐trivial: the position relative to the alkyne (e.g., allylic, homoallylic) and nature of the oxygen atom determine the success of the transformation. We detail the minimum structural requirements for a successful outcome with ether‐containing alkyne substrates and hydroxyl‐containing analogues. In general, the oxygen atom has a detrimental effect on the outcome of the hydromethoxycarbonylation reaction, which can be overcome in many instances. The presence of the oxygen atom(s) causes decreases in the rate of the reaction compared to aliphatic alkynes and the closer the oxygen atom is to the triple bond, the more pronounced the effect. The chemistry is demonstrated on complex substrates derived from 5 and 6‐carbon sugars in optimised reactions.
Halogenotrinitromethanes: A Combined Study in the Crystalline and Gaseous Phase and Using Quantum Chemical Methods
Authors: Klapötke Thomas M. , Krumm Burkhard , Moll Richard , Rest Sebastian F. , Vishnevskiy Yury V. , Reuter Christian , Stammler Hans‐Georg , Mitzel Norbert W.
Published: August 2014

The halogenotrinitromethanes FC(NO2)3(1), BrC(NO2)3(2), and IC(NO2)3(3) were synthesized and fully characterized. The molecular structures of1–3were determined in the crystalline state by X‐ray diffraction, and gas‐phase structures of1and2were determined by electron diffraction. The HalC bond lengths in F, Cl, and BrC(NO2)3in the crystalline state are similar to those in the gas phase. The obtained experimental data are interpreted in terms of Natural Bond Orbitals (NBO), Atoms in Molecules (AIM), and Interacting Quantum Atoms (IQA) theories. All halogenotrinitromethanes show various intra‐ and intermolecular non‐bonded interactions. Intramolecular N⋅⋅⋅O and Hal⋅⋅⋅O (Hal=F (1), Br (2), I (3)) interactions, both competitors in terms of the orientation of the nitro groups by rotation about the CN bonds, lead to a propeller‐type twisting of these groups favoring the mentioned interactions. The origin of the unusually short HalC bonds is discussed in detail. The results of this study are compared to the molecular structure of ClC(NO2)3and the respective interactions therein.
Stereoselective Synthesis of Aryl Cyclopentene Scaffolds by Heck–Matsuda Desymmetrization of 3‐Cyclopentenol
Authors: Angnes Ricardo A. , Oliveira Juliana M. , Oliveira Caio C. , Martins Nelson C. , Correia Carlos Roque D.
Published: August 2014

A new enantioselective Heck–Matsuda desymmetrization reaction was accomplished by using 3‐cyclopentenol to produce chiral five‐membered 4‐aryl cyclopentenol scaffolds in good yields and high ee’s, together with some 3‐aryl‐cyclopentanones as minor products. Mechanistically, the hydroxyl group of 3‐cyclopentenol acts as a directing group and is responsible for the cis‐ arrangement in the formation of the 4‐aryl‐cyclopentenols.
Effects of Atrioventricular Nodal Ablation on Permanent Atrial Fibrillation Patients With Cardiac Resynchronization Therapy: A Systematic Review and Meta‐analysis
Authors: Yin Jie , Hu Hesheng , Wang Ye , Xue Mei , Li Xiaolu , Cheng Wenjuan , Li Xinran , Yan Suhua
Published: August 2014

Cardiac resynchronization therapy (CRT) is a well‐established therapy for patients with heart failure (HF) and wide QRS configuration, especially for those in sinus rhythm. However, for those with permanent AF, atrioventricular nodal (AVN) ablation use remains under debate. Our objective was to evaluate clinical outcomes and mortality of AVN ablation in HF patients with permanent AF receiving CRT. Electronic publication database and reference lists through October 1, 2013 were searched. Observational cohort studies comparing CRT patients with AF who received either AVN ablation or medical therapy were selected. Outcomes included mortality, CRT nonresponse, changes in left ventricular remodeling, and functional outcomes, such as New York Heart Association (NYHA) functional class, quality of life, and 6‐minute hall walk distance. Of 1641 reports identified, 13 studies with 1256 patients were included. Among patients with permanent AF and insufficient biventricular pacing (<90%), those who had undergone AVN ablation compared to those who did not had numerically lower all‐cause mortality (risk ratio [RR]: 0.63, 95% confidence interval [CI]: 0.42 to 0.96, P = 0.03) and significantly lower nonresponse to CRT (RR: 0.41, 95% CI: 0.31 to 0.54, P < 0.00001). Furthermore, AVN ablation was not associated with additional improvements on left ventricular ejection fraction, NYHA functional class, 6‐minute hall walking distance, and quality of life. In patients with permanent AF undergoing CRT, AVN ablation tended to reduce mortality potentially and improved clinical response when it was applied to patients with inadequate biventricular pacing (<90%). Randomized controlled trials are needed to further address the efficacy of AVN ablation among this population.
5‐(Piperidin‐4‐yl)‐3‐Hydroxypyrazole: A Novel Scaffold for Probing the Orthosteric γ‐Aminobutyric Acid Type A Receptor Binding Site
Authors: Krall Jacob , Kongstad Kenneth T. , Nielsen Birgitte , Sørensen Troels E. , Balle Thomas , Jensen Anders A. , Frølund Bente
Published: August 2014

A series of bioisosteric N1‐ and N2‐substituted 5‐(piperidin‐4‐yl)‐3‐hydroxypyrazole analogues of the partial GABAAR agonists 4‐PIOL and 4‐PHP have been designed, synthesized, and characterized pharmacologically. The unsubstituted 3‐hydroxypyrazole analogue of 4‐PIOL (2 a; IC50∼300 μM) is a weak antagonist at the α1β2γ2 GABAAR, whereas substituting the N1‐ or N2‐position with alkyl or aryl substituents resulted in antagonists with binding affinities in the high nanomolar to low micromolar range at native rat GABAARs. Docking studies using a α1β2γ2 GABAAR homology model along with the obtained SAR indicate that the N1‐substituted analogues of 4‐PIOL and 4‐PHP, 2 a–k, and previously reported 3‐substituted 4‐PHP analogues share a common binding mode to the orthosteric binding site in the receptor. Interestingly, the core scaffold of the N2‐substituted analogues of 4‐PIOL and 4‐PHP, 3 b–k, are suggested to flip 180° thereby adapting to the binding pocket and addressing a cavity situated above the core scaffold.
Highly Magnetic Nanoporous Carbon/Iron‐Oxide Hybrid Materials
Authors: Alam Sher , Anand Chokkalingam , Lakhi Kripal Singh , Choy Jin‐Ho , Cha Wang Soo , Elzhatry Ahmed , Al‐deyab Salem S. , Ohya Yutaka , Vinu Ajayan
Published: August 2014

The preparation of size‐controllable Fe2O3 nanoparticles grown in nanoporous carbon with tuneable pore diameters is reported. These hybrid materials exhibit strong non‐linear magnetic properties and a magnetic moment of approximately 229 emu g−1, which is the highest value ever reported for nanoporous hybrids, and can be attributed to the nanosieve effect and the strong interaction between the nanoparticles and the carbon walls.
Ab Initio Molecular Dynamics Study of Hydrogen Cleavage by a Lewis Base [tBu3P] and a Lewis Acid [B(C6F5)3] at the Mesoscopic Level—Dynamics in the Solute–Solvent Molecular Clusters
Authors: Pu Maoping , Privalov Timofei
Published: August 2014

With the help of state‐of‐the‐art ab initio molecular dynamics methods, we investigated the reaction pathway of the {tBu3P + H2 + B(C6F5)3} system at the mesoscopic level. It is shown that: i) the onset of H2 activation is at much larger boron⋅⋅⋅phosphorus distances than previously thought; ii) the system evolves to the product in a roaming‐like fashion because of quasi‐periodic nuclear motion along the asymmetric normal mode of P⋅⋅⋅HH⋅⋅⋅B fragment; iii) transient configurations of a certain type are present despite structural interference from the solvent; iv) transient‐state configurations with sub‐picosecond lifetime have potentially interesting infrared activity in the organic solvent (toluene) as well as in the gas phase. The presented results should be helpful for future experimental and theoretical studies of frustrated Lewis pair (FLP) activity.
Functionalized Tri‐ and Tetraphosphine Ligands as a General Approach for Controlled Implantation of Phosphorus Donors with a High Local Density in Immobilized Molecular Catalysts
Authors: Beaupérin Matthieu , Smaliy Radomyr , Cattey Hélène , Meunier Philippe , Ou Jun , Toy Patrick H. , Hierso Jean‐Cyrille
Published: August 2014

Supported phosphine ligands are auxiliaries of topical academic and industrial interest in catalysis promoted by transition metals. However, both controlled implantation and controlled conformation of ligands should be achieved to produce immobilized catalysts that are able to structurally “copy” efficient homogeneous systems. We provide herein a general synthetic strategy for assembling a new class of branched tetra‐ and triphosphine ligands with a unique controlled rigid conformation, and thus providing a high local density of phosphorus atoms for extended coordination to the metal center. We prepared new functionalized cyclopentadienyl (Cp) salts to design polyphosphines that were “ready for immobilization”. These protected Cp fragments might also be of synthetic utility for generating other supported metallocenes. Tetra‐ and triphosphines were then formed and diversely functionalized for immobilization on virtually any kind of support. As evidenced by 31P NMR spectroscopy and the strong “through‐space” spin–spin TSJ(P,P) coupling observed between P atoms, these modified polyphosphines induce, when immobilized on a support, a high local concentration of phosphorus donors that are spatially very close to each other (3–5 Å). These functionalized ligands have been incorporated into polystyrene to give either soluble or insoluble polymers and on inorganic supports such as silica. We report the catalytic performance at 0.05–0.5 mol % low palladium loading of the resulting immobilized polyphosphine ligands. This study provides proof‐of‐concept of supported catalytic materials built from modular polyphosphines with a novel approach to structurally controlled polydentate heterogeneous catalysts.
Ncor1 and Ncor2 play essential but distinct roles in zebrafish primitive myelopoiesis
Authors: Li Jingyun , Li Kui , Dong Xiaohua , Liang Dong , Zhao Qingshun
Published: August 2014

Background: Although Ncor1 and Ncor2, the co‐repressors that can actively repress gene transcription through binding nuclear receptors in the absence of ligands, are crucial to vertebrate embryogenesis, their roles in its primitive myelopoiesis remain unknown. We investigated the function of ncor1 or ncor2 in zebrafish embryos by antisense morpholino knocking down technologies. Results: Development of both mfap4+ macrophages and mpx+ neutrophils was abolished in ncor2 morphants, whereas development of mpx+ neutrophils was depleted in ncor1 morphants. ncor2 was essential to the development of spi1b+ myeloid precursors but not anterior hemangioblasts whereas ncor1 was dispensable to the specification of spi1b+ myeloid precursors and anterior hemangioblasts. Overexpressing spi1b could partially rescue expressions of mfap4 and mpx in ncor2 morphants. Furthermore, overexpressing tal1/lmo2 could well rescue the defective myelopoiesis in both ncor1 and ncor2 morphants. Conclusions: Ncor1 and Ncor2 play essential but distinct roles in zebrafish primitive myelopoiesis. ncor2 could parallel with tal1/lmo2 and acted upstream of spi1b to produce mature macrophages and neutrophils during primitive myelopoiesis. The role of ncor1 in zebrafish myelopoiesis could be substituted by excessive Tal1/Lmo2. Developmental Dynamics 243:1544–1553, 2014. © 2014 Wiley Periodicals, Inc.