bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron-transfer reactions of halogenated electrophiles: a different look into the nature of halogen bonding
Authors: Rosokha Sergiy V.
Published: March 2017

The rates of oxidation of ferrocene derivatives by brominated molecules R-Br (CBr3CN, CBr4, CBr3NO2, CBr3COCBr3, CBr3CONH2, CBr3F, and CBr3H) were consistent with the predictions of the outer-sphere dissociative electron-transfer theory. The similar redox-reactions of the R-Br electrophiles with the typical halogen-bond acceptors tetramethyl-p-phenylenediamine (TMPD) or iodide were much faster than calculated using the same model. The fast redox-processes in these systems were related to the involvement of the transient halogen-bonded [R-Br, TMPD] or [R-Br, I−] complexes in which barriers for electron transfer were lowered by the strong electronic coupling of reactants. The Mulliken–Hush treatment of the spectral and structural characteristics of the [R-Br, TMPD] or [R-Br, I−] complexes corroborated the values of coupling elements,Hab, of 0.2–0.5 eV implied by the kinetic data. The Natural Bond Orbital analysis of these complexes indicated a noticeable donor/acceptor charge transfer, Δq, of 0.03–0.09 ē. TheHaband Δqvalues in the [R-Br, TMPD] and [R-Br, I−] complexes (which are similar to those in the traditional charge-transfer associates) indicate significant contribution of charge-transfer (weakly-covalent) interaction to halogen bonding. The decrease of the barrier for electron transfer between the halogen-bonded reactants demonstrated in the current work points out that halogen bonding should be taken into account in the mechanistic analysis of the reactions of halogenated species.
Reusable cobalt-phthalocyanine in water: efficient catalytic aerobic oxidative coupling of thiols to construct S–N/S–S bonds
Authors: Dou Yingchao , Huang Xin , Wang Hao , Yang Liting , Li Heng , Yuan Bingxin , Yang Guanyu
Published: March 2017

Reusable Co-catalyzed coupling of thiols to synthesize S–N/S–S bonds in water.
Dynamic deviation memory polynomial model for digital predistortion
Authors: Song Bin , He Songbai , Peng Jun , Zhao Yatao
Published: March 2017

A dynamic deviation memory polynomial (DDMP) model for digital predistortion is proposed to compensate the non‐linear distortion of the power amplifier. It is based on the memory polynomial model and dynamic deviation reduction‐based Volterra (DDRV) model. Compared to the DDRV model, the proposed model shows better modelling accuracy under the same complexity. The effectiveness of the DDMP model has been verified by simulation and experiment results.
Approach of generation fleet voltage schedule validation for power system voltage stability
Authors: Javadi Milad , Wu Di , Jiang John N.
Published: March 2017

In this study, the authors present an approach to validate the voltage schedule for operation of generation fleet within a balancing area managed by Independent System Operators/Regional Transmission Organizations or a balancing authority. An appropriate voltage schedule is an important requirement for the generator operators to maintain adequate VAR reserves and ensure the voltage stability. Based on current industry requirements, an empirical approach is developed to validate the voltage schedule following significant variations in generation pattern and load pattern, as possible results of integration of power generation from variable renewable resources or responsive demand. The approach can validate voltage schedule of generator fleet and transfer buses connected to the generator buses while monitoring the ranges of set‐point voltages and VAR levels of the generators. Moreover, they use the approach to investigate the impact of variations in the generation and load patterns on the voltage schedule in a real power grid. The findings are useful for an improved management of voltage stability, voltage schedule validation, and estimation of reactive power adequacy for operation support of future power grid with high penetration of renewables and responsive demands.
Dynamic and adaptive reconfiguration of electrical distribution system including renewables applying stochastic model predictive control
Authors: Rahmani‐Andebili Mehdi
Published: March 2017

In this study, the structure of an electrical distribution network, which includes several electrical distribution feeders, is adaptively and dynamically reconfigured to minimise the daily operation cost of system that is under control of a local distribution company. Herein, for the first time, stochastic model predictive control (MPC) concept is applied in the problem to have dynamic and adaptability futures in the optimisation problem and to deal with the uncertainty and variability issues of renewable energy resources. The daily operation cost of distribution system comprises hourly energy loss cost of electrical feeders and switching cost of initially open and close switches installed on each feeder. The numerical study shows the existence of notable potential in reconfiguration of distribution system for energy loss and operation cost reduction. In addition, it is demonstrated that applying MPC in the optimal reconfiguration of distribution system results in better consequences in the presence of variable power of renewables. Moreover, it is proven that application of MPC in the problem increases the robustness and resiliency of optimisation procedure with respect to the prediction errors due to dynamic and adaptability characteristics of MPC.
Filters that mitigate waveform modulation of radar clutter
Authors: O'Connor Alan C. , Kantor Joshua M. , Jakabosky John
Published: March 2017

Moving target indication (MTI) radars will require modified signal processing to be able to employ pulse‐to‐pulse agile waveforms. The main problem with conventional processing is that matched‐filter pulse compression leads to range‐sidelobe modulation (RSM) of clutter. Due to the fact that range sidelobes differ on each pulse, clutter energy that leaks into these sidelobes cannot be cancelled by subsequent processing. This study derives a figure‐of‐merit for pulse‐compression filters that quantifies the signal‐to‐interference‐plus‐noise ratio (SINR) loss that results from RSM. Optimising this figure‐of‐merit results in sets of filters that mitigate RSM by producing matched sidelobes. The proposed filters are compared to low‐sidelobe mismatch filters designed separately for each pulse. Simulation results indicate that an MTI radar could achieve a 5–10 dB improvement in SINR by using the proposed filters instead of low‐sidelobe filters.
Degradation effects on single crystalline silicon photovoltaic modules subjected to high impulse‐voltages
Authors: Naxakis Ioannis , Christodoulou Christos , Perraki Vasiliki , Pyrgioti Eleytheria
Published: March 2017

Scope of the current study is to examine the electrical characteristics of photovoltaic (PV) modules after being subjected to high impulse voltages, which are usually generated by lightning or switching surges. Tests were conducted at the High Voltage Laboratory of the University of Patras in Greece on PV modules of 5 and 195 Wp derived from different manufacturers, by performing various stress scenarios. The I‐V and P‐V characteristic curves of the examined modules, before and after the impulse voltage stress tests, are compared with each other considering the modules' ability to maintain their nominal electrical characteristics. After certain periods of time, the electrical performances of the stressed modules are examined again in order to ensure whether they regain some or all of their properties in case of prior differentiation. The experimental results are compared with theoretical estimations, so as to confirm the rightness of the presented procedure.
Oxidative degradation and morphological properties of gamma‐irradiated isotactic polypropylene films
Authors: Mouaci Sarah , Saidi Mohamed , Saidi‐Amroun Nadia
Published: March 2017

Isotactic polypropylene (iPP) films of 25 μm thickness were subjected to gamma‐ray irradiation for different doses (30, 60, 90 and 100 kGy) at ambient atmosphere and both molecular modifications and surface properties have been investigated by Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM), respectively. The occurrence of the oxidation process is identified and quantified by the FTIR. In addition, it is found that the carbonyl index increases with the absorbed dose which confirms that the irradiation process induces the diffusion of the oxygen into the iPP matrix. The AFM image (for virgin and higher dose irradiated samples) showed a dramatic change in the surface topography. The gamma radiation induces the formation of the nanostructured iPP surface. The roughness of the polymer surface, measured by AFM, increases after gamma irradiation. These results revealed that the oxidative degradation may be correlated with the morphological properties.
Mechanochemical Grinding Diels–Alder Reaction: Highly Efficient and Rapid Access to Bi-, Tri-, and Tetracyclic Systems
Authors: Peddinti Rama , Agarwal Jyoti , Rani Rashmi
Published: March 2017

Grinding of various electron-deficient dienophiles with diverse dienes in a pestle and mortar for 1–15 minutes afforded the corresponding Diels–Alder adducts in quantitative yields under catalyst-free and solvent-free conditions, without the necessity for any purification steps.
Frequency of Chromosomal Abnormalities in Products of Conception
Authors: Paula Carolina Maria Marques de , Ramos Mariana Gontijo , Costa Helena B. B. L. Martins da , Andrade Cyntia Roberta Almeida , Coxir Sarah Abreu , Penna Maria Lectícia Firpe , Teles Thaís Mesquita Alves
Published: March 2017

Purpose To describe the frequencies of chromosomal abnormalities found in abortion material, and to observe its correlation to maternal age.

Methods A retrospective study was conducted based on data obtained from the databank of a medical genetics laboratory in Belo Horizonte, MG, Brazil. A total of 884 results from products of conception analysis were included, 204 of which were analyzed by cytogenetics, and 680 by molecular biology based on quantitative fluorescence polymerase chain reaction (QF-PCR). The frequency of individual chromosomal aberrations and the relationship between the presence of anomalies and maternal age were also evaluated.

Results The conventional cytogenetics technique was able to detect 52% of normal and 48% of abnormal results in the analyzed material. Quantitative fluorescence polymerase chain reaction revealed 60% of normal and 40% of abnormal results from the samples evaluated by this method. The presence of trisomy 15 was detected only by cytogenetics, as it was not included in the QF-PCR routine investigation in the laboratory. A significant increase in abnormal results was observed among women aged 35 years or older compared with younger women (p = 0.02).

Conclusion Chromosomal aberrations are still a major cause of spontaneous abortion, and the conventional cytogenetics technique is efficient for miscarriage material analysis, but molecular methods such as QF-PCR are adequate complementary strategies to detect the major chromosomal anomalies, leading to technical reports with reliable results.
Evaluation of the 2015 AGA guidelines on pancreatic cystic neoplasms in a large surgically confirmed multicenter cohort
Authors: Ge Phillip , Muthusamy V. , Gaddam Srinivas , Jaiyeola Diana-Marie , Kim Stephen , Sedarat Alireza , Donahue Timothy , Hosford Lindsay , Wilson Robert , Grande David , Keswani Rajesh , Kushnir Vladimir , Mullady Daniel , Edmundowicz Steven , Early Dayna , Komanduri Srinadh , Wani Sachin , Watson Rabindra
Published: March 2017

Absract

Background and study aims The American Gastroenterological Association (AGA) recently published guidelines for the management of asymptomatic pancreatic cystic neoplasms (PCNs). We aimed to evaluate the diagnostic characteristics of the AGA guidelines in appropriately recommending surgery for malignant PCNs.

Patients and methods A retrospective multicenter study was performed of patients who underwent endoscopic ultrasound (EUS) for evaluation of PCNs who ultimately underwent surgical resection from 2004 – 2014. Demographics, EUS characteristics, fine-needle aspiration (FNA) results, type of resection, and final pathologic diagnosis were recorded. Patients were categorized into 2 groups (surgery or surveillance) based on what the AGA guidelines would have recommended. Performance characteristics for the diagnosis of cancer or high-grade dysplasia (HGD) on surgical pathology were calculated.

Results Three hundred patients underwent surgical resection for PCNs, of whom the AGA guidelines would have recommended surgery in 121 (40.3 %) and surveillance in 179 (59.7 %) patients. Among patients recommended for surgery, 45 (37.2 %) had cancer, whereas 76 (62.8 %) had no cancer/HGD. Among patients recommended for surveillance, 170 (95.0 %) had no cancer/HGD; however, 9 (5.0 %) patients had cancer that would have been missed. For the finding of cancer/HGD on surgical pathology, the AGA guidelines had 83.3 % sensitivity (95 % CI 70.7 – 92.1), 69.1 % specificity (95 % CI 62.9 – 74.8), 37.2 % positive predictive value (95 % CI 28.6 – 46.4), 95.0 % negative predictive value (95 % CI 90.7 – 97.7), and 71.7 % accuracy (95 % CI 67.4 – 74.6).

Conclusions The 2015 AGA guidelines would have resulted in 60 % fewer patients being referred for surgical resection, and accurately recommended surveillance in 95 % of patients with asymptomatic PCNs. Future prospective studies are required to validate these guidelines.

Meeting presentations: Presented in part at Digestive Diseases Week 2016
Approximate but accurate quantum dynamics from the Mori formalism. II. Equilibrium time correlation functions
Authors: Montoya-Castillo Andrés , Reichman David R.
Published: March 2017

The ability to efficiently and accurately calculate equilibrium time correlation functions of many-body condensed phase quantum systems is one of the outstanding problems in theoretical chemistry. The Nakajima-Zwanzig-Mori formalism coupled to the self-consistent solution of the memory kernel has recently proven to be highly successful for the computation of nonequilibrium dynamical averages. Here, we extend this formalism to treat symmetrized equilibrium time correlation functions for the spin-boson model. Following the first paper in this series [A. Montoya-Castillo and D. R. Reichman, J. Chem. Phys. 144, 184104 (2016)], we use a Dyson-type expansion of the projected propagator to obtain a self-consistent solution for the memory kernel that requires only the calculation of normally evolved auxiliary kernels. We employ the approximate mean-field Ehrenfest method to demonstrate the feasibility of this approach. Via comparison with numerically exact results for the correlation function Czz(t)=Re⟨σz(0)σz(t)⟩, we show that the current scheme affords remarkable boosts in accuracy and efficiency over bare Ehrenfest dynamics. We further explore the sensitivity of the resulting dynamics to the choice of kernel closures and the accuracy of the initial canonical density operator.
Born-Oppenheimer molecular dynamics studies of Pb(ii) micro hydrated gas phase clusters
Authors: León-Pimentel C. I. , Amaro-Estrada J. I. , Saint-Martin H. , Ramírez-Solís A.
Published: March 2017

In this work, a theoretical investigation was made to assess the coordination properties of Pb(ii) in [Pb(H2O)n]2+ clusters, with n = 4, 6, 8, 12, and 29, as well as to study proton transfer events, by means of Born-Oppenheimer molecular dynamics simulations at the B3LYP/aug-cc-pVDZ-pp/6-311G level of theory, that were calibrated in comparison with B3LYP/aug-cc-pVDZ-PP/aug-cc-pVDZ calculations. Hemidirected configurations were found in all cases; the radial distribution functions (RDFs) produced well defined first hydration shells (FHSs) for n = 4,6,8, and 12, that resulted in a coordination number CN = 4, whereas a clear-cut FHS was not found for n = 29 because the RDF did not have a vacant region after the first maximum; however, three water molecules remained directly interacting with the Pb ion for the whole simulation, while six others stayed at average distances shorter than 4 Å but dynamically getting closer and farther, thus producing a CN ranging from 6 to 9, depending on the criterion used to define the first hydration shell. In agreement with experimental data and previous calculations, proton transfer events were observed for n≤8 but not for n≥12. For an event to occur, a water molecule in the second hydration shell had to make a single hydrogen bond with a water molecule in the first hydration shell.
Perspective: Explicitly correlated electronic structure theory for complex
systems
Authors: Grüneis Andreas , Hirata So , Ohnishi Yu-ya , Ten-no Seiichiro
Published: March 2017

The explicitly correlated approach is one of the most important breakthroughs in ab initio electronic structure theory, providing arguably the most compact, accurate, and efficient ansatz for describing the correlated motion of electrons. Since Hylleraas first used an explicitly correlated wave function for the He atom in 1929, numerous attempts have been made to tackle the significant challenges involved in constructing practical explicitly correlated methods that are applicable to larger systems. These include identifying suitable mathematical forms of a correlated wave function and an efficient evaluation of many-electron integrals. R12 theory, which employs the resolution of the identity approximation, emerged in 1985, followed by the introduction of novel correlation factors and wave function ansätze, leading to the establishment of F12 theory in the 2000s. Rapid progress in recent years has significantly extended the application range of explicitly correlated theory, offering the potential of an accurate wave-function treatment of complex systems such as photosystems and semiconductors. This perspective surveys explicitly correlated electronic structure theory, with an emphasis on recent stochastic and deterministic approaches that hold significant promise for applications to large and complex systems including solids.
Lifshitz topological transitions, induced by doping and deformation in single-crystal bismuth wires
Authors: Nikolaeva A. A. , Konopko L. A. , Huber T. E. , Kobylianskaya A. K. , Para Gh. I.
Published: March 2017

The features associated with the manifestation of Lifshitz electron topological transitions (ETT) in glass-insulated bismuth wires upon qualitative changes to the topology of the Fermi surface are investigated. The variation of the energy spectrum parameters was implemented by doping Bi with an acceptor impurity Sn and using elastic strain of up to 2%, relative to the elongation in the weakly-doped p-type Bi wires. Pure and doped glass-insulated single-crystal bismuth with different diameters and (1011) orientations along the axis were prepared by the Ulitovsky liquid phase casting method. For the first time, ETT-induced anomalies are observed along the temperature dependences of the thermoemf α(T) as triple-changes of the α sign (given heavy doping of Bi wires with an acceptor impurity Sn). The concentration and energy position of the Σ-band given a high degree of bismuth doping with Sn was assessed using the Shubnikov-de Haas effect oscillations, which were detected both from L-electrons and from T-holes in magnetic fields of up to 14 T. It is shown that the Lifshitz electron-topological transitions with elastic deformation of weakly-doped p-type Bi wires are accompanied by anomalies along the deformation dependences of the thermoemf at low temperatures. The effect is interpreted in terms of the formation of a selective scattering channel of L-carriers into the T-band with a high density of states, which is in good agreement with existing theoretical ETT models.
A reciprocity law and the skew Pieri rule for the symplectic group
Authors: Howe Roger , Lávička Roman , Lee Soo Teck , Souček Vladimír
Published: March 2017

We use the theory of skew duality to show that decomposing the tensor product of k irreducible representations of the symplectic group Sp2m=Sp2m(ℂ) is equivalent to branching from Sp2n to Sp2n1×⋯×Sp2nk, where n,n1,…,nk are positive integers such that n=n1+⋯+nk and the njs depend on m as well as the representations in the tensor product. Using this result and a work of Lepowsky, we obtain a skew Pieri rule for Sp2m, i.e., a description of the irreducible decomposition of the tensor product of an irreducible representation of the symplectic group Sp2m with a fundamental representation.
Two-stage kinetics of field-induced aggregation of medium-sized magnetic nanoparticles
Authors: Ezzaier H. , Alves Marins J. , Razvin I. , Abbas M. , Ben Haj Amara A. , Zubarev A. , Kuzhir P.
Published: March 2017

The present paper is focused on the theoretical and experimental study of the kinetics of field-induced aggregation of magnetic nanoparticles of a size range of 20-100 nm. Our results demonstrate that (a) in polydisperse suspensions, the largest particles could play a role of the centers of nucleation for smaller particles during the earliest heterogeneous nucleation stage; (b) an intermediate stage of the aggregate growth (due to diffusion and migration of individual nanoparticles towards the aggregates) is weakly influenced by the magnetic field strength, at least at high supersaturation; (c) the stage of direct coalescence of drop-like aggregates (occurring under magnetic attraction between them) plays a dominant role at the intermediate and late stages of the phase separation, with the time scale decreasing as a square of the aggregate magnetization.
Saturated film boiling at various gravity levels under the influence of electrohydrodynamic forces
Authors: Pandey Vinod , Biswas Gautam , Dalal Amaresh
Published: March 2017

The present work is focused on the analyses of the bubble growth and heat transfer characteristics in saturated film boiling at various levels of gravity. In addition to this, the occurrence of self-similarity in interface structures during the bubble growth is examined. The phenomenon of bubble growth is strongly influenced by the buoyant forces due to gravity and its dominant effect is found to be replaced by the electrohydrodynamic forces in reduced gravity conditions. The decrease in gravitational acceleration results in increasing the characteristic wavelength and time scale. The bubble volume and maximum height before pinch-off thus increase enormously as the gravity value is reduced. The bubble pinch-off velocity is found to be decreased significantly in the case of reduced gravity condition. Heat transfer rate deteriorates in reduced gravity conditions which can be recovered by the externally imposed electric field. The dominance of electric field on the heat transfer rate is found to be more in reduced gravity condition. However, as the value of imposed electric field is enhanced, the difference in the effect of increasing heat flux tends to reduce.
How thermal stress alters the confinement of polymers vitrificated in nanopores
Authors: Teng Chao , Li Linling , Wang Yong , Wang Rong , Chen Wei , Wang Xiaoliang , Xue Gi
Published: March 2017

Understanding and controlling the glass transition temperature (Tg) and dynamics of polymers in confined geometries are of significance in both academia and industry. Here, we investigate how the thermal stress induced by a mismatch in the coefficient of thermal expansion affects the Tg behavior of polystyrene (PS) nanorods located inside cylindrical alumina nanopores. The size effects and molecular weight dependence of the Tg are also studied. A multi-step relaxation process was employed to study the relationship between thermal stress and cooling rate. At fast cooling rates, the imparted thermal stress would overcome the yield stress of PS and peel chains off the pore walls, while at slow cooling rates, chains are kept in contact with the pore walls due to timely dissipation of the produced thermal stress during vitrification. In smaller nanopores, more PS chains closely contact with pore walls, then stronger internal thermal stress would be generated between core and shell of PS nanorod, which results in a larger deviation between two Tgs. The core part of PS shows lower Tg than bulk value, which can induce faster dynamics in the center region. A complex and important role stress plays is supposed in complex confinement condition, e.g., in nanopores, during vitrification.
High-throughput atomic force microscopes operating in parallel
Authors: Sadeghian Hamed , Herfst Rodolf , Dekker Bert , Winters Jasper , Bijnagte Tom , Rijnbeek Ramon
Published: March 2017

Atomic force microscopy (AFM) is an essential nanoinstrument technique for several applications such as cell biology and nanoelectronics metrology and inspection. The need for statistically significant sample sizes means that data collection can be an extremely lengthy process in AFM. The use of a single AFM instrument is known for its very low speed and not being suitable for scanning large areas, resulting in a very-low-throughput measurement. We address this challenge by parallelizing AFM instruments. The parallelization is achieved by miniaturizing the AFM instrument and operating many of them simultaneously. This instrument has the advantages that each miniaturized AFM can be operated independently and that the advances in the field of AFM, both in terms of speed and imaging modalities, can be implemented more easily. Moreover, a parallel AFM instrument also allows one to measure several physical parameters simultaneously; while one instrument measures nano-scale topography, another instrument can measure mechanical, electrical, or thermal properties, making it a lab-on-an-instrument. In this paper, a proof of principle of such a parallel AFM instrument has been demonstrated by analyzing the topography of large samples such as semiconductor wafers. This nanoinstrument provides new research opportunities in the nanometrology of wafers and nanolithography masks by enabling real die-to-die and wafer-level measurements and in cell biology by measuring the nano-scale properties of a large number of cells.
Process- and optoelectronic-control of NiOx thin films deposited by reactive high power impulse magnetron sputtering
Authors: Keraudy Julien , Delfour-Peyrethon Brice , Ferrec Axel , Garcia Molleja Javier , Richard-Plouet Mireille , Payen Christophe , Hamon Jonathan , Corraze Benoît , Goullet Antoine , Jouan Pierre-Yves
Published: March 2017

In this contribution, based on the analyses of the discharge behavior as well as final properties of the deposited Ni-O films during reactive high power impulse magnetron sputtering discharge, we have demonstrated that monitoring the oxygen flow rate leads to 4 different regimes of discharge. Tuning the oxygen partial pressure allows deposition of a large range of chemical compositions from pure nickel to nickel-deficient NiOx (x > 1) in the poisoned mode. Investigation of the plasma dynamics by time-resolved optical emission spectroscopy suggests that the discharge behavior in the poisoned mode principally comes from the higher contribution of both oxygen and argon ions in the total ionic current, leading to a change in the ion induced secondary electron emission coefficient. Additionally, material characterizations have revealed that optoelectronic properties of NiOx films can be easily tuned by adjusting the O/Ni ratio, which is influenced by the change of the oxygen flow rate. Stoichiometric NiO films (O/Ni ratio ∼ 1) are transparent in the visible range with a transmittance ∼80% and insulating as expected with an electrical resistivity ∼106 Ω cm. On the other hand, increasing the O/Ni > 1 leads to the deposition of more conductive coating (ρ ∼ 10 Ω cm) films with a lower transmittance ∼ 50%. These optoelectronic evolutions are accompanied by a band-gap narrowing 3.65 to 3.37 eV originating from the introduction of acceptor states between the Fermi level and the valence band maximum. In addition, our analysis has demonstrated that nickel vacancies are homogeneously distributed over the film thickness, explaining the p-type of the films.
Magnetic force driven magnetoelectric effect in Mn-Zn-ferrite/PZT composites
Authors: Zhang Ru , Jin Lei , Wu Gaojian , Zhang Ning
Published: March 2017

Several magnetoelectric devices with different structures were prepared using Mn-Zn-ferrite/PZT composite. Its magnetoelectric effect, which arose from piezoelectric effects driven by magnetic force between ferromagnets, has been studied. Experiments showed that the magnetoelectric effects in these devices are much stronger than that observed from the samples relied on magnetostrictive effect. Additionally, the magnetoelectric effect obtained from the devices based on bending piezoelectric effect at resonant point is about one order of magnitude larger than that resulted from ones that rely on stretch mode. Furthermore, magnetoelectric voltage coefficient as high as 7 V cm−1 Oe−1 with zero bias magnetic field was observed in the device with cantilever structure, which was also based on bending piezoelectric effect.
Communication: Calculations of the (2 × 1)-O reconstruction kinetics on Cu(110)
Authors: Lian Xin , Xiao Penghao , Liu Renlong , Henkelman Graeme
Published: March 2017

Density functional theory calculations are used to study the elementary processes of the formation of the (2 × 1)-O reconstruction on the Cu(110) surface. The (2 × 1)-O reconstruction requires additional Cu atoms to form Cu–O rows on top of the surface. Both terrace and step sites are considered as the source of Cu adatoms. On terraces, adsorbed oxygen induces the ejection of Cu atoms to form –O–Cu–O– units, leaving Cu vacancies behind. The barrier for subsequent unit growth, however, is prohibitively high. Cu(110) step sites are also considered as a source of Cu atoms. Dissociated oxygen triggers the formation of stable Cu–O chains along the [001] step edges. This process, however, blocks the diffusion of Cu atoms so that it is not a viable mechanism for the (2 × 1)-O reconstruction. Oxygen adsorption on the [11¯0] edges also allows the nucleation of [001] oriented Cu–O rows. The short Cu–O rows act as diffusion channels for Cu atoms that detach from the step, which append to the end of the Cu–O chains. Our calculations of the formation of the (2 × 1)-O phase on Cu(110) provide a mechanistic description of the experimentally observed reconstruction.
Social rank and reproductive performance in a herd of farmed red deer females (Cervus elaphus)
Authors: Villagrán M. , Alvarez L. , Ungerfeld R.
Published: March 2017

Hierarchical relationships between individuals determine unequal access to recourses like food and individuals of the other gender, resulting in a higher reproductive success of high-social ranked individuals. Environmental conditions and food availability may determine how strong these effects are. The aim of this work was to determine if social rank of farmed red deer females affect the reproductive results of a hormonal oestrous synchronisation treatment with ad libitum food. The studied responses included the time to oestrus onset, percentage of females that came into oestrus, conception and calving rates, gestation length, and calf gender. The study was performed during autumn on a research farm located in Mexico (20°36ʹ N, 99°55ʹ W). Forty-nine adult red deer females were assigned to two replications of 21 and 28 animals respectively and were allocated into independent paddocks with ad libitum food and water availability. Oestrous cycles were synchronised with a traditional protocol of intravaginal devices impregnated with progesterone. Agonistic behaviours between females were recorded (total = 1626 interactions), hierarchical position (Success Index = SI) of each animal was calculated and individuals were categorised as high (n = 13), medium (n = 20) or low-ranked (n = 16) individuals. Reproductive data were recorded during the 5 days after the oestrous synchronisation treatment and during the calving period. Any of the recorded responses differ between HR, MR and LR females. Female SI, age and bodyweight were not related with the probability of coming into oestrus, result pregnant, and giving birth to a male calf. Thirty-seven (78.5%) females of this study gave birth. From these calves, 15 were males and 22 were females. Due to high percentage of females in oestrus that gave birth (85.7%), it was not possible to detect the relationship between female SI, age, and bodyweight with the conception rate. Female SI, age and bodyweight were unrelated to time to oestrus onset (r2 = 0.09; P = 0.17), and to gestation length (r2 = 0.10; P = 0.20). In conclusion, with ad libitum high quality food, the social rank of red deer hinds did not affect the time to oestrus onset, percentage of females that came into oestrus, gestation length, calving and conception rates, and offspring sex ratio after an oestrous synchronisation hormonal treatment.
Fission yeast myosin I facilitates PI(4,5)P
2
-mediated anchoring of cytoplasmic dynein to the cortex
Authors: Thankachan Jerrin Mathew , Nuthalapati Stephen Sukumar , Addanki Tirumala Nireekshit , Ananthanarayanan Vaishnavi
Published: March 2017

Significance

Molecular motors perform a variety of functions such as muscle movement and nuclear positioning during cell division. One such motor protein, cytoplasmic dynein, is responsible for oscillations of the nucleus during meiosis of the unicellular eukaryote, fission yeast. In this study, we used genetics, live-cell fluorescence microscopy, and image processing to identify the key players that keep dynein at the cortex while it performs the function of back-and-forth nuclear movement by producing force on the microtubule. We discovered that the membrane phospholipid PI(4,5)P
2
and, surprisingly, the myosin I motor Myo1 are both indispensable for nuclear oscillations in fission yeast. This study thus demonstrates one of the few instances of interplay between different classes of motor proteins in the cell.
Optimal run-and-tumble–based transportation of a Janus particle with active steering
Authors: Mano Tomoyuki , Delfau Jean-Baptiste , Iwasawa Junichiro , Sano Masaki
Published: March 2017

Significance

Commanding the swimming of micrometric objects subjected to thermal agitation is always challenging for both artificial and living systems. Now, artificial swimmers can be designed with self-propelling force that can be tuned at will. However, orienting such small particles to an arbitrary direction requires counterbalancing the random rotational diffusion. Here, we introduce a simple concept to reorient artificial swimmers, granting them a motion similar to the run-and-tumbling behavior of
Escherichia coli
. We show it using Janus particles with asymmetric surface coating and moving under an ac electric field. Moreover, we determine the optimal strategy and compare it with biological swimmers. Our results encourage additional investigation into dynamical behavior of colloidal particles as well as application to microscopic devices.
Inhibition of atherogenesis by the COP9 signalosome subunit 5 in vivo
Authors: Asare Yaw , Ommer Miriam , Azombo Florence. A. , Alampour-Rajabi Setareh , Sternkopf Marieke , Sanati Maryam , Gijbels Marion J. , Schmitz Corinna , Sinitski Dzmitry , Tilstam Pathricia V. , Lue Hongqi , Gessner André , Lange Denise , Schmid Johannes A. , Weber Christian , Dichgans Martin , Jankowski Joachim , Pardi Ruggero , de Winther Menno P. J. , Noels Heidi , Bernhagen Jürgen
Published: March 2017

Significance

Atherosclerosis is an inflammatory condition of the artery wall and main cause of myocardial infarction and stroke. Inflammatory processes evoking atherogenic lesions involve NF‐κB–dependent endothelial-cell activation and monocyte/macrophage recruitment. Constitutive photomorphogenesis 9 (COP9) signalosome (CSN) subunit 5 (CSN5) and the CSN control cullin/RING E3 ligase-dependent degradation of cell-cycle regulators and inhibitor of κB‐α by cleaving neural precursor cell-expressed, developmentally down-regulated-8 (NEDD8) from cullins. CSN5 promotes tumorigenesis in humans. We generated a conditional KO mouse in which macrophage/granulocyte-CSN5 is deleted. We show that CSN5 suppresses macrophage inflammation and that mice lacking myeloid CSN5 develop larger atherosclerotic lesions. The NEDDylation inhibitor MLN4924 attenuates early atherosclerosis and inhibits inflammation in macrophages and endothelial cells. With MLN4924 in clinical trials, deNEDDylation approaches may qualify as therapeutics to reduce early-stage atherogenesis.
Hormone and receptor interplay in the regulation of mosquito lipid metabolism
Authors: Wang Xueli , Hou Yuan , Saha Tusar T. , Pei Gaofeng , Raikhel Alexander S. , Zou Zhen
Published: March 2017

Significance

Mosquitoes require a blood meal to reproduce and by blood feeding transmit some of the most dangerous human diseases. Female mosquitoes have extremely high metabolism, and the elucidation of regulatory pathways coordinating reproductive and metabolic events is essential. RNAi of the juvenile hormone receptor Methoprene-tolerant (Met) promoted triacylglycerol (TAG) catabolism and β-oxidation and diminished TAG levels, whereas ecdysone receptor (EcR) RNAi had an opposite effect. Hepatocyte nuclear factor 4 (HNF4) directly regulated TAG catabolism and β-oxidation genes, and its RNAi silencing phenocopied EcR RNAi. The expression of the
HNF4
gene was downregulated by Met and activated by EcR and Target of rapamycin. Thus, HNF4 mediates hormonal and nutritional signaling of lipid metabolism regulation in reproducing female
Aedes aegypti
mosquitoes.
Parasitophorous vacuole poration precedes its rupture and rapid host erythrocyte cytoskeleton collapse in
Plasmodium falciparum
egress
Authors: Hale Victoria L. , Watermeyer Jean M. , Hackett Fiona , Vizcay-Barrena Gema , van Ooij Christiaan , Thomas James A. , Spink Matthew C. , Harkiolaki Maria , Duke Elizabeth , Fleck Roland A. , Blackman Michael J. , Saibil Helen R.
Published: March 2017

Significance

Malaria parasites develop within red blood cells inside a membrane-enclosed parasitophorous vacuole. An essential step in their life cycle is the exit of mature parasites from the blood cell, a multistage process termed egress. To do this, the parasites orchestrate a highly regulated sequence of membrane permeabilization and breakage steps culminating in the explosive release of parasites for a new round of infection. Here, we describe a previously unidentified permeabilization of the vacuolar membrane at the start of egress, preceding membrane rupture, suggesting a new initiation step in egress. We also show that, in the final minutes of egress, the blood cell membrane abruptly loses its structural rigidity and collapses around the parasites, showing a precise timing for cytoskeletal breakdown.
Loss of LMOD1 impairs smooth muscle cytocontractility and causes megacystis microcolon intestinal hypoperistalsis syndrome in humans and mice
Authors: Halim Danny , Wilson Michael P. , Oliver Daniel , Brosens Erwin , Verheij Joke B. G. M. , Han Yu , Nanda Vivek , Lyu Qing , Doukas Michael , Stoop Hans , Brouwer Rutger W. W. , van IJcken Wilfred F. J. , Slivano Orazio J. , Burns Alan J. , Christie Christine K. , de Mesy Bentley Karen L. , Brooks Alice S. , Tibboel Dick , Xu Suowen , Jin Zheng Gen , Djuwantono Tono , Yan Wei , Alves Maria M. , Hofstra Robert M. W. , Miano Joseph M.
Published: March 2017

Significance

Rare recessive monogenic diseases are often found in isolated populations. In one such population, we identified a child carrying a homozygous nonsense mutation in an understudied smooth muscle-restricted gene called
Leiomodin1
(
LMOD1
). Heterozygous parents showed no disease; however, the child died shortly after birth from a rare condition known as megacystis microcolon intestinal hypoperistalsis syndrome. A mouse model with a similar
Lmod1
mutation, engineered with CRISPR-Cas9 genome editing, exhibited the same gastrointestinal and urinary bladder phenotypes as seen in the newborn child. Phenotyping revealed insights into the underlying cause of the disease. Results demonstrate the conserved function of LMOD1 in human and mice and the importance of this protein in the molecular regulation of contractility in visceral smooth muscle cells.
Computational investigation of surface freezing in a molecular model of water
Authors: Haji-Akbari Amir , Debenedetti Pablo G.
Published: March 2017

Significance

Ice nucleation at interfaces plays an important role in atmospheric processes. Because of the insufficient spatiotemporal resolution of the existing experimental techniques, however, it is very difficult to understand how interfaces affect freezing at the molecular level. In particular, whether a vapor–liquid interface enhances or suppresses freezing at its vicinity is still a major unresolved question in contemporary ice physics. We address this question computationally by directly calculating the ice nucleation rate in a freestanding nanofilm of supercooled water modeled using an accurate molecular model and observe seven orders of magnitude enhancement. We observe that freezing initiates away from the air–water interface, in regions of the film favorable to the formation of cubic ice.
Diagnosis of prostate cancer by desorption electrospray ionization mass spectrometric imaging of small metabolites and lipids
Authors: Banerjee Shibdas , Zare Richard N. , Tibshirani Robert J. , Kunder Christian A. , Nolley Rosalie , Fan Richard , Brooks James D. , Sonn Geoffrey A.
Published: March 2017

Significance

Desorption electrospray ionization mass spectrometry imaging (DESI-MSI) is a label-free molecular imaging technique that provides a window into the biochemical processes present in benign and malignant prostate tissue. This is important both in improving the understanding of tissue biology and in achieving rapid cancer diagnosis. We applied DESI-MSI to record lipid, carbohydrate, and most importantly, small metabolite images from 54 normal and malignant prostate tissue specimens. Several Krebs cycle intermediates were present at different concentrations in prostate cancer compared with normal tissue. Statistical calculations identified panels of metabolites that could readily distinguish prostate cancer from normal tissue with nearly 90% accuracy in a validation set. The results also indicated that the ratio of glucose to citrate ion signals could be used to accurately identify prostate cancer.
Noncanonical role of
Arabidopsis
COP1/SPA complex in repressing BIN2-mediated PIF3 phosphorylation and degradation in darkness
Authors: Ling Jun-Jie , Li Jian , Zhu Danmeng , Deng Xing Wang
Published: March 2017

Significance

Initially discovered as a central repressor of the seedling photomorphogenesis in plants, and later characterized in animals, the E3 ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) has been shown to have conserved biochemical activities in eukaryotes. In this study, we show that to coordinately promote skotomorphogenesis, the COP1/ SUPPRESSOR of
phyA-105
(SPA) complex represses the activity of the GSK3-like kinase BRASSINOSTEROID-INSENSITIVE 2 (BIN2) in a nonproteolytic manner to stabilize the key repressor of photomorphogenesis PHYTOCHROME INTERACTING FACTOR 3 (PIF3). The COP1/SPA-BIN2-PIF3 module represents an additional layer of COP1/SPA regulation in
Arabidopsis
and is essential for shaping the plants when grown in the dark.
Small molecule selectively suppresses MYC transcription in cancer cells
Authors: Bouvard Claire , Lim Sang Min , Ludka John , Yazdani Nahid , Woods Ashley K. , Chatterjee Arnab K. , Schultz Peter G. , Zhu Shoutian
Published: March 2017

Significance

Oncogene MYC is up-regulated in up to 75% of all cancers. Suppression of MYC expression or inhibition of MYC function by mutant protein has been shown efficacious in a variety of cancer models. Even though selective MYC-targeting agents have been long sought after, no drugs are available yet. Herein, we demonstrate that a pharmacological agent, stauprimide, selectively suppresses MYC transcription in a variety of cancer cells in vitro and inhibits tumor growth in xenograft mouse models. This study provides not only a proof-of-concept for pharmacologically targeting MYC transcription as an effective strategy for cancer treatment, but also evidence to support further development of stauprimide as an anticancer drug candidate.
Is There Evidence for Biologically Significant Size‐Selective Mortality of Coho Salmon During the First Winter of Marine Residence?
Authors: Beacham Terry D. , Neville Chrys M. , Tucker Strahan , Trudel Marc
Published: March 2017

We examined whether individual Coho Salmon Oncorhynchus kisutch in southern British Columbia had to achieve a sufficient size (“critical size”) by the end of the first marine summer to be able to survive through the ensuing fall and winter. Descriptive statistics of seasonal weight distributions were determined. The expected body weight of an individual sampled in one season was projected to the next season with a growth equation tested on Pink Salmon O. gorbuscha. Projected weight frequencies were then compared with observed weight frequencies in the next season to evaluate whether it was necessary to invoke size‐selective mortality to explain the observed weight frequencies in the next season. Based on estimated growth between July and September, a maximum of 9% of the stock in the Strait of Georgia may have been subjected to size‐selective mortality—far lower than the 63–74% mortality estimated in previous studies. Likewise, there was basically no size‐selective mortality between September and November, yet 48% mortality had been reported previously for this period. We could find no evidence of any critical size that age‐1.0 Coho Salmon juveniles in southern British Columbia had to attain by the end of the first summer or fall of marine rearing to enable them to survive the subsequent winter in the ocean. Thus, there was no support for the hypothesis that Coho Salmon had to achieve a sufficient (critical) size by the end of the first marine summer or fall to be able to survive during the winter of their first year of ocean rearing.

Received May 31, 2016; accepted January 18, 2017 Published online March 15, 2017
Examining theories of cognitive ageing using the false memory paradigm
Authors: Askey Charlotte , Playfoot David
Published: March 2017

Changes in memory performance with advancing age have been well documented, even in the absence of brain injury or dementia. The mechanisms underlying cognitive ageing are still a matter of debate. This article describes a comparison between young (18-25 years old) and older (60+ years) adults using the Deese–Roediger–McDermott false memory paradigm and manipulating the number of words included in the memory lists. Two key theories of cognitive ageing (the Inhibitory Deficit Hypothesis and the Transmission Deficit Hypothesis) predict opposing patterns on this task. Results showed that longer lists increase the likelihood that a lure is retrieved and that older adults are more susceptible to false memories than are younger adults. We argue that these findings are supportive of the Inhibitory Deficit Hypothesis and cannot easily be reconciled with the Transmission Deficit Hypothesis account.
SIApopr: a computational method to simulate evolutionary branching trees for analysis of tumor clonal evolution
Authors: McDonald Thomas O , Michor Franziska
Published: March 2017

SIApopr (Simulating Infinite-Allele populations) is an R package to simulate time-homogeneous and inhomogeneous stochastic branching processes under a very flexible set of assumptions using the speed of C ++. The software simulates clonal evolution with the emergence of driver and passenger mutations under the infinite-allele assumption. The software is an application of the Gillespie Stochastic Simulation Algorithm expanded to a large number of cell types and scenarios, with the intention of allowing users to easily modify existing models or create their own.

Availability and Implementation

SIApopr is available as an R library on Github (https://github.com/olliemcdonald/siapopr).

Supplementary information

Supplementary data are available at Bioinformatics online.