bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous Estimation of Ocean Tides and Underwater Topography in the Weddell Sea
Authors: Zaron Edward D.
Published: April 2019

A new model for the M2, S2, K1, and O1 tides in the Weddell Sea is developed by assimilating CryoSat‐2 data into a barotropic tide model. A variational approach is used, which explicitly allows for errors in the water depth, that is, the bottom topography in open water and the water column thickness under floating ice shelves, so that an optimized estimate of the topography is obtained together with the tidal fields. In preparation for assimilation, the sensitivity of the tidal elevation to the interfacial drag at the sea floor and the ice‐water interface (under the floating ice shelves) is investigated; this motivates the development of a new drag parameterization which is more accurate and physically plausible in comparison with the interfacial drag alone. The assimilation of CryoSat‐2 data into the model results in tidal elevations with essentially the same accuracy as previous estimates, which is demonstrated by comparisons with independent in situ data and withheld CryoSat‐2 data. The novelty of the present tidal estimates is that they are consistent with well‐defined dynamics based on the Laplace Tidal Equations—augmented with the new parameterization of drag—and modifications of the prior estimate of underwater topography and water column thickness. Analysis of the sensitivity to the topography finds that, at this level of precision, the topography is not uniquely determined by the observed data.
Author Correction: The interplay between membrane lipids and phospholipase A family members in grapevine resistance against Plasmopara viticola
Authors: Laureano Gonçalo , Figueiredo Joana , Cavaco Ana Rita , Duarte Bernardo , Caçador Isabel , Malhó Rui , Sousa Silva Marta , Matos Ana Rita , Figueiredo Andreia
Published: April 2019

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
Heart sound signals can be used for emotion recognition
Authors: Xiefeng Cheng , Wang Yue , Dai Shicheng , Zhao Pengjun , Liu Qifa
Published: April 2019

This article studies whether heart sound signals can be used for emotion recognition. First, we built a small emotion heart sound database, and simultaneously recorded the participants’ ECG for comparative analysis. Second, according to the characteristics of the heart sound signals, two emotion evaluation indicators were proposed: HRV of heart sounds (difference between successive heartbeats) and DSV of heart sounds (the ratio of diastolic to systolic duration variability). Then, we extracted linear and nonlinear features from two emotion evaluation indicators to recognize four kinds of emotions. Moreover, we used valence dimension, arousal dimension and valence-arousal synthesis as evaluation standards. The experimental results demonstrated that heart sound signals can be used for emotion recognition. It was more effective to achieve recognition results by combining the features of HRV and DSV of heart sounds. Finally, the average accuracy of four emotion recognitions on valence dimension, arousal dimension and valence-arousal synthesis was up to 96.875%, 88.5417% and 81.25%, respectively.
Dissociated vacancies and screw dislocations in MgO and UO2: atomistic modeling and linear elasticity analysis
Authors: Liu Xiang-Yang , Martinez Enrique , Uberuaga Blas P.
Published: April 2019

Understanding the effect of dislocations on the mass transport in ionic ceramics is important for understanding the behavior of these materials in a variety of contexts. In particular, the dissociated nature of vacancies at screw dislocations, or more generally, at a wide range of low-angle twist grain-boundaries, has ramifications for the mechanism of defect migration and thus mass transport at these microstructural features. In this paper, a systematic study of the dissociated vacancies at screw dislocations in MgO is carried out. The important role of stress migration in the atomistic modeling study is identified. Another aspect of the current work is a rigorous treatment of the linear elasticity model. As a result, good agreement between the atomistic modeling results and the linear elasticity model is obtained. Furthermore, we demonstrate that the proposed vacancy dissociation mechanism can also be extended to more complicated ionic ceramics such as UO2, highlighting the generality of the mechanism.
Temporal-order information can be maintained in non-conscious working memory
Authors: Trübutschek Darinka , Marti Sébastien , Dehaene Stanislas
Published: April 2019

Classical theories hold conscious perception and working memory to be tightly interwoven. Recent work has challenged this assumption, demonstrating that information may be stored for several seconds without any subjective awareness. Does such non-conscious working memory possess the same functional properties as conscious working memory? Here, we probe whether non-conscious working memory can maintain multiple items and their temporal order. In a visual masking task with a delayed response, 38 participants were asked to retain the location and order of presentation of two sequentially flashed spatial positions, and retrieve both after a 2.5 second delay. Even when subjective visibility was nil, subjects’ objective forced-choice performance exceeded chance level and, crucially, distinct retrieval of the first and second location was observed on both conscious and non-conscious trials. Non-conscious working memory may therefore store two items in proper temporal order. These findings can be explained by recent models of activity-silent working memory.
Understanding the regulation of overwintering diapause molecular mechanisms in Culex pipiens pallens through comparative proteomics
Authors: Zhang Chongxing , Wei Dongdong , Shi Guihong , Huang Xiaoli , Cheng Peng , Liu Gongzhen , Guo Xiuxia , Liu Lijuan , Wang Huaiwei , Miao Feng , Gong Maoqing
Published: April 2019

To reveal overwintering dormancy (diapause) mechanisms of Culex pipiens pallens (L.), global protein expression differences at three separate time points represent nondiapause, diapause preparation and overwintering diapause phases of Cx. pipiens pallens were compared using iTRAQ. Cx. pipiens pallens females accumulate more lipid droplets during diapause preparation and overwintering diapause maintenance than during the nondiapause phase. A total of 1030 proteins were identified, among which 1020 were quantified and compared. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), Domain and Clusters of Orthologous Groups (COG) analyses revealed key groups of proteins, pathways and domains differentially regulated during diapause preparation and overwintering diapause maintenance phases in this mosquito, including major shifts in energy production and conversion, fatty acid metabolism, the citrate (TCA) cycle, and the cytoskeletal reorganization pathway. Our results provide novel insight into the molecular bases of diapause in mosquitoes and corroborate previously reported diapause-associated features in invertebrates. More interestingly, the phototransduction pathway exists in Cx. pipiens pallens, in particular, actin, rather than other proteins, appears to have substantial role in diapause regulation. In addition, the differential changes in calmodulin protein expression in each stage implicate its important regulatory role of the Cx. pipiens pallens biological clock. Finally, 24 proteins were selected for verification of differential expression using a parallel reaction monitoring strategy. The findings of this study provide a unique opportunity to explore the molecular modifications underlying diapause in mosquitoes and might therefore enable the future design and development of novel genetic tools for improving management strategies in mosquitoes.
Glucagon reduces airway hyperreactivity, inflammation, and remodeling induced by ovalbumin
Authors: Insuela Daniella B. R. , Azevedo Carolina T. , Coutinho Diego S. , Magalhães Nathalia S. , Ferrero Maximiliano R. , Ferreira Tatiana Paula T. , Cascabulho Cynthia M. , Henriques-Pons Andrea , Olsen Priscilla C. , Diaz Bruno L. , Silva Patricia M. R. , Cordeiro Renato S. B. , Martins Marco A. , Carvalho Vinicius F.
Published: April 2019

Glucagon has been shown to be beneficial as a treatment for bronchospasm in asthmatics. Here, we investigate if glucagon would prevent airway hyperreactivity (AHR), lung inflammation, and remodeling in a murine model of asthma. Glucagon (10 and 100 µg/Kg, i.n.) significantly prevented AHR and eosinophilia in BAL and peribronchiolar region induced by ovalbumin (OVA) challenge, while only the dose of 100 µg/Kg of glucagon inhibited subepithelial fibrosis and T lymphocytes accumulation in BAL and lung. The inhibitory action of glucagon occurred in parallel with reduction of OVA-induced generation of IL-4, IL-5, IL-13, TNF-α, eotaxin-1/CCL11, and eotaxin-2/CCL24 but not MDC/CCL22 and TARC/CCL17. The inhibitory effect of glucagon (100 µg/Kg, i.n.) on OVA-induced AHR and collagen deposition was reversed by pre-treatment with indomethacin (10 mg/Kg, i.p.). Glucagon increased intracellular cAMP levels and inhibits anti-CD3 plus anti-CD28-induced proliferation and production of IL-2, IL-4, IL-10, and TNF- α from TCD4+ cells in vitro. These findings suggest that glucagon reduces crucial features of asthma, including AHR, lung inflammation, and remodeling, in a mechanism probably associated with inhibition of eosinophils accumulation and TCD4+ cell proliferation and function. Glucagon should be further investigated as an option for asthma therapy.
Reactive silica nanoparticles turn epoxy coating from hydrophilic to super-robust superhydrophobic
Authors: Zhi Danfeng , Wang Huanhuan , Jiang Dong , Parkin Ivan P. , Zhang Xia
Published: April 2019

Superhydrophobic organic–inorganic hybrid nanocomposite coatings have received much attention because they possess the advantages of both inorganic and organic materials.
Polydiaminoanthraquinones with tunable redox properties as high performance organic cathodes for K-ion batteries
Authors: Zhou Min , Liu Mengyun , Wang Juan , Gu Tiantian , Huang Bing , Wang Wei , Wang Kangli , Cheng Shijie , Jiang Kai
Published: April 2019

Polydiaminoanthraquinones with redox-active quinone-based segments linked by polyanilines were developed as advanced K storage cathodes with tunable redox properties.
Pressure-dependent guest binding and release on a supramolecular polymer
Authors: Yonezawa Shumpei , Sethy Ramarani , Fukuhara Gaku , Kawai Tsuyoshi , Nakashima Takuya
Published: April 2019

Pressurization on a supramolecular host–guest system induces the compression of binding pockets, discharging the guest molecules.
Periodic symmetry defined bioreactors enhance algae growth
Authors: Tseng Yen-Hsun , Lee Tyler I. , Doane Samuel J. , Butterfield Anthony E. , McLennan John D. , Mohanty Swomitra K. , Pease Leonard F.
Published: April 2019

Modular photobioreactors present a more efficient and cost-effective pathway to scale up algae production to commercially relevant acreage.
Annulated bacteriochlorins for near-infrared photophysical studies
Authors: Fujita Hikaru , Jing Haoyu , Krayer Michael , Allu Srinivasarao , Veeraraghavaiah Gorre , Wu Zhiyuan , Jiang Jianbing , Diers James R. , Magdaong Nikki Cecil M. , Mandal Amit K. , Roy Arpita , Niedzwiedzki Dariusz M. , Kirmaier Christine , Bocian David F. , Holten Dewey , Lindsey Jonathan S.
Published: April 2019

Bacteriochlorins with phenaleno or benzo annulation absorb at 913 or 1033 nm and exhibit excited-state lifetimes of 150 or 7 ps, suggesting applications in photoacoustic imaging.
Structural origin of the high-performance light-emitting InGaN/AlGaN quantum disks
Authors: Cheng Shaobo , Langelier Brian , Ra Yong-Ho , Rashid Roksana Tonny , Mi Zetian , Botton Gianluigi A.
Published: April 2019

3D model showing the boomerang shape of the InGaN/AlGaN quantum disks.
Remote heteroepitaxy of atomic layered hafnium disulfide on sapphire through hexagonal boron nitride
Authors: Wang Denggui , Lu Yong , Meng Junhua , Zhang Xingwang , Yin Zhigang , Gao Menglei , Wang Ye , Cheng Likun , You Jingbi , Zhang Jicai
Published: April 2019

Remote heteroepitaxy of single-crystal HfS2 on sapphire through h-BN is first realized and can be extended to other 2D heterostructures.
Fabrication of biocleavable crosslinked polyprodrug vesicles via reversible donor–acceptor interactions for enhanced anticancer drug delivery
Authors: Zhang Xiaolong , Hua Qi , Meng Ping , Wang Mingqi , Wang Yunfei , Sun Lu , Ma Liwei , Wang Baoyan , Yu Cuiyun , Wei Hua
Published: April 2019

Reversible donor–acceptor interactions were used to prepare biocleavable crosslinked polyprodrug vesicles toward enhanced anticancer drug delivery.
Thermally-driven mesopore formation and oxygen release in delithiated NCA cathode particles
Authors: Besli Münir M. , Shukla Alpesh Khushalchand , Wei Chenxi , Metzger Michael , Alvarado Judith , Boell Julian , Nordlund Dennis , Schneider Gerhard , Hellstrom Sondra , Johnston Christina , Christensen Jake , Doeff Marca M. , Liu Yijin , Kuppan Saravanan
Published: April 2019

The structural integrity of layered Ni-rich oxide cathode materials is one of the most essential factors that critically affect the performance and reliability of lithium-ion batteries.
Unravelling mass transport in hierarchically porous catalysts
Authors: Isaacs Mark A. , Robinson Neil , Barbero Brunella , Durndell Lee J. , Manayil Jinesh C. , Parlett Christopher M. A. , D'Agostino Carmine , Wilson Karen , Lee Adam F.
Published: April 2019

Hierarchical porous catalysts offer highly connected architectures for enhanced transport of bulky molecules and the sustainable manufacturing of bio-derived platform chemicals and fuels.
A CoHCF system with enhanced energy conversion efficiency for low-grade heat harvesting
Authors: Jiang Jing , Tian Hanqing , He Xinrui , Zeng Qing , Niu Yi , Zhou Ting , Yang Yuan , Wang Chao
Published: April 2019

Cobalt hexacyanoferrate (CoHCF) materials were used for TRECs; when complexed with HCNTs they show higher heat-to-electricity conversion efficiency.
Confined annealing-induced transformation of tin oxide into sulfide for sodium storage applications
Authors: Yang Xuming , Xiao Fengping , Wang Shuo , Liu Jin , Leung Michael K. H. , Yu Denis Y. W. , Rogach Andrey L.
Published: April 2019

Tin oxide/carbon is completely transformed into tin sulfide/carbon composite after a confined annealing treatment in sulfur vapor; thus, the practical capacity is drastically improved from 360 to 770 mA h g−1. This improvement is explained based on their different sodiation mechanisms.
Investigation of the self-discharge behaviors of the LiMn2O4 cathode at elevated temperatures: in situ X-ray diffraction analysis and a co-doping mitigation strategy
Authors: Tang Xiaoyu , Zhou Jie , Bai Miao , Wu Weiwei , Li Shaowen , Ma Yue
Published: April 2019

The lithium ion re-intercalated into the LiMn2O4 lattice during self-discharge.
Highly sensitive detection of antibodies in a soft bioactive three-dimensional bioorthogonal hydrogel
Authors: Randriantsilefisoa Rotsiniaina , Cuellar-Camacho José Luis , Chowdhury Mohammad Suman , Dey Pradip , Schedler Uwe , Haag Rainer
Published: April 2019

This three-dimensional detection method of antibodies offers a high sensitivity and good biomolecule stability for new biosensing devices.
Patterned flexible graphene sensor via printing and interface assembly
Authors: Xue Tangyue , Yang Huige , Shen Bin , Li Fengyu , Su Meng , Hu Xiaotian , Liu Wentao , Song Yanlin
Published: April 2019

Multiresolution integrated graphene sensor with microstructures and macropatterns realizes point recognition and wrist movement monitoring.
Interval type 2 fuzzy logic controlled advanced dynamic voltage restorer for voltage sag alleviation
Authors: Mallick Nirmalya , Mukherjee Vivekananda
Published: April 2019

Utilisation of modern power electronics based equipment for grid makes the system more vulnerable and sensitive. From the consumer point of view as well as for the service providers, it is essential to maintain a good quality of power to debar from serious financial loss. Thus, in recent days, system engineers are very much concerned about its solutions to tackle the deviation of voltage waveform from its standard level and to regulate the continuity of power supply. Dynamic voltage restorer (DVR) is a typical power electronics based custom power device that has become a magnificent solution in this endeavour. In the present work, an advanced and efficacious control mechanism for DVR is aimed to develop that may provide the required amount of compensation during voltage sag. The present work utilises the suitability of adaptive interval type 2 fuzzy systems in the control domain and makes the DVR more reliable. In order to enhance the capability of present DVR performance, hybridisation of DC energy storage system is realised. An artificial neural network controlled modified bi‐directional bi‐input bi‐output DC–DC converter is also implemented in the adopted test system topology to provide simultaneous supply to the loads at different voltage levels.
Dual‐optimisation of power sources including plug‐in electric vehicles and renewable energy resources at transmission‐level system
Authors: Yao Yin , Gao David Wenzhong , Momoh James
Published: April 2019

With the growing trend of plug‐in electric vehicles (PEVs), the charging load of PEVs can have a huge impact on current transmission‐level system. In the meantime, there also comes a great potential in the optimisation aspect for both power generation economic and power transmission safety concerns. Here, a dual‐optimisation algorithm is developed to minimise the total production cost of power sources including renewable energy resources (RER) and PEV cluster. In the meantime, the overloading in transmission lines and transformers is avoided. Linear programming and DC optimal power flow (DCOPF) are separately applied to step one and step two optimisation. The simulation result from a modified IEEE 9‐bus system reveals that dual‐optimisation method successfully reduced the production cost based on a hybrid model of power grid in step one optimisation. In step two optimisation, the overloaded transmission line is detected and held at capacity limit to prevent overheating. In conclusion, in dual‐optimisation algorithm, PEVs can serve as both the energy storage device and the energy supply device. Consequently, the total production cost can be reduced, and the optimal power flow can be obtained.
Calibration method of vision measurement system for ceramic billet grinding robot
Authors: Diao Shipu , Chen Xindu , Wu Lei
Published: April 2019

The accuracy of the grinding robot's vision measurement system directly affects the machining accuracy. This study proposes a calibration method of the visual measurement system installed on the fourth joint of the ceramic billet grinding robot. This calibration method includes two steps: preliminary calibration and precise calibration. Preliminary calibration is to fit the transformation matrix between robot frame and vision measurement system frame by describing the same workpiece in different frames. In the precise calibration, the visual measurement error compensation model includes the kinematics error of the robot and the preliminary calibration error. The experimental results show that the calibration method proposed in this study can calibrate the three‐dimensional (3D) vision measurement system of the robot with high precision. Besides, the repeated measurements of the same spatial point by the vision measurement system in different poses indicate that the calibrated visual system has good detection stability. The calibration method only needs to use the laser tracker and 3D scanner to collect the coordinates of the space point to complete the calibration process, which is suitable for the industrial site.
Stellar activity and planetary atmosphere evolution in tight binary star systems
Authors: Johnstone C. P. , Pilat-Lohinger E. , Lüftinger T. , Güdel M. , Stökl A.
Published: April 2019

Context. In tight binary star systems, tidal interactions can significantly influence the rotational and orbital evolution of both stars, and therefore their activity evolution. This can have strong effects on the atmospheric evolution of planets that are orbiting the two stars.

Aims. In this paper, we aim to study the evolution of stellar rotation and of X-ray and ultraviolet (XUV) radiation in tight binary systems consisting of two solar mass stars and use our results to study planetary atmosphere evolution in the habitable zones of these systems.

Methods. We have applied a rotation model developed for single stars to binary systems, taking into account the effects of tidal interactions on the rotational and orbital evolution of both stars. We used empirical rotation-activity relations to predict XUV evolution tracks for the stars, which we used to model hydrodynamic escape of hydrogen dominated atmospheres.

Results. When significant, tidal interactions increase the total amount of XUV energy emitted, and in the most extreme cases by up to factor of ~50. We find that in the systems that we study, habitable zone planets with masses of 1 M⊕ can lose huge hydrogen atmospheres due to the extended high levels of XUV emission, and the time that is needed to lose these atmospheres depends on the binary orbital separation. For some orbital separations, and when the stars are born as rapid rotators, it is also possible for tidal interactions to protect atmospheres from erosion by quickly spinning down the stars. For very small orbital separations, the loss of orbital angular momentum by stellar winds causes the two stars to merge. We suggest that the merging of the two stars could cause previously frozen planets to become habitable due to the habitable zone boundaries moving outwards.
The XXL Survey
Authors: Butler Andrew , Huynh Minh , Kapińska Anna , Delvecchio Ivan , Smolčić Vernesa , Chiappetti Lucio , Koulouridis Elias , Pierre Marguerite
Published: April 2019

The evolution of the comoving kinetic luminosity densities (Ωkin) of the radio loud high-excitation radio galaxies (RL HERGs) and the low-excitation radio galaxies (LERGs) in the ultimate XMM extragalactic survey south (XXL-S) field is presented. The wide area and deep radio and optical data of XXL-S have allowed the construction of the radio luminosity functions (RLFs) of the RL HERGs and LERGs across a wide range in radio luminosity out to high redshift (z = 1.3). The LERG RLFs display weak evolution: Φ(z)∝(1 + z)0.67 ± 0.17 in the pure density evolution (PDE) case and Φ(z)∝(1 + z)0.84 ± 0.31 in the pure luminosity evolution (PLE) case. The RL HERG RLFs demonstrate stronger evolution than the LERGs: Φ(z)∝(1 + z)1.81 ± 0.15 for PDE and Φ(z)∝(1 + z)3.19 ± 0.29 for PLE. Using a scaling relation to convert the 1.4 GHz radio luminosities into kinetic luminosities, the evolution of Ωkin was calculated for the RL HERGs and LERGs and compared to the predictions from various simulations. The prediction for the evolution of radio mode feedback in the Semi-Analytic Galaxy Evolution (SAGE) model is consistent with the Ωkin evolution for all XXL-S RL AGN (all RL HERGs and LERGs), indicating that the kinetic luminosities of RL AGN may be able to balance the radiative cooling of the hot phase of the IGM. Simulations that predict the Ωkin evolution of LERG equivalent populations show similar slopes to the XXL-S LERG evolution, suggesting that observations of LERGs are well described by models of SMBHs that slowly accrete hot gas. On the other hand, models of RL HERG equivalent populations differ in their predictions. While LERGs dominate the kinetic luminosity output of RL AGN at all redshifts, the evolution of the RL HERGs in XXL-S is weaker compared to what other studies have found. This implies that radio mode feedback from RL HERGs is more prominent at lower redshifts than was previously thought.
Production inventory model for controllable deterioration rate with shortages
Authors: Mishra Umakanta , Tijerina-Aguilera Jacobo , Tiwari Sunil , Cárdenas-Barrón Leopoldo Eduardo
Published: April 2019

This paper deals with an economic production quantity (EPQ) inventory model for deteriorating items under preservation technology. The preservation technology is used to protect the items from deterioration. Three different production levels are considered. It is assumed that initially the production rate is at a lower rate and it increases gradually over the period. This is just in order to reduce the holding cost by avoiding the larger stock quantity at the beginning of the production cycle. The shortages are permitted and fully backordered. The objective of the production inventory model is to determine the optimal production policy which minimizes the manufacturer’s total cost. Theoretical results are established in order to demonstrate the existence of the optimal solution and a proper solution procedure is presented. A numerical example and sensitivity analysis are presented to validate the theoretical results. Also, some managerial insights are provided.
Silver Triflate Catalyzed Synthesis of Isoquinolino[2,1-a]quinazo­lino[3,2-c]quinazoline Derivatives via Alkyne Hydroamination
Authors: Pan Wan-Chen , Zhang Mei-Mei , Liu Jian-Quan , Wang Xiang-Shan
Published: April 2019

Using 2-(2-aminophenyl)quinazolin-4(3H)-one and 2-(2-phenylethynyl)benzaldehyde as the reactants, silver triflate (AgOTf) was proved to be an efficient catalyst to promote not only quinazoline cyclization, but also the intramolecular hydroamination of alkyne for the synthesis of 6-aryl-17H,18aH-isoquinolino[2,1-a]quinazolino[3,2-c]quinazolin-17-one derivatives in high yields.
Synthesis of Diarylacetylenes Bearing Electron-Withdrawing Groups via the Smiles Rearrangement
Authors: Bujok Robert , Mąkosza Mieczysław
Published: April 2019

Nitrobenzyl benzothiazol-2-yl sulfones and nitrobenzyl 1-phenyl-1H-tetrazol-5-yl sulfones react with chlorides of aromatic acids to form β-acyl derivatives. These products undergo the Smiles rearrangement resulting in the formation of the corresponding nitrophenyl arylacetylenes in 50–60% overall yields (approx. 75% per step). Sulfones bearing CF3 or CN groups instead of a NO2 substituent form mixtures of the acetylenes in moderate yields and benzyl aryl ketones in yields above 40%.
Digital Subtraction Neuroangiography: What a Resident Should Know
Authors: Neelakantan Sankar , Samant Rohan , Prasad Jagadish , Reddy Bhavana , Reddy Prashanth , Das Bharath , Viswamitra Sanjaya , Mohan Dilip
Published: April 2019

Neuroangiography (NA) is an integral investigation in the management of patients with neurovascular diseases. NA is basically used for diagnosis, but in many instances, it may be followed up with treatment in the same sitting. Indications for diagnostic NA range from extracranial diseases (vertebra-basilar insufficiency from subclavian steal, extracranial carotid stenosis, cavernous-carotid fistula, neck trauma, epistaxis, etc.) to intracranial diseases (nontraumatic subarachnoid hemorrhage, cerebral aneurysms, cerebral arteriovenous malformations, cerebral vasospasm, acute stroke, etc.). A sound understanding of the principles of appropriate periprocedural care and anatomy, catheter technique, and basic disease pathology are vital for the test to be diagnostic. This pictorial review illustrates normal neurovascular anatomy along with an approach to analyze a spectrum of neurovascular pathologies and also explains a step-wise checklist for appropriate preprocedural assessment, technique of procedure, and postprocedural care of the patient. Basic knowledge on how to interpret these images and principles on how to perform it is important.
Electron emission produced by strong field laser radiation
Authors: Rokhlenko A.
Published: April 2019

The well-established Fowler-Nordheim-Schottky field emission theory is modified for strong electric fields E produced by pulsed laser radiation. The derivation of the electron tunneling probability through the triangular potential barrier is re-examined and simplified for an effective solution. This probability is studied only for strong fields, when the wavelength of the electrons is much larger than the barrier width. It is calculated for ten channels of electron emission; the emission decreases very sharply for channels with high numbers.
Statistical mechanics of transport processes in active fluids. II. Equations of hydrodynamics for active Brownian particles
Authors: Epstein Jeffrey M. , Klymko Katherine , Mandadapu Kranthi K.
Published: April 2019

We perform a coarse-graining analysis of the paradigmatic active matter model, active Brownian particles, yielding a continuum description in terms of balance laws for mass, linear and angular momentum, and energy. The derivation of the balance of linear momentum reveals that the active force manifests itself directly as a continuum-level body force proportional to an order parameter-like director field, which therefore requires its own evolution equation to complete the continuum description of the system. We derive this equation, demonstrating in the process that bulk currents may be sustained in homogeneous systems only in the presence of interparticle aligning interactions. Furthermore, we perform a second coarse-graining of the balance of linear momentum and derive the expression for active or swim pressure in the case of mechanical equilibrium.
Increasing the signal-to-noise ratio of magnetic tunnel junctions by cryogenic preamplification
Authors: Dark J. , Ying H. , Nunn G. , Cressler J. D. , Davidović D.
Published: April 2019

Cryogenic preamplification using silicon–germanium heterojunction bipolar transistors has proven to be effective in increasing the signal-to-noise ratio of the tunnel magnetoresistance of high resistance magnetic tunnel junctions at 8 K. The magnetic tunnel junctions used have resistances greater than 1 MΩ, and the cryogenic measurement system still has sufficient bandwidth for the 1/f noise to roll off. A noise model for the system has been proposed and evaluated experimentally. The noise temperature and minimum noise temperature of the transistor used in the experiment are calculated and compared. The signal-to-noise ratio of the junction alone and the transistor-junction system is derived from the sample and circuit parameters and compared. Experimental data show a signal-to-noise ratio increase by a factor of 6.62 after adding in the cryogenic preamplifier. An increase in 1/f noise in the antiparallel state of the tunneling junction as opposed to the parallel state is also observed giving evidence of 1/f noise dependence on the magnetic state of the junction.
Hypervelocity cluster ion impacts on free standing graphene: Experiment, theory, and applications
Authors: Verkhoturov Stanislav V. , Gołuński Mikołaj , Verkhoturov Dmitriy S. , Czerwinski Bartlomiej , Eller Michael J. , Geng Sheng , Postawa Zbigniew , Schweikert Emile A.
Published: April 2019

We present results from experiments and molecular dynamics (MD) simulations obtained with C60 and Au400 impacting on free-standing graphene, graphene oxide (GO), and graphene-supported molecular layers. The experiments were run on custom-built ToF reflectron mass spectrometers with C60 and Au-LMIS sources with acceleration potentials generating 50 keV C602+ and 440–540 keV Au4004+. Bombardment-detection was in the same mode as MD simulation, i.e., a sequence of individual projectile impacts with separate collection/identification of the ejecta from each impact in either the forward (transmission) or backward (reflection) direction. For C60 impacts on single layer graphene, the secondary ion (SI) yields for C2 and C4 emitted in transmission are ∼0.1 (10%). Similar yields were observed for analyte-specific ions from submonolayer deposits of phenylalanine. MD simulations show that graphene acts as a trampoline, i.e., they can be ejected without destruction. Another topic investigated dealt with the chemical composition of free-standing GO. The elemental composition was found to be approximately COH2. We have also studied the impact of Au400 clusters on graphene. Again SI yields were high (e.g., 1.25 C−/impact). 90–100 Au atoms evaporate off the exiting projectile which experiences an energy loss of ∼72 keV. The latter is a summation of energy spent on rupturing the graphene, ejecting carbon atoms and clusters and a dipole projectile/hole interaction. The charge distribution of the exiting projectiles is ∼50% neutrals and ∼25% either negatively or positively charged. We infer that free-standing graphene enables detection of attomole to zeptomole deposits of analyte via cluster-SI mass spectrometry.
Study of optical bistability based on hybrid-cavity semiconductor lasers
Authors: Wang Fu-Li , Huang Yong-Zhen , Yang Yue-De , Ma Chun-Guang , Hao You-Zeng , Tang Min , Xiao Jin-Long
Published: April 2019

All-optical flip-flop has been demonstrated experimentally based on our optical bistable hybrid square-rectangular lasers. In this paper, dual-mode rate equations are utilized for studying the optical bistability in the two-section hybrid-coupled semiconductor laser. A phenomenological gain spectrum model is constructed for considering the mode competition in gain section and saturable absorption effect in the absorptive section in a wide wavelength range. The mechanisms of the optical bistability are verified in the aspect of the distribution of carriers and photons in the two-section hybrid-coupled cavity. In addition, we find that with the adjustment of the device parameters, both of the width and biasing current for achieving the bistability can be tuned for a wide range. Furthermore, a dynamic response of all-optical flip-flop is simulated, using a pair of set/reset optical triggering pulses, in order to figure out the laws for faster transition time with lower power consumption.
Calculation of the absolute photoionization cross-sections for C1–C4 Criegee intermediates and vinyl hydroperoxides
Authors: Huang Can , Yang Bin , Zhang Feng
Published: April 2019

Criegee Intermediates (CIs) and their isomer Vinyl Hydroperoxides (VHPs) are crucial intermediates in the ozonolysis of alkenes. To better understand the underlying chemistry of CIs and VHPs, progress has been made to detect and identify them by photoionization mass spectrometric experiments. Further reliable quantitative information about these elusive intermediates requires their photoionization cross sections. The present work systematically investigated the near-threshold absolute photoionization cross-sections for ten C1–C4 CIs and VHPs, i.e., formaldehyde oxide (CH2OO), acetaldehyde oxide (syn-/anti-CH3CHOO), acetone oxide ((CH3)2COO), syn-CH3-anti-(cis-CH=CH2)COO, syn-CH3-anti-(trans-CH=CH2)COO and vinyl hydroperoxide (CH2CHOOH), 2-hydroperoxypropene (CH2=C(CH3)OOH), syn-CH2 = anti-(cis-CH=CH2)-COOH, syn-CH2 = anti-(trans-CH=CH2)COOH. The adiabatic ionization energies (AIEs) were calculated at the DLPNO-CCSD(T)/CBS level with uncertainties of less than 0.05 eV. The calculated AIEs for C1–C4 CIs and VHPs vary from 8.75 to 10.0 eV with the AIEs decreasing as the substitutions increase. Franck-Condon factors were calculated with the double Duschinsky approximation and the ionization spectra were obtained based on the calculated ionization energies. Pure electronic photoionization cross sections are calculated by the frozen-core Hartree–Fock (FCHF) approximation. The final determined absolute cross sections are around 4.5–6 Mb for the first and second ionization of CIs and 15–25 Mb for VHPs. It is found that the addition of a methyl group or an unsaturated vinyl substitution for the CIs does not substantially change the absolute value of their cross sections.
Human photoplethysmogram through the Morse graph: Searching for the saddle point in experimental data
Authors: Miyaji Tomoyuki , Sviridova Nina , Aihara Kazuyuki , Zhao Tiejun , Nakano Akimasa
Published: April 2019

Photoplethysmogram (PPG) is one of the noninvasive biological signals widely used for the estimation of physiological parameters, such as heart rates in human health monitoring. Methods of its processing, its applications, and dynamics have been extensively investigated over the last several decades. However, there is still lack of the knowledge related to the fundamental structure of the PPG dynamics such as saddle equilibrium points, which have crucial importance to achieve the full understanding of the PPG dynamics and might provide useful information for establishing a mathematical model of the PPG. In this study, Morse graph theory was applied to the experimental PPG data in an attempt to verify the existence of saddle equilibrium and estimate its location with respect to the time-delay-reconstructed PPG attractor. The results demonstrated evidence that a saddle equilibrium point can be found in a neighborhood of the reconstructed PPG trajectory; moreover, it was found to be in the same reconstructed attractor’s region for healthy subjects from different age groups that points toward fundamental importance of the found saddle equilibrium for a general understanding of the PPG dynamics.
On the electronically nonadiabatic decomposition dynamics of furazan and triazole energetic molecules
Authors: Ghosh Jayanta , Gajapathy Harshad , Jayachandran Ajay , Bernstein Elliot R. , Bhattacharya Atanu
Published: April 2019

The combined results of ab initio electronic-structure calculations, nonadiabatic molecular dynamics simulations using ab initio multiple spawning, and previous spectroscopic investigations of jet-cooled molecules provide strong evidence of a (π,σ*)-mediated decomposition mechanism for the furazan and triazole energetic molecules. The importance of dissociative excited states formed by electron promotion from a π molecular orbital to a σ* molecular orbital is explored for the furazan and triazole energetic molecules. Dissociative (π,σ*) states of furazan and triazole energetic molecules can be populated by nonadiabatic surface jump from the (π,π*) or the (n,π*) state. Finally, conical intersections between (π,σ*) potential energy surfaces (PESs) and the ground PES influence the eventual fragmentation dynamics of the furazan and triazole energetic molecules. Due to structural similarity of the triazole molecule with the pyrrole molecule, a comparison of nonadiabatic dynamics of these two molecules is also presented. The N–N bond dissociation is found to be a barrierless pathway for the triazole molecule, whereas the N–H bond dissociation exhibits a barrierless pathway for the pyrrole molecule. The present work, thus, provides insights into the excited-state chemistry of furazan and triazole energetic functional groups. The same insight can also be relevant for other energetic molecules.
Influence of p- and n-type doping gases on nanoparticle formation in SiH4/H2 radiofrequency plasma discharges used for polymorphous silicon thin film deposition
Authors: Kharchenko A. V. , Ouaras K. , Suendo V. , Ebothé J. , Roca i Cabarrocas P.
Published: April 2019

We study the effect of the addition of p- or n-type doping gases, trimethylboron (TMB) or phosphine, respectively, on cluster formation in the SiH4/H2 plasma used for the deposition of hydrogenated polymorphous silicon thin films. The formation of clusters is monitored using time-resolved measurements of the second harmonic of the radio frequency current J2. We show that the addition of PH3 does not change the cluster formation, while the addition of a small amount of trimethylboron strongly affects its charging behavior, preventing to some extent its agglomeration. The most ordered pm-Si:H thin films are obtained under conditions from which not only clusters but also larger silicon agglomerates are formed in the plasma and contribute to the deposition. The inhibiting role of TMB on the agglomeration and powder formation is evidenced by the smoothness of p-type films at high rates, as deduced from the sample surface topography obtained by atomic force microscopy measurements.
Relativistic proton emission from ultrahigh-energy-density nanosphere generated by microbubble implosion
Authors: Murakami M. , Arefiev A. , Zosa M. A. , Koga J. K. , Nakamiya Y.
Published: April 2019

Laser intensity scalings are investigated for accelerated proton energy and attainable electrostatic field using microbubble implosion (MBI). In MBI, the bubble wall protons are subject to volumetric acceleration toward the center due to the spherically symmetric electrostatic force generated by hot electrons filling the bubble. Such an implosion can generate an ultrahigh density proton core of nanometer size on the collapse, which results in an ultrahigh electrostatic field to emit energetic protons in the relativistic regime. Three-dimensional particle-in-cell and molecular dynamics simulations are conducted in a complementary manner. As a result, underlying physics of MBI are revealed such as bubble-pulsation and ultrahigh energy densities, which are higher by orders of magnitude than, for example, those expected in a fusion-igniting core of inertially confined plasma. MBI has potential as a plasma-optical device, which optimally amplifies an applied laser intensity by a factor of two orders of magnitude; thus, MBI is proposed to be a novel approach to the Schwinger limit.
Telomere DNA G-quadruplex folding within actively extending human telomerase
Authors: Jansson Linnea I. , Hentschel Jendrik , Parks Joseph W. , Chang Terren R. , Lu Cheng , Baral Rishika , Bagshaw Clive R. , Stone Michael D.
Published: April 2019

Significance

Telomeres protect the ends of linear chromosomes from illicit DNA processing events that threaten genome stability. Guanine-rich telomere DNA repeat sequences are protected by telomere-binding proteins, and are also prone to fold into structures called G quadruplexes (GQs). In highly proliferative cells, including the majority of human cancers, telomeres are maintained by the telomerase enzyme. Thus, telomerase and its telomere DNA substrates represent important targets for developing novel cancer drugs. The results of this study suggest GQ folding of newly synthesized DNA may occur within an actively extending telomerase enzyme. Our experiments highlight the importance of telomere DNA structure during the function of telomerase and its associated telomere-binding proteins.
Cystine–glutamate antiporter xCT deficiency suppresses tumor growth while preserving antitumor immunity
Authors: Arensman Michael D. , Yang Xiaoran S. , Leahy Danielle M. , Toral-Barza Lourdes , Mileski Mary , Rosfjord Edward C. , Wang Fang , Deng Shibing , Myers Jeremy S. , Abraham Robert T. , Eng Christina H.
Published: April 2019

Significance

xCT, the cystine–glutamate antiporter, has been implicated in supporting both tumor growth and T cell proliferation; thus, antitumor effects of systemic xCT inhibition may be blunted by compromised antitumor immunity. This report details the unexpected finding that xCT is dispensable for T cell proliferation in vivo and for antitumor immune responses. Consequently, tumor cell xCT loss acts synergistically with the immunotherapeutic agent anti–CTLA-4, laying the foundation for utilizing specific xCT inhibitors clinically to expand the efficacy of existing anticancer immunotherapeutics.
Frequency of DNA end joining
in trans
is not determined by the predamage spatial proximity of double-strand breaks in yeast
Authors: Sunder Sham , Wilson Thomas E.
Published: April 2019

Significance

DNA double-strand breaks (DSBs) are severe insults that lead to different types of genome rearrangements if repaired incorrectly. We explored the genesis of genomic rearrangements mediated by the nonhomologous end-joining pathway of DSB repair. Previous studies suggested that the efficiency of
trans
repair (i.e., rearrangements) is strongly influenced by the distance between two stretches of DNA incurring DSBs. We systematically investigated the impact of predamage spatial proximity on
trans
repair frequency in yeast and found no correlation between them, which has important implications for understanding chromosome movement and disease-causing rearrangements.
Foam as a self-assembling amorphous photonic band gap material
Authors: Ricouvier Joshua , Tabeling Patrick , Yazhgur Pavel
Published: April 2019

Significance

Recently discovered disordered materials with complete photonic band gap can enable the production of freeform wave guides, energy-efficient displays, or iridescent ultraresistant pigments. Surprisingly, the fabrication of such amorphous photonic materials is completely dominated by the top-down approach and suffers from its severe limitations (cost, timescale, defects, resolution, etc.). Here, we present a class of photonic band gap materials—“photonic foams”—that can be fabricated by self-assembly. We demonstrate that 2D photonic foams possess a large isotropic photonic band gap and discuss a pathway toward 3D structures.
Accumulation of PNPLA3 on lipid droplets is the basis of associated hepatic steatosis
Authors: BasuRay Soumik , Wang Yang , Smagris Eriks , Cohen Jonathan C. , Hobbs Helen H.
Published: April 2019

Significance

A sequence variant (I148M) in PNPLA3 is a major genetic risk factor for nonalcoholic fatty liver disease. Previously, we showed that PNPLA3(148M) evades ubiquitylation-mediated degradation and accumulates to high levels on lipid droplets (LDs). Here we address how this accumulation is related to steatosis. We generated an active, ubiquitylation-resistant isoform that accumulated on LDs and increased hepatic triglyceride levels when expressed in livers of mice. Conversely, depletion of PNPLA3 resolved the excess hepatic fat accumulation associated with expression of PNPLA3(148M). Our results provide direct evidence that accumulation of PNPLA3 per se causes fatty liver, and that depletion of the protein is a potential strategy for therapeutic intervention.
Radio frequency transmitter based on a laser frequency comb
Authors: Piccardo Marco , Tamagnone Michele , Schwarz Benedikt , Chevalier Paul , Rubin Noah A. , Wang Yongrui , Wang Christine A. , Connors Michael K. , McNulty Daniel , Belyanin Alexey , Capasso Federico
Published: April 2019

Significance

Semiconductor lasers are compact sources of coherent light. When operating in an optical frequency comb regime, they can generate a spectrum consisting of discrete frequency lines that are equally spaced. Most frequency comb applications, such as spectroscopy and metrology, directly use the optical output of these lasers. In microwave photonics applications, the frequency comb output is sent to a fast photodetector and used to produce microwaves. Here, we propose to integrate laser, detector, and antenna in the same device. We show that, in addition to generating microwaves, a properly designed laser can emit microwaves wirelessly and modulate them with a signal containing information. This work opens the door to a type of hybrid electronic–photonic devices.