bluuebunny/crossref_metadata_2025 huggingface dataset:
Amino Acid Salt Catalyzed Asymmetric Addition Reaction of Acetylacetone to Maleimides and 2-(2-Oxoindolin-3-ylidene)malononitriles
Authors: Wu Haiyan , Liu Hongxin , Li Juan , Li Xinhua , Xiao Hong-Ping , Jiang Jun
Published: May 2019

The exploration of catalytic potential of natural amino acid salt in activation of 1,3-dicarbonyls was carried out, in which maleimides and 2-(2-oxoindolin-3-ylidene)malononitriles were found to be good electrophiles and afforded the desired products with excellent yield and moderate optical purity. Control experiments showed that the secondary amino group of barium (S)-prolinate is critical to the catalytic activity as well as enantiocontrol, thus revealed an enamine activation mechanism is possible in the present methodology.
Nickel-Catalyzed β-Carboxylation of Ynamides with Carbon Dioxide
Authors: Doi Ryohei , Okano Taichi , Abdullah Iman , Sato Yoshihiro
Published: May 2019

A nickel-catalyzed β-selective hydrocarboxylation of ynamides to give protected dehydro-β-amino acids was developed. The key to exclusive β-selectivity was the use of diethylzinc as a reductant in the presence of a magnesium salt. The reaction was conducted with bis(acetylacetonato)nickel(II) instead of costly and sensitive bis(1,5-cyclooctadiene)nickel(0). In addition, the optimized ligand was inexpensive 1,5-cyclooctadiene. Investigation of the substrate scope revealed that both nitrogen and alkyne substituents have marked effects on the reaction efficiency. We obtained experimental clues that indicated the formation of a vinylzinc intermediate that forms a C–C bond with CO2.
Synthesis and Hybridization Properties of Covalently Mercurated and Palladated Oligonucleotides
Authors: Ukale Dattatraya , Maity Sajal , Hande Madhuri , Lönnberg Tuomas
Published: May 2019

Covalent metalation of the base moieties affords a new class of modified oligonucleotides. These organometallic oligonucleotides share many properties, notably increased hybridization affinity conferred by metal-mediated base pairing, with oligonucleotides incorporating coordinative transition-metal complexes. They are, however, set apart by their ability to retain the transition-metal ion even at extreme dilution. Such stability towards dissociation would be desirable in DNA nanotechnology and necessary in therapeutic applications. Herein we describe our efforts towards preparation and characterization of covalently mercurated and palladated oligonucleotides, highlighting in particular our recent contribution on the synthesis and potential applications of oligonucleotides incorporating dimercurated artificial nucleobases.

1 Introduction

2 Synthesis of Covalently Mercurated and Palladated Oligonucleotides

3 Hybridization Properties of Covalently Mercurated and Palladated Oligonucleotides

4 Outlook
Combined Alkylating Agents as a Resolution for Highly Selective N-Alkylation of 2-Hydroxybenzaldehyde Acylhydrazones
Authors: Zhang Qiao Y. , Cheng Xin J. , Zhao Xin Y. , Wu La M. , Jin Long F. , Zhang Hui J.
Published: May 2019

Although 2-hydroxybenzaldehyde acylhydrazones, such as salicylaldehyde acylhydrazones, are intriguing bioactive molecules, few of their N-alkylated derivatives are known, and only methyl analogues have been reported previously. We achieved selective N-alkylation of 2-hydroxybenzaldehyde acylhydrazones, as their Fe(III) complexes, by using combinations of alkylating agents (for example, an alkyl bromide and a dialkyl sulfate). Fifteen substrates were examined, and 45 new 2-hydroxybenzaldehyde acyl(alkyl)hydrazones were synthesized in moderate to good yields. In all cases, the target products were obtained exclusively, and no O-alkylation byproducts were produced. The method provides an efficient way of preparing 2-hydroxybenzaldehyde acyl(alkyl)hydrazones.
Treatment of Chronic Patellar Tendon Rupture with Hamstrings Tendon Autograft
Authors: Valianatos Panagiotis , Papadakou Evgenia , Erginoussakis Dimitrios , Kampras Dimitrios , Schizas Nikitas , Kouzoupis Anastasios
Published: May 2019

We describe a new simple reconstruction for neglected chronic ruptures of patellar tendon using ipsilateral hamstrings tendon autograft. This has been validated in thirteen patients with mean follow up six years resulting in favorable outcome. Thirteen patients with mean age 58.2 years (range 30–64 years) presented with chronic patellar tendon rupture. They all underwent patellar tendon reconstruction using ipsilateral hamstrings tendon autograft. The average time from injury was 10 months (range 3–20 months). The cause of rupture was fall from height or after TKA and the preoperative Lysholm score was 65 (range 50–80). Postoperatively with a mean follow up of six years (range 5–7 years), all patients had a stable knee with mean flexion of 123°, extension lag 0°, and Insall-Salvati index 1.2. Quadriceps power was regained in 8 cases to 5/5 and in 5 cases to 4/5. No complications were inspected. The postoperative Lysholm score was 93 (range 89–95). Patellar tendon reconstruction using ipsilateral hamstrings as free autograft, consists an effective treatment option for chronic neglected patellar tendon ruptures. Our technique has favorable clinical outcome, complications are not expected, and consist a simple and anatomic reconstruction with a powerful graft, without the requirement for allograft or implants.
Reconstruction with Custom Unicondylar Hemiarthroplasty following Tumor Resection: A Case Series and Review of the Literature
Authors: Ippolito Joseph A. , Campbell Megan L. , Siracuse Brianna L. , Benevenia Joseph
Published: May 2019

For patients with tumors of the distal femur, options for limb salvage include tumor resection followed by reconstruction. While reconstruction commonly involves a distal femoral replacement, careful selection of patients with tumor involvement limited to a single condyle may be candidates for reconstruction with distal femur hemiarthroplasty. In these procedures, resection spares considerably more native anatomy. Three consecutive patients who underwent resection and reconstruction at the distal femur with custom unicondylar hemiarthroplasty are presented in this case series at a mean follow-up of 45 months (range, 26–78). In two cases, prostheses were utilized as a secondary procedure after failure of initial reconstruction. In one case, the custom prosthesis was utilized as the primary method of reconstruction. Mean Musculoskeletal Tumor Society disease-specific scores were 26.7 (range, 25–28). All patients achieved a return to full weight bearing, activities of daily living, and functional range of motion. In appropriately selected patients with tumors of the distal femur, reconstruction with custom unicondylar hemiarthroplasty provides benefits including optimal function postoperatively via preservation of tumor-free bone and ligamentous structures. Additionally, maintenance of greater bone stock may confer benefits to patients with pathology at a high likelihood for recurrence and need for subsequent procedures.
Rheumatoid Lymphedema Successfully Treated with Lymphaticovenular Anastomosis: A Case Report
Authors: Ichinose Yuko , Yasunaga Yoshichika , Yuzuriha Shunsuke
Published: May 2019

Background A 76-year-old woman presented with rheumatoid lymphedema (RL) distal to the left elbow after 20 years of affliction with rheumatoid arthritis (RA). Although the RA was controlled by medication, the patient could not receive full-scale compression therapy for her edema with a medium-pressure compression sleeve (pressure: 20–25 mm Hg) due to hand dysfunction caused by long-term RA.

Methods Lymphaticovenular anastomosis (LVA) was performed after compression therapy with a low-pressure sleeve (14–18 mm Hg) proved ineffective for edema relief. Two anastomoses were created in a side-to-end fashion at the cubital fossa.

Results The edema improved rapidly after LVA and was maintained with a low-pressure compression sleeve.

Conclusion LVA represents a treatment option for remaining RL in RA treatment. As some RL patients are ineligible for full-scale compression therapy due to hand dysfunction caused by RA, LVA may help to reduce RL and enable edema management using a low-pressure compression garment without concern for hand dysfunction.
A new SU(2) anomaly
Authors: Wang Juven , Wen Xiao-Gang , Witten Edward
Published: May 2019

A familiar anomaly affects SU(2) gauge theory in four dimensions: a theory with an odd number of fermion multiplets in the spin 1/2 representation of the gauge group, and more generally in representations of spin 2r + 1/2, is inconsistent. We describe here a more subtle anomaly that can affect SU(2) gauge theory in four dimensions under the condition that fermions transform with half-integer spin under SU(2) and bosons transform with integer spin. Such a theory, formulated in a way that requires no choice of spin structure, and with an odd number of fermion multiplets in representations of spin 4r + 3/2, is inconsistent. The theory is consistent if one picks a spin or spinc structure. Under Higgsing to U(1), the new SU(2) anomaly reduces to a known anomaly of “all-fermion electrodynamics.” Like that theory, an SU(2) theory with an odd number of fermion multiplets in representations of spin 4r + 3/2 can provide a boundary state for a five-dimensional gapped theory whose partition function on a closed five-manifold Y is (−1)∫Yw2w3. All statements have analogs with SU(2) replaced by Sp(2N). There is also an analog in five dimensions.
Decay mechanism of optical phonons in γ-CuI
Authors: He Haiying , Zhang Zhaojun
Published: May 2019

Temperature-dependent frequencies and linewidths of transverse-optical (TO) and longitudinal-optical (LO) in γ–CuI were fitted according to the anharmonic phonon coupling theory. The results indicate that the asymmetric three-phonon and symmetric four-phonon processes are both responsible for the decay of LO and TO phonons in γ–CuI. Additionally, the possible decay channels are also suggested as: TO (135 cm-1) →LA (∼100 cm-1) +TA (35 cm-1) at L point and three TA (45cm-1) at X point; LO (152 cm-1) → LA (∼102 cm-1) +TA (∼50 cm-1) or three TA (50cm-1) at K point in Brillouin zone. These results are meaningful for the future applications of γ–CuI in optoelectronic and electronic fields.
Resonant interaction of energetic ions with bulk-ion plasma micro-turbulence
Authors: Di Siena A. , Görler T. , Poli E. , Bilato R. , Doerk H. , Zocco A.
Published: May 2019

A significant fast ion-induced stabilization is observed in linear and nonlinear GENE gyrokinetic simulations, which can be attributed to a resonant interaction between energetic particles and the main-ion-temperature gradient driven plasma turbulence. Elaborating on the findings in Di Siena et al. [Nucl. Fusion 58, 054002 (2018)], a detailed study of this mechanism is conducted for realistic JET-like parameters. In view of further exploitation of the beneficial role of energetic ions and corresponding confinement optimization, linear scans over the main fast ion parameters and magnetic plasma geometry are performed. All these results can be reproduced with a reduced Vlasov-Poisson theoretical model and be explained in terms of modifications on the fast ion energy production/dissipation in the energy balance equation. Finally, despite the essentially linear nature of the resonant interaction, a corresponding nonlinear analysis is also performed and its main dependences are captured with a quasi-linear model.
Thermoelectric properties of p-type SrTiO3/graphene layers nanohybrids
Authors: Nath Chandrani , Chueh C.-Y. , Kuo Y.-K. , Singh J. P.
Published: May 2019

We studied the thermoelectric properties of SrTiO3 and graphene layer(s) (GL) nanohybrids between 10 and 300 K as a function of GL loading. Thermopower measurements indicate that the nanohybrids are p-type materials with low S values of about 11–21 μV/K at room temperature. The p-type behavior of the hybrids has been ascribed to the electron accepting nature of GL that leads to the SrTiO3/GL system hole conducting. The temperature dependence of electrical resistivity shows a degenerate semiconducting behavior as indicated by its weak and negative temperature coefficient of resistivity. The room-temperature resistivity decreases by about three orders of magnitude with GL loading ranging from about 102 to 10−1 Ω cm. These nanohybrids exhibit an amorphous behavior of thermal conductivity with a low temperature plateau and a quasilinear increase at high temperatures. The thermoelectric performance ZT is estimated to be of the order of 10−5 at room temperature for 10% GL loaded SrTiO3.
Threshold displacement energies and displacement cascades in 4H-SiC: Molecular dynamic simulations
Authors: Li Weimin , Wang Lielin , Bian Liang , Dong Faqin , Song Mianxin , Shao Jianli , Jiang Shuqing , Guo Hui
Published: May 2019

Molecular dynamic (MD) simulations were used to study threshold displacement energy (TDE) surface and Si displacement cascades in 4H-SiC system. To figure out the role of different Wyckoff sites in determining the TDE values, both Si and C atoms in 2a and 2b Wyckoff sites were separately considered as the primary knocked atoms (PKA). The initial kinetic energy was then distributed along 146 different crystallographic directions at 10 K. TDE surface appeared highly anisotropic for Si and C displacements along different crystallographic directions. The TDE was determined as 41 eV for Si and 16 eV for C. The average values of TDE over two Wyckoff sites were estimated to 66 eV for Si PKA and 24 eV for C PKA. The displacement cascades produced by Si recoils of energies spanning varied from 5 keV to 50 keV at 300 K. To count the number of point defects using Voronoi cell analysis method, the crystal structure of 4H–SiC was transformed from hexagonal to orthorhombic. It was found that the surviving defects at the end of cascades were dominated by C vacancies and interstitials due to low displacement energies of C atoms and greater number of C interstitials when compared to C vacancies.
Electrostatic solitary waves in ion beam neutralization
Authors: Lan C. , Kaganovich I. D.
Published: May 2019

The excitation and propagation of electrostatic solitary waves (ESWs) are observed in two-dimensional particle-in-cell simulations of ion beam neutralization by electron injection by a filament. Electrons from the filament are attracted by positive ions and bounce inside the ion beam pulse. Bouncing back and forth electron streams start to mix, creating two-stream instability. The instability saturates with the formation of ESWs. These ESWs reach several centimeters in longitudinal size and are stable for a long time (≫τb, the duration of the ion beam pulse). The excitation of large-amplitude ESWs reduces the degree of neutralization of the ion beam pulse. In addition, the dissipation of ESWs causes heating of neutralizing electrons and their escape from the ion beam, leading to a further reduction of neutralization degree. The appearance of these waves can explain the results of previous experimental studies, which showed poor ion beam neutralization by electro-emitting filaments.
Comparing chaotic and random dynamical systems
Authors: Young Lai-Sang
Published: May 2019

This is a slightly expanded version of the plenary lecture the author gave at the International Congress on Mathematical Physics 2018 in Montreal, Canada. Reported are some work of the author and collaborators as well as related results of others on two kinds of dynamical systems: the first kind is deterministic (in the sense that nothing is left to chance) but is chaotic and unpredictable, and the second kind has a stochastic component in addition to a purely deterministic one. These two kinds of dynamical systems are compared and contrasted. The main points are that time series of observations from chaotic deterministic systems obey some of the same probabilistic limit laws as genuinely random stochastic processes, but random dynamical systems enjoy nicer properties and are technically more tractable.
Fast prediction of electron-impact ionization cross sections of large molecules via machine learning
Authors: Zhong Linlin
Published: May 2019

The theoretical determination of electron-impact ionization cross section (Qion) for a molecule requires ab initio computation, which is time-consuming for large molecules. We propose a machine learning based method to construct a model for predicting Qion of large molecules without the high-cost ab initio calculation. The model is learned from the data composed of the calculated Qion of the small molecules with fewer constituent atoms and the electron numbers of the corresponding molecules in a train set by a support vector machine. The radial basis function is set as a kernel function to map data to a higher dimensional space. The grid search with 5-fold cross-validation is performed to find optimal hyperparameters in the learning model. The prediction on the test sets composed of CF4, C3F8, SF6, C6, C6F12, and C6F12O shows that this data-driven model can generate well-agreed Qion and has good generalization performance.
An automated on-demand liquid marble generator based on electrohydrodynamic pulling
Authors: Sreejith Kamalalayam Rajan , Ooi Chin Hong , Jin Jing , Dao Dzung Viet , Nguyen Nam-Trung
Published: May 2019

Liquid marble is a recently emerging digital microfluidic platform with a wide range of applications. Conventional liquid marbles are synthesized by coating liquid droplets with a thin layer of hydrophobic powder. Existing and emerging applications of liquid marbles require a contamination-free synthesis of liquid marbles with a high degree of reproducibility of their volume. Despite this requirement, the synthesis of liquid marbles has been still carried out manually. Manual production of liquid marbles leads to inconsistent volume and the possibility of contamination. The synthesis of liquid marbles with submicroliter volume is difficult to achieve and prone to large errors. This paper discusses the design and development of the first automated on-demand liquid marble generator with submicroliter capability. The device utilizes electrohydrodynamic pulling of liquid droplets on to a hydrophobic powder bed and subsequently coats them with the hydrophobic powder to synthesize liquid marbles of a desired volume.
Adaptive neural network control for fractional-order PMSM with time delay based on command filtered backstepping
Authors: Lu Senkui , Wang Xingcheng , Li Yanan
Published: May 2019

In this paper, an adaptive neural network (NN) control based on command filtered backstepping approach is presented for fractional-order permanent magnet synchronous motor (PMSM) with parameter uncertainties and unknown time delays. For the convenience of controller design, the state trajectories and phase portrait of the system are investigated to analyze the dynamics of the fractional-order PMSM. The unknown parameters and load torque disturbance in the system dynamics are approximated by using NNs, and the number of adaptive laws for the weight vector is curtailed to just one. To ensure orderly decay of the desired error trajectory, a model reference technique is also introduced to backstepping approach. The command filter technique, which can solve the “explosion of complexity” issue of backstepping, is extended to fractional-order nonlinear systems, and the error compensation mechanism is designed to overcome the shortcoming of the classical dynamics surface filter. The effects of time delays uncertainties are suppressed by employing proper Lyapunov-Krasovskii functions. From the Lyapunov stability theory, the design of the controller ensures all signals in the fractional-order PMSM system remain bounded, while the output error converges to a small region of the origin. Numerical simulations are given to show the correctness and effectiveness of the new design technique.
Impedance spectroscopy characterization of neutron irradiated thermoelectric modules for space nuclear power
Authors: Mesalam Ramy , Williams Hugo R. , Ambrosi Richard M. , Kramer Daniel P. , Barklay Chadwick D. , García-Cañadas Jorge , Stephenson Keith , Weston David P.
Published: May 2019

The European Space Agency is currently supporting the research and development of advanced radioisotope power systems utilising thermoelectric modules. The performance of thermoelectric modules following exposure to neutron radiation is of significant interest due to the likely application of radioisotope thermoelectric generators in deep space exploration or planetary landers requiring prolonged periods of operation. This study utilises impedance spectroscopy to characterise the effects of neutron irradiation on the performance of complete thermoelectric modules, as opposed to standalone material. For a 50 We americium-241 radioisotope thermoelectric generator design, it is estimated that the TE modules could be exposed to a total integrated flux of approximately 5 × 1013 neutrons cm-2 (>1 MeV). In this study, an equivalent neutron dose was simulated experimentally via an acute 2-hour exposure in a research pool reactor. Bi2Te3-based thermoelectric modules with different leg aspect ratios and microstructures were investigated. Gamma-ray spectroscopy was initially used to identify activated radionuclides and hence quantify irradiation induced transmutation doping. To evaluate the thermoelectric properties pre- and post-irradiation, impedance spectroscopy characterization was employed. Isochronal thermal annealing of defects imparted by the irradiation process, revealed that polycrystalline based modules required significantly higher temperature than those with a monolithic microstructure. Whilst this may indicate a greater susceptibility to neutron irradiation, all tested modules demonstrated sufficient radiation hardness for use within an americium-241 radioisotope thermoelectric generator. Furthermore, the work reported demonstrates that impedance spectroscopy is a highly capably diagnostic tool for characterising the in-service degradation of complete thermoelectric devices.
Influence of the quality factor on the signal to noise ratio of magnetoelectric sensors based on the delta-E effect
Authors: Spetzler Benjamin , Kirchhof Christine , Reermann Jens , Durdaut Phillip , Höft Michael , Schmidt Gerhard , Quandt Eckhard , Faupel Franz
Published: May 2019

Recently, there has been much interest in magnetoelectric magnetic field sensors utilizing the delta-E effect. Such sensors are fully integrable and combine the advantages of high sensitivity at low frequencies with broad bandwidth. Here, we report the influence of the quality factor Q on the signal-to-noise ratio of magnetoelectric magnetic field sensors utilizing the delta-E effect. The sensor consists of a silicon cantilever covered by a magnetostrictive and a piezoelectric thin film. The magnetization-dependent elasticity of the magnetostrictive film leads to detuning of the sensor's resonance, which is excited and read out via the piezoelectric layer. The signal-to-noise ratio is experimentally analyzed as a function of the quality factor, the excitation amplitude and the signal frequency. The results are compared with a signal and noise model to describe general tendencies. The model demonstrates that, in contrast to the conventional direct operation of magnetoelectric sensors, an improvement in the limit of detection proportional to Q3/2 can be achieved if thermal-mechanical noise is dominant. The relationship still holds for frequencies far away from the resonance frequency. This reveals the potential for improving the limit of detection significantly by increasing the quality factor, if magnetic and electronic noise can be suppressed.
Expanding on bond dissociation energy of gold
Authors: Kish Stacy W.
Published: May 2019

New paper explores the bond dissociation energy of gold dimer cations.
Formation of spectra of saturated-absorption resonances on closed transitions in the spectroscopy of unidirectional waves
Authors: Saprykin E.G. , Chernenko A.A.
Published: May 2019

The formation of spectra of saturated-absorption resonances on the atomic transitions with level momenta J = 0 → J = 1 and J = 1 → J = 2 are investigated, both numerically and analytically, by the method of unidirectional linearly polarised laser waves in order to determine how the transition openness (radiation branching) affects these spectra. It is shown that, along with quantitative changes, determined by the relaxation constants of levels, value of their splitting, polarisation orientation, and wave intensities, the spectra undergo qualitative changes with a change in the degree of atomic transition openness.
Thermodynamically equilibrium quantum vortices in superfluid liquids
Authors: Nemirovskii S.K.
Published: May 2019

The thermodynamic equilibrium is studied for a system of quantised vortices in superfluid liquids in the presence of a counterflow of the normal and superfluid components. The partition function is calculated, which takes into account various configurations of the vortex filaments, as well as the distribution of loops in length. The dependence of the density of vortex filaments on the applied counterflow velocity is discussed.
Effect of dipole blockade on the laser excitation spectra of mesoscopic ensembles of cold Rydberg atoms
Authors: Ryabtsev I.I. , Beterov I.I. , Tretyakov D.B. , Yakshina E.A. , Entin V.M.
Published: May 2019

The results of theoretical calculations of the multiatom laser excitation spectra of Rydberg atoms under conditions of a dipole blockade are presented, and the effect of the laser radiation line width and the interaction energy of Rydberg atoms on the dipole blockade completeness degree is discussed. It is shown that in order to increase the fidelity of performing quantum gates based on a dipole blockade, it is necessary to use resonance dipole − dipole interaction and exciting laser radiation with a line width smaller than 10 kHz.
Temperature drift contribution to frequency instability of silicon Fabry – Perot cavities
Authors: Zhadnov N.O. , Vishnyakova G.A. , Kudeyarov K.S. , Kryuchkov D.S. , Khabarova K.Yu. , Kolachevsky N.N.
Published: May 2019

A contribution of a temperature drift near the silicon thermal expansion coefficient zero point to the fractional frequency instability of a silicon cavity is analysed. The thermal expansion coefficient of silicon is measured by an optical method near the zero point T
0 = 123 K. It is shown that the frequency instability due to cavity temperature drifts observed in an experiment does not exceed a thermal noise limit at averaging intervals of up to 20 s.
Conversion of nuclear spin isomers of water molecules under ultracold conditions of space
Authors: Chapovsky P.L.
Published: May 2019

The conversion rate of nuclear spin isomers of water molecules in space is calculated using the model of quantum relaxation in the absence of particle collisions. The model is based on the intramolecular mixing of the ortho and para states of H2O by the spin-rotation interaction and on the interruption of the mixing by radiative transitions of a molecule in a thermal radiation field. The lifetime of water isomers at a thermal radiation temperature T = 50 K is ∼2 × 107 years, and at a temperature T = 100 K it is 3 × 106 years. The lifetimes of the spin isomers of water molecules are found to be large, but still smaller, for example, than the age of the Solar System. The proposed process of conversion of the spin isomers of water molecules is important for areas of space with low (n < 1 cm−3) particle concentrations.
Downward the temperature scale
Authors: Vinogradov V.A. , Karpov K.A. , Savelyeva S.V. , Turlapov A.V.
Published: May 2019

Approaches to deep cooling of atomic gases are discussed. The delta kick cooling and adiabatic expansion as well as the limitations of the former are considered. The applicability of hollow optical dipole traps based on radiation of near-resonance transition frequency in atoms is shown. The possibility of designing such traps with a size of ∼1 mm is analysed and the prospects for their use for cooling atoms by evaporation and adiabatic expansion are discussed.
Quantum geometric phase under pre- and post-selection
Authors: Yakovleva T.S. , Rostom A.M. , Tomilin V.A. , Ilichev L.V.
Published: May 2019

We consider a quantum system subjected to a controlled phase transformation and interaction with the environment in between the acts of selection, which leads to the emergence of interference effects. It is shown that the shift of the dependence of the statistics of contacts’ information with the environement on the controlled phase shift can be interpreted as a geometric phase. This interpretation is consistent with the known operational approach to the geometric phase. As a result, we suggest generalising the operational approach to the realm of pre- and post-selected quantum states.
Stomatal conductance responses to evaporative demand conferred by rice drought-yield quantitative trait locus qDTY12.1
Authors: Henry Amelia , Stuart-Williams Hilary , Dixit Shalabh , Kumar Arvind , Farquhar Graham
Published: May 2019

Rice quantitative trait locus (QTL) qDTY12.1 is a major-effect drought yield QTL that was identified from a cross of Vandana (recipient parent) and Way Rarem (donor parent) through breeding efforts to improve rice yield under upland drought stress conditions. The two main physiological effects previously observed to be related to the presence of qDTY12.1 were (i) increased lateral root growth, and (ii) increased transpiration efficiency. Since relatively more progress has thus far been made on characterising the lateral root growth response related to qDTY12.1, the present study focussed on characterising how qDTY12.1 confers higher transpiration efficiency under upland drought stress in the Vandana background. In a series of field experiments in which stomatal conductance was measured across different times of day in four qDTY12.1 near isogenic lines (NILs), the NILs and Way Rarem showed consistently higher stomatal conductance than Vandana under conditions of low vapour pressure deficit (VPD) and low photosynthetically active radiation (PAR), and consistently lower stomatal conductance than Vandana under high VPD and high PAR. Leaf δ18O was higher in the qDTY12.1 NIL than in Vandana, and although this trend was previously observed for leaf δ13C it appeared to be more consistent across measurement dates and treatments for leaf δ18O. The qDTY12.1 NILs and Way Rarem tended to show greater large vein to small vein interveinal distance and mesophyll area than Vandana, also consistent across treatments. In terms of aquaporin-related plant hydraulics, variation among NILs in terms of aquaporin inhibition of root hydraulic conductivity (Lpr) was observed, with the highest-yielding NIL showing a lack of Lpr inhibition similar to Way Rarem. The results reported here suggest that the effects of qDTY12.1 are in response not only to soil moisture, but also to atmospheric conditions. An interaction among multiple mechanisms including leaf anatomy and aquaporin function appear to confer the transpiration efficiency effect of qDTY12.1.
Impact of agrarian practices and some pastoral uses on vegetation in Algerian steppe rangelands
Authors: Hammouda R. F. , Huguenin J. , Julien L. , Nedjraoui D.
Published: May 2019

The decline in steppe vegetation in Algeria was first reported in the mid-20th century, and for many years was attributed to recurrent droughts. Hypotheses suggesting that this decline was a consequence of human activities emerged in the 1970s – a time of major socioeconomic trends in the region. Changes such as strong population growth, sedentarisation, herd size increases and use of pasture land for crops, all had considerable impact on rangeland vegetation. The aim of the present work was to identify heterogeneity in the pasture vegetation of a given ‘territory’ (in the sense of a ‘terroir’), or biophysical environment (including meteorological), taking into account rangeland distribution, land use changes and herd management in the Aflou region of Algeria. Characterisation and mapping of the vegetation and its environment in the study area led to the hypothesis that, apart from some very slight soil differences, heterogeneity in rangeland vegetation appeared mainly related to human impacts. Bertin’s Semiology of Graphics was used to analyse the results, and indicated a major decline in vegetation productivity and biodiversity in the steppe rangelands of the study zone. Beyond this general trend in the municipal territory studied, areas were found with contrasting flora communities, with some showing relatively stable plant communities, while other areas had some plant communities that had undergone regressive succession. Grazing conditions and the proximity of ploughed land were responsible for these different vegetation situations.
Multiple
SCN5A
variant enhancers modulate its cardiac gene expression and the QT interval
Authors: Kapoor Ashish , Lee Dongwon , Zhu Luke , Soliman Elsayed Z. , Grove Megan L. , Boerwinkle Eric , Arking Dan E. , Chakravarti Aravinda
Published: May 2019

The rationale for genome-wide association study (GWAS) results is sequence variation in
cis
-regulatory elements (CREs) modulating a target gene’s expression as the major cause of trait variation. To understand the complete molecular landscape of one of these GWAS loci, we performed in vitro reporter screens in cardiomyocyte cell lines for CREs overlapping nearly all common variants associated with any of five independent QT interval (QTi)-associated GWAS hits at the
SCN5A
-
SCN10A
locus. We identified 13 causal CRE variants using allelic reporter activity, cardiomyocyte nuclear extract-based binding assays, overlap with human cardiac tissue DNaseI hypersensitive regions, and predicted impact of sequence variants on DNaseI sensitivity. Our analyses identified at least one high-confidence causal CRE variant for each of the five sentinel hits that could collectively predict
SCN5A
cardiac gene expression and QTi association. Although all 13 variants could explain
SCN5A
gene expression, the highest statistical significance was obtained with seven variants (inclusive of the five above). Thus, multiple, causal, mutually associated CRE variants can underlie GWAS signals.
Atomic-scale determination of spontaneous magnetic reversal in oxide heterostructures
Authors: Saghayezhian M. , Kouser Summayya , Wang Zhen , Guo Hangwen , Jin Rongying , Zhang Jiandi , Zhu Yimei , Pantelides Sokrates T. , Plummer E. W.
Published: May 2019

Significance

Transition metal oxide interfaces have shown extraordinary promise in the quest to design materials with custom electronic, magnetic, and optical properties. In rare cases, interfaces exhibit electronic and magnetic properties that are radically different from those of the components. An example is the emergent two-dimensional electron gas between two insulators. In this work, we show that the interface of a nonmagnetic oxide substrate and a ferromagnetic metallic thin film possesses a local antiferromagnetic coupling which controls the reversal of the entire film’s ferromagnetic ordering. Electron microscopy and quantum calculations elucidate the atomic-scale origin of the observed phenomena, and demonstrate that local nonstoichiometry and structure are the key factors in interfacial phenomena.
Sphingosine-1-phosphate receptor 1 activation in astrocytes contributes to neuropathic pain
Authors: Chen Zhoumou , Doyle Timothy M. , Luongo Livio , Largent-Milnes Tally M. , Giancotti Luigino Antonio , Kolar Grant , Squillace Silvia , Boccella Serena , Walker John K. , Pendleton Alexander , Spiegel Sarah , Neumann William L. , Vanderah Todd W. , Salvemini Daniela
Published: May 2019

Significance

Understanding the cellular and molecular pathways of neuropathic pain is fundamental to discovering classes of non-opioid analgesics. Emerging evidence implicates altered sphingolipid metabolism and elevated levels of sphingosine-1-phosphate (S1P) in the spinal cord in the persistence of neuropathic pain, but its neuropharmacology and pathways engaged are poorly understood. Using a multidisciplinary approach, we provide evidence that S1P drives neuropathic pain by selectively activating the S1P receptor subtype 1 (S1PR1) in astrocytes. Inhibiting S1PR1 attenuated and reversed neuropathic pain by engaging the potent anti-inflammatory cytokine, interleukin 10. Our findings represent a paradigm shift in the understanding of S1PR1 signaling that has implications on the future development of S1PR1 antagonists as a promising class of nonnarcotic analgesics.
Muscle-like fatigue-resistant hydrogels by mechanical training
Authors: Lin Shaoting , Liu Ji , Liu Xinyue , Zhao Xuanhe
Published: May 2019

Significance

The combinational muscle-like properties including high fatigue resistance, high strength, superior compliance, and high water content are highly desirable for various applications of soft biomaterials such as hydrogels. These combinational properties, largely attributed to the aligned nanofibrils in natural muscles, have not been achieved in synthetic hydrogels. Here, we propose a strategy of mechanical training to impart hydrogels with an extremely high fatigue threshold (1,250 J/m
2
) and strength (5.2 MPa), while maintaining a high water content (84 wt %) and a low Young’s modulus (200 kPa), reaching combinational muscle-like properties with aligned nanofibrillar architectures. We further achieve isotropically enhanced properties by three-dimensionally printing the hydrogels into microstructures.
MRGPRX4 is a G protein-coupled receptor activated by bile acids that may contribute to cholestatic pruritus
Authors: Meixiong James , Vasavda Chirag , Snyder Solomon H. , Dong Xinzhong
Published: May 2019

Significance

Cholestatic itch is a debilitating symptom that affects hundreds of thousands of patients every year, drastically decreasing patient quality of life. Additional therapeutic targets are needed, as current therapies are ineffective for many patients. In recent years, the Mas-related G protein-coupled receptor (MRGPR) family of receptors has been linked to itch. Here, we determine that MRGPRX4 is specifically activated by numerous bile acids (BAs) up-regulated in cholestatic patient sera. To test the relevance of these findings in vivo, we generated humanized mice expressing
MRGPRX4
in sensory neurons. MRGPRX4
+
humanized mice display higher levels of itch in response to injection of BAs and in a mouse model of cholestasis, indicating that MRGPRX4 could play a role in cholestatic itch.
Homozygosity for
TYK2
P1104A underlies tuberculosis in about 1% of patients in a cohort of European ancestry
Authors: Kerner Gaspard , Ramirez-Alejo Noe , Seeleuthner Yoann , Yang Rui , Ogishi Masato , Cobat Aurélie , Patin Etienne , Quintana-Murci Lluis , Boisson-Dupuis Stéphanie , Casanova Jean-Laurent , Abel Laurent
Published: May 2019

Significance

Only ∼5% of individuals infected with
Mycobacterium tuberculosis
develop clinical TB in their lifetime. We previously reported that homozygosity for the P1104A variant of the
TYK2
gene, found in ∼1/600 Europeans and ∼1/5,000 individuals from elsewhere (except East Asians and sub-Saharan Africans), was a monogenic etiology of TB in a genetically heterogeneous cohort of patients from non-European countries endemic for TB. Making use of the UK Biobank cohort, we report a strong enrichment of P1104A homozygotes in a British sample of 620 patients with TB (1%), relative to 114,473 controls (0.2%), 97% of whom were of European descent. Our findings suggest that homozygosity for the P1104A
TYK2
variant may underlie TB in ∼1% of European patients.
Donor and acceptor characteristics of native point defects in GaN
Authors: Xie Zijuan , Sui Yu , Buckeridge John , Catlow C Richard A , Keal Thomas W , Sherwood Paul , Walsh Aron , Farrow Matthew R , Scanlon David O , Woodley Scott M , Sokol Alexey A
Published: May 2019

The semiconducting behaviour and optoelectronic response of gallium nitride is governed by point defect processes, which, despite many years of research, remain poorly understood. The key difficulty in the description of the dominant charged defects is determining a consistent position of the corresponding defect levels, which is difficult to derive using standard supercell calculations. In a complementary approach, we take advantage of the embedded cluster methodology that provides direct access to a common zero of the electrostatic potential for all point defects in all charge states. Charged defects polarise a host dielectric material with long-range forces that strongly affect the outcome of defect simulations; to account for the polarisation, we couple embedding with the hybrid quantum mechanical/molecular mechanical approach and investigate the structure, formation and ionisation energies, and equilibrium concentrations of native point defects in wurtzite GaN at a chemically accurate hybrid-density-functional-theory level. N vacancies are the most thermodynamically favourable native defects in GaN, which contribute to the n-type character of as-grown GaN but are not the main source, a result that is consistent with experiment. Our calculations show no native point defects can form thermodynamically stable acceptor states. GaN can be easily doped n-type, but, in equilibrium conditions at moderate temperatures acceptor dopants will be compensated by N vacancies and no significant hole concentrations will be observed, indicating non-equilibrium processes must dominate in p-type GaN. We identify spectroscopic signatures of native defects in the infrared, visible and ultraviolet luminescence ranges and complementary spectroscopies. Crucially, we calculate the effective-mass-like-state levels associated with electrons and holes bound in diffuse orbitals. These levels may be accessible in competition with more strongly-localised states in luminescence processes and allow the attribution of the observed 3.46 and 3.27 eV UV peaks in a broad range of GaN samples to the presence of N vacancies.
Hybrid graphene-manganite thin film structure for magnetoresistive sensor application
Authors: Lukose Rasuole , Zurauskiene Nerija , Balevicius Saulius , Stankevic Voitech , Keršulis Skirmantas , Plausinaitiene Valentina , Navickas Romualdas
Published: May 2019

An increasing demand of magnetic field sensors with high sensitivity at room temperatures and spatial resolution at micro-nanoscales has resulted in numerous investigations of physical phenomena in advanced materials, and fabrication of novel magnetoresistive devices. In this study the novel magnetic field sensor based on combination of a single layer graphene (SLG) and thin nanostructured manganite La0.8Sr0.2MnO3 (LSMO) film—hybrid graphene-manganite (GM) structure, is proposed and fabricated. The hybrid GM structure employs the properties of two materials—SLG and LSMO—on the nanoscale level and results in the enhanced sensitivity to magnetic field of the hybrid sensor on the macroscopic level. Such result is achieved by designing the hybrid GM sensor in a Wheatstone half-bridge which enables to employ in the device operation two effects of nanomaterials—large Lorentz force induced positive magnetoresistance of graphene and colossal negative magnetoresistance of nanostructured manganite film, and significantly increase the sensitivity S of the hybrid GM sensor in comparison with the individual SLG and LSMO sensors: S = 5.5 mV T−1 for SLG, 14.5 mV T−1 for LSMO and 20 mV T−1 for hybrid GM at 0.5 T, when supply voltage was 1.249 V. The hybrid GM sensor operates in the range of (0.1–2.3) T and has lower sensitivity to temperature variations in comparison to the manganite sensor. Moreover, it can be applied for position sensing. The ability to control sensor’s characteristics by changing technological conditions of the fabrication of hybrid structure and tuning the nanostructure properties of manganite film is discussed.
Manufacturing technologies toward extreme precision
Authors: Zhang Zhiyu , Yan Jiwang , Kuriyagawa Tsunemoto
Published: May 2019

Precision is one of the most important aspects of manufacturing. High precision creates high quality, high performance, exchangeability, reliability, and added value for industrial products. Over the past decades, remarkable advances have been achieved in the area of high-precision manufacturing technologies, where the form accuracy approaches the nanometer level and surface roughness the atomic level. These extremely high precision manufacturing technologies enable the development of high-performance optical elements, semiconductor substrates, biomedical parts, and so on, thereby enhancing the ability of human beings to explore the macro- and microscopic mysteries and potentialities of the natural world. In this paper, state-of-the-art high-precision material removal manufacturing technologies, especially ultraprecision cutting, grinding, deterministic form correction polishing, and supersmooth polishing, are reviewed and compared with insights into their principles, methodologies, and applications. The key issues in extreme precision manufacturing that should be considered for future R&D are discussed.
Storage Age of RBCs Transfused by a Prehospital Patient Transport Program vs the Hospital Emergency Department
Authors: Gehrie Eric A , Szklarski Penny C , Nooner Kevin , Booth Garrett S
Published: May 2019

Objectives

Recently published data suggest that transfusion of RBCs stored for 22 days or longer was associated with increased mortality among massively transfused trauma patients.

Methods

We performed a 24-month retrospective review of medical transport service transfusion records and a 2-month, overlapping review of transfusions of uncrossmatched RBCs in the emergency department.

Results

RBC units issued to the transport program were older than RBC units issued to the emergency department trauma refrigerator (10.6 vs 8.7 days, P < .001). Similarly, RBC units were older at the time of transfusion during transport compared with the emergency department (20.3 vs 14.3 days, P < .001).

Conclusions

Transport programs and blood banks should jointly review their RBC inventory management programs. Issuing RBCs to a medical transport program is a logistical challenge that, unless actively managed, may not ensure access to blood that is as fresh as blood in the emergency department.
Development and validation of a medication regimen complexity scoring tool for critically ill patients
Authors: Gwynn Morgan E , Poisson Margaret O , Waller Jennifer L , Newsome Andrea Sikora
Published: May 2019

Purpose

The purpose of this study was to develop and validate a novel medication regimen complexity–intensive care unit (MRC-ICU) scoring tool in critically ill patients and to correlate MRC with illness severity and patient outcomes.

Methods

This study was a single-center, retrospective observational chart review of adults admitted to the medical ICU (MICU) between November 2016 and June 2017. The primary aim was the development and internal validation of the MRC-ICU scoring tool. Secondary aims included external validation of the MRC-ICU and exploration of relationships between medication regimen complexity and patient outcomes. Exclusion criteria included a length of stay of less than 24 hours in the MICU, active transfer, or hospice orders at 24 hours. A total of 130 patient medication regimens were used to test, modify, and validate the MRC-ICU tool.

Results

The 39-line item medication regimen complexity scoring tool was validated both internally and externally. Convergent validity was confirmed with total medications (p < 0.0001). Score discriminant validity was confirmed by lack of association with age (p = 0.1039) or sex (p = 0.7829). The MRC-ICU score was significantly associated with ICU length of stay (p = 0.0166), ICU mortality (p = 0.0193), and patient acuity (p < 0.0001).

Conclusion

The MRC-ICU scoring tool was validated and found to correlate with length of stay, inpatient mortality, and patient acuity.