bluuebunny/crossref_metadata_2025 huggingface dataset:
Variant fatty acid-like molecules Conjugation, novel approaches for extending the stability of therapeutic peptides
Authors: Li Ying , Wang Yuli , Wei Qunchao , Zheng Xuemin , Tang Lida , Kong Dexin , Gong Min
Published: December 2015

The multiple physiological properties of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of type 2 diabetes. However, the in vivo half-life of GLP-1 is short due to rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. The poor stability of GLP-1 has significantly limited its clinical utility; however, many studies are focused on extending its stability. Fatty acid conjugation is a traditional approach for extending the stability of therapeutic peptides because of the high binding affinity of human serum albumin for fatty acids. However, the conjugate requires a complex synthetic approach, usually involving Lys and occasionally involving a linker. In the current study, we conjugated the GLP-1 molecule with fatty acid derivatives to simplify the synthesis steps. Human serum albumin binding assays indicated that the retained carboxyl groups of the fatty acids helped maintain a tight affinity to HSA. The conjugation of fatty acid-like molecules improved the stability and increased the binding affinity of GLP-1 to HSA. The use of fatty acid-like molecules as conjugating components allowed variant conjugation positions and freed carboxyl groups for other potential uses. This may be a novel, long-acting strategy for the development of therapeutic peptides.
One-step Synthesis of Few-layer WS2 by Pulsed Laser Deposition
Authors: Loh Tamie A. J. , Chua Daniel H. C. , Wee Andrew T. S.
Published: December 2015

Atomically thin tungsten disulfide (WS2) has attracted much attention in recent years due its indirect-to-direct band gap transition, band gap tunability and giant spin splitting. However, the fabrication of atomically thin WS2 remains largely underdeveloped in comparison to its structural analogue MoS2. Here we report the direct fabrication of highly crystalline few-layer WS2 on silver substrates by pulse laser deposition at the relatively low temperature of 450 °C. The growth takes places by conventional epitaxy, through the in-situ formation of nearly lattice-matching Ag2S on the silver surface. Intriguingly, it was observed that the resulting film was composed of not only the usual semiconducting 2H-WS2 structure but also the less common metallic 1T-WS2. Modifications of the synthesis parameters allow for control over the crystalline quality, film thickness and crystal phase composition of the resulting WS2 film.
pH-Triggered Molecular Alignment for Reproducible SERS Detection via an AuNP/Nanocellulose Platform
Authors: Wei Haoran , Vikesland Peter J.
Published: December 2015

The low affinity of neutral and hydrophobic molecules towards noble metal surfaces hinders their detection by surface-enhanced Raman spectroscopy (SERS). Herein, we present a method to enhance gold nanoparticle (AuNP) surface affinity by lowering the suspension pH below the analyte pKa. We developed an AuNP/bacterial cellulose (BC) nanocomposite platform and applied it to two common pollutants, carbamazepine (CBZ) and atrazine (ATZ) with pKa values of 2.3 and 1.7, respectively. Simple mixing of the analytes with AuNP/BC at pH < pKa resulted in consistent electrostatic alignment of the CBZ and ATZ molecules across the nanocomposite and highly reproducible SERS spectra. Limits of detection of 3 nM and 11 nM for CBZ and ATZ, respectively, were attained. Tests with additional analytes (melamine, 2,4-dichloroaniline, 4-chloroaniline, 3-bromoaniline and 3-nitroaniline) further illustrate that the AuNP/BC platform provides reproducible analyte detection and quantification while avoiding the uncontrolled aggregation and flocculation of AuNPs that often hinder low pH detection.
A dual role of transient receptor potential melastatin 2 channel in cytotoxicity induced by silica nanoparticles
Authors: Yu Peilin , Li Jin , Jiang Jialin , Zhao Zunquan , Hui Zhaoyuan , Zhang Jun , Zheng Yifan , Ling Daishun , Wang Lie , Jiang Lin-Hua , Luo Jianhong , Zhu Xinqiang , Yang Wei
Published: December 2015

Silica nanoparticles (NPs) have remarkable applications. However, accumulating evidence suggests NPs can cause cellular toxicity by inducing ROS production and increasing intracellular Ca2+ ([Ca2+]i), but the underlying molecular mechanism is largely unknown. Transient receptor potential melastatin 2 (TRPM2) channel is known to be a cellular redox potential sensor that provides an important pathway for increasing the [Ca2+]i under oxidative stress. In this study, we examined the role of TRPM2 channel in silica NPs-induced oxidative stress and cell death. By quantitation of cell viability, ROS production, [Ca2+]i and protein identification, we showed that TRPM2 channel is required for ROS production and Ca2+ increase induced by silica NPs through regulating NADPH oxidase activity in HEK293 cells. Strikingly, HEK293 cells expressing low levels of TRPM2 were more susceptible to silica NPs than those expressing high levels of TRPM2. Macrophages from young mice showed significantly lower TRPM2 expression than those from senescent mice and had significantly lower viability after silica NPs exposure than those from senescent ones. Taken together, these findings demonstrate for the first time that TRPM2 channel acts as an oxidative stress sensor that plays a dual role in silica NPs-induced cytotoxicity by differentially regulating the NADPH oxidase activity and ROS generation.
A random interacting network model for complex networks
Authors: Goswami Bedartha , Shekatkar Snehal M. , Rheinwalt Aljoscha , Ambika G. , Kurths Jürgen
Published: December 2015

We propose a RAndom Interacting Network (RAIN) model to study the interactions between a pair of complex networks. The model involves two major steps: (i) the selection of a pair of nodes, one from each network, based on intra-network node-based characteristics and (ii) the placement of a link between selected nodes based on the similarity of their relative importance in their respective networks. Node selection is based on a selection fitness function and node linkage is based on a linkage probability defined on the linkage scores of nodes. The model allows us to relate within-network characteristics to between-network structure. We apply the model to the interaction between the USA and Schengen airline transportation networks (ATNs). Our results indicate that two mechanisms: degree-based preferential node selection and degree-assortative link placement are necessary to replicate the observed inter-network degree distributions as well as the observed inter-network assortativity. The RAIN model offers the possibility to test multiple hypotheses regarding the mechanisms underlying network interactions. It can also incorporate complex interaction topologies. Furthermore, the framework of the RAIN model is general and can be potentially adapted to various real-world complex systems.
Zeolitic imidazole framework templated synthesis of nanoporous carbon as a novel fiber coating for solid-phase microextraction
Authors: Zhang Shuaihua , Yang Qian , Li Zhi , Wang Wenchang , Wang Chun , Wang Zhi
Published: December 2015

A novel ZIF templated nanoporous carbon was prepared as the SPME fiber coating for the extraction of organochlorine pesticides from vegetable samples.
Green and rapid synthesis of a water-dispersible Pt–reduced graphene oxide hybrid material for hydrogen peroxide detection
Authors: Lu Juanjuan , Liu Xiuhui , Zhang Yanjun , Liu Yidan , Li Ming , Lu Xiaoquan
Published: December 2015

A kind of water-dispersible Pt nanoparticle–reduced graphene oxide hybrid material (Pt–rGO) has been prepared by in situ reduction of both graphene oxide (GO) and the Pt precursor in acidic solution using metallic Zn powder.
Cyclic single-molecule magnets: from the odd-numbered heptanuclear to a dimer of heptanuclear dysprosium clusters
Authors: Tian Haiquan , Bao Song-Song , Zheng Li-Min
Published: December 2015

A heptanuclear compound and a dimer of heptanuclear dysprosium clusters (Dy7 and Dy14) have been successfully synthesized, which feature the largest odd-numbered cyclic lanthanide clusters reported thus far. Both exhibit single molecule magnet behaviours at low temperature.
Making C–H bonds with CO2: production of formate by molecular electrocatalysts
Authors: Taheri Atefeh , Berben Louise A.
Published: December 2015

This article reviews the progress in the reduction of CO2 to formate using molecular inorganic electrocatalysts, with an emphasis on recent insights and successes in selective C–H bond formation with CO2 to favor formate production in aqueous solutions.
The moisture-triggered controlled release of a natural food preservative from a microporous metal–organic framework
Authors: Wang Hao , Lashkari Elham , Lim Hyuna , Zheng Chong , Emge Thomas J. , Gong Qihan , Yam Kit , Li Jing
Published: December 2015

In this work we demonstrate that allyl isothiocyanate (AITC), a common food flavoring agent and food preservative, can be effectively captured by and released in a controlled manner from a microporous metal–organic framework (MOF).
Selective reduction of carbon dioxide to bis(silyl)acetal catalyzed by a PBP-supported nickel complex
Authors: Ríos Pablo , Curado Natalia , López-Serrano Joaquín , Rodríguez Amor
Published: December 2015

The selective reduction of CO2 to the formaldehyde level remains an important challenge and to date only a few catalysts have been developed for this reaction.
Exploiting hydrophobic borohydride-rich ionic liquids as faster-igniting rocket fuels
Authors: Liu Tianlin , Qi Xiujuan , Huang Shi , Jiang Linhai , Li Jianling , Tang Chenglong , Zhang Qinghua
Published: December 2015

A new family of hypergolic ionic liquids with ultra-short ignition delay times was designed and synthesized as potential rocket fuels.
Ionic liquid tethered post functionalized ZIF-90 framework for the cycloaddition of propylene oxide and CO2
Authors: Tharun Jose , Bhin Kyung-Mi , Roshan Roshith , Kim Dong Woo , Kathalikkattil Amal Cherian , Babu Robin , Ahn Hye Young , Won Yong Sun , Park Dae-Won
Published: December 2015

Covalent post functionalized ZIF-90 with pyridinium based ionic liquid was prepared and used as catalyst for the solventless synthesis of propylene carbonate.
Use of protein-engineered fabrics to identify design rules for integrin ligand clustering in biomaterials
Authors: Benitez Patrick L. , Mascharak Shamik , Proctor Amy C. , Heilshorn Sarah C.
Published: December 2015

We engineered novel electrospun protein fabrics to gain insight into cellular responses to heterogeneity in globalversuslocal ligand density.
Forward electrohydrodynamic inkjet printing of optical microlenses on microfluidic devices
Authors: Vespini V. , Coppola S. , Todino M. , Paturzo M. , Bianco V. , Grilli S. , Ferraro P.
Published: December 2015

We report a novel method for direct ink-jet printing of viscous polymers based on a pyro-electrohydrodynamic repulsion system capable of overcoming limitations of previous classical EHD ink-jet printing on the material type, geometry and thickness of the receiving substrate.
Dehydration of AlPO4-34 studied by variable-temperature NMR, XRD and first-principles calculations
Authors: Varlec Jure , Krajnc Andraž , Mazaj Matjaž , Ristić Alenka , Vanatalu Kalju , Oss Andres , Samoson Ago , Kaučič Venčeslav , Mali Gregor
Published: December 2015

Complementary techniques elucidate water–framework interactions in different states of dehydration, two of which have not been observed before.
Immune response to functionalized mesoporous silica nanoparticles for targeted drug delivery
Authors: Heidegger Simon , Gößl Dorothée , Schmidt Alexandra , Niedermayer Stefan , Argyo Christian , Endres Stefan , Bein Thomas , Bourquin Carole
Published: December 2015

Mesoporous silica nanoparticles represent an efficient drug delivery vehicle to primary immune cells that is both non-toxic and non-inflammagenic.
Synthesis, crystal and electronic structure, and optical properties of two new chalcogenide-iodides: Ba3Q4I2 (Q = S, Se)
Authors: Wang Jian , Lee Kathleen , Kovnir Kirill
Published: December 2015

Two new ternary chalcogenide-iodides, Ba3S4I2 and Ba3Se4I2, exhibit both covalent and ionic chemical bonding.
One-dimensional nanofiber architecture of an anatase TiO2–carbon composite with improved sodium storage performance
Authors: Jung Kyu-Nam , Seong Ji-Young , Kim Sung-Soo , Lee Gyoung-Ja , Lee Jong-Won
Published: December 2015

One-dimensional TiO2–carbon nanofibers fabricatedviaan electrospinning technique exhibit superior sodium storage capability as an anode for sodium-ion batteries.
High birefringence bistolane liquid crystals: synthesis and properties
Authors: Węgłowska Dorota , Kula Przemysław , Herman Jakub
Published: December 2015

Twenty both symmetrical and non-symmetrical bistolanes with terminal alkyl, alkoxy and alkylsulfanyl chain and lateral methyl or ethyl group have been synthesized via Sonogashira cross-coupling and their mesomorphic properties have been studied.
Structural, optical and special spectral changes of Dy3+ emissions in orthovanadates
Authors: Kumari Puja , Manam J.
Published: December 2015

This paper reports on the structural, optical and photometric characterization of yttrium gadolinium orthovanadates (Y1−xGdxVO4) doped with Dy3+ for white emission in solid state lighting.
Synthesis of a novel micro/mesoporous composite material Beta-FDU-12 and its hydro-upgrading performance for FCC gasoline
Authors: Du Peng , Zheng Peng , Song Shaotong , Wang Xilong , Zhang Minghui , Chi Kebin , Xu Chunming , Duan Aijun , Zhao Zhen
Published: December 2015

A micro/mesoporous material Beta-FDU-12 was successfully synthesized. The material was used as a support additive and the corresponding catalyst CoMo/BFA was post-treated with EDTA. The catalyst CoMoE/BFA exhibited excellent hydro-upgrading performance for FCC gasoline.
Fundamentals of mass transfer and kinetics for biosorption of oil and grease from agro-food industrial effluent by Serratia marcescens SA30
Authors: Fulazzaky Mohamad Ali , Abdullah Shakila , Salim Mohd Razman
Published: December 2015

Biosorption mechanisms of oil and grease removal bySerratia marcescensSA30 from agro-food industrial effluent, attached on the oil palm frond.
Mixed ionic liquid/organic carbonate electrolytes for LiNi0.8Co0.15Al0.05O2 electrodes at various temperatures
Authors: Patra Jagabandhu , Wang Chueh-Han , Lee Tai-Chou , Wongittharom Nithinai , Lin Yi-Chuan , Ting-Kuo Fey George , Majumder S. B. , Hsieh Chien-Te , Chang Jeng-Kuei
Published: December 2015

At various temperatuers, different IL ratios in mixed electrolytes should be adopted to optimize cell relaibility and charge–discharge performance.
A facile and green strategy for the synthesis of 1-dimensional luminescent ZnO nanorods and their reduction behavior for aromatic nitro-compounds
Authors: Bhattacharjee Archita , Ahmaruzzaman M.
Published: December 2015

This article illustrates a facile microwave assisted synthesis of 1D ZnO nanorods using lauric acid.
Sensing and discrimination of cyanide and hydrogen sulfide using an 8-alkenyl-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene derivative
Authors: Alvarado-Martínez E. , Costero A. M. , Gil S. , Peña-Cabrera E.
Published: December 2015

8-(2-Phenylethenyl)BODIPY has been shown to be an appropriate chromo-fluorogenic probe for cyanide in H2O.
Correction: Preclinical appraisal of terbutaline analogues in precipitation of autism spectrum disorder
Authors: Sharma Neha , Gautam Swetlana , Devi Uma , Singh Manjari , Rawat Jitendra K. , Sethi Nikunj , Saraf Shubhini A. , Kaithwas Gaurav
Published: December 2015

Correction for ‘Preclinical appraisal of terbutaline analogues in precipitation of autism spectrum disorder’ by Neha Sharma et al., RSC Adv., 2015, 5, 39003–39011.
Self-cleaning MOF: realization of extreme water repellence in coordination driven self-assembled nanostructures
Authors: Roy Syamantak , Suresh Venkata M. , Maji Tapas Kumar
Published: December 2015

A superhydrophobic self-cleaning MOF nanostructure has been synthesized using a unique ligand design strategy and coordination directed self-assembly. The material has hierarchical surface roughness and is stable under extreme corrosive conditions.
Correction: Base pairing involving artificial bases in vitro and in vivo
Authors: Bande Omprakash , Braddick Darren , Agnello Stefano , Jang Miyeon , Pezo Valérie , Schepers Guy , Rozenski Jef , Lescrinier Eveline , Marlière Philippe , Herdewijn Piet
Published: December 2015

Correction for ‘Base pairing involving artificial bases in vitro and in vivo’ by Omprakash Bande et al., Chem. Sci., 2016, DOI: 10.1039/c5sc03474d.
A self-healing, re-moldable and biocompatible crosslinked polysiloxane elastomer
Authors: Zhao Jian , Xu Rui , Luo Gaoxing , Wu Jun , Xia Hesheng
Published: December 2015

The self-healable polysiloxane elastomers cross-linked with DA bonds show high healing efficiency, good mechanical properties and good biocompatibility.
Materials genomics of thin film strain relaxation by misfit dislocations
Authors: Hull R. , Parvaneh H. , Andersen D. , Bean John C.
Published: December 2015

We summarize the development and implementation of a “process simulator” for modeling thin film strain relaxation by injection of misfit dislocations. The process simulator, initially developed for GexSi1−x/Si(100) lattice-mismatched epitaxy, integrates elasticity and dislocation theory with experimental measurements of kinetic parameters describing dislocation nucleation, propagation, and interactions. This enables predictive simulation of the development of misfit dislocation arrays during growth and thermal annealing sequences. Further, in the spirit of the materials genome initiative, we show how once a relatively complete description is built for one materials system, extension to a related system may be implemented using a greatly reduced data set. We illustrate this concept by translation of the simulator for GexSi1−x/Si(100) epitaxy into predictive simulation for the GexSi1−x/Si(110) system (which has quite different dislocation microstructure and kinetics) using greatly reduced data sets for the latter system and incorporating data refinement methods to extract unknown kinetic parameters. This sets the platform for extension of these methods to a broader set of strained layer systems.
Note: Boundary homogenization for a circle with periodic absorbing arcs. Exact expression for the effective trapping rate
Authors: Skvortsov Alexei T. , Berezhkovskii Alexander M. , Dagdug Leonardo
Published: December 2015

This study deals with trapping of particles diffusing on a flat surface by a circle whose boundary contains identical, evenly spaced absorbing arcs separated by reflecting arcs. This means that the particle concentration on the circle satisfies heterogeneous boundary conditions which make the trapping problem rather complicated for analytical treatment. Boundary homogenization discussed in this note allows to bypass this difficulty by the approximate replacement of heterogeneous boundary conditions on the circle by an effective homogeneous one with a properly chosen effective trapping rate. We obtain a formula which gives this rate in terms of the circle radius, number of absorbing arcs, the fraction of the circle boundary occupied by the arcs, and the particle diffusivity.
Coherent vertical electron transport and interface roughness effects in AlGaN/GaN intersubband devices
Authors: Grier A. , Valavanis A. , Edmunds C. , Shao J. , Cooper J. D. , Gardner G. , Manfra M. J. , Malis O. , Indjin D. , Ikonić Z. , Harrison P.
Published: December 2015

We investigate electron transport in epitaxially grown nitride-based resonant tunneling diodes (RTDs) and superlattice sequential tunneling devices. A density-matrix model is developed, and shown to reproduce the experimentally measured features of the current–voltage curves, with its dephasing terms calculated from semi-classical scattering rates. Lifetime broadening effects are shown to have a significant influence in the experimental data. Additionally, it is shown that the interface roughness geometry has a large effect on current magnitude, peak-to-valley ratios and misalignment features; in some cases eliminating negative differential resistance entirely in RTDs. Sequential tunneling device characteristics are dominated by a parasitic current that is most likely to be caused by dislocations; however, excellent agreement between the simulated and experimentally measured tunneling current magnitude and alignment bias is demonstrated. This analysis of the effects of scattering lifetimes, contact doping and growth quality on electron transport highlights critical optimization parameters for the development of III–nitride unipolar electronic and optoelectronic devices.
Real-time dynamic calibration of a tunable frequency laser source using a Fabry-Pérot interferometer
Authors: Mandula Gábor , Kis Zsolt , Lengyel Krisztián
Published: December 2015

We report on a method for real-time dynamic calibration of a tunable external cavity diode laser by using a partially mode-matched plano-concave Fabry-Pérot interferometer in reflection geometry. Wide range laser frequency scanning is carried out by piezo-driven tilting of a diffractive grating playing the role of a frequency selective mirror in the laser cavity. The grating tilting system has a considerable mechanical inertness, so static laser frequency calibration leads to false results. The proposed real-time dynamic calibration based on the identification of primary- and Gouy-effect type secondary interference peaks with known frequency and temporal history can be used for a wide scanning range (from 0.2 GHz to more than 1 GHz). A concave spherical mirror with a radius of R = 100 cm and a plain 1% transmitting mirror was used as a Fabry-Pérot interferometer with various resonator lengths to investigate and demonstrate real-time calibration procedures for two kinds of laser frequency scanning functions.
Study on a discal TEM-TE11 mode converter loaded high-efficiency magnetically insulated transmission line oscillator
Authors: Zhang Xiaoping , Yuan Chengwei , Li Yangmei , Zhang Jiande , Zhang Qiang
Published: December 2015

An integrative high power microwave device is proposed, which consists of a high-efficiency L-band Magnetically Insulated Transmission Line Oscillator (MILO) and a discal TEM–TE11 mode converter. The MILO with a shrunken load composed of a step-like cathode and a ladder-like beam collector can generate a 1.58 GHz, 5.7 GW microwave with the efficiency of 20.8% at the diode voltage of 560 kV in simulation. The discal converter utilizes a pair of sectorial two-double radial waveguides and a pair of sectorial cross section waveguides to adjust the phase-difference and realizes the mode conversion in a length of less than half wavelength at 1.58 GHz. In the preliminary experiment, the proposed device generates over 2 GW, 1.575 GHz microwave with the pulse duration of over 50 ns in a 420 kV diode voltage; the corresponding efficiency is 14.9%; the radiation pattern is the ideal TE11 mode.
Extracting enzyme processivity from kinetic assays
Authors: Barel Itay , Reich Norbert O. , Brown Frank L. H.
Published: December 2015

A steady-state analysis for the catalytic turnover of molecules containing two substrate sites is presented. A broad class of Markovian dynamic models, motivated by the action of DNA modifying enzymes and the rich variety of translocation mechanisms associated with these systems (e.g., sliding, hopping, intersegmental transfer, etc.), is considered. The modeling suggests an elementary and general method of data analysis, which enables the extraction of the enzyme’s processivity directly and unambiguously from experimental data. This analysis is not limited to the initial velocity regime. The predictions are validated both against detailed numerical models and by revisiting published experimental data for EcoRI endonuclease acting on DNA.
Dual reorientation relaxation routes of water molecules in oxyanion’s hydration shell: A molecular geometry perspective
Authors: Xie Wen Jun , Yang Yi Isaac , Gao Yi Qin
Published: December 2015

In this study, we examine how complex ions such as oxyanions influence the dynamic properties of water and whether differences exist between simple halide anions and oxyanions. Nitrate anion is taken as an example to investigate the hydration properties of oxyanions. Reorientation relaxation of its hydration water can occur through two different routes: water can either break its hydrogen bond with the nitrate to form one with another water or switch between two oxygen atoms of the same nitrate. The latter molecular mechanism increases the residence time of oxyanion’s hydration water and thus nitrate anion slows down the translational motion of neighbouring water. But it is also a “structure breaker” in that it accelerates the reorientation relaxation of hydration water. Such a result illustrates that differences do exist between the hydration of oxyanions and simple halide anions as a result of different molecular geometries. Furthermore, the rotation of the nitrate solute is coupled with the hydrogen bond rearrangement of its hydration water. The nitrate anion can either tilt along the axis perpendicularly to the plane or rotate in the plane. We find that the two reorientation relaxation routes of the hydration water lead to different relaxation dynamics in each of the two above movements of the nitrate solute. The current study suggests that molecular geometry could play an important role in solute hydration and dynamics.
Generation of ultra-fast cumulative water jets by sub-microsecond underwater electrical explosion of conical wire arrays
Authors: Shafer D. , Gurovich V. Tz. , Gleizer S. , Gruzinsky K. , Krasik Ya. E.
Published: December 2015

The results of experiments with underwater electrical explosion of modified conical arrays of copper and aluminum wires are presented. A pulsed generator producing a 550 kA-amplitude current with a 400 ns rise time was used in the explosion of the arrays. The array explosion generates water flows converging at the axis of the cone. This flow generates a fast-moving water jet with a velocity exceeding 1.8 × 105 cm/s, which was observed being ejected from the surface of the water covering the array. The positions of the water jet were measured by multiple-exposure fast framing imaging. In experiments, the apex angle of the array, the thickness of the water layer above the arrays, or the material of the wires was altered, which changed the resulting velocities and shapes of the emitted jets. A model that considers the converging stationary flow of a slightly compressible fluid is suggested. The velocities and shapes of the jets obtained by this model agree well with the experimentally measured jet velocities.
A new model for gas–water two-immiscible-phase transport in fractal-like porous media
Authors: Li Xiao-Gang , Yi Liang-Ping , Yang Zhao-Zhong , Chen Yu-Song
Published: December 2015

A new model for gas–water two-immiscible-phase transport in a fractal-like porous medium is developed based on the assumptions that the porous medium consists of a bundle of non-interconnected tortuous capillaries and that the size distribution of the capillaries follows a power law relationship when both the capillary pressure and the compressibility of gas are considered. The model is a function of the structural parameters of the porous medium and the parameters of the fluid properties. The new model does not contain empirical constants, and every parameter has a clear physical meaning. The relative permeability predicted by the proposed model is compared with experimental data, and the comparison results are in rational agreement. Finally, the parameters influencing the relative permeability are explored.
Highly efficient conductance control in a topological insulator based magnetoelectric transistor
Authors: Duan Xiaopeng , Li Xi-Lai , Li Xiaodong , Semenov Yuriy G. , Kim Ki Wook
Published: December 2015

The spin-momentum interlocked properties of the topological insulator (TI) surface states are exploited in a transistor-like structure for efficient conductance control in the TI-magnet system. Combined with the electrically induced magnetization rotation as part of the gate function, the proposed structure takes advantage of the magnetically modulated TI electronic band dispersion in addition to the conventional electrostatic barrier. The transport analysis coupled with the magnetic simulation predicts super-steep current-voltage characteristics near the threshold along with the GHz operating frequencies. Potential implementation to a complementary logic is also examined. The predicted characteristics are most suitable for applications requiring low power or those with small signals.
Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging
Authors: DeVore M. S. , Stich D. G. , Keller A. M. , Cleyrat C. , Phipps M. E. , Hollingsworth J. A. , Lidke D. S. , Wilson B. S. , Goodwin P. M. , Werner J. H.
Published: December 2015

We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments.
Charge sensing of a few-donor double quantum dot in silicon
Authors: Watson T. F. , Weber B. , Büch H. , Fuechsle M. , Simmons M. Y.
Published: December 2015

We demonstrate the charge sensing of a few-donor double quantum dot precision placed with atomic resolution scanning tunnelling microscope lithography. We show that a tunnel-coupled single electron transistor (SET) can be used to detect electron transitions on both dots as well as inter-dot transitions. We demonstrate that we can control the tunnel times of the second dot to the SET island by ∼4 orders of magnitude by detuning its energy with respect to the first dot.
Information-theoretic model comparison unifies saliency metrics
Authors: Kümmerer Matthias , Wallis Thomas S. A. , Bethge Matthias
Published: December 2015

Significance

Where do people look in images? Predicting eye movements from images is an active field of study, with more than 50 quantitative prediction models competing to explain scene viewing behavior. Yet the rules for this competition are unclear. Using a principled metric for model comparison (information gain), we quantify progress in the field and show how formulating the models probabilistically resolves discrepancies in other metrics. We have also developed model assessment tools to reveal where models fail on the database, image, and pixel levels. These tools will facilitate future advances in saliency modeling and are made freely available in an open source software framework (www.bethgelab.org/code/pysaliency).
Bimodal rheotactic behavior reflects flagellar beat asymmetry in human sperm cells
Authors: Bukatin Anton , Kukhtevich Igor , Stoop Norbert , Dunkel Jörn , Kantsler Vasily
Published: December 2015

Significance

Successful sperm navigation is essential for sexual reproduction, yet we still understand relatively little about how sperm cells are able to adapt their swimming motion in response to chemical and physical cues. This lack of knowledge is owed to the fact that it has been difficult to observe directly the full 3D dynamics of the whip-like flagellum that propels the cell through the fluid. To overcome this deficiency, we apply a new algorithm to reconstruct the 3D beat patterns of human sperm cells in experiments under varying flow conditions. Our analysis reveals that the swimming strokes of human sperm are considerably more complex than previously thought, and that sperm may use their heads as rudders to turn right or left.
Rapid increases in immature synapses parallel estrogen-induced hippocampal learning enhancements
Authors: Phan Anna , Suschkov Sarah , Molinaro Luke , Reynolds Kathryn , Lymer Jennifer M. , Bailey Craig D. C. , Kow Lee-Ming , MacLusky Neil J. , Pfaff Donald W. , Choleris Elena
Published: December 2015

Significance

Estrogens are known to rapidly affect learning and memory, but how they do so is not well understood. Here we identify the hippocampus as a brain structure responsible for rapid estradiol-induced improvement of general discrimination learning in female mice, which coincides with a substantial increase in hippocampal dendritic spines, the postsynaptic sites of excitatory synapses. Until now, it had been assumed that estradiol-induced increases in hippocampal synapses would result in increased excitatory input into the neuron. Surprisingly, we find the opposite: increases in hippocampal spines are associated with a decrease in the excitatory glutamatergic input. This finding suggests that estradiol improves learning through inducing the formation of silent or immature synapses, which provide the substrate for storing new memories.
Cells activated for wound repair have the potential to direct collective invasion of an epithelium
Authors: Bleaken Brigid M. , Menko A. Sue , Walker Janice L.
Published: December 2015

Mechanisms regulating how groups of cells are signaled to move collectively from their original site and invade surrounding matrix are poorly understood. Here we develop a clinically relevant ex vivo injury invasion model to determine whether cells involved in directing wound healing have invasive function and whether they can act as leader cells to direct movement of a wounded epithelium through a three-dimensional (3D) extracellular matrix (ECM) environment. Similar to cancer invasion, we found that the injured cells invade into the ECM as cords, involving heterotypical cell–cell interactions. Mesenchymal cells with properties of activated repair cells that typically locate to a wound edge are present in leader positions at the front of ZO-1–rich invading cords of cells, where they extend vimentin intermediate filament–enriched protrusions into the 3D ECM. Injury-induced invasion depends on both vimentin cytoskeletal function and MMP-2/9 matrix remodeling, because inhibiting either of these suppressed invasion. Potential push and pull forces at the tips of the invading cords were revealed by time-lapse imaging, which showed cells actively extending and retracting protrusions into the ECM. This 3D injury invasion model can be used to investigate mechanisms of leader cell–directed invasion and understand how mechanisms of wound healing are hijacked to cause disease.
Optimal Mix of Vertical Integration and Contracting for Energy Crops: Effect of Risk Preferences and Land Quality
Authors: Yang Xi , Paulson Nicholas D. , Khanna Madhu
Published: December 2015

Long‐term contracts are likely to be critical to induce the production of perennial energy crops as a feedstock for the emerging cellulosic biofuel industry. This paper develops a framework to analyze the determinants of landowner choice among a land‐leasing contract, a fixed‐price contract, and a revenue‐sharing contract for energy crop production. We examine the effect of heterogeneous landowners' risk and time preferences and land quality on the optimal mix and equilibrium terms of these contracts, which jointly maximize the net benefits of the refinery and landowners in a region; this has implications for the extent to which energy crop production is likely to be vertically integrated or independently contracted by a biorefinery. We find that the refinery can potentially earn a higher profit by offering a choice of these three types of contracts rather than a single type of contract only; by allowing self‐selection of contract type based on landowner risk and time preferences, the contractual terms needed to induce production of energy crops are reduced. Although it is optimal for vertically‐integrated and contracted production to co‐exist, we find that the share of the former is predominant across a range of assumptions about the distribution of risk preferences, time preferences, and relative riskiness of conventional and energy crop production. We also find that the impact of having multiple contract types to choose from on landowners' welfare is ambiguous.
Clinical Reasoning Tasks and Resident Physicians: What Do They Reason About?
Authors: McBee Elexis , Ratcliffe Temple , Goldszmidt Mark , Schuwirth Lambert , Picho Katherine , Artino Anthony R. , Masel Jennifer , Durning Steven J.
Published: December 2015

Purpose

A framework of clinical reasoning tasks thought to occur in a clinical encounter was recently developed. It proposes that diagnostic and therapeutic reasoning comprise 24 tasks. The authors of this current study used this framework to investigate what internal medicine residents reason about when they approach straightforward clinical cases.

Method

Participants viewed three video-recorded clinical encounters portraying common diagnoses. After each video, participants completed a post encounter form and think-aloud protocol. Two authors analyzed transcripts from the think-aloud protocols using a constant comparative approach. They conducted iterative coding of the utterances, classifying each according to the framework of clinical reasoning tasks. They evaluated the type, number, and sequence of tasks the residents used.

Results

Ten residents participated in the study in 2013–2014. Across all three cases, the residents employed 14 clinical reasoning tasks. Nearly all coded tasks were associated with framing the encounter or diagnosis. The order in which residents used specific tasks varied. The average number of tasks used per case was as follows: Case 1, 4.4 (range 1–10); Case 2, 4.6 (range 1–6); and Case 3, 4.7 (range 1–7). The residents used some tasks repeatedly; the average number of task utterances was 11.6, 13.2, and 14.7 for, respectively, Case 1, 2, and 3.

Conclusions

Results suggest that the use of clinical reasoning tasks occurs in a varied, not sequential, process. The authors provide suggestions for strengthening the framework to more fully encompass the spectrum of reasoning tasks that occur in residents’ clinical encounters.
Does Fentanyl Lead to Opioid-induced Hyperalgesia in Healthy Volunteers?
Authors: Mauermann Eckhard , Filitz Joerg , Dolder Patrick , Rentsch Katharina M. , Bandschapp Oliver , Ruppen Wilhelm
Published: December 2015

AbstractAbstract

High-dose (10 μg/kg) fentanyl infusion can increase cold pressor test pain threshold and tolerance 4.5 to 6.5 h after infusion. Simultaneously, high-dose fentanyl infusion can increase the area of hyperalgesia caused by electrical burn.

Supplemental Digital Content is available in the text.

Background

Although opioids in general and remifentanil in particular have been shown to induce hyperalgesia, data regarding fentanyl are scarce. Thus, the authors investigated the effect of fentanyl dosing on pain perception and central sensitization in healthy volunteers using established pain models.

Methods

Twenty-one healthy, male volunteers were included in this randomized, double-blind, crossover study and received either intravenous low-dose (1 μg/kg) or high-dose (10 μg/kg) fentanyl. Pain intensities and hyperalgesia were assessed by intracutaneous electrical stimulation, and cold pressor pain was used as an additional measure of acute pain. The primary outcome was hyperalgesia from 4.5 to 6.5 h after fentanyl administration.

Results

A higher dose of fentanyl led to significantly decreased pain scores as measured by the numeric rating scale (0.83 units lower [95% CI, 0.63 to 1.02]; P < 0.001) but increased areas of hyperalgesia (+30.5% [95% CI, 16.6 to 44.4%]; P < 0.001) from 4.5 to 6.5 h after fentanyl administration. Allodynia did not differ between groups (+4.0% [95% CI, −15.4 to 23.5%]; P = 0.682).The high dose also led to both increased cold pressor pain threshold (+43.0% [95% CI, 29.7 to 56.3%]; P < 0.001) and tolerance (+32.5% [95% CI, 21.7 to 43.4%]; P < 0.001) at 4.5 to 6.5h. In the high-dose group, 19 volunteers (90%) required reminders to breathe, 8 (38%) required supplemental oxygen, and 12 (57%) experienced nausea.

Conclusions

A higher dose of fentanyl increased hyperalgesia from 4.5 to 6.5 h in healthy volunteers while simultaneously decreasing pain scores.
Triggered EMG Potentials in Determining Neuroanatomical Safe Zone for Transpsoas Lumbar Approach
Authors: Sarwahi Vishal , Pawar Abhijit , Sugarman Etan , Legatt Alan D. , Dworkin Aviva , Thornhill Beverly , Lo Yungtai , Wendolowski Stephen F. , Gecelter Rachel C. , Moguilevitch Marina
Published: December 2015

Study Design.

In vivo analysis in swine model.

Objective.

The purpose of this study was to determine the accuracy of triggered EMG (t-EMG) and its reliability in lateral lumbar interbody fusions surgery. We also aim to document changes in psoas muscle produced during the approach.

Summary of Background Data.

Lateral lumbar interbody fusions is preferred over direct anterior approach because of lower complications, blood loss, and shorter recovery time. Threshold-EMGs are utilized for real-time feedback about nerve location; however, neurological deficits are widely reported, and are unique to this approach. Multiple factors have been hypothesized including neuropraxia from retractors and compression from psoas hematoma/edema. The variable reports of neurological complication even with t-EMGs indicate the need to study them further.

Methods.

Eight swines underwent left-sided retroperitoneal approach. The nerve on the surface of the psoas was identified and threshold-EMGs were obtained utilizing a ball-tip, and needle probe. First EMG and threshold responses required to elicit 20-μV responses were recorded for 2 mm incremental distances up to 10 mm. In the second part, a K-wire was inserted into the mid-lumbar disc space, and a tubular retractor docked and dilated adequately. Postmortem CT scans were carried out to evaluate changes in psoas muscle.

Results.

A t-EMG stimulus threshold of <5 mA indicates a higher probability that the probe is close to or on the nerve, but this was not proportional to the distance suggesting limitations for nerve mapping. Negative predictive value of t-EMGs is 76.5% with the ball-tipped probe and 80% with the needle probe for t-EMG ≥10 mA and indicates that even with higher thresholds, the nerve may be much closer than anticipated. Postoperative hematoma was not seen on CT scans.

Conclusion.

Threshold measurements are unreliable in estimating distance from the nerve in an individual subject and higher values do not always correspond to a ‘safe zone.”

Level of Evidence: 5
SEVERE PANUVEITIS, RETINAL VASCULITIS, AND OPTIC DISK GRANULOMA SECONDARY TO SARCOIDOSIS
Authors: Patterson Michael , Bergstrom Chris S. , Clark W. Lloyd , Grossniklaus Hans E. , Payne John F.
Published: December 2015

Purpose:

To report a case of panuveitis, retinal vasculitis, and optic disk granuloma due to sarcoidosis.

Methods:

Case report and literature review.

Results:

A 26-year-old previously healthy African American male presented with four months of gradual progressive visual decline in the right eye. Clinical examination revealed severe panuveitis, retinal vasculitis, and large optic nerve mass lesion. Diffuse supraclavicular lymphadenopathy was also present. Histopathologic examination of the lymph node biopsy revealed granulomatous inflammation with some areas of caseous necrosis consistent with sarcoidosis.

Conclusion:

Sarcoidosis is a common cause of uveitis and retinal vasculitis. In rare cases, an optic disk granuloma may occur and can be treated with immunosuppressive therapy.
Methanol Kinetics in Chronic Kidney Disease After Fomepizole: A Case Report
Authors: Maskell Kevin F. , Beckett Sara , Cumpston Kirk L.
Published: December 2015

Methanol is a common toxicant in the United States, especially from automotive products. Its kinetics have been described previously and typically involve little urinary excretion. We present a case of prolonged methanol half-life in a patient with chronic kidney disease. An 80-year-old male with a baseline glomerular filtration rate of 24 mL·min−1·1.73 m−2 was transferred to our facility after unintentional methanol ingestion. The original facility had treated him with an oral ethanol load; upon arrival to our facility, he was immediately loaded with fomepizole. His initial serum methanol concentration was 66.1 mg/dL. After a risk/benefit discussion, we decided not to perform hemodialysis on the patient and he was treated with fomepizole and supportive care. After 6 days as an inpatient, the patient's methanol level had declined to 22 mg/dL, fomepizole was discontinued, and the patient was able to be discharged without apparent complications. Based on the exponential best fit line for the patient's methanol concentrations, his methanol half-life during fomepizole treatment was approximately 70 hours, significantly longer than the 30–50 hours typically reported. The reasons for this difference are unclear. This report is limited by being a single case. Further study on the kinetics of methanol in the setting of chronic kidney disease is needed.
Role of High-mobility Group Protein A Isoforms and Their Clinicopathologic Significance in Primary Retinoblastoma
Authors: Singh Mithalesh K. , Singh Lata , Sen Seema , Pushker Neelam , Sharma Anjana , Ahamad Feeroj C. , Chawla Bhavna , Kashyap Seema
Published: December 2015

Background:

High-mobility group proteins A (HMGA) are more abundant in rapidly dividing and transformed cells. These are a group of proteins regulating tumorigenesis and tumor invasion. Increased expression of HMGA1 and HMGA2 has been reported in various benign and malignant tumors. The aim of the present study was to analyze expression of HMGA1 and HMGA2 proteins in retinoblastoma.

Methods:

Protein expression of HMGA1 and HMGA2 in 80 formalin-fixed retinoblastoma tissues was performed by immunohistochemistry, and their mRNA expressions were analyzed on 40 fresh primary enucleated retinoblastoma samples by semiquantitative reverse transcription polymerase chain reaction. Results were then correlated with clinicopathologic parameters.

Results:

Immunohistochemical analysis of HMGA1 and HMGA2 was seen in 56.25% and 58.75% of retinoblastoma cases, respectively. mRNA expressions of HMGA1 and HMGA2 was found to be 57.55% and 62.5%, respectively. The mRNA results correlated well with immunostaining results. Expression of both HMGA1 and HMGA2 was significantly associated with choroidal invasion and poor tumor differentiation.

Conclusions:

HMGA1 and HMGA2 proteins may contribute to tumorigenesis of Rb. Expression of HMGA1 and HMGA2 predicts poor prognosis and could serve as a therapeutic target in the management of RB. Further experiments are needed to determine the role of these proteins as therapeutic targets in tumorigenesis.