bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption/desorption performance of volatile organic compounds on electrospun nanofibers
Authors: Chu Lanling , Deng Siwei , Zhao Renshan , Zhang Zhao , Li Chen , Kang Xuejun
Published: November 2015

Electrospun nanofibers possess the advantages of the certain selectivity, favorable adsorption/desorption efficiency, short adsorption equilibration time and preferable regeneration and can be a potential adsorbent for VOCs.
Compact wavefunctions from compressed imaginary time evolution
Authors: McClean Jarrod R. , Aspuru-Guzik Alán
Published: November 2015

Compact wavefunctions built through compressed imaginary time evolution enable more efficient modeling of quantum systems.
N
6-Methyladenine hinders RNA- and DNA-directed DNA synthesis: application in human rRNA methylation analysis of clinical specimens
Authors: Wang Shaoru , Wang Jiaqi , Zhang Xiaoe , Fu Boshi , Song Yanyan , Ma Pei , Gu Kai , Zhou Xin , Zhang Xiaolian , Tian Tian , Zhou Xiang
Published: November 2015

Here, we report that m6A significantly hinders DNA- and RNA-directed DNA synthesis, and a quantitative analysis of m6A in RNA or DNA context has been achieved..
Diene hydroaminomethylation via ruthenium-catalyzed C–C bond forming transfer hydrogenation: beyond carbonylation
Authors: Oda Susumu , Franke Jana , Krische Michael J.
Published: November 2015

Ruthenium catalyzed transfer hydrogenation of dienes in the presence of formaldimines delivers products of hydroaminomethylation as single regioisomers.
Metal–organic frameworks for the control and management of air quality: advances and future direction
Authors: Kumar Pawan , Kim Ki-Hyun , Kwon Eilhann E. , Szulejko Jan E.
Published: November 2015

Recently, the potential role of MOFs/PCPs has been recognized in AQM due to their intrinsically tunable chemical structure and multifunctional properties which afford significant enhancements in adsorption capacities, catalytic degradation, and removal of diverse airborne pollutants.
Rational synthesis of metal–organic framework composites, hollow structures and their derived porous mixed metal oxide hollow structures
Authors: Cai Daoping , Liu Bin , Wang Dandan , Wang Lingling , Liu Yuan , Qu Baihua , Duan Xiaochuan , Li Qiuhong , Wang Taihong
Published: November 2015

A chemical transformation method is used to synthesize unique MOF composites, MOF hollow and complex hollow structures. Moreover, porous mixed metal oxide hollow and complex structures are obtained by annealing the MOF hollow and complex hollow structures
Job-sharing cathode design for Li–O2batteries with high energy efficiency enabled by in situ ionic liquid bonding to cover carbon surface defects
Authors: Lou Peili , Li Chilin , Cui Zhonghui , Guo Xiangxin
Published: November 2015

In the job-sharing design of carbon-based cathode for Li–O2batteries, the IL layer is aimed to cover carbon surface defects and suppress side reactions, whereas Ru nanodots are responsible for modifying product microstructure and crystallinity. It enables a high energy efficiency characterized by a substantial charge plateau with extremely small overpotential.
Ammonia sensing for enzymatic urea detection using organic field effect transistors and a semipermeable membrane
Authors: Werkmeister F. X. , Koide T. , Nickel B. A.
Published: November 2015

Organic transistors detect the enzymatic breakdown of ureaviaammonia diffusion into the transistor through a semipermeable parylene-C membrane.
PXR stimulates growth factor-mediated hepatocyte proliferation by cross-talk with the FOXO transcription factor
Authors: Shizu Ryota , Abe Taiki , Benoki Satoshi , Takahashi Miki , Kodama Susumu , Miayata Masaaki , Matsuzawa Atsushi , Yoshinari Kouichi
Published: November 2015

Growth factor-mediated hepatocyte proliferation is crucial in liver regeneration and the recovery of liver function after injury. The nuclear receptor, pregnane X receptor (PXR), is a key transcription factor for the xenobiotic-induced expression of genes associated with various liver functions. Recently, we reported that PXR activation stimulates xenobiotic-induced hepatocyte proliferation. In the present study, we investigated whether PXR activation also stimulates growth factor-mediated hepatocyte proliferation. In G0 phase-synchronized, immortalized mouse hepatocytes, serum or epidermal growth factor treatment increased cell growth and this growth was augmented by the expression of mouse PXR and co-treatment with pregnenolone 16α-carbonitrile (PCN), a PXR ligand. In a liver regeneration model using carbon tetrachloride, PCN treatment enhanced the injury-induced increase in the number of Ki-67-positive nuclei as well as Ccna2 and Ccnb1 mRNA levels in wild-type (WT) but not Pxr-null mice. Chronological analysis of this model demonstrated that PCN treatment shifted the maximum cell proliferation to an earlier time point and increased the number of M-phase cells at those time points. In WT but not Pxr-null mice, PCN treatment reduced hepatic mRNA levels of genes involved in the suppression of G0/G1- and G1/S-phase transition, e.g. Rbl2, Cdkn1a and Cdkn1b. Analysis of the Rbl2 promoter revealed that PXR activation inhibited its Forkhead box O3 (FOXO3)-mediated transcription. Finally, the PXR-mediated enhancement of hepatocyte proliferation was inhibited by the expression of dominant active FOXO3 in vitro. The results of the present study suggest that PXR activation stimulates growth factor-mediated hepatocyte proliferation in mice, at least in part, through inhibiting FOXO3 from accelerating cell-cycle progression.
Involvement of the Hippo pathway in regeneration and fibrogenesis after ischaemic acute kidney injury: YAP is the key effector
Authors: Xu Jing , Li Pei-Xue , Wu Jun , Gao Yi-Jun , Yin Meng-Xin , Lin Ye , Yang Ming , Chen Dong-Ping , Sun Hai-Peng , Liu Zeng-Bo , Gu Xiang-Chen , Huang Hong-Ling , Fu Li-Li , Hu Hui-Min , He Liang-Liang , Wu Wen-Qing , Fei Zhao-Liang , Ji Hong-Bin , Zhang Lei , Mei Chang-Lin
Published: November 2015

Renal tubule cells can recover after they undergo AKI (acute kidney injury). An incomplete repair of renal tubules can result in progressive fibrotic CKD (chronic kidney disease). Studies have revealed the relationship between tubular epithelial cells and kidney fibrogenesis. However, the underlying mechanism remains unclear. Hippo pathway components were evaluated in complete/incomplete repair of I/R (ischaemia/reperfusion) AKI rat models, HK-2 cells and AKI human renal biopsy samples. We found that the expression levels of the Hippo pathway components changed dynamically during kidney regeneration and fibrogenesis in rat models of I/R-induced AKI and human renal biopsy samples. The transcription cofactor YAP (Yes-associated protein) might be a key effector of renal regeneration and fibrogenesis. Our results showed further that YAP might elicit both beneficial and detrimental effects on I/R AKI. After I/R injury occurred, YAP could promote the repair of the injured epithelia. The constant YAP increase and activation might be related to interstitial fibrosis and abnormal renal tubule differentiation. These results indicate that the proper modulation of the Hippo pathway, specifically the transcription cofactor YAP, during repair might be a potent therapeutic target in AKI–CKD transition after I/R injury.
Low‐noise tunable filter design by means of active components
Authors: Pantoli L. , Stornelli V. , Leuzzi G.
Published: November 2015

A low‐noise tunable filter with high dynamic range and minimum power consumption is presented and addressed with circuit details. It is based on an active solution simulating an inductive behaviour that allows improving the filter quality factor without affecting the noise performance. The low‐order bandpass filter is realised with minimum number of components and it is suitable to be integrated in integrated circuit or used in hybrid transceiver and modern reconfigurable radio systems. A prototype board with discrete components has been fabricated and tested with good results.
Harmonic reference currents balancing method for delta‐connected static synchronous compensator
Authors: Wang Baoan , Shang Jiao , Dai NingYi , Chen Hao
Published: November 2015

A static synchronous compensator (STATCOM) with a delta configuration is able to compensate for reactive currents, unbalanced currents and harmonic currents in a three‐phase three‐wire system. A method is proposed for balancing the harmonic currents among three phases of the STATCOM without affecting line harmonic currents injecting into the grid. The rating of the STATCOM can be lower because the maximum phase current is reduced. Simulation and experimental results are provided to show the effectiveness of the proposed method.
pH ISFET sensor with PVTA compensation
Authors: Carrillo‐Martínez L.A. , Espinosa Flores‐Verdad G. , Pérez B.M. , Molina Reyes J.
Published: November 2015

Sensory system performance and variability depend on the compensation degree against fabrication process, voltage, temperature and ageing (PVTA) variations. A pH ion sensitive field‐effect transistor sensor with PVTA compensation is presented; stages for calibration and sensitivity adjustment were also included. To validate its performance, the proposed sensor was compared with a non‐compensated sensor; the results showed that PVTA variations were reduced by 81.50% for fabrication process and ageing, 87.91% for voltage and 80.30% for temperature. The maximum resolution achieved was 833.33 mV/pH.
Video stabilisation based on modelling of motion imaging
Authors: Yu Jialin , Xiang Ke , Wang Xuanyin , Cao Songxiao , Zhang Yang
Published: November 2015

This study proposes a novel digital video stabilisation scheme based on modelling of motion imaging (MI). The modelling of MI eliminates the speed motion as a result of a moving car, which is ignored in other models such as rotation + translation model, and estimates movement parameters of the background in video sequences captured from cameras mounted on moving cars. The authors first analyse the MI to understand the principle of the effects of car motion on MI, and select the matching method according to the proposed model. Then, they employ symmetric points to remove the speed motion. Finally, unwanted motion vector is stimulated by employing adaptive step‐length filter, and the boundary compensating approach is employed to suppress the image jitter effectively. Their major contribution is the elimination of the effect of carrier's speed in motion estimation. Other contributions include new robust block matching approach and adaptive‐step selection for motion filtering. They conduct experiments on real videos and artificial data. Experiments on real videos show that the proposed model can remove the effect of car motion, whereas the experiments on artificial data are conducted for theoretical analysis.
Battery optimal scheduling based on energy balance in wireless sensor networks
Authors: Jin Rencheng , Che Zhiping , Wang Zhen , Zhu Ming , Wang Liding
Published: November 2015

In wireless sensor networks, sensors are usually equipped with limited lifetime batteries. To face the short lifetime, some sensor nodes have the option to connect an extra battery, or to use smart battery‐packs with multiple cells. In these cases, a major technique to save the energy is to schedule the batteries or battery cells through the properties of the batteries. This study presents a scheduling algorithm to decide which batteries have to work based on the remaining energy. Hence, the energy consumption model of node based on ZigBee protocol was proposed. The parameters, including working current, working voltage, time duration of data sending and receiving, and so on are used to establish energy consumption model of node. Experiment based on JN5148 shows that the energy consumption model is feasible. Using the kinetic battery model and configuring relevant parameters can accurately express battery's energy consumption curve. On the basis of the above work, MATLAB simulation results show that the proposed battery scheduling strategy is superior to best‐of‐two scheduling.
Correlation‐aware cross‐layer design for network management of wireless sensor networks
Authors: Das Sankar Narayan , Misra Sudip
Published: November 2015

The observations of the nodes of a wireless sensor network are spatiotemporally correlated. Sensor nodes can exploit the correlation for enhancing network efficiency. However, an energy‐efficient collaboration is required for better network management. For saving energy, sensor nodes schedule between Active and Sleep states. Nodes extract information from medium access control layer, and use that information along with the correlation of observations as a means of energy‐efficient collaboration and proper scheduling of their Active and Sleep states. Furthermore, sensor nodes use non‐deterministic reinforcement learning‐based approach for reducing energy consumption and end‐to‐end delay by regulating the duration of their Sleep states. Extensive simulations have shown that the proposed cross‐layer approach outperforms existing benchmark schemes in terms of end‐to‐end delay, data accuracy and energy efficiency.
Communication: Kohn-Sham theory for excited states of Coulomb systems
Authors: Ayers P. W. , Levy M. , Nagy Á.
Published: November 2015

For obtaining individual excited-state energies and densities of Coulomb electronic systems, by means of an energy stationary principle, it was shown previously that there exists a universal functional of the density, FCoul[ϱ], for the kinetic plus electron-electron repulsion part of the total energy. Here, we make knowledge of the existence of FCoul[ϱ] practical for calculation by identifying TsCoul[ϱ], the non-interacting kinetic energy component of FCoul[ϱ], and by showing that TsCoul[ϱ] may be computed exactly by means of orbitals that are obtained through a set of single-particle Kohn-Sham equations. Constraints for obtaining accurate approximations to the remaining unknown component of FCoul[ϱ] are presented.
Scaling of the dynamics of flexible Lennard-Jones chains: Effects of harmonic bonds
Authors: Veldhorst Arno A. , Dyre Jeppe C. , Schrøder Thomas B.
Published: November 2015

The previous paper [A. A. Veldhorst et al., J. Chem. Phys. 141, 054904 (2014)] demonstrated that the isomorph theory explains the scaling properties of a liquid of flexible chains consisting of ten Lennard-Jones particles connected by rigid bonds. We here investigate the same model with harmonic bonds. The introduction of harmonic bonds almost completely destroys the correlations in the equilibrium fluctuations of the potential energy and the virial. According to the isomorph theory, if these correlations are strong a system has isomorphs, curves in the phase diagram along which structure, dynamics, and the excess entropy are invariant. The Lennard-Jones chain liquid with harmonic bonds does have curves in the phase diagram along which the structure and dynamics are invariant. The excess entropy is not invariant on these curves, which we refer to as “pseudoisomorphs.” In particular, this means that Rosenfeld’s excess-entropy scaling (the dynamics being a function of excess entropy only) does not apply for the Lennard-Jones chain with harmonic bonds.
High current density ion beam obtained by a transition to a highly focused state in extremely low-energy region
Authors: Hirano Y. , Kiyama S. , Fujiwara Y. , Koguchi H. , Sakakita H.
Published: November 2015

A high current density (≈3 mA/cm2) hydrogen ion beam source operating in an extremely low-energy region (Eib ≈ 150–200 eV) has been realized by using a transition to a highly focused state, where the beam is extracted from the ion source chamber through three concave electrodes with nominal focal lengths of ≈350 mm. The transition occurs when the beam energy exceeds a threshold value between 145 and 170 eV. Low-level hysteresis is observed in the transition when Eib is being reduced. The radial profiles of the ion beam current density and the low temperature ion current density can be obtained separately using a Faraday cup with a grid in front. The measured profiles confirm that more than a half of the extracted beam ions reaches the target plate with a good focusing profile with a full width at half maximum of ≈3 cm. Estimation of the particle balances in beam ions, the slow ions, and the electrons indicates the possibility that the secondary electron emission from the target plate and electron impact ionization of hydrogen may play roles as particle sources in this extremely low-energy beam after the compensation of beam ion space charge.
Transferability and accuracy by combining dispersionless density functional and incremental post-Hartree-Fock theories: Noble gases adsorption on coronene/graphene/graphite surfaces
Authors: de Lara-Castells María Pilar , Bartolomei Massimiliano , Mitrushchenkov Alexander O. , Stoll Hermann
Published: November 2015

The accuracy and transferability of the electronic structure approach combining dispersionless density functional theory (DFT) [K. Pernal et al., Phys. Rev. Lett. 103, 263201 (2009)] with the method of increments [H. Stoll, J. Chem. Phys. 97, 8449 (1992)], are validated for the interaction between the noble-gas Ne, Ar, Kr, and Xe atoms and coronene/graphene/graphite surfaces. This approach uses the method of increments for surface cluster models to extract intermonomer dispersion-like (2- and 3-body) correlation terms at coupled cluster singles and doubles and perturbative triples level, while periodic dispersionless density functionals calculations are performed to estimate the sum of Hartree-Fock and intramonomer correlation contributions. Dispersion energy contributions are also obtained using DFT-based symmetry-adapted perturbation theory [SAPT(DFT)]. An analysis of the structure of the X/surface (X = Ne, Ar, Kr, and Xe) interaction energies shows the excellent transferability properties of the leading intermonomer correlation contributions across the sequence of noble-gas atoms, which are also discussed using the Drude oscillator model. We further compare these results with van der Waals-(vdW)-corrected DFT-based approaches. As a test of accuracy, the energies of the low-lying nuclear bound states supported by the laterally averaged X/graphite potentials (X = 3He, 4He, Ne, Ar, Kr, and Xe) are calculated and compared with the best estimations from experimental measurements and an atom-bond potential model using the ab initio-assisted fine-tuning of semiempirical parameters. The bound-state energies determined differ by less than 6–7 meV (6%) from the atom-bond potential model. The crucial importance of including incremental 3-body dispersion-type terms is clearly demonstrated, showing that the SAPT(DFT) approach effectively account for these terms. With the deviations from the best experimental-based estimations smaller than 2.3 meV (1.9%), the accuracy of the combined DFT and post-HF incremental scheme is established for all the noble-gas atoms. With relative deviations smaller than 4% and 11%, good agreement is also achieved by applying the vdW-corrected DFT treatments PBE-D3 and vdW-DF2 for noble-gas atoms heavier than neon.
Graphene phonon softening and splitting by directional straining
Authors: Yang X. X. , Wang Y. , Li J. W. , Liao W. H. , Liu Y. H. , Sun Chang Q.
Published: November 2015

Strain-induced graphene phonon softening and phonon band splitting are indeed fascinating, which were attributed to the phonon double resonant scattering without intrinsic involvement of C-C bond relaxation. Here, we show that the lengthening and weakening of the C-C bond softens the phonon and that the mismatching between the uniaxial strain and the C3v bond geometry splits the band. In addition to the force constant of 11.8 N/m for a C-C bond in graphene, consistency between theory and measurements derives that if the strain is along a bond, maximal band splitting happens; if the strain is perpendicular, no band splitting occurs.
Experimental investigation of non-linear wave to plasma interaction in a quasi-flat magnetostatic field
Authors: Castro G. , Mascali D. , Agnello R. , Celona L. , Leonardi O. , Neri L. , Nicolosi D. , Torrisi G. , Gammino S.
Published: November 2015

A characterization of wave-to-plasma interaction in a quasi-flat magnetostatic field at 3.75 GHz has been carried out by using a small-wire movable RF antenna, connected to a spectrum analyzer. The coupling between electromagnetic and electrostatic waves leads to a characteristic spectral emission in low frequency range and around the pumping wave frequency. The most relevant results consist in the broadening of the pumping wave spectrum above critical RF power thresholds and in the generation of sidebands of the pumping frequency, with corresponding components in low frequency domain. The non-linearities are accompanied by the generation of overdense plasmas and intense fluxes of X-rays.
A near infra-red video system as a protective diagnostic for electron cyclotron resonance heating operation in the Wendelstein 7-X stellarator
Authors: Preynas M. , Laqua H. P. , Marsen S. , Reintrog A. , Corre Y. , Moncada V. , Travere J.-M.
Published: November 2015

The Wendelstein 7-X stellarator is a large nuclear fusion device based at Max-Planck-Institut für Plasmaphysik in Greifswald in Germany. The main plasma heating system for steady state operation in W7-X is electron cyclotron resonance heating (ECRH). During operation, part of plama facing components will be directly heated by the non-absorbed power of 1 MW rf beams of ECRH. In order to avoid damages of such components made of graphite tiles during the first operational phase, a near infra-red video system has been developed as a protective diagnostic for safe and secure ECRH operation. Both the mechanical design housing the camera and the optical system are very flexible and respect the requirements of steady state operation. The full system including data acquisition and control system has been successfully tested in the vacuum vessel, including on-line visualization and data storage of the four cameras equipping the ECRH equatorial launchers of W7-X.
Computational modelling of the complex dynamics of chemically blown polyurethane foam
Authors: Ireka I. E. , Niedziela D. , Schäfer K. , Tröltzsch J. , Steiner K. , Helbig F. , Chinyoka T. , Kroll L.
Published: November 2015

This study presents computational analysis of the complex dynamics observed in chemically blown polyurethane foams during reaction injection molding process. The mathematical formulation introduces an experimentally motivated non-divergence free setup for the continuity equations which reflects the self expanding behaviour observed in the physical system. The foam growth phenomena which is normally initiated by adequate pre-mixing of necessary reactant polymers, leading to an exothermic polymerization reaction, bubble nucleation, and gas formation, is captured numerically. We assume the dependence of material viscosity on the degree of cure/polymerization, gas volume fraction, and temperature as well as non-dependence of mixture density on pressure. The set of unsteady nonlinear coupled partial differential equations describing the dynamics of the system are solved numerically for state variables using finite volume techniques such that the front of the flow is tracked with high resolution interface capturing schemes. Graphical representation of the foam volume fraction, evolution of foam heights, and temperature distributions is presented. Results from our simulations are validated with experimental data. These results show good quantitative agreement with observations from experiments.
Electrical and structural properties of ZnO synthesized via infiltration of lithographically defined polymer templates
Authors: Nam Chang-Yong , Stein Aaron , Kisslinger Kim , Black Charles T.
Published: November 2015

We investigate the electrical and structural properties of infiltration-synthesized ZnO. In-plane ZnO nanowire arrays with prescribed positional registrations are generated by infiltrating diethlyzinc and water vapor into lithographically defined SU-8 polymer templates and removing organic matrix by oxygen plasma ashing. Transmission electron microscopy reveals that homogeneously amorphous as-infiltrated polymer templates transform into highly nanocrystalline ZnO upon removal of organic matrix. Field-effect transistor device measurements show that the synthesized ZnO after thermal annealing displays a typical n-type behavior, ∼1019 cm−3 carrier density, and ∼0.1 cm2 V−1 s−1 electron mobility, reflecting highly nanocrystalline internal structure. The results demonstrate the potential application of infiltration synthesis in fabricating metal oxide electronic devices.
Temperature and compression effects on electron heat capacity and electron-phonon coupling in aluminum and beryllium: Insights from ab initio simulations
Authors: Li Zi , Wang Cong , Kang Wei , Li Chuanying , Zhang Ping
Published: November 2015

Ultrafast laser experiments on metals usually induce a high electron temperature and a low ion temperature and, thus, an energy relaxation process. The electron heat capacity and electron-phonon coupling factor are crucial thermal quantities to describe this process. We perform ab initio theoretical studies to determine these thermal quantities and their dependence on density and electron temperature for the metals aluminum and beryllium. The heat capacity shows an approximately linear dependence on the temperature, similar to free electron gas, and the compression only slightly affects the capacity. The electron-phonon coupling factor increases with both temperature and density, and the change observed for beryllium is more obvious than that for aluminum. The connections between thermal quantities and electronic/atomic structures are discussed in detail, and the different behaviors of aluminum and beryllium are well explained.
Dynamic metamaterial aperture for microwave imaging
Authors: Sleasman Timothy , F. Imani Mohammadreza , Gollub Jonah N. , Smith David R.
Published: November 2015

We present a dynamic metamaterial aperture for use in computational imaging schemes at microwave frequencies. The aperture consists of an array of complementary, resonant metamaterial elements patterned into the upper conductor of a microstrip line. Each metamaterial element contains two diodes connected to an external control circuit such that the resonance of the metamaterial element can be damped by application of a bias voltage. Through applying different voltages to the control circuit, select subsets of the elements can be switched on to create unique radiation patterns that illuminate the scene. Spatial information of an imaging domain can thus be encoded onto this set of radiation patterns, or measurements, which can be processed to reconstruct the targets in the scene using compressive sensing algorithms. We discuss the design and operation of a metamaterial imaging system and demonstrate reconstructed images with a 10:1 compression ratio. Dynamic metamaterial apertures can potentially be of benefit in microwave or millimeter wave systems such as those used in security screening and through-wall imaging. In addition, feature-specific or adaptive imaging can be facilitated through the use of the dynamic aperture.
A simplified method for generating periodic nanostructures by interference lithography without the use of an anti-reflection coating
Authors: Kapon Omree , Muallem Merav , Palatnik Alex , Aviv Hagit , Tischler Yaakov. R.
Published: November 2015

Interference lithography has proven to be a useful technique for generating periodic sub-diffraction limited nanostructures. Interference lithography can be implemented by exposing a photoresist polymer to laser light using a two-beam arrangement or more simply a one beam configuration based on a Lloyd's Mirror Interferometer. For typical photoresist layers, an anti-reflection coating must be deposited on the substrate to prevent adverse reflections from cancelling the holographic pattern of the interfering beams. For silicon substrates, such coatings are typically multilayered and complex in composition. By thinning the photoresist layer to a thickness well below the quarter wavelength of the exposing beam, we demonstrate that interference gratings can be generated without an anti-reflection coating on the substrate. We used ammonium dichromate doped polyvinyl alcohol as the positive photoresist because it provides excellent pinhole free layers down to thicknesses of 40 nm, and can be cross-linked by a low-cost single mode 457 nm laser, and can be etched in water. Gratings with a period of 320 nm and depth of 4 nm were realized, as well as a variety of morphologies depending on the photoresist thickness. This simplified interference lithography technique promises to be useful for generating periodic nanostructures with high fidelity and minimal substrate treatments.
Detrimental effect of interfacial Dzyaloshinskii-Moriya interaction on perpendicular spin-transfer-torque magnetic random access memory
Authors: Jang Peong-Hwa , Song Kyungmi , Lee Seung-Jae , Lee Seo-Won , Lee Kyung-Jin
Published: November 2015

Interfacial Dzyaloshinskii-Moriya interaction in ferromagnet/heavy metal bilayers is recently of considerable interest as it offers an efficient control of domain walls and the stabilization of magnetic skyrmions. However, its effect on the performance of perpendicular spin transfer torque memory has not been explored yet. We show based on numerical studies that the interfacial Dzyaloshinskii-Moriya interaction decreases the thermal energy barrier while increases the switching current. As high thermal energy barrier as well as low switching current is required for the commercialization of spin torque memory, our results suggest that the interfacial Dzyaloshinskii-Moriya interaction should be minimized for spin torque memory applications.
Tunable polaritonic molecules in an open microcavity system
Authors: Dufferwiel S. , Li Feng , Trichet A. A. P. , Giriunas L. , Walker P. M. , Farrer I. , Ritchie D. A. , Smith J. M. , Skolnick M. S. , Krizhanovskii D. N.
Published: November 2015

We experimentally demonstrate tunable coupled cavities based upon open access zero-dimensional hemispherical microcavities. The modes of the photonic molecules are strongly coupled with quantum well excitons forming a system of tunable polaritonic molecules. The cavity-cavity coupling strength, which is determined by the degree of modal overlap, is controlled through the fabricated centre-to-centre distance and tuned in-situ through manipulation of both the exciton-photon and cavity-cavity detunings by using nanopositioners to vary the mirror separation and angle between them. We demonstrate micron sized confinement combined with high photonic Q-factors of 31 000 and lower polariton linewidths of 150 μeV at resonance along with cavity-cavity coupling strengths between 2.5 meV and 60 μeV for the ground cavity state.
Thermal conductivity in nanocrystalline-SiC/C superlattices
Authors: Habermehl S. , Serrano J. R.
Published: November 2015

The formation of thin film superlattices consisting of alternating layers of nitrogen-doped SiC (SiC:N) and C is reported. Periodically terminating the SiC:N surface with a graphitic C boundary layer and controlling the SiC:N/C thickness ratio yield nanocrystalline SiC grains ranging in size from 365 to 23 nm. Frequency domain thermo-reflectance is employed to determine the thermal conductivity, which is found to vary from 35.5 W m−1 K−1 for monolithic undoped α-SiC films to 1.6 W m−1 K−1 for a SiC:N/C superlattice with a 47 nm period and a SiC:N/C thickness ratio of 11. A series conductance model is employed to explain the dependence of the thermal conductivity on the superlattice structure. The results indicate that the thermal conductivity is more dependent on the SiC:N/C thickness ratio than the SiC:N grain size, indicative of strong boundary layer phonon scattering.
Spectral linewidth of spin-current nano-oscillators driven by nonlocal spin injection
Authors: Demidov V. E. , Urazhdin S. , Divinskiy B. , Rinkevich A. B. , Demokritov S. O.
Published: November 2015

We study experimentally the auto-oscillation characteristics of magnetic nano-oscillators driven by pure spin currents generated by nonlocal spin injection. By combining micro-focus Brillouin light scattering spectroscopy with electronic microwave spectroscopy, we are able to simultaneously perform both the spatial and the high-resolution spectral analyses of auto-oscillations induced by spin current. We find that the devices exhibit a highly coherent dynamics with the spectral linewidth of a few megahertz at room temperature. This narrow linewidth can be achieved over a wide range of operational frequencies, demonstrating a significant potential of nonlocal oscillators for applications.
The magnetization behavior and open recoil loops of hot-deformed Nd-Fe-B magnets infiltrated by low melting point PrNd-Cu alloys
Authors: Tang Xu , Chen Renjie , Yin Wenzong , Jin Chaoxiang , Lee Don , Yan Aru
Published: November 2015

Ultrahigh coercivity of hot-deformed Nd-Fe-B magnets was obtained by low melting point PrNd-Cu alloys diffusion process. The coercivity was largely increased from 15.35 to 27.30 kOe. Magnetic isolation by nonmagnetic phases should be the primary explanation for the enhancement of coercivity. High susceptibility of the recoil loops at low field indicated that magnetic domain wall motion within grains was easy, while a near-zero reversible susceptibility of recoil loops implied that domain wall strong pinning at grain boundaries was dominant at higher field in initial magnetization process. Open recoil loops were also obtained in the infiltrated magnets and disappeared when the external field exceeded about 16 kOe lightly higher than the coercivity of the magnet without diffusion process. The inhomogeneous distribution of infiltrated phases that led to the grains aggregation and single grains with softer and harder magnetic characteristics, respectively, may be the primary reason for the phenomenon. The stray field produced by isolated single grains plays a critical role in the magnetization behavior. A phenomenological model for the magnetization reversal was built to interpret the open recoil loops in a recoil loop process.
Carrier-envelope phase control of a 10 Hz, 25 TW laser for high-flux extreme ultraviolet quasi-continuum generation
Authors: Cunningham E. , Wu Y. , Chang Zenghu
Published: November 2015

A scheme for stabilizing the carrier-envelope phase (CEP) of low-repetition rate lasers was demonstrated using a 350 mJ, 14 fs Ti:Sapphire laser operating at 10 Hz. The influence of the CEP on the generation of a quasi-continuum in the extreme ultraviolet was observed.
Global impacts of energy demand on the freshwater resources of nations
Authors: Holland Robert Alan , Scott Kate A. , Flörke Martina , Brown Gareth , Ewers Robert M. , Farmer Elizabeth , Kapos Valerie , Muggeridge Ann , Scharlemann Jörn P. W. , Taylor Gail , Barrett John , Eigenbrod Felix
Published: November 2015

Significance

Understanding the role of international trade in driving pressures on freshwater resources is key to meeting challenges at the water–energy nexus. A coupled trade and hydrological model is used to examine pressures on freshwater resources associated with energy production across the global economy. While the electric and gas sectors induce freshwater consumption predominantly within countries where demand originates (91% and 81%, respectively), the petroleum sector exhibits a high international footprint (56%). Critical geographic areas and economic sectors are identified, providing focus for resource-management actions to ensure energy and freshwater security. Our analysis demonstrates the importance of broadening the discourse on energy policy to address issues including freshwater scarcity, the role of international trade, and wider environmental and societal considerations.
Rad51 recombinase prevents Mre11 nuclease-dependent degradation and excessive PrimPol-mediated elongation of nascent DNA after UV irradiation
Authors: Vallerga María Belén , Mansilla Sabrina F. , Federico María Belén , Bertolin Agustina P. , Gottifredi Vanesa
Published: November 2015

Significance

Pathways that promote DNA replication across replication barriers are central for cell survival. Herein, we report that in UV-irradiated cells lacking the Rad51 recombinase (Rad51), the DNA replication choreography is profoundly altered. We detected excessive degradation of nascent DNA followed by dysregulated elongation of DNA across UV barriers. PrimPol, a DNA polymerase with primase activity, promoted excessive elongation of nascent DNA, thus suggesting the accumulation of discontinuous replication tracks in Rad51-depleted cells. The altered DNA replication choreography in Rad51-knockdown samples resulted in the accumulation of replication stress markers and cell death. Hence, Rad51 promotes multiple, biologically relevant events at ongoing forks that encounter UV-damaged replication templates.
Feeding the brain and nurturing the mind: Linking nutrition and the gut microbiota to brain development
Authors: Goyal Manu S. , Venkatesh Siddarth , Milbrandt Jeffrey , Gordon Jeffrey I. , Raichle Marcus E.
Published: November 2015

The human gut contains a microbial community composed of tens of trillions of organisms that normally assemble during the first 2–3 y of postnatal life. We propose that brain development needs to be viewed in the context of the developmental biology of this “microbial organ” and its capacity to metabolize the various diets we consume. We hypothesize that the persistent cognitive abnormalities seen in children with undernutrition are related in part to their persistent gut microbiota immaturity and that specific regions of the brain that normally exhibit persistent juvenile (neotenous) patterns of gene expression, including those critically involved in various higher cognitive functions such as the brain’s default mode network, may be particularly vulnerable to the effects of microbiota immaturity in undernourished children. Furthermore, we postulate that understanding the interrelationships between microbiota and brain metabolism in childhood undernutrition could provide insights about responses to injury seen in adults. We discuss approaches that can be used to test these hypotheses, their ramifications for optimizing nutritional recommendations that promote healthy brain development and function, and the potential societal implications of this area of investigation.
Genomic insights into the evolutionary origin of Myxozoa within Cnidaria
Authors: Chang E. Sally , Neuhof Moran , Rubinstein Nimrod D. , Diamant Arik , Philippe Hervé , Huchon Dorothée , Cartwright Paulyn
Published: November 2015

Significance

Myxozoans are a diverse group of microscopic parasites that infect invertebrate and vertebrate hosts. The assertion that myxozoans are highly reduced cnidarians is supported by the presence of polar capsules, which resemble cnidarian stinging structures called “nematocysts.” Our study characterizes the genomes and transcriptomes of two distantly related myxozoan species,
Kudoa iwatai
and
Myxobolus cerebralis
, and another cnidarian parasite,
Polypodium hydriforme
. Phylogenomic analyses that use a broad sampling of myxozoan taxa confirm the position of myxozoans within Cnidaria with
P. hydriforme
as the sister taxon to Myxozoa. Analyses of myxozoan genomes indicate that the transition to the highly reduced body plan was accompanied by massive reduction in genome size, including depletion of genes considered hallmarks of animal multicellularity.
Dissecting neural pathways for forgetting in
Drosophila
olfactory aversive memory
Authors: Shuai Yichun , Hirokawa Areekul , Ai Yulian , Zhang Min , Li Wanhe , Zhong Yi
Published: November 2015

Significance

Forgetting is an important aspect of memory and cognition, yet its underlying mechanisms remain poorly understood. In this work, we describe neural circuits involved in the forgetting of olfactory associative memory after odor–shock pairing in
Drosophila
. Our work establishes an anatomically well-defined example where forgetting is regulated by multiple neural pathways that impinge upon a memory center. We also show that forgetting over time and the acute forgetting of conflicting memory during reversal learning rely on separable neural circuits. Overall, these findings support the emerging view that forgetting is a biologically regulated process of the brain, and also open the door to studying the diverse circuit mechanisms of forgetting in different contexts.
Murine germinal center B cells require functional Fms-like tyrosine kinase 3 signaling for IgG1 class-switch recombination
Authors: Svensson Mattias N. D. , Andersson Karin M. E. , Wasén Caroline , Erlandsson Malin C. , Nurkkala-Karlsson Merja , Jonsson Ing-Marie , Brisslert Mikael , Bemark Mats , Bokarewa Maria I.
Published: November 2015

Significance

The protein kinase fms-like tyrosine kinase 3 receptor (Flt3) has an important role during early B-cell development. Recent reports have shown that Flt3 is reexpressed on peripheral B cells during activation, however the function for Flt3 during B-cell activation is poorly understood. The present study describes a role for Flt3 during B-cell activation and antibody production. We show that Flt3 is reexpressed on activated germinal center B cells and that lack of functional Flt3 signaling in peripheral B cells results in a specific deficiency in production of the antibody subclass IgG1. Mechanistic studies indicate that Flt3 synergizes with the IL-4 receptor to promote proper activation of Stat6 and class switch to IgG1. This study provides evidence for a previously unknown function for Flt3 during peripheral B-cell activation.
Stress dynamically regulates behavior and glutamatergic gene expression in hippocampus by opening a window of epigenetic plasticity
Authors: Nasca Carla , Zelli Danielle , Bigio Benedetta , Piccinin Sonia , Scaccianoce Sergio , Nisticò Robert , McEwen Bruce S.
Published: November 2015

Significance

Chronic stress alters the hippocampal responses to familiar and novel stressors, behaviorally, physiologically, and epigenetically. In the aftermath of chronic stress in WT mice and in mice with a BDNF loss-of-function allele without any applied stress, there is a window of plasticity that allows familiar and novel experiences to alter anxiety- and depressive-like behaviors, reflected also in electrophysiological changes in the dentate gyrus (DG) in vitro. A consistent biomarker of mood-related behaviors in DG is reduced type 2 metabotropic glutamate (mGlu2), which regulates the release of glutamate. Within this window, familiar stress rapidly and epigenetically up-regulates mGlu2 by a P300-driven histone H3 lysine 27 acetylation and improves mood behaviors. This transient epigenetic plasticity may be useful for treatment of stress-related disorders where dysregulaton of glutamate is involved.
Enhancing potency of siRNA targeting fusion genes by optimization outside of target sequence
Authors: Gavrilov Kseniya , Seo Young-Eun , Tietjen Gregory T. , Cui Jiajia , Cheng Christopher J. , Saltzman W. Mark
Published: November 2015

Significance

Potency is a key parameter in development of siRNAs for clinical use. However, current design and optimization approaches are concentrated on determining best target sequences within the entire mRNA sequence of interest. This methodology falls short when the available region of the target mRNA becomes restricted, as when targeting the junction site of a fusion oncogene. Here we demonstrate alternative optimization strategies for further improving silencing performance when the targetable region of the mRNA is confined. We apply this approach for siRNA against fusion genes BCR-ABL and TMPRSS2-ERG. We further demonstrate the importance of concurrent development of siRNA design and delivery strategies for more effective siRNA therapeutics and draw attention to the implications of target protein half-life and nonspecific vehicle toxicity.
Responsiveness of G protein-coupled odorant receptors is partially attributed to the activation mechanism
Authors: Yu Yiqun , de March Claire A. , Ni Mengjue J. , Adipietro Kaylin A. , Golebiowski Jérôme , Matsunami Hiroaki , Ma Minghong
Published: November 2015

Significance

Mammalian odorant receptors (ORs) comprise the largest family of G protein-coupled receptors, which are frequent drug targets. While many ORs respond specifically to select odorants, recent studies have identified a small number of ORs that respond to a large set of diverse odorants. Up to date, little is known about the molecular and structural features that shape the OR response properties. Our study reveals that broadly responsive ORs show elevated basal activity, suggesting a lower activation barrier. Surprisingly, a single amino acid mutation is sufficient to confer high basal activity and broad responsiveness to an OR, which originally shows weak responses to few odorants.
Architecture of the human XPC DNA repair and stem cell coactivator complex
Authors: Zhang Elisa T. , He Yuan , Grob Patricia , Fong Yick W. , Nogales Eva , Tjian Robert
Published: November 2015

Significance

Embryonic or pluripotent stem cells are unique in their ability to self-renew in culture and to generate all lineages of an adult organism, making them valuable tools for modeling early developmental processes and for developing regenerative medicine technologies. An important factor in controlling the expression of pluripotency genes is the Xeroderma pigmentosum complementation group C (XPC) DNA repair complex. This study presents, to our knowledge, the first complete structures of different XPC complexes by electron microscopy to establish an important framework for a molecular understanding of XPC’s two primary functions. In conjunction with our biochemical findings, we synthesize a model of how XPC performs both its evolutionarily conserved DNA repair function and its evolutionarily nonconserved transcription function.
Imbalanced signal transduction in regulatory T cells expressing the transcription factor FoxP3
Authors: Yan Dapeng , Farache Julia , Mingueneau Michael , Mathis Diane , Benoist Christophe
Published: November 2015

Significance

The homeostasis of FoxP3
+
Treg cells, essential controllers of immune and autoimmune responses, integrates inputs from the antigen-specific T-cell receptor (TCR) and from trophic cytokines or chemotactic cues. Expanding upon previous indications that Treg cells might be hyporesponsive, we find that TCR triggering induces dampened responses along all tested pathways in Treg compared with conventional CD4
+
T cells, whereas their responses to IFN-I, IL6, or IL2 were equal or stronger. This imbalance indicates that Treg cells are less sensitive to direct recognition of novel antigens, for instance of an infectious nature, and more to cytokine-based cues or intercellular communication.
Reversed-phase liquid chromatographic analysis of hydrophobic interaction between proanthocyanidins and a C8-alkyl compound in aqueous solution
Authors: Yanagida Akio , Takeshige Shinya , Shibusawa Yoichi
Published: November 2015

Structural and physicochemical properties of oligomeric flavan-3-ols (proanthocyanidins) in aqueous solution were investigated by spectrometric and reversed-phase (RP) HPLC analyses. Circular dichroism and fluorescence spectra of (–)-epicatechin (EC) oligomers linked through C-4 to C-8 interflavan bonds showed that EC oligomers larger than dimers formed a stable secondary structure in water. These EC oligomers are water-soluble hydrophilic compounds, whereas the oligomers were strongly retained by a C8-alkyl stationary phase under conventional RP-HPLC conditions. In a further C8-HPLC study, the hydrophobic interaction between EC oligomers and 1-octanesulfonic acid sodium salt (OSA Na) added to the mobile phase was quantitatively evaluated based on the relationship between the logarithm of the retention factor of the solute and the OSA Na concentration in the mobile phase. The strength values of the hydrophobic interaction of EC oligomers larger than dimers were the highest of 22 tested polyphenolic standards.