bluuebunny/crossref_metadata_2025 huggingface dataset:
Supramolecular control of liquid crystals by doping with halogen-bonding dyes
Authors: Vapaavuori Jaana , Siiskonen Antti , Dichiarante Valentina , Forni Alessandra , Saccone Marco , Pilati Tullio , Pellerin Christian , Shishido Atsushi , Metrangolo Pierangelo , Priimagi Arri
Published: August 2017

Halogen bonding between photoactive guest dopants and liquid-crystal host enhances the optical performance of doped liquid crystals.
Evaluation of different buffer materials for solar cells with wide-gap Cu2ZnGeSxSe4−x absorbers
Authors: Schnabel T. , Seboui M. , Bauer A. , Choubrac L. , Arzel L. , Harel S. , Barreau N. , Ahlswede E.
Published: August 2017

In this work kesterite-type Cu2ZnGeSxSe4−x (CZGSSe) absorbers were coated with four different buffer layer materials: CdS, In2S3, Zn(O,S) and CdIn2S4.
In vitro and in vivo investigation of chitosan–polylysine polymeric nanoparticles for ovalbumin and CpG co-delivery
Authors: Han Yunfei , Duan Qian , Li Yanhui , Tian Jian
Published: August 2017

A simple and powerful vaccine delivery system was developed by electrostatic binding of chitosan-based polycation methoxy poly(ethylene glycol)–chitosan–poly(l-lysine) (mPEG–CS–PLL) with ovalbumin (OVA) and cytosine–phosphate–guanine (CpG).
Synthesis and evaluation of the antitumor activity of highly functionalised pyridin-2-ones and pyrimidin-4-ones
Authors: Du Xuan-Xuan , Huang Rong , Yang Chang-Long , Lin Jun , Yan Sheng-Jiao
Published: August 2017

The methods for selective synthesis of two novel types of compounds including pyridin-2-ones 3 and pyrimidin-4-ones 4 were developed. The antitumor bioactivity screening showed that certain compounds had potent antitumor activity.
Single-walled carbon nanotubes as stabilizing agents in red phosphorus Li-ion battery anodes
Authors: Smajic Jasmin , Alazmi Amira , Patole Shashikant P. , Costa Pedro M. F. J.
Published: August 2017

Structural breakdown and capacity loss of a red phosphorus-based anode material for lithium-ion batteries have been considerably attenuated with the addition of single-walled carbon nanotubes.
Preparation of PEI/CS aerogel beads with a high density of reactive sites for efficient Cr(vi) sorption: batch and column studies
Authors: Li Ran , An Qing-Da , Xiao Zuo-Yi , Zhai Bin , Zhai Shang-Ru , Shi Zhan
Published: August 2017

PEI/CS aerogel beads with a high density of reactive amino groups, with the aim of efficient Cr(vi) removal from aqueous solutions under column conditions, were easily preparedviacombinational yet controllable sol–gel and freeze drying processes.
Sumalactones A–D, four new curvularin-type macrolides from a marine deep sea fungus Penicillium Sumatrense
Authors: Wu Yue-Hua , Zhang Zhi-Han , Zhong Yue , Huang Jun-Jun , Li Xiao-Xia , Jiang Jin-Yan , Deng Yin-Yue , Zhang Lian-Hui , He Fei
Published: August 2017

Four new curvularin-type macrolides were isolated from a marine fungus Penicillium Sumatrense and their absolute configurations were determined by CD spectra and modified Mosher's methods.
Tuning the electronic and magnetic properties of penta-graphene using a hydrogen atom: a theoretical study
Authors: Liu Lin-Lin , Wang Ying , Chen Chun-Ping , Yu Hong-Xia , Zhao Lu-Si , Wang Xiao-Chun
Published: August 2017

Through changing the adsorption configuration of the hydrogen atom, we can remarkably increase the magnetic moment of penta-graphene by 137 times.
Improving the rates of Pd-catalyzed reactions by exciting the surface plasmons of AuPd bimetallic nanotriangles
Authors: Gangishetty Mahesh K. , Fontes Adriana M. , Malta Marcos , Kelly Timothy L. , Scott Robert W. J.
Published: August 2017

Au@Pd nanotriangles are used to accelerate coupling and hydrogenation reactions by a plasmonic heating mechanism.
Organocatalytic asymmetric domino Michael/O-alkylation reaction for the construction of succinimide substituted 3(2H)-furanones catalyzed by quinine
Authors: Zhou Jing , Bai Lijuan , Liang Guojuan , Chen Yongjie , Gan Zongjie , Wang Wu , Zhou Hui , Yu Yu
Published: August 2017

Asymmetric domino reaction of maleimides with γ-halogenated-β-ketoesters catalyzed by quinine is developed to give succinimide substituted 3(2H)-furanones in good enantioselectivities.
A database assisted protein structure prediction method via a swarm intelligence algorithm
Authors: Gao Pengyue , Wang Sheng , Lv Jian , Wang Yanchao , Ma Yanming
Published: August 2017

A swarm-intelligence-based protein structure prediction method holds promise for narrowing the sequence-structure gap of proteins.
Vapor-assisted room temperature nanoimprinting-induced molecular alignment in patterned poly(3-hexylthiophene) nanogratings and its stability during thermal annealing
Authors: Wang Kaixuan , Li Xiaohui , Wang Chao , Qian Menxiang , Ding Guangzhu , Liu Jieping
Published: August 2017

Vapor-assisted room-temperature nanoimprinting-induced molecular alignment in patterned poly(3-hexylthiophene) nanogratings and its thermal stability.
Force percolation of contractile active gels
Authors: Alvarado José , Sheinman Michael , Sharma Abhinav , MacKintosh Fred C. , Koenderink Gijsje H.
Published: August 2017

Living systems provide a paradigmatic example of active soft matter.
Particle accumulation and depletion in a microfluidic Marangoni flow
Authors: Orlishausen M. , Butzhammer L. , Schlotbohm D. , Zapf D. , Köhler W.
Published: August 2017

Tracer particles in microfluidic Marangoni flows are redistributed by collisions with the meniscus and are trapped inside the vortex.
Pinning susceptibility: a novel method to study growth of amorphous order in glass-forming liquids
Authors: Das Rajsekhar , Chakrabarty Saurish , Karmakar Smarajit
Published: August 2017

We propose an experimentally realizable yet simple susceptibility to study the growth of amorphous order.
Interpenetrating polymer networks of liquid-crystalline azobenzene polymers and poly(dimethylsiloxane) as photomobile materials
Authors: Ube T. , Minagawa K. , Ikeda T.
Published: August 2017

Interpenetrating polymer networks composed of liquid-crystalline azobenzene polymers and poly(dimethylsiloxane) were prepared to enhance the performance of photomobile materials.
A surface-engineered tape-casting fabrication technique toward the commercialisation of freestanding carbon nanotube sheets
Authors: Susantyoko Rahmat Agung , Karam Zainab , Alkhoori Sara , Mustafa Ibrahim , Wu Chieh-Han , Almheiri Saif
Published: August 2017

Surface-engineered tape-casting (SETC) is a facile and scalable preparation method to fabricate freestanding, flexible and foldable MWCNT and MWCNT-composite sheets.
Graphene-based carbon coated tin oxide as a lithium ion battery anode material with high performance
Authors: Zhang Qiang , Gao Qiuming , Qian Weiwei , Zhang Hang , Tan Yanli , Tian Weiqian , Li Zeyu , Xiao Hong
Published: August 2017

A ternary rGO/PC/SnO2nanocomposite with carbon-coated SnO2homogeneously grown on the surface of rGO using glucose as the soft templating agent delivers an initial specific discharge capacity of 2238.2 mA h g−1and retains 1467.8 mA h g−1after 150 cycles at 0.1C (1C = 782 mA g−1). Even at 1C after 200 cycles, the specific capacity is 618.3 mA h g−1.
Few-layer graphene improves silicon performance in Li-ion battery anodes
Authors: Greco Eugenio , Nava Giorgio , Fathi Reza , Fumagalli Francesco , Del Rio-Castillo A. E. , Ansaldo Alberto , Monaco Simone , Bonaccorso Francesco , Pellegrini Vittorio , Di Fonzo F.
Published: August 2017

A Li-ion battery anode based on few-layer graphene flakes and ultra-small Si nanoparticles shows a remarkable stability during cycling (0.04% capacity fading per cycle). Our approach offers a viable approach to develop new generation Li-ion battery anodes.
N3/Al2O3 composite nanochannels: photoelectric and photoelectric-and-pH cooperatively controlled ion gating
Authors: Liu You , Kong Yan , Fan Xia , Zhai Jin , Jiang Lei
Published: August 2017

A biomimetic photoelectric or photoelectric-and-pH cooperatively controlled ionic gate was demonstrated based on N3 molecule functionalized bullet shaped Al2O3 nanochannels.
Birhodanines and their sulfur analogues for air-stable n-channel organic transistors
Authors: Iijima Kodai , Le Gal Yann , Higashino Toshiki , Lorcy Dominique , Mori Takehiko
Published: August 2017

Birhodanines and the sulfur analogues are excellent n-channel transistor materials with long-term air stability even in the evaporated films.
High performance, top-emitting, quantum dot light-emitting diodes with all solution-processed functional layers
Authors: Tang Zhaobing , Lin Jie , Wang Lishuang , Lv Ying , Hu Yongsheng , Fan Yi , Guo Xiaoyang , Zhao Jialong , Wang Yunjun , Liu Xingyuan
Published: August 2017

High performance top-emitting green quantum dot light-emitting diodes have been developed based on an all-solution process and with a bottom Al anode.
Identification of drivers for the metamorphic transition of HIV-1 reverse transcriptase
Authors: Zheng Xunhai , Mueller Geoffrey A. , Kim Kyungmin , Perera Lalith , DeRose Eugene F. , London Robert E.
Published: August 2017

Recent structural characterizations of the p51 and p66 monomers have established an important starting point for understanding the maturation pathway of the human immunodeficiency virus (HIV)-1 reverse transcriptase p66/p51 heterodimer. This process requires a metamorphic transition of the polymerase domain leading to formation of a p66/p66′ homodimer that exists as a structural heterodimer. To better understand the drivers for this metamorphic transition, we have performed NMR studies of 15N-labeled RT216 — a construct that includes the fingers and most of the palm domains. These studies are consistent with the conclusion that the p66 monomer exists as a spring-loaded complex. Initial dissociation of the fingers/palm : connection complex allows the fingers/palm to adopt an alternate, more stable structure, reducing the rate of reassociation and facilitating subsequent maturation steps. One of the drivers for an initial extension of the fingers/palm domains is identified as a straightening of helix E relative to its conformation in the monomer by eliminating a bend of ∼50° near residue Phe160. NMR and circular dichroism data also are consistent with the conclusion that a hydrophobic surface of palm domain that becomes exposed after the initial dissociation, as well as the intrinsic conformational preferences of the palm domain C-terminal segment, facilitates the formation of the β-sheet structure that is unique to the active polymerase subunit. Spectral comparisons based on 15N-labeled constructs are all consistent with previous structural conclusions based on studies of 13C-methyl-labeled constructs.
Analysis of Item-Level Bias in the Bayley-III Language Subscales: The Validity and Utility of Standardized Language Assessment in a Multilingual Setting
Authors: Goh Shaun K. Y. , Tham Elaine K. H. , Magiati Iliana , Sim Litwee , Sanmugam Shamini , Qiu Anqi , Daniel Mary L. , Broekman Birit F. P. , Rifkin-Graboi Anne
Published: August 2017

Purpose

The purpose of this study was to improve standardized language assessments among bilingual toddlers by investigating and removing the effects of bias due to unfamiliarity with cultural norms or a distributed language system.

Method

The Expressive and Receptive Bayley-III language scales were adapted for use in a multilingual country (Singapore). Differential item functioning (DIF) was applied to data from 459 two-year-olds without atypical language development. This involved investigating if the probability of success on each item varied according to language exposure while holding latent language ability, gender, and socioeconomic status constant. Associations with language, behavioral, and emotional problems were also examined.

Results

Five of 16 items showed DIF, 1 of which may be attributed to cultural bias and another to a distributed language system. The remaining 3 items favored toddlers with higher bilingual exposure. Removal of DIF items reduced associations between language scales and emotional and language problems, but improved the validity of the expressive scale from poor to good.

Conclusions

Our findings indicate the importance of considering cultural and distributed language bias in standardized language assessments. We discuss possible mechanisms influencing performance on items favoring bilingual exposure, including the potential role of inhibitory processing.
The completeness-corrected rate of stellar encounters with the Sun from the first Gaia data release
Authors: Bailer-Jones C. A. L.
Published: August 2017

I report on close encounters of stars to the Sun found in the first Gaia data release (GDR1). Combining Gaia astrometry with radial velocities of around 320 000 stars drawn from various catalogues, I integrate orbits in a Galactic potential to identify those stars which pass within a few parsecs. Such encounters could influence the solar system, for example through gravitational perturbations of the Oort cloud. 16 stars are found to come within 2 pc (although a few of these have dubious data). This is fewer than were found in a similar study based on Hipparcos data, even though the present study has many more candidates. This is partly because I reject stars with large radial velocity uncertainties (>10 km s-1), and partly because of missing stars in GDR1 (especially at the bright end). The closest encounter found is Gl 710, a K dwarf long-known to come close to the Sun in about 1.3 Myr. The Gaia astrometry predict a much closer passage than pre-Gaia estimates, however: just 16 000 AU (90% confidence interval: 10 000–21 000 AU), which will bring this star well within the Oort cloud. Using a simple model for the spatial, velocity, and luminosity distributions of stars, together with an approximation of the observational selection function, I model the incompleteness of this Gaia-based search as a function of the time and distance of closest approach. Applying this to a subset of the observed encounters (excluding duplicates and stars with implausibly large velocities), I estimate the rate of stellar encounters within 5 pc averaged over the past and future 5 Myr to be 545 ± 59 Myr-1. Assuming a quadratic scaling of the rate within some encounter distance (which my model predicts), this corresponds to 87 ± 9 Myr-1 within 2 pc. A more accurate analysis and assessment will be possible with future Gaia data releases.
Efforts Toward a Synthesis of Crotogoudin and Crotobarin
Authors: Mai Duy , Uchenik Dmitriy , Vanderwal Christopher
Published: August 2017

Two synthesis designs for the diterpenoid crotogoudin are discussed, and efforts to achieve each are described. First, a Cope rearrangement/intramolecular Diels–Alder cascade reaction was investigated. Second, a bioinspired sequence of cationic bicyclization and A-ring oxidative fragmentation set-up for a lactonization induced by a phenolic oxidation, ultimately providing a tricyclic intermediate that required only installation of the bridging ring of the salient bicyclo[2.2.2]octane system. This last endeavor was fraught with difficulty, but did lead to the development of conditions for cyclization of related keto-alkenes via manganese(III)-based radical chemistry.
Structure and magnetic properties of CuIn1-xTxTe2 (T=Co,Mn)
Authors: Guo Yongquan , Li Shuai , Wang Tai , Xie Nana
Published: August 2017

The crystal structures, magnetic and optical properties of the 3d transition metals of Co or Mn doped CuInTe2 have been investigated using X-ray diffraction, magnetic measurements, ultraviolet and visible spectrophotometers. It is found that CuIn1-xTxTe2 (T=Co, Mn) crystallize in tetragonal chalcopyrite structure in a doping range of x=0-0.2. The structural analyses show that the 3d transition metal of Mn or Co prefers to occupy the 4b crystal position. Mn-doped CuIn1-xMnxTe2 (x=0-0.3) show paramagnetic characteristics at room temperature with the susceptibilities of about 10-5. However, lightly Co-doping into CuIn1-xCoxTe2 shows ferromagnetism at room temperature under a low applied field. This phenomenon is suggested to result from the spin-spin interactions between Co atoms which lead to the ferromagnetism. CuIn0.9Co0.1Te2 with ferromagnetism at room temperature under a low field revealed in this work indicates that it a good candidate for photovoltaic cells application since its bandgap matches well with that of CuIn1-xGaxSe2 with high conversion efficiency.
Direct correlation between potentiometric and impedance biosensing of antibody-antigen interactions using an integrated system
Authors: Tsai Meng-Yen , Creedon Niamh , Brightbill Eleanor , Pavlidis Spyridon , Brown Billyde , Gray Darren W. , Shields Niall , Sayers Ríona , Mooney Mark H. , O'Riordan Alan , Vogel Eric M.
Published: August 2017

A fully integrated system that combines extended gate field-effect transistor (EGFET)-based potentiometric biosensors and electrochemical impedance spectroscopy (EIS)-based biosensors has been demonstrated. This integrated configuration enables the sequential measurement of the same immunological binding event on the same sensing surface and consequently sheds light on the fundamental origins of sensing signals produced by FET and EIS biosensors, as well as the correlation between the two. Detection of both the bovine serum albumin (BSA)/anti-BSA model system in buffer solution and bovine parainfluenza antibodies in complex blood plasma samples was demonstrated using the integrated biosensors. Comparison of the EGFET and EIS sensor responses reveals similar dynamic ranges, while equivalent circuit modeling of the EIS response shows that the commonly reported total impedance change (ΔZtotal) is dominated by the change in charge transfer resistance (Rct) rather than surface capacitance (Csurface). Using electrochemical kinetics and the Butler-Volmer equation, we unveil that the surface potential and charge transfer resistance, measured by potentiometric and impedance biosensors, respectively, are, in fact, intrinsically linked. This observation suggests that there is no significant gain in using the FET/EIS integrated system and leads to the demonstration that low-cost EGFET biosensors are sufficient as a detection tool to resolve the charge information of biomolecules for practical sensing applications.
Prescreening and efficiency in the evaluation of integrals over ab initio effective core potentials
Authors: Shaw Robert A. , Hill J. Grant
Published: August 2017

New, efficient schemes for the prescreening and evaluation of integrals over effective core potentials (ECPs) are presented. The screening is shown to give a rigorous, and close bound, to within on average 10% of the true value. A systematic rescaling procedure is given to reduce this error to approximately 0.1%. This is then used to devise a numerically stable recursive integration routine that avoids expensive quadratures. Tests with coupled clusters with single and double excitations and perturbative triple calculations on small silver clusters demonstrate that the new schemes show no loss in accuracy, while reducing both the power and prefactor of the scaling with system size. In particular, speedups of roughly 40 times can be achieved compared to quadrature-based methods.
On the feasibility of a pulsed gyrotron with a peak rf power exceeding the power of the operating electron beam
Authors: Glyavin M. Yu. , Osharin I. V. , Savilov A. V.
Published: August 2017

It is shown that at certain conditions, a two-wave regime of excitation of a gyrotron can be realized. A complicated transient process of excitation in this regime is characterized by sequential excitation of two modes with slightly different frequencies. This two-mode regime can be used for the formation of a short pulse of the output rf radiation with a peak power exceeding the power of the operating electron beam.
An argon ion beam milling process for native AlOx layers enabling coherent superconducting contacts
Authors: Grünhaupt Lukas , von Lüpke Uwe , Gusenkova Daria , Skacel Sebastian T. , Maleeva Nataliya , Schlör Steffen , Bilmes Alexander , Rotzinger Hannes , Ustinov Alexey V. , Weides Martin , Pop Ioan M.
Published: August 2017

We present an argon ion beam milling process to remove the native oxide layer forming on aluminum thin films due to their exposure to atmosphere in between lithographic steps. Our cleaning process is readily integrable with conventional fabrication of Josephson junction quantum circuits. From measurements of the internal quality factors of superconducting microwave resonators with and without contacts, we place an upper bound on the residual resistance of an ion beam milled contact of 50 mΩ μm2 at a frequency of 4.5 GHz. Resonators for which only 6% of the total foot-print was exposed to the ion beam milling, in areas of low electric and high magnetic fields, showed quality factors above 106 in the single photon regime, and no degradation compared to single layer samples. We believe these results will enable the development of increasingly complex superconducting circuits for quantum information processing.
Improvement of wettability and absorbancy of textile using atmospheric pressure dielectric barrier discharge
Authors: Ghimire Bhagirath , Subedi Deepak Prasad , Khanal Raju
Published: August 2017

In this study, cotton textile samples, commonly used in making quilt covers were subjected to atmospheric pressure dielectric barrier discharge treatment to study their surface wettability and absorbancy. Samples were treated in the discharge using a rotatory mechanism and the effects of plasma treatment were examined by contact angle measurement and weight measurement. Air plasma treatment was successful in incorporating hydrophilic functional groups on the textile surface due to which wettability as well as absorbancy immediately after the treatment were highly improved. Effects of plasma treatment started to appear only after 20 cycles (9 mins) and got saturated after 24 cycles (10.8 mins) of treatment. The contact angle reduced from 137 ° (untreated sample) to a value less than 30 ° while absorbancy increased by more than two times as compared to untreated sample. Also, the aging behavior of the plasma treated samples were studied for about a week after plasma treatment. It was observed that the induced oxygen containing groups re-oriented into the bulk of the material during their storage in the environment due to which initial properties of the samples recovered gradually. Our results indicate that low temperature plasma can be successfully applied to modify the properties of textiles and textile industries could utilize this by standardization.
Cluster analysis of accelerated molecular dynamics simulations: A case study of the decahedron to icosahedron transition in Pt nanoparticles
Authors: Huang Rao , Lo Li-Ta , Wen Yuhua , Voter Arthur F. , Perez Danny
Published: August 2017

Modern molecular-dynamics-based techniques are extremely powerful to investigate the dynamical evolution of materials. With the increase in sophistication of the simulation techniques and the ubiquity of massively parallel computing platforms, atomistic simulations now generate very large amounts of data, which have to be carefully analyzed in order to reveal key features of the underlying trajectories, including the nature and characteristics of the relevant reaction pathways. We show that clustering algorithms, such as the Perron Cluster Cluster Analysis, can provide reduced representations that greatly facilitate the interpretation of complex trajectories. To illustrate this point, clustering tools are used to identify the key kinetic steps in complex accelerated molecular dynamics trajectories exhibiting shape fluctuations in Pt nanoclusters. This analysis provides an easily interpretable coarse representation of the reaction pathways in terms of a handful of clusters, in contrast to the raw trajectory that contains thousands of unique states and tens of thousands of transitions.
A low-cost approach to electronic excitation energies based on the driven similarity renormalization group
Authors: Li Chenyang , Verma Prakash , Hannon Kevin P. , Evangelista Francesco A.
Published: August 2017

We propose an economical state-specific approach to evaluate electronic excitation energies based on the driven similarity renormalization group truncated to second order (DSRG-PT2). Starting from a closed-shell Hartree–Fock wave function, a model space is constructed that includes all single or single and double excitations within a given set of active orbitals. The resulting VCIS-DSRG-PT2 and VCISD-DSRG-PT2 methods are introduced and benchmarked on a set of 28 organic molecules [M. Schreiber et al., J. Chem. Phys. 128, 134110 (2008)]. Taking CC3 results as reference values, mean absolute deviations of 0.32 and 0.22 eV are observed for VCIS-DSRG-PT2 and VCISD-DSRG-PT2 excitation energies, respectively. Overall, VCIS-DSRG-PT2 yields results with accuracy comparable to those from time-dependent density functional theory using the B3LYP functional, while VCISD-DSRG-PT2 gives excitation energies comparable to those from equation-of-motion coupled cluster with singles and doubles.
Vortex-induced vibrations of three staggered circular cylinders at low Reynolds numbers
Authors: Behara Suresh , Ravikanth B. , Chandra Venu
Published: August 2017

Vortex-induced vibrations of three staggered circular cylinders are investigated via two-dimensional finite element computations. All the cylinders are of equal diameter (D) and are mounted on elastic supports in both streamwise (x−) and transverse (y−) directions. The two downstream cylinders are placed symmetrically on either side of the upstream body at a streamwise gap of 5D, with the vertical distance between them being 3D. Flow simulations are carried out for Reynolds numbers (Re) in the range of Re = 60-160. Reduced mass (m*) of 10 is considered and the damping is set to zero value. The present investigations show that the upstream cylinder exhibits initial and lower synchronization response modes like an isolated cylinder does at low Re. Whereas for both the downstream cylinders, the upper lock-in branch also appears. The initial and the upper modes are characterized by periodic oscillations, while the lower lock-in branch is associated with nonperiodic vibrations. The 2S mode of vortex shedding is observed in the near wake of all the cylinders for all Re, except for the upper branch corresponding to the downstream bodies. In the upper branch, both the downstream cylinders shed the primary vortices of the P+S mode. For the upstream cylinder, the phase between lift and the transverse displacement exhibits a 180° jump at certain Re in the lower branch. On the other hand, the downstream bodies undergo transverse oscillations in phase with lift in all lock-in modes, while the phase jumps by 180° as the oscillation response reaches the desynchronization regime.
Physical properties of nanometer graphene oxide films partially and fully reduced by annealing in ultra-high vacuum
Authors: Jernigan Glenn G. , Nolde Jill A. , Mahadik Nadeem A. , Cleveland Erin R. , Boercker Janice E. , Katz Michael B. , Robinson Jeremy T. , Aifer Edward H.
Published: August 2017

The properties of reduced graphene oxide (GO) are reported from a non-chemical reduction method. Ultra-high vacuum annealing of GO films in the thickness of 1–80 nm was studied by XPS, AFM, UV-Vis-NIR, Raman, and TEM to observe the controlled removal of oxygen. We observed the loss of hydroxyl (C-OH) at low temperatures (<600 °C) followed by the complete loss of carbonyls (C = O) and epoxy (C-O-C) species by 1200 °C. As oxygen was removed, we observed a decrease in the layer spacing between the GO sheets and a concurrent decrease in the film resistance. While the Raman spectroscopy showed no change with reduction, indicating no change in the overall defect density or the general structure of the GO, the transmission spectra showed a shift in the transmission minimum from 245 nm to 260 nm, and a total decrease in transmission above 800 nm occurs as the films visibly darken. TEM indicated that there is turbostratic stacking of the graphene layers as the reduction occurs, leading us to conclude that at a certain threshold of reduction the film properties are similar to epitaxial graphene growth on the C-face of SiC, but that a reduction gone too far results in a layer spacing equivalent to graphite.
On the limits of coercivity in permanent magnets
Authors: Fischbacher J. , Kovacs A. , Oezelt H. , Gusenbauer M. , Schrefl T. , Exl L. , Givord D. , Dempsey N. M. , Zimanyi G. , Winklhofer M. , Hrkac G. , Chantrell R. , Sakuma N. , Yano M. , Kato A. , Shoji T. , Manabe A.
Published: August 2017

The maximum coercivity that can be achieved for a given hard magnetic alloy is estimated by computing the energy barrier for the nucleation of a reversed domain in an idealized microstructure without any structural defects and without any soft magnetic secondary phases. For Sm1–zZrz(Fe1–yCoy)12–xTix based alloys, which are considered an alternative to Nd2Fe14B magnets with a lower rare-earth content, the coercive field of a small magnetic cube is reduced to 60% of the anisotropy field at room temperature and to 50% of the anisotropy field at elevated temperature (473 K). This decrease of the coercive field is caused by misorientation, demagnetizing fields, and thermal fluctuations.
Flexible silicon-based alpha-particle detector
Authors: Schuster C. S. , Smith B. R. , Sanderson B. J. , Mullins J. T. , Atkins J. , Joshi P. , McNamara L. , Krauss T. F. , Jenkins D. G.
Published: August 2017

The detection of alpha particles in the field can be challenging due to their short range in air of often only a few centimeters or less. This short range is a particular issue for measuring radiation inside contaminated pipework in the nuclear industry, for which there is currently no simple method available without cutting the pipes open. Here, we propose an approach for low cost, rapid, and safe identification of internally contaminated pipework based on a flexible 30 × 10 mm2 sheet of 50 μm thin crystalline silicon. Following established fabrication steps of pn-junction diodes, we have constructed a device with a signal-to-noise ratio of >20 in response to 5.5 MeV alpha-particles using a bespoke amplifier circuit. As flexible detectors may readily conform to a curved surface and are able to adapt to the curvature of a given pipeline, our prototype device stands out as a viable solution for nuclear decommissioning and related applications.
Negative tunneling magnetoresistance of Fe/MgO/NiO/Fe magnetic tunnel junction: Role of spin mixing and interface state
Authors: Zhang Y. , Yan X. H. , Guo Y. D. , Xiao Y.
Published: August 2017

Motivated by a recent tunneling magnetoresistance (TMR) measurement in which the negative TMR is observed in MgO/NiO-based magnetic tunnel junctions (MTJs), we have performed systematic calculations of transmission, current, and TMR of Fe/MgO/NiO/Fe MTJ with different thicknesses of NiO and MgO layers based on noncollinear density functional theory and non-equilibrium Green's function theory. The calculations show that, as the thickness of NiO and MgO layers is small, the negative TMR can be obtained which is attributed to the spin mixing effect and interface state. However, in the thick MTJ, the spin-flipping scattering becomes weaker, and thus, the MTJs recover positive TMR. Based on our theoretical results, we believe that the interface state at Fe/NiO interface and the spin mixing effect induced by noncollinear interfacial magnetization will play important role in determining transmission and current of Fe/MgO/NiO/Fe MTJ. The results reported here will be important in understanding the electron tunneling in MTJ with the barrier made by transition metal oxide.
Geography of intergenerational mobility and child development
Authors: Donnelly Louis , Garfinkel Irwin , Brooks-Gunn Jeanne , Wagner Brandon G. , James Sarah , McLanahan Sara
Published: August 2017

Significance

Using data from an urban birth cohort study, we show that children from low-income families who grow up in counties that produce high levels of upward mobility, as recently estimated by Chetty and Hendren, exhibit fewer externalizing behaviors by age 3 years and show substantial gains in cognitive test scores between ages 3 and 9 years. These associations are robust to controls for family characteristics, including parental intelligence, impulsivity, and mental health. This paper identifies developmental pathways through which intergenerational mobility of place, measured at the county level, shapes the economic prospects of children from low-income families.
A model explaining the matrilateral bias in alloparental investment
Authors: Perry Gretchen , Daly Martin
Published: August 2017

Significance

Parents raising children rely heavily on related helpers (“alloparents”), who are mainly the mother’s kin rather than the father’s. This “matrilateral bias” is cross-culturally ubiquitous and requires explanation. The dominant evolutionary view is that it serves as a defense against investing resources in unrelated children whose paternity has been misattributed. The evolutionary model proposed here includes paternity uncertainty as one component of the explanation, but adds additional elements derived from the insight that alloparenting constitutes an investment in the mother as well as in her children, raising her subsequent capacity to invest in other relatives. This model lays a foundation for future research on how the receipt of alloparental help changes the lives of mothers.
Friction law and hysteresis in granular materials
Authors: DeGiuli E. , Wyart M.
Published: August 2017

Significance

The macroscopic friction of particulate materials often weakens as flow rate is increased. This property is responsible for important intermittent phenomena in geophysics, including earthquakes and landslides. However, it is not understood even in simple granular materials, where it is responsible for hysteresis of the angle of repose. Here we argue that, for aerial granular flows, velocity weakening is an emergent collective property induced by endogenous mechanical noise. Our theory rationalizes previously unexplained observations, and generates experimentally testable predictions. At a microscopic level, it predicts that several microscopic quantities do not have a hard-particle limit, and characterizes their scaling behavior near jamming, which we confirm numerically.
Neoliberal democratisation, colonial legacies and the rise of the non-state provision of social welfare in West Africa
Authors: MacLean Lauren M.
Published: August 2017

This article explores the rise of the non-state provision of social welfare in West Africa. Over the past three decades, a range of non-state actors, including secular non-governmental organisations, faith-based organisations, for-profit businesses and informal networks have provided access to basic social services such as education and health care even more extensively than states. The article asks: why has the number of non-state providers increased so markedly across Africa, and why do the predominant types of non-state providers vary in different countries? The author argues that neoliberal democratisation during the 1980s and 1990s created new opportunities and spaces for non-state providers. Yet, an analysis of Ghana, Côte d’Ivoire and Liberia shows that colonial legacies have mediated the numbers and types of non-state actors on the ground. The conclusion highlights how this growth in non-state provision has significant negative consequences for citizens’ ability to obtain equitable access to and accountability for social welfare services.
Nasunin inhibits the lipopolysaccharide-induced pro-inflammatory mediator production in RAW264 mouse macrophages by suppressing ROS-mediated activation of PI3 K/Akt/NF-κB and p38 signaling pathways
Authors: Komatsu Wataru , Itoh Kazuko , Akutsu Satomi , Kishi Hisashi , Ohhira Shuji
Published: August 2017

Nasunin is a major anthocyanin in eggplant peel. The purpose of this study was to examine the anti-inflammatory effects of nasunin in lipopolysaccharide (LPS)-stimulated RAW264 macrophages and to identify the molecular mechanisms underlying these effects. We found that nasunin reduced the LPS-induced secretion of tumor necrosis factor-α, interleukin-6 and nitric oxide, and expression of inducible nitric oxide synthase in a dose-dependent manner. Nasunin diminished LPS-induced nuclear factor-κB (NF-κB) activation by suppressing the degradation of inhibitor of κB-α and nuclear translocation of p65 subunit of NF-κB. Nasunin also attenuated the phosphorylation of Akt and p38, signaling molecules involved in pro-inflammatory mediator production. Moreover, nasunin inhibited the intracellular accumulation of ROS, leading to the suppression of NF-κB activation, Akt and p38 phosphorylation, and subsequent pro-inflammatory mediator production. These findings suggest that nasunin exerts an anti-inflammatory effect and this effect is mediated, at least in part, by its antioxidant activity.
Centrosome signaling pathways consult on their decision
Authors: Short Ben
Published: August 2017

Study reveals unexpected dialog between mitotic entrance and exit pathway proteins on yeast spindle pole bodies.
Employing hole-array recess of barrier layer of AlGaN/GaN Heterostructures to reduce annealing Temperature of Ohmic contact
Authors: Han Kefeng
Published: August 2017

Ohmic contact to AlGaN/GaN heterostructures employing hole-array recess of barrier layer is conducted in this paper, in which an Ohmic contact resistance of 0.2 Ωmm with an annealing temperature of 800 °C with 15 nm deep holes recessed on the AlGaN layer before annealing is obtained. The annealing temperature and metal morphology post annealing is compared between Ohmic contacts with and without hole array recess. The annealing temperature required for the Ohmic contact with hole recess to achieve minimum ohmic contact resistance is 40 °C lower when compared to an ordinary Ohmic contact without hole array recess. Additionally metal morphology is significantly improved, such as the reduction of irregular metal particles and metal bumps forming in the annealing process, smaller alloying grains, perfectly straight metal edge and no educts existing at metal sidewalls are realized. The results demonstrated in this paper are beneficial to the performance, yield and reliability of relevant devices and circuits.
ncDR: a comprehensive resource of non-coding RNAs involved in drug resistance
Authors: Dai Enyu , Yang Feng , Wang Jing , Zhou Xu , Song Qian , An Weiwei , Wang Lihong , Jiang Wei
Published: August 2017

As a promising field of individualized therapy, non-coding RNA pharmacogenomics promotes the understanding of different individual responses to certain drugs and acts as a reasonable reference for clinical treatment. However, relevant information is scattered across the published literature, which is inconvenient for researchers to explore non-coding RNAs that are involved in drug resistance. To address this, we systemically identified validated and predicted drug resistance-associated microRNAs and long non-coding RNAs through manual curation and computational analysis. Subsequently, we constructed an omnibus repository named ncDR, which furnishes a user-friendly interface that allows for convenient browsing, visualization, querying and downloading of data. Given the rapidly increasing interest in precision medicine, ncDR will significantly improve our understanding of the roles of regulatory non-coding RNAs in drug resistance and has the potential to be a timely and valuable resource.

Availability and implementation

http://www.jianglab.cn/ncDR/

Supplementary information

Supplementary data are available at Bioinformatics online.
Intracranial Aneurysm Parameters for Predicting a Future Subarachnoid Hemorrhage: A Long-Term Follow-up Study
Authors: Juvela Seppo , Korja Miikka
Published: August 2017

BACKGROUND: Retrospective studies have suggested that aneurysm morphology is a risk factor for subarachnoid hemorrhage (SAH).

OBJECTIVE: To investigate whether various morphological indices of unruptured intracranial aneurysms (UIAs) predict a future rupture.

METHODS: A total of 142 patients with UIAs diagnosed between 1956 and 1978 were followed prospectively until SAH, death, or the last contact. Morphological UIA indices from standard angiographic projections were measured at baseline and adjusted in multivariable Cox proportional hazards regression analyses for established risk factors for SAH.

RESULTS: During a follow-up of 3064 person-years, 34 patients suffered from an aneurysm rupture. In multivariable analyses, aneurysm volume, volume-to-ostium area ratio, and the bottleneck factor separately as continuous variables predicted aneurysm rupture. All the morphological indices were higher (P < .01) after the rupture than before. In final multivariable analyses, current smoking (adjusted hazard ratio 2.50, 95% CI 1.03-6.10, P = .044), location in the anterior communicating artery (4.28, 1.38-13.28, P = .012), age (inversely; 0.95 per year, 0.91-1.00, P = .043), and UIA diameter ≥7 mm at baseline (2.68, 1.16-6.21, P = .021) were independent risk factors for a future rupture. Aneurysm growth during the follow-up was associated with smoking (P < .05) and SAH (P < .001), but not with the aneurysm indices.

CONCLUSION: Of the morphological indices, UIA volume seems to predict a future rupture. However, as volume correlates with the maximum diameter of the aneurysm, it seems to add little to the predictive value of the maximum diameter. Retrospective studies using indices that are measured after rupture are of little value in risk prediction.
Prevalence of Carbapenem-Resistant Gram-Negative Infections in the United States Predominated by Acinetobacter baumannii and Pseudomonas aeruginosa
Authors: Cai Bin , Echols Roger , Magee Glenn , Arjona Ferreira Juan Camilo , Morgan Gareth , Ariyasu Mari , Sawada Takuko , Nagata Tsutae “Den”
Published: August 2017

Background

Carbapenem-resistant (CR) Gram-negative pathogens are recognized as a major health concern. This study examined the prevalence of infections due to 4 CR Gram-negative species (Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli) in the United States and assessed their impact on hospital stays and mortality.

Methods

Hospitalized patients with laboratory-confirmed infection due to any of the 4 Gram-negative pathogens were identified from the Premier Healthcare Database. Proportions of CR were calculated by pathogen and infection site (blood, respiratory, urinary, or other) for the United States as whole and by census regions. Crude and adjusted odds ratios for in-hospital mortality were produced using logistic regression.

Results

From 2009 to 2013, 13 262 (4.5%) of 292 742 infections due to these 4 Gram-negative pathogens were CR. Of these CR infections, 82.3% were caused by A. baumannii (22%) or P. aeruginosa (60.3%), while 17.7% were caused by K. pneumoniae or E. coli. CR patients had longer hospital stays than carbapenem-susceptible (CS) patients in all pathogen-infection site cohorts, except in the A. baumannii-respiratory cohort. The crude all cause in-hospital mortality was greater for most pathogen-infection site cohorts of the CR group compared with the CS group, especially for A. baumannii infection in the blood (crude odds ratio [OR], 3.91; 95% confidence interval [CI], 2.69–5.70). This difference for the A. baumannii-blood cohort remained after adjusting for the relevant covariates (adjusted OR, 2.46; 95% CI, 1.43–4.22).

Conclusion

The majority of CR infections and disease burden in the United States was caused by nonfermenters A. baumannii and P. aeruginosa. Patients with CR infections had longer hospital stays and higher crude in-hospital mortality.
Genetic and Molecular Characterization of Leaf Rust Resistance in Two Durum Wheat Landraces
Authors: Qureshi Naeela , Bariana Harbans , Kolmer James A. , Miah Hanif , Bansal Urmil
Published: August 2017

Leaf rust, caused by Puccinia triticina, is a constraint to durum wheat (Triticum turgidum subsp. durum) production, and landraces are reported to be an important source of resistance. Two Portuguese landraces (Aus26582 and Aus26579) showed resistance against durum-specific P. triticina races and were crossed with a susceptible landrace (Bansi) to develop recombinant inbred line (RIL) populations. Monogenic segregation for leaf rust resistance was observed among both RIL populations. The underlying locus, temporarily named LrAW2, was mapped to the short arm of chromosome 6B in the Aus26582/Bansi population and five DArTseq markers cosegregated with LrAW2. Simple sequence repeat markers sun683 and sun684, developed from the chromosome survey sequence (CSS) contig 6BS_2963854, identified through BlastN search of cosegregating DArTseq markers in the International Wheat Genome Sequencing Consortium database, cosegregated with LrAW2. Comparison of the CSS contig 6BS_2963854-based sequences amplified from parental genotypes led to the development of marker sunKASP_60, which also showed close linkage with LrAW2. Markers sun684 and sunKASP_60 showed close association with LrAW2 in both RIL populations. The amplification of LrAW2-specific products by linked markers in Aus26582, Aus26579, and Guayacan (Lr61) indicated that LrAW2 may be Lr61. The alternate amplicon or haplotype produced with LrAW2-linked markers in Australian durum cultivars demonstrated their effectiveness in marker-assisted selection.
Class-Wide Access to a Commercial Step 1 Question Bank During Preclinical Organ-Based Modules: A Pilot Project
Authors: Baños James H. , Pepin Mark E. , Van Wagoner Nicholas
Published: August 2017

Purpose

The authors examined the usefulness of a commercially available Step 1 question bank as a formative academic support tool throughout organ-based modules in an integrated preclinical medical curriculum. The authors also determined the extent to which correlation between question bank utilization and academic metrics varied with Medical College Admission Test (MCAT) scores.

Method

In 2015, a cohort of 185 first-year medical students at University of Alabama School of Medicine were provided with 18-month full access to a commercially available Step 1 question bank of over 2,100 items throughout organ-based modules, although there were no requirements for use. Data on student use of the question bank were collected via an online administrative portal. Relationships between question bank utilization and academic outcomes including exams, module grades, and United States Medical Licensing Examination (USMLE) Step 1 were determined using multiple linear regression.

Results

MCAT scores and number of items attempted in the question bank significantly predicted all academic measures, with question bank utilization as the stronger predictor. The association between question bank utilization and academic outcome was stronger for individuals with lower MCAT scores.

Conclusions

The findings elucidate a novel academic support mechanism that, for some programs, may help bridge the gap between holistic and mission-based admissions practices and a residency match process that places a premium on USMLE exam scores. Distributed formative use of USMLE Step 1 practice questions may be of value as an academic support tool that benefits all students, but particularly those entering with lower MCAT scores.