bluuebunny/crossref_metadata_2025 huggingface dataset:
Morrow, Reiff, Receive 2013 Space Physics and Aeronomy Richard Carrington Awards: Citation for Patricia H. Reiff
Authors: Moore Thomas Earle
Published: August 2014

Patricia Reiff has been awarded the SPARC Education and Outreach Award for her pioneering education and outreach efforts communicating excitement for, and understanding of, space and Earth science.
Tracking plasma rotation speeds in Saturn's magnetosphere
Authors: Balcerak Ernie
Published: August 2014

Researchers are learning more about the dynamics of Saturn's magnetosphere by applying a technique that is commonly used to study Earth's aurora. Using data from the magnetospheric imaging instrument on the Cassini spacecraft, Carbary and Mitchell tracked blobs of energetic neutral hydrogen atoms within Saturn's magnetosphere by creating keograms—time versus latitude plots assembled from multiple images, providing an instantaneous global view of azimuthal speeds of the blobs. The energetic neutral atoms serve as “imagers” of the ion population of a magnetosphere because they originate from charge exchange between neutral atoms and energetic ions.
Solar zenith angle does not affect Mars ionosphere's electron temperature
Authors: Wendel JoAnna
Published: August 2014

Exploration of Mars, whether by spacecraft or by humans in the far‐flung future, requires a deep understanding of Mars's ionosphere—the upper layer of atmosphere where molecules are ionized by the Sun's energy. For example, scientists on Earth trying to communicate with current and future Mars rovers are and will continue to be hindered by free electrons in the ionosphere that can absorb and reflect radio waves. Scientists therefore wonder, What are the various physical properties that can influence the behavior of Mars's ionosphere?
Aerosols from Sahara weaken cyclogenesis
Authors: Wendel JoAnna
Published: August 2014

Hot, dry air and dust in the atmosphere over the Sahara Desert—known as the Saharan Air Layer (SAL)—are thought to influence cyclone formation when they interact with the cooler, more humid air over the Atlantic Ocean. Whether the SAL inhibits the formation of cyclones or not has been hotly debated for decades.
Sea level may rise 0.5–1.2 meters by the end of the century
Authors: Wendel JoAnna
Published: August 2014

In the wake of the Intergovernmental Panel on Climate Change's (IPCC) Fifth Assessment Report, many governments around the world are scrambling to determine how to best mitigate the consequences of a warming climate. However, it is difficult to quantify the future effects of climate change in a way that has an impact on human lives. After all, a human life is microscopic compared to the time span in which the Earth will be affected by climate change.
Structure of a reconnection layer poleward of the cusp: Extreme density asymmetry and a guide field
Authors: Muzamil F. M. , Farrugia C. J. , Torbert R. B. , Pritchett P. R. , Mozer F. S. , Scudder J. D. , Russell C. T. , Sandholt P. E. , Denig W. F , Wilson L.
Published: August 2014

We present Polar observations of a reconnection layer during an inbound pass at high northern latitudes. The interplanetary field of 20 nT pointed strongly northward continuously for 13 h. Reverse polar cap convection observed repeatedly by the DMSP F13 satellite provided direct evidence of continued reconnection. Polar observed sunward and southward jets. The event was hallmarked by a density asymmetry ≈140 and moderate guide field. Disturbances in fields and plasma were much more intense on the magnetosphere (MSP) side of the current sheet (CS). A density cavity was observed at both separatrices. Isolated EN peaks occurred at the density cavity regions. The intense electric field fluctuations (≤60 mV/m) were mainly in the component normal to the CS, EN. The guide field pointed opposite to the Hall field, leading to an overall weakening of the out‐of‐plane magnetic field. A magnetic island was observed in the outflow jet. The field reversal at the CS occurred before the outflow jet, which we argue to be due to the large density asymmetry. The stagnation line was strongly shifted toward the MSP side of the CS. We compare observations with simulations which emphasize the density asymmetry and which also include a guide field, and we find good agreement. Remaining discrepancies may be explained by a density asymmetry much larger than in simulations. This is to our knowledge the first study of a high‐latitude reconnection layer with (1) an extreme density asymmetry and (2) steady and continuously strong interplanetary Bz.
On the increasing oscillation period of flows at the tailward retreating flux pileup region during dipolarization
Authors: Panov E. V. , Baumjohann W. , Kubyshkina M. V. , Nakamura R. , Sergeev V. A. , Angelopoulos V. , Glassmeier K.‐H. , Petrukovich A. A.
Published: August 2014

On 23 March 2009 between 6:00 and 6:40 UT, three Time History of Events and Macroscale Interactions during Substorms probes (P3, P4, and P5) were at about −11.5 Earth radii (RE) and two (P1 and P2) were at −14 RE downtail. The inner probes (P3–P5) started to observe oscillatory flow braking with plasma sheet dipolarization due to flux pileup at about 6:04 UT. After 6:16 UT the flux pileup region (FPR) expanded tailward as the outer probes (P1 and P2) moved closer to the neutral sheet and began to observe oscillatory braking also. During the FPR tailward expansion, the flow oscillation period increased from about 3.5 min at P3–P5 to about 6.2 min at P1 and P2. Meanwhile, as observed by the all‐sky camera at Rankin Inlet, auroral activity gradually moved northward indicating that the characteristics of oscillatory flows at the tailward retreating FPR may be crucial for understanding the magnetosphere‐ionosphere coupling.
Gravity changes and deformation at Kīlauea Volcano, Hawaii, associated with summit eruptive activity, 2009–2012
Authors: Bagnardi Marco , Poland Michael P. , Carbone Daniele , Baker Scott , Battaglia Maurizio , Amelung Falk
Published: August 2014

Analysis of microgravity and surface displacement data collected at the summit of Kīlauea Volcano, Hawaii (USA), between December 2009 and November 2012 suggests a net mass accumulation at ~1.5 km depth beneath the northeast margin of Halema‘uma‘u Crater, within Kīlauea Caldera. Although residual gravity increases and decreases are accompanied by periods of uplift and subsidence of the surface, respectively, the volume change inferred from the modeling of interferometric synthetic aperture radar deformation data can account for only a small portion (as low as 8%) of the mass addition responsible for the gravity increase. We propose that since the opening of a new eruptive vent at the summit of Kīlauea in 2008, magma rising to the surface of the lava lake outgasses, becomes denser, and sinks to deeper levels, replacing less dense gas‐rich magma stored in the Halema‘uma‘u magma reservoir. In fact, a relatively small density increase (<200 kg m−3) of a portion of the reservoir can produce the positive residual gravity change measured during the period with the largest mass increase, between March 2011 and November 2012. Other mechanisms may also play a role in the gravity increase without producing significant uplift of the surface, including compressibility of magma, formation of olivine cumulates, and filling of void space by magma. The rate of gravity increase, higher than during previous decades, varies through time and seems to be directly correlated with the volcanic activity occurring at both the summit and the east rift zone of the volcano.
Seasonal surface layer dynamics and sensitivity to runoff in a high Arctic fjord (Young Sound/Tyrolerfjord, 74°N)
Authors: Bendtsen Jørgen , Mortensen John , Rysgaard Søren
Published: August 2014

Runoff from the Greenland Ice Sheet, local glaciers, and snowmelt along the northeastern Greenland coastline has a significant impact on coastal water masses flowing south toward Denmark Strait. Very few direct measurements of runoff currently exist in this large area, and the water masses near the coast are also difficult to measure due to the presence of icebergs and sea ice. Measurements from the Zackenberg Research station, located in Young Sound/Tyrolerfjord in northeast Greenland (74°N), provide some of the few observations of hydrographic, hydrologic, and atmospheric parameters from this remote area. Here we analyze measurements from the fjord and also measurements in the ambient water masses, which are found in the outer fjord and between the fjord and the East Greenland Current and validate and apply a numerical model of the fjord. A model sensitivity study allows us to constrain runoff estimates for the area. We also show that a total runoff between 0.9 and 1.4 km3 in 2006 is in accordance with observed surface salinities and calculated freshwater content in the fjord. This indicates that earlier reported runoff to the area is significantly underestimated and that melt from glaciers and the Greenland Ice Sheet in this region may be up to 50% larger than the current estimate. Model simulations indicate the presence of a cold low‐saline coastal water mass formed by runoff from fjords north of the Young Sound/Tyrolerfjord system. Simulations of passive and age tracers show that residence time of river water during the summer period is about 1 month in the inner part of the fjord.
Temporal variability of observed and simulated hyperspectral reflectance
Authors: Roberts Y. L. , Pilewskie P. , Feldman D. R. , Kindel B. C. , Collins W. D.
Published: August 2014

Multivariate analysis techniques were used to quantify and compare the spectral and temporal variability of observed and simulated shortwave hyperspectral Earth reflectance. The observed reflectances were measured by the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument between 2002 and 2010. The simulated reflectances were calculated using climate Observing System Simulation Experiments (OSSEs), which used two Intergovernmental Panel on Climate Change AR4 scenarios (constant CO2 and A2 emission) to drive Moderate Resolution Atmospheric Transmission simulations. Principal component (PC) spectral shapes and time series exhibited evidence of physical variables including cloud reflectance, vegetation and desert albedo, and water vapor absorption. Comparing the temporal variability of the OSSE‐simulated and SCIAMACHY‐measured hyperspectral reflectance showed that their Intertropical Convergence Zone‐like Southern Hemisphere (SH) tropical PC1 ocean time series had a 90° phase difference. The observed and simulated PC intersection quantified their similarity and directly compared their temporal variability. The intersection showed that despite the similar spectral variability, the temporal variability of the dominant PCs differed as in, for example, the 90° phase difference between the SH tropical intersection PC1s. Principal component analysis of OSSE reflectance demonstrated that the spectral and centennial variability of the two cases differed. The A2 PC time series, unlike the constant CO2 time series, exhibited centennial secular trends. Singular spectrum analysis isolated the A2 secular trends. The A2 OSSE PC1 and PC4 secular trends matched those in aerosol optical depth and total column precipitable water, respectively. This illustrates that time series of hyperspectral reflectance may be used to identify and attribute secular climate trends with a sufficiently long measurement record and high instrument accuracy.
Analysis of global land surface albedo climatology and spatial‐temporal variation during 1981–2010 from multiple satellite products
Authors: He Tao , Liang Shunlin , Song Dan‐Xia
Published: August 2014

For several decades, long‐term time series data sets of multiple global land surface albedo products have been generated from satellite observations. These data sets have been used as one of the key variables in climate change studies. This study aims to assess the surface albedo climatology and to analyze long‐term albedo changes, from nine satellite‐based data sets for the period 1981–2010, on a global basis. Results show that climatological surface albedo data sets derived from satellite observations can be used to validate, calibrate, and further improve surface albedo simulations and parameterizations in current climate models. However, the albedo products derived from the International Satellite Cloud Climatology Project and the Global Energy and Water Exchanges Project have large seasonal biases. At latitudes higher than 50°, the maximal difference in winter zonal albedo ranges from 0.1 to 0.4 among the nine satellite data sets. Satellite‐based albedo data sets agree relatively well during the summer at high latitudes, with a standard deviation of 0.04 for the 70°–80° zone in both hemispheres. The fine‐resolution (0.05°) data sets agree well with each other for all the land cover types in middle to low latitudes; however, large spread was identified for their albedos at middle to high latitudes over land covers with mixed snow and sparse vegetation. By analyzing the time series of satellite‐based albedo products over the past three decades, albedo of the Northern Hemisphere was found to be decreasing in July, likely due to the shrinking snow cover. Meanwhile, albedo in January was found to be increasing, likely because of the expansion of snow cover in northern winter. However, to improve the albedo estimation at high latitudes, and ultimately the climate models used for long‐term climate change studies, a still better understanding of differences between satellite‐based albedo data sets is required.
Multiple characteristic model‐based golden‐section adaptive control: Stability and optimization
Authors: Huang Huang
Published: August 2014

The characteristic model‐based golden‐section adaptive control (CM‐GSAC) law has been developed for over 20 years in China with a broad range of applications in various fields. However, quite a few theoretical problems remain open despite its satisfying performance in practice. This paper revisits the stability of the CM‐GSAC from its very beginning and explores the underlying implications of the so‐called golden‐section parameter l2≈0.618. The closed‐loop system, which consists of the CM and the GSAC, is a discrete time‐varying system, and its stability is discussed from three perspectives. First, attentions have been paid to select the optimal controller coefficients such that the closed‐loop system exhibits the best transient performance in the worst case. Second, efforts are made to improve the robustness in the presence of parameter estimation errors, which provide another choice when designing the adaptive controller. Finally, by measuring the slowly time‐varying nature in an explicit inequality form, a bridge is built between the instantaneous stability and the time‐varying stability. In order to relax the constraints on the parameter bounds of the CM, the GSAC is further extended to multiple CMs, which shows more satisfying tracking performance than that of the traditional multiple model adaptive control method. Copyright © 2014 John Wiley & Sons, Ltd.
Plasmonic Nanocavity Organic Light‐Emitting Diode with Significantly Enhanced Light Extraction, Contrast, Viewing Angle, Brightness, and Low‐Glare
Authors: Ding Wei , Wang Yuxuan , Chen Hao , Chou Stephen Y.
Published: August 2014

One central challenge in LEDs is to increase light extraction; but for display applications, other factors may have equal significance, such as ambient‐light absorption, contrast, viewing angle, image sharpness, brightness, and low‐glare. However, current LED structures enhance only some of the factors, while degrading the others. Here, a new organic LED (OLED) structure is proposed and demonstrated, with a novel plasmonic nanocavity, termed “plasmonic cavity with subwavelength hole‐array” (PlaCSH), and exhibits experimentally significant enhancements of all above factors with unprecedented performances. Compared to the conventional OLEDs (the same but without PlaCSH), PlaCSH‐OLEDs achieve experimentally: i) 1.57‐fold higher external‐quantum‐efficiency and light‐extraction‐efficiency (29%/32% without lens, 55%/60% with lens)—among the highest reported; ii) ambient‐light absorption not only 2.5‐fold higher but also broad‐band (400 nm) and nearly angle and polarization independent, leading to lower‐glare; iii) fivefold higher contrast (12 000 for 140 lux ambient‐light); iv) viewing angle tunable by the cavity length; v) 1.86‐fold higher normal‐view‐brightness; and vi) uniform color over all emission angles. The PlaCSH is an excellent optical antenna—excellent in both radiation and absorption of light. Furthermore, PlaCSH‐OLEDs, a simple structure to produce, are fabricated using nanoimprint over large‐area (≈1000 cm2), hence scalable to wallpaper size.
Multifunctional Three‐Dimensional T‐Junction Graphene Micro‐Wells: Energy‐Efficient, Plasma‐Enabled Growth and Instant Water‐Based Transfer for Flexible Device Applications
Authors: Kumar Shailesh , van der Laan Timothy , Rider Amanda Evelyn , Randeniya Lakshman , Ostrikov Kostya (Ken)
Published: August 2014

The “third‐generation” 3D graphene structures, T‐junction graphene micro‐wells (T‐GMWs) are produced on cheap polycrystalline Cu foils in a single‐step, low‐temperature (270 °C), energy‐efficient, and environment‐friendly dry plasma‐enabled process. T‐GMWs comprise vertical graphene (VG) petal‐like sheets that seemlessly integrate with each other and the underlying horizontal graphene sheets by forming T‐junctions. The microwells have the pico‐to‐femto‐liter storage capacity and precipitate compartmentalized PBS crystals. The T‐GMW films are transferred from the Cu substrates, without damage to the both, in de‐ionized or tap water, at room temperature, and without commonly used sacrificial materials or hazardous chemicals. The Cu substrates are then re‐used to produce similar‐quality T‐GMWs after a simple plasma conditioning. The isolated T‐GMW films are transferred to diverse substrates and devices and show remarkable recovery of their electrical, optical, and hazardous NO2 gas sensing properties upon repeated bending (down to 1 mm radius) and release of flexible trasparent display plastic substrates. The plasma‐enabled mechanism of T‐GMW isolation in water is proposed and supported by the Cu plasma surface modification analysis. Our GMWs are suitable for various optoelectronic, sesning, energy, and biomedical applications while the growth approach is potentially scalable for future pilot‐scale industrial production.
Printable, Transparent, and Flexible Touch Panels Working in Sunlight and Moist Environments
Authors: Vuorinen Tiina , Zakrzewski Mari , Rajala Satu , Lupo Donald , Vanhala Jukka , Palovuori Karri , Tuukkanen Sampo
Published: August 2014

The ongoing revolution of touch‐based user interfaces sets new requirements for touch panel technologies, including the need to operate in a wide range of environments. Such touch panels need to endure moisture and sunlight. Moreover, they often need to be curved or flexible. Thus, there is a need for new technologies suitable, for example, for home appliances used in the kitchen or the bathroom, automotive applications, and e‐paper. In this work, the development of transparent and flexible touch panels for moist environments is reported. A piezoelectric polymer, poly(vinylidene difluoride) (PVDF), is used as a functional substrate material. Transparent electrodes are fabricated on both sides of a PVDF film using a graphene‐based ink and spray coating. The excellent performance of the touch panels is demonstrated in moist and underwater conditions. Also, the transparent device shows very small pyroelectric response to radiative heating in comparison to a non‐transparent device. Solution processable electrode materials in combination with functional substrates allow the low‐cost and high‐throughput manufacturing of touch panels using printing technologies.
Tunable Enhancement of Raman Scattering in Graphene‐Nanoparticle Hybrids
Authors: Balasubramanian Kannan , Zuccaro Laura , Kern Klaus
Published: August 2014

The realization of graphene‐gold‐nanoparticle (G‐AuNP) hybrids is presented here through a versatile electrochemical approach, which allows the continuous tuning of the size and density of the particles obtainable on the graphene surface. Raman scattering from graphene, which is significantly enhanced in such hybrids, is systematically investigated as a function of the size and density of particles at the same location. In agreement with theory, it is shown that the Raman enhancement is tunable by varying predominantly the density of the nanoparticles. Furthermore, it is observed that the increase in Raman cross‐section and the strength of Raman enhancement varies as a function of the frequency of the vibrational mode, which may be correlated with the plasmonic fingerprint of the deposited AuNPs. In addition to this electromagnetic enhancement, support is found for a chemical contribution through the occurrence of charge transfer from the AuNPs onto graphene. Finally, G‐AuNP hybrids can be efficiently utilized as SERS substrates for the detection of specifically bound non‐resonant molecules, whose vibrational modes can be unambiguously identified. With the possibility to tune the degree of Raman enhancement, this is a platform to design and engineer SERS substrates to optimize the detection of trace levels of analyte molecules.
The Effect of Thermal Reduction on the Water Vapor Permeation in Graphene Oxide Membranes
Authors: Andrikopoulos Konstantinos S. , Bounos Giannis , Tasis Dimitrios , Sygellou Lamprini , Drakopoulos Vassilios , Voyiatzis Georgios A.
Published: August 2014

In the present study, the influence of the thermal reduction on the water vapor transmission properties of thin graphene oxide (GO) membranes is evaluated. The macroscopically measured property of the Water Vapor Transmission Rate (WVTR) exhibits step like dependence contrary to the gradual microscopic structural alterations identified by several techniques (XPS, FTIR and XRD) applied in situ during the thermal annealing process. Three distinct regions of WVTR‐values associated with distinct interlayer distances i.e., >7.5 Å, ∼6 Å and <6 Å are essentially observed which may be compared to the findings of the recently reported first principle calculations. Our experimental results enable the understanding of the water vapor unimpeded transmission through the layers of the oxygen rich GO nanostructured membranes and consequently facilitate the design of functional membranes for separation applications.
Ultrafast Photoswitching in a Copper‐Nitroxide‐Based Molecular Magnet
Authors: Kaszub Wawrzyniec , Marino Andrea , Lorenc Maciej , Collet Eric , Bagryanskaya Elena G. , Tretyakov Evgeny V. , Ovcharenko Victor I. , Fedin Matvey V.
Published: August 2014

Molecular compounds with photoswitchable magnetic properties have been intensively investigated over the last decades due to their prospective applications in nanoelectronics, sensing and magnetic data storage. The family of copper‐nitroxide‐based molecular magnets represents a new promising type of photoswitchable compounds. We report the first study of these appealing systems using femtosecond optical spectroscopy. We unveil the mechanism of ultrafast (<50 fs) spin state photoswitching and establish its principal differences compared to other photoswitchable magnets. On this basis, we propose potential advantages of copper‐nitroxide‐based molecular magnets for the future design of ultrafast magnetic materials.
Coupling of Sterically Hindered Trisubstituted Olefins and Benzocyclobutenones by CC Activation: Total Synthesis and Structural Revision of Cycloinumakiol
Authors: Xu Tao , Dong Guangbin
Published: August 2014

The first total syntheses of the proposed structure of cycloinumakiol (1) and its C5 epimer (18) are achieved in a concise and efficient fashion. Starting from the known 3‐hydroxybenzocyclobutenone, 1 and 18 are obtained in nine and five steps with overall yields of 15 % and 33 %, respectively. The key for the success of this approach is the use of a catalytic CC activation strategy for constructing the tetracyclic core of 1 through carboacylation of a sterically hindered trisubstituted olefin with benzocyclobutenone. In addition, the structure of the natural cycloinumakiol was reassigned to 19‐hydroxytotarol (7) through X‐ray diffraction analysis. This work demonstrates the potential of CC activation for streamlining complex natural product synthesis.
Structural Basis for the Identification of an i‐Motif Tetraplex Core with a Parallel‐Duplex Junction as a Structural Motif in CCG Triplet Repeats
Authors: Chen Yi‐Wen , Jhan Cyong‐Ru , Neidle Stephen , Hou Ming‐Hon
Published: August 2014

CCG triplet repeats can fold into tetraplex structures, which are associated with the expansion of (CCG)n trinucleotide sequences in certain neurological diseases. These structures are stabilized by intertwining i‐motifs. However, the structural basis for tetraplex i‐motif formation in CCG triplet repeats remains largely unknown. We report the first crystal structure of a CCG‐repeat sequence, which shows that two dT(CCG)3A strands can associate to form a tetraplex structure with an i‐motif core containing four C:C+ pairs flanked by two G:G homopurine base pairs as a structural motif. The tetraplex core is attached to a short parallel‐stranded duplex. Each hairpin itself contains a central CCG loop in which the nucleotides are flipped out and stabilized by stacking interactions. The helical twists between adjacent cytosine residues of this structure in the i‐motif core have an average value of 30°, which is greater than those previously reported for i‐motif structures.
A Cytoprotective and Degradable Metal–Polyphenol Nanoshell for Single‐Cell Encapsulation
Authors: Park Ji Hun , Kim Kyunghwan , Lee Juno , Choi Ji Yu , Hong Daewha , Yang Sung Ho , Caruso Frank , Lee Younghoon , Choi Insung S.
Published: August 2014

Single‐cell encapsulation promises the cytoprotection of the encased cells against lethal stressors, reminiscent of the sporulation process in nature. However, the development of a cytocompatible method for chemically mimicking the germination process (i.e., shell degradation on‐demand) has been elusive, despite the shell degradation being pivotal for the practical use of functional cells as well as for single cell‐based biology. We report that an artificial shell, composed of tannic acid (TA) and FeIII, on individual Saccharomyces cerevisiae controllably degrades on‐demand, while protecting the yeast from multiple external aggressors, including UV‐C irradiation, lytic enzymes, and silver nanoparticles. Cell division is suppressed by the TA–FeIII shell, but restored fully upon shell degradation. The formation of a TA–FeIII shell would provide a versatile tool for achieving the chemical version of “sporulation and germination”.
Phosphine‐Catalyzed Annulations of 4,4‐Dicyano‐2‐Methylenebut‐3‐enoates with Maleimides and Maleic Anhydride
Authors: Zhang Xiao‐Nan , Chen Gen‐Qiang , Tang Xiang‐Ying , Wei Yin , Shi Min
Published: August 2014

A novel phosphine‐catalyzed [4+1] annulation of maleimides with 4,4‐dicyano‐2‐methylenebut‐3‐enoates has been developed to afford spirocyclic products, and the maleimides serves as C1 synthons. Moreover, a phosphine‐catalyzed formal [3+2] annulation between 4,4‐dicyano‐2‐methylenebut‐3‐enoates and maleic anhydride has been also achieved, and maleic anhydride behaved as a C3 synthon in the reaction, thus efficiently affording the functionalized cyclopentenones. A stable phosphinium‐containing zwitterionic compound is the key reactive intermediate in both annulations and was successfully isolated. Plausible mechanisms have been proposed on the basis of control experiments and deuterium‐labeling experiments.
Synthesis, Physicochemical, and Anticonvulsant Properties of New N‐Mannich Bases Derived from Pyrrolidine‐2,5‐dione and Its 3‐Methyl Analog
Authors: Rybka Sabina , Obniska Jolanta , Rapacz Anna , Filipek Barbara , Kamiński Krzysztof
Published: August 2014

A series of 22 new N‐[(4‐phenylpiperazin‐1‐yl)‐methyl]‐3‐methyl‐pyrrolidine‐2,5‐dione and pyrrolidine‐2,5‐dione derivatives were synthesized and evaluated for their anticonvulsant activities in the maximum electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure tests after intraperitoneal injection into mice. The neurotoxicity was determined applying the rotarod test. The in vivo results in mice showed that seven compounds were effective in the MES or/and scPTZ seizure tests. The quantitative evaluation in both tests after i.p. administration into mice revealed that the most active compounds were N‐[{4‐(3,4‐dichlorophenyl)‐piperazin‐1‐yl}‐methyl]‐3‐methylpyrrolidine‐2,5‐dione (12) with ED50 = 16.13 mg/kg (MES), ED50 = 133.99 mg/kg (scPTZ) and N‐[{4‐(3,4‐dichlorophenyl)‐piperazin‐1‐yl}‐methyl]‐pyrrolidine‐2,5‐dione (23) with ED50 = 37.79 mg/kg (MES), ED50 = 128.82 mg/kg (scPTZ), whereas N‐[{4‐(3‐trifluoromethylphenyl)‐piperazin‐1‐yl}‐methyl]‐pyrrolidine‐2,5‐dione (24) was effective only in the MES test with ED50 = 16.37 mg/kg. These molecules showed higher potency and also lower neurotoxicity than the reference antiepileptic drugs such as ethosuximide and valproic acid.
Maximizing binding capacity for protein A chromatography
Authors: Ghose Sanchayita , Zhang Jennifer , Conley Lynn , Caple Ryan , Williams Kevin P. , Cecchini Douglas
Published: August 2014

Advances in cell culture expression levels in the last two decades have resulted in monoclonal antibody titers of ≥10 g/L to be purified downstream. A high capacity capture step is crucial to prevent purification from being the bottleneck in the manufacturing process. Despite its high cost and other disadvantages, Protein A chromatography still remains the optimal choice for antibody capture due to the excellent selectivity provided by this step. A dual flow loading strategy was used in conjunction with a new generation high capacity Protein A resin to maximize binding capacity without significantly increasing processing time. Optimum conditions were established using a simple empirical Design of Experiment (DOE) based model and verified with a wide panel of antibodies. Dynamic binding capacities of >65 g/L could be achieved under these new conditions, significantly higher by more than one and half times the values that have been typically achieved with Protein A in the past. Furthermore, comparable process performance and product quality was demonstrated for the Protein A step at the increased loading. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1335–1340, 2014
Age patterns of Kaposi's sarcoma incidence in a cohort of HIV‐infected men
Authors: Luu Hung N. , Amirian E. Susan , Chiao Elizabeth Y. , Scheurer Michael E.
Published: August 2014

The life expectancy for HIV‐positive individuals has improved over time due to increasing access to highly active antiretroviral therapy (HAART). Yet, as the HIV‐positive population ages, their risk of developing cancers also increases. Studies of Kaposi's sarcoma (KS) among elderly HIV‐infected persons are quite limited. We examined the age patterns of KS incidence and an association between age and KS risk in a US cohort of 3458 HIV‐infected men, the Multicenter AIDS Cohort Study (MACS). Poisson distribution was used to calculate incidence rates and respective 95% confidence intervals (95% CIs). Cox proportional hazards regression was performed to examine the association between age and KS risk. There were 534 incident KS cases with a total follow‐up time of 25,134 person‐years. The overall KS incidence rate was 2.13 per 100 person‐years (95% CI: 1.95–2.32) (Non‐HAART users‐ever: 5.57 per 100 person‐years [95% CI: 5.09–6.10]; HAART users‐ever: 0.39 per 100 person‐years [95% CI: 0.31–0.51]). Overall, KS frequency and incidence declined with age, even in the oldest age group (ptrend < 0.0001). However, among non‐HAART users‐ever, the oldest age group had the highest incidence rate ratio compared to younger individuals [15.01, 95% CI: 6.12–44.22]). While the incidence of KS decreased with age, older HIV‐infected persons who do not receive HAART are still at increased risk of KS. As KS remains an important malignancy among HIV‐infected persons, earlier HIV diagnoses and HAART initiation, particularly in older HIV‐infected persons is warranted.
SCAI expert consensus statement for renal artery stenting appropriate use
Authors: Parikh Sahil A. , Shishehbor Mehdi H. , Gray Bruce H. , White Christopher J. , Jaff Michael R.
Published: August 2014

The pathophysiology of atherosclerotic renal artery stenosis (RAS) includes activation of the renin‐angiotensin‐aldosterone axis with resultant renovascular hypertension. Renal artery stenting has emerged as the primary revascularization strategy in most patients with hemodynamically significant atherosclerotic RAS. Despite the frequency with which hemodynamically significant RAS is observed and high rates of technical success of renal artery stenting, there remains considerable debate among experts regarding the role of medical therapy versus revascularization for renovascular hypertension. Modern, prospective, multicenter registries continue to demonstrate improvement in systolic and diastolic blood pressure with excellent safety profiles in patients with RAS. Modern randomized, controlled clinical trials of optimal medical therapy versus renal stenting particularly designed to demonstrate preservation in renal function after renal artery stenting have demonstrated limited benefit. However, these trials frequently excluded patients that may benefit from renal artery stenting. This document was developed to guide physicians in the modern practical application of renal stenting, to highlight the current limitations in the peer‐reviewed literature, to suggest best‐practices in the performance of renal stenting and to identify opportunities to advance the field. © 2014 Wiley Periodicals, Inc.
Synergy in the Catalytic Activity of Bimetallic Nanoparticles and New Synthetic Methods for the Preparation of Fine Chemicals
Authors: Notar Francesco Irene , Fontaine‐Vive Fabien , Antoniotti Sylvain
Published: August 2014

Metal nanoparticles receive tremendous interest as alternative catalysts in a quest to fill the gap between homogeneous and heterogeneous catalysis with selective and sophisticated reactions that occur in highly recyclable and scalable processes. In this area of research that is growing rapidly, we would like to focus on bimetallic nanoparticles and on how these particular materials have been used recently as nanocatalysts in fine‐chemicals synthesis and transformations. The synergistic effects observed with these nanocatalysts, either as nanoalloys or core–shell objects, that accounts for their superior activity and efficiency are discussed.
Discovery of false identification using similarity difference in GC–MS‐based metabolomics
Authors: Kim Seongho , Zhang Xiang
Published: August 2014

Compound identification is a critical process in metabolomics. The widely used approach for compound identification in gas chromatography–mass spectrometry‐based metabolomics is spectrum matching, in which the mass spectral similarity between an experimental mass spectrum and each mass spectrum in a reference library is calculated. While various similarity measures have been developed to improve the overall accuracy of compound identification, little attention has been paid to reducing the false discovery rate. We, therefore, develop an approach for controlling the false identification rate using the distribution of the difference between the first and second highest spectral similarity scores. We further propose a model‐based approach to achieving a desired true positive rate. The developed method is applied to the National Institute of Standards and Technology mass spectral library, and its performance is compared with that of the conventional approach that uses only the maximum spectral similarity score. The results show that the developed method achieves a significantly higher F1 score and positive predictive value than did the conventional approach. Copyright © 2014 John Wiley & Sons, Ltd.
syn‐1,2‐Carboboration of Alkynes with Borenium Cations
Authors: Cade Ian A. , Ingleson Michael J.
Published: August 2014

The reaction of 8‐(trimethylsiloxy)quinoline (QOTMS) with BCl3 and (aryl)BCl2 forms QOBCl2 and QOBCl(aryl). The subsequent addition of stoichiometric AlCl3 follows one of two paths, dependent on the steric demands of the QO ligand and the electrophilicity of the resulting borenium cation. The phenyl‐ and 5‐hexylthienylborenium cations, QOBPh+ and QOBTh+, are formed, whereas QOBCl+ is not. Instead, AlCl3 preferentially binds with QOBCl2 at oxygen, forming QOBCl2⋅AlCl3, rather than abstracting chloride. A modest increase in the steric demands around oxygen, by installing a methyl group at the 7‐position of the quinolato ligand, switches the reactivity with AlCl3 back to chloride abstraction, allowing formation of QOBCl+. All the prepared borenium cations are highly chlorophilic and exhibit significant interaction with AlCl4− resulting in an equilibrium concentration of Lewis acidic “AlCl3” species. The presence of “AlCl3” species limits the alkyne substrates compatible with these borenium systems, with reaction of [QOBPh][AlCl4] with 1‐pentyne exclusively yielding the cyclotrimerised product, 1,3,5‐tripropylbenzene. In contrast, QOBPh+ and QOBTh+ systems effect the syn‐1,2‐carboboration of 3‐hexyne. DFT calculations at the M06‐2X/6‐311G(d,p)/PCM(DCM) level confirm that the higher migratory aptitude of Ph versus Me leads to a lower barrier to 1,2‐carboboration relative to 1,1‐carboboration.
Stoichiometrically Controlled Revocable Self‐Assembled “Spiro” versus Quadruple‐Stranded “Double‐Decker” Type Coordination Cages
Authors: Bandi Sreenivasulu , Pal Amlan K. , Hanan Garry S. , Chand Dillip Kumar
Published: August 2014

The simple combination of PdII with the tris‐monodentate ligand bis(pyridin‐3‐ylmethyl) pyridine‐3,5‐dicarboxylate, L, at ratios of 1:2 and 3:4 demonstrated the stoichiometrically controlled exclusive formation of the “spiro‐type” Pd1L2 macrocycle, 1, and the quadruple‐stranded Pd3L4 cage, 2, respectively. The architecture of 2 is elaborated with two compartments that can accommodate two units of fluoride, chloride, or bromide ions, one in each of the enclosures. However, the entry of iodide is altogether restricted. Complexes 1 and 2 are interconvertible under suitable conditions.
How Different Characterization Techniques Elucidate the Nature of the Gold Species in a Polycrystalline Au/TiO2 Catalyst
Authors: Grünert Wolfgang , Großmann Dennis , Noei Heshmat , Pohl Marga‐Martina , Sinev Ilya , De Toni Andrea , Wang Yuemin , Muhler Martin
Published: August 2014

TiO2‐supported gold species were prepared via the deposition‐precipitation route, with conservation of the initial speciation by freeze‐drying. The structural and electronic properties of the Au species were investigated by X‐ray absorption spectroscopy, electron microscopy, and IR spectroscopy of adsorbed CO in four states. Exclusively AuIII was deposited on the TiO2 surface in patches ranging from isolated Au ions to three‐dimensional clusters. This paper illustrates in detail the unique contributions of all characterization techniques to this structural model.
5‐(1H‐Tetrazolyl)‐2‐Hydroxy‐Tetrazole: A Selective 2N‐Monoxidation of Bis(1H‐Tetrazole)
Authors: Klapötke Thomas M. , Kurz Matthias Q. , Scharf Regina , Schmid Philipp C. , Stierstorfer Jörg , Sućeska Muhamed
Published: August 2014

Sodium 5‐cyanotetrazolate sesquihydrate (1) is prepared from sodium azide and two equivalents of sodium cyanide under acidic conditions. 1 is then N‐oxidized with Oxone to sodium 5‐cyanotetrazolate monohydrate (2). Compound 2 is treated with sodium azide and a Lewis acid to form 5‐(1H‐tetrazolyl)‐2‐hydroxytetrazole monohydrate (3). Compound 3 can be deprotonated twice by various bases to give ionic derivatives such as the bis(hydroxylammonium) (4), bis(hydrazinium) (6), bis(guanidinium) (7), bis(aminoguanidinium) (8), bis(ammonium) (9), and diaminouronium (11) salt. In addition, compound 3 can only be deprotonated once, as demonstrated by the hydroxylammonium (4) and triaminoguanidinium (10) salts. Compounds 2–5 and 10–11 are structurally characterized by single‐crystal X‐ray diffraction. Additionally, compounds 2–11 are characterized by using NMR and vibrational (IR, Raman) spectroscopy as well as mass spectrometry and elemental analysis. Their thermal behaviors are studied from differential thermal analysis measurements, and the sensitivities of the compounds toward shock, friction, and electrostatic discharge are determined. In addition, the heats of formation are calculated (atomization method, CBS‐4M enthalpies), and several detonation/propulsion parameters are computed with the EXPLO5 code.
Development and Potential Theranostic Applications of a Self‐Assembled Hybrid of Magnetic Nanoparticle Clusters with Polysaccharide Nanogels
Authors: Katagiri Kiyofumi , Ohta Keiko , Sako Kaori , Inumaru Kei , Hayashi Koichiro , Sasaki Yoshihiro , Akiyoshi Kazunari
Published: August 2014

A new organic–inorganic hybrid was generated by self‐assembly of nanosized polymer hydrogels (nanogels) and Fe3O4nanoparticles (NPs) for potential biomedical applications. By using the tetrahydrofuran (THF) injection method, hydrophobized Fe3O4NPs were complexed through hydrophobic interactions with amphiphilic polysaccharide nanogels. The obtained hybrid showed high colloidal stability and dispersibility in aqueous media. The number of Fe3O4NP aggregates was controlled by changing the concentration of the Fe3O4NPs in THF. The hybrid displayed greater enhancement than existing contrast media inT2magnetic resonance imaging because of the optimal agglomeration of Fe3O4NPs following their complexation with nanogels. Furthermore, the hybrid generated heat in response to alternating magnetic‐field irradiation. The increase in temperature was controlled by adjusting the concentration of the hybrid and the amplitude of the magnetic field, which indicates that the hybrid is also suitable for magnetic hyperthermia therapy.
Circulating SFRP5 levels are elevated in drug‐naïve recently diagnosed type 2 diabetic patients as compared with prediabetic subjects and controls
Authors: Canivell Silvia , Rebuffat Sandra , G. Ruano Elena , Kostov Belchin , Sisó‐Almirall Antoni , Novials Anna , Ceriello Antonio , Gomis Ramon
Published: August 2014

Background

Secreted frizzled‐related protein 5 (SFRP5) has been linked to obesity. Results are conflicting regarding its association with type 2 diabetes (T2D) in humans. We aimed to investigate circulating SFRP5 in prediabetes and T2D and its potential association with parameters of insulin resistance and beta‐cell function.

Methods

We studied 70 drug‐naïve T2D patients, 70 prediabetic subjects and 70 controls. All subjects were body mass index matched to the T2D patients and overweight or obese. SFRP5, hormones and cytokines levels were measured by ELISA.

Results

Serum SFRP5 levels were elevated in T2D patients as compared with prediabetic subjects (median 15.6, interquartile range [9–24.5] ng/mL vs 9.8 [5–14.2] ng/mL, p < 0.001, respectively) and controls (15.6 [9–24.5] ng/mL vs 10.4 [6.7‐16.6] ng/mL, P < 0.001, respectively). No differences were found in serum SFRP5 levels between prediabetic subjects and controls (9.8 [5–14.2] ng/mL vs 10.4 [6.7–16.6] ng/mL, p = 0.472, respectively). After adjusting for potential confounders (age, gender, body mass index, triglycerides, high‐density lipoprotein cholesterol and blood pressure), T2D was still associated with higher values of SFRP5 as compared with prediabetes in multinomial logistic regression analysis (fully adjusted odds ratio 3.50, 95% confidence interval 1.40–8.79, p = 0.008). The association was more subtle when comparing T2D with normal glucose tolerance state (fully adjusted odds ratio 2.18, 95% confidence interval 0.91–5.21, p = 0.078).

Conclusions

Circulating SFRP5 levels were independently associated with T2D as compared with prediabetes and normal glucose tolerance state. Copyright © 2014 John Wiley & Sons, Ltd.
Adjunctive graded body image exposure for eating disorders: A randomized controlled initial trial in clinical practice
Authors: Trottier Kathryn , Carter Jacqueline C. , MacDonald Danielle E. , McFarlane Traci , Olmsted Marion P.
Published: August 2014

Objective

Graded body image exposure is a key component of CBT for eating disorders (EDs). However, despite being a highly anxiety‐provoking intervention, its specific effectiveness is unknown. The aims of this initial study were to investigate the feasibility and preliminary effectiveness of individualized graded body image exposure to a range of feared/avoided body image‐related situations in a sample of partially remitted ED patients.

Method

Forty‐five female adult participants were randomly assigned to maintenance treatment as usual (MTAU) only or MTAU plus five sessions of graded body image exposure.

Results

The graded body image exposure intervention led to large improvements in body avoidance as measured by two different methods. In addition, there was evidence of a significant impact of body image exposure on the overvaluation of shape, but not weight, 5 months after treatment.

Discussion

Taken together, the current results provide evidence of the feasibility of adjunctive individualized graded body image exposure within a clinical treatment program and suggest that graded body image exposure reduces body avoidance behaviors in partially remitted ED patients. Our findings suggest that individualized graded body image exposure shows promise as an intervention targeting the overvaluation of shape in EDs. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2015; 48:494–504)
The (lack of) effect of alprazolam on eating behavior in anorexia nervosa: A preliminary report
Authors: Steinglass Joanna E. , Kaplan Simona C. , Liu Ying , Wang Yuanjia , Walsh B. Timothy
Published: August 2014

Objective

Anxiety is a prominent symptom in anorexia nervosa (AN), and higher pre‐meal anxiety has been associated with lower caloric intake. Yet, the causal relationship has not been assessed. We proposed that reducing anxiety with a short acting benzodiazepine would increase caloric intake among individuals with AN.

Method

In a randomized, double‐blind, placebo controlled cross‐over study, we administered alprazolam 0.75 mg to inpatients with AN (n = 17) and assessed caloric intake in a laboratory test meal. Within‐subject differences in caloric intake, anxiety, and fatigue were compared between alprazolam and placebo days.

Results

Caloric intake did not differ on alprazolam versus placebo (t15 = 1.72, p = .11). Alprazolam did not reduce anxiety, but was associated with increased fatigue.

Discussion

This study was not able to evaluate the causal role of anxiety in meal intake among individuals with AN, as alprazolam did not alter anxiety symptoms. These data further suggest that the therapeutic role for short‐acting benzodiazepines in AN is likely limited. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:901–904)