bluuebunny/crossref_metadata_2025 huggingface dataset:
Enabling complete multichannel nonadiabatic dynamics: A global representation of the two-channel coupled, 1,21A and 13A states of NH3 using neural networks
Authors: Wang Yuchen , Guan Yafu , Guo Hua , Yarkony David R.
Published: March 2021

Global coupled three-state two-channel potential energy and property/interaction (dipole and spin–orbit coupling) surfaces for the dissociation of NH3(Ã) into NH + H2 and NH2 + H are reported. The permutational invariant polynomial-neural network approach is used to simultaneously fit and diabatize the electronic Hamiltonian by fitting the energies, energy gradients, and derivative couplings of the two coupled lowest-lying singlet states as well as fitting the energy and energy gradients of the lowest-lying triplet state. The key issue in fitting property matrix elements in the diabatic basis is that the diabatic surfaces must be smooth, that is, the diabatization must remove spikes in the original adiabatic property surfaces attributable to the switch of electronic wavefunctions at the conical intersection seam. Here, we employ the fit potential energy matrix to transform properties in the adiabatic representation to a quasi-diabatic representation and remove the discontinuity near the conical intersection seam. The property matrix elements can then be fit with smooth neural network functions. The coupled potential energy surfaces along with the dipole and spin–orbit coupling surfaces will enable more accurate and complete treatment of optical transitions, as well as nonadiabatic internal conversion and intersystem crossing.
Polar diatomic molecules in optical cavities: Photon scaling, rotational effects, and comparison with classical fields
Authors: Triana Johan F. , Sanz-Vicario José Luis
Published: March 2021

We address topics related to molecules coupled to quantum radiation. The formalism of light–matter interaction is different for classical and quantum fields, but some analogies remain, such as the formation of light induced crossings. We show that under particular circumstances, the molecular dynamics under quantum or classical fields produce similar results, as long as the radiation is prepared as a Fock state and far from ultra-strong coupling regimes. At this point, the choice of specific initial Fock states is irrelevant since the dynamics scales. However, in realistic multistate molecular systems, radiative scaling may fail due to the presence of simultaneous efficient non-radiative couplings in the dynamics. Polar molecules have permanent dipoles, and within the context of the full quantum Rabi model with a Pauli–Fierz Hamiltonian, they play a crucial role in the polaritonic dynamics since both permanent dipole moments and self-energy terms produce drastic changes on the undressed potential energy surfaces at high coupling strengths. We also gauge the effect of including rotational degrees of freedom in cavity molecular photodynamics. For diatomic molecules, the addition of rotation amounts to transform (both with classical or quantum fields) a light induced crossing into a light induced conical intersection. However, we show that conical intersections due to molecular rotation do not represent the standard properties of well-known efficient intrinsic conical intersections inasmuch they do not enhance the quantum transition rates.
Numerical investigations of head-on collisions of binary unequal-sized droplets on superhydrophobic walls
Authors: Cheng Yongpan , Li Jiwei , Xu Jinliang , Shen Yang
Published: March 2021

Droplet head-on impact is widely encountered in nature, industry, and agricultural applications. In our study, a two-dimensional axisymmetric model, using the volume-of-fluid method, is built to simulate unequally sized droplet head-on impact on a superhydrophobic surface. The collision regime, after droplet coalescence, is obtained with dimensionless parameters, as well as the contact time, maximum spreading diameter, restitution coefficient, and viscous dissipation. When the impact droplet is larger than the stationary droplet on the substrate, the merged droplet can easily jump up. At high Bond numbers (Bo) or high Ohnesorge numbers (Oh), the merged droplet cannot jump up due to significant gravitational effects or viscous effects, respectively. The energy for droplet jumping mainly comes from the released surface energy after the coalescence of father and mother droplets. The contact time of a droplet with the superhydrophobic substrate is proportional to the Weber number to the 0.5th power (We0.5), and the maximum spreading diameter of a merged droplet is proportional to We0.2. With an increasing size ratio of the father droplet to the mother droplet, both the contact time and maximum spreading diameter increase. These findings will help gain insights into the dynamics of droplet head-on impact.
Experimental study of uni- and bi-directional exchange flows in a large-scale rotating trapezoidal channel
Authors: De Falco Maria Chiara , Adduce Claudia , Cuthbertson Alan , Negretti Maria Eletta , Laanearu Janek , Malcangio Daniela , Sommeria Joel
Published: March 2021

A large-scale experimental study has been conducted at the Coriolis Rotating Platform to investigate the dynamics of uni- and bi-directional exchange flows along a channel with a trapezoidal cross section under the influence of background rotation. High-resolution two-dimensional particle image velocimetry and micro-conductivity probes were used to obtain detailed velocity fields and density profiles of the exchange flow generated across the channel under different parametric conditions. Experimental measurements give new insight into the stratified-flow dynamics dependence on the magnitude of Burger number, defined as the ratio of the Rossby radius to the channel width, such that values lower than 0.5 characterize unsteady exchange flows. The measurements highlight the role that both ambient rotation and net-barotropic forcing have on the geostrophic adjustment of the dense outflowing layer and on the corresponding counter-flowing water layer fluxes. The coupled effect of these two parametric conditions largely affects the transverse velocity distribution and, for the largest net-barotropic flow in the upper fresh water layer, leads to the partial blockage of the lower saline outflow. Moreover, an increase in the mixing layer thickness, associated with larger rotation rates, and due the interface dynamics, is observed, with shear-driven interfacial instabilities analyzed to highlight the influence of both ambient rotation and net-barotropic forcing.
Measurements of laser-imprint-induced shock velocity nonuniformities in plastic targets with the Nike KrF laser
Authors: Oh Jaechul , Schmitt Andrew J. , Karasik Max , Obenschain Stephen P.
Published: March 2021

We report results of direct-drive laser imprint experiments measuring velocity perturbation profiles of shock waves produced by the Nike krypton fluoride laser. A new high-resolution two-dimensional velocimeter system was successfully implemented on the Nike laser facility and used for sensitive optical measurements of the velocity perturbations. Planar polystyrene targets with and without a thin high-Z overcoat (400 Å Au or 600 Å Pd) were irradiated by four, eight, and sixteen Nike laser beams to examine laser imprint and its mitigation. The results from the uncoated targets showed that the shock velocity perturbations decreased with an increasing number of laser beams overlapped on target, precisely as anticipated by the beam averaging effect on laser imprint. In the experiment on the shocks driven in the high-Z coated targets, the shock velocity perturbations were further reduced by a factor of 2–6 compared to their counterparts in the uncoated experiment, with the amplitude of the velocity fluctuations measured as small as 20 m/s rms for shock velocities of 20 km/s. These experiments allowed more direct measurements of laser imprint effects without relying on the Rayleigh–Taylor hydrodynamic amplification, providing valuable quantitative data for calibrating radiation-hydrodynamic simulations of laser imprint.
Mathematical constraints on the scaling exponents in the inertial range of fluid turbulence
Authors: Djenidi L. , Antonia R. A. , Tang S. L.
Published: March 2021

The dominant view in the theory of fluid turbulence assumes that, once the effect of the Reynolds number is negligible, moments of order n of the longitudinal velocity increment, (δu), can be described by a simple power-law rζn, where the scaling exponent ζn depends on n and, except for ζ3(=1), needs to be determined. In this Letter, we show that applying Hölder's inequality to the power-law form (δu)n¯∼(rL)ζn (with r/L⪡1; L is an integral length scale) leads to the following mathematical constraint: ζ2p=pζ2. When we further apply the Cauchy–Schwarz inequality, a particular case of Hölder's inequality, to |(δu)3¯| with ζ3=1, we obtain the following constraint: ζ2≤2/3. Finally, when Hölder's inequality is also applied to the power-law form (|δu|)n¯∼(rL)ζn (this form is often used in the extended self-similarity analysis) while assuming ζ3=1, it leads to ζ2=2/3. The present results show that the scaling exponents predicted by the 1941 theory of Kolmogorov in the limit of infinitely large Reynolds number comply with Hölder's inequality. On the other hand, scaling exponents, except for ζ3, predicted by current small-scale intermittency models do not comply with Hölder's inequality, most probably because they were estimated in finite Reynolds number turbulence. The results reported in this Letter should guide the development of new theoretical and modeling approaches so that they are consistent with the constraints imposed by Hölder's inequality.
Temperature dependent onset of shear thinning in supercooled glass-forming network liquids
Authors: Zhu W. , Xia Y. , Aitken B. G. , Sen S.
Published: March 2021

The onset of shear thinning and the transition from Newtonian to non-Newtonian behavior in the viscous flow of select chalcogenide and oxide network glass-forming liquids in the deeply supercooled regime and its temperature dependence are studied using parallel plate rheometry. In all cases, the onset occurs at a shear rate γ̇c that is several orders of magnitude lower than the shear relaxation rate τ0−1 and the former increases with increasing temperature. These results are in good qualitative agreement with the predictions of the existing models of shear relaxation and shear thinning based on the nonlinear Langevin equation theory, random first order transition theory, and the free volume model. However, in contrast to the theoretical predictions, the reduced shear rate W0 (=τ0γ̇c) at the onset is found to range between 10−3 and 10−5 and decrease with increasing temperature. This temperature dependence becomes stronger with increasing fragility of the liquid. These results likely indicate that the shear thinning mechanism in network liquids could be fundamentally different from those in molecular, metallic, or polymeric glass-formers.
Mechanisms of entrainment in a turbulent boundary layer
Authors: Jahanbakhshi Reza
Published: March 2021

Data from direct numerical simulation of a zero-pressure-gradient incompressible turbulent boundary layer (TBL) [You and Zaki, “Conditional statistics and flow structures in turbulent boundary layers buffeted by free-stream disturbances,” J. Fluid Mech. 866, 526 (2019)] are analyzed to examine the entrainment process. The two mechanisms by which the outer irrotational flow can be entrained into the turbulent region and their relative contribution to the growth of the spatially developing boundary layer are evaluated: (i) nibbling is the enstrophy transport across the turbulent/non-turbulent interface (TNTI), and (ii) engulfment is the entrapment of pockets of irrotational flow inside the TBL prior to finally breaking apart. The relative importance of the two mechanisms depends on the normalized vorticity threshold adopted to identify the TNTI. Our choice of this threshold highlights the structure of the TNTI and entrainment within this layer by engulfment of irrotational pockets. The sizes of the engulfed pockets are of the same order as the heads of the hairpin vortices underneath the TNTI. The vortices straddle larger streaky structures of internal layers and cause handle shaped deformations on the TNTI, which leads to engulfment as they fold onto themselves and entrap the external potential flow. Three dynamical regions are distinguished: a TNTI region (interface layer), an adjustment region, and the turbulent core. The first of these is further sub-divided into a viscous superlayer and a turbulent sublayer. It is shown as the irrotational fluid elements cross the interface layer toward the turbulent core, a smooth transition from the non-focal topology to the well-known primarily focal topology of fully developed turbulence occur. The viscous superlayer is similar to previously studied flow configurations, such as jets and mixing layers. In contrast, vorticity stretching in the turbulent sublayer is significantly weaker in the boundary layer relative to free-shear flows, which results in a smaller rate of entrainment by nibbling.
Incoherent Thomson scattering system for PHAse space MApping (PHASMA) experiment
Authors: Shi Peiyun , Srivastav Prabhakar , Beatty Cuyler , Nirwan Ripudaman Singh , Scime Earl E.
Published: March 2021

A new incoherent Thomson scattering system measures the evolution of electron velocity distribution functions perpendicular and parallel to the ambient magnetic field during kinking of a single flux rope and merging of two flux ropes through magnetic reconnection. The Thomson scattering system provides sub-millimeter spatial resolution, sufficient to diagnose the several millimeters sized magnetic reconnection electron diffusion region in the PHAse Space MAppgin experiment. Due to the relatively modest plasma density ∼1019 m−3 and electron temperature ∼1 eV, stray light suppression is critical for these measurements. Two volume Bragg gratings are used in series as a notch filter with a spectral bandwidth <0.1 nm in the collection branch. A CCD with a Gen III intensifier with peak quantum efficiency >47% is used as the detector in a 1.3 m spectrometer. Preliminary results of gun plasma electron temperature will be reported and compared with measurements obtained from a triple Langmuir probe.
Dynamics of water confined in mesopores with variable surface interaction
Authors: Jani Aîcha , Busch Mark , Mietner J. Benedikt , Ollivier Jacques , Appel Markus , Frick Bernhard , Zanotti Jean-Marc , Ghoufi Aziz , Huber Patrick , Fröba Michael , Morineau Denis
Published: March 2021

We have investigated the dynamics of liquid water confined in mesostructured porous silica (MCM-41) and periodic mesoporous organosilicas (PMOs) by incoherent quasielastic neutron scattering experiments. The effect of tuning the water/surface interaction from hydrophilic to more hydrophobic on the water mobility, while keeping the pore size in the range 3.5 nm–4.1 nm, was assessed from the comparative study of three PMOs comprising different organic bridging units and the purely siliceous MCM-41 case. An extended dynamical range was achieved by combining time-of-flight (IN5B) and backscattering (IN16B) quasielastic neutron spectrometers providing complementary energy resolutions. Liquid water was studied at regularly spaced temperatures ranging from 300 K to 243 K. In all systems, the molecular dynamics could be described consistently by the combination of two independent motions resulting from fast local motion around the average molecule position and the confined translational jump diffusion of its center of mass. All the molecules performed local relaxations, whereas the translational motion of a fraction of molecules was frozen on the experimental timescale. This study provides a comprehensive microscopic view on the dynamics of liquid water confined in mesopores, with distinct surface chemistries, in terms of non-mobile/mobile fraction, self-diffusion coefficient, residence time, confining radius, local relaxation time, and their temperature dependence. Importantly, it demonstrates that the strength of the water/surface interaction determines the long-time tail of the dynamics, which we attributed to the translational diffusion of interfacial molecules, while the water dynamics in the pore center is barely affected by the interface hydrophilicity.
Nonlinear dust acoustic perturbations within dusty plasma over sunlit lunar surface
Authors: Mishra S. K.
Published: March 2021

A photoelectron sheath couples with positively charged floating fine dust to constitute a two-component dusty plasma over the sunlit locations on the Moon—the possibility of small amplitude nonlinear dust acoustic (DA) excitations in this plasma environment is investigated. The standard reductive perturbation approach has been adopted to analyze the nonlinear evolution of photoelectron-dust plasma dynamics, including the equations for dust fluid continuity and momentum, plasma potential (Poisson equation), and nonadiabatic dust charge variation. The photoemission from and photoelectron accretion on dust particles are considered dominant charging mechanisms where Fowler's formulation for the photoemission from the positively charged spherical dust and non-Maxwellian nature of the sheath photoelectrons are consistently accounted for. The dust charge variation induces collisionless dissipation, which damps amplitude and reduces the velocity of propagating DA waves. Under typical solar irradiation conditions, the nonlinear analysis of the sunlit lunar dusty plasma is supposed to support DA solitary and DA shock wave structures of both rarefied and compressive nature; the dominance of dispersion and dissipation effects in the fluid dynamics is shown to exhibit oscillatory and monotonic shock waves, respectively. The passage of such nonlinear DA structures might energize the ambient charged dust and photoelectrons locally and could be an important mechanism for energy/particle transport in the vicinity of the sunlit locations over the Moon.
Discovery of single nucleotide polymorphisms in bone morphogenetic protein (
Authors: Simon Shalu Elizabeth , Radhika G. , Aravindakshan T. V. , Thomas Marykutty , Raji K.
Published: March 2021

Context Two native goat breeds from Kerala, Malabari and Attappady Black, differ significantly in prolificacy (i.e. no. of kids born/kidding). Prolificacy is an important economic trait and the subject of genetic research showing that bone morphogenetic protein (BMP) genes have a significant effect. Double digest restriction-site associated DNA sequencing (ddRADseq) is a highly efficient and low cost technology for high density discovery of single nucleotide polymorphisms (SNPs), which could serve as predictive markers for animal breeding programs. Aims The study was aimed at discovering SNPs in BMP genes that affect prolificacy, using ddRADseq followed by validation of selected SNP. Methods Blood DNA samples of 10 highly prolific Malabari and 10 less prolific Attappady Black goats were pooled by group and subjected to ddRADseq. SNPs observed in BMP genes were investigated and compared between groups. A validation study was done for the c.614–32789C>T variant in 100 Malabari and 50 Attappady Black goats by using PCR-RFLP. Key results In total, 6333 variants were identified by ddRADseq. Three variants were identified in BMP genes, which included two intronic variants c.614–32789C>T and c.490+6793T>C, in genes BMP6 and BMP5 and a downstream gene variant near the BMPR1B gene. According to ddRADseq data, variants in BMP5 and BMP6 differed in allelic distribution between Malabari and Attappady Black goats. For c.490+6793T>C in BMP5, the CC genotype was predominant in the highly prolific Malabari whereas TC was present in the Attappady Black group. The variant c.614–32789C>T in BMP6 was genotyped as TC in Malabari and CC in Attappady Black goats by ddRADseq. This variant was predicted to have an effect on splicing, according to the tool SplicePort. On the basis of bioinformatics analysis and the role of BMP6 gene in follicular dynamics, the variant in BMP6 was selected for further validation studies. All three genotypes were identified by PCR-RFLP; the C allele was the rare allele in the population with an allele frequency of 0.36. Presence of both alleles C and T and the three genotypes CC, TC and TT in this larger population substantiated the robustness of ddRADseq technique. Conclusions The technique discovered high confidence SNPs, which could be used for further validation and association studies to develop markers for selection of animals and for genetic improvement of this complex trait. Implications Techniques such as ddRADseq provide a large number of SNPs, and investigation of those polymorphisms found across the genome will help to identify new loci affecting traits of interest. This, in turn, will aid in exploring genetically complex traits in a faster and cheaper manner.
Influence of calf vigour and suckling assistance from birth to weaning in Guzerá beef cattle
Authors: Vilela Pires Bianca , de Freitas Luara Afonso , Voltareli da Silva Gabriele , Brasil Garcia Pimenta Neves Pereira Lima Sérgio , dos Santos Gonçalves Cyrillo Joslaine Noely , Bonvino Stafuzza Nedenia , Pereira de Lima Maria Lúcia , Paro de Paz Claudia Cristina
Published: March 2021

Context Maternal ability, cow nutrition, and calf sex are factors that affect beef cattle production in extensive systems. The Guzerá cattle is an important breed in Brazil, where satisfactory growth rates are reported; however, studies on post-parturition calf and cow behaviour are scarce. Aims This study aimed to identify the influence of vigour at birth (ability to stand and suckle without assistance) and human assistance in colostrum intake (HA) on the haematological profile, cortisol concentration, and growth until weaning of Guzerá beef calf. Methods The following traits were observed in 73 male and 83 female calves: cow age at calving, sex, birthweight, vigour, HA, haematological profile, cortisol concentration, bodyweight at 120 days (W120), weaning weight, average daily gain and mortality. Variance analysis was performed using the general linear model procedure of the SAS software. Key results Haematocrit (P = 0.04) and red blood cells (P = 0.004) were higher in calves requiring HA. Cortisol was also higher (P = 0.03) in calves that required HA (81.34 ng/mL × 59.40 ng/mL). The weaning weight and average daily gain were higher (P < 0.05) in calves that did not require HA and showed good vigour (200.38 kg and 0.83 kg/day respectively) than in calves that required HA and showed good vigour (163.7 kg and 0.68 kg/day respectively). The mortality rate was higher in calves that showed poor vigour at birth (25%). Conclusions Both vigour and the need for HA are important traits that should be evaluated during the development of newborn calves. These assessments in the herd can contribute to minimise the mortality rate and maximise the health and weight gain until weaning of beef calves. Implications Few studies have reported the role of vigour and colostrum intake in the development of calves. Despite the difficulty of human interference in extensive cattle farming, the calf vigour combined with human assistance at birth can minimise the losses and increase the performance of beef cattle.
Knowledge, beliefs and attitudes of general practitioners and general practice nurses regarding influenza vaccination for young children
Authors: Ruiz Haley , Halcomb Elizabeth , Seale Holly , Horgan Alyssa , Rhee Joel
Published: March 2021

Annual vaccination is effective in reducing the harms associated with seasonal influenza. However, the uptake of influenza vaccine has historically been low in children. This paper reports a descriptive survey that sought to explore the beliefs, attitudes, and knowledge of general practitioners (GPs) and general practice nurses (GPNs) towards influenza vaccination in young children. Both GPs and GPNs working in the Illawarra Shoalhaven Local Health District (ISLHD) in NSW, Australia, were invited via email, fax and social media to participate in the study. A total of 121 participants completed the survey. Most participants had a high level of support and knowledge of influenza immunisation in young children. Barriers to influenza immunisation in young children included perceived hesitancy in parents and competing clinical demands. The participants strongly supported funding of the vaccine, with 90.9% feeling that parents would be less likely to vaccinate their children if the vaccine were no longer free. Both GPs and GPNs differed in the use of influenza vaccination resources. The participants had a positive attitude to influenza immunisation in young children and strongly supported continued funding of the vaccine. Dedicated young children’s influenza vaccination clinics run by general practices or in the community could reduce the impact of competing clinical demands.
A cartographic approach to sentence production in aphasia
Authors: Wang Haiyan , Liu Xinmiao , Li Xin
Published: March 2021

There is much evidence that individuals with aphasia (IWA) are impaired in tense or aspectual inflections and the production of non-canonical sentences like passives. On the Cartographic Approach (CA), passives are represented at the lower node in the syntactic tree, with tense or aspectual elements at the higher node. This hierarchical structure can be used to account for the selective impairments in aphasic production. The present study reports the empirical findings from Chinese agrammatism using the theory of cartography. It is found that the performance of IWA with different degrees of severity is associated with different nodes (CP, TP, and vP) in the syntactic tree. Notably, the Chinese-speaking IWA are severely impaired in vP-related elements. Finally, the present study highlights the significance of adopting a cartographic approach to aphasia studies.
Immunodominant antibody germlines in COVID-19
Authors: Andreano Emanuele , Rappuoli Rino
Published: March 2021

The neutralizing antibody response to SARS-CoV-2 is dominated by antibodies deriving from germlines IGHV3-53/IGHV3-66, which are also associated with self-reacting antibodies. Could vaccines avoid the expansion of this immunodominant response, decrease the risk of autoimmunity, and still protect against emerging SARS-CoV-2 variants?
A note on the vacuum structure of lattice Euclidean quantum gravity: ‘birth’ of macroscopic space-time and PT-symmetry breaking
Authors: Vergeles S N
Published: March 2021

It is shown that the ground state or vacuum of the lattice quantum gravity is significantly different from the ground states of the well-known vacua in QED, QCD, et cetera. In the case of the lattice quantum gravity, the long-wavelength scale vacuum structure is similar to that in QED, moreover the quantum fluctuations of gravitational degrees of freedom are very reduced in comparison with the situation in QED. But the small scale (of the order of the lattice scale) vacuum structure in gravity is significantly different from that in the long-wavelength scales: the fluctuation values of geometrical degrees of freedom (tetrads) are commensurable with theirs most probable values. It is also shown that the macroscopic Universe can exist only in the presence of fermion fields. In this case, spontaneous breaking of the PT symmetry occurs.
Laboratory calibration for multidirectional spectroradiometers
Authors: Niedzwiedz Angelika , Duffert Jens , Tobar-Foster Mario , Quadflieg Esther , Seckmeyer Gunther
Published: March 2021

A method for the calibration of multidirectional spectroradiometers (MUDISs) capable of the simultaneous measurement of spectral radiance at different wavelengths is presented. The calibration of the spectroradiometer is challenging and crucial for high quality measurements of the angular dependence of the radiance. The calibration device consists of an integrating sphere (also known as Ulbrichtkugel), with a diameter of 100 cm, equipped with three 100 W lamps positioned in the lower hemisphere, with the input optics of the MUDIS directed towards the upper hemisphere. The MUDIS detects radiation from 113 different directions simultaneously in a wavelength range from 300 nm to 550 nm. Due to multiple reflections within the sphere, the radiance from the upper hemisphere is nearly homogeneous with deviations of less than 3% on average. Disregarding the 3% variability and assuming a homogeneous radiance inside the upper hemisphere of the integrating sphere, the spectral responsivities of all the MUDIS channels were determined based on the measured zenith radiance, which was detected by a pre-calibrated Network for the Detection of Atmospheric Composition Change reference spectroradiometer containing a scanning double monochromator with a unidirectional input optics. The input optics of the MUDIS contains thin fibers that should not be moved to avoid changes in the instrument’s responsivity. The proposed method is therefore suited to determine the absolute responsivity of the MUDIS for all directions.
A portable triaxial cell for beamline imaging of rocks under triaxial state of stress
Authors: Syed Amer , Tanino Yukie , LaManna Jacob M , Jacobson David L , Hussey Daniel S , Baltic Eli , Burca Genoveva
Published: March 2021

With recent developments in direct imaging techniques using x-ray and neutron imaging, there is an increasing need for efficient test setups to study the mechanical and/or transport behavior of porous rocks. Bespoke designs from commercial suppliers are expensive and often difficult to modify. This paper presents a novel design of a portable triaxial cell for imaging deformation (and a suggested adaptation to introduce fluid transport) through rocks/sand/soil under the triaxial states of stress representative of those encountered in the case of groundwater aquifers or subsurface hydrocarbon reservoirs. The design philosophy and the parameters are detailed so that interested researchers can use this experimental setup as a template to design and modify triaxial cells to suit their own experimental requirements. The design has been used in two imaging beamlines: Imaging and Material Science & Engineering (IMAT), ISIS facility, Harwell, Oxfordshire, UK, and BT2 of the National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, MD, USA. The mass attenuation coefficients extracted from the 2D radiograms of the triaxial cell were compared with those reported in the literature. Further suggestions for the adaptation of the triaxial cells for studying the mechanics of deformation and fracture in rocks are included.
An automated optimization strategy to design collimator geometry for small field radiation therapy systems
Authors: Wang Jinghui , Wang Lei , Maxim Peter G , Loo Billy W
Published: March 2021

Purpose. To develop an automated optimization strategy to facilitate collimator design for small-field radiotherapy systems. Methods and Materials. We developed an objective function that links the dose profile characteristics (FWHM, penumbra, and central dose rate) and the treatment head geometric parameters (collimator thickness/radii, source-to-distal-collimator distance (SDC)) for small-field radiotherapy systems. We performed optimization using a downhill simplex algorithm. We applied this optimization strategy to a linac-based radiosurgery system to determine the optimal geometry of four pencil-beam collimators to produce 5, 10, 15, and 20 mm diameter photon beams (from a 6.7 MeV, 2.1 mm FWHM electron beam). Two different optimizations were performed to prioritize minimum penumbra or maximum central dose rate for each beam size. We compared the optimized geometric parameters and dose distributions to an existing clinical system (CyberKnife). Results. When minimum penumbra was prioritized, using the same collimator thickness and SDC (40 cm) as a CyberKnife system, the optimized collimator upstream and downstream radii agreed with the CyberKnife system within 3%–14%, the optimized output factors agreed within 0%–8%, and the optimized transverse and percentage depth dose profiles matched those of the CyberKnife with the penumbras agreeing within 2%. However, when maximum dose rate was prioritized, allowing both the collimator thickness and SDC to change, the central dose rate for larger collimator sizes (10, 15, 20 mm) could be increased by about 1.5–2 times at the cost of 1.5–2 times larger penumbras. No further improvement in central dose rate for the 5 mm beam size could be achieved. Conclusions. We developed an automated optimization strategy to design the collimator geometry for small-field radiation therapy systems. Using this strategy, the penumbra-prioritized dose distribution and geometric parameters agree well with the CyberKnife system as an example, suggesting that this system was designed to prioritize sharp penumbra. This represents proof-of-principle that an automated optimization strategy may apply to more complex collimator designs with multiple optimization parameters.
Non-linear thermal resistance model for the simulation of high power GaN-based devices
Authors: García-Sánchez S , Íñiguez-de-la-Torre I , Pérez S , Ranjan K , Agrawal M , Lingaparthi R , Nethaji D , Radhakrishnan K , Arulkumaran S , Ng G I , González T , Mateos J
Published: March 2021

We report on the modeling of self-heating in GaN-based devices. While a constant thermal resistance is able to account for the self-heating effects at low power, the decrease of the thermal conductance of semiconductors when the lattice temperature increases, makes necessary the use of temperature dependent thermal resistance models. Moreover, in order to correctly account for the steep increase of the thermal resistance of GaN devices at high temperature, where commonly used models fail, we propose a non-linear model which, included in an electro-thermal Monte Carlo simulator, is able to reproduce the strongly non-linear behavior of the thermal resistance observed in experiments at high DC power levels. The accuracy of the proposed non-linear thermal resistance model has been confirmed by means of the comparison with pulsed and DC measurements made in devices specifically fabricated on doped GaN, able to reach DC power levels above 150 W mm−1 at biases below 30 V.
Autologous Fat Transplantation for Aesthetic Breast Augmentation: A Systematic Review and Meta-Analysis
Authors: Wu Yingjie , Hu Feng , Li Xueping , Yin Guoqian
Published: March 2021

Background

Autologous fat transplantation has already become a part of clinical practice for aesthetic breast augmentation even though evidence regarding its efficacy is still lacking.

Objectives

The authors sought to determine the current worldwide status and efficacy, techniques, and oncologic safety on this subject.

Methods

PubMed, EMBASE, and Cochrane Library databases were searched to identify all relevant studies.

Results

Eighty-four articles published between 1987 and April 2020, consisting of 6468 patients, were included, and 64 studies consisting of 5162 unique patients were included in the meta-analysis. Most studies had a low level of evidence (levels 2b-5); In this meta-analysis, there were 17 prospective cohort studies, 4 retrospective cohort studies, 6 case-control studies, and 38 case series. The publications were from 21 countries. Indications for autologous fat transplantation were aesthetic augmentation (93.2%) and congenital malformation (6.8%). Among the 5162 patients, 2 cases (0.04%) of cancer were reported. The meta-analysis revealed very high overall patient and surgeon satisfaction rates of 93% and 87%, respectively. Overall, only 1.56 sessions were needed to achieve the desired result. Long-term survival was calculated to be approximately 60% to 70% at 1-year follow-up. Only 8% of procedures resulted in clinical complications, and 5% of patients required biopsy because of abnormal clinical or radiological findings.

Conclusions

Autologous fat transplantation seems to be a major tool in aesthetic breast augmentation. Preoperative patient selection is essential but under-reported. Future research should focus on evaluating the technical and patient factors influencing the rate of fat survival and its oncological safety.

Level of Evidence: 4
Subcutaneous Face and Neck lift: A Traditional Method With Definite Effects Among Asians
Authors: Wang Guanhuier , Zhao Runlei , Bi Ran , Xie Hongbin
Published: March 2021

Background

The mainstream facelifts in Western countries always involve the superficial fascia/superficial musculoaponeurotic system treatment. Meanwhile, subcutaneous face and neck lifts are widely applied among Asians.

Objectives

The authors sought to evaluate outcomes of subcutaneous face and neck lift, including patient-reported and 3-dimensional (3D) measurement outcomes, and report on details of surgical procedures.

Methods

Patients who received a subcutaneous face and neck lift from January 2017 to June 2019 were asked to complete FACE-Q scales, and facial information was collected by the Vectra 3D imaging system preoperatively and postoperatively. Volume changes in midface and possible displacement of facial landmarks were measured. The range of dissection and the amount of skin removed were recorded intraoperatively.

Results

In total, 119 patients (median age, 46 years, interquartile range, 40-53 years) received a subcutaneous face and neck lift. Among them, 88 patients completed pre- and postoperative FACE-Q scales. Patients’ satisfaction with facial subunits improved and wrinkles were significantly relieved (P < 0.001). Nineteen patients (38 midface sides) completed 3D image data collection. Postoperatively, zygomatic volume increased, and nasolabial and lateral cheek volumes decreased (volume change of 2.2 ± 1.3 mL). Mouth, nose, and eye displacements were negligible postoperatively. The widths of skin removed at the middle temporal, front of the sideburns, upper helix, earlobe, and retro-auricular were 13.8 ± 1.9 mm, 19.6 ± 3.1 mm, 27.6 ± 3.9 mm, 16.4 ± 3.9 mm, and 32.2 ± 4.0 mm, respectively.

Conclusions

The authors’ subcutaneous face and neck lift was effective in relieving nasolabial sagging, improving wrinkles, and achieving facial rejuvenation.

Level of Evidence: 4
Measuring Instruments for Empowerment in Social Work: A Scoping Review
Authors: Noordink Thomas , Verharen Lisbeth , Schalk René , van Eck Marcel , van Regenmortel Tine
Published: March 2021

Empowerment is seen as an important thinking and working framework for social work. Ideally, it is possible to measure the empowering effects of social work. However, various factors complicate measuring empowerment, making it a difficult exercise. In past decades many instruments for measuring empowerment have been developed and there are many variations in the way these instruments have been developed. The aim of this review is to provide a comprehensive overview of the available instruments, scales or questionnaires that intent to measure the empowerment of users of social work in different contexts of social work, by means of a scoping review. A total of 2,711 studies were screened, resulting in 49 unique instruments for measuring empowerment in contexts related to social work. The results show that the found instruments are almost exclusively Patient-Reported Outcome Scales. Whilst many instruments measure individual empowerment, only a few measure community empowerment. The results also show that there are many variations in which instruments operationalise empowerment. This overview provides social work organisations and its researchers an overview of measuring tools necessary to measure the effects of their efforts, allowing them to build on what is available.
Disruption of the blood–brain barrier in 22q11.2 deletion syndrome
Authors: Crockett Alexis M , Ryan Sean K , Vásquez Adriana Hernandez , Canning Caroline , Kanyuch Nickole , Kebir Hania , Ceja Guadalupe , Gesualdi James , Zackai Elaine , McDonald-McGinn Donna , Viaene Angela , Kapoor Richa , Benallegue Naïl , Gur Raquel , Anderson Stewart A , Alvarez Jorge I
Published: March 2021

Neuroimmune dysregulation is implicated in neuropsychiatric disorders including schizophrenia. As the blood−brain barrier is the immunological interface between the brain and the periphery, we investigated whether this vascular phenotype is intrinsically compromised in the most common genetic risk factor for schizophrenia, the 22q11.2 deletion syndrome (22qDS). Blood−brain barrier like endothelium differentiated from human 22qDS+schizophrenia-induced pluripotent stem cells exhibited impaired barrier integrity, a phenotype substantiated in a mouse model of 22qDS. The proinflammatory intercellular adhesion molecule-1 was upregulated in 22qDS+schizophrenia-induced blood–brain barrier and in 22qDS mice, indicating compromise of the blood–brain barrier immune privilege. This immune imbalance resulted in increased migration/activation of leucocytes crossing the 22qDS+schizophrenia blood−brain barrier. We also found heightened astrocyte activation in murine 22qDS, suggesting that the blood−brain barrier promotes astrocyte-mediated neuroinflammation. Finally, we substantiated these findings in post-mortem 22qDS brain tissue. Overall, the barrier-promoting and immune privilege properties of the 22qDS blood–brain barrier are compromised, and this might increase the risk for neuropsychiatric disease.
Sex differences in acute cardiovascular care: a review and needs assessment
Authors: Vallabhajosyula Saraschandra , Verghese Dhiran , Desai Viral K , Sundaragiri Pranathi R , Miller Virginia M
Published: March 2021

Despite significant progress in the care of patients suffering from cardiovascular disease, there remains a persistent sex disparity in the diagnosis, management, and outcomes of these patients. These sex disparities are seen across the spectrum of cardiovascular care, but, are especially pronounced in acute cardiovascular care. The spectrum of acute cardiovascular care encompasses critically ill or tenuous patients with cardiovascular conditions that require urgent or emergent decision-making and interventions. In this narrative review, the disparities in the clinical course, management, and outcomes of six commonly encountered acute cardiovascular conditions, some with a known sex-predilection will be discussed within the basis of underlying sex differences in physiology, anatomy, and pharmacology with the goal of identifying areas where improvement in clinical approaches are needed.
New biomarkers from multiomics approaches: improving risk prediction of atrial fibrillation
Authors: Kornej Jelena , Hanger Vanessa A , Trinquart Ludovic , Ko Darae , Preis Sarah R , Benjamin Emelia J , Lin Honghuang
Published: March 2021

Atrial fibrillation (AF) is a common cardiac arrhythmia leading to many adverse outcomes and increased mortality. Yet the molecular mechanisms underlying AF remain largely unknown. Recent advances in high-throughput technologies make large-scale molecular profiling possible. In the past decade, multiomics studies of AF have identified a number of potential biomarkers of AF. In this review, we focus on the studies of multiomics profiles with AF risk. We summarize recent advances in the discovery of novel biomarkers for AF through multiomics studies. We also discuss limitations and future directions in risk assessment and discovery of therapeutic targets for AF.
The RACE to the EAST. In pursuit of rhythm control therapy for atrial fibrillation—a dedication to Harry Crijns
Authors: Reissmann Bruno , Breithardt Günter , Camm A John , Van Gelder Isabelle C , Metzner Andreas , Kirchhof Paulus
Published: March 2021

The RACE trial was one of the first landmark trials to establish whether restoring and maintaining sinus rhythm could reduce morbidity and mortality in patients with atrial fibrillation (AF). Its neutral outcome shaped clinical decision-making for almost 20 years. However, there were two important treatment-related factors associated with mortality of rhythm control therapy at that time: One was safety of antiarrhythmic drug therapy, and the other one withdrawal of anticoagulation after restoration of sinus rhythm. Both concerns have been overcome, and, moreover, important knowledge considering the importance of time for the treatment of AF has been gained. These insights led to the concept of the EAST-AFNET 4 trial, and after more than two decades in the pursuit of ongoing therapeutic improvement, early rhythm control therapy has demonstrated to reduce a composite of cardiovascular death, stroke, and hospitalization for worsening of HF or acute coronary syndrome, by 21% (first primary outcome, absolute reduction 1.1 per 100 patient-years). For this entire period, Harry Crijns characterized the treatment of AF patients, and contributed decisively to realizing the benefit of rhythm control therapy. It is almost easier to list the clinical trials without Harry's involvement than to list those which he co-designed and led.
Non-human primate and human malaria: past, present and future
Authors: Antinori Spinello , Bonazzetti Cecilia , Giacomelli Andrea , Corbellino Mario , Galli Massimo , Parravicini Carlo , Ridolfo Anna Lisa
Published: March 2021

Background

Studies of the malaria parasites infecting various non-human primates (NHPs) have increased our understanding of the origin, biology and pathogenesis of human Plasmodium parasites.

This review considers the major discoveries concerning NHP malaria parasites, highlights their relationships with human malaria and considers the impact that this may have on attempts to eradicate the disease.

Results

The first description of NHP malaria parasites dates back to the early 20th century. Subsequently, experimental and fortuitous findings indicating that some NHP malaria parasites can be transmitted to humans have raised concerns about the possible impact of a zoonotic malaria reservoir on efforts to control human malaria.

Advances in molecular techniques over the last 15 years have contributed greatly to our knowledge of the existence and geographical distribution of numerous Plasmodium species infecting NHPs, and extended our understanding of their close phylogenetic relationships with human malaria parasites. The clinical application of such techniques has also made it possible to document ongoing spillovers of NHP malaria parasites (Plasmodium knowlesi, P. cynomolgi, P. simium, P. brasilianum) in humans living in or near the forests of Asia and South America, thus confirming that zoonotic malaria can undermine efforts to eradicate human malaria.

Conclusions

Increasing molecular research supports the prophetic intuition of the pioneers of modern malariology who saw zoonotic malaria as a potential obstacle to the full success of malaria eradication programmes. It is, therefore, important to continue surveillance and research based on one-health approaches in order to improve our understanding of the complex interactions between NHPs, mosquito vectors and humans during a period of ongoing changes in the climate and the use of land, monitor the evolution of zoonotic malaria, identify the populations most at risk and implement appropriate preventive strategies.