bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescent protein-based detection of unconjugated bilirubin in newborn serum
Authors: Iwatani Sota , Nakamura Hajime , Kurokawa Daisuke , Yamana Keiji , Nishida Kosuke , Fukushima Sachiyo , Koda Tsubasa , Nishimura Noriyuki , Nishio Hisahide , Iijima Kazumoto , Miyawaki Atsushi , Morioka Ichiro
Published: June 2016

Increased serum levels of unconjugated bilirubin are associated with the development of brain damage in newborns. In current clinical settings, there are no methods for directly determining serum levels of unconjugated bilirubin. UnaG, a fluorescent protein from Japanese eel muscle that specifically binds to unconjugated bilirubin was used in this study. Linear regression analysis was carried out to compare unconjugated bilirubin levels measured by UnaG and conventional bilirubin oxidase methods. Unconjugated bilirubin levels in the serum of newborns who were untreated or treated with phototherapy were compared. Effects of interfering factors in the serum (conjugated bilirubin, hemoglobin and lipid) on unconjugated bilirubin concentration measured by the UnaG method were also evaluated. Unconjugated bilirubin levels measured by the UnaG method were highly correlated with those determined by the bilirubin oxidase assay. Unconjugated bilirubin levels determined by bilirubin oxidase and UnaG assays were similar in serum samples containing conjugated bilirubin. The performance of the UnaG assay was unaffected by phototherapy and the presence of serum hemoglobin and lipid emulsion. These results demonstrate the clinical applicability of the UnaG method for direct measurement of unconjugated bilirubin levels in newborn serum.
Allosteric modulation of AURKA kinase activity by a small-molecule inhibitor of its protein-protein interaction with TPX2
Authors: Janeček Matej , Rossmann Maxim , Sharma Pooja , Emery Amy , Huggins David J. , Stockwell Simon R. , Stokes Jamie E. , Tan Yaw S. , Almeida Estrella Guarino , Hardwick Bryn , Narvaez Ana J. , Hyvönen Marko , Spring David R. , McKenzie Grahame J. , Venkitaraman Ashok R.
Published: June 2016

The essential mitotic kinase Aurora A (AURKA) is controlled during cell cycle progression via two distinct mechanisms. Following activation loop autophosphorylation early in mitosis when it localizes to centrosomes, AURKA is allosterically activated on the mitotic spindle via binding to the microtubule-associated protein, TPX2. Here, we report the discovery of AurkinA, a novel chemical inhibitor of the AURKA-TPX2 interaction, which acts via an unexpected structural mechanism to inhibit AURKA activity and mitotic localization. In crystal structures, AurkinA binds to a hydrophobic pocket (the ‘Y pocket’) that normally accommodates a conserved Tyr-Ser-Tyr motif from TPX2, blocking the AURKA-TPX2 interaction. AurkinA binding to the Y- pocket induces structural changes in AURKA that inhibit catalytic activity in vitro and in cells, without affecting ATP binding to the active site, defining a novel mechanism of allosteric inhibition. Consistent with this mechanism, cells exposed to AurkinA mislocalise AURKA from mitotic spindle microtubules. Thus, our findings provide fresh insight into the catalytic mechanism of AURKA and identify a key structural feature as the target for a new class of dual-mode AURKA inhibitors, with implications for the chemical biology and selective therapeutic targeting of structurally related kinases.
Probing the Origin of Challenge of Realizing Metallaphosphabenzenes: Unfavorable 1,2-Migration in Metallapyridines Becomes Feasible in Metallaphosphabenzenes
Authors: Wu Jingjing , Hao Yulei , Zhu Jun
Published: June 2016

Metallabenzenes have attracted considerable interest of both theoretical and experimental chemists. However, metallaphosphabenzene has never been synthesized. Thus, understanding the origin of the challenge of synthesizing metallaphosphabenzene is particularly urgent for experimentalists. Now density functional theory (DFT) calculations have been carried out to examine this issue. Our results reveal that the 1,2-migration in metallapyridines is unfavorable whereas such a 1,2-migration in metallaphosphabenzenes is feasible, which can be rationalized by the reluctance of phosphorus to participate in π bonding. In addition, π-donor ligands and the 5d transition metals can stabilize metallaphosphabenzenes. Compared with hydride and methyl migration, the chloride migration has a relatively lower activation barrier due to the polarization of the M=P bond. CO ligand could further decrease the reaction barrier of the migration due to the reduction of the interaction between the metal centre and the phosphorus atom. All of these findings could help synthetic chemists to realize the first metallaphosphabenzene.
Sperm whale predator-prey interactions involve chasing and buzzing, but no acoustic stunning
Authors: Fais A. , Johnson M. , Wilson M. , Aguilar Soto N. , Madsen P. T.
Published: June 2016

The sperm whale carries a hypertrophied nose that generates powerful clicks for long-range echolocation. However, it remains a conundrum how this bizarrely shaped apex predator catches its prey. Several hypotheses have been advanced to propose both active and passive means to acquire prey, including acoustic debilitation of prey with very powerful clicks. Here we test these hypotheses by using sound and movement recording tags in a fine-scale study of buzz sequences to relate the acoustic behaviour of sperm whales with changes in acceleration in their head region during prey capture attempts. We show that in the terminal buzz phase, sperm whales reduce inter-click intervals and estimated source levels by 1–2 orders of magnitude. As a result, received levels at the prey are more than an order of magnitude below levels required for debilitation, precluding acoustic stunning to facilitate prey capture. Rather, buzzing involves high-frequency, low amplitude clicks well suited to provide high-resolution biosonar updates during the last stages of capture. The high temporal resolution helps to guide motor patterns during occasionally prolonged chases in which prey are eventually subdued with the aid of fast jaw movements and/or buccal suction as indicated by acceleration transients (jerks) near the end of buzzes.
iTRAQ-Based Proteomics Screen identifies LIPOCALIN-2 (LCN-2) as a potential biomarker for colonic lateral-spreading tumors
Authors: Wang Xianfei , Li Aimin , Guo Yubin , Wang Yadong , Zhao Xinhua , Xiang Li , Han Zelong , Li Yue , Xu Wen , Zhuang Kangmin , Yan Qun , Zhong Jietao , Xiong Jing , Liu Side
Published: June 2016

The improvement and implementation of a colonoscopy technique has led to increased detection of laterally spreading tumors (LSTs), which are presumed to constitute an aggressive type of colonic neoplasm. Early diagnosis and treatment of LSTs is clinically challenging. To overcome this problem, we employed iTRAQ to identify LST-specific protein biomarkers potentially involved in LST progression. In this study, we identified 2,001 differentially expressed proteins in LSTs using iTRAQ-based proteomics technology. Lipocalin-2 (LCN-2) was the most up-regulated protein. LSTs expression levels of LCN-2 and matrix metallopeptidase-9 (MMP-9) showed positive correlation with worse pathological grading and up-regulation of these proteins in LSTs was also reflected in serum. Furthermore, LCN-2 protein overexpression was positively correlated with MMP-9 protein up-regulation in the tumor tissue and serum of LST patients (former rs = 0.631, P = 0.000; latter rs = 0.815, P = 0.000). Our results suggest that LCN-2 constitutes a potential biomarker for LST disease progression and might be a novel therapeutic target in LSTs.
Photochemical Isomerization and Topochemical Polymerization of the Programmed Asymmetric Amphiphiles
Authors: Kim Dae-Yoon , Lee Sang-A , Jung Daseal , Jeong Kwang-Un
Published: June 2016

For the advancement in multi-stimuli responsive optical devices, we report the elaborate molecular engineering of the dual photo-functionalized amphiphile (abbreviated as AZ1DA) containing both a photo-isomerizable azobenzene and a photo-polymerizable diacetylene. To achieve the efficient photochemical reactions in thin solid films, the self-assembly of AZ1DA molecules into the ordered phases should be precisely controlled and efficiently utilized. First, the remote-controllable light shutter is successfully demonstrated based on the reversible trans-cis photo-isomerization of azobenzene group in the smectic A mesophase. Second, the self-organized monoclinic crystal phase allows us to validate the photo-polymerization of diacetylene moiety for the photo-patterned thin films and the thermo-responsible color switches. From the demonstrations of optically tunable thin films, it is realized that the construction of strong relationships between chemical structures, molecular packing structures and physical properties of the programmed molecules is the core research for the development of smart and multifunctional soft materials.
Mesoporous Nano-Silica Serves as the Degradation Inhibitor in Polymer Dielectrics
Authors: Yang Yang , Hu Jun , He Jinliang
Published: June 2016

A new generation of nano-additives for robust high performance nanodielectrics is proposed. It is demonstrated for the first time that mesoporous material could act as “degradation inhibitor” for polymer dielectrics to sequestrate the electrical degradation products then restrain the electrical aging process especially under high temperature conditions, which is superior to the existing additives of nanodielectrics except further increasing the dielectric strength. Polyethylenimine (PEI) loaded nano-scaled mesoporous silica MCM-41 (nano-MS) is doped into the dielectric matrix to prepare the PP/MCM-41-PEI nanocomposites. PEI provides the amines to capture the electrical degradation products while the MCM-41 brackets afford large adsorption surface, bring down the activating temperature of the absorbent then enhance the absorptive capacity. The electrical aging tests confirm the contribution of the mesoporous structure to electrical aging resistance and FT-IR analysis of the electrical degraded regions demonstrates the chemical absorption especially under high temperature conditions. Take the experimental data as examples, extending the aging durability and dielectric strength of polymer dielectrics by 5 times and 16%, respectively, can have substantial commercial significance in energy storage, power electronics and power transmission areas.
Synthesis and structural evolution of dual-boron-source-modified polysilazane derived SiBCN ceramics
Authors: Zhang Qian , Yang Zhihua , Jia Dechang , Chen Qingqing , Zhou Yu
Published: June 2016

A dual-boron-source approach is proposed to enrich the boron content of SiBCN ceramics through aminolysis and hydroboration reactions.
Fully reversible three-state interconversion of metallosupramolecular architectures
Authors: Mittal Nikita , Saha Manik Lal , Schmittel Michael
Published: June 2016

The reversible switching of a sterically encumbered phenanthroline–Cu+–picolinaldehyde trio back and forth between homoleptic and heteroleptic coordination using the relative metal-ion to ligand ratio is the basis for an unprecedented cyclic three-state interconversion of metallacycles.
Anderson-like alkoxo-polyoxovanadate clusters serving as unprecedented second building units to construct metal–organic polyhedra
Authors: Zhang Yu-Teng , Wang Xin-Long , Li Shuang-Bao , Gong Ya-Ru , Song Bai-Qiao , Shao Kui-Zhan , Su Zhong-Min
Published: June 2016

A series of vanadium-based metal–organic polyhedra were obtained through the self-assembly of Anderson-like alkoxo-polyoxovnadate {V6S} clusters with different carboxylate ligands.
A guide to the selection of switchable functional groups for CO2-switchable compounds
Authors: Alshamrani A. K. , Vanderveen J. R. , Jessop P. G.
Published: June 2016

CO2-responsive species in water interconvert between neutral and bicarbonate forms, but only if the species has appropriate basicity.
Planar B3S2H3−and B3S2H3clusters with a five-membered B3S2ring: boron–sulfur hydride analogues of cyclopentadiene
Authors: Li Da-Zhi , Li Rui , Zhang Li-Juan , Ou Ting , Zhai Hua-Jin
Published: June 2016

Boron–sulfur hydride clusters,C2vB3S2H3−and B3S2H3, possess a five-membered B3S2ring as the core, which is analogous to cyclopentadiene in terms of π bonding.
Introduction to the Nitrogen Ligands Themed Issue
Authors: Denat Franck , Gros Claude P.
Published: June 2016

From the 6th EuCheMS Conference on Nitrogen Ligands (Beaune 2015) to an NJC themed issue.
Cationic palladium(ii)-catalyzed dehydrative nucleophilic substitutions of benzhydryl alcohols with electron-deficient benzenethiols in water
Authors: Hikawa Hidemasa , Machino Yumo , Toyomoto Mariko , Kikkawa Shoko , Azumaya Isao
Published: June 2016

An efficient direct nucleophilic substitution of benzhydryl alcohols with electron-deficient benzenethiols using cationic Pd(ii) catalysts as Lewis acids in water is reported.
Cationic ring-opening polymerization of protected oxazolidine imines resulting in gradient copolymers of poly(2-oxazoline) and poly(urea)
Authors: Leiske Meike N. , Hartlieb Matthias , Sobotta Fabian H. , Paulus Renzo M. , Görls Helmar , Bellstedt Peter , Schubert Ulrich S.
Published: June 2016

Synthesis of well-defined poly(urea)-poly(2-ethyl-2-oxazoline) gradient copolymers.
Highly selective separation of individual platinum group metals (Pd, Pt, Rh) from acidic chloride media using phosphonium-based ionic liquid in aromatic diluent
Authors: Nguyen Viet Tu , Lee Jae-chun , Chagnes Alexandre , Kim Min-seuk , Jeong Jinki , Cote Gérard
Published: June 2016

An effective solvent extraction-based method has been developed to recover individually platinum group metals (Pd, Pt, and Rh) with high purity from acidic chloride media using phosphonium-based ionic liquid Cyphos IL 101 in aromatic solvent.
Facile and green preparation of biobased graphene oxide/furan resin nanocomposites with enhanced thermal and mechanical properties
Authors: Li Chen , Li Shengfang , Yan Shilin
Published: June 2016

A facile and green approach was developed to prepare biobased graphene oxide (GO)/furan resin nanocomposites by directly transferring GO from water dispersion into furan resin.
Evaluation of two W‐band power dividers in a subwavelength dielectric fibre technology
Authors: Reese R. , Jost M. , Jakoby R.
Published: June 2016

The design and characterisation of two different power divider techniques, i.e. Y‐branch and multimodal power dividers, based on subwavelength dielectric fibre technology is presented. Both have been successfully established in the optical domain for dielectric waveguides and are adapted to W‐band frequencies (75–110 GHz). Both power dividers are made out of the cross‐linked polystyrene Rexolite 1422 and have been processed by milling. Simulations predicted insertion losses between 3.5 and 4 dB while the electrical characterisation showed insertion losses between 3.5 and 5 dB. The multimodal power divider has the best performance with 1–1.5 dB lower insertion losses compared with the Y‐branch divider.
Outage capacity and source distortion analysis for NOMA users in 5G systems
Authors: Islam S.M.R. , Kwak K.S.
Published: June 2016

This Letter analyses the impact of the outage probability on the outage capacity and the expected source distortion of information transmission to non‐orthogonal multiple access (NOMA) users with a fixed set of power allocation coefficients. The analysis shows that the outage probability at which a strong user experiences the maximum outage capacity (and the minimum expected distortion) is characteristically different from that of a weak user. Moreover, the outage probability that maximises the outage capacity does not provide the minimum source distortion for both users. The analysis is validated against simulation.
Efficient CIC‐based architecture with improved aliasing rejection and reduced computational complexity
Authors: Romero D.E.T.
Published: June 2016

A useful cascaded integrator comb (CIC)‐based architecture is presented that improves the worst‐case alias rejection of the CIC filter and simultaneously reduces the computational load of its integration section. Since regularity and simplicity are acceptably preserved, the proposed design outperforms other recent CIC‐based architectures from literature where these two desirable characteristics are severely affected.
Tag diversity of inkjet printed body‐worn radio frequency identification integrated medical sticking plasters for wireless monitoring
Authors: Oyeka Dumtoochukwu O. , Batchelor John C. , Ziai Ali M. , Wheeler Joseph , Yeates Stephen
Published: June 2016

This Letter presents an investigation of radio frequency identification tags integrated with sticking plasters. Conductive ink is used in the fabrication to provide good compatibility with the plaster in terms of flexibility. The tag is proposed for use as a wireless platform for long‐term patient monitoring in hospital environments. A motion capture system is used to test the directions in which the tag can be read to inform a diversity study establishing the number of tags required on‐body to ensure reliable reading for applications such as medical monitoring. Tag diversity performance with various body movements is also studied. It is established that four tags give all round body coverage with only 4% loss in coverage for vertically polarised tags should one of them fail.
Single channel steepest descent algorithm for the correction of cycle frequency error
Authors: Cai Xin , Wang Xiang , Huang Zhi‐Tao , Wang Feng‐Hua
Published: June 2016

The beneficial characteristics of signal cyclostationarity have been widely exploited in varied domains. However, one common problem is that algorithms adopting cyclostationarity would suffer from severe performance degradation when there is an error or mismatch in the cycle frequency (CF) involved. Hence, the authors attempt to propose a single channel correction method for CF error (CFE). First, a new cyclostationary spectral feature function is introduced which reaches its maxima at CFs; second, the steepest descent algorithm is deduced for the correction of CFE, the convergence property of which is also discussed. The main contributions of the novel scheme are that first, the estimation accuracy is remarkably improved compared with most existing algorithms adopting cyclic feature functions. Second, the steepest descent scheme holds an advantage in computational complexity compared with previous works based on linear search. Moreover, the proposed algorithm is robust against the pulse shape variation and multipath fading. Simulation works are carried out, which demonstrate the performance of the algorithm under varied environment conditions, and results fit well with theoretical analysis. Comparisons with existing methods are also presented, together with examples to illustrate how the correction scheme can be applied in real systems.
Sensitive incipient inter‐turn fault detection algorithm for power transformers
Authors: Venikar Prasad A. , Ballal Makarand S. , Umre Bhimrao S. , Suryawanshi Hiralal M.
Published: June 2016

This study presents a sensitive and online approach for transformer inter‐turn fault detection at the inception stage. The technique is based on computation and application of difference in positive sequence impedance and difference in negative sequence current of transformer. A new characteristic plot is developed for this purpose from the transformer nameplate details and test results. The settings of the proposed algorithm adapt online for on‐load tap changer operation. The proposed technique is verified through simulation, and results are experimentally validated on a specially designed 10 kVA transformer. The results suggest significant improvement in sensitivity for inter‐turn fault detection as compared with commercially available dual slope differential protection scheme.
Enhanced evolutionary heuristic approaches for remote metering smart grid networks
Authors: Miao Hui , Chen Guo , Dong Zhaoyang
Published: June 2016

For a smart grid network, the communication infrastructure is an important part to provide the stability and reliability. To build an efficient communication network is crucial for the success of a smart grid network. This study improves the previous published work by proposing two novel evolutionary heuristic approaches (discrete differential evolutionary clustering approach and particle swarm optimisation clustering approach) to obtain the minimum number and location of the powerful nodes to fulfil the connectivity requirement of a smart meters network. The contribution of this study includes the designing and implementing of the two novel evolutionary heuristic approaches which could significantly improve the optimal solution [the least number of the local data centres (powerful nodes)] for a smart meter network which has arbitrary number of smart meters (ordinary nodes) with arbitrary transmission range. Comprehensive case studies and numerical statistical analysis demonstrate that the approaches could efficiently obtain better optimal results, and the connectivity of the smart meter network could be fulfilled with minimum number of the powerful nodes.
All‐optical 2's complement number conversion scheme without binary addition
Authors: Chattopadhyay Tanay , Gayen Dilip Kumar
Published: June 2016

In conventional method, 2's complement number conversion can be easily done by adding a binary bit ‘1’ with 1's complement of any binary number. In this study, the authors have proposed a new method where no addition is required. Also, an all‐optical n ‐bit conversion circuit has been proposed here. The authors have used logic sum and binary XOR operation to build their design. Optical logic sum circuit can be easily designed with an N  ×  1 beam combiner. Also, binary XOR operation has been designed with a Mach–Zehnder interferometer (MZI) having quantum dot semiconductor optical amplifier placed in each arm. The novelty of this circuit is that they required only one MZI to design it. To get the proper result and performance of the circuit, numerical simulations have been done.
Performance of artificial neural network in prediction of heave displacement for non‐buoyant type wave energy converter
Authors: Nagulan Santhosh , Selvaraj Jegadheeswaran , Arunachalam Amarkarthik , Sivanandam Kaushik
Published: June 2016

Non‐buoyant type of wave energy converter is an innovative method to harness ocean waves. In this paper the assessment of heave displacement for non‐buoyant type wave energy converter is investigated by means of artificial neural networks (ANNs). The significant water wave amplitude and time period are chosen as a basis for the heave displacement, and thus these two parameters are considered as effective parameters for the development of ANN model. For this purpose a wide range of dataset of about 4500 data (water wave amplitude and time period (seconds) is considered as input parameter and corresponding heave amplitude of non‐buoyant body is considered as output parameter) is obtained from an extensive laboratory campaign and is used to develop an ANN. The developed model has the capability of predicting the position of non‐buoyant five seconds ahead of actual heave displacement. The AI technique chosen for the model is a nonlinear autoregressive network with exogenous inputs (NARX) trained with the Levenberg‐Marquardt algorithm. A comparative study of 30 different architectures is carried out and finally the best performing ANN architecture is selected and successfully validated based on the measured data.
Average relay transmit‐power analysis in dual‐hop amplify‐and‐forward relaying systems
Authors: Zhao Haifeng , Pan Zhibin
Published: June 2016

Network lifetime is an important performance for wireless relaying systems and many relay selections have been proposed to prolong the network lifetime. However, in most cases only simulation results were given, rather than a closed form of average relay transmit‐power (ARTP) or network lifetime. In this study, the authors first give a general analytical expression of ARTP for any relay selection strategy when all relays have enough energy in amplify‐and‐forward relaying systems. To analyse the probability density function (PDF) of relay transmit‐power, they derive the constraints of probability for arbitrary possible transmit‐power. Then, they get two special PDFs, which correspond to the minimum ARTP (MinARTP) and the maximum ARTP (MaxARTP). Finally, MinARTP and MaxARTP are derived. Simulation results validate that MinARTP and MaxARTP can approximately represent the lower bound and the upper bound of ARTP for the system.
Self‐sensing estimator for micromachined electrostatic actuators and parameters’ optimisation
Authors: Li Chong , Dean Robert N. , Flowers George T.
Published: June 2016

Parallel plate actuators (PPAs) are widely used in micro‐electro‐mechanical systems. Control strategies for PPAs often require displacement and velocity feedback that may be measured with various sensing techniques, which may require additional structures or distort the steady‐state behaviour. An alternative approach of designing an estimator using the measured voltage across the PPA without additional sensing structures and distortions is proposed in this work. This novel method can improve the performance and reduce the device's footprint with full‐state (displacement and velocity) feedback information, using a series resistor. A system model using this configuration is investigated. The observability of this self‐sensing technique is analysed using a small signal model. Then, a singular value decomposition is applied to examine how to further improve the observability by choosing appropriate parameters. Simulation and numerical studies were performed which validate this method.
Controlled synthesis of monodisperse silica particles
Authors: Liang Xiao , Lian Lixian , Liu Ying , Kong Qingquan , Wang Li
Published: June 2016

Spherical silica particles with uniform size (90–520 nm) were successfully fabricated using Stöber method. The size of silica particle (fabricated from ethanol, water, ammonia and tetraethyl orthosilicate) was examined by field‐emission scanning electron microscopy. The effect of stirring rates (0–1200 rpm), reaction temperatures (12–75°C) and total volumes (80–400 0ml) on silica particle size was studied in detail. The experiment results indicate that stirring rates has no significant impact on the average size of silica particles, while higher temperature and larger total volume of reactant both result in smaller silica particles.
Effects of finiteness on the thermo-fluid-dynamics of natural convection above horizontal plates
Authors: Guha Abhijit , Sengupta Sayantan
Published: June 2016

A rigorous and systematic computational and theoretical study, the first of its kind, for the laminar natural convective flow above rectangular horizontal surfaces of various aspect ratios ϕ (from 1 to ∞) is presented. Two-dimensional computational fluid dynamic (CFD) simulations (for ϕ → ∞) and three-dimensional CFD simulations (for 1 ≤ ϕ < ∞) are performed to establish and elucidate the role of finiteness of the horizontal planform on the thermo-fluid-dynamics of natural convection. Great care is taken here to ensure grid independence and domain independence of the presented solutions. The results of the CFD simulations are compared with experimental data and similarity theory to understand how the existing simplified results fit, in the appropriate limiting cases, with the complex three-dimensional solutions revealed here. The present computational study establishes the region of a high-aspect-ratio planform over which the results of the similarity theory are approximately valid, the extent of this region depending on the Grashof number. There is, however, a region near the edge of the plate and another region near the centre of the plate (where a plume forms) in which the similarity theory results do not apply. The sizes of these non-compliance zones decrease as the Grashof number is increased. The present study also shows that the similarity velocity profile is not strictly obtained at any location over the plate because of the entrainment effect of the central plume. The 3-D CFD simulations of the present paper are coordinated to clearly reveal the separate and combined effects of three important aspects of finiteness: the presence of leading edges, the presence of planform centre, and the presence of physical corners in the planform. It is realised that the finiteness due to the presence of physical corners in the planform arises only for a finite value of ϕ in the case of 3-D CFD simulations (and not in 2-D CFD simulations or similarity theory). The presence of physical corners is related here to several significant aspects of the solution—the conversion of in-plane velocity to out-of-plane velocity near the diagonals, the star-like non-uniform distribution of surface heat flux on heated planforms, the three-dimensionality of the temperature field, and the complex spatial structure of the velocity iso-surfaces. A generic theoretical correlation for the Nusselt number is deduced for the averaged surface heat flux for various rectangular surfaces (1 ≤ ϕ < ∞) over a wide range of Grashof number. Innovative use of numerical visualization images is made to generate a comprehensive, quantitative understanding of the physical processes involved.
Rotationally resolved vibrational spectra of AsH3+X̃2A2″: Tunneling splittings studied by zero-kinetic-energy photoelectron spectroscopy
Authors: Sun Wei , Dai Zuyang , Wang Jia , Mo Yuxiang
Published: June 2016

The rotationally resolved vibrational spectra of AsH3+X̃2A2″ have been measured for the first time with vibrational energies up to 6000 cm−1 above the ground state using the zero-kinetic-energy photoelectron method. The symmetric inversion vibrational energy levels (v2+) and the corresponding rotational constants for v2+=0-15 have been determined. The tunneling splittings of the inversion vibration energy levels have been observed and are 0.8 and 37.7 (±0.5) cm−1 for the ground and the first excited vibrational states, respectively. The first adiabatic ionization energy for AsH3 was determined as 79 243.3 ± 1 cm−1. The geometric parameters of AsH3+X̃2A2″ as a function of inversion vibrational numbers have been determined, indicating that the geometric structure of the cation changes from near-planar to pyramidal with increasing inversion vibrational excitation. In addition to the experimental measurements, a two-dimensional theoretical calculation considering the two symmetric vibrational modes was performed to determine the energy levels of the symmetric inversion, which are in good agreement with the experimental results. The inversion vibrational energy levels of SbH3+X̃2A2″ have also been calculated and are found to have much smaller energy splittings than those of AsH3+X̃2A2″.
Alternative uses of a megavolt tandem accelerator for few-keV studies with ion-source SIMS monitoring
Authors: Mello S. L. A. , Codeço C. F. S. , Magnani B. F. , Sant’Anna M. M.
Published: June 2016

We increase the versatility of a tandem electrostatic accelerator by implementing simple modifications to the standard operation procedure. While keeping its ability to deliver MeV ion beams, we show that the experimental setup can (i) provide good quality ion beams in the few-keV energy range and (ii) be used to study ion-beam surface modification with simultaneous secondary ion mass spectrometry. This latter task is accomplished without using any chamber connected to the accelerator exit. We perform mass spectrometry of the few-keV anions produced in the ion source by measuring their neutral counterparts at the accelerator exit with energies up to 1.7 MeV. With an additional modification, a high-current few-keV regime is obtained, using the ion source as an irradiation chamber and the accelerator itself only as a mass spectrometer. As an example of application, we prepare a sample for the study of ion-beam assisted dewetting of a thin Au film on a Si substrate.
Effective medium theory for a system of C60 molecules
Authors: Moradi Afshin
Published: June 2016

An effective medium theory is developed to study the effective permittivity of a system of C60 molecules. We use a two-dimensional, spherical, two-fluid hydrodynamic model to describe the linear response of the π and σ electrons over the each C60 molecule. A general expression for the electromagnetic wave attenuation coefficient of the system is then deduced, and its functional dependence on the filling factor is presented. Furthermore, the dispersion characteristics of electromagnetic oscillations of the system are studied.
New structural and electronic properties of (TiO2)10
Authors: Aguilera-Granja F. , Vega A. , Balbás L. C.
Published: June 2016

We present, based on state of the art density functional theoretic calculations, a new putative ground state (GS) for the cluster (TiO2)10, which results more than 1 eV lower in energy than all those previously reported in the literature. The geometric and electronic properties of this new cluster are discussed in detail and in comparison with the rest. We analyze the implications of the new GS in the context of recent experiments of reactivity regarding oxygen exchange with gaseous CO2 in TiO2 nanostructures, and also in connection with a recent interpretation of photoelectron spectroscopic measurements of the band gap of gas phase TiO2− clusters.
Van der Waals epitaxy of functional MoO2 film on mica for flexible electronics
Authors: Ma Chun-Hao , Lin Jheng-Cyuan , Liu Heng-Jui , Do Thi Hien , Zhu Yuan-Min , Ha Thai Duy , Zhan Qian , Juang Jenh-Yih , He Qing , Arenholz Elke , Chiu Po-Wen , Chu Ying-Hao
Published: June 2016

Flexible electronics have a great potential to impact consumer electronics and with that our daily life. Currently, no direct growth of epitaxial functional oxides on commercially available flexible substrates is possible. In this study, in order to address this challenge, muscovite, a common layered oxide, is used as a flexible substrate that is chemically similar to typical functional oxides. We fabricated epitaxial MoO2 films on muscovite via pulsed laser deposition technique. A combination of X-ray diffraction and transmission electron microscopy confirms van der Waals epitaxy of the heterostructures. The electrical transport properties of MoO2 films are similar to those of the bulk. Flexible or free-standing MoO2 thin film can be obtained and serve as a template to integrate additional functional oxide layers. Our study demonstrates a remarkable concept to create flexible electronics based on functional oxides.
Atomistic modeling of the metallic-to-semiconducting phase boundaries in monolayer MoS2
Authors: Saha Dipankar , Mahapatra Santanu
Published: June 2016

Recent experimental demonstration on the coexistence of metallic and semiconducting phases in the same monolayer MoS2 crystal has attracted much attention for its use in ultra-low contact resistance-MoS2 transistors. However, the electronic structures of the metallic-to-semiconducting phase boundaries, which appear to dictate the carrier injection in such transistors, are not yet well understood. In this letter, interfacing the 2H and 1T′ polytypes appropriately, we first model the “beta” (β) and the “gamma” (γ) phase boundaries, and demonstrate good agreement with experiential results. We then apply first-principles based density functional theory to calculate the electronic structures for those optimized geometries. We further employ non equilibrium Green's function formalism to evaluate the transmission spectra and the local density of states (LDOS) in order to assess the Schottky barrier nature of the phase boundaries. Our study reveals that while the γ boundary yields p-type Schottky barrier, the β boundary leads to the distinct symmetric Schottky barrier with an atomically sharp transition region. This understanding could be useful for designing high performance transistors using phase-engineered MoS2 crystals.
Intrinsic ferromagnetic coupling in Co3O4 quantum dots activatedby graphene hybridization
Authors: Chen Lin , Hu Fengchun , Duan Hengli , Liu Qinghua , Tan Hao , Yan Wensheng , Yao Tao , Jiang Yong , Sun Zhihu , Wei Shiqiang
Published: June 2016

Activating ferromagnetic couplings of transition-metallic ions in the antiferromagnetic metal oxide semiconductors is desired for creating ferromagnetic semiconductors for spintronics applications. Here, we report intrinsic ferromagnetic coupling in a typical antiferromagnetic metal oxide Co3O4, by virtue of a hybrid structure that modifies the valence state of Co ions. The Co3O4 quantum dots exhibit ferromagnetism of 2.2 emu/g at 2 K after hybridization with reduced graphene oxide (RGO). In this hybrid structure, electron-transfer from RGO to Co3O4 occurs and Co3+ ions occupying the octahedral (Oh) positions are converted into Co2+. Then the super-exchange interactions between Co2+ ions at Td (tetrahedral) and Oh positions switch the magnetic coupling of Co2+(Td)–Co2+(Td) from antiferromagnetic to ferromagnetic. These results offer promise for tailoring the spin exchange interactions of oxide semiconductors for spintronics applications.
A study on the epitaxial Bi2Se3 thin film grown by vapor phase epitaxy
Authors: Lin Yen-Cheng , Chen Yu-Sung , Lee Chao-Chun , Wu Jen-Kai , Lee Hsin-Yen , Liang Chi-Te , Chang Yuan Huei
Published: June 2016

We report the growth of high quality Bi2Se3 thin films on Al2O3 substrates by using chemical vapor deposition. From the atomic force microscope, x-ray diffraction and transmission electron microscope measurements we found that the films are of good crystalline quality, have two distinct domains and can be grown epitaxially on the Al2O3 substrate. Carrier concentration in the sample is found to be 1.1 × 1019 cm−3 between T = 2 K to T = 300 K, and electron mobility can reach 954 cm2/V s at T = 2 K. Weak anti-localization effect is observed in the low temperature magneto-transport measurement for the sample which indicates that the thin film has topological surface state.
Molecular dynamics of nanodroplet impact: The effect of the projectile’s molecular mass on sputtering
Authors: Saiz Fernan , Gamero-Castaño Manuel
Published: June 2016

The impact of electrosprayed nanodroplets on ceramics at several km/s alters the atomic order of the target, causing sputtering, surface amorphization and cratering. The molecular mass of the projectile is known to have a strong effect on the impact phenomenology, and this article aims to rationalize this dependency using molecular dynamics. To achieve this goal, the article models the impact of four projectiles with molecular masses between 45 and 391 amu, and identical diameters and kinetic energies, 10 nm and 63 keV, striking a silicon target. In agreement with experiments, the simulations show that the number of sputtered atoms strongly increases with molecular mass. This is due to the increasing intensity of collision cascades with molecular mass: when the fixed kinetic energy of the projectile is distributed among fewer, more massive molecules, their collisions with the target produce knock-on atoms with higher energies, which in turn generate more energetic and larger numbers of secondary and tertiary knock-on atoms. The more energetic collision cascades intensify both knock-on sputtering and, upon thermalization, thermal sputtering. Besides enhancing sputtering, heavier molecules also increase the fraction of the projectile’s energy that is transferred to the target, as well as the fraction of this energy that is dissipated.
Improving optical performance of GaN nanowires grown by selective area growth homoepitaxy: Influence of substrate and nanowire dimensions
Authors: Aseev P. , Gačević Ž. , Torres-Pardo A. , González-Calbet J. M. , Calleja E.
Published: June 2016

Series of GaN nanowires (NW) with controlled diameters (160–500 nm) and heights (420–1100 nm) were homoepitaxially grown on three different templates: GaN/Si(111), GaN/AlN/Si(111), and GaN/sapphire(0001). Transmission electron microscopy reveals a strong influence of the NW diameter on dislocation filtering effect, whereas photoluminescence measurements further relate this effect to the GaN NWs near-bandgap emission efficiency. Although the templates' quality has some effects on the GaN NWs optical and structural properties, the NW diameter reduction drives the dislocation filtering effect to the point where a poor GaN template quality becomes negligible. Thus, by a proper optimization of the homoepitaxial GaN NWs growth, the propagation of dislocations into the NWs can be greatly prevented, leading to an exceptional crystal quality and a total dominance of the near-bandgap emission over sub-bandgap, defect-related lines, such as basal stacking faults and so called unknown exciton (UX) emission. In addition, a correlation between the presence of polarity inversion domain boundaries and the UX emission lines around 3.45 eV is established.
Crystal structure induced residue formation on 4H-SiC by reactive ion etching
Authors: Liu Yi-hong , Sun Yu-jun , Zhao Gao-jie , Liao Li-ming , Wang Tao , Chen Zhi-zhan
Published: June 2016

The (0001¯) C face of 4H-SiC wafer was etched by reactive ion etching in SF6/O2 plasma. The effect of etching parameters, such as work pressure, SF6:O2 ratio and etching time, on the residue formation were systematically investigated. The residue morphologies were observed by scanning electron microscopy and atomic force microscopy, respectively. The residues have spike shape and their facets are defined as {11¯02¯} crystal planes. They are formed at beginning of the etching and no new spikes are generated as prolonging etching time. Both work pressure and SF6:O2 ratio play significant role in the spike formation. The residues can be eliminated completely by increasing the SF6:O2 ratio and work pressure. On the basis of experimental results and of 4H-SiC crystal structure, the spike formation model is proposed.
Reproductive biology of a medicinally important plant Leonurus cardiaca (Lamiaceae)
Authors: Borna Fatemeh , Ahmad Nabil M. , Luo Shuming , Trethowan Richard
Published: June 2016

Motherwort (Leonurus cardiaca L.) is an annual species indigenous to central Europe and Scandinavia and has been used in traditional medicine because of its health benefits. The reproductive biology of L. cardiaca was investigated to provide a basis for the genetic improvement of secondary metabolites or extracts that could have human health benefits. L. cardiaca is self-compatible but bears protandrous flowers, which promote cross-pollination. The stigma becomes receptive 2 or 3 days after anthesis and anther dehiscence. Phenological observations revealed that the mean flowering duration was approximately 2 weeks within each inflorescence and 2 months within a plant. The timing of anthesis of flowers within each inflorescence and flowers of different inflorescences is usually synchronous, leading to the possibility of geitonogamous pollination. A high degree of synchronisation in flowering was observed among the plants within each of the populations studied. Among the populations, Khansar was the first to flower, whereas Dargaz was the last. A modified Brewbaker and Kwack (BK) medium optimised for in vitro germination of L. cardiaca pollen was used to establish a rapid and simple test that generally correlated with seed set. The optimised medium comprised 15% sucrose and 2.5% polyethylene glycol 4000. Data from staining with iodine–potassium iodide solution (IKI) and Alexander’s stain were positively correlated with in vitro germination and, therefore, could be used in rapid pollen-viability assays for L. cardiaca.
Insights into feral goat movement in Australia using dynamic Brownian Bridges for movement analysis
Authors: Lethbridge Mark R.
Published: June 2016

Movement analyses were conducted for 50 goats across southern Australia using GPS satellite collars. A radio or satellite-tracked animal used to direct culling operations is generally called a ‘Judas’ animal. Goats used as ‘Judas’ animals in control operations were compared with non-‘Judas’ goats in the states of South Australia and Victoria, respectively. Their movement in two land systems were also compared. Dynamic Brownian Bridges Movement Models were used to calculate home ranges (95% utilisation areas). Changes in movement behaviour were identified to partition sedentary behaviour from long-distance movement events, defined here as ranging. Eleven goats exhibited ranging behaviour and moved from 9 to 33 km between their home ranges. After partitioning, their home ranges varied from 1.97 to 223.8 km2. In this study in the Southern Australian Mallee regions, non-‘Judas’ goats had significantly smaller home ranges than ‘Judas’ goats. However, no significant differences were found in the ranging distances between non-‘Judas’ goats and ‘Judas’ goats. Understanding these two distinct forms of goat movement is important in the planning and budgeting of removal operations. To demonstrate this a simple goat management decision tool is used to illustrate the biases that can result in the expected hours of removal operations when the assumptions about goat movement are ill-defined.
Insurance coverage of customers induces dishonesty of sellers in markets for credence goods
Authors: Kerschbamer Rudolf , Neururer Daniel , Sutter Matthias
Published: June 2016

Significance

Markets for credence goods are characterized by informational asymmetries between sellers and customers, creating strong incentives for fraudulent seller behavior. Prime examples for credence goods are repair services or medical treatments. Empirical evidence suggests that sellers’ fraud imposes an excess burden of billions of dollars annually to customers. We examine in a natural field experiment how customers’ insurance coverage exacerbates inefficiencies in the provision of credence goods. Specifically, we study how computer repair shops exploit customers’ insurance. In a control treatment, the average repair price is about EUR 70, but increases by 80% when the customer has insurance for repair costs. We can show that the latter increase is mainly due to overprovision of parts and fraudulent overcharging of working time.
Distinct oligoclonal band antibodies in multiple sclerosis recognize ubiquitous self-proteins
Authors: Brändle Simone M. , Obermeier Birgit , Senel Makbule , Bruder Jessica , Mentele Reinhard , Khademi Mohsen , Olsson Tomas , Tumani Hayrettin , Kristoferitsch Wolfgang , Lottspeich Friedrich , Wekerle Hartmut , Hohlfeld Reinhard , Dornmair Klaus
Published: June 2016

Significance

Oligoclonal bands (OCBs) of the cerebrospinal fluid (CSF) are a hallmark of multiple sclerosis (MS). They are expanded antibody species that are detectable in >95% of patients. Because several OCB and polyclonal antibodies are present in a CSF sample, it was for technical reasons thus far not possible to isolate distinct OCBs and identify their antigens. Here we combined refined biochemical analysis, proteomics, and transcriptomics to molecularly characterize distinct OCB antibodies. We produced six recombinant OCB antibodies and characterized three autoantigens. All of them were ubiquitous intracellular proteins, not specific to brain tissue. This finding indicates that in MS, part of the OCBs do not directly mediate tissue destruction, but rather, indicate a secondary immune response.