bluuebunny/crossref_metadata_2025 huggingface dataset:
Fresh versus Frozen Embryo Transfer in PCOS: Arguments for and Against
Authors: Wei Daimin , Chen Zi-Jiang , Ma Jinlong
Published: October 2017

In vitro fertilization (IVF) is a common infertility treatment for women with polycystic ovarian syndrome (PCOS) who have failed to conceive in ovulation induction and who have other concomitant infertility factors. Women with PCOS tend to have an excess response to ovarian stimulation during IVF. Freeze-all strategy with deferred frozen embryo transfer was initially used to prevent ovarian hyperstimulation syndrome (OHSS) in patients with a high risk. New evidence from randomized trials showed elective frozen embryo transfer in PCOS women with a low risk of OHSS could also lower the incidence of OHSS, improve live birth rate mainly by decreasing pregnancy loss, and increase birth weight of singleton infants compared with fresh embryo transfer. However, the risk of preeclampsia was higher after frozen than fresh embryo transfer. Observational studies and limited randomized trials showed the risks of other obstetric outcomes and long-term safety profile after frozen embryo transfers were at least as good as that after fresh embryo transfer. Summarily, current evidence showed elective freeze-all and frozen embryo transfer is generally superior to fresh embryo transfer to achieve live birth in women with PCOS; however, its effect on obstetric outcome and long-term outcome warrants further studies.
Prevention of multidrug-resistant infections from contaminated duodenoscopes: Position Statement of the European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastroenterology Nurses and Associates (ESGENA)
Authors: Beilenhoff Ulrike , Biering Holger , Blum Reinhard , Brljak Jadranka , Cimbro Monica , Dumonceau Jean-Marc , Hassan Cesare , Jung Michael , Neumann Christiane , Pietsch Michael , Pineau Lionel , Ponchon Thierry , Rejchrt Stanislav , Rey Jean-François , Schmidt Verona , Tillett Jayne , van Hooft Jeanin
Published: October 2017

Patients should be informed about the benefits and risks of endoscopic retrograde cholangiopancreatography (ERCP)

Only specially trained and competent personnel should carry out endoscope reprocessing.

Manufacturers of duodenoscopes should provide detailed instructions on how to use and reprocess their equipment.

In the case of modifications to their equipment, manufacturers should provide updated instructions for use.

Detailed reprocessing protocols based on the manufacturer’s instructions for use should clearly lay out the different reprocessing steps necessary for each endoscope model.

Appropriate cleaning equipment should be used for duodenoscopes in compliance with the manufacturer’s instructions for use.

Only purpose-designed, endoscope type-specific, single-use cleaning brushes should be used, to ensure optimal cleaning.

As soon as the endoscope is withdrawn from the patient, bedside cleaning should be performed, followed by leak testing, thorough manual cleaning steps, and automated reprocessing, in order to:

In addition to the leak test, visual inspection of the distal end as well as regular maintenance of duodenoscopes should be performed according to the manufacturer’s instructions for use, in order to detect any damage at an early stage.

The entire reprocessing procedure in endoscope washer-disinfectors (EWDs) should be validated according to the European and International Standard, EN ISO 15883.

Routine technical tests of EWDs should be performed according to the validation reports.

Microbiological surveillance of a proportion of the department’s endoscopes should be performed every 3 months, with the requirement that all endoscopes used in the unit are tested at least once a year.

In the case of suspected endoscopy-related infection, the relevant device (e. g., endoscope, EWD) should be taken out of service until adequate corrective actions have been taken.

Outbreaks should be managed by a multidisciplinary team, including endoscopy, hygiene, and microbiology experts, manufacturers, and regulatory bodies, according to national standards and/or laws.

In the case of suspected multidrug-resistant organism (MDRO) outbreaks, close cooperation between the endoscopy unit and the clinical health provider is essential (including infection control departments and hospital hygienists).
Multi-pulse scheme for laser-guided electrical breakdown of air
Authors: Polynkin Pavel
Published: October 2017

Channeling an extended electrical breakdown of air by a laser beam is a long-standing challenge in applied laser science. Virtually all previously reported experiments on discharge channeling by femtosecond laser beams relied on the application of a single laser pulse and have been conducted with discharge gaps of less than one meter, in which case the direct ohmic heating of the laser-generated plasma by the applied DC electric field is the dominant channeling mechanism. We report a laboratory-scale demonstration of a channeling approach that makes use of concatenated plasma filaments produced by a sequence of multiple ultrashort laser pulses. Direct ohmic heating of the guiding channel is eliminated through the introduction of large temporal delays between the individual laser pulses in the pulse sequence. We propose an extension of this scheme to channeling kilometer-scale discharges, including natural lightning. Our proposed approach alleviates the fundamental range limitations inherent to the single-pulse schemes reported previously. It can channel discharges propagating in either direction and along curved paths.
Exponential dependence of capture cross section on activation energy for interface traps in Al2O3/AlN/AlGaN/GaN metal-insulator-semiconductor heterostructures
Authors: Zhu Jiejie , Zhu Qing , Chen Lixiang , Wu Mei , Hou Bin , Yang Ling , Hao Yue , Ma Xiaohua
Published: October 2017

This paper presents a systematic study on the interface traps in AlGaN/GaN metal-insulator-semiconductor (MIS) heterostructures with an atomic layer deposited Al2O3/AlN gate stack. The interface trap density in MIS heterostructures with and without recess gate is estimated to be 2.76 × 1013 eV−1 cm−2 and 2.38 × 1013 eV−1 cm−2, respectively, by using the conductance method. The capture cross section, extracted from Arrhenius fitting, shows an exponential increase from 1.73 × 10−18 cm2 to 1.07 × 10−16 cm2 with an increase in trap activation energy from 0.21 eV to 0.47 eV for MIS heterostructures with recess gate, while the exponentially related capture cross section and activation energy for the case without recess gate are 1.19 × 10−18–2.36 × 10−12 cm2 and 0.15–0.82 eV, respectively. The voltage-dependent measurement enables different interface traps detectable which are continuously distributed within the bandgap, and the exponential dependence of the capture cross section on activation energy is attributed to the entropy change accompanying electron emission from interface traps to the conduction band. The comparison between devices with and without recess gate shows that recess etching leads to a decrease in the linear dependence factor of activation energy on gate voltage from 0.61 to 0.52 and also slightly reduces the influence of atomic vibration on electron emission.
Response to “Comment on ‘Lock-in in forced vibration of a circular cylinder’” [Phys. Fluids 29, 109101 (2017)]
Authors: Kumar Samvit , Navrose  , Mittal Sanjay
Published: October 2017

The map of the energy transfer between the fluid and structure, on the A*− f* plane, for forced vibrations at Re = 100 was presented in our earlier work. The free vibration response of the cylinder for m* = 10 and zero damping, at the same Re, was overlaid on the energy map. In this work we add free vibration data to the plot for more values of m*. This data has been recently presented by Navrose and Mittal [“The critical mass phenomenon in vortex-induced vibration at low Re,” J. Fluid Mech. 820, 159–186 (2017)] for zero structural damping and a wide range of mass ratio up to very low values of m*.
Epitaxial structure and electronic property of β-Ga2O3 films grown on MgO (100) substrates by pulsed-laser deposition
Authors: Wakabayashi Ryo , Yoshimatsu Kohei , Hattori Mai , Ohtomo Akira
Published: October 2017

We investigated heteroepitaxial growth of Si-doped Ga2O3 films on MgO (100) substrates by pulsed-laser deposition as a function of growth temperature (Tg) to find a strong correlation between the structural and electronic properties. The films were found to contain cubic γ-phase and monoclinic β-phase, the latter of which indicated rotational twin domains when grown at higher Tg. The formation of the metastable γ-phase and twin-domain structure in the stable β-phase are discussed in terms of the in-plane epitaxial relationships with a square MgO lattice, while crystallinity of the β-phase degraded monotonically with decreasing Tg. The room-temperature conductivity indicated a maximum at the middle of Tg, where the β-Ga2O3 layer was relatively highly crystalline and free from the twin-domain structure. Moreover, both crystallinity and conductivity of β-Ga2O3 films on the MgO substrates were found superior to those on α-Al2O3 (0001) substrates. A ratio of the conductivity, attained to the highest quantity on each substrate, was almost three orders of magnitude.
Effect of an annealing on magnetic properties of Fe-Ni films electroplated in citric-acid-based plating baths
Authors: Yanai T. , Koda K. , Eguchi K. , Morimura T. , Takashima K. , Nakano M. , Fukunaga H.
Published: October 2017

We have already reported Fe-Ni films with good soft magnetic properties prepared by using an electroplating method. In the present study, we employed an annealing for further improvement in soft magnetic properties of the electroplated Fe-Ni films. The annealing reduces the coercivity of the films, and the reduction rate of the coercivity depended on the Cl- ion concentration in the bath. The Fe22Ni78 films prepared in the plating bath with high Cl- ion concentration showed large reduction rate of the coercivity, and we found that the annealing is more effective for high Cl- ion concentration bath since much lower coercivity value can be obtained compared with that for low Cl- ion concentration one.
Air entrainment driven by a converging rotational field in a viscous liquid
Authors: Kumar Parmod , Das Arup K. , Mitra Sushanta K.
Published: October 2017

A thorough physical understanding of gas entrainment within a liquid pool is established using a pair of fully submerged cylinders with an opposite but symmetric rotational field. An asymmetric version of such entrainment of gaseous filaments inside a liquid has been demonstrated in our earlier work [P. Kumar, A. K. Das and S. K. Mitra, Phys. Fluids 29, 022101 (2017)]. Here, our efforts focus on revealing the governing factors and understanding the stages of alteration from a stratified to an undulating interface for a wide range of symmetric cylinder rotations. Interfacial configurations such as an upper rounded crest, a bubble-ejecting jet, and a non-collapsible jet with an air pocket in the stagnant zone are obtained as the cylinder rotation increases. Near the critical capillary number, air pinch-off into a filament and subsequent stable collapse of this filament into bubbles were observed. As the rotation-driven capillary number increased, we noted the formation of an entrained jet of gaseous-phase forming air pockets in the region, which resulted in a diverging rotational field. Our analysis of the fluid stream explains the interfacial configurations and corresponding entrainment patterns based on fundamental physics. The power-law fit (Y = KXm) of the cusp profiles revealed close agreement with numerically obtained interfaces. We propose correlation coefficients as a function of the capillary number. We also assess the dependence of the entrainment pattern on cylinder submergence and spacing.
Interactions between the first mode and the second Bragg gap in a cylindrical waveguide with undulated walls
Authors: Xue Jiu-Ling , Liu Huan , Liu Ting , Zheng Fu-Hou , Fan Ya-Xian , Tao Zhi-Yong
Published: October 2017

Bragg resonances caused by the same transverse modes can always play a major role in periodic waveguides when the period is larger than the average radius. Because of higher-order mode cutoffs, the related Bragg gaps can be identified as interactions between different spatial harmonics of the fundamental mode, and the first Bragg gaps are more intensive than the higher ones. When we alter the parameters of the periodic waveguide, especially, decrease the period, the first transverse mode can be involved in Bragg gaps. Here, we demonstrate a direct mode-stopband interaction between the first mode and the second Bragg gap, that an extraordinary passband arises in the original second Bragg gap and splits the bandgap into two. Furthermore, the extraordinary passband is mainly composed of a pure first mode, which effectively suppresses the transmission of the fundamental one. We have also investigated the influence of wall profiles on the transmission and mode purity, and have found that the defined shape factor of wall profiles is proportionally related to the width of both pass and stop bands. The results could benefit not only the understanding of wave phenomena but also the applications in mode generators, filters, and so on.
Stresses of PTT, Giesekus, and Oldroyd-B fluids in a Newtonian velocity field near the stick-slip singularity
Authors: Evans J. D. , Palhares Junior I. L. , Oishi C. M.
Published: October 2017

We characterise the stress singularity of the Oldroyd-B, Phan-Thien–Tanner (PTT), and Giesekus viscoelastic models in steady planar stick-slip flows. For both PTT and Giesekus models in the presence of a solvent viscosity, the asymptotics show that the velocity field is Newtonian dominated near to the singularity at the join of the stick and slip surfaces. Polymer stress boundary layers are present at both the stick and slip surfaces. By integrating along streamlines, we verify the polymer stress behavior of r−4/11 for PTT and r−5/16 for Giesekus, where r is the radial distance from the singularity. These asymptotic results for PTT and Giesekus do not hold in the limit of vanishing quadratic stress terms for Oldroyd-B. However, we can consider the Oldroyd-B model in the fixed kinematics of a prescribed Newtonian velocity field. In contrast to PTT and Giesekus, this is not the correct balance for the momentum equation but does allow insight into the behavior of the Oldroyd-B equations near the singularity. A three-region asymptotic structure is again apparent with now a polymer stress singularity of r−4/5. The high Weissenberg boundary layer equations are found to manifest themselves at the stick surface and are of thickness r3/2. At the slip surface, dominant balance between the upper convected stress and rate-of-strain terms gives a slip boundary layer of thickness r2. The solution of the slip boundary layer shows that the polymer stress is now singular along the slip surface. These results are supported through numerical integration along streamlines of the Oldroyd-B equations in a Newtonian velocity field. The Oldroyd-B model thus extends the point singularity at the join of the stick and slip surfaces to the whole of slip surface. As such, it does not have a physically meaningful solution in a Newtonian velocity field. We would expect a similar stress behavior for this model in the true viscoelastic velocity field.
Origin of diverse time scales in the protein hydration layer solvation dynamics: A simulation study
Authors: Mondal Sayantan , Mukherjee Saumyak , Bagchi Biman
Published: October 2017

In order to inquire the microscopic origin of observed multiple time scales in solvation dynamics, we carry out several computer experiments. We perform atomistic molecular dynamics simulations on three protein-water systems, namely, lysozyme, myoglobin, and sweet protein monellin. In these experiments, we mutate the charges of the neighbouring amino acid side chains of certain natural probes (tryptophan) and also freeze the side chain motions. In order to distinguish between different contributions, we decompose the total solvation energy response in terms of various components present in the system. This allows us to capture the interplay among different self- and cross-energy correlation terms. Freezing the protein motions removes the slowest component that results from side chain fluctuations, but a part of slowness remains. This leads to the conclusion that the slow component approximately in the 20–80 ps range arises from slow water molecules present in the hydration layer. While the more than 100 ps component has multiple origins, namely, adjacent charges in amino acid side chains, hydrogen bonded water molecules and a dynamically coupled motion between side chain and water. In addition, the charges enforce a structural ordering of nearby water molecules and helps to form a local long-lived hydrogen bonded network. Further separation of the spatial and temporal responses in solvation dynamics reveals different roles of hydration and bulk water. We find that the hydration layer water molecules are largely responsible for the slow component, whereas the initial ultrafast decay arises predominantly (approximately 80%) due to the bulk. This agrees with earlier theoretical observations. We also attempt to rationalise our results with the help of a molecular hydrodynamic theory that was developed using classical time dependent density functional theory in a semi-quantitative manner.
Thermal conductivity of electron-irradiated graphene
Authors: Weerasinghe Asanka , Ramasubramaniam Ashwin , Maroudas Dimitrios
Published: October 2017

We report results of a systematic analysis of thermal transport in electron-irradiated, including irradiation-induced amorphous, graphene sheets based on nonequilibrium molecular-dynamics simulations. We focus on the dependence of the thermal conductivity, k, of the irradiated graphene sheets on the inserted irradiation defect density, c, as well as the extent of defect passivation with hydrogen atoms. While the thermal conductivity of irradiated graphene decreases precipitously from that of pristine graphene, k0, upon introducing a low vacancy concentration, c < 1%, in the graphene lattice, further reduction of the thermal conductivity with the increasing vacancy concentration exhibits a weaker dependence on c until the amorphization threshold. Beyond the onset of amorphization, the dependence of thermal conductivity on the vacancy concentration becomes significantly weaker, and k practically reaches a plateau value. Throughout the range of c and at all hydrogenation levels examined, the correlation k = k0(1 + αc)−1 gives an excellent description of the simulation results. The value of the coefficient α captures the overall strength of the numerous phonon scattering centers in the irradiated graphene sheets, which include monovacancies, vacancy clusters, carbon ring reconstructions, disorder, and a rough nonplanar sheet morphology. Hydrogen passivation increases the value of α, but the effect becomes very minor beyond the amorphization threshold.
Effects of severe plastic deformation on the magnetic properties of terbium
Authors: Taskaev S. , Skokov K. , Khovaylo V. , Karpenkov D. , Ulyanov M. , Bataev D. , Dyakonov A. , Gutfleisch O.
Published: October 2017

We report on the magnetic and magnetocaloric properties of Terbium ribbons subjected by cold rolling. The magnetic entropy change ΔS = 8.66 J/(kg·K) and adiabatic temperature change ΔT = 4.38 K for a bulk sample of Terbium in an external magnetic field change of 1.9 T are larger by about 12% and 26% respectively, than those values of cold rolled Terbium. The changes are fully reversible and can be fully restored by an additional annealing.
Transcranial cavitation-mediated ultrasound therapy at sub-MHz frequency via temporal interference modulation
Authors: Sun Tao , Sutton Jonathan T. , Power Chanikarn , Zhang Yongzhi , Miller Eric L. , McDannold Nathan J.
Published: October 2017

Sub-megahertz transmission is not usually adopted in pre-clinical small animal experiments for focused ultrasound (FUS) brain therapy due to the large focal size. However, low frequency FUS is vital for preclinical evaluations due to the frequency-dependence of cavitation behavior. To maximize clinical relevance, a dual-aperture FUS system was designed for low-frequency (274.3 kHz) cavitation-mediated FUS therapy. Combining two spherically curved transducers provides significantly improved focusing in the axial direction while yielding an interference pattern with strong side lobes, leading to inhomogeneously distributed cavitation activities. By operating the two transducers at slightly offset frequencies to modulate this interference pattern over the period of sonication, the acoustic energy was redistributed and resulted in a spatially homogenous treatment profile. Simulation and pressure field measurements in water were performed to assess the beam profiles. In addition, the system performance was demonstrated in vivo in rats via drug delivery through microbubble-mediated blood-brain barrier disruption. This design resulted in a homogenous treatment profile that was fully contained within the rat brain at a clinically relevant acoustic frequency.
Dispersion relations for low-frequency waves in a warm, underdense, two-fluid plasma
Authors: Kakuwa Jun
Published: October 2017

Analytical forms of dispersion relations for three lower-frequency waves in a two-fluid plasma are presented. In underdense plasmas, ωp2≲Ωce2, that is, low density or strongly magnetized plasmas, where ωp and Ωce are respectively the plasma frequency and the electron cyclotron frequency, the displacement current can become important in higher-frequency (non-magnetohydrodynamic) region. Focusing on only three branches that become magnetohydrodynamic waves in the low-frequency limit, we derive dispersion relations applicable to both underdense and overdense plasmas by the full set of equations of two-fluid plasmas including the displacement current. It is shown that our analytical results well agree with the exact numerical ones in all frequency ranges when the following conditions are satisfied: normal (i.e., not pair) plasma; low plasma β, and not extremely small electron to ion temperature ratio, me/mi≪Te/Ti, while more exact dispersion relations are needed to perform polarization analysis.
Effects of finite-size neutrally buoyant particles on the turbulent flows in a square duct
Authors: Lin Zhaowu , Yu Zhaosheng , Shao Xueming , Wang Lian-Ping
Published: October 2017

Interface-resolved direct numerical simulations of the particle-laden turbulent flows in a square duct are performed with a direct-forcing fictitious domain method. The effects of the finite-size particles on the mean and root-mean-square (RMS) velocities are investigated at the friction Reynolds number of 150 (based on the friction velocity and half duct width) and the particle volume fractions ranging from 0.78% to 7.07%. Our results show that the mean secondary flow is enhanced and its circulation center shifts closer to the center of the duct cross section when the particles are added. The reason for the particle effect on the mean secondary flow is analyzed by examining the terms in the mean streamwise vorticity equation. It is observed that the particles enhance the gradients of the secondary Reynolds normal stress difference and shear stress in the near-wall region near the corners, which we think is mainly responsible for the enhancement in the mean secondary flow. Under a prescribed driving pressure gradient, the presence of particles attenuates the bulk velocity and the turbulent intensity. All particle-induced effects are intensified with increasing particle volume fraction and decreasing particle size, if other parameters are fixed. In addition, the particles accumulate preferentially in the near-corner region. The effects of the type of the collision model (i.e., if friction and damping are included or not) on the results are found significant, but not so significant to bring about qualitatively different results.
Tailoring magnetostriction with various directions for directional solidification Fe82Ga15Al3 alloy by magnetic field heat treatment
Authors: Li Xiaolong , Bao Xiaoqian , Liu Yangyang , Yu Linhua , Li Jiheng , Gao Xuexu
Published: October 2017

The magnetostriction of the Fe82Ga15Al3 alloy, along the length and width, can be tailored by applying a magnetic field heat treatment. In this work, the Fe82Ga15Al3 sheet was cut from the directional solidified Fe82Ga15Al3 alloy with the ⟨100⟩ preferred orientation and was annealed at 720 °C for 30 min under a magnetic field of 800 Oe along the length direction with a heating and cooling rate of 100 °C/min. The magnetostrictive properties along the length and width directions were modified to λ// = 7 ppm and λ⊥ = −210 ppm from λ// = 210 ppm and λ⊥ = −10 ppm for the initial sample prior to the magnetic field heat treatment. The cellular-like magnetic domain structure was composed of parallel 180° stripe domains and vertical 90° domains observed using a magnetic-force microscope. The change in magnetostriction along parallel and perpendicular directions was mainly resulted from the rotation of the magnetic domain units.
The opposing effects of isotropic and anisotropic attraction on association kinetics of proteins and colloids
Authors: Newton Arthur C. , Kools Ramses , Swenson David W. H. , Bolhuis Peter G.
Published: October 2017

The association and dissociation of particles via specific anisotropic interactions is a fundamental process, both in biology (proteins) and in soft matter (colloidal patchy particles). The presence of alternative binding sites can lead to multiple productive states and also to non-productive “decoy” or intermediate states. Besides anisotropic interactions, particles can experience non-specific isotropic interactions. We employ single replica transition interface sampling to investigate how adding a non-productive binding site or a nonspecific isotropic interaction alters the dimerization kinetics of a generic patchy particle model. The addition of a decoy binding site reduces the association rate constant, independent of the site’s position, while adding an isotropic interaction increases it due to an increased rebinding probability. Surprisingly, the association kinetics becomes non-monotonic for a tetramer complex formed by multivalent patchy particles. While seemingly identical to two-particle binding with a decoy state, the cooperativity of binding multiple particles leads to a kinetic optimum. Our results are relevant for the understanding and modeling of biochemical networks and self-assembly processes.
Interactions and collisions of topological solitons in a semiconductor laser with optical injection and feedback
Authors: Garbin B. , Javaloyes J. , Barland S. , Tissoni G.
Published: October 2017

We present experimental and numerical results about dynamical interactions of topological solitons in a semiconductor laser with coherent injection and feedback. We show different kind of interactions such as repulsion, annihilation, or formation of soliton bound states, depending on laser parameters. Collisions between single structures and bound states conserve momentum and charge.
A wrinkling-based method for investigating glassy polymer film relaxation as a function of film thickness and temperature
Authors: Chung Jun Young , Douglas Jack F. , Stafford Christopher M.
Published: October 2017

We investigate the relaxation dynamics of thin polymer films at temperatures below the bulk glass transition Tg by first compressing polystyrene films supported on a polydimethylsiloxane substrate to create wrinkling patterns and then observing the slow relaxation of the wrinkled films back to their final equilibrium flat state by small angle light scattering. As with recent relaxation measurements on thin glassy films reported by Fakhraai and co-workers, we find the relaxation time of our wrinkled films to be strongly dependent on film thickness below an onset thickness on the order of 100 nm. By varying the temperature between room temperature and Tg (≈100 °C), we find that the relaxation time follows an Arrhenius-type temperature dependence to a good approximation at all film thicknesses investigated, where both the activation energy and the relaxation time pre-factor depend appreciably on film thickness. The wrinkling relaxation curves tend to cross at a common temperature somewhat below Tg, indicating an entropy-enthalpy compensation relation between the activation free energy parameters. This compensation effect has also been observed recently in simulated supported polymer films in the high temperature Arrhenius relaxation regime rather than the glassy state. In addition, we find that the film stress relaxation function, as well as the height of the wrinkle ridges, follows a stretched exponential time dependence and the short-time effective Young’s modulus derived from our modeling decreases sigmoidally with increasing temperature—both characteristic features of glassy materials. The relatively facile nature of the wrinkling-based measurements in comparison to other film relaxation measurements makes our method attractive for practical materials development, as well as fundamental studies of glass formation.
Compact Rb optical frequency standard with 10−15 stability
Authors: Zhang Shengnan , Zhang Xiaogang , Cui Jingzhong , Jiang Zhaojie , Shang Haosen , Zhu Chuanwen , Chang Pengyuan , Zhang Ling , Tu Jianhui , Chen Jingbiao
Published: October 2017

We achieved a low-cost and small-sized Rb optical frequency standard based on 85Rb 5S1/2 → 6P3/2 transition with 10−15 stability, which is comparable with that of the best 532 nm I2 optical frequency standards. In this system, we directly lock the 420 nm diode laser on the 5S1/2 F = 3 → 6P3/2 F′ = 4 hyperfine transition line without an additional Pound-Drever-Hall pre-locking system. The signal-to-noise-ratio reaches as high as 350 000 when the averaging time is at 1 s. Eventually by the fluctuation of the residual error signal after locking, the preliminary stability of the optical frequency standard reaches 1.2×10−14/τ, decreasing to 2.1 × 10−15 at 80 s. It shows potential in stability performance, experimental cost, and system volume compared with the 532 nm I2 optical frequency standard as a wavelength standard. It also opens a door for the achievement of wavelength standards by using higher excited states of alkalies.
Deconstructing the 4-h rule for access to emergency care and putting patients first
Authors: Scott Ian , Sullivan Clair , Staib Andrew , Bell Anthony
Published: October 2017

Evidence suggests improved outcomes for patients requiring emergency admission to hospital are associated with improved emergency department (ED) efficiency and lower transit times. Factors preventing timely transfers of emergency patients to in-patient beds across the ED–in-patient interface are major causes for ED crowding, for which several remedial strategies are possible, including parallel processing of probable admissions, direct-to-ward admissions and single-point medical registrars for receiving and processing all referrals directed at specific speciality units. Dynamic measures of ED overcrowding that focus on boarding time are more indicative of EDs with exit block involving the ED–in-patient interface than static proxy measures such as hospital bed occupancy and numbers of ED presentations. The ideal 4-h compliance rate for all ED presentations is around 80%, based on a large retrospective study of more than 18million presentations to EDs of 59 Australian hospitals over 4 years, which demonstrated a highly significant linear reduction in risk-adjusted in-patient mortality for admitted patients as the compliance rate for all patients rose to 83%, but was not confirmed beyond this rate. Closely monitoring patient outcomes for emergency admissions in addition to compliance with time-based access targets is strongly recommended in ensuring reforms aimed at decongesting EDs do not compromise the quality and safety of patient care.
Chemical transferability of functional groups follows from the nearsightedness of electronic matter
Authors: Fias Stijn , Heidar-Zadeh Farnaz , Geerlings Paul , Ayers Paul W.
Published: October 2017

Significance

The empirically observed transferability of functional groups is shown to follow from Kohn’s nearsightedness principle for electron density. To show this, we analytically calculated and analyzed the softness kernel for molecules. The relevance of this work touches on physics (the nearsightedness principle), molecular chemistry and materials science (chemical transferability and similarity), and computer science (machine-learning approaches for pharmaceutical and materials design).
Gut dysbiosis breaks immunological tolerance toward the central nervous system during young adulthood
Authors: Yadav Sudhir K. , Boppana Sridhar , Ito Naoko , Mindur John E. , Mathay Martin T. , Patel Ankoor , Dhib-Jalbut Suhayl , Ito Kouichi
Published: October 2017

Significance

Multiple sclerosis (MS) is classified as an autoimmune disease of the central nervous system (CNS). Alterations of gut microbiota (gut dysbiosis) are frequently observed in MS patients. It is still unknown how gut dysbiosis contributes to development of MS. We report here that gut dysbiosis, which we attribute to expansion of enteric pathogenic bacteria, triggers and/or exacerbates the spontaneous development of experimental autoimmune encephalomyelitis, an animal model of MS. This occurs during the period of young adulthood by reducing development of Foxp3
+
Treg cells and expression of E3 ubiquitin ligase genes involved in protection from autoimmune diseases. This study suggests that gut dysbiosis may play a pathological role in the initiation and/or progression of MS during a defined age window.
Ligand-induced conformational dynamics of the
Escherichia coli
Na
+
/H
+
antiporter NhaA revealed by hydrogen/deuterium exchange mass spectrometry
Authors: Eisinger Martin Lorenz , Dörrbaum Aline Ricarda , Michel Hartmut , Padan Etana , Langer Julian David
Published: October 2017

Significance

Sodium ion/proton antiporters exchange sodium ions against protons across the membrane and are thereby essential for ion homeostasis inside living cells. The bacterial sodium ion/proton antiporter NhaA is the most important working model for this class of proteins. However, the structure of NhaA has only been determined at low pH where it is inactive. Nonetheless, different models were proposed for the mechanism of antiport. Here, we analyzed the conformational changes of unmodified NhaA upon ligand binding at physiological pH. We utilized hydrogen/deuterium exchange mass spectrometry to monitor conformational changes of the entire protein. We observed that, upon ligand binding, NhaA undergoes a conformational change consisting of two movements, and propose a model that reconciles apparently conflicting data in the field.
Rad52 phosphorylation by Ipl1 and Mps1 contributes to Mps1 kinetochore localization and spindle assembly checkpoint regulation
Authors: Lim Gyubum , Huh Won-Ki
Published: October 2017

Significance

Rad52 is a well-known factor in homologous recombination. In this study, we discover functions of Rad52 in spindle assembly checkpoint (SAC) regulation and Mps1 localization for chromosome biorientation. Deletion of
RAD52
leads to various phenotypes of inaccurate chromosome segregation that are not observed in another homologous recombination-defective
rad51
Δ mutant. Furthermore, we find that Rad52 is a substrate of mitotic kinases Ipl1/Aurora and Mps1 and that Rad52 phosphorylation by Ipl1 and Mps1 contributes to Mps1 kinetochore localization and SAC regulation. From these findings, we suggest that Rad52 functions as a mediator between Ipl1 and Mps1 in the regulatory pathway of mitosis. Our results provide detailed insights into the molecular basis of chromosome segregation and SAC regulation.
PAF1 complex component Leo1 helps recruit
Drosophila
Myc to promoters
Authors: Gerlach Jennifer M. , Furrer Michael , Gallant Maria , Birkel Dirk , Baluapuri Apoorva , Wolf Elmar , Gallant Peter
Published: October 2017

Significance

We identify the PAF1 complex component Leo1 as a factor that helps recruit Myc to its target genes. In particular when Myc is overexpressed, Leo1 becomes limiting for transcriptional regulation by Myc.
Early rearing history influences oxytocin receptor epigenetic regulation in rhesus macaques
Authors: Baker Maggie , Lindell Stephen G. , Driscoll Carlos A. , Zhou Zhifeng , Yuan Qiaoping , Schwandt Melanie L. , Miller-Crews Isaac , Simpson Elizabeth A. , Paukner Annika , Ferrari Pier Francesco , Sindhu Ravi Kumar , Razaqyar Muslima , Sommer Wolfgang H. , Lopez Juan F. , Thompson Robert C. , Goldman David , Heilig Markus , Higley J. Dee , Suomi Stephen J. , Barr Christina S.
Published: October 2017

Significance

Epigenetically programmed stress adaptation may be a conduit for informing offspring of environmental challenge. We employed ChIP-sequencing to examine effects of early environment on epigenetic regulation using hippocampal samples from macaques exposed to disruption in maternal care. We found decreased H3K4me3 binding at genes critical to behavioral stress response, the most robust being the oxytocin receptor gene (
OXTR
), for which we observed a corresponding decrease in RNA expression. Post hoc analysis showed that a gain-of-function
OXTR
SNP rescued behavioral differences in early stress-exposed subjects. Our data suggest that epigenetic down-modulation of
OXTR
in brain could contribute to behavioral differences observed in early stress-exposed subjects and that functional genetic variation plays a role. These could have translational implications for human psychiatric disease and personality disorders.
Structures of Qβ virions, virus-like particles, and the Qβ–MurA complex reveal internal coat proteins and the mechanism of host lysis
Authors: Cui Zhicheng , Gorzelnik Karl V. , Chang Jeng-Yih , Langlais Carrie , Jakana Joanita , Young Ry , Zhang Junjie
Published: October 2017

Significance

Host lysis and virion assembly are essential processes during the infection cycle of single-stranded RNA (ssRNA) viruses. Using single-particle cryoelectron microscopy, we visualized how the ssRNA virus, Qβ, uses its single-molecule “tail protein,” A
2
, to inhibit MurA, a bacterial enzyme essential for cell wall biosynthesis, leading to lysis of the host cell. We also revealed an extra coat protein dimer, which instead of being a part of the viral capsid, is sequestered within the virion, binding to an RNA hairpin from a five-way junction in the genomic RNA. The same five-way junction also presents hairpins to bind A
2
and other coat protein dimers in the capsid, potentially supporting a nucleation event for virion assembly.
Widespread covariation of early environmental exposures and trait-associated polygenic variation
Authors: Krapohl E. , Hannigan L. J. , Pingault J.-B. , Patel H. , Kadeva N. , Curtis C. , Breen G. , Newhouse S. J. , Eley T. C. , O’Reilly P. F. , Plomin R.
Published: October 2017

Significance

Environmental exposures are among the best predictors of health and educational outcomes. Models that estimate the effect of environmental exposures on developmental outcomes typically ignore genetic factors or focus on gene–environment interaction (whether individuals’ response to environmental exposures depends on their genotype). Here we test gene–environment correlation (whether individuals’ exposure to environments depends on their genotype). Using a method that tests specific genetic effects while controlling for background genetic effects, we estimate covariation between children’s genetic liability/propensity for core developmental outcomes and a wide range of environmental exposures. Findings suggest that genetic variants associated with traits, such as educational attainment, body mass index, and schizophrenia, also capture environmental risk and protective factors.
Speed of the bacterial flagellar motor near zero load depends on the number of stator units
Authors: Nord Ashley L. , Sowa Yoshiyuki , Steel Bradley C. , Lo Chien-Jung , Berry Richard M.
Published: October 2017

Significance

The bacterial flagellar motor is a rotary molecular motor responsible for swimming, swarming, and chemotaxis in many species of bacteria. It generates torque by interactions between a rotor 50 nm in diameter and multiple stator units. We overturn the prevailing understanding of how stator units interact with each other by showing that motor speed is dependent on the number of stator units even at high speed near zero torque. We describe a method to measure torque and speed that uses synthetic hybrid stators driven by different ion types and show that, with simple rescaling, a single torque–speed curve describes the motor over widely varying values of the membrane voltage, driving ion type and ionic chemical potential gradient.
Importance of a species’ socioecology: Wolves outperform dogs in a conspecific cooperation task
Authors: Marshall-Pescini Sarah , Schwarz Jonas F. L. , Kostelnik Inga , Virányi Zsófia , Range Friederike
Published: October 2017

Significance

A popular hypothesis is that during the course of domestication, dogs acquired a tamer temperament, showing increased tolerance and cooperative inclinations compared with their wolf relatives. This “domestication effect” is suggested to mirror how humans evolved a more tolerant and cooperative nature compared with chimpanzees. However, whereas wolves rely heavily on cooperation for hunting, pup-rearing, and territorial defense, dogs’ reliance on cooperation is much reduced. Here we compared similarly raised and kept wolves and dogs on a cooperative string-pulling task and found that, in line with the different socioecology of the two species, wolves better cooperate with their conspecifics than dogs. Furthermore, cooperation in wolves was more successful among partners of similar rank and with a close social bond.
Mutagenic cost of ribonucleotides in bacterial DNA
Authors: Schroeder Jeremy W. , Randall Justin R. , Hirst William G. , O’Donnell Michael E. , Simmons Lyle A.
Published: October 2017

Significance

DNA polymerases frequently incorporate ribonucleotides in place of deoxyribonucleotides during genome replication. RNase HII is responsible for initiating the removal of ribonucleotide errors across all three domains of life. Ribonucleotides that persist in genomic DNA due to defects in RNase HII result in strand breaks, mutagenesis, and neurodevelopmental disease in humans. Here, we define the proteins important for ribonucleotide excision repair in
Bacillus subtilis
and use genome-wide mutational profiling to determine the mutagenic cost of ribonucleotides in RNase HII-deficient cells. We show that the absence of RNase HII yields error-prone ribonucleotide correction via a pathway that relies on an essential DNA polymerase. We further demonstrate that error-prone ribonucleotide removal causes sequence context-dependent GC → AT transitions on the lagging strand.
Cliff-edge model predicts intergenerational predisposition to dystocia and Caesarean delivery
Authors: Mitteroecker Philipp , Windhager Sonja , Pavlicev Mihaela
Published: October 2017

Significance

The cliff-edge model explains the evolutionary persistence of relatively high incidences of fetopelvic disproportion (FPD), the mismatch of fetal and maternal dimensions during human childbirth. It also predicts that FPD rates have increased evolutionarily since the regular use of Caesarean sections. Here we show that the model also explains why women born by Caesarean because of FPD are about twice as likely to develop FPD in their own childbirth compared with women born vaginally. This theoretical prediction of a complex epidemiological pattern lends support to the cliff-edge model and its underlying assumptions.
Vibrational coupling in plasmonic molecules
Authors: Yi Chongyue , Dongare Pratiksha D. , Su Man-Nung , Wang Wenxiao , Chakraborty Debadi , Wen Fangfang , Chang Wei-Shun , Sader John E. , Nordlander Peter , Halas Naomi J. , Link Stephan
Published: October 2017

Significance

In this work, we provide evidence of vibrational coupling between the constituent atoms in a plasmonic molecule mediated by coherent substrate phonons. A simple coupled harmonic oscillator model provides fundamental insight into the optomechanical selection rules for the launching of vibrational modes. The coupling strength-dependent vibrational frequency shifts can be directly manipulated by precise tuning of the structure of the plasmonic molecule by using top-down lithography. This tunability paves the way for new strategies to design optomechanical devices based on metallic nanostructures.
Mib1 contributes to persistent directional cell migration by regulating the Ctnnd1-Rac1 pathway
Authors: Mizoguchi Takamasa , Ikeda Shoko , Watanabe Saori , Sugawara Michiko , Itoh Motoyuki
Published: October 2017

Significance

Cell migration is involved in various biological processes, including animal development and cancer metastasis. Cells show either of two different types of migratory behavior: random or directional. We show that defects in mind bomb 1 (Mib1) ubiquitin ligase, an enzyme that adds ubiquitin to substrates, leads to an increase in random cell migration. Our study revealed that Mib1 ubiquitinates Ctnnd1, a positive regulator of the small GTPase Rac1, in cultured cells. We further found that Mib1-dependent Ctnnd1 ubiquitination decreases Ctnnd1-mediated activation of Rac1, which increases random cell migration, in cultured cells. Therefore, this study shows that Mib1 contributes to persistent directional cell migration, at least in part, by regulating the Ctnnd1–Rac1 pathway.
CREB coactivators CRTC2 and CRTC3 modulate bone marrow hematopoiesis
Authors: Kim Jeong-Ho , Hedrick Susan , Tsai Wen-Wei , Wiater Ezra , Le Lay John , Kaestner Klaus H. , Leblanc Mathias , Loar Andrew , Montminy Marc
Published: October 2017

Significance

The second messenger cAMP mediates the salutary effects of prostaglandin E2 on hematopoietic stem cell (HSC) engraftment in bone marrow (BM). We found that disruption of the cAMP-inducible coactivators CRTC2 and CRTC3 in BM stromal cells promotes neutrophilia and HSC egress due to up-regulation of granulocyte colony-stimulating factor (G-CSF). CRTC2/3 were found to reduce G-CSF expression by inhibiting signaling through the transcription factor STAT3. These results demonstrate how cross-talk between cAMP and cytokine signaling pathways contributes to BM homeostasis.
Construing negotiation
Authors: Yau-ni Wan Jenny
Published: October 2017

The call centre conversation is a telephonic exchange of voices between the customer and the customer service representative (CSR). Both lexicogrammatical and prosodic features are used to construe emotional and attitudinal recognition. Studying these features can investigate how the call centre discourse is construed, and how the interpersonal meaning takes shape through the text. The spoken data are constructed by Filipino CSRs and American English-speaking customers. The findings show that participants tend to make specific paralinguistic voice quality choices to express their emotions in dialogue. This article first discusses the voice quality framework for its semiotic features in relation to interpersonal meaning, reviews previous voice quality studies and later delineates how voice quality relates to interpersonal meaning in the calls.