bluuebunny/crossref_metadata_2025 huggingface dataset:
Widespread excess ice in Arcadia Planitia, Mars
Authors: Bramson Ali M. , Byrne Shane , Putzig Nathaniel E. , Sutton Sarah , Plaut Jeffrey J. , Brothers T. Charles , Holt John W.
Published: August 2015

The distribution of subsurface water ice on Mars is a key constraint on past climate, while the volumetric concentration of buried ice (pore‐filling versus excess) provides information about the process that led to its deposition. We investigate the subsurface of Arcadia Planitia by measuring the depth of terraces in simple impact craters and mapping a widespread subsurface reflection in radar sounding data. Assuming that the contrast in material strengths responsible for the terracing is the same dielectric interface that causes the radar reflection, we can combine these data to estimate the dielectric constant of the overlying material. We compare these results to a three‐component dielectric mixing model to constrain composition. Our results indicate a widespread, decameters‐thick layer that is excess water ice ~104 km3 in volume. The accumulation and long‐term preservation of this ice is a challenge for current Martian climate models.
Field‐aligned currents in Saturn's northern nightside magnetosphere: Evidence for interhemispheric current flow associated with planetary period oscillations
Authors: Hunt G. J. , Cowley S. W. H. , Provan G. , Bunce E. J. , Alexeev I. I. , Belenkaya E. S. , Kalegaev V. V. , Dougherty M. K. , Coates A. J.
Published: August 2015

We investigate the magnetic perturbations associated with field‐aligned currents observed on 34 Cassini passes over the premidnight northern auroral region during 2008. These are found to be significantly modulated not only by the northern planetary‐period oscillation (PPO) system, similar to the southern currents by the southern PPO system found previously, but also by the southern PPO system as well, thus providing the first clear evidence of PPO‐related interhemispheric current flow. The principal field‐aligned currents of the two PPO systems are found to be co‐located in northern ionospheric colatitude, together with the currents of the PPO‐independent (subcorotation) system, located between the vicinity of the open‐closed field boundary and field lines mapping to ~9 Saturn radius (Rs) in the equatorial plane. All three systems are of comparable magnitude, ~3 MA in each PPO half‐cycle. Smaller PPO‐related field‐aligned currents of opposite polarity also flow in the interior region, mapping between ~6 and ~9 Rs in the equatorial plane, carrying a current of ~ ±2 MA per half‐cycle, which significantly reduce the oscillation amplitudes in the interior region. Within this interior region the amplitudes of the northern and southern oscillations are found to fall continuously with distance along the field lines from the corresponding hemisphere, thus showing the presence of cross‐field currents, with the southern oscillations being dominant in the south, and modestly lower in amplitude than the northern oscillations in the north. As in previous studies, no oscillations related to the opposite hemisphere are found on open field lines in either hemisphere.
Tsunami inundation from heterogeneous earthquake slip distributions: Evaluation of synthetic source models
Authors: Davies Gareth , Horspool Nick , Miller Victoria
Published: August 2015

This study investigates whether eight different synthetic finite fault models (SFFM) can simulate stochastic earthquake‐tsunami with similar statistical properties to “real” earthquake‐tsunami events, where the latter are represented using heterogeneous slip distributions from 66 Finite Fault Inversions (FFI) for oceanic subduction interface earthquakes. A new method is derived to estimate SFFM parameters from FFI, and predictive relations between the earthquake moment magnitude and the SFFM corner wave numbers are developed to support model applications. SFFM with more capacity to spatially localize slip are better able to simulate higher slip regions on the FFI, and this strongly influences their associated tsunami inundation, which is computed in two dimensions over idealized topography. The best performing SFFM generates tsunami inundation which envelopes the FFI inundation in 81% of cases using 10 synthetic events (close to the ideal value of 82%), while the other SFFM show greater tendencies to underestimate inundation. These differences are related to the capacity of each SFFM to produce spatially localized slip distributions. None of the SFFM showed a tendency to overpredict inundation. The results highlight that SFFM cannot be assumed to reliably quantify uncertainties in the tsunami inundation of real earthquakes, and the use of untested SFFM could create nonconservative bias in tsunami hazard assessments. However, the most successful model used here performs quite well, although it may still underestimate inundation more often than an optimal model.
Wind‐wave source functions in opposing seas
Authors: Langodan Sabique , Cavaleri Luigi , Viswanadhapalli Yesubabu , Hoteit Ibrahim
Published: August 2015

The Red Sea is a challenge for wave modeling because of its unique two opposed wave systems, forced by opposite winds and converging at its center. We investigate the different physical aspects of wave evolution and propagation in the convergence zone. The two opposing wave systems have similar amplitude and frequency, each driven by the action of its own wind. Wave patterns at the center of the Red Sea, as derived from extensive tests and intercomparison between model and measured data, suggest that the currently available wave model source functions may not properly represent the evolution of the local fields that appear to be characterized by a less effective wind input and an enhanced white‐capping. We propose and test a possible simple solution to improve the wave‐model simulation under opposing winds and waves condition.
Thermal stability of ice on Ceres with rough topography
Authors: Hayne P. O. , Aharonson O.
Published: August 2015

The dwarf planet Ceres may have an ice‐rich crust, and subsurface ice exposed by impacts or endogenic activity would be subject to sublimation. We model surface and subsurface temperatures on Ceres to assess lifetimes of water ice and other volatiles. Topographic shadowing allows a small but nonnegligible fraction (∼0.4%) of Ceres' surface to be perennially below the ∼110 K criterion for 1 Gyr of stability. These areas are found above 60° latitude. Other molecules (CH3OH, NH3, SO2, and CO2) may be cold trapped in smaller abundances. A model for the transport, gravitational escape, and photoionization of H2O molecules suggests net accumulation in the cold traps. Buried ice is stable within a meter for > 1 Gyr at latitudes higher than ∼50°. An illuminated polar cap of water ice would be stable within a few degrees of the poles only if it maintained a high albedo (>0.5) at present obliquity. If the obliquity exceeded 5° in the geologically recent past, then a putative polar cap would have been erased. At latitudes 0°–30°, ice is stable under solar illumination only briefly (∼10–100 years), unless it has high albedo and thermal inertia, in which case lifetimes of > 104 years are possible. Finally, a small hemispheric asymmetry exists due to the timing of Ceres' perihelion passage, which would lead to a detectable enhancement of ice in the northern hemisphere if the orbital elements vary slowly relative to the ice accumulation rate. Our model results are potentially testable during the Dawn science mission.
Poleward migration of eddy‐driven jets
Authors: Chemke R. , Kaspi Y.
Published: August 2015

Poleward migration of eddy‐driven jets is found to occur in the extratropics when the subtropical and eddy‐driven jets are clearly separated, as achieved by simulations at high‐rotation rates. The poleward migration of these eddy‐driven baroclinic jets over time is consistent with variation of eddy momentum flux convergence and baroclinicity across the width of the jet. We demonstrate this using a high‐resolution idealized GCM where we systematically examine the eddy‐driven jets over a wide range of rotation rates (up to 16 times the rotation rate of Earth). At the flanks of the jets, the poleward migration is caused by a poleward bias in baroclinicity across the width of the jet, estimated through measures such as Eady growth rate and supercriticality. The poleward biased baroclinicity is due to the meridional variation of the Coriolis parameter, which causes a poleward bias of the eddy momentum flux convergence. At the core of the jets, the poleward biased eddy momentum flux convergence relative to the mean jet deflects over time the baroclinicity and the jets poleward. As the rotation rate is increased, and more (narrower) jets emerge the migration rate becomes smaller due to less eddy momentum flux convergence over the narrower baroclinic zones. We find a linear relation between the migration rate of the jets and the net eddy momentum flux convergence across the jets. This poleward migration might be related to the slow poleward propagation of temporal anomalies of zonal winds observed in the upper troposphere.
The tectonic evolution of a critical segment of the Dinarides‐Alps connection: Kinematic and geochronological inferences from the Medvednica Mountains, NE Croatia
Authors: van Gelder I. E. , Matenco L. , Willingshofer E. , Tomljenović B. , Andriessen P. A. M. , Ducea M. N. , Beniest A. , Gruić A.
Published: August 2015

The transition zone between the Alps and Dinarides is a key area to investigate kinematic interactions of neighboring orogens with different subduction polarities. A study combining field kinematic and sedimentary data, microstructural observations, thermochronological data (Rb‐Sr and fission track), and regional structures in the area of Medvednica Mountains has revealed a complex polyphase tectonic evolution. We document two novel stages of extensional exhumation. The first stage of extension took place along a Late Cretaceous detachment following the late Early Cretaceous nappe stacking, burial, and greenschist facies metamorphism. Two other shortening events that occurred during the latest Cretaceous‐Oligocene were followed by a second event of extensional exhumation, characterized by asymmetric top‐NE extension during the Miocene. Top‐NW thrusting took place subsequently during the Pliocene inversion of the Pannonian Basin. The Cretaceous nappe burial, Late Cretaceous extension, and the Oligocene(‐Earliest Miocene) contraction are events driven by the Alps evolution. In contrast, the latest Cretaceous‐Eocene deformation reflects phases of Dinaridic contraction. Furthermore, the Miocene extension and subsequent inversion display kinematics similar with observations elsewhere in the Dinarides and Eastern Alps. All these processes demonstrate that the Medvednica Mountains were affected by Alpine phases of deformations to a much higher degree than previously thought. Similarly with what has been observed in other areas of contractional polarity changes, such as the Mediterranean, Black Sea, or New Guinea systems, the respective tectonic events are triggered by rheological weak zones which are critical for localizing the deformation created by both orogens.
Microgrid Electrode for Si Microwire Solar Cells with a Fill Factor of Over 80%
Authors: Um Han‐Don , Hwang Inchan , Kim Namwoo , Yu Young J. , Wober Munib , Kim Ka‐Hyun , Seo Kwanyong
Published: August 2015

Here, a novel microgrid top electrode for highly efficient radial‐junction Si microwire solar cells is demonstrated. The microgrid electrode minimizes optical and electrical losses, thus ensuring proper function of the shallow (sheet resistance of ≈100 Ω sq−1) junction emitter. This leads to effective collection of the photocarriers from the shallow junction emitter through the top electrode without severe Auger/surface recombination, improving the overall power conversion efficiency of the Si microwire solar cell. With an optimized microgrid structure, 1 cm2 microwire solar cells show a conversion efficiency of up to 16.5%, with an open‐circuit voltage of 565.2 mV and a short‐circuit current density of 35.9 mA·cm−2; this conversion efficiency is 72% higher than that of solar cells with an edge electrode (9.6%). Further, an ≈1 μm thick Ni electrode that is formed by electroplating considerably reduces the metal and contact resistances, which reproducibly yields a fill factor of over 80% (max 81.2%). Thus, the use of a novel microgrid to construct an ideal metal/emitter interface presents a unique opportunity to develop highly efficient microwire solar cells.
Understanding the External Quantum Efficiency of Organic Homo‐Tandem Solar Cells Utilizing a Three‐Terminal Device Architecture
Authors: Bahro Daniel , Koppitz Manuel , Mertens Adrian , Glaser Konstantin , Mescher Jan , Colsmann Alexander
Published: August 2015

A fundamental analysis of the external quantum efficiency (EQE) of organic tandem solar cells with equal absorbers in both subcells (homo‐tandem solar cells) is presented. Providing direct access to both subcells by introducing a conductive intermediate polymer electrode into the recombination zone, without changing the optical and electric device properties, the three‐terminal device becomes a proxy to the two‐terminal tandem solar cell properties. From the spectrally resolved EQE of the subcells in three‐terminal configuration wavelength and intensity of suitable bias light as well as bias voltage are determined that in turn allow for accurate EQE measurements of the common two‐terminal tandem solar cells. Theoretic considerations allow the prediction of the tandem solar cell's EQE from its subcells' EQEs as well as the prediction of the tandem cell EQE under monochromatic bias light illumination being in excellent agreement with experimental results. All findings discussed herein can be applied to more common hetero‐tandem solar cell architectures likewise.
Differences in mortality and morbidity according to gestational ages and birth weights in infants with trisomy 18
Authors: Imai Ken , Uchiyama Atsushi , Okamura Tomoka , Ago Mako , Suenaga Hideyo , Sugita Eri , Ono Hideko , Shuri Kyoko , Masumoto Kenichi , Totsu Satsuki , Nakanishi Hidehiko , Kusuda Satoshi
Published: August 2015

The aim of this study was to clarify the effects of gestational age and birth weight on outcomes of the infants. Medical records of 36 infants with trisomy 18 admitted to Tokyo Women's Medical University Hospital from 1991 to 2012 were reviewed retrospectively. We compared clinical characteristics between term infants (n = 15) and preterm infants (n = 21). There were one very‐low‐birth‐weight (VLBW) term infant (5%) and 12 VLBW preterm infants (80%). Although there were no significant differences in clinical characteristics and provided management between the two groups, none of the preterm infants achieved survival to discharge. On the other hand, 6 of 21 term infants (29%) achieved survival to discharge (P < 0.05). Similar results were obtained for comparisons between the VLBW infants and non‐VLBW infants. Multiple logistic regression analysis revealed that shorter gestational age had a more negative impact than lower birth weight to survival to discharge in infants with trisomy 18. In both preterm and term groups, the infants who died before 30 days commonly died of respiratory failure or apnea. Whereas, the infants who survived more than 30 days mostly died of heart failure. © 2015 The Authors.American Journal of Medical Genetics Part APublished by Wiley Periodicals, Inc.
Genetic analysis of SLC41A1 in Chinese Parkinson's disease patients
Authors: Wang Ling , Cheng Lan , Li Nan‐Nan , Yu Wen‐Juan , Sun Xiao‐Yi , Peng Rong
Published: August 2015

Sequence variants in SLC41A1 (solute carrier family 41 member 1) within the PARK16 locus have been reported to be associated with Parkinson's disease (PD). We performed direct DNA sequencing of the SLC41A1 gene in 100 early‐onset PD cases. A novel intron variant (NM_173854.5:c.993‐90delA) and a known synonymous‐coding variant (NM_173854.5:c.339 C>T, causing p.Thr113Thr, rs11240569) were identified in the SLC41A1 gene. Then we genotyped the rs11240569 variant in a total of 2237 Han Chinese comprising of 1063 sporadic PD and 1174 controls to investigate the association with risk of PD, we also conducted further stratified analysis according to age at onset and compared the clinical characteristics of CC + CT subjects with TT subjects. In this study, we confirmed that the C allele of SLC41A1 (rs11240569) polymorphism reduces the risk to develop sporadic PD (P = 0.018). Additionally, subjects with CC + CT genotypes have a reduced risk compared to those with TT genotype (P = 0.022), the association was modestly seen among the younger age group (P = 0.05), but was not significant among the older age group (P = 0.641). Besides, we demonstrated that CC + CT subjects cannot be distinguished from TT subjects based on their clinical features. Our study, the first demonstrates that SLC41A1 (rs11240569) is associated with a lower risk of PD in a Han Chinese population from mainland China. © 2015 Wiley Periodicals, Inc.
Technical note: An in vitro study of dental microwear formation using the BITE Master II chewing machine
Authors: Hua Li‐Cheng , Brandt Elizabeth T. , Meullenet Jean‐Francois , Zhou Zhong‐Rong , Ungar Peter S.
Published: August 2015

Dental microwear has been used for decades to reconstruct the diets of fossil hominins and bioarchaeological populations. The basic theory has been that hard‐brittle foods (e.g., nuts, bone) require crushing and leave pits as they are pressed between opposing cheek‐tooth surfaces, whereas soft‐tough foods (e.g., grass blades, meat) require shearing and leave scratches as they are dragged along opposing surfaces that slide past one another. However, recent studies have called into question the efficacy of microwear as an indicator of diet. One issue has been the limited number of in vitro studies providing empirical evidence for associations between microwear pattern and chewing behavior. We here describe a new study using a chewing simulator, the BITE Master II, to examine the effects of angle of approach between opposing teeth and food consistency on microwear surface texture. Results indicate that opposing teeth that approach one another: 1) perpendicular to the occlusal plane (crushing) result in pits; 2) parallel to the occlusal plane (shearing) result in striations in the direction of movement; and 3) oblique to the occlusal plane (45°) result in both striations and pits. Results further suggest that different food types and abrasive loads affect the propensity to accumulate microwear features independent of feature shapes. Am J Phys Anthropol 158:769–775, 2015. © 2015 Wiley Periodicals, Inc.
Enantioselective Palladium‐Catalyzed CH Functionalization of Indoles Using an Axially Chiral 2,2′‐Bipyridine Ligand
Authors: Gao Xiang , Wu Bo , Huang Wen‐Xue , Chen Mu‐Wang , Zhou Yong‐Gui
Published: August 2015

A palladium‐catalyzed enantioselective CH functionalization of indoles was achieved with an axially chiral 2,2′‐bipyridine ligand, thus providing the desired indol‐3‐acetate derivatives with up to 98 % ee. Moreover, the reaction protocol was also effective for asymmetric OH insertion reaction of phenols using α‐aryl‐α‐diazoacetates. This represents the first successful application of bipyridine ligands with axial chirality in palladium‐catalyzed carbene migratory insertion reactions.
A Supramolecular Antibiotic Switch for Antibacterial Regulation
Authors: Bai Haotian , Yuan Huanxiang , Nie Chenyao , Wang Bing , Lv Fengting , Liu Libing , Wang Shu
Published: August 2015

A supramolecular antibiotic switch is described that can reversibly “turn‐on” and “turn‐off” its antibacterial activity on demand, providing a proof‐of‐concept for a way to regulate antibacterial activity of biotics. The switch relies on supramolecular assembly and disassembly of cationic poly(phenylene vinylene) derivative (PPV) with cucurbit[7]uril (CB[7]) to regulate their different interactions with bacteria. This simple but efficient strategy does not require any chemical modification on the active sites of the antibacterial agent, and could also regulate the antibacterial activity of classical antibiotics or photosensitizers in photodynamic therapy. This supramolecular antibiotic switch may be a successful strategy to fight bacterial infections and decrease the emergence of bacterial resistance to antibiotics from a long‐term point of view.
Kompensation von Pulsimperfektionen in der Festkörper‐NMR‐ Spektroskopie: ein Schlüssel zu verbesserter Reproduzierbarkeit und Effizienz
Authors: Wittmann Johannes J. , Takeda Kazuyuki , Meier Beat H. , Ernst Matthias
Published: August 2015

Das Potential und die Vielseitigkeit der NMR‐Spektroskopie beruhen auf der Möglichkeit, NMR‐Wechselwirkungen gezielt mittels Radiofrequenzpulssequenzen zu beeinflussen. Allerdings unterscheiden sich die Radiofrequenzfelder (RF), die auf die Spins wirken, von denen, die der Experimentator am Spektrometer programmiert. So genannte Pulstransienten, d. h. Abweichungen des RF‐Feldes in Amplitude und Phase von den erwarteten Werten, können einen erheblichen Einfluss auf die Effizienz von Pulssequenzen haben und daher zu unterschiedlichen Ergebnissen führen. Wir zeigen, dass transientenkompensierte Pulse sowohl die Effizienz als auch die Reproduzierbarkeit von NMR‐Experimenten deutlich erhöhen können. Die Implementierung basiert auf den Charakteristiken des Schwingkreises und nicht auf einer experimentellen Optimierung des NMR‐Signals. Wir zeigen, wie die Pulssequenz für die Verwendung transientenkompensierter Pulse verändert werden muss. Die Effizienz und die Reproduzierbarkeit der transientenkompensierten Sequenz sind gegenüber der ursprünglichen POST‐C7‐Sequenz deutlich verbessert.
B(C6F5)3‐katalysierter Diwasserstofftransfer von einem ungesättigten Kohlenwasserstoff auf einen anderen
Authors: Chatterjee Indranil , Qu Zheng‐Wang , Grimme Stefan , Oestreich Martin
Published: August 2015

Es wird über eine übergangsmetallfreie Transferhydrierung von 1,1‐disubstituierten Alkenen berichtet, in der ein Cyclohexa‐1,4‐dien die formale Diwasserstoffquelle darstellt. Der Prozess beginnt mit einer B(C6F5)3‐vermittelten Hydridabstraktion vom Diwasserstoffsurrogat unter Bildung eines Brønsted‐sauren Wheland‐Komplexes sowie [HB(C6F5)3]−. Eine Abfolge aus Protonen‐ und Hydridübertragungen auf das Alkensubstrat liefert dann das Alkan. Obwohl mehrere Carbeniumionzwischenstufen beteiligt sind, werden konkurrierende Reaktionswege, beispielsweise Diwasserstofffreisetzung und kationische Dimerisierungen von Reaktanten, weitgehend unterdrückt. Dies wird durch den Einsatz von Cyclohexa‐1,4‐dienen mit Methylgruppen an den C1‐ und C5‐Positionen sowie am C3‐Kohlenstoffatom, an dem die Hydridabstraktion stattfindet, ermöglicht. Die Konzentration an Alken ist eine weitere entscheidende Einflussgröße. Die unterschiedlichen Reaktionspfade wurden berechnet, woraus sich ein mechanistisches Bild ergibt, das mit den experimentellen Beobachtungen vollständig in Einklang ist.
Cyclic [2]Catenane Dimers, Trimers, and Tetramers
Authors: Wu Yi‐Wei , Tung Shun‐Te , Lai Chien‐Chen , Liu Yi‐Hung , Peng Shie‐Ming , Chiu Sheng‐Hsien
Published: August 2015

Dimeric, trimeric, and tetrameric cyclic [2]catenanes have been prepared directly through one‐pot sodium‐ion‐templated dynamic imine formation from a diamine and a tetraaldehyde. NaBH4 mediated reduction of the labile imino bonds of these cyclic [2]catenane oligomers, followed by methylation of the resulting secondary amino groups enabled the isolation and characterization of oligomeric cyclic [2]catenanes as stable, covalently linked compounds.
Ribosome Subunit Stapling for Orthogonal Translation in E. coli
Authors: Fried Stephen D. , Schmied Wolfgang H. , Uttamapinant Chayasith , Chin Jason W.
Published: August 2015

The creation of orthogonal large and small ribosomal subunits, which interact with each other but not with endogenous ribosomal subunits, would extend our capacity to create new functions in the ribosome by making the large subunit evolvable. To this end, we rationally designed a ribosomal RNA that covalently links the ribosome subunits via an RNA staple. The stapled ribosome is directed to an orthogonal mRNA, allowing the introduction of mutations into the large subunit that reduce orthogonal translation, but have minimal effects on cell growth. Our approach provides a promising route towards orthogonal subunit association, which may enable the evolution of key functional centers in the large subunit, including the peptidyl‐transferase center, for unnatural polymer synthesis in cells.
Large Magnetization and Frustration Switching of Magnetoresistance in the Double‐Perovskite Ferrimagnet Mn2FeReO6
Authors: Arévalo‐López Angel M. , McNally Graham M. , Attfield J. Paul
Published: August 2015

Ferrimagnetic A2BB′O6 double perovskites, such as Sr2FeMoO6, are important spin‐polarized conductors. Introducing transition metals at the A‐sites offers new possibilities to increase magnetization and tune magnetoresistance. Herein we report a ferrimagnetic double perovskite, Mn2FeReO6, synthesized at high pressure which has a high Curie temperature of 520 K and magnetizations of up to 5.0 μB which greatly exceed those for other double perovskite ferrimagnets. A novel switching transition is discovered at 75 K where magnetoresistance changes from conventional negative tunneling behavior to large positive values, up to 265 % at 7 T and 20 K. Neutron diffraction shows that the switch is driven by magnetic frustration from antiferromagnetic Mn2+ spin ordering which cants Fe3+ and Re5+ spins and reduces spin‐polarization. Ferrimagnetic double perovskites based on A‐site Mn2+ thus offer new opportunities to enhance magnetization and control magnetoresistance in spintronic materials.
Compensating Pulse Imperfections in Solid‐State NMR Spectroscopy: A Key to Better Reproducibility and Performance
Authors: Wittmann Johannes J. , Takeda Kazuyuki , Meier Beat H. , Ernst Matthias
Published: August 2015

The power and versatility of NMR spectroscopy is strongly related to the ability to manipulate NMR interactions by the application of radio‐frequency (rf) pulse sequences. Unfortunately, the rf fields seen by the spins differ from the ones programmed by the experimentalist. Pulse transients, i.e., deviations of the amplitude and phase of the rf fields from the desired values, can have a severe impact on the performance of pulse sequences and can lead to inconsistent results. Here, we demonstrate how transient‐compensated pulses can greatly improve the efficiency and reproducibility of NMR experiments. The implementation is based on a measurement of the characteristics of the resonance circuit and does not rely on an experimental optimization of the NMR signal. We show how the pulse sequence has to be modified to use it with transient‐compensated pulses. The efficiency and reproducibility of the transient‐compensated sequence is greatly superior to the original POST‐C7 sequence.
Near‐Infrared‐Activated Nanocalorifiers in Microcapsules: Vapor Bubble Generation for In Vivo Enhanced Cancer Therapy
Authors: Shao Jingxin , Xuan Mingjun , Dai Luru , Si Tieyan , Li Junbai , He Qiang
Published: August 2015

Photothermal therapy based on gold nanostructures has been widely investigated as a state‐of‐the‐art noninvasive therapy approach. Because single nanoparticles cannot harvest sufficient energy, self‐assemblies of small plasmonic particles into large aggregates are required for enhanced photothermal performance. Self‐assembled gold nanorods in lipid bilayer‐modified microcapsules are shown to localize at tumor sites, generate vapor bubbles under near‐infrared light exposure, and subsequently damage tumor tissues. The polyelectrolyte multilayer enables dense packing of gold nanorods during the assembly process, which leads to the formation of vapor bubbles around the excited capsules. The resulting vapor bubbles achieve a high efficiency of suppressing tumor growth compared to single gold nanorods. In vivo experiments demonstrated the ability of soft‐polymer multilayer microcapsules to cross the biological barriers of the body and localize at target tissues.
pH‐sensitive hydroxyethyl starch–doxorubicin conjugates as antitumor prodrugs with enhanced anticancer efficacy
Authors: Zhu Yu , Yao Xuemei , Chen Xiaofei , Chen Li
Published: August 2015

Doxorubicin (DOX) is a widely used chemotherapeutic drug for the treatment of several types of cancers, which has limitation in clinical applications because of severe heart toxicity. Herein, to reduce the fast clearance from the blood system and the severe systemic toxicity caused by the nonspecific protein adsorption, a pH‐sensitive drug delivery system with higher drug conjugated content was prepared by conjugating DOX onto hydroxyethyl starch (HES) with a pH‐sensitive hydrazone bond. In normal physiological environment, the release of DOX conjugated onto HES was slight which could be neglected without any side effect. However, in an acidic environment mimicking the tumor microenvironment, this pH‐sensitive hydrazone linkage provided a controlled and sustained release of DOX over a period of more than 3 days. The conjugates had good biocompatibility, long circulation, and lower cytotoxicity, which could efficiently be transferred into HeLa and HepG2 cells and release the conjugated drug. Based on these promising properties, these HES–DOX conjugates outline the significant potential for future biomedical application in the controlled release of antitumor drugs. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42778.
The end game inKuhlthau'sISP Model: Knowledge construction for grade 8 students researching an inquiry‐based history project
Authors: Cole Charles , Beheshti Jamshid , Abuhimed Dhary , Lamoureux Isabelle
Published: August 2015

This article reports on a field study of the information behavior ofGrade 8 students researching an inquiry‐based class history project.Kuhlthau's 7‐stageInformationSearchProcess(ISP)model forms the conceptual framework for the study. The aim of the study was to define an end game for theISPmodel by answering the following question: How do the student participants' feelings, thoughts, and information behavior lead to the construction of new knowledge? Study findings tentatively indicate that knowledge construction results from an iterative process between the student and information, which can be divided into 3 phases. In the first phase, the students formulate questions from their previous knowledge to start knowledge construction; in the second phase, newly found topic information causes students to ask questions; and in the third phase, the students answer the questions asked by this newly found topic information. Based on these results andKuhlthau's ownISPstage 7 assessment definition of theISPmodel end game, we propose a model of knowledge construction inserted as an extra row in theISPmodel framework.
Evaluation of the citation matching algorithms of CWTS and iFQ in comparison to the Web of science
Authors: Olensky Marlies , Schmidt Marion , van Eck Nees Jan
Published: August 2015

The results of bibliometric studies provided by bibliometric research groups, for example, the Centre for Science and Technology Studies (CWTS) and the Institute for Research Information and Quality Assurance (iFQ), are often used in the process of research assessment. Their databases use Web of Science (WoS) citation data, which they match according to their own matching algorithms—in the case of CWTS for standard usage in their studies and in the case of iFQ on an experimental basis. Because the problem of nonmatched citations in the WoS persists due to inaccuracies in the references or inaccuracies introduced in the data extraction process, it is important to ascertain how well these inaccuracies are rectified in these citation matching algorithms. This article evaluates the algorithms of CWTS and iFQ in comparison to the WoS in a quantitative and a qualitative analysis. The analysis builds upon the method and the manually verified corpus of a previous study. The algorithm of CWTS performs best, closely followed by that of iFQ. The WoS algorithm still performs quite well (F1 score: 96.41%), but shows deficits in matching references containing inaccuracies. An additional problem is posed by incorrectly provided cited reference information in source articles by the WoS.
Optimal model‐based design of the twin‐column CaptureSMB process improves capacity utilization and productivity in protein A affinity capture
Authors: Baur Daniel , Angarita Monica , Müller‐Späth Thomas , Morbidelli Massimo
Published: August 2015

Multi‐column chromatographic processes have recently been developed for protein A affinity chromatography to efficiently capture monoclonal antibodies from cell culture supernatant. In this work, the novel twin‐column CaptureSMB process was compared to a batch capture process with dual loading flow rate to identify performance gains. As a case study, the isolation of a monoclonal antibody with the Amsphere JWT‐203 protein A resin was investigated. Using model based optimization, both processes were optimized and compared over a wide range of operating conditions. A trade‐off between productivity and capacity utilization was found, and the resulting pareto‐curves showed that CaptureSMB dominates batch, except at very low productivity values. With a feed titer of 1.2 mg mL−1, CaptureSMB could reach a productivity of up to 19.5 mg mL−1 h−1 experimentally, while maintaining relatively high capacity utilization of 63.8%. On the other hand, at maximum capacity utilization of 95.5%, a productivity of 10.2 mg mL−1 h−1 could be reached. This corresponds to a performance improvement with respect batch operation of about 25% in capacity utilization and 40% in productivity, for given yield and purity. CaptureSMB therefore offers a greatly increased performance over batch capture.
Synthesis, Characterization, and DFT Studies of Four Dinuclear Copper(II) Complexes with Aromatic Carboxylate Ligands: Cu2(L)4·(CH3OH)2
Authors: Zhang Qi , Yu Liang Min , Ni Chun Hua , Li Xin , Li Xia
Published: August 2015

Four dinuclear copper(II) complexes, Cu2(L1

–4)4·(CH3OH)2(1–4) (HL1
 = m‐anisic acid, HL2
 = p‐anisic acid, HL3
 = m‐toluic acid, HL4
 = p‐toluic acid) were synthesized and characterized by IR spectroscopy, elemental analysis, and X‐ray powder and single crystal diffraction. All of the complexes are consisting of two Cu(II) cations, four L ligands and two methanol molecules, in which the L ligands are coordinated with copper cations by bidentate bridging coordination mode. There exists hydrogen bond interaction or CH…π interaction in the complexes, forming three‐dimensional network structures. Theoretical study of the complexes was carried out by density functional theory B3LYP method.
Random‐number Seed Selection Problem in Monte Carlo Simulation of Two‐Dimensional Dielectric Pseudo‐spin Ising Hamiltonian System
Authors: Kim Se‐Hun
Published: August 2015

We investigate the dependence of Monte Carlo (MC) calculations for two‐dimensional ferroelectrics on random‐number generators by using the fixed seeds and variable time and date seeds. TheMCresults obtained by using different seeds are elucidated using auto‐correlation functions and the temperature dependence of transverse dielectric constants. The dielectric properties of the pseudo‐spin Ising model obtained using the Metropolis statistical methods are discussed by the quality of randomness.
A Facile Approach for the Synthesis of ZnO@C Core@Shell Hexagonal Nanorods and their Conversion to Carbon Nanotubes
Authors: Shima Hossain , Hossain Muhammad Mohsin , Hahn Jae Ryang
Published: August 2015

An efficient one‐step thermolysis method is developed to fabricate an optically active and well‐ordered array of zinc oxide (ZnO)@C core@shell hexagonal (ZCCSH) nanorods. These nanorods containing oxygen vacancy defects are synthesized using zinc acetate dihydrate under sealed conditions by a thermolysis reaction, and exhibit strong light absorption throughout the visible region and in most of the near‐IR region. ZCCSH nanorods are converted to carbon nanotubes (CNTs) by a simple acid treatment with a high dispersion concentration (1.83 mg/mL) in an organic solvent. The CNTs exhibit good electrical conductivity (6100 S/m). The morphology, structure, and interface characteristics of ZCCSH and CNTs are investigated.
Crime and mortality in a population‐based nationwide 1981 birth cohort: Results from the FinnCrime study
Authors: Elonheimo Henrik , Sillanmäki Lauri , Sourander André
Published: August 2015

Background

Offending is known to be associated with various health problems and premature death, but previous studies on associations between offending and mortality have often been only with men, convicted offenders or highly selected samples. A more sensitive measure of offending may be preferable when trying to understand the extent of health disadvantages among people who offend.

Aims

The aim of this paper was to study the associations between investigated offending, death and causes of death in a nationally representative birth cohort.

Methods

A broad concept of offending was used such that people who had had any contact with the police because they had been suspected of crime were included. Offending data were obtained from the National Police Register for 5405 men and women born in Finland in 1981, spanning their ages 15–30 years; mortality data were received from Statistics Finland. Offending was classified into four categories by frequency: none, 1–4 different offence contacts, 5–27 and 28 or more. Causes of death were categorised into natural, accidents, suicide or homicide. Of the cohort, 2304 (43%) had offended and 57 (1.1%) had died. Associations between offending, mortality and causes of death were analysed, controlling for parental education level and family structure in childhood.

Results

The mortality rate was higher among offenders than non‐offenders, increasing with rising frequency of offending. The most frequent offenders were nearly 30 times more likely to have died by age 30 than non‐offenders (odds ratio 28.6, confidence interval 12.1–67.5); risk was higher for female than male offenders. Death among offenders was less likely to be from natural causes.

Implications

A heightened risk of premature death is the ultimate form of adverse outcome for offenders. Offenders' health is likely to need more attention as part of their overall management, for recidivists in particular. In our study, offenders' only certain criminal justice contact was with the police, so it may be that the police should take a greater role in signposting them towards health services. Offender treatment is needed not only to protect potential victims but also offenders themselves. Copyright © 2015 John Wiley & Sons, Ltd.
A novel method to prevent recurrent balloon rupture during dilation of heavily calcified conduits in preparation for transcatheter pulmonary valve placement
Authors: Abu Hazeem Anas , Aldoss Osamah , Fagan Thomas
Published: August 2015

Introduction

A 24‐year‐old female presented for percutaneous pulmonary valve placement. She was born with tetralogy of Fallot and had initial palliation with a Blalock–Taussig shunt followed by complete repair at age of 4 years including placement of a homograft conduit in the right ventricle to pulmonary artery position. She had developed severe obstruction in the conduit.

Procedure

Angiography showed a heavily calcified conduit with moderate insufficiency. During pre‐dilation, a total of six balloons ruptured due to heavy conduit calcification prior to reaching desired inflation diameter. Subsequently, double balloon technique was attempted using two 9‐mm Conquest balloons. One of the conquest balloons was then replaced by 16‐mm Atlas balloon and conduit dilation was performed. At full inflation, the Conquest balloon ruptured. The deflated ruptured Conquest balloon was kept in the conduit and the Atlas balloon was exchanged for 18 and then 20‐mm Atlas balloons and both were used to dilate the conduit. The deflated ruptured Conquest balloon protected the Atlas balloons and conduit angioplasty proceeded successfully without further rupture of any balloon. Subsequently, four stents were placed in the conduit followed by delivery of Melody Valve using a 20‐mm Ensemble system with excellent results.

Conclusion

This case illustrates a novel method of using the body of a ruptured balloon to protect subsequent balloons from rupture due to heavy conduit calcification. This method requires the presence of two venous access lines but might save time, effort, and cost from repeated balloon ruptures. © 2015 Wiley Periodicals, Inc.
Diagnosis of intrachromosomal amplification of chromosome 21 (iAMP21) by molecular cytogenetics in pediatric acute lymphoblastic leukemia
Authors: Duployez Nicolas , Boudry‐Labis Elise , Decool Gauthier , Grzych Guillaume , Grardel Nathalie , Abou Chahla Wadih , Preudhomme Claude , Roche‐Lestienne Catherine
Published: August 2015

Key Clinical Message

Intrachromosomal amplification of chromosome 21 (iAMP21) defines a distinct cytogenetic subgroup of B‐cell precursor acute lymphoblastic leukemia (BCP‐ALL) with poor prognosis that should be investigated in routine practice. Single‐nucleotide polymorphism (SNP)‐array provides a useful method to detect such cases showing a highly characteristic profile.
Graphenes as Metal‐free Catalysts for the Oxidative Depolymerization of Lignin Models
Authors: Blandez Juan F. , Navalón Sergio , Alvaro Mercedes , Garcia Hermenegildo
Published: August 2015

Graphene oxide promotes the oxidative degradation of α‐guaiacylglycerol‐β‐guaiacyl ether, a lignin model compound, in different solvents including acetonitrile, toluene and water mainly to guaiacol, 2‐methoxyquinone, vanillic acid and coniferyl aldehyde. Reduced graphene oxide and B‐doped graphene exhibit similar activity as graphene oxide. Control experiments indicate that metal impurities should play a marginal role in the observed catalytic activity.
Photochemical Reduction of Carbon Dioxide to Formic Acid using Ruthenium(II)‐Based Catalysts and Visible Light
Authors: Rosas‐Hernández Alonso , Junge Henrik , Beller Matthias
Published: August 2015

A photocatalytic system that consists of an Ir‐based photosensitizer and a RuII bipyridine catalyst was developed for the selective reduction of CO2 to formic acid using triethanolamine as the electron donor. Catalyst turnover numbers up to 526 and a selectivity of 80 % towards formic acid were observed if the photocatalytic reaction was performed with [Ir(ppy)2(bpy)]PF6 (ppy=2‐(pyridine‐2‐yl)benzene‐1‐ide, bpy=2,2′‐bipyridine) as the photosensitizer and [Ru(bpy)2(Cl)(CO)]PF6 as the catalyst under visible‐light irradiation (λ=400–700 nm). Interestingly, this photocatalytic system showed activity for the photoreduction of Na2CO3 to formic acid as well. The investigation of different ruthenium(II) catalysts revealed the positive influence of carbonyl ligands coordinated to the metal center. The enhancement of the catalytic activity is explained by a more favorable electron transfer from the photosensitizer to the catalyst, which is supported by the redox potentials of the complexes.
H2S Reactive Absorption from Off‐Gas in a Spray Column: Insights from Experiments and Modeling
Authors: Bashipour Fatemeh , Khorasani Saied Nouri , Rahimi Amir
Published: August 2015

H2S removal from an off‐gas stream was performed in a spray column by H2S reactive absorption into a NaOH solution. The individual and interactive effects of three independent operating variables on the percentage of absorbed H2S were investigated: the initial pH of the scrubbing solution, the initial scrubbing solution temperature, and the volumetric liquid‐to‐gas ratio. The optimum operating variables were determined by response surface methodology (RSM) attaining a percentage of absorbed H2S of 98.7 ± 0.2 %. Additionally, the process performance was modeled by an artificial neural network (ANN) to predict the percentage of absorbed H2S. The results showed that the experimental data agreed better with the ANN model than with the RSM results.
New 3‐(Heteroaryl)‐2‐iminocoumarin‐based Borate Complexes: Synthesis, Photophysical Properties, and Rational Functionalization for Biosensing/Biolabeling Applications
Authors: Roubinet Benoît , Massif Cédrik , Moreau Mathieu , Boschetti Frédéric , Ulrich Gilles , Ziessel Raymond , Renard Pierre‐Yves , Romieu Anthony
Published: August 2015

Members of a series of boron difluoride complexes with 3‐(heteroaryl)‐2‐iminocoumarin ligands bearing both a phenolic hydroxyl group (acting as a fluorogenic center) and an N‐aryl substituent (acting as a stabilizing moiety) have been synthesized in good yields by applying a straightforward two‐step method. These novel fluorogenic dyes belong to the family of “Boricos” (D. Frath et al., Chem. Commun.­ 2013, 49, 4908–4910) and are the first examples of phenol‐based fluorophores of which the photophysical properties in the green‐yellow spectral range are dramatically improved by N,N‐chelation of a boron atom. Modulation of their fluorescence properties through reversible chemical modification of their phenol moieties has been demonstrated by the preparation of the corresponding 2,4‐dinitrophenyl (DNP) ethers, which led to a dramatic “OFF‐ON” fluorescence response upon reaction with thiols. Additionally, to expand the scope of these “7‐hydroxy‐Borico” derivatives, particularly in biolabeling, amine or carboxylic acid functionalities amenable to (bio)conjugation have been introduced within their scaffold. Their utility has been demonstrated in the preparation of fluorescent bovine serum albumin (BSA) conjugates and “Borico”‐DOTA‐like scaffolds in an effort to design novel monomolecular multimodal fluorescence‐ radioisotope imaging agents.
Steric Effects on the Structures, Reactivity, and Coordination Chemistry of Tris(2‐pyridyl)aluminates
Authors: García‐Rodríguez Raúl , Wright Dominic S.
Published: August 2015

Introducing substituents in the 6‐position of the 2‐pyridyl rings of tris(pyridyl)aluminate anions, of the type [EtAl(2‐py′)3]− (py′=a substituted 2‐pyridyl group), has a large impact on their metal coordination characteristics. This is seen most remarkably in the desolvation of the THF solvate [EtAl(6‐Me‐2‐py)3Li⋅THF] to give the monomer [EtAl(6‐Me‐2‐py)3Li] (1), containing a pyramidal, three‐coordinate Li+ cation. Similar monomeric complexes are observed for [EtAl(6‐CF3‐2‐py)3Li] (2) and [EtAl(6‐Br‐2‐py)3Li] (3), which contain CF3 and Br substituents (R). This steric influence can be exploited in the synthesis of a new class of terminal AlOH complexes, as is seen in the controlled hydrolysis of 2 and 3 to give [EtAl(OH)(6‐R‐2‐py)2]− anions, as in the dimer [EtAl(OH)(6‐Br‐2‐py)2Li]2 (5). Attempts to deprotonate the AlOH group of 5 using Et2Zn led only to the formation of the zincate complex [LiZn(6‐Br‐py)3]2 (6), while reactions of the 6‐Br substituted 3 and the unsubstituted complex [EtAl(2‐py)3Li] with MeOH give [EtAl(OMe)(6‐Br‐2‐py)2Li]2 (7) and [EtAl(OMe)(2‐py)2Li]2 (8), respectively, having similar dimeric arrangements to 5. The combined studies presented provide key synthetic methods for the functionalization and elaboration of tris(pyridyl)aluminate ligands.
Zähmodifizierte Duroplaste mittels Phasen‐kompatibilisierender, Aminoharz‐ummantelter Latex‐Partikel
Authors: Paulke Bernd‐Reiner , Börner Frank , Hahn Mathias , Jobmann Monika , Englich Sascha , Gehde Michael , Michael Hannes
Published: August 2015

Mit einer neuen Generation von Kern‐Schale‐Polymer‐Kompositen lassen sich die Eigenschaftsbilder von Elastomeren und von Thermoplasten miteinander kombinieren sowie Duroplaste zähmodifizieren. An Grenzflächen oder in Grenzschichten der Polymerstruktur positioniert, können Kern‐Schale‐Mikrokomposite schon bei relativ niedrigem Gehalt in der Matrix eine Vermittlerrolle zwischen zwei Phasen übernehmen und damit die Anwendungsparameter eines Polymertyps positiv verändern.