bluuebunny/crossref_metadata_2025 huggingface dataset:
Disruption of the structural and functional features of surfactant protein A by acrolein in cigarette smoke
Authors: Takamiya Rina , Uchida Koji , Shibata Takahiro , Maeno Toshitaka , Kato Masaki , Yamaguchi Yoshiki , Ariki Shigeru , Hasegawa Yoshihiro , Saito Atsushi , Miwa Soichi , Takahashi Hiroki , Akaike Takaaki , Kuroki Yoshio , Takahashi Motoko
Published: August 2017

The extent to which defective innate immune responses contribute to chronic obstructive pulmonary disease (COPD) is not fully understood. Pulmonary surfactant protein A (SP-A) plays an important role in regulating innate immunity in the lungs. In this study, we hypothesised that cigarette smoke (CS) and its component acrolein might influence pulmonary innate immunity by affecting the function of SP-A. Indeed, acrolein-modified SP-A was detected in the lungs of mice exposed to CS for 1 week. To further confirm this finding, recombinant human SP-A (hSP-A) was incubated with CS extract (CSE) or acrolein and then analysed by western blotting and nanoscale liquid chromatography-matrix-assisted laser desorption/ionisation time-of-flight tandem mass spectrometry. These analyses revealed that CSE and acrolein induced hSP-A oligomerisation and that acrolein induced the modification of six residues in hSP-A: His39, His116, Cys155, Lys180, Lys221, and Cys224. These modifications had significant effects on the innate immune functions of hSP-A. CSE- or acrolein-induced modification of hSP-A significantly decreased hSP-A’s ability to inhibit bacterial growth and to enhance macrophage phagocytosis. These findings suggest that CS-induced structural and functional defects in SP-A contribute to the dysfunctional innate immune responses observed in the lung during cigarette smoking.
Age-related changes in crowding and reading speed
Authors: Liu Rong , Patel Bhavika N. , Kwon MiYoung
Published: August 2017

Crowding, the inability to recognize objects in clutter, is known to play a role in developmental changes in reading speed. Here, we investigated whether crowding also plays a role in age-related changes in reading speed. We recruited 18 young (mean age: 22.6 ± 3.5; range: 18~31) and 21 older adults (mean age: 58.2 ± 7.0; range: 50~73) with normal vision. Reading speed was measured with short blocks of text. The degree of crowding was determined by measuring crowding zone (the distance between a target and flankers required to yield a criterion recognition accuracy) and the size of the visual span (an uncrowded window in the visual field within which letters can be recognizable reliably). Measurements were made across the central 16-degree visual field using letter-recognition tasks. Our results showed that, compared to young adults, older adults exhibited significantly slower reading speed (a decrease by 30%) and larger crowding: an enlargement of crowding zone (an increase by 31%) and shrinkage of the visual span (a decrease by 6.25 bits). We also observed significant correlations between reading speed and each of the crowding measures. Our results suggest that crowding increases with age. Age-related changes in crowding may in part explain slower reading in older adults.
Phylogeny and morphological analyses of Penicillium section Sclerotiora (Fungi) lead to the discovery of five new species
Authors: Wang Xin-Cun , Chen Kai , Zeng Zhao-Qing , Zhuang Wen-Ying
Published: August 2017

Phylogeny of Penicillium section Sclerotiora is still limitedly investigated. In this study, five new species of Penicillium are identified from the samples collected from different places of China, and named P. austrosinicum, P. choerospondiatis, P. exsudans, P. sanshaense and P. verrucisporum. The conidiophores of P. austrosinicum and P. exsudans are monoverticillate like most members of the section, while the rest species are biverticillate similar to the only two species P. herquei and P. malachiteum previously reported in the section Sclerotiora. The phylogenetic positions of the new taxa are determined based on the sequence data of ITS, BenA, CaM and RPB2 regions, which reveals that all the species with biverticillate condiophores form a well-supported subclade in the section. The new Penicillium species clearly differ from the existing species of the genus in culture characteristics on four standard growth media, microscopic features, and sequence data. Morphological discrepancies are discussed between the new species and their allies.
Identification, synthesis and biological activity of alkyl-guanidine oligomers as potent antibacterial agents
Authors: Zamperini C. , Maccari G. , Deodato D. , Pasero C. , D’Agostino I. , Orofino F. , De Luca F. , Dreassi E. , Docquier J. D. , Botta M.
Published: August 2017

In the last two decades, the repertoire of clinically effective antibacterials is shrinking due to the rapidly increasing of multi-drug-resistant pathogenic bacteria. New chemical classes with innovative mode of action are required to prevent a return to the pre-antibiotic era. We have recently reported the identification of a series of linear guanidine derivatives and their antibacterial properties. A batch of a promising candidate for optimization studies (compound 1) turned out to be a mixture containing two unknown species with a better biological activity than the pure compound. This serendipitous discovery led us to investigate the chemical nature of the unknown components of the mixture. Through MS analysis coupled with design and synthesis we found that the components were spontaneously generated oligomers of the original compound. Preliminary biological evaluations eventually confirmed the broad-spectrum antibacterial activity of this new family of molecules. Interestingly the symmetric dimeric derivative (2) exhibited the best profile and it was selected as lead compound for further studies.
Non-diffraction propagation of acoustic waves in a rapidly modulated stratified medium
Authors: Zhu Xing-Feng , Wei Qi , Cheng Ying , Wu Da-Jian , Liu Xiao-Jun
Published: August 2017

A rapidly modulated stratified medium with a large mass density modulation depth (LMMD) is proposed to achieve non-diffraction propagation (NDP) of acoustic waves. It is found that the NDP in LMMD medium is independent of the incident angle and can be operated in a broad-band manner. Such an NDP is robust and is unhampered by medium losses. An effective medium theory (EMT) is developed for acoustic waves propagating in the LMMD medium based on the first-principles method. The LMMD EMT is verified by using the transfer-matrix method (TMM) for both propagating and evanescent waves. Furthermore, we discuss the influence of the geometry on NDP, and finite element simulations are conducted to verify the NDP in the LMMD medium.
Amygdala-centred functional connectivity affects daily cortisol concentrations: a putative link with anxiety
Authors: Hakamata Yuko , Komi Shotaro , Moriguchi Yoshiya , Izawa Shuhei , Motomura Yuki , Sato Eisuke , Mizukami Shinya , Kim Yoshiharu , Hanakawa Takashi , Inoue Yusuke , Tagaya Hirokuni
Published: August 2017

The amygdala plays a critical role in emotion. Its functional coupling with the hippocampus and ventromedial prefrontal cortex extending to a portion of the anterior cingulate cortex (ACC) is implicated in anxiogenesis and hypothalamic-pituitary-adrenal (HPA) system regulation. However, it remains unclear how amygdala-centred functional connectivity (FC) affects anxiety and cortisol concentrations in everyday life. Here, we investigate the relationship between daily cortisol concentrations (dCOR) and amygdala-centred FC during emotional processing in forty-one healthy humans. FC analyses revealed that higher dCOR predicted strengthened amygdala-centred FC with the hippocampus and cerebellum, but inhibited FC with the supramarginal gyrus and a perigenual part of the ACC (pgACC) when processing fearful faces (vs. neutral faces). Notably, the strength of amygdala-hippocampus FC mediated the positive relationship between cortisol and anxiety, specifically when the effect of amygdala-pgACC FC, a presumptive neural indicator of emotional control, was taken into account. Individuals with diminished connectivity between the amygdala and pgACC during fear-related processing might be more vulnerable to anxiogenesis as it pertains to greater circulating cortisol levels in everyday life. Individual functional patterns of amygdala-hippocampal-pgACC connectivity might provide a key to understand the complicate link between cortisol and anxiety-related behaviors.
Electrocatalytic reduction of CO2 with CCC-NHC pincer nickel complexes
Authors: Cope James D. , Liyanage Nalaka P. , Kelley Paul J. , Denny Jason A. , Valente Edward J. , Webster Charles Edwin , Delcamp Jared H. , Hollis T. Keith
Published: August 2017

CCC-NHC pincer Ni complexes electrocatalytically reduce CO2 to CO and formate at the first reduction potential without producing or requiring molecular H2.
Faradaic processes beyond Nernst's law: density functional theory assisted modelling of partial electron delocalisation and pseudocapacitance in graphene oxides
Authors: Li Junfu , O’Shea James , Hou Xianghui , Chen George Z.
Published: August 2017

DFT studies of graphene oxide models suggest that the transfer of partially delocalised electrons does not follow Nernst's Law, but explain well the common experimental observations of pseudocapacitance.
Analysis of the vibronic structure of the trans-stilbene fluorescence and excitation spectra: the S0 and S1 PES along the CeCe and Ce–Cph torsions
Authors: Orlandi Giorgio , Garavelli Marco , Zerbetto Francesco
Published: August 2017

We analyze the highly resolved vibronic structure of the low energy (≤200 cm−1) region of the fluorescence and fluorescence excitation spectra of trans-stilbene in supersonic beams.
Hysteresis and bonding reconstruction in the pressure-induced B3–B1 phase transition of 3C-SiC
Authors: Salvadó Miguel A. , Franco R. , Pertierra Pilar , Ouahrani T. , Recio J. M.
Published: August 2017

Hysteresis cycles for the B3–B1 transformation in 3C-SiC are determined from the enthalpy barriers at different pressures.
Remarkable nonlinear optical response of excess electron compounds: theoretically designed alkali-doped aziridine M–(C2NH5)n
Authors: Li Bo , Xu Chao , Xu Xuan , Zhu Chaoyuan , Gu Feng Long
Published: August 2017

Newly theoretically designed alkali-doped aziridine M–(C2NH5)4 shows a remarkable NLO response and its first hyperpolarizability is 10 to 100 times larger than those of M@Calix[4]pyrrole.
2D graphitic-C3N4 hybridized with 1D flux-grown Na-modified K2Ti6O13 nanobelts for enhanced simulated sunlight and visible-light photocatalytic performance
Authors: Wang Qiang , Guan Shiyou , Li Bing
Published: August 2017

Novel 1D/2D hybrid Na-K2Ti6O13/g-C3N4 heterojunction photocatalysts with enhanced simulated sunlight and visible-light photocatalytic performance have been successfully fabricated using a facile mixing–calcination method.
Inhibiting grain coarsening and inducing oxygen vacancies: the roles of Mn in achieving a highly reversible conversion reaction and a long life SnO2–Mn–graphite ternary anode
Authors: Hu Renzong , Ouyang Yunpeng , Liang Tao , Tang Xin , Yuan Bin , Liu Jun , Zhang Lei , Yang Lichun , Zhu Min
Published: August 2017

Nanosized Mn additives inhibiting Sn coarsensing enable fast interdiffusion kinetics in Sn/Li2O interfaces for highly reversible conversion in lithiated SnO2.
Benign-by-design preparation of humin-based iron oxide catalytic nanocomposites
Authors: Filiciotto Layla , Balu Alina M. , Romero Antonio A. , Rodríguez-Castellón Enrique , van der Waal Jan C. , Luque Rafael
Published: August 2017

Catalytic nanocomposites can be prepared via solvent-free methodologies using biomass-derived humin by-products and iron salts, found active in the conversion of isoeugenol to vanillin.
Exploiting H-transfer as a tool for the catalytic reduction of bio-based building blocks: the gas-phase production of 2-methylfurfural using a FeVO4 catalyst
Authors: Grazia L. , Bonincontro D. , Lolli A. , Tabanelli T. , Lucarelli C. , Albonetti S. , Cavani F.
Published: August 2017

A new reductive process in the field of biomass valorisation for the sustainable production of bio-fuel additives and chemicals.
Controlling silicone-saccharide interfaces: greening silicones
Authors: Macphail Benjamin , Brook Michael A.
Published: August 2017

(Poly)saccharides crosslink silicone boronic acid polymers and stabilize the silicone oil/water interface.
Characterization of zircon reference materials via high precision U–Pb LA-MC-ICP-MS
Authors: Lana Cristiano , Farina Federico , Gerdes Axel , Alkmim Ana , Gonçalves Guilherme O. , Jardim Antonio C.
Published: August 2017

Recent improvements in laser ablation and multicollector (MC)-ICP-MS technology offer higher sensitivity, robust stability, and larger dynamic ranges.
A combustion synthesis route for magnetically separable graphene oxide–CuFe2O4–ZnO nanocomposites with enhanced solar light-mediated photocatalytic activity
Authors: Kumar Aniket , Rout Lipeeka , Achary L. Satish K. , Mohanty Sangram Keshari , Dash Priyabrat
Published: August 2017

A novel GO–CuFe2O4–ZnO ternary nanocomposite has been designed as an efficient photocatalyst for the degradation of four toxic organic pollutants.
Building with ions: towards direct write of platinum nanostructures using in situ liquid cell helium ion microscopy
Authors: Ievlev Anton V. , Jakowski Jacek , Burch Matthew J. , Iberi Vighter , Hysmith Holland , Joy David C. , Sumpter Bobby G. , Belianinov Alex , Unocic Raymond R. , Ovchinnikova Olga S.
Published: August 2017

Direct write with liquid precursor using an helium ion beam, allows fabrication of nanostructures with sub-15 nm resolution and high chemical purity.
Drastic difference between hole and electron injection through the gradient shell of CdxSeyZn1−xS1−y quantum dots
Authors: Abdellah Mohamed , Poulsen Felipe , Zhu Qiushi , Zhu Nan , Žídek Karel , Chábera Pavel , Corti Annamaria , Hansen Thorsten , Chi Qijin , Canton Sophie E. , Zheng Kaibo , Pullerits Tõnu
Published: August 2017

Ultrafast fluorescence spectroscopy was used to investigate the hole injection in CdxSeyZn1−xS1−y gradient core–shell quantum dot sensitized NiO photocathodes.
The optical response of monolayer, few-layer and bulk tungsten disulfide
Authors: Molas Maciej R. , Nogajewski Karol , Slobodeniuk Artur O. , Binder Johannes , Bartos Miroslav , Potemski Marek
Published: August 2017

We present a comprehensive optical study of thin flakes of tungsten disulfide (WS2) with thickness ranging from mono- to octalayer and in the bulk limit.
Computational assisted design of the favored composition for metallic glass formation in a Ca–Mg–Cu system
Authors: Zhao S. , Li J. H. , An S. M. , Li S. N. , Liu B. X.
Published: August 2017

Based on the constructed realistic interatomic potential, the favored compositions of the Ca–Mg–Cu metallic glass are well predicted by Monte Carlo simulations.
Fermentation of Illigera aromatica with Clonostachys rogersoniana producing novel cytotoxic menthane-type monoterpenoid dimers
Authors: Dong Jian-Wei , Cai Le , Li Xue-Jiao , Mei Rui-Feng , Wang Jia-Peng , Luo Ping , Shu Yan , Ding Zhong-Tao
Published: August 2017

Five novel menthane-type monoterpenoid dimers were isolated from non-fermented and Clonostachys rogersoniana fermented Illigera aromatica.
5,6-Di(2-fluoro-2,2-dinitroethoxy)furazano[3,4-b]pyrazine: a high performance melt-cast energetic material and its polycrystalline properties
Authors: Ma Qing , Lu Zhipeng , Liao Longyu , Huang Jinglun , Liu Dabin , Li Jinshan , Fan Guijuan
Published: August 2017

A new high-energetic and insensitive melt-cast material was synthesized, and its polycrystalline properties were characterized and theoretically investigated.
Toward improved mechanical strength, oxidative stability and proton conductivity of an aligned quadratic hybrid (SPEEK/FPAPB/Fe3O4-FGO) membrane for application in high temperature and low humidity fuel cells
Authors: Vinothkannan Mohanraj , Kim Ae Rhan , Gnana kumar G. , Yoon Jeong-Mo , Yoo Dong Jin
Published: August 2017

Fe3O4 anchored functionalized GO is applied as a magnetically active filler as well as a solid proton conductor to realize an aligned hybrid membrane electrolyte architecture with blended polymer matrix consisting of FPAPB and SPEEK.
Computer‐aided design‐based circuit model of microstrip line for terahertz interconnects technology
Authors: Awasthi Yogendra K. , Singh Himanshu , Sharma Manish , Kumari Sarita , Verma Anand K.
Published: August 2017

In this study, presented a computer‐aided design‐based circuit model which is applicable to microstrip transmission line for terahertz interconnects technology in circuit simulator. Comparison of modified Kirschning and Jansen for dispersion and modified characteristic impedance for characteristic impedance models with full‐wave electromagnetic (EM) simulator are investigated which shows < 1% deviation for w/h range 0.1 ≤ w/h ≤ 100, conductor thickness 0.001 ≤ t/h ≤ 0.2, wavelength range 8.7 μm ≤ λg ≤ 8.7 m and substrate permittivity 1.0 ≤ ɛ r ≤ 200. Modified conductor loss for conductor loss and modified dielectric loss (MDL) for dielectric loss are also investigated and compared with EM simulator, which shows deviation of < 1 dB for above said electrical and physical sets of range of parameters. Calculation of line parameters: (f, t), (f, α), R (f), L (f), C (f), G (f) by using the effect of dispersion, characteristic impedance and losses which shows < 1% deviation with experimental data available. Accuracy of the circuit model are also verified for interconnects made by aluminium (σ o = 3.7 × 107 S/m), tungsten (σ o = 1.0 × 107 S/m) and tungsten–silicide (σ o = 3.3 × 106 S/m) conductors which used in very large scale integration/ultra large scale integration (VLSI/ULSI) technology.
The limit of quantum cascade detectors: A single period device
Authors: Schwarz Benedikt , Reininger Peter , Harrer Andreas , MacFarland Donald , Detz Hermann , Andrews Aaron M. , Schrenk Werner , Strasser Gottfried
Published: August 2017

In this work, we demonstrate a 4.1 μm quantum cascade photodetector with external quantum efficiencies of 40% at 80 K and 25% at 300 K. Such high efficiencies have been made possible by using a single period active region embedded in a facet coupled low-loss dielectric ridge waveguide. This emphasizes the relevance of enhancing the optical interaction for this type of detector in a different manner from increasing the number of periods. Low noise operation was achieved by using photovoltaic operation at zero bias and an elaborate band structure design to prevent undesired scattering paths. A noise equivalent power of 10  pW/Hz and a corresponding specific detectivity of 7×107  cmHz/W at room-temperature, as well as background limited operation below 124 K with a detectivity close to an ideal photodetector, are demonstrated.
Exploiting the instability of smart structure for reconfiguration
Authors: Zhang Jiaying , Zhang Chen , Hao Lin , Nie Rui , Qiu Jinhao
Published: August 2017

Aiming to verify the concept of using heteroclinic connections to reconfigure smart structures, a multistable buckled beam with integrated Shape Memory Alloy (SMA) wires is utilized as a high fidelity model. The Shape Memory Alloy (SMA) wires are resistively heated to provide the actuation force to stabilize the unstable configuration and the transition of the beam from one unstable equilibrium condition to the other. This concept provides a means of reducing the energy requirement for transitions between configurations of the structure, which is an energy-efficient reconfiguration scheme between equal-energy unstable (but actively controlled) equilibria. This letter presents a detailed design of the system, and how the active (heated) SMA wires control the structure stay in unstable configuration and drive the structure to achieve reconfiguration. Exploiting the instability of the smart structure has significant interests in many power reduction applications, including active flow control, reconfiguration of large deployable aerospace structures, and MEMS devices.
Through-membrane electron-beam lithography for ultrathin membrane applications
Authors: Neklyudova M. , Erdamar A. K. , Vicarelli L. , Heerema S. J. , Rehfeldt T. , Pandraud G. , Kolahdouz Z. , Dekker C. , Zandbergen H. W.
Published: August 2017

We present a technique to fabricate ultrathin (down to 20 nm) uniform electron transparent windows at dedicated locations in a SiN membrane for in situ transmission electron microscopy experiments. An electron-beam (e-beam) resist is spray-coated on the backside of the membrane in a KOH-etched cavity in silicon which is patterned using through-membrane electron-beam lithography. This is a controlled way to make transparent windows in membranes, whilst the topside of the membrane remains undamaged and retains its flatness. Our approach was optimized for MEMS-based heating chips but can be applied to any chip design. We show two different applications of this technique for (1) fabrication of a nanogap electrode by means of electromigration in thin free-standing metal films and (2) making low-noise graphene nanopore devices.
Homogenizing microwave illumination in thermoacoustic tomography by a linear-to-circular polarizer based on frequency selective surfaces
Authors: He Yu , Shen Yuecheng , Feng Xiaohua , Liu Changjun , Wang Lihong V.
Published: August 2017

A circularly polarized antenna, providing more homogeneous illumination compared to a linearly polarized antenna, is more suitable for microwave induced thermoacoustic tomography (TAT). The conventional realization of a circular polarization is by using a helical antenna, but it suffers from low efficiency, low power capacity, and limited aperture in TAT systems. Here, we report an implementation of a circularly polarized illumination method in TAT by inserting a single-layer linear-to-circular polarizer based on frequency selective surfaces between a pyramidal horn antenna and an imaging object. The performance of the proposed method was validated by both simulations and experimental imaging of a breast tumor phantom. The results showed that a circular polarization was achieved, and the resultant thermoacoustic signal-to-noise was twice greater than that in the helical antenna case. The proposed method is more desirable in a waveguide-based TAT system than the conventional method.
Thermal properties of graphene from path-integral simulations
Authors: Herrero Carlos P. , Ramírez Rafael
Published: August 2017

Thermal properties of graphene monolayers are studied by path-integral molecular dynamics simulations, which take into account the quantization of vibrational modes in the crystalline membrane and allow one to consider anharmonic effects in these properties. This system was studied at temperatures in the range from 12 to 2000 K and zero external stress, by describing the interatomic interactions through the LCBOPII effective potential. We analyze the internal energy and specific heat and compare the results derived from the simulations with those yielded by a harmonic approximation for the vibrational modes. This approximation turns out to be rather precise up to temperatures of about 400 K. At higher temperatures, we observe an influence of the elastic energy due to the thermal expansion of the graphene sheet. Zero-point and thermal effects on the in-plane and “real” surface of graphene are discussed. The thermal expansion coefficient α of the real area is found to be positive at all temperatures, in contrast to the expansion coefficient αp of the in-plane area, which is negative at low temperatures and becomes positive for T ≳ 1000 K.
Spin-dependent charge recombination along para-phenylene molecular wires
Authors: Fay Thomas P. , Lewis Alan M. , Manolopoulos David E.
Published: August 2017

We have used an efficient new quantum mechanical method for radical pair recombination reactions to study the spin-dependent charge recombination along PTZ•+–Phn–PDI•– molecular wires. By comparing our results with the experimental data of Weiss et al. [J. Am. Chem. Soc. 126, 5577 (2004)], we are able to extract the spin-dependent (singlet and triplet) charge recombination rate constants for wires with n = 2–5. These spin-dependent rate constants have not been extracted previously from the experimental data because they require fitting its magnetic field-dependence to the results of quantum spin dynamics simulations. We find that the triplet recombination rate constant decreases exponentially with the length of the wire, consistent with the superexchange mechanism of charge recombination. However, the singlet recombination rate constant is nearly independent of the length of the wire, suggesting that the singlet pathway is dominated by an incoherent hopping mechanism. A simple qualitative explanation for the different behaviours of the two spin-selective charge recombination pathways is provided in terms of Marcus theory. We also find evidence for a magnetic field-independent background contribution to the triplet yield of the charge recombination reaction and suggest several possible explanations for it. Since none of these explanations is especially compelling given the available experimental evidence, and since the result appears to apply more generally to other molecular wires, we hope that this aspect of our study will stimulate further experimental work.
Lie group classification of the nonlinear generalized Kompaneets equations with two functional parameters
Authors: Kovalenko S. , Patsiuk O.
Published: August 2017

We study the nonlinear generalized Kompaneets equations (GKEs) with two functional parameters. By using the Lie–Ovsiannikov algorithm, we carried out the group classification of the equations. It is shown that the kernel algebra of the full groups of the GKEs is the one-dimensional Lie algebra. We obtained nine non-equivalent (up to transformations from the equivalence group) nonlinear GKEs that allow wider invariance algebras than the kernel one. We found a number of exact solutions of those GKEs, which have the maximal symmetry properties.
A reflective-type, quasi-optical metasurface filter
Authors: Sima Boyu , Momeni Hasan Abadi Seyed Mohamad Amin , Behdad Nader
Published: August 2017

We introduce a new technique for designing quasi-optical, reflective-type spatial filters. The proposed filter is a reflective metasurface with a one dimensional, frequency-dependent phase gradient along the aperture. By careful design of each unit cell of the metasurface, the phase shift gradient provided by the adjacent unit cells can be engineered to steer the beam towards a desired, anomalous reflection direction over the passband region of the filter. Outside of that range, the phase shift gradient required to produce the anomalous reflection is not present and hence, the wave is reflected towards the specular reflection direction. This way, the metasurface acts as a reflective filter in a quasi-optical system where the detector is placed along the direction of anomalous reflection. The spectral selectivity of this filter is determined by the frequency dispersion of the metasurface's phase response. Based on this principle, a prototype of the proposed metasurface filter, which operates at 10 GHz and has a bandwidth of 3%, is designed. The device is modeled using a combination of theoretical analysis using the phased-array theory and full-wave electromagnetic simulations. A prototype of this device is also fabricated and characterized using a free-space measurement system. Experimental results agree well with the simulations.
Energy loss of terahertz electromagnetic waves by nano-sized connections in near-self-complementary metallic checkerboard patterns
Authors: Takano Keisuke , Tanaka Yoku , Moreno Gabriel , Chahadih Abdallah , Ghaddar Abbas , Han Xiang-Lei , Vaurette François , Nakata Yosuke , Miyamaru Fumiaki , Nakajima Makoto , Hangyo Masanori , Akalin Tahsin
Published: August 2017

The design of a self-complementary metallic checkerboard pattern achieves broadband, dispersion-less, and maximized absorption, concentrating in deep subwavelength resistive connections between squares, without any theoretical limitation on the energy absorbing area. Here, we experimentally and numerically investigate the electromagnetic response in the limit of extremely small connections. We show that finite conductivity and randomness in a near-self-complementary checkerboard pattern play a crucial role in producing a frequency-independent energy loss in the terahertz frequency region. Here, metals behave like an almost perfect conductor. When the checkerboard pattern approaches the perfect self-complementary pattern, the perfect conductor approximation spontaneously breaks down, owing to the finite conductivity at the nano-scale connection, leading to broadband absorption. It is also shown that the random connections between metallic squares also lead to broadband and maximized energy loss through scattering loss, similar to finite conductivity.
Effect of shell thickness on the exchange bias blocking temperature and coercivity in Co-CoO core-shell nanoparticles
Authors: Thomas S. , Reethu K. , Thanveer T. , Myint M. T. Z. , Al-Harthi S. H.
Published: August 2017

The exchange bias blocking temperature distribution of naturally oxidized Co-CoO core-shell nanoparticles exhibits two distinct signatures. These are associated with the existence of two magnetic entities which are responsible for the temperature dependence of an exchange bias field. One is from the CoO grains which undergo thermally activated magnetization reversal. The other is from the disordered spins at the Co-CoO interface which exhibits spin-glass-like behavior. We investigated the oxide shell thickness dependence of the exchange bias effect. For particles with a 3 nm thick CoO shell, the predominant contribution to the temperature dependence of exchange bias is the interfacial spin-glass layer. On increasing the shell thickness to 4 nm, the contribution from the spin-glass layer decreases, while upholding the antiferromagnetic grain contribution. For samples with a 4 nm CoO shell, the exchange bias training was minimal. On the other hand, 3 nm samples exhibited both the training effect and a peak in coercivity at an intermediate set temperature Ta. This is explained using a magnetic core-shell model including disordered spins at the interface.
Maternal Group B Streptococcus colonisation
Authors: Furfaro Lucy , Chang Barbara , Payne Matthew
Published: August 2017

Streptococcus agalactiae, commonly known as Group B Streptococcus (GBS), is an important neonatal pathogen known to cause sepsis, meningitis and pneumonia. Australian pregnant women undergo screening during pregnancy in an effort to eradicate GBS before delivery where transmission to the neonate can occur. Preventative treatment includes intrapartum antibiotic prophylaxis and results in widespread treatment of the 10–40% of pregnant women colonised. GBS are separated into ten different capsular polysaccharide serotypes and previous studies have suggested associations between specific serotypes and disease. At present, however, minimal data exist on serotype distribution within Western Australian-pregnant women, information that may play an important role in future prophylactic treatment regimens. Our preliminary data, obtained from GBS isolated from vaginal swabs from 191 pregnant women, suggests that GBS serotype distributions in Western Australia are different to other parts of Australasia. In particular, compared to the eastern Australian states and New Zealand, in our cohort, serotype Ib prevalence was 7–17 times lower, II was 2–6 times greater and VI was 2–12 times greater. In addition, serotype IX represented 6.3% of all serotypes. Understanding which serotypes are present in our population will provide valuable data for future targeted treatment regimens such as vaccination and bacteriophage therapy.
MicroRNA-mediated disruption of dendritogenesis during a critical period of development influences cognitive capacity later in life
Authors: Lin Quan , Ponnusamy Ravikumar , Widagdo Jocelyn , Choi Jung A. , Ge Weihong , Probst Christine , Buckley Tyler , Lou Mimi , Bredy Timothy W. , Fanselow Michael S. , Ye Keqiang , Sun Yi E.
Published: August 2017

Significance

This study expands our knowledge of small noncoding RNAs and their important roles in brain development and cognitive function. We describe a mechanism by which dendritic morphology and synaptic formation are altered during a critical period of development, eventually leading to altered capacity for learning and memory later in life.
Local-Scale Spectroscopic Studies of Vortex Organization in Mesoscopic Superconductors
Authors: Roditchev D. , Cren T. , Brun C. , Milošević M.V.
Published: August 2017

This article examines the vortex matter of mesoscopic superconductors with numerous vortex states that do not exist in bulk superconductors. Using scanning tunneling microscopy/spectroscopy, it investigates the organization of vortex cores at different levels of confinement. The article begins with a discussion of the basic properties of quantum vortices in superconductors and experimental requirements for studying vortex confinement phenomena. It then considers the effect of sample size and shape on vortex distribution and pinning, along with the resulting ultra-dense configurations that cannot be achieved in bulk superconductors. It also describes the peculiar features of vortices in atomically thin superconductors having mixed Abrikosov–Josephson vortices.
Andreev Reflection and Related Studies in Low-Dimensional Superconducting Systems
Authors: Daghero D. , Ummarino G.A. , Gonnelli R.S.
Published: August 2017

This article investigates the potential of the point contact Andreev reflection spectroscopy (PCARS) technique for measuring the symmetry of the energy gap and other key parameters of various 0-, 1-, and 2-dimensional superconducting systems. It begins with a brief description of PCARS, explaining what a point contact is and how it can be made and the conditions under which a PC is ballistic, as well as why and to what extent a PC between normal metals is spectroscopic. It then discusses the basics of Andreev reflection and the length scales in mesoscopic systems before considering the limits of applicability of PCARS for spectroscopy of ‘small’ superconductors. Finally, it reviews some examples of PCARS in quasi-0D, quasi-1D and quasi-2D superconductors.
Topological Superconductors and Majorana Fermions
Authors: Li Y.Y. , Jia J.F.
Published: August 2017

This article discusses recent developments relating to the so-called topological superconductors (TSCs), which have a full pairing gap in the bulk and gapless surface states consisting of Majorana fermions (MFs). It first provides a background on topological superconductivity as a novel quantum state of matter before turning to topological insulators (TIs) and superconducting heterostructures, with particular emphasis on the vortices of such materials and the Majorana mode within a vortex. It also considers proposals for realizing TSCs by proximity effects through TI/SC heterostructures as well as experimental efforts to fabricate artificial TSCs using nanowires, superconducting junctions, and ferromagnetic atomic chains on superconductors.
Theoretical Study of THz Emission from HTS Cuprate
Authors: Asai H.
Published: August 2017

This article examines the THz emission from high-temperature superconducting (HTS) cuprates in the mesoscopic state using the intrinsic Josephson junction model. Cuprate superconductors are high-temperature superconductors that exhibit exotic electromagnetic properties. One of the remarkable features of HTS cuprates is high anisotropy due to their layered structures. Almost all HTS cuprates are composed of stacks of CuO2 layers and blocking layers which supply charge carriers to the CuO2 layers. The crystal structures of the HTS cuprates naturally form Josephson junctions known as intrinsic Josephson junctions (IJJs). This article first describes the basic theory of IJJ and the mechanism of THz emission before discussing the effect of temperature inhomogeneity on the emission properties. It then introduces a novel IJJ-based THz emitter that utilizes laser heating. Theoretical results show that the THz emission is caused by the strong excitation of transverse Josephson plasma waves in IJJs under a direct current bias.
Leibnizian analysis, canonical objects, and generalization
Authors: Grosholz Emily
Published: August 2017

This article examines Gottfried Leibniz’s notion of analysis by focusing on his investigation of transcendental curves. It argues that Leibnizian analysis can be understood as an art of both discovery and justification in mathematics that aims for generalization rather than abstraction, and explanation rather than formal proof. The article first considers Leibniz’s work on the catenary before discussing some of his pronouncements on analysis as the search for conditions of intelligibility. It also evaluates some modern accounts of Leibniz’s notion of analysis by contemporary philosophers, including Carlo Cellucci, Herbert Breger, and Nancy Cartwright. It argues that concrete terms can be used to say something true only when they are combined with more abstract locutions that express the conditions of intelligibility of the thing denoted, the formal causes that make the thing what it is and so make its resemblance to other things possible.
Biological generality
Authors: Barbara Jean- Gaël
Published: August 2017

This article examines generality in biology by focusing on two French schools of anatomy: the discipline of anatomie générale that was founded in France in 1800 by Xavier Bichat and the one developed in the 1870s by Louis Ranvier at the Collège de France by means of microscopy. The works of Bichat and Ranvier involved the disciplines of anatomy and physiology. Bichat’s work, especially his research on tissues, is of interest for understanding which kind of concept of generality gained favor in the life sciences at the start of the nineteenth century. Ranvier’s later career sheds light on the ways that generality was searched for at the microscopic level and its significance in the discovery of real and minute biological objects. Following a discussion of Bichat and Ranvier’s anatomie générale, this article explores the two men’s interests in generality as an actor’s category.
Questions of generality as probes into nineteenth-century mathematical analysis
Authors: Chorlay Renaud
Published: August 2017

This article examines ways of expressing generality and epistemic configurations in which generality issues became intertwined with epistemological topics, such as rigor, or mathematical topics, such as point-set theory. In this regard, three very specific configurations are discussed: the first evolving from Niels Henrik Abel to Karl Weierstrass, the second in Joseph-Louis Lagrange’s treatises on analytic functions, and the third in Emile Borel. Using questions of generality, the article first compares two major treatises on function theory, one by Lagrange and one by Augustin Louis Cauchy. It then explores how some mathematicians adopted the sophisticated point-set theoretic tools provided for by the advocates of rigor to show that, in some way, Lagrange and Cauchy had been right all along. It also introduces the concept of embedded generality for capturing an approach to generality issues that is specific to mathematics.
Universality versus generality
Authors: Barbin Evelyne
Published: August 2017

This article examines the ‘dispute over tangents’ between René Descartes and Pierre de Fermat, which began in 1638, by comparing their methods of constructing tangents. Descartes’s method aims at a universality, whereas Fermat’s method aims at a generality. The article begins with a discussion of Descartes’s method of tangents, which he proposed in 1637 as a way of constructing ‘all the problems of geometry’. It then considers Fermat’s method, in which he introduces a rule for finding a maximum or minimum. It also looks at Descartes’s critiques of Fermat’s method as applied to the ellipse and the hyperbola, and how Fermat arrived at the question of the ‘specific property’ of a curve by constructing the tangents to non-geometric curves.
Generality, generalization, and induction in Poincaré’s philosophy
Authors: Ly Igor
Published: August 2017

This article examines Henri Poincaré’s philosophical conceptions of generality in mathematics and physics, and more specifically his claim that induction in experimental physics does not consist in extending the domain of a predicate. It first considers Poincaré’s view that generalization is not a means to reach generality and that the issue of infinity is related to the theme of generality. It then shows how generality in mathematics and physics is construed by Poincaré in a very specific way and how he analyzes empirical induction in physics. It also analyzes the distinction suggested by Poincaré between generalizations used in mathematical physics and generalizations used by ‘naturalists’. In particular, it explains the distinction between mathematical generality and the so-called predicative generality. Finally, it compares Poincaré’s concern regarding empirical induction with Nelson Goodman’s ‘new riddle of induction’, arguing that ‘the new riddle of induction’ was originally formulated by Poincaré half a century earlier.
Nanoelectronic devices: A unified view
Authors: Datta Supriyo
Published: August 2017

This article describes the conceptual framework that provides a unified description for all kinds of nanoelectronic devices covering different transport regimes from the diffusive to the ballistic limit, including molecular conductors, carbon nanotubes, and silicon transistors. More specifically, it presents a unified bottom-up viewpoint to the subject of electrical conduction of particular relevance to nanoelectronic devices and highlights the important role played by contacts. It also discusses the basic inputs that define the NEGF–Landauer model, along with its relevant equations, including those that provide a general approach to the problem of quantum transport. A few examples are given to illustrate how these equations are applied.
Reaction studies on nanostructured surfaces
Authors: Winkler Adolf
Published: August 2017

This article examines the properties of some self-organized nanostructured surfaces with respect to specific model reactions, from a surface-science point of view. It begins with an overview of the most important types of nanostructured surfaces, their preparation and characterization. It then considers the fundamentals of reaction processes, focusing on the kinetics and dynamics of adsorption and desorption. It also describes the experimental techniques used in the context of reaction studies under ultrahigh-vacuum conditions. Finally, it presents some experimental results of model reactions, including hydrogen adsorption and desorption on stepped nickel surfaces, methanol adsorption on self-assembled copper-copper oxide surfaces, and hydrogen desorption and water formation on vanadium-oxide nanostructures on palladium surfaces.
Nanotribology
Authors: Biswas S.K.
Published: August 2017

This article provides an overview of nanotribology, with particular emphasis on the scalable regime where contact dimensions, topographical perturbations, confinement scale and molecular dimensions are of the same order. It first defines nanotribology and describes some of the instruments used to assess the physics and chemistry of materials in the contact region, including the atomic force microscope, surface force apparatus, and quartz crystal microbalance. It then considers the interfacial phenomena and interaction forces as well as the microscopic origins of friction, focusing on Amonton's Law at the single asperity, atomistic modelling of adhesion and friction, and analysis of coherence in molecular lubrication by means of the Eyring equation. The article also examines the problem of boundary lubrication in two cases: oil in confinement and self-assembled additives in confinement.
Quantum-theoretical approaches to proteins and nucleic acids
Authors: Boero Mauro , Tateno Masaru
Published: August 2017

This article describes quantum methods used to study proteins and nucleic acids: Hartree–Fock all-electron approaches, density-functional theory approaches, and hybrid quantum-mechanics/molecular-mechanics approaches. In addition to an analysis of the electronic structure, quantum-mechanical approaches for simulating proteins and nucleic acids can elucidate the cleavage and formation of chemical bonds in biochemical reactions. This presents a computational challenge, and a number of methods have been proposed to overcome this difficulty, including enhanced temperature methods such as high-temperature molecular dynamics, parallel tempering and replica exchange. Alternative methods not relying on the knowledge a priori of the final products make use of biasing potentials to push the initial system away from its local minimum and to enhance the sampling of the free-energy landscape. This article considers two of these biasing techniques, namely Blue Moon and metadynamics.
Novel superconducting states in nanoscale superconductors
Authors: Kanda A. , Ootuka Y. , Kadowaki K. , Peeters F.M.
Published: August 2017

This article describes novel superconducting states in nanoscale superconductors. It first considers characteristic lengths in superconductors and vortices in mesoscopic superconductors before discussing trends in superconductivity research, which is closely related to recent progress in nanotechnology. It then explains the theoretical methods used for the study of mesoscopic superconducting states, along with theoretical predictions of vortex states in thin mesoscopic superconducting films. It also looks at experimental techniques used for the detection of vortices, including direct visualization of the vortex positions and indirect methods such as the multiple-small-tunnel-junction method, and experimental detection of mesoscopic vortex states in disks and squares. Finally, it evaluates one-dimensional vortex in mesoscopic rings.
Correlated electron transport in molecular junctions
Authors: Thygesen K.S. , Rubio A.
Published: August 2017

This article focuses on correlated electron transport in molecular junctions. More specifically, it considers how electronic correlation effects can be included in transport calculations using many-body perturbation theory within the Keldysh non-equilibrium Green’s function formalism. The article uses the GW self-energy method (G denotes the Green’s function and W is the screened interaction) which has been successfully applied to describe quasi-particle excitations in periodic solids. It begins by formulating the quantum-transport problem and introducing the non-equilibrium Green’s function formalism. It then derives an expression for the current within the NEGF formalism that holds for interactions in the central region. It also combines the GW scheme with a Wannier function basis set to study electron transport through two prototypical junctions: a benzene molecule coupled to featureless leads and a hydrogen molecule between two semi-infinite platinum chains. The results are analyzed using a generic two-level model of a molecular junction.
NEGF-based models for dephasing in quantum transport
Authors: Golizadeh-Mojarad Roksana , Datta Supriyo
Published: August 2017

This article describes the use of NEGF-based models for elastic dephasing in quantum transport. The non-equilibrium Green's function (NEGF) method provides a rigorous prescription for including any kind of dephasing mechanisms to any order starting from a microscopic Hamiltonian through an appropriate choice of the self-energy function. The article first introduces the general approach to quantum transport that provides a general method for modelling a wide class of nanotransistor and spin devices. It then discusses the effect of different types of dephasing on momentum and spin relaxation before considering three simple phenomenological choices of the self-energy function that allows one to incorporate spin, phase and momentum relaxation independently. It also looks at an example that takes into account these three types of dephasing mechanisms: the ‘spin-Hall’ effect.