bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement in flexibility and volumetric performance for supercapacitor application and the effect of Ni–Fe ratio on electrode behaviour
Authors: Zhang Liuyang , Gong Hao
Published: February 2015

The flexibility and volumetric performance of supercapacitors have been increased in an effective and economical way.
Efficient asymmetric transfer hydrogenation of ketones in ethanol with chiral iridium complexes of spiroPAP ligands as catalysts
Authors: Liu Wei-Peng , Yuan Ming-Lei , Yang Xiao-Hui , Li Ke , Xie Jian-Hua , Zhou Qi-Lin
Published: February 2015

Highly efficient iridium catalyzed asymmetric transfer hydrogenation of simple ketones with ethanol as a hydrogen donor has been developed, providing chiral alcohols with up to 98% ee.
Metal–semiconductor Zn/ZnO core–shell nanocables: facile and large-scale fabrication, growth mechanism, oxidation behavior, and microwave absorption performance
Authors: Zhong Bo , Tang Xiaohui , Huang Xiaoxiao , Xia Long , Zhang Xiaodong , Wen Guangwu , Chen Zi
Published: February 2015

Zn/ZnO core–shell nanocables have been fabricated on a large scale and the formation mechanism and microwave absorption properties have been investigated.
Electron density distribution studies as a tool to explore the behaviour of thiourea-based anion receptors
Authors: Kirby Isabelle L. , Pitak Mateusz B. , Wilson Claire , Gale Philip A. , Coles Simon J.
Published: February 2015

Building on previous studies of anion-receptor complexes based on a urea scaffold substituted symmetrically with electron-withdrawing nitro groups, the electron density distribution in an analogous thiourea receptor complex and the related asymmetrically substituted urea and thiourea receptors are described.
Synthesis of nano-TaOx oxygen reduction reaction catalysts on multi-walled carbon nanotubes connected via a decomposition of oxy-tantalum phthalocyanine
Authors: Ishihara A. , Chisaka M. , Ohgi Y. , Matsuzawa K. , Mitsushima S. , Ota K.
Published: February 2015

Nano-TaOx particles were supported on MWCNTs via a thermal decomposition of oxy-tantalum phthalocyanine. The ORR activity solely-originated from nano-TaOx was above 0.9 V versus RHE with larger currents than conventional micro-TaOx in acidic media.
Size and edge roughness dependence of thermal conductivity for vacancy-defective graphene ribbons
Authors: Xie Guofeng , Shen Yulu
Published: February 2015

By incorporating the phonon–phonon scattering, phonon-boundary scattering and phonon-vacancy scattering into the linearized Boltzmann transport equation, we theoretically investigate the effects of size and edge roughness on thermal conductivity of single vacancy-defective graphene ribbons.
Simultaneous detection of electronic structure changes from two elements of a bifunctional catalyst using wavelength-dispersive X-ray emission spectroscopy and in situ electrochemistry
Authors: Gul Sheraz , Ng Jia Wei Desmond , Alonso-Mori Roberto , Kern Jan , Sokaras Dimosthenis , Anzenberg Eitan , Lassalle-Kaiser Benedikt , Gorlin Yelena , Weng Tsu-Chien , Zwart Petrus H. , Zhang Jin Z. , Bergmann Uwe , Yachandra Vittal K. , Jaramillo Thomas F. , Yano Junko
Published: February 2015

A method of simultaneously probing the electronic structure of multiple metal centers using wavelength-dispersive X-ray emission spectroscopy was developed.
Radical-cation salts of BEDT-TTF with lithium tris(oxalato)metallate(iii)
Authors: Martin Lee , Engelkamp Hendrik , Akutsu Hiroki , Nakatsuji Shin'ichi , Yamada Jun'ichi , Horton Peter , Hursthouse Michael B.
Published: February 2015

The first radical-cation salts in the extensive family (BEDT-TTF)x[(A)M(C2O4)3]·Guest containing lithium as the counter cation have been synthesized and characterised.
Synthesis, characterization and structure of nickel and copper compounds containing ligands derived from keto-enehydrazines and their catalytic application for aerobic oxidation of alcohols
Authors: Gaona Miguel Ángel , Montilla Francisco , Álvarez Eleuterio , Galindo Agustín
Published: February 2015

Compounds [M(LR,Ph)2] (M = Cu, Ni; R = Me, Ph) containing ligands derived from keto-enehydrazines were synthesised and characterised. Cu-derivatives, with TEMPO, were good catalysts for the aerobic oxidation of alcohols.
Oxidative cleavage of allyl ethers by an oxoammonium salt
Authors: Kelly Christopher B. , Ovian John M. , Cywar Robin M. , Gosselin Taylor R. , Wiles Rebecca J. , Leadbeater Nicholas E.
Published: February 2015

A method to oxidatively cleave allyl ethers to their corresponding aldehydes mediated by an oxoammonium salt is described. Using a biphasic solvent system and mild heating, cleavage proceeds readily, furnishing a variety of α,β-unsaturated aldehydes and ketones.
A dual stimuli responsive fluorescent probe carrier from a double hydrophilic block copolymer capped with β-cyclodextrin
Authors: Yang Guang , Yang Zhen , Mu Chengguang , Fan Xiaodong , Tian Wei , Wang Qing
Published: February 2015

A β-cyclodextrin terminated triblock copolymer with both hydrophilic temperature and pH sensitive segments was prepared and characterized in terms of self-assembling and encapsulation behaviors.
Electron induced chemistry of thiophene
Authors: Vinodkumar Minaxi , Desai Hardik , Vinodkumar P. C.
Published: February 2015

A comprehensive theoretical study of electron scattering with thiophene over a wide impact energy range is reported in this article.
Magnetic molecularly imprinted microsensor for selective recognition and transport of fluorescent phycocyanin in seawater
Authors: Zhang Zhong , Li Jinhua , Fu Longwen , Liu Dongyan , Chen Lingxin
Published: February 2015

Magnetically imprinted microsensors for selective recognition/transport of phycocyanin, presenting real-time visualization monitoring of phycocyanin and direct observation of motion trajectories.
Nanoflower-like weak crystallization manganese oxide for efficient removal of low-concentration NO at room temperature
Authors: Wang Jin , Zhu Jinzhen , Zhou Xiaoxia , Du Yanyan , Huang Weimin , Liu Jianjun , Zhang Wenqing , Shi Jianlin , Chen Hangrong
Published: February 2015

The efficient removal of low-concentration nitric oxide at room temperature from a semi-closed space is becoming a crucial but challenging issue in the context of increasingly serious air pollution.
Synthesis of hexagonal MoO3 nanorods and a study of their electrochemical performance as anode materials for lithium-ion batteries
Authors: Zhou Jianbin , Lin Ning , Wang Liangbiao , Zhang Kailong , Zhu Yongchun , Qian Yitai
Published: February 2015

h-MoO3 nanorods with a diameter of 40 nm are synthesized in an immiscible mixture of solutions and exhibit high electrochemical performance.
H2 purification by functionalized graphdiyne – role of nitrogen doping
Authors: Jiao Yan , Du Aijun , Smith Sean C. , Zhu Zhonghua , Qiao Shi Zhang
Published: February 2015

Nitrogen doping into graphdiyne leads to a reduced H2 diffusion barrier and hence an enhanced hydrogen purification capability.
Highly transparent and flexible polyimide–AgNW hybrid electrodes with excellent thermal stability for electrochromic applications and defogging devices
Authors: Lu Heng-Yi , Chou Chin-Yen , Wu Jia-Hao , Lin Jiang-Jen , Liou Guey-Sheng
Published: February 2015

By introducing colorless polyimide as a binder, an AgNW transparent electrode exhibited excellent thermal stability, bendability, and adhesion properties.
Revamped fly‐over for accurate colon visualisation in virtual colonoscopy
Authors: Ismail Marwa , Elshzaly Salwa , Farag Aly , Sites Chuck , Curtin Robert , Falk Robert , Seow Albert , Dryden Gerald
Published: February 2015

This study revisits a visualisation technique for virtual colonoscopy, known as virtual fly‐over (FO). The method views the entire colon anatomy from above the centreline. It assigns two cameras located on opposite sides of the centreline, each of which is responsible for viewing one half of the colon. This approach has several advantages over related colon visualisation methods with regards to visibility coverage and polyp detection rate. However, the traditional FO implementation created a few drawbacks that hinder complete visualisation. For example, it could overlook polyps located on the line between the two halves, and it has no data‐specific initialisation for cutting planes. The authors enhance the FO method in a number of respects in this study: resolve the cutting issue and improve the virtual camera setup in order to better visualise both the colon surface's hidden structures and polyps that are difficult to locate. Quantitative validation of the revamped FO on 30 actual clinical datasets with complicated shapes and large volumes demonstrated that the average surface visualisation rate is equal to 99.5 ± 0.2%. Also, true and synthetic polyps with various shapes and sizes were used to clinically validate the proposed method. Detection rate is up to 100% on the tested sets.
Optimisation of the dislocation filter layers in 1.3‐μm InAs/GaAs quantum‐dot lasers monolithically grown on Si substrates
Authors: Tang Mingchu , Wu Jiang , Chen Siming , Jiang Qi , Seeds Alwyn J. , Liu Huiyun , Dorogan Vitaliy G. , Benamara Mourad , Mazur Yuriy , Salamo Gregory
Published: February 2015

The authors report 1.3‐μm InAs/GaAs quantum‐dot (QD) lasers monolithically grown on a Si substrate by optimising the dislocation filter layers (DFLs). InAlAs/GaAs strained layer superlattices (SLSs) have been presented as DFLs in this study. A distinct improvement in the InAs/GaAs QDs was observed when using InAlAs/GaAs SLSs because of the effective filtering of threading dislocations. Consequently, a laser with a threshold current density of 194 A/cm2 at room temperature and an operating temperature as high as 85°C is successfully demonstrated. These results show the potential for integrating III–V QD materials on a Si platform via InAlAs/GaAs SLSs as DFL.
Spin echo small angle neutron scattering using a continuously pumped 3He neutron polarisation analyser
Authors: Parnell S. R. , Washington A. L. , Li K. , Yan H. , Stonaha P. , Li F. , Wang T. , Walsh A. , Chen W. C. , Parnell A. J. , Fairclough J. P. A. , Baxter D. V. , Snow W. M. , Pynn R.
Published: February 2015

We present a new instrument for spin echo small angle neutron scattering (SESANS) developed at the Low Energy Neutron Source at Indiana University. A description of the various instrument components is given along with the performance of these components. At the heart of the instrument are a series of resistive coils to encode the neutron trajectory into the neutron polarisation. These are shown to work well over a broad range of neutron wavelengths. Neutron polarisation analysis is accomplished using a continuously operating neutron spin filter polarised by Rb spin-exchange optical pumping of 3He. We describe the performance of the analyser along with a study of the 3He polarisation stability and its implications for SESANS measurements. Scattering from silica Stöber particles is investigated and agrees with samples run on similar instruments.
Mössbauer cell for low-temperature studies of catalysts under reaction conditions
Authors: Pérez De Berti I. , Bengoa J. , Fellenz N. , Mercader R. , Marchetti S.
Published: February 2015

Mössbauer spectroscopy is an essential tool to investigate the structure of Fe supported catalysts and their changes, when they are used in the Fischer-Tropsch synthesis. A cell, that allows keeping the samples in the same atmosphere of the reduction treatment, was designed in order to characterize the Fe species without changing the working atmosphere avoiding the oxidation. It allows to measure at low temperatures in a helium closed-cycle refrigerator. Besides, this cell is useful to perform Mössbauer measurements on the used catalysts, preserving the oxidation of its species, using an inert atmosphere. In this work, we describe the details of this new cell and, as an example of its utility, we present the results obtained with a system of 12 nm iron oxide nanoparticles supported on a mesoporous silica matrix.
Quartz-enhanced photoacoustic spectroscopy sensor for ethylene detection with a 3.32 μm distributed feedback laser diode
Authors: Nguyen Ba T. , Triki M. , Desbrosses G. , Vicet A.
Published: February 2015

An antimonide distributed feedback quantum wells diode laser operating at 3.32 μm at near room temperature in the continuous wave regime has been used to perform ethylene detection based on quartz enhanced photoacoustic spectroscopy. An absorption line centered at 3007.52 cm−1 was investigated and a normalized noise equivalent absorption coefficient (1σ) of 3.09 10−7 cm−1 W Hz−1/2 was obtained. The linearity and the stability of the detection have been evaluated. Biological samples’ respiration has been measured to validate the feasibility of the detection setup in an agronomic environment, especially on ripening apples.
Modeling of the dynamic characteristic of viscoelastic dielectric elastomer actuators subject to different conditions of mechanical load
Authors: Zhang Junshi , Tang Liling , Li Bo , Wang Yanjie , Chen Hualing
Published: February 2015

Subject to a mechanical load or a voltage, a membrane of a dielectric elastomer deforms. As for the deformation mode, the dynamic performance and stability are strongly affected by how mechanical forces are applied. In the current study, by using the Euler-Lagrange equation, an analytical model is developed to characterize the dynamic performance of a homogeneously deformed viscoelastic dielectric elastomer under the conditions of equal-biaxial force, uniaxial force, and pure shear state, respectively. Numerical results are shown to describe the electromechanical deformation and stability. It is observed that the resonant frequency (where the amplitude-frequency curve peaks) has dependencies on the deformation mode, the level of mechanical load, and the applied electric field. When a dielectric elastomer membrane is subject to equal-biaxial force or pure shear state, it undergoes a nonlinear quasi-periodic vibration. An aperiodic motion of the dielectric elastomer system is induced by the boundary condition of a uniaxial force.
Sintered tantalum carbide coatings on graphite substrates: Highly reliable protective coatings for bulk and epitaxial growth
Authors: Nakamura Daisuke , Suzumura Akitoshi , Shigetoh Keisuke
Published: February 2015

Highly reliable low-cost protective coatings have been sought after for use in crucibles and susceptors for bulk and epitaxial film growth processes involving wide bandgap materials. Here, we propose a production technique for ultra-thick (50–200 μmt) tantalum carbide (TaC) protective coatings on graphite substrates, which consists of TaC slurry application and subsequent sintering processes, i.e., a wet ceramic process. Structural analysis of the sintered TaC layers indicated that they have a dense granular structure containing coarse grain with sizes of 10–50 μm. Furthermore, no cracks or pinholes penetrated through the layers, i.e., the TaC layers are highly reliable protective coatings. The analysis also indicated that no plastic deformation occurred during the production process, and the non-textured crystalline orientation of the TaC layers is the origin of their high reliability and durability. The TaC-coated graphite crucibles were tested in an aluminum nitride (AlN) sublimation growth process, which involves extremely corrosive conditions, and demonstrated their practical reliability and durability in the AlN growth process as a TaC-coated graphite. The application of the TaC-coated graphite materials to crucibles and susceptors for use in bulk AlN single crystal growth, bulk silicon carbide (SiC) single crystal growth, chemical vapor deposition of epitaxial SiC films, and metal-organic vapor phase epitaxy of group-III nitrides will lead to further improvements in crystal quality and reduced processing costs.
Phase diagram of water confined in MCM-41 up to 700 MPa
Authors: Pajzderska A. , Bilski P. , Wąsicki J.
Published: February 2015

On the basis of measurements of NMR signal intensity and T1 and T2* relaxation times as a function of temperature (290 K–170 K) and pressure (0.1 MPa–700 MPa), the p-T phase diagram was made for the sample containing water inside and outside MCM-41 pores of 1.81 nm in radius. The temperature of nucleation of water confined in nanopores under normal pressure was 230 K. With increasing pressure this temperature decreased to 200 K under 300 MPa, but with further increase in pressure it did not change.
Enhanced damage buildup in C+-implanted GaN film studied by a monoenergetic positron beam
Authors: Li X. F. , Chen Z. Q. , Liu C. , Zhang H. J. , Kawasuso A.
Published: February 2015

Wurtzite GaN films grown by hydride vapor phase epitaxy were implanted with 280 keV C+ ions to a dose of 6 × 1016 cm−2. Vacancy-type defects in C+-implanted GaN were probed using a slow positron beam. The increase of Doppler broadening S parameter to a high value of 1.08–1.09 after implantation indicates introduction of very large vacancy clusters. Post-implantation annealing at temperatures up to 800 °C makes these vacancy clusters to agglomerate into microvoids. The vacancy clusters or microvoids show high thermal stability, and they are only partially removed after annealing up to 1000 °C. The other measurements such as X-ray diffraction, Raman scattering and Photoluminescence all indicate severe damage and even disordered structure induced by C+-implantation. The disordered lattice shows a partial recovery after annealing above 800 °C. Amorphous regions are observed by high resolution transmission electron microscopy measurement, which directly confirms that amorphization is induced by C+-implantation. The disordered GaN lattice is possibly due to special feature of carbon impurities, which enhance the damage buildup during implantation.
Metal-enhanced fluorescence from zinc substrates can lead to spectral distortion and a wavelength dependence
Authors: Hamo Hilla Ben , Karolin Jan , Mali Buddha , Kushmaro Ariel , Marks Robert , Geddes Chris D.
Published: February 2015

Metal-enhanced fluorescence enhancement factors up to 7-fold have been observed for Basic Fuchsin (BF) in close proximity to Zinc nano particulate substrates. In addition, the emission spectra of BF close-to Zinc as compared to a control sample are heavily distorted, particularly on the red-edge, giving systematic trends in enhancement, anywhere from 3- to 7-fold. We discuss these remarkable wavelength dependent effects with regard to the mechanism of metal-enhanced fluorescence.
Alkali-metal/alkaline-earth-metal fluorine beryllium borate NaSr3Be3B3O9F4 with large nonlinear optical properties in the deep-ultraviolet region
Authors: Reshak A. H. , Huang Hongwei , Kamarudin H. , Auluck S.
Published: February 2015

The linear optical response and second harmonic generation (SHG) in alkali-metal/alkaline-earth-metal fluorine beryllium borate NaSr3Be3B3O9F4 are investigated by means of density functional theory. Calculations are performed using four types of exchange correlations: Ceperley-Alder local density approximation, Perdew Burke and Ernzerhof general gradient approximation, Engel-Vosko generalized gradient approximation, and the recently modified Becke-Johnson potential (mBJ). The mBJ approach brings the calculated band gap (7.20 eV) in excellent agreement with the experimental one (7.28 eV). The calculated values of the uniaxial anisotropy δε=−0.076 and the birefringence Δn(0)=0.052 indicate considerable anisotropy in the linear optical properties, which makes it favorable for the second harmonic generation. The dominant component of the second harmonic generation is χ111(2)(ω). The value of |χ111(2)(ω)| is about 1.2 pm/V at λ = 1064 nm in agreement with previous calculations. To analyze the origin of the high SHG of NaSr3Be3B3O9F4 single crystals, we have correlated the features of |χ111(2)(ω)| spectra with the features of ε2(ω) spectra as a function of ω/2 and ω. From the calculated dominant component |χ111(2)(ω)|, we find that the microscopic first hyperpolarizability, β111, the vector components along the dipole moment direction is 0.5 × 10−30 esu at static limit and 0.6 × 10−30 esu at λ = 1064 nm.
Influence of molecular orientation on the coupling of surface plasmons to excitons in semitransparent inverted organic solar cells
Authors: Gruber Mark , Mayr Michael , Lampe Thomas , Gallheber Björn-Christoph , Scholz Bert J. , Brütting Wolfgang
Published: February 2015

We investigate the coupling between surface plasmons and excitons for different donor materials in semitransparent organic solar cells. Surface plasmons can be excited at the interface between the semitransparent anode and the surrounding dielectric medium in Kretschmann configuration, if the resonance condition for wavelength and angle is fulfilled. In solar cells with nearly upright standing diindenoperylene donor molecules in close proximity to the metal, this can lead to an enhancement in photo-current. By contrast, for cells with dibenzo-tetraphenyl-periflanthen as donor, the lying orientation of molecules is unfavorable for coupling to surface plasmons. In this case, the excitation of surface plasmons acts like a parasitic absorption and reduces the photo-current.
Estimation of genetic parameters for lambing ease, birthweight and gestation length in Australian sheep
Authors: Li L. , Brown D. J.
Published: February 2015

This study presents estimates of genetic parameters for lambing ease (LE), birthweight (BW) and gestation length (GL) in Australian terminal sire sheep breeds using data from the Sheep Genetics LAMBPLAN database. LE was scored on lambs on a 1–5 scale, with 1 being no assistance and 5 being other such as special veterinary assistance. The full dataset consisted of 43 448 records on LE and its two subsets (the single and twin subsets) based on the birth type of the litter were analysed. Four models with different combinations of random effects consisting of direct genetic, maternal genetic and maternal permanent environmental effects were compared. All traits were analysed using linear animal models and linear sire models with LE further analysed by threshold sire models for all datasets to evaluate the influence of datasets and models on the estimation of genetic parameters. The results showed that multiple-born lambs had shorter GL, less BW and less lambing difficulty than single-born lambs. Lambing difficulty decreased with the increase of dam age from 1.5 to 4.5 years, and then increased afterwards. Genetic parameters using linear animal models were similar to those using linear sire models for all traits. Phenotypic variance and direct heritability were higher for single-born lambs compared with twin-born lambs. No significant maternal permanent environmental effect was detected for LE. Based on results using linear animal models with the full dataset, the direct heritabilities were 0.06 ± 0.01, 0.15 ± 0.01 and 0.52 ± 0.02, the maternal heritabilities were 0.03 ± 0.01, 0.15 ± 0.01 and 0.13 ± 0.02 for LE, BW and GL, respectively. The proportions of maternal permanent environmental effects to the total variances were 0.13 ± 0.01 for BW. Low to moderate direct genetic correlations of 0.31 ± 0.09 (LE and BW), 0.24 ± 0.11 (LE and GL) and 0.08 ± 0.08 (BW and GL) were estimated using tri-variate analysis from the full dataset, indicating the trend that lambs with greater BW and longer GL would result in more lambing difficulty.
Food preferences of the estuarine crab Sesarma catenata estimated through laboratory experiments
Authors: Bergamino Leandro , Richoux Nicole B.
Published: February 2015

Feeding by sesarmid crabs on plants represents an important energy pathway within some estuarine ecosystems. We examined the trophic ecology of estuarine sesarmid crabs Sesarma catenata through a series of laboratory feeding-preference experiments. Our experiments considered decomposed and mature leaves of terrestrial riparian trees, marsh plants Chenolea diffusa and Sarcocornia perennis and the marshgrass Spartina maritima as potential food items. S. catenata preferred decomposed leaves of terrestrial riparian trees, followed by decomposed and mature leaves of S. maritima. We suggest that the low carbon:nitrogen (C:N) ratios of S. maritima and high bacterial production associated with decomposed terrestrial leaves may explain the trophic behaviour of S. catenata. The faecal production by S. catenata during these experiments confirmed the preferential assimilation of decomposed material by the crabs. By combining the consumption rates with an estimated density of S. catenata within the local estuary that it inhabits, we suggest that moderate proportions of the leaf material can potentially be consumed by this species (34% of total leaf litter), leaving substantial amounts of unconsumed leaf litter that may represent an important subsidy for adjacent environments. Our results validate previously published trophic data, showing the value of linking feeding experiments with biological tracers to improve food-web models.
Pharmacological recruitment of aldehyde dehydrogenase 3A1 (ALDH3A1) to assist ALDH2 in acetaldehyde and ethanol metabolism in vivo
Authors: Chen Che-Hong , Cruz Leslie A. , Mochly-Rosen Daria
Published: February 2015

Significance

About 560 million East Asians have an impaired ability to eliminate acetaldehyde because of a point mutation in an enzyme called aldehyde dehydrogenase 2 (ALDH2). Humans with this mutation have ∼20-fold higher blood acetaldehyde levels than those with normal enzyme activity after consuming one to two units of alcoholic beverages. Because acetaldehyde is a potent carcinogen and causes behavioral impairment, its accumulation is a health risk. We identified a pharmacologic agent that recruits ALDH3A1, a closely related enzyme, to compensate for a loss of ability of ALDH2 to metabolize acetaldehyde. Pharmacologic agents that alter substrate specificity of an enzyme have not yet been described and may have wide clinical application in treating patients with impaired ability to detoxify toxic substances.
Large number of rebounding/founder HIV variants emerge from multifocal infection in lymphatic tissues after treatment interruption
Authors: Rothenberger Meghan K. , Keele Brandon F. , Wietgrefe Stephen W. , Fletcher Courtney V. , Beilman Gregory J. , Chipman Jeffrey G. , Khoruts Alexander , Estes Jacob D. , Anderson Jodi , Callisto Samuel P. , Schmidt Thomas E. , Thorkelson Ann , Reilly Cavan , Perkey Katherine , Reimann Thomas G. , Utay Netanya S. , Nganou Makamdop Krystelle , Stevenson Mario , Douek Daniel C. , Haase Ashley T. , Schacker Timothy W.
Published: February 2015

Significance

Antiretroviral therapy (ART) effectively suppresses HIV replication; however, treatment cannot be stopped, because latently infected CD4+ T cells will rekindle infection. As one estimate of the size of the pool of latently infected cells that must be purged for cure, we asked whether recrudescent infection is the result of reactivation from one or a larger number latently infected cells. We briefly stopped ART in fully suppressed patients to see how widespread new infections were in the lymphoid tissues (LTs) and how diverse rebounding/founder viruses were in peripheral blood. Recrudescent infection was detectable in multiple different LTs, and the population was genetically diverse, consistent with reactivation from a larger number of cells. These findings underscore the challenges facing strategies to eradicate HIV infection.
Cross-language differences in the brain network subserving intelligible speech
Authors: Ge Jianqiao , Peng Gang , Lyu Bingjiang , Wang Yi , Zhuo Yan , Niu Zhendong , Tan Li Hai , Leff Alexander P. , Gao Jia-Hong
Published: February 2015

Significance

Language processing is generally left hemisphere dominant. However, whether the interactions among the typical left hemispheric language regions differ across different languages is largely unknown. An ideal method to address this question is modeling cortical interactions across language groups, but this is usually constrained by the model space with the prior hypothesis due to massive computation demands. With cloud-computing, we used functional MRI dynamic causal modeling analysis to compare more than 4,000 models of cortical dynamics among critical language regions in the temporal and frontal cortex, established the bias-free information flow maps that were shared or specific for processing intelligible speech in Chinese and English, and revealed the neural dynamics between the left and right hemispheres in Chinese speech comprehension.
Network compensation of cyclic GMP-dependent protein kinase II knockout in the hippocampus by Ca
2+
-permeable AMPA receptors
Authors: Kim Seonil , Titcombe Roseann F. , Zhang Hong , Khatri Latika , Girma Hiwot K. , Hofmann Franz , Arancio Ottavio , Ziff Edward B.
Published: February 2015

Significance

Deletion of genes in organisms does not always give rise to phenotypes because of the existence of compensation, even though phenotypes may be found when gene activity is blocked acutely. The cGMP-dependent kinase II knockout is a typical example of this apparent paradox. The knockout shows no evident impairment of LTP, whereas acute inhibition of kinase activity significantly decreases it. This paper describes a previously unidentified form of network-based compensation for cGMP-dependent kinase II gene knockout that is not dependent on expression of duplicate or paralogous genes. Furthermore, the compensation described here is mediated by a mechanism similar to that used by activity-dependent homeostatic synaptic plasticity, suggesting that neurons in complex brains may overcome an unexpected genetic lesion by using existing homeostatic mechanisms.
Differential fates of biomolecules delivered to target cells via extracellular vesicles
Authors: Kanada Masamitsu , Bachmann Michael H. , Hardy Jonathan W. , Frimannson Daniel Omar , Bronsart Laura , Wang Andrew , Sylvester Matthew D. , Schmidt Tobi L. , Kaspar Roger L. , Butte Manish J. , Matin A. C. , Contag Christopher H.
Published: February 2015

Significance

Extracellular vesicle (EV)-mediated transfer of macromolecules may play a key role in cellular communication and may have utility in directed molecular therapies. In addition, the EV packaged biomolecules in serum may have potential for diagnosing cancer and determining its likelihood of metastasis. EVs are heterogeneous and there are many outstanding questions associated with biogenesis, uptake, and the fate of transferred molecules in recipient cells. In fact, the function, characterization, and even the nomenclature of EVs are being refined. Here we aimed to improve the functional characterization of EVs, and observed that only microvesicles (MVs), but not exosomes, can functionally transfer loaded reporter molecules to recipient cells, largely by delivering plasmid DNA. Our data show that exosomes and MVs are structurally and functionally distinct.
Understanding Maximum Size in the Catch: Atlantic Blue Marlin as an Example
Authors: Goodyear C. Phillip
Published: February 2015

Mean and maximum sizes in the catch are readily understood by both fishermen and scientists as important indicators of population health, but the maximum is more complicated to interpret because it increases with the number of observations. Size distributions of catches were computed for stable age distributions of hypothetical Atlantic populations of Blue Marlin Makaira nigricans. Fishing mortality rates were selected that reduced the population per age‐1 recruit by 25, 50, 67, 75, and 90% by number from the unfished state. A new metric, NZ50, was applied to evaluate the performance of maximum size as an indicator of population status. Sample sizes required to include large marlin in a set of observations increased to disproportionately large numbers with increased fishing. With the best estimates of growth and a natural mortality of 0.1, the number of random observations required for a 50% probability of including a 350‐cm individual increased by about 43% when the population was depressed by 25%. This value rose to more than 50‐fold when the population was reduced below 10%. In contrast, mean lengths were reduced by only 1.6% to 14% and mean weights by 5% to 45% for the same range of fishing. These results provide quantitative evidence confirming the view that a diminished number of large fish is a sensitive indicator of excessive fishing, even when mean size of the catch shows only a small change. Increased catches above large size thresholds or nearing historical maxima could be sensitive indicators of stock recovery. Measures of the frequency of occurrence of individuals above some threshold defined for large fish will generally be superior to the maximuma observed in a sample (or set of samples) as a biological reference criterion because of the stochastic nature of individual observations.

Received July 31, 2014; accepted October 31, 2014
Spawning Distribution of Bering Ciscoes in the Yukon River
Authors: Brown Randy J. , Daum David W.
Published: February 2015

Bering CiscoesCoregonus laurettaeare anadromous salmonids with known spawning populations only in the Yukon, Kuskokwim, and Susitna rivers in Alaska. A commercial fishery for the species was recently initiated at the mouth of the Yukon River, inspiring a series of research projects to enhance our understanding of the exploited population. This study was designed to delineate the geographic spawning distribution of Bering Ciscoes in the Yukon River. One hundred radio transmitters per year in 2012 and 2013 were deployed in prespawning Bering Ciscoes at a site located 1,176 km upstream from the sea. A total of 160 fish survived fish wheel capture and tagging, avoided harvest and predation after tagging, and continued migrating upstream to their spawning destinations. Approximately 79% migrated to spawn in the upper Yukon Flats, upstream from the mouth of the Porcupine River, and 21% migrated to spawn in the lower Yukon Flats. Locating the Bering Cisco spawning area, which is almost entirely encompassed by the Yukon Flats National Wildlife Refuge, enhances our ability to protect it from anthropogenic disturbance and enables future biological research on the spawning population.

Received July 25, 2014; accepted November 13, 2014
Bradykinin-mediated angioedema: factors associated with admission to an intensive care unit, a multicenter study
Authors: Javaud Nicolas , Floccard Bernard , Gontier Florian , Lapostolle Frédéric , Boccon-Gibod Isabelle , Martin Ludovic , Amarger Stéphanie , Boumedienne Abdalia , Boubaya Marouane , Asfar Pierre , Coppere Brigitte , Ollivier Yann , Bouillet Laurence , Adnet Frédéric , Fain Olivier
Published: February 2015

Objective

Bradykinin-mediated angioedema is characterized by transient attacks of localized edema of subcutaneous or submucosal tissues and can be life-threatening when involving the upper airways. The aim of this study was to determine the features of acute attacks that might be associated with admission to an ICU.

Patients and methods

We carried out a retrospective, multicenter, observational study in consecutive patients attending one of six reference centers in France for acute bradykinin-mediated angioedema attacks. Patients had been hospitalized for an acute episode at least once previously. Acute attacks requiring ICU admission were compared with acute attacks that had not required ICU admission.

Results

Overall, 118 acute attacks in 31 patients were analyzed (10 patients with hereditary angioedema, 19 patients with angiotensin-converting enzyme inhibitor-induced angioedema, and two patients with acquired C1-inhibitor deficiency angioedema). In multivariate analysis, upper airway involvement, corticosteroid, and C1-inhibitor concentrate administration were associated with ICU admission. Seven episodes (18%) needed airway protection. The evolution was favorable in 38 of 39 attacks warranting ICU admission: patients were able to get out of the service (mean ICU stay 4±5 days). One death was observed by asphyxiation because of laryngeal swelling.

Conclusion

Upper airway involvement is an independent risk factor for ICU admission. Corticosteroid use, which is an ineffective treatment, and C1-inhibitor concentrate use are factors for ICU admission. The presence of upper airway involvement should be a warning signal that the attack may be severe.
Education, exposure and experience of prehospital teams as quality indicators in regional trauma systems
Authors: Van Der Eng Dorien M. , van Beeck Eduard F. , Hoogervorst Elizabeth M. , Bierens Joost J.L.M.
Published: February 2015

Objective

Indicators to measure the quality of trauma care may be instrumental in benchmarking and improving trauma systems. This retrospective, observational study investigated whether data on three indicators for competencies of Dutch trauma teams (i.e. education, exposure, experience; agreed upon during a prior Delphi procedure) can be retrieved from existing registrations. The validity and distinctive power of these indicators were explored by analysing available data in four regions.

Methods

Data of all polytrauma patients treated by the Helicopter Emergency Medical Services were collected retrospectively over a 1-year period. During the Delphi procedure, a polytrauma patient was defined as one with a Glasgow Coma Scale of 9 or less or a Paediatric Coma Scale of 9 or less, together with a Revised Trauma Score of 10 or less. Information on education, exposure and experience of the Helicopter Emergency Medical Services physician and nurse were registered for each patient contact.

Results

Data on 442 polytrauma patients could be retrieved. Of these, according to the Delphi consensus, 220 were treated by a fully competent team (i.e. both the physician and the nurse fulfilled the three indicators for competency) and 22 patients were treated by a team not fulfilling all three indicators for competency. Across the four regions, patients were treated by teams with significant differences in competencies (P=0.002).

Conclusion

The quality indicators of education, exposure and experience of prehospital physicians and nurses can be measured reliably, have a high level of usability and have distinctive power.
Eyelashes divert airflow to protect the eye
Authors: Amador Guillermo J. , Mao Wenbin , DeMercurio Peter , Montero Carmen , Clewis Joel , Alexeev Alexander , Hu David L.
Published: February 2015

Eyelashes are ubiquitous, although their function has long remained a mystery. In this study, we elucidate the aerodynamic benefits of eyelashes. Through anatomical measurements, we find that 22 species of mammals possess eyelashes of a length one-third the eye width. Wind tunnel experiments confirm that this optimal eyelash length reduces both deposition of airborne particles and evaporation of the tear film by a factor of two. Using scaling theory, we find this optimum arises because of the incoming flow's interactions with both the eye and eyelashes. Short eyelashes create a stagnation zone above the ocular surface that thickens the boundary layer, causing shear stress to decrease with increasing eyelash length. Long eyelashes channel flow towards the ocular surface, causing shear stress to increase with increasing eyelash length. These competing effects result in a minimum shear stress for intermediate eyelash lengths. This design may be employed in creating eyelash-inspired protection for optical sensors.
Quality assessment for different haplotyping methods and GWAS sensitivity to phasing errors
Authors: Busonera Giovanni , Cogoni Marco , Zanetti Gianluigi
Published: February 2015

In this report we present a multimarker association tool (Flash) based on a novel algorithm to generate haplotypes from raw genotype data. It belongs to the entropy minimization class of methods [4, 7] and is composed of a two stage deterministic - heuristic part and of a optional stochastic optimization. This algorithm is able to scale up well to handle huge datasets with faster performance than the competing technologies such as BEAGLE[5] and MACH[10] while maintaining a comparable accuracy. A quality assessment of the results is carried out by comparing the switch error. Finally, the haplotypes are used to perform a haplotype-based Genome-wide Association Study (GWAS). The association results are compared with a multimarker and a single SNP association test performed with Plink [12]. Our experiments confirm that the multimarker association test can be more powerful than the single SNP one as stated in the literature. Moreover, Flash and Plink show similar results for the multimarker association test but Flash speeds up the computation time of about an order of magnitude using 5 SNP size haplotypes.
Advanced ensemble modelling of flexible macromolecules using X-ray solution scattering
Authors: Tria Giancarlo , Mertens Haydyn D. T. , Kachala Michael , Svergun Dmitri I.
Published: February 2015

Dynamic ensembles of macromolecules mediate essential processes in biology. Understanding the mechanisms driving the function and molecular interactions of `unstructured' and flexible molecules requires alternative approaches to those traditionally employed in structural biology. Small-angle X-ray scattering (SAXS) is an established method for structural characterization of biological macromolecules in solution, and is directly applicable to the study of flexible systems such as intrinsically disordered proteins and multi-domain proteins with unstructured regions. TheEnsemble Optimization Method(EOM) [Bernadóet al.(2007).J. Am. Chem. Soc.129, 5656–5664] was the first approach introducing the concept of ensemble fitting of the SAXS data from flexible systems. In this approach, a large pool of macromolecules covering the available conformational space is generated and a sub-ensemble of conformers coexisting in solution is selected guided by the fit to the experimental SAXS data. This paper presents a series of new developments and advancements to the method, including significantly enhanced functionality and also quantitative metrics for the characterization of the results. Building on the original concept of ensemble optimization, the algorithms for pool generation have been redesigned to allow for the construction of partially or completely symmetric oligomeric models, and the selection procedure was improved to refine the size of the ensemble. Quantitative measures of the flexibility of the system studied, based on the characteristic integral parameters of the selected ensemble, are introduced. These improvements are implemented in the newEOMversion 2.0, and the capabilities as well as inherent limitations of the ensemble approach in SAXS, and ofEOM2.0 in particular, are discussed.
The influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution
Authors: Zhang Jie , Liu Jing , Hu Qian , Huang Feng , Cheng ZhaoYang , Guo JunTao
Published: February 2015

Purpose

– The aim of this paper was to clarify the influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution and attempt to understand mechanistic aspects of the corrosion behaviors of X80 under these conditions.

Design/methodology/approach

– The electrochemical behavior of X80 steel at various tensile stresses was investigated in a simulated acid soil solution using electrochemical impedance spectroscopy, potentiodynamic scan measurements and surface analysis techniques.

Findings

– The results show that as tensile stress was increased, the open-circuit potential decreased, the reaction activity increase, the reaction resistance (Rct)value became smaller by degrees, the corrosion product film resistance (Rf) first decreased and then increased and polarization current densities changed conversely. The corrosion product film was compact and continuous under the low stress, whereas it was relatively loose under high-stress conditions. Tensile stress promotes the movement of dislocations, which become active points when they move to the steel surface. The increase in the number of active points enhances the anodic dissolution rate and promotes the formation of corrosion product film whose blocking effect can decrease the dissolution rate. The corrosion rate of the specimen is determined by these two effects.

Originality/value

– This research provides an essential insight into the mechanism of the electrochemical behavior of X80 steel in acid soil environments.
Surface active hyperbranched polyamide-ester as a corrosion inhibitor for carbon steel in both neutral and acidic media
Authors: Mohamed Heba Abdelrazik , Abdel Rehim Mona Hassan
Published: February 2015

Purpose

– The purpose of this paper was to protect carbon steel from corrosion with self–aggregated, eco-friendly, water-soluble hyperbranched polyamide-ester (Hb-PAE).

Design/methodology/approach

– Hb-PAE was synthesized through bulk polycondensation reaction between maleic anhydride and di-isopropanol amine. Complete structural analysis for the obtained polymer was performed using Fourier Transfer Infra-Red Spectroscopy, 1H NMR, Thermal gravimetric analysis (TGA) and differential scanning calorimetry, and the molar mass was measured using gel permeation chromatography/refractive index. For this study, the surface activity of Hb-PAE with hydroxyl end groups was investigated. Surface tension of 1.0 × 10−6 to 0.1M of both Hb-PAE/H2O and Hb-PAE/1N HCl systems was measured, and the critical aggregation concentration (CAC) in both systems was determined. Hb-PAE was examined as a corrosion inhibitor for plain carbon steel in both neutral (distilled water) and acidic (1N HCl) media. The corrosion of the steel was studied quantitatively by measuring its weight loss in both media in the absence and presence of Hb-PAE. The surface morphology of the exposed steel test samples was examined using scanning electron microscopy.

Findings

– It was found that Hb-PAE inhibited corrosion of steel around the CAC, and its corrosion inhibition efficiency was increased by increasing its concentration.

Originality/value

– The research can provide a reference for the relationship between the aggregation concentration of the prepared Hb-PAE with its corrosion inhibition efficiency on plain carbon steel. Hb-PAE as a corrosion inhibitor is environmentally acceptable, economical and readily available.
Numerical modeling and experimental investigation of fiber diameter of melt blowing nonwoven web
Authors: Zhao Bo
Published: February 2015

Purpose

– The purpose of this paper is to varify, the air drawing model and the air jet flow field model of dual slot shape die for a polymer in a melt blowing process were established, by the experimental results obtained with experimental equipment.

Design/methodology/approach

– The air jet flow field model is solved by introducing the finite difference method. The air drawing model of polymers in the melt blowing process was studied with the help of the simulation results of the air jet flow field.

Findings

– The higher air initial velocity and air initial temperature can all yield finer fibers and causes the fibers to be attenuated to a greater extent.

Originality/value

– The predicted fiber diameter agrees well with the experimental result, which verifies the reliability of these models. At the same time, the results also reveal the great potential of this research for the computer-assisted design of melt blowing technology.