bluuebunny/crossref_metadata_2025 huggingface dataset:
Titanium: A Unique Metal for Radical Dehydroxylative Functionalization of Alcohols
Authors: Shu Xing-Zhong , Pang Xiaobo
Published: March 2021

The dehydroxylative functionalization of alcohols is synthetic appealing, but it remains a long-term challenge in the synthetic community. Low-valent titanium has shown the power to produce carbon radicals from alcohols via homolytic cleavage of the C–OH bonds and thus offers the potential to overcome this problem. In this perspective manuscript, we summarized the recent advance on radical dehydroxylative transformation of alcohols either promoted or catalyzed by titanium. The limitation and outlook of the studies in this field are also provided.

1 Introduction

2 Recent Developments in Dehydroxylative Functionalization of Alcohols

2.1 Stoichiometric Titanium Complexes Mediated Homolysis of Alcohols

2.2 Radical Dehydroxylative Functionalization of Alcohols by Ti Catalysis

3 Summary and Outlook
Impact of Homeopathic Treatment on the Quality of Life of Women with Chronic Diseases: A Randomized Controlled Pragmatic Trial
Authors: Champs Natália S. , Lopes Julia G. , Sousa Paula C. , Souza Clariana C. , Justo Barbara L.T. , Dutra Dayane M. , Mendes Adrienne M.S. , Santos Claudia Prass , Tavares Rubens L.C.
Published: March 2021

Background Despite the increasing demand for complementary and integrative medicine, only a few studies have evaluated the effect of these types of treatments on the quality of life (QoL) of patients with chronic diseases. The objective of this study was to evaluate the QoL of women treated with homeopathy within the Public Health System of Belo Horizonte, Brazil.

Methods This is a prospective randomized controlled pragmatic trial. The patients were divided into two independent groups, one group underwent homeopathic treatment in the first 6-month period and the other did not receive any homeopathic treatment. In both randomized groups, patients maintained their conventional medical treatment when necessary. The World Health Organization Quality of Life abbreviated questionnaire (WHOQOL-BREF) was used for QoL analysis prior to treatment and 6 months later.

Results Randomization afforded similar baseline results in three domains of QoL analysis for both groups. After 6 months' treatment, there was a statistically significant difference between groups in the physical domain of WHOQOL-BREF: the average score improved to 63.6 ± (SD) 15.8 in the homeopathy group, compared with 53.1 ± (SD) 16.7 in the control group.

Conclusions Homeopathic treatment showed a positive impact at 6 months on the QoL of women with chronic diseases. Further studies should be performed to determine the long-term effects of homeopathic treatment on QoL and its determinant factors.
Comparative Study on Method of Threshold Estimation: Distortion Product Threshold Test versus Pure Tone Threshold Test
Authors: Mehta Gunjan , Neupane Anuj Kumar , Mistri Abhishek , Joshi Hiral , Shah Nirmit
Published: March 2021

Introduction Distortion product otoacoustic emissions (DPOAEs) can be helpful in estimating the hearing thresholds by extrapolating the DPOAE input/output function with the help of scissor paradigm, and thus the following study aims at assessing its reliability by comparing DPOAE thresholds with those obtained by behavioral responses at pure tones on various frequencies.

Materials and Methods Fifty participants having normal hearing sensitivity were included in the study. Pure tone (PT) audiometry was carried out on all participants to determine PT thresholds in both ears. DPOAE threshold test was administered and thresholds at 1, 2, 4, and 8 kHz were compared accordingly.

Results The result indicated significant difference between the two methods of threshold estimation where the mean difference was found to be 3 decibel (dB) and 4 dB for left and right ears, respectively. Shapiro-Wilk test revealed normal distribution (p > 0.05) of the data. Hence, parametric paired t-test was performed, which revealed significant difference between PT and distortion product thresholds.

Conclusion Study concludes as having good clinical applicability in assessing neonates and infants.
Rehabilitation of Concussion and Persistent Postconcussive Symptoms
Authors: Wilber Charles G. , Leddy John J. , Bezherano Itai , Bromley Lacey , Edwards Amanda E. , Willer Barry S. , Haider Mohammad N.
Published: March 2021

Concussion and persistent postconcussive symptoms (PPCS) are encountered by clinicians in sports medicine, pediatrics, neurology, physiatry, emergency medicine, and primary care. Clinical management may require a multidisciplinary approach. This article presents a structured method for the diagnosis of concussion and PPCS in the outpatient setting, which includes a history, physical examination, and additional tests as clinically indicated to help identify underlying symptom generators. Treatment for concussion and PPCS should be individualized, based on predominant signs and symptoms, and can include subsymptom threshold aerobic exercise, cervical physical therapy, vestibulo-ocular rehabilitation, behavioral and cognitive psychotherapy, and some symptom-specific pharmacological therapies.
Motor Recovery: How Rehabilitation Techniques and Technologies Can Enhance Recovery and Neuroplasticity
Authors: Braun Robynne G. , Wittenberg George F.
Published: March 2021

There are now a large number of technological and methodological approaches to the rehabilitation of motor function after stroke. It is important to employ these approaches in a manner that is tailored to specific patient impairments and desired functional outcomes, while avoiding the hype of overly broad or unsubstantiated claims for efficacy. Here we review the evidence for poststroke plasticity, including therapy-related plasticity and functional imaging data. Early demonstrations of remapping in somatomotor and somatosensory representations have been succeeded by findings of white matter plasticity and a focus on activity-dependent changes in neuronal properties and connections. The methods employed in neurorehabilitation have their roots in early understanding of neuronal circuitry and plasticity, and therapies involving large numbers of repetitions, such as robotic therapy and constraint-induced movement therapy (CIMT), change measurable nervous systems properties. Other methods that involve stimulation of brain and peripheral excitable structures have the potential to harness neuroplastic mechanisms, but remain experimental. Gaps in our understanding of the neural substrates targeted by neurorehabilitation technology and techniques remain, preventing their prescriptive application in individual patients as well as their general refinement. However, with ongoing research—facilitated in part by technologies that can capture quantitative information about motor performance—this gap is narrowing. These research approaches can improve efforts to attain the shared goal of better functional recovery after stroke.
Hereditary Myelopathies
Authors: Walker Melissa A.
Published: March 2021

Hereditary myelopathies are an important and likely underappreciated component of neurogenetic disease. While previously distinctions have been made by age of onset, the growing power and availability of high-quality neuroimaging and next-generation sequencing are increasingly expanding classical phenotypes and diminishing the utility of age-based classifications. Increasingly, cases of “atypical” disease presentations are challenging past assumptions regarding the age of onset and survival in many disorders and identifying allelic syndromes in others. Despite this, there is poor awareness of the potential for spinal involvement in many diseases that typically affect the brain. Broadly speaking, congenital myelopathies can be neuroanatomically grouped into motor neuron, axonopathy, spinocerebellar, cerebroleukodystrophy, and pan-neuraxis (generally central nervous system predominant with associated axonopathy) disorders.

Here, we review hereditary causes of myelopathy, organized by neuroanatomy, and highlight atypical presentations. We discuss findings concerning an underlying genetic etiology for myelopathy, as well as practical, technical, and ethical considerations of diagnostic genetic testing.
Broadband femtosecond spectroscopic ellipsometry
Authors: Richter Steffen , Rebarz Mateusz , Herrfurth Oliver , Espinoza Shirly , Schmidt-Grund Rüdiger , Andreasson Jakob
Published: March 2021

We present a setup for time-resolved spectroscopic ellipsometry in a pump–probe scheme using femtosecond laser pulses. As a probe, the system deploys supercontinuum white light pulses that are delayed with respect to single-wavelength pump pulses. A polarizer–sample–compensator–analyzer configuration allows ellipsometric measurements by scanning the compensator azimuthal angle. The transient ellipsometric parameters are obtained from a series of reflectance-difference spectra that are measured for various pump–probe delays and polarization (compensator) settings. The setup is capable of performing time-resolved spectroscopic ellipsometry from the near-infrared through the visible to the near-ultraviolet spectral range at 1.3 eV–3.6 eV. The temporal resolution is on the order of 100 fs within a delay range of more than 5 ns. We analyze and discuss critical aspects such as fluctuations of the probe pulses and imperfections of the polarization optics and present strategies deployed for circumventing related issues.
On indefinite Kirchhoff-type equations under the combined effect of linear and superlinear terms
Authors: Sun Juntao , Wang Kuan-Hsiang , Wu Tsung-fang
Published: March 2021

We investigate the eigenvalue problem for Kirchhoff type equations involving a superlinear perturbation, namely, −a∫RN|∇u|2dx+1Δu+μV(x)u=λf(x)u+g(x)|u|p−2u in RN, where V∈C(RN) is a potential well with the bottom Ω≔int{x∈RN|V(x)=0}. When N = 3 and 4 < p < 6, for each a > 0 and μ sufficiently large, we obtain at least one positive solution for 0 < λ ≤ λ1(fΩ), while at least two positive solutions exist for λ1(fΩ) < λ < λ1(fΩ) + δa without any assumption on the integral ∫Ωg(x)ϕ1pdx, where λ1(fΩ) > 0 is the principal eigenvalue of −Δ in H01(Ω) with the weight function fΩ ≔ f|Ω and ϕ1 > 0 is the corresponding principal eigenfunction. When N ≥ 3 and 2 < p < min{4, 2*}, for μ sufficiently large, we conclude that (i) at least two positive solutions exist for 0 < a < a0(p) and 0 < λ < λ1(fΩ); (ii) if ∫Ωg(x)ϕ1pdx<0, at least three positive solutions exist for 0 < a < a0(p) and λ1(fΩ)≤λ<λ1(fΩ)+δ̄a; and (iii) if ∫Ωg(x)ϕ1pdx>0, at least two positive solutions exist for a ≥ a0(p) and 0≤λa+<λ<λ1(fΩ).
Identifying influential nodes: A new method based on network efficiency of edge weight updating
Authors: Shang Qiuyan , Zhang Bolong , Li Hanwen , Deng Yong
Published: March 2021

Identification of influential nodes in complex networks is an area of exciting growth since it can help us to deal with various problems. Furthermore, identifying important nodes can be used across various disciplines, such as disease, sociology, biology, engineering, just to name a few. Hence, how to identify influential nodes more accurately deserves further research. Traditional identification methods usually only focus on the local or global information of the network. However, only focusing on a part of the information in the network will lead to the loss of information, resulting in inaccurate results. In order to address this problem, an identification method based on network efficiency of edge weight updating is proposed, which can effectively incorporate both global and local information of the network. Our proposed method avoids the lack of information in the network and ensures the accuracy of the results as much as possible. Moreover, by introducing the iterative idea of weight updating, some dynamic information is also introduced into our proposed method, which is more convincing. Varieties of experiments have been carried out on 11 real-world data sets to demonstrate the effectiveness and superiority of our proposed method.
Shear augmented microvascular solute transport with a two-phase model: Application in nanoparticle assisted drug delivery
Authors: Roy Ashis Kumar , Shaw Sachin
Published: March 2021

Solutal dispersion phenomena are associated with the nanoparticle-based drug delivery in the cardiovascular system to cure cardiovascular disorder. In the present problem, we explored the solutal transport for an unsteady blood flow through a microvessel with wall absorption. The rheology of blood is characterized by a two-fluid model similar to three-layer flow, namely, the core region, the intermediate region, and the peripheral region. The nature of the blood is considered as Casson fluid near the axis of the microvessel and Newtonian fluid close to the wall of the microvessel (at the intermediate and peripheral region). The peripheral region and the wall of the microvessel are permeable, and the permeability of the microvessel wall is defined by the Darcy–Brinkman model. The permeability of the inner surface of the microvessel is subjected to a slip condition at the surface. The stress-jump condition acts at the interface of the intermediate and peripheral region. The impact of the absorption parameter, velocity slip, yield stress, stress jump constant, nanoparticle volume fraction, and permeability on the velocity, exchange coefficient, convection coefficient, dispersion coefficient, and mean concentration is shown. It observed that the mean concentration boosts by the yield stress, nanoparticle volume fraction, and absorption parameters. The stress jump constant and permeability boost the convection coefficient, while the dispersion coefficient is restricted by the yield stress and absorption parameter.
Modal polarization analysis using Fourier-rectangular function transform in a cylindrical plasma
Authors: Nishimura D. , Fujisawa A. , Nagashima Y. , Moon C. , Yamasaki K. , Kobayashi T.-K. , Inagaki S. , Yamada T. , Kawachi Y. , Kasuya N. , Kosuga Y. , Sasaki M.
Published: March 2021

Fourier-rectangular function (FRF) transform [K. Yamasaki et al., J. Appl. Phys. 126, 043304 (2019)] is used to analyze the structure and dynamics of plasma with cylindrical symmetry. In this article, a new technique based on FRF transform is proposed to elucidate the polarization characteristics of azimuthal modes and fluctuations. The application results are shown for a two-dimensional tomography image of linear cylindrical plasma. The method successfully resolves the polarization characteristics of azimuthal modes and attributes the intermittent behavior of the m=1 mode to its polarization characteristics.
Evolution of turbulent pipe flow recovery over a square bar roughness element at a range of Reynolds numbers
Authors: Goswami Shubham , Hemmati Arman
Published: March 2021

The Reynolds number effects and scaling on response and recovery of flow over square bar roughness elements are numerically examined at a range of Reynolds numbers between 5 × 103 and 1.56 × 105. The square bar roughness element has a height of 0.05D, where D is the pipe diameter. The response is examined using streamline plots and reattachment lengths. An asymptotic trend is observed in reattachment lengths with increasing the Reynolds number. The recovery is examined quantitatively by tracing the transport of Reynolds shear stress downstream of the roughness element. While the overall trend for recovery is similar for all Reynolds numbers, the collapse of stresses toward the wall appears earlier at lower Reynolds numbers. The recovery trends follow a power-law of diffusion toward the centerline. The point of initial response, that is, the point of collapse, appears independent from the effects of Reynolds numbers at Re ≥ 5.0 × 104.
Thermal conductivity of the n = 1–5 and 10 members of the (SrTiO3)nSrO Ruddlesden–Popper superlattices
Authors: Dawley Natalie M. , Pek Ella K. , Lee Che-Hui , Ragasa Eugene J. , Xiong Xue , Lee Kiyoung , Phillpot Simon R. , Chernatynskiy Aleksandr V. , Cahill David G. , Schlom Darrell G.
Published: March 2021

Unlike many superlattice structures, Ruddlesden–Popper phases have atomically abrupt interfaces useful for interrogating how periodic atomic layers affect thermal properties. Here, we measure the thermal conductivity in thin films of the n = 1–5 and 10 members of the (SrTiO3)nSrO Ruddlesden–Popper superlattices grown by molecular-beam epitaxy and compare the results to a single crystal of the n = 1 Ruddlesden–Popper SrLaAlO4. The thermal conductivity cross-plane to the superlattice layering (k33) is measured using time-domain thermoreflectance as a function of temperature and the results are compared to first-principles calculations. The thermal conductivity of this homologous series decreases with increasing interface density. Characterization by x-ray diffraction and scanning transmission electron microscopy confirms that these samples have a Ruddlesden–Popper superlattice structure.
Homogeneous relaxation and shock wave problems: Assessment of the simplified and generalized Bernoulli trial collision schemes
Authors: Shoja-Sani Ahmad , Roohi Ehsan , Stefanov Stefan
Published: March 2021

The impetus of this paper is to assess the newly suggested direct simulation Monte Carlo (DSMC) collision schemes, that is, the “Simplified Bernoulli Trails (SBT)” and “Generalized Bernoulli Trials (GBT)” schemes in the prediction of the higher-order moments of the velocity distribution function for both confined and non-confined gas flows. Two fundamental rarefied gas dynamics problems are considered: spatially homogeneous relaxation process of a gas flow from a non-Maxwellian condition given by Bobylev–Krook–Wu exact (analytical) solution of the Boltzmann equation and the stationary shock wave problem. To perform the relaxation test, SBT and GBT schemes were implemented in the DSMC0F program. For the shock wave test, changes were made in the DSMC1 code to include the SBT and GBT schemes. A detailed comparison of the SBT and GBT collision schemes in treating the higher-order moments of the velocity distribution function and comparison with theory and the solution of the standard No-Time-Counter (NTC) method and its new variant, nearest neighbor scheme, using the DS1 code, is reported. Some higher moments beyond the usual moments were computed. The results of the fourth moment of the velocity distribution function in the homogeneous relaxation problem show that while both collision schemes produce identical results at an ample time, the initial relaxation process indicates the difference between the schemes. Even though the NTC schemes required a large number of particles per cell to produce the same results as the theory, the SBT scheme successfully simulates the solution using a low number of particles per cell.
Dissipation and dilatation rates in premixed turbulent flames
Authors: Sabelnikov V. A. , Lipatnikov A. N. , Nishiki S. , Dave H. L. , Hernández Pérez F. E. , Song W. , Im Hong G.
Published: March 2021

Velocity dilatation and total, solenoidal, and dilatational dissipation rates of the total flow kinetic energy are extracted from three different direct numerical simulation databases obtained by three independent research groups using different numerical codes and methods (e.g., single-step chemistry and complex chemistry flames) from six different premixed turbulent flames associated with flamelet, thin reaction zone, and broken reaction zone regimes of turbulent burning. The results show that dilatational dissipation can be larger than solenoidal dissipation in the flamelet regime and is substantial in the thin reaction zone regime. Accordingly, the influence of combustion-induced thermal expansion on the dissipation rate is not reduced to an increase in the mixture viscosity by the temperature. A simple criterion for identifying conditions associated with significant dilatational dissipation is discussed, and dilatational dissipation due to the influence of turbulence on mixing in preheat zones is argued to play a role even at high Karlovitz numbers Ka. In particular, the magnitude of dilatation fluctuations and probability of finding negative local dilatation are increased by Ka, thus implying that the impact of molecular transport of species and heat on the dilatation increases with increasing Karlovitz number.
Physics applied to electrochemistry: Tunneling reactions
Authors: Bevan Kirk H. , Foong Yee Wei , Shirani Javad , Yuan Shuaishuai , Abi Farraj Sinan
Published: March 2021

In this work, we explore how electrochemical tunneling reactions can be understood within the single-particle picture. That is, the formal approach in which band diagrams are typically utilized to understand electronic processes in solid-state materials and devices. This single-particle perspective is based upon the Gerischer–Hopfield description of electron transfer at solid–liquid interfaces. Both single and multiple electron tunneling reactions are discussed, as are related voltammetric concepts and trends. The impact of nuclear quantization on the Gerischer–Hopfield description is also addressed, as well as its compact representation of two probe electrochemical phenomena at low temperatures (often referred to as Franck–Condon blockade). In this manner, a perspective linking solid-state phenomena and tunneling electrochemical reactions is presented.
Turbulence topology evolution in weakly turbulent premixed flames
Authors: Mura Arnaud , Zhao Song
Published: March 2021

In turbulent premixed flames, not only the isotropy of velocity fluctuations is altered by the thermal expansion effect but also the dissipative structure of the turbulent flow field and the flow topology are also deeply influenced by the flame. Considering the joint probability density function of the second and third invariants of the velocity gradient tensor (VGT)—or its traceless counterpart—is a classical way to deduce the topology of turbulent flows at these smallest scales. These quantities are analyzed by considering direct numerical simulation databases of premixed flame kernel growth in homogeneous isotropic turbulence. Two conditions of turbulence–combustion interaction are considered, which correspond to two distinct values of the Bray number. The analysis of the VGT shows that the propagating premixed flame and its associated density variations significantly modify the turbulence structure and flow topology. To understand this behavior as the flow interacts with the flame front, Lagrangian dynamics of the VGT and its invariants are studied by considering the conditional mean rate of change vectors. Special emphasis is thus placed on the Lagrangian evolution equations of these invariants. To the best of authors' knowledge, this is first time that such budgets are scrutinized under premixed combustion conditions. The pressure Hessian contribution to the VGT invariant transport equations is shown to be one of the leading-order terms in this evolution, making it critically important to the flow dynamics and turbulence structure.
The influence of the equation of state on the cellular structure of gaseous detonations
Authors: Taileb S. , Melguizo-Gavilanes J. , Chinnayya A.
Published: March 2021

The propagation of multidimensional gaseous detonations at elevated pressures was investigated numerically. Initial conditions at which deviations from ideal gas are expected (i.e., p0 > 2 MPa) were used to assess whether real gas effects influence their multi-cellular structure. The simplest equation of state that accounts for real gas effects was selected, Noble–Abel, and compared with the results obtained using perfect gas. Approximate and exact relationships are provided for the von-Neumann and Chapman–Jouguet states, as well as sound speeds, for both equations of state. Results show that real gas effects alter the multi-cellular structure of gaseous detonations at elevated pressures. Moreover, neglecting these effects renders a more irregular structure than that obtained when real gas effects are reinstated. The source of the perceived instabilities was identified as a Mach bifurcation due to jetting and their growth was related to a shear layer triple point interaction, giving birth to new triple points. The more unstable structure seems to arise from an effective change in the isentropic coefficient that is not included in the perfect gas formulation.
Microstructure of epitaxial Mg3N2 thin films grown by MBE
Authors: John P. , Vennéguès P. , Rotella H. , Deparis C. , Lichtensteiger C. , Zúñiga-Pérez J.
Published: March 2021

The epitaxial growth of Mg3N2 thin films by molecular beam epitaxy has been recently achieved. This work presents the structural properties of the films, including grain sizes and lattice rotations, as assessed by x-ray diffraction and transmission electron microscopy. The films’ microstructure consists of well-aligned columnar grains 10 nm in diameter that nucleate at the film/substrate interface and display a significant column twist, in the order of 2.5°. As growth proceeds, tilted and twisted mosaic blocks overgrow these columns, as observed in many other epitaxial semiconductors. Yet, the rocking curves on symmetric reflections display extremely narrow peaks (∼50 arc sec), revealing a long-range spatial correlation between structural defects that should not be mistakenly considered a proof of high crystalline quality.
Wave redirection, localization, and non-reciprocity in a dissipative nonlinear lattice by macroscopic Landau–Zener tunneling: Theoretical results
Authors: Wang C. , Kanj A. , Mojahed A. , Tawfick S. , Vakakis A.
Published: March 2021

We consider an asymmetric dissipative network of two semi-infinite nonlinear lattices with weak linear inter-lattice coupling and study its capacity for passive wave redirection and non-reciprocity. Each lattice is composed of linearly grounded oscillators with essentially nonlinear (i.e., non-linearizable) next-neighbor intra-lattice coupling, and it supports breather propagation. Irreversible breather redirection between lattices is governed by a macroscopic analog of the quantum Landau–Zener tunneling (LZT) effect, whereby impulsive energy initially induced to the “excited lattice” is passively and irreversibly redirected to the “absorbing lattice.” Moreover, this wave redirection is realized only in a specific range of impulse intensity (energy), otherwise motion localization occurs. In this work, we show that LZT breather redirection in the dissipative network occurs only when the normalized linear inter-coupling stiffness is larger than the viscous damping ratio of the individual lattice oscillators, with breather arrest and localization occurring otherwise. Then, through a reduced-order model, we provide guidance for selecting the system parameters of the lattice network for robust breather redirection despite the presence of dissipation. To this end, we study the acoustic non-reciprocity and formulate a quantitative measure for studying it based on measured time-series responses at the four free boundaries of the finite network. Then, we show the dependence of non-reciprocity in this system on the intensity (energy) of the applied impulse. These results pave the way for conceiving practical nonlinear lattice networks with inherent capacities for passive wave redirection and acoustic non-reciprocity that are tunable (self-adaptive) to the applied impulsive excitations.
Variational method for elliptic systems with discontinuous nonlinearities
Authors: Pavlenko V. N. , Potapov D. K.
Published: March 2021

A system of two elliptic equations with discontinuous nonlinearities and homogeneous Dirichlet boundary conditions is studied. Existence theorems for strong and semiregular solutions are deduced using a variational method. A strong solution is called semiregular if the set on which the values of the solution are points of discontinuity of the nonlinearity with respect to the phase variable has measure zero. Classes of nonlinearities are distinguished for which the assumptions of the theorems established here hold. The variational approach in this paper is based on the concept of a quasipotential operator, by contrast with the traditional approach, which uses the generalized Clark gradient.

Bibliography: 22 titles.
Anomalous nanoparticle surface diffusion in LCTEM is revealed by deep learning-assisted analysis
Authors: Jamali Vida , Hargus Cory , Ben-Moshe Assaf , Aghazadeh Amirali , Ha Hyun Dong , Mandadapu Kranthi K. , Alivisatos A. Paul
Published: March 2021

Significance

Liquid cell transmission electron microscopy (LCTEM) is an emerging technique, which enables nanoscale visualization and tracking of single nanoparticles near interfaces with unprecedented spatial resolution. Here, we studied the diffusion of nanoparticles in LCTEM experiments using techniques powered by deep neural networks and statistical tests. We observed two underlying regimes of diffusive behavior which are governed by the interaction of the electron beam, the nanoparticle, the nearby substrate, and the liquid environment. This understanding forms the foundation to use LCTEM for single-nanoparticle tracking for a broad range of nanoparticles, interfaces, and liquids.
Drosophila
clock cells use multiple mechanisms to transmit time-of-day signals in the brain
Authors: Barber Annika F. , Fong Shi Yi , Kolesnik Anna , Fetchko Michael , Sehgal Amita
Published: March 2021

Significance

Despite our growing understanding of how the fly clock network maintains free-running rhythms of behavior and physiology, little is known about how information is communicated from the clock network to the rest of the brain to regulate behavior. We identify glutamate and acetylcholine as key neurotransmitters signaling from clock neurons to the pars intercerebralis (PI), a clock output region regulating circadian rhythms of sleep and metabolism. We report a link between
Drosophila
evening clock neurons and the PI, and find that the effect of clock neurons on output neuron physiology varies, suggesting that the same clock cells use multiple mechanisms simultaneously to drive cycling in output neurons.
Γ valley transition metal dichalcogenide moiré bands
Authors: Angeli Mattia , MacDonald Allan H.
Published: March 2021

Significance

At small twist angles, moiré patterns form in transition metal dichalcogenide bilayers. Using sophisticated ab initio calculations, we develop a model able to describe the band structure of these systems. We found that the moiré pattern acts as a long-wavelength modulating potential, with a sixfold rotational symmetry not present in the underlying lattice. The modulation potential reduces hole band widths and localizes electrons or holes around honeycomb or kagome lattice sites.
The taming of a scramblase
Authors: Whitlock Jarred M.
Published: March 2021

Intracellular pH joins the regulatory apparatus of the TMEM16 scramblase module.
Theoretical and numerical studies of breakdown phenomena triggered by microparticle in nitrogen gaps
Authors: Sun Qiang , Zhou Qian-hong , Yang Wei , Dong Ye , Zhang Han-tian , Song Meng-meng , Wu Yi
Published: March 2021

This paper studies microparticle-triggered breakdown phenomena in mm-scale nitrogen gaps based on theoretical analysis and numerical simulation. Secondary electron and field emission contributions are both considered when predicting the microparticle-initiated breakdown voltage. In the present model, the ionization coefficient of the microscale discharge is modified to recognize the significant reduction in the number of collisions that occurs when a microparticle is present. The theoretical analysis indicates that small particles have little influence on the gas-gap breakdown voltage unless field-emission effects are dominant. However, when large microparticles (radius 50 μm) are present, a significant decrease (more than 20%) in the minimum breakdown voltage can be observed regardless of the particle position in the gas gap. Therefore, one should endeavor to exclude large microparticles from the discharge process. A fluid model is then used to simulate the microparticle-initiated breakdown process in a gas switch. The microparticle radius is 10 μm and the distance between the microparticle and cathode is 1 μm. It can be found that the electrode–particle microdischarge generates regions of high-density plasma that finally trigger main-gap breakdown when a voltage of 2.5 kV–3.5 kV is applied. The calculated results are consistent with our theoretical analysis. This paper provides a quantitative research method to evaluate the influence of microparticles on gas breakdown and contributes to improving gas-switch insulation performance.
An optomechanical platform for quantum hypothesis testing for collapse models
Authors: Marchese Marta Maria , Belenchia Alessio , Pirandola Stefano , Paternostro Mauro
Published: March 2021

Quantum hypothesis testing has shown the advantages that quantum resources can offer in the discrimination of competing hypothesis. Here, we apply this framework to optomechanical systems and fundamental physics questions. In particular, we focus on an optomechanical system composed of two cavities employed to perform quantum channel discrimination. We show that input squeezed optical noise, and feasible measurement schemes on the output cavity modes, allow to obtain an advantage with respect to any comparable classical schemes. We apply these results to the discrimination of models of spontaneous collapse of the wavefunction, highlighting the possibilities offered by this scheme for fundamental physics searches.
Limited Evidence of Associations Between Executive Functioning and Alcohol Involvement In UK Adolescents
Authors: Burton Sam , Puddephatt Jo-Anne , Baines Laura , Sheen Florence , Warren Jasmine G , Jones Andrew
Published: March 2021

Aims

Deficits in motor inhibitory control and working memory have been hypothesized to be both a cause and consequence of heavy alcohol use. Adolescence is a critical developmental stage for inhibitory control and working memory, and it is also a stage when individuals are most likely to initiate alcohol use. This study aimed to examine whether inhibitory control and working memory would predict alcohol use and involvement in a group of UK adolescents.

Methods

We recruited 220 (N = 178, female) adolescents, aged between 16 and 18, from eight higher education settings in the Merseyside region of the UK. Alcohol use was examined using the Timeline Follow-Back and involvement (and related problems) using the Adolescent Alcohol Involvement Scale. A reward-based inhibitory control task (Go/No-Go) was used to examine the inhibition and reward sensitivity, and a self-ordered pointing task was used to measure working memory.

Results

Multiple regression demonstrated that neither inhibitory control (b = 0.02 (95% confidence interval (CI): −0.21, 0.24)) nor working memory (b = −0.12 (95% CI: −0.30, 0.07)) were significant predictors of alcohol use (units consumed). Inhibitory control (b = 0.61 (95% CI: 0.12, 1.09), specifically, in the no reward condition and school deprivation (b = 0.67 (95% CI: 0.06, 1.28) significantly predicted alcohol-related problems.

Conclusions

Our findings demonstrated limited evidence that deficits in specific mechanisms of executive functioning (i.e. motor inhibition and working memory) were associated with alcohol-related problems in UK adolescents. This study adds to an increasing body of literature suggesting weak or non-existent links between inhibitory control, working memory and alcohol use.
Risk of precancerous cervical lesions in women using a hormone-containing intrauterine device and other contraceptives: a register-based cohort study from Denmark
Authors: Skorstengaard Malene , Lynge Elsebeth , Napolitano George , Blaakær Jan , Bor Pinar
Published: March 2021

STUDY QUESTION

Is the risk of high-grade precancerous cervical lesions and/or is the risk of lesion progression increased in users of a hormone-containing intrauterine device (HIUD) compared with users of other contraceptive methods.

SUMMARY ANSWER

Women starting use of HIUD had the same subsequent risk of cervical intraepithelial neoplasia 3+ (CIN3+) as copper IUD (CIUD) users, and both groups tended to have lower risks than oral contraceptives (OC) users.

WHAT IS KNOWN ALREADY

HIUDs may cause inflammatory and immunosuppressive changes that may potentially affect the risk of persistent human papillomavirus infection and precancerous cervical lesions.

STUDY DESIGN, SIZE, DURATION

A Danish population-based cohort study was conducted using register data from 2008 to 2011 on 26–50-year-old users of HIUD (n = 60 551), CIUD (n = 30 303), or OC (n = 165 627).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Within each user group, women were divided into two groups; normal cytology or abnormal diagnosis before start of contraceptive use (baseline). Follow-up histology and cytology diagnoses were registered during the 5 years after baseline. Adjusted relative risks (aRR) and 95% CI were calculated for precancerous cervical lesions in HIUD users compared with CIUD and OC users.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with normal cytology at baseline: at follow-up HIUD users had the same risk of CIN3 or higher (3+) as CIUD users; aRR 1.08 (95% CI 0.94–1.22). For the HIUD and CIUD groups compared with OCs, the risks of CIN3+ were lower: aRR 0.63 (95% CI 0.57–0.69) and aRR 0.58 (95% CI 0.52–0.65), respectively. The same was observed for CIN2 risks: aRR 0.86 (95% CI 0.76–0.96) and aRR 0.68 (95% CI 0.58–0.79) for HIUD and CIUD groups, respectively. Women with abnormal diagnosis at baseline: a lower progression risk, except for CIN2+ at baseline, was observed in HIUD users compared with OC users. Similar progression risks were found in HIUD and CIUD users. There were no differences between the three contraceptive groups in persistence or regression of present lesions.

LIMITATIONS, REASONS FOR CAUTION

We adjusted for age, education, and region of residence as a proxy for socio-economic factors. Data on smoking and sexual behavior were not available thus we cannot exclude some differences between the three user groups.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that women may safely use HIUDs.

STUDY FUNDING/COMPETING INTEREST(S)

A.P. Møller Foundation for the Advancement of Medical Science, Else and Mogens Wedell-Wedellborgs Fund, Direktør Emil C. Hertz og Hustru Inger Hertz Fund, and the Fund for Development of Evidence Based Medicine in Private Specialized Practices. EL is principle investigator for a study with HPV-test-kits provided by Roche. The other authors have nothing to declare.

TRIAL REGISTRATION NUMBER

N/A.
Molecular pathways to high-level azithromycin resistance in Neisseria gonorrhoeae
Authors: Laumen J G E , Manoharan-Basil S S , Verhoeven E , Abdellati S , De Baetselier I , Crucitti T , Xavier B B , Chapelle S , Lammens C , Van Dijck C , Malhotra-Kumar S , Kenyon C
Published: March 2021

Background

The prevalence of azithromycin resistance in Neisseria gonorrhoeae is increasing in numerous populations worldwide.

Objectives

To characterize the genetic pathways leading to high-level azithromycin resistance.

Methods

A customized morbidostat was used to subject two N. gonorrhoeae reference strains (WHO-F and WHO-X) to dynamically sustained azithromycin pressure. We tracked stepwise evolution of resistance by whole genome sequencing.

Results

Within 26 days, all cultures evolved high-level azithromycin resistance. Typically, the first step towards resistance was found in transitory mutations in genes rplD, rplV and rpmH (encoding the ribosomal proteins L4, L22 and L34 respectively), followed by mutations in the MtrCDE-encoded efflux pump and the 23S rRNA gene. Low- to high-level resistance was associated with mutations in the ribosomal proteins and MtrCDE efflux pump. However, high-level resistance was consistently associated with mutations in the 23S ribosomal RNA, mainly the well-known A2059G and C2611T mutations, but also at position A2058G.

Conclusions

This study enabled us to track previously reported mutations and identify novel mutations in ribosomal proteins (L4, L22 and L34) that may play a role in the genesis of azithromycin resistance in N. gonorrhoeae.
COVID-19 Impacts on Families of Color and Families of Children With Asthma
Authors: Clawson Ashley H , Nwankwo Cara N , Blair Alexandra L , Pepper-Davis Morgan , Ruppe Nicole M , Cole Ashley B
Published: March 2021

Objective

This cross-sectional study quantified differences in (a) social determinants of health (SDOH) and perceived changes in SDOH during the 2019 novel coronavirus (COVID-19) pandemic and (b) COVID-19 psychosocial impacts across four groups: (a) non-Hispanic White (NHW) parents of children with asthma, (b) Black, Indigenous, or other People of Color (BIPOC) parents of healthy children, (c) BIPOC parents of children with asthma, and (d) NHW parents of healthy children (referent). The NIMHD Framework was used to identify SDOHs that may change for families during COVID-19.

Methods

Parents were recruited via Prolific (N = 321) and completed questions about COVID-19 family impacts on employment, income, access to food and healthcare, and psychosocial functioning, including discrimination. It was hypothesized that NHW families of children with asthma and BIPOC families would endorse greater negative outcomes relative to NHW parents of healthy children.

Results

BIPOC families experienced greater food insecurity and discrimination relative to NHW parents of healthy children. When compared with the NHW healthy group, COVID-19 resulted in greater parent-reported resource losses for both BIPOC groups and greater reductions in healthcare access for both asthma groups. Children with asthma and BIPOC children had greater distress surrounding COVID-19. BIPOC and NHW parents of children with asthma reported greater worries about resource losses due to COVID-19.

Conclusions

The pandemic is widening inequities for BIPOC families, especially for families of children with asthma. These results highlight the need for interventions that address the needs of underserved communities, providing the infrastructure, policies, and supports needed to reduce health inequities during and after COVID-19.
MiniCAFE, a CRISPR/Cas9-based compact and potent transcriptional activator, elicits gene expression in vivo
Authors: Zhang Xin , Lv Sihan , Luo Zhenhuan , Hu Yongfei , Peng Xin , Lv Jie , Zhao Shanshan , Feng Jianqi , Huang Guanjie , Wan Qin-Li , Liu Jun , Huang Hongxin , Luan Bing , Wang Dong , Zhao Xiaoyang , Lin Ying , Zhou Qinghua , Zhang Zhen-Ning , Rong Zhili
Published: March 2021

CRISPR-mediated gene activation (CRISPRa) is a promising therapeutic gene editing strategy without inducing DNA double-strand breaks (DSBs). However, in vivo implementation of these CRISPRa systems remains a challenge. Here, we report a compact and robust miniCas9 activator (termed miniCAFE) for in vivo activation of endogenous target genes. The system relies on recruitment of an engineered minimal nuclease-null Cas9 from Campylobacter jejuni and potent transcriptional activators to a target locus by a single guide RNA. It enables robust gene activation in human cells even with a single DNA copy and is able to promote lifespan of Caenorhabditis elegans through activation of longevity-regulating genes. As proof-of-concept, delivered within an all-in-one adeno-associated virus (AAV), miniCAFE can activate Fgf21 expression in the liver and regulate energy metabolism in adult mice. Thus, miniCAFE holds great therapeutic potential against human diseases.
Four Characteristics of Policing as a Practice
Authors: McGregor Rafe
Published: March 2021

The purpose of this article is three-fold: (1) to provide an analysis of autoethnography as a method in policing research; (2) to distinguish between policing as a practice and policing as an institution; and (3) to outline the characteristics of policing as a practice. I deploy an autoethnographic method to identify the characteristics of the practice of city policing in democracies. These characteristics—heroic struggle, edgework, absolute sacrifice, and worldmaking—draw attention to a crucial mismatch between policing as a practice and policing as an institution. I conclude by suggesting ways in which the characteristics of the practice can provide a firm foundation for further research into the contemporary problems of policing as an institution.
Efficacy and safety of a selective URAT1 inhibitor SHR4640 in Chinese subjects with hyperuricaemia: a randomized controlled phase II study
Authors: Lin Yanwei , Chen Xiaoxiang , Ding Huihua , Ye Ping , Gu Jieruo , Wang Xiaoxia , Jiang Zhenyu , Li Detian , Wang Zhongming , Long Wubin , Li Zhijun , Jiang Gengru , Li Xiaomei , Bi Liqi , Jiang Lindi , Wu Jian , Guo Lian , Cai Xiaoyan , Lu Xin , Chen Qinkai , Chen Hong , Peng Ai , Zuo Xiaoxia , Ning Rui , Zhang Zhe , Tai Yanfei , Zhang Tao , Bao Chunde
Published: March 2021

Objective

To evaluate the efficacy and safety of SHR4640, a highly selective urate transporter 1 inhibitor, in Chinese subjects with hyperuricaemia.

Methods

This was a randomized double-blind dose-ranging phase II study. Subjects whose serum uric acid (sUA) levels were ≥480 µmol/l with gout, ≥480 µmol/l without gout but with comorbidities, or ≥540 µmol/l were enrolled. Subjects were randomly assigned (1:1:1:1:1) to receive once daily 2.5 mg, 5 mg, 10 mg of SHR4640, 50 mg of benzbromarone or placebo, respectively. The primary end point was the proportion of subjects who achieved target sUA level of ≤360 µmol/l at week 5.

Results

99.5% of subjects (n = 197) were male and 95.9% of subjects had gout history. The proportions of subjects who achieved target sUA at week 5 were 32.5%, 72.5% and 61.5% in the 5 mg, 10 mg SHR4640 and benzbromarone groups, respectively, significantly higher than the placebo group (0%; P < 0.05 for 5 mg and 10 mg SHR4640 group). The sUA was reduced by 32.7%, 46.8% and 41.8% at week 5 with 5 mg, 10 mg SHR4640 and benzbromarone, respectively, vs placebo (5.9%; P < 0.001 for each comparison). The incidences of gout flares requiring intervention were similar among all groups. Occurrences of treatment-emergent adverse events (TEAEs) were comparable across all groups, and serious TEAEs were not reported.

Conclusions

The present study indicated a superior sUA-lowering effect and well tolerated safety profile after 5-week treatment with once-daily 5 mg/10 mg of SHR4640 as compared with placebo in Chinese subjects with hyperuricaemia.

Trial registration

ClinicalTrials.gov number, NCT03185793
Evaluation of a Novel Ostomy Barrier Ring with Assisted Flow for Individuals with an Ileostomy
Authors: Quigley Mary , Hannigan Ailish , Dowling Catherine , Stuart AnneMarie , McGovern Siobhan , Untoy Larry , Joyce Myles , Larkin John , Kavanagh Dara
Published: March 2021

OBJECTIVE

To determine the performance and user experience of a novel ostomy barrier ring over a 4-week period.

METHODS

This single-arm investigation conducted across three clinical sites included 25 adult participants with an ileostomy for 3 months or longer. The participants used their standard ostomy pouching appliance along with a novel barrier ring for a period of 4 weeks. Skin condition was assessed using the Ostomy Skin Tool. Change in skin condition over the study period was recorded for each participant. The participants’ experience in using the novel barrier ring was measured using a five-point Likert-type scale.

RESULTS

Twenty of the 25 participants (80%) completed the trial. Of those participants, the median Ostomy Skin Tool score at both the beginning (range, 0–8) and end was 0 (range, 0–6). In terms of skin condition, 7 participants experienced an improvement in skin condition, 11 experienced no change, and 2 got worse. A median score of 5 out of 5 was recorded for all questions relating to user experience.

CONCLUSIONS

Although not statistically significant, there was a clear trend toward improvements in peristomal skin condition using the novel barrier ring, even for participants who were already using a barrier ring. User feedback was positive with respect to comfort, device handling, and the perception of the device’s ability to protect the skin. Further, most participants who already used a barrier ring indicated that the novel barrier ring would result in a longer wear time.