bluuebunny/crossref_metadata_2025 huggingface dataset:
A new validated open-source numerical tool for the evaluation of the performance of wind-assisted ship propulsion systems
Authors: Charlou Moran , Babarit Aurélien , Gentaz Lionel
Published: August 2023

Wind propulsion is envisioned as one of the solutions for the decarbonisation of maritime transport, as it offers high efficiency in terms of primary energy comsumption. Many wind propulsion systems already exist at various development stages, but the uncertainties over their performance is a strong obstacle to their adoption by ship owners. This paper presents a general method for the assessment of steady and unsteady performances of wind- propelled ships with 6 degrees of freedom, as implemented in the open-source program xWASP_CN. Inspired by system-based modelling, the method consists in the independent modelling of the forces acting on the ship, as functions of the ship’s 6 degrees of freedom and environmental conditions. An original root-finding algorithm that leverages the specifics of the physical problem to find the steady equilibrium is presented. The method works either like a Power Prediction Program (PPP) or like a Velocity Prediction Program (VPP). As a PPP, the forward speed and course are fixed while the required propulsive power, leeway angle, heel, trim and sinkage are solved. As a VPP, only the course is fixed and the attained forward speed, leeway angle, heel, trim and sinkage are solved. This makes the method suitable for both hybrid propulsion and pure wind propulsion. The force models can be semi-empirical (usually requiring very little input data), based on preliminary experimental or numerical results (such as forward resistance curves, lift/drag coefficients and frequency-domain sea-keeping coefficients), or full-fledged flow solvers (e.g. potential theory, CFD). Thus the method is suitable for all design stages as each force can be modelled with several levels of accuracy depending on the input data available. Comparisons of an intermediate-level model with experiments on a 18-ft catamaran fitted with a Flettner rotor and a water turbine show good agreement for steady-state results.
Impact of Increased Activated Protein-C Resistance, Decreased
Antithrombin III Activity and Hypocomplementemia on the Gestational Outcomes of
Pregnancies with MTHFR Polymorphisms
Authors: Fadiloglu Erdem , Donmez Hanife Guler , Beksac Kemal , Beksac Mehmet Sinan
Published: August 2023

Objective To evaluate the impact of increased Activated Protein C (APC)
resistance, decreased antithrombin III activity and hypocomplementemia on the
pregnancy outcomes of the patients with methylentetrahydrofolate reductase
(MTHFR) polymorphisms.

Methods This study was composed of 83 pregnancies with MTHFR
polymorphisms. Increased APC resistance, decreased antithrombin III activity and
hypocomplementemia were accepted as risk factors for poor gestational
outcome.

Results Having at least one risk factor resulted in significantly higher
rates of “APGAR score of<7” at the first ten minutes
(p=0.009). Composite adverse outcome rate was also higher in patients
with at least one of the defined risk factors despite lack of statistical
significance (p=0.241). Rate of newborn with an “APGAR score
of<7” at first ten minutes was significantly higher at patients
with hypocomplementemia (p=0.03).

Conclusion Hypocomplementemia is a risk factor for poor gestational
outcome in pregnancies with MTHFR polymorphisms.
Pedicled Flaps for High-Risk Open Vascular Procedures of the Lower Extremity: An Analysis of The National Surgical Quality Improvement Project Database
Authors: Garvey Shannon R. , Valentine Lauren , Weidman Allan A. , Chen Amy , Nanda Asha D. , Lee Daniela , Lin Samuel J. , Lee Bernard T. , Liang Patric , Cauley Ryan P.
Published: August 2023

Background Use of pedicled flaps in vascular procedures is associated with decreased infection and wound breakdown. We evaluated the risk profile and postoperative complications associated with lower extremity open vascular procedures with and without pedicled flaps.

Methods The American College of Surgeons National Surgical Quality Improvement Program database (2010–2020) was queried for Current Procedural Terminology codes representing lower extremity open vascular procedures, including trunk and lower extremity pedicled flaps. Flap patients were compared with a randomized control group without flaps (1:3 cases to controls). Univariate and multivariate analyses were performed.

Results We identified 132,934 adults who underwent lower extremity open vascular procedures. Concurrent pedicled flaps were rare (0.7%), and patients undergoing bypass procedures were more likely to receive a flap than nonbypass patients (69 vs. 64%, p < 0.0001). Flap patients had greater comorbidities. On univariate analysis, flap patients were more likely to experience wound (p = 0.0026), mild systemic (p < 0.0001), severe systemic (p = 0.0452), and all-cause complications (p < 0.0001). After adjusting for factors clinically suspected to be associated with increased risk (gender, body mass index, procedure type, American Society of Anesthesiologists classification, functional status, diabetes, smoking, and albumin < 3.5 mg/dL), wound (p = 0.096) and severe systemic complications (p = 0.0719) were no longer significantly associated with flap patients.

Conclusion Lower extremity vascular procedures are associated with a high risk of complications. Use of pedicled flaps remains uncommon and more often performed in patients with greater comorbid disease. However, after risk adjustment, use of a pedicled flap in high-risk patients may be associated with lower than expected wound and severe systemic complications.
Thermal Challenges in Dynamic Infrared Thermography Used for Perforator Mapping
Authors: Lin Olivia M. , Hunter-Smith David J. , Rozen Warren M.
Published: August 2023

Background The aim of this study is to investigate the different approaches to thermal challenges, both cold and warm, used in dynamic infrared thermography for reconstructive surgery, and explore whether it affects the success of preoperative perforator mapping.

Methods Literature was collected from Ovid Medline, Embase, PubMed, and Cochrane. The references of the full-text articles located from the original search were also appraised. Thirteen articles were extracted for the final qualitative analysis. A systematic review was then conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

Results Thirteen articles looked at a cold challenge, which included airflow cooling, direct contact cooling, and evaporation-based cooling. Two articles investigated warm challenges. One paper used no challenge, suggesting it unnecessary with a highly sensitive camera. All cold challenges were positively supported by a high level of flap perfusion success and/or a high level of correlation with other forms of investigation.

Conclusion Cold challenges were overall superior to no challenge and warm challenges; however, this conclusion is limited by the small participant size, the possibility of detection bias, and poor methodology detailing. Airflow cooling—specifically, using a desktop fan to blow air for 2 minutes—was noted to likely cause the least discomfort due to a low cooling capacity yet simultaneously maintain effectiveness and allow for a uniform cooling application. Warm challenges showed less conclusive results and were restricted by lack of studies. This topic would benefit from larger scale studies that compare multiple approaches while using standardized equipment to eliminate confounding factors.
Desulfonylative Radical Truce–Smiles Rearrangement Utilizing the Benzimidazoline and Benzimidazolium Redox Couple
Authors: Hasegawa Eietsu , Miyajima Ryo , Okamura Manon , Oomori Kazuki , Iwamoto Hajime , Wakamatsu Kan
Published: August 2023

We have developed protocols for promoting redox reactions utilizing the 2-substituted 1,3-dimethylbenzimidazoline (BIH–R) and benzimidazolium (BI+–R) couples which were applied to the desulfonylative radical Truce–Smiles rearrangement. Expected rearrangement products formed in modest to good yields in these processes, in which added or in situ generated BIH–R serve as electron- and hydrogen-atom-donating reagents or photocatalysts. DFT calculations were carried out to gain the information about the radical intermediates involved in the rearrangement reaction.
Multigram-Scale Synthesis of a gem-Difluoro-Substituted 4,5,6,7-Tetrahydrobenzo[c]thiophen-4-one Heterocycle via Oxidative Chlorination and Radical Smiles Rearrangement
Authors: Jamieson Craig , Henry Martyn C. , Anderson Jack Q.
Published: August 2023

We report an optimized synthetic route towards a functionalized 4,5,6,7-tetrahydrobenzo[c]thiophene heterocycle bearing a gem-difluoromethylene moiety in 4 steps with an overall yield of 43%. The CF2 fragment was incorporated using a building block approach, by coupling an appropriate fluorinated alcohol with a C-3 sulfonyl chloride, synthesized via oxidative chlorination of an exocyclic benzyl thioether. Visible-light-mediated Smiles rearrangement of the resulting fluorosulfonate ester then furnishes the desired fluorinated thiophene scaffold.
Pictorial Essay of Linear Endoscopic Ultrasound Examination of Pancreas Anatomy
Authors: Chavan Radhika , Rajput Sanjay
Published: August 2023

Endoscopic ultrasound (EUS) is a widely used imaging modality for both diagnostic and therapeutic purposes. Understanding the anatomy is crucial during a curved linear EUS examination. Compared with other advanced endoscopic techniques, the learning curve for EUS is longer, and the training facilities for EUS are also not widely available. The interest and enthusiasm for EUS among endoscopists is limited by the long learning curve and the scarcity of training programs. Imaging of the pancreas is the most common indication of EUS examination, and many endoscopist often face difficulty in understanding the anatomy and orientation of the pancreas on linear EUS examination. In this article, we will discuss the problems encountered during linear EUS examination and how to overcome each problem with a station-wise pancreas examination.
Acute Limb Ischemia in COVID-19: A Systematic Review
Authors: Indriani Suci , Amshar Mohamed , Nugraha Raka Aldy , Siddiq Taofan , Adiarto Suko
Published: August 2023

Numerous studies have reported cases of acute limb ischemia (ALI) in coronavirus disease 2019 (COVID-19), along with a sharp increase of ALI incidence during the COVID-19 pandemic. The objective of this study was to analyze the clinical features, treatment strategies, and outcomes in COVID-19 patients who developed ALI. A systematic search was performed in PubMed, ScienceDirect, and Cochrane to identify relevant articles. Variables of interest included ALI location, ALI and COVID-19 severity, concomitant thrombosis, comorbidities/risk factors, coagulation and inflammatory parameters, therapy, outcome, and cause of death. Data extraction and pooling were conducted by two reviewers. Fifty-six articles with a total of 191 subjects were included in the analysis; 78.5% of the subjects were male; mean age was 64.2 years; 94.2% of cases were ALI de novo; 41.1% of the subjects had ALI stage IIB; 82.7% of ALI occurred in the lower limb. The popliteal artery was the most commonly affected artery (48.2% of subjects); 38.1% of the subjects had severe COVID-19; 11.1% had asymptomatic COVID-19, and 15.9% were post-COVID-19; 50.7% of the subjects had hypertension; 12.0% of the subjects had concomitant thrombosis; 98.1% of the subjects had elevated D-dimer, and 83.3% of the subjects had elevated C-reactive protein; 61.9% of the subjects underwent surgical thromboembolectomy, 21.3% underwent conservative treatment, and 8.1% underwent amputation initially. The overall mortality rate and limb amputation rate were 39.3 and 22.4%, respectively; 67.6% of deaths were due to respiratory failure. Our study supports that COVID-19 is associated with hypercoagulability that may trigger the development of ALI, and that ALI is a possible predictor of poor outcome in COVID-19 patients.
A New Concept in Flap Transfers—Transposition and Rotation of Fasciocutaneous and Myocutaneous Flaps
Authors: Govila Ashok
Published: August 2023

A new technique of safely transferring tissues has been tried in three cases. This technique combines the principle of local transposition and rotation flaps in the transfer of fasciocutaneous and myocutaneous flaps, in such a way that the advantages of both the principles are complimented and disadvantages eliminated. The results in the cases treated are being presented.
The Nose—An Unusual Site of Electrical Burn
Authors: Khan Masood H. , Khan Arshad H. , Khan Arif Basir , Murari A.
Published: August 2023

Two case of Electrical burn at an unusual site i.e. the root of the nose are being reported along with their management.
The Radial Forearm Flap
Authors: Kumar P. A. Vinod , Kesavadev K.
Published: August 2023

The radial forearm osteocutaneous flap is recently described single stage method for reconstruction of the thumb. The long term results of the two cases treated by us are being presented. The value of the procedure under Indian conditions has been discussed.
Upper Lip Reconstruction with a Forehead Flap
Authors: Mehdiratta N. K. , Bharti Ajai
Published: August 2023

The use of a midline forehead flap for reconstructing the columella, nostril floor and the upper lip in case of basal cell carcinoma is being presented.
Temporomandibular Joint Ankylosis a Preliminary Report
Authors: Kumar P. A. Vinod
Published: August 2023

A technique to correct the functional and cosmetic deformity in temporomandibular joint ankyloses using costochondral grafts is described. Two cases, one each of a bilateral and unilateral ankyloses is presented to illustrate the results obtained.
Complete Congenital Absence of Nose a Case Report
Authors: Khan M. H. , Khan A. B. , Khan A. H.
Published: August 2023

A case of complete congenital absence of the nose is being reported for its rarity along with the review of literature.
Britain’s ‘favoured response’ to crises: a critical review of existing literature on public inquiries
Authors: Critch Nathan
Published: August 2023

Public inquiries are a crucial part of British governance but academic reflections on them are fragmented, and existing scholarship is underappreciated within wider debates. In this review, I counteract this underappreciation and fragmentation by comprehensively organizing and critiquing this literature for the first time. I conceptualize inquiries literature as organized around the question of inquiry functionality, with inquiries considered either to provide accountability, or to serve the interests of the state. I then explore three limitations within this literature: (1) it often lacks a clear definition of the public inquiry; (2) both views of inquiry functionality are somewhat unconvincing (the first view takes inquiries at face value, while the latter adopts a problematic conception of state power); (3) the literature has methodological limitations which hamper attempts to generalize effectively about inquiries. This suggests that new research on inquiries should be clear in its definitional and sampling choices, engage with contemporary theoretical literature on the (British) state in order to conceptualize inquiry functionality more convincingly, and engage with primary data and novel methodological approaches over light single-case studies in order to establish a solid evidential basis on which to make general claims.
Impact dynamics of a viscous drop containing a particle
Authors: Duan Yangyu , Zhao Weiwei , Chu Chunchun , Feng Yumeng , Zhao Song-Chuan , Thoraval Marie-Jean
Published: August 2023

When a particle is attached under a liquid drop by surface tension, it forms a solid–liquid compound drop. We investigate experimentally the impact dynamics of this compound drop onto a solid surface. After impact, the particle rebounds from the solid surface and rises through the drop. The particle can either remain in the deposited liquid at low impact velocities or separate from the drop above a critical impact velocity. We demonstrate here that as the liquid viscosity increases, this separation threshold transitions from a capillary threshold, characterized by a critical particle Weber number, to a viscous threshold, captured by a critical particle Stokes number. However, the particle can still separate from the drop below this viscous limit if the particle is shifted away from the axis of symmetry before the impact of the compound drop. This shifting is observed experimentally at large falling heights, where the particle is destabilized by the air drag. In addition, we show that the shifting of the particle can also induce an inclination in the vertical liquid jetting, with a tangent of its angle proportional to the shifting distance of the particle. Finally, we confirm the focusing mechanism responsible for this liquid jetting by combining the observations of two synchronized cameras, from side view and bottom view.
Three-dimensional reconstruction of the emission field of the inductively coupled plasma jet
Authors: Ding Fei , Liu Yanming , Jia Jing , Li Xiaoping , Li Jiaxin , Zhao Yingxin , Li Rui
Published: August 2023

Three-dimensional plasma diagnosis is crucial for understanding the distribution of the physical parameters of inhomogeneous plasma. Optical emission spectroscopy (OES) can obtain the electron temperature and density by spectrum lines. The premise of the 3D diagnosis by OES is to obtain the 3D emission field of plasma at different wavelengths. In this paper, we studied how to reconstruct the 3D emission field of the inductively coupled plasma (ICP) jet. The purpose of this work is to provide an imaging basis for the future 3D diagnosis of plasma. Volume tomography can directly reconstruct the 3D emission field by two-dimensional images from multiple perspectives, so it is used to reconstruct the 3D emission field of the ICP jet. During the reconstruction, the Monte Carlo method is used to calculate the weight coefficient. In order to solve the ill-posed linear equations involving a large-size weight matrix fast, we first compared the performance of three inversion algorithms in terms of different aspects and then proposed the multiscale calculation method to reduce the size of the weight matrix. We eventually established a 3D reconstruction system to obtain the 3D emission field of the ICP jets at different powers with 5 mm spatial resolution, based upon which we demonstrated the non-uniform structure of the ICP jet. The re-projection error of the ICP jet reconstructed verifies the high reconstruction accuracy of the proposed method.
Fractal and Wada escape basins in the chaotic particle drift motion in tokamaks with electrostatic fluctuations
Authors: Souza L. C. , Mathias A. C. , Caldas I. L. , Elskens Y. , Viana R. L.
Published: August 2023

The E×B drift motion of particles in tokamaks provides valuable information on the turbulence-driven anomalous transport. One of the characteristic features of the drift motion dynamics is the presence of chaotic orbits for which the guiding center can experience large-scale drifts. If one or more exits are placed so that they intercept chaotic orbits, the corresponding escape basins structure is complicated and, indeed, exhibits fractal structures. We investigate those structures through a number of numerical diagnostics, tailored to quantify the final-state uncertainty related to the fractal escape basins. We estimate the escape basin boundary dimension through the uncertainty exponent method and quantify final-state uncertainty by the basin entropy and the basin boundary entropy. Finally, we recall the Wada property for the case of three or more escape basins. This property is verified both qualitatively and quantitatively using a grid approach.
Machine learning enhanced Hankel dynamic-mode decomposition
Authors: Curtis Christopher W. , Jay Alford-Lago D. , Bollt Erik , Tuma Andrew
Published: August 2023

While the acquisition of time series has become more straightforward, developing dynamical models from time series is still a challenging and evolving problem domain. Within the last several years, to address this problem, there has been a merging of machine learning tools with what is called the dynamic-mode decomposition (DMD). This general approach has been shown to be an especially promising avenue for accurate model development. Building on this prior body of work, we develop a deep learning DMD based method, which makes use of the fundamental insight of Takens’ embedding theorem to build an adaptive learning scheme that better approximates higher dimensional and chaotic dynamics. We call this method the Deep Learning Hankel DMD. We likewise explore how our method learns mappings, which tend, after successful training, to significantly change the mutual information between dimensions in the dynamics. This appears to be a key feature in enhancing DMD overall, and it should help provide further insight into developing other deep learning methods for time series analysis and model generation.
Controlling pulse stability in singularly perturbed reaction-diffusion systems
Authors: Veerman F. , Schneider I.
Published: August 2023

The aim of this paper is to investigate the use of Pyragas control on the stability of stationary, localized coherent structures in a general class of two-component, singularly perturbed, reaction-diffusion systems. We use noninvasive Pyragas-like proportional feedback control to stabilize a singular pulse solution to a two-component, singularly perturbed reaction-diffusion system. We show that in a significant region of parameter space, the control can be adjusted to stabilize an otherwise unstable pulse.
Nonlinear coherent structures of nucleus-acoustic wave excitations in multi-nuclei quantum plasmas with ultra-relativistically degenerate electrons and positrons
Authors: Kolay Debaditya , Dutta Debjit
Published: August 2023

The propagation dynamics of the nucleus-acoustic waves (NAW) in a quantum plasma composed of nondegenerate inertial light nuclei, stationary heavy nuclei, and ultra-relativistically degenerate electrons and positrons has been theoretically investigated within the framework of the Boussinesq equation, which is valid for a bi-directional propagation of a small but finite amplitude limit. The N-soliton solution of the Boussinesq equation is derived using Hirota's method. It is found that positive potential structures exist in the sonic and supersonic regimes, whereas negative potential structures are found to be present in the subsonic regime. Pertinent plasma properties are analyzed for one-, two-, and three-soliton solutions in terms of different parameters. In addition to the typical solitary wave solutions, our findings indicate that the nonlinear NAW has breather structures. The three- and four-soliton solutions are used to construct the elastic interaction solutions of the breather–soliton and breather–breather, respectively. The findings are discussed in the context of ultra-relativistic astrophysical plasmas.
Lattice Boltzmann simulations of flow inside a converging and diverging nozzle with the insertion of single and multiple circular cylinders
Authors: Yadav Mahendra , Yadav Rajendra Singh , Wang Cun-Hai
Published: August 2023

The present study delivers several numerical experiments, conducted on a converging–diverging horizontal nozzle with the insertion of single and multiple circular cylinders. The fluid enters from the inlet wall, strikes the nozzle's and cylinder's walls multiple times, affecting the entire flow region, and, finally, leaves the nozzle through the outlet wall. This entire process leads to many new unseen things. The lattice Boltzmann method with a multiple relaxation time scheme is adopted for all the numerical experiments. The physical parameters that are investigated in the present study are Reinlet, Recylinder, drag and lift coefficients, Mach number (Ma), and pressure difference(Δp). It is found that the position of the circular cylinder affects the transition zone between a steady state and an unsteady state. For every different position, a different transition zone is observed. In the case of the presence of multiple cylinders, the effect of the position of every cylinder counts for the net transition zone. Moreover, the variation in the drag and lift coefficients and pressure difference are represented throughout the study.
A variable stiffness method for pneumatic flexible arms
Authors: Wang Xia , Geng Dexu , Peng He , Xu Wenzhi , Wang Dandan , Zhang Lizhong
Published: August 2023

In this study, a three-degree-of-freedom pneumatic flexible arm with a braking function was designed to overcome the shortcomings of low bearing capacity and insufficient rigidity of existing flexible arms. The braking force was adjusted by controlling the air pressure entering the brake, changing the stiffness of the flexible arm, and enhancing the posture maintainability of the flexible arm. A theoretical model of the braking force and stiffness of a flexible arm was established, and applicable experiments were conducted. The theoretical data were consistent with the experimental results. The braking force linearly increased with the increase of braking pressure, at a brake air pressure of 0.40 MPa. The braking force of a single braking unit reached 276 N. The stiffness nonlinearly increased with an increase in the brake air pressure. At a brake air pressure of 0.4 MPa, the axial stiffness of the flexible arm in the initial state had the highest value of 20 kN/m. The stiffness change in the bending direction of the flexible arm in the spatial bending state was the largest and increased by 12.4 times. The proposed flexible arm exhibited high stiffness and flexible movement; thus, it can be used as a flexible arm to support other end effectors. The proposed variable stiffness method can be practically employed to maintain the posture of flexible robots, which has a high practical value.
Exploring inbreeding dynamics by considering reproductive bound and polygyny
Authors: Choi Jibeom , Park Junpyo
Published: August 2023

Inbreeding is a clinically significant measure of a population dependent on human social structures including the population size or the cultural traits. Here, we propose an expanded and elaborate model to analyze the inbreeding within a population where explicit polygyny and inbreeding bounds are taken into account. Unlike the models presented so far, we implemented biologically realistic assumptions that there is the disproportionate probability of males to reproduce (polygyny) and female reproduction is bounded. Using the proposed model equations, we changed the parameters that represent the polygyny degree, the female reproductive bound correlated to the mutation rate, and the total population size. The disappearance of the polygyny that numerous human societies experienced results in the long-lasting effect of the decreasing inbreeding coefficient. Decreased female reproductive bound correlated with a higher mutation rate reveals similar results. After the effect of each factor is analyzed, we modeled the dynamics of the inbreeding coefficient throughout an imaginary human population where polygyny disappears and late marriage becomes prevalent. In this group, the population size gradually and exponentially increases reflecting the traits of prehistoric human society and rising agricultural productivity. To observe how late and less marriage, the feature of the modern developed society, affects the inbreeding dynamics, the female reproductive bound and the population size were assumed to decrease after the population upsurge. The model can explain the decreasing trend of the prehistoric inbreeding coefficient of the actual human population and predict how the trend will be shifted when traits of modern societies continue.
A peculiar topological Hall effect in noncentrosymmetric ternary carbide GdCoC2
Authors: Xu Yang , Ren Wei , Ma Shengcan , Chen Changcai , Fang Chunsheng , Luo Xiaohua , Mo Zhaojun
Published: August 2023

A peculiar topological Hall effect (THE) is reported in a noncentrosymmetric ternary carbide GdCoC2. The GdCoC2 reveals a magnetic ordering transition from paramagnetic to ferromagnetic state at the Curie temperature TC = 15.6 K, followed by a commensurate-incommensurate phase transition at Tt = 14.1 K. Below Tt, the competition between an external magnetic field and magnetic interactions, including the Dzyaloshinskii–Moriya interaction, would give rise to characteristic spin textures with non-zero scalar spin chirality χijk, or even topologically protected spin configurations like skyrmions, for which the exotic spin-charge coupled phenomena are induced. Besides a large negative magnetoresistance (MR) up to ∼−52% at 14 K, a remarkably sharp topological Hall signal is observed with almost no anomalous Hall resistivity below 10 K. The topological Hall resistivity (ρxyT) of GdCoC2 reaches a maximum value of ∼0.23 μΩ cm at 3 K under μ0H = 0.6 T. The mechanism underlying the exceptional THE with relatively large ρxyT value in GdCoC2 is discussed in detail.
Influence of nozzle geometry on screech instability closure
Authors: Karnam A. , Saleem M. , Gutmark E.
Published: August 2023

The effect of nozzle exit geometry on the triadic interactions between convective Kelvin–Helmholtz instabilities and the quasi-steady shock structure of supersonic jets is discussed in this study. A circular and rectangular nozzle with an aspect ratio (AR) of 2 were evaluated using results from near field acoustics and high-speed Schlieren images. The study investigated different types of screech instabilities in both nozzle configurations, including the multimode instability in rectangular jets. The near field acoustic measurements showed comparable trends in screech staging in both nozzle configurations. The Schlieren results revealed that the standing waves in the jet near field were influenced by the oscillation mode of the jets. The study also explored a new technique of noise visualization from Schlieren images based on near field acoustics and temporal Fourier decomposition. Spatial Fourier decomposition demonstrated that the resonance closure mechanism across both nozzle configurations was dependent on the relative influence of the first two shock cells. Comparisons between the AR 2 and AR 9 jet showed that jet aspect ratio can significantly affect the energy distribution from the triadic interactions.
Thermophoresis of nanoparticles in the transition regime
Authors: Liu Wangwang , Wang Jun , Xia Guodong , Li Zhigang
Published: August 2023

The thermophoresis of nanoparticles suspended in gas is investigated in the transition regime by molecular dynamics simulations. It is found that there exists significant discrepancy between the simulation results and the theoretical predictions for the thermophoretic force, which is attributed to the adsorption of gas molecules on nanoparticles and the gas–particle non-rigid body collisions. By using the effective particle radius, the simulation results and Talbot et al.'s equation could agree with each other in the transition regime. In addition, the effect of the finite system size of the molecular dynamics simulations is non-negligible, and the simulation results modified by effective particle radius can coincide with Phillips' equation quite well. Therefore, for particles of a few nanometers, the non-rigid body collision effect and the adsorption of gas molecules and the effective radius of the nanoparticle under strong gas–particle coupling should be taken into account in the theoretical model. The investigation presented in this paper provides guidance for the application of nanoparticles in aerosol science.
The paramedic–general practitioner relationship: a scoping review
Authors: Petschack Sarah , Lasslett Robert , Ross Linda
Published: August 2023

Background Health services internationally are implementing programs that increase working ties between paramedics and general practitioners (GPs) to reduce unnecessary transport to emergency departments (EDs) and improve access to primary health care. As paramedic involvement in primary health care develops, there is increasing focus on the GP–paramedic collaborative relationship. Resulting issues regarding professional boundaries may occur, as paramedics practice in fields that were previously solely in the GP scope. An effective paramedic-GP working relationship will be an essential foundation to the success of future strategies. Methods A search of three electronic databases was completed (Ovid MEDLINE, Embase Classic + Embase and CINAHL Plus). Eligibility for inclusion required analysis of the relationship between paramedics and GPs. All processes were completed by two independent reviewers. Results After removal of duplicates, 4995 titles were screened by title and/or abstract. After full-text review, 15 studies were included. Five themes were identified that contribute significantly to the strengths and weaknesses of the relationship – the importance of communication, understanding scope of practice, leadership roles, responsibility for patient care and interdisciplinary training. Issues identified included significant variation in the structure of different emergency medical services and varying standards of education requirements for paramedics worldwide. Conclusions There were no published Australian studies that had the primary aim of examining the paramedic–GP relationship. The depth of research on this topic is lacking, despite increased interest over the past decade. The relevance of the international literature to the Australian setting is questionable.
CRISPR/dCas9 DNA methylation editing is heritable during human hematopoiesis and shapes immune progeny
Authors: Saunderson Emily A. , Encabo Hector Huerga , Devis Julie , Rouault-Pierre Kevin , Piganeau Marion , Bell Christopher G. , Gribben John G. , Bonnet Dominique , Ficz Gabriella
Published: August 2023

Aging is associated with an abnormal increase in DNA methylation (DNAm) in human gene promoters, including in bone marrow stem cells. DNAm patterns are further perturbed in hematological malignancies such as acute myeloid leukemia but the physiological significance of such epigenetic changes is unknown. Using epigenetic editing of human stem/progenitor cells (HSPCs), we show that p15 methylation affects hematopoiesis in vivo. We edited the
CDKN2B
(p15) promoter and
ARF
(p14) using dCas9-3A3L and observed DNAm spreading beyond the gRNA location. We find that despite a transient delivery system, DNAm is maintained during myeloid differentiation in vitro, and hypermethylation of the p15 promoter reduces gene expression. In vivo, edited human HSPCs can engraft the bone marrow of mice and targeted DNAm is maintained in HSPCs long term. Moreover, epigenetic changes are conserved and inherited in both myeloid and lymphoid lineages. Although the proportion of myeloid (CD33
+
) and lymphoid (CD19
+
) cells is unaffected, monocyte (CD14
+
) populations decreased and granulocytes (CD66b
+
) increased in mice engrafted with p15 hypermethylated HSPCs. Monocytes derived from p15 hypermethylated HSPCs appear to be activated and show increased inflammatory transcriptional programs. We believe these findings have clinical relevance since we found p15 promoter methylation in the peripheral blood of patients with clonal hematopoiesis. Our study shows DNAm can be targeted and maintained in human HSPCs and demonstrated functional relevance of aberrant DNAm on the p15 locus. As such, other aging-associated aberrant DNAm may impact hematopoiesis in vivo.
Colorful low-emissivity paints for space heating and cooling energy savings
Authors: Peng Yucan , Lai Jian-Cheng , Xiao Xin , Jin Weiliang , Zhou Jiawei , Yang Yufei , Gao Xin , Tang Jing , Fan Lingling , Fan Shanhui , Bao Zhenan , Cui Yi
Published: August 2023

Space heating and cooling consume ~13% of global energy every year. The development of advanced materials that promote energy savings in heating and cooling is gaining increasing attention. To thermally isolate the space of concern and minimize the heat exchange with the outside environment has been recognized as one effective solution. To this end, here, we develop a universal category of colorful low-emissivity paints to form bilayer coatings consisting of an infrared (IR)-reflective bottom layer and an IR-transparent top layer in colors. The colorful visual appearance ensures the aesthetical effect comparable to conventional paints. High mid-infrared reflectance (up to ~80%) is achieved, which is more than 10 times as conventional paints in the same colors, efficiently reducing both heat gain and loss from/to the outside environment. The high near-IR reflectance also benefits reducing solar heat gain in hot days. The advantageous features of these paints strike a balance between energy savings and penalties for heating and cooling throughout the year, providing a comprehensive year-round energy-saving solution adaptable to a wide variety of climatic zones. Taking a typical midrise apartment building as an example, the application of our colorful low-emissivity paints can realize positive heating, ventilation, and air conditioning energy saving, up to 27.24 MJ/m
2
/y (corresponding to the 7.4% saving ratio). Moreover, the versatility of the paint, along with its applicability to diverse surfaces of various shapes and materials, makes the paints extensively useful in a range of scenarios, including building envelopes, transportation, and storage.
Evolutionary history of MEK1 illuminates the nature of deleterious mutations
Authors: Andrianova Ekaterina P. , Marmion Robert A. , Shvartsman Stanislav Y. , Zhulin Igor B.
Published: August 2023

Mutations in signal transduction pathways lead to various diseases including cancers. MEK1 kinase, encoded by the human
MAP2
K1
gene, is one of the central components of the MAPK pathway and more than a hundred somatic mutations in the
MAP2
K1
gene were identified in various tumors. Germline mutations deregulating MEK1 also lead to congenital abnormalities, such as the cardiofaciocutaneous syndrome and arteriovenous malformation. Evaluating variants associated with a disease is a challenge, and computational genomic approaches aid in this process. Establishing evolutionary history of a gene improves computational prediction of disease-causing mutations; however, the evolutionary history of MEK1 is not well understood. Here, by revealing a precise evolutionary history of MEK1, we construct a well-defined dataset of MEK1 metazoan orthologs, which provides sufficient depth to distinguish between conserved and variable amino acid positions. We matched known and predicted disease-causing and benign mutations to evolutionary changes observed in corresponding amino acid positions and found that all known and many suspected disease-causing mutations are evolutionarily intolerable. We selected several variants that cannot be unambiguously assessed by automated prediction tools but that are confidently identified as “damaging” by our approach, for experimental validation in
Drosophila
. In all cases, evolutionary intolerant variants caused increased mortality and severe defects in fruit fly embryos confirming their damaging nature. We anticipate that our analysis will serve as a blueprint to help evaluate known and novel missense variants in MEK1 and that our approach will contribute to improving automated tools for disease-associated variant interpretation.
Milton assembles large mitochondrial clusters, mitoballs, to sustain spermatogenesis
Authors: Li Andy Y. Z. , Di Ying , Rathore Sumaera , Chiang Ason C.-Y. , Jezek Jan , Ma Hansong
Published: August 2023

Mitochondria are dynamic organelles that undergo frequent remodeling to accommodate developmental needs. Here, we describe a striking organization of mitochondria into a large ball-like structure adjacent to the nucleus in premeioticDrosophila melanogasterspermatocytes, which we term “mitoball”. Mitoballs are transient structures that colocalize with the endoplasmic reticulum, Golgi bodies, and the fusome. We observed similar premeiotic mitochondrial clusters in a wide range of insect species, including mosquitos and cockroaches. Through a genetic screen, we identified that Milton, an adaptor protein that links mitochondria to microtubule-based motors, mediates mitoball formation. Flies lacking a 54 amino acid region in the C terminus of Milton completely lacked mitoballs, had swollen mitochondria in their spermatocytes, and showed reduced male fertility. We suggest that the premeiotic mitochondrial clustering is a conserved feature of insect spermatogenesis that supports sperm development.
Unusual magnetotransport in twisted bilayer graphene from strain-induced open Fermi surfaces
Authors: Wang Xiaoyu , Finney Joe , Sharpe Aaron L. , Rodenbach Linsey K. , Hsueh Connie L. , Watanabe Kenji , Taniguchi Takashi , Kastner M. A. , Vafek Oskar , Goldhaber-Gordon David
Published: August 2023

Anisotropic hopping in a toy Hofstadter model was recently invoked to explain a rich and surprising Landau spectrum measured in twisted bilayer graphene away from the magic angle. Suspecting that such anisotropy could arise from unintended uniaxial strain, we extend the Bistritzer–MacDonald model to include uniaxial heterostrain and present a detailed analysis of its impact on band structure and magnetotransport. We find that such strain strongly influences band structure, shifting the three otherwise-degenerate van Hove points to different energies. Coupled to a Boltzmann magnetotransport calculation, this reproduces previously unexplained nonsaturating

B
2

magnetoresistance over broad ranges of density near filling

ν
=
±
2

and predicts subtler features that had not been noticed in the experimental data. In contrast to these distinctive signatures in longitudinal resistivity, the Hall coefficient is barely influenced by strain, to the extent that it still shows a single sign change on each side of the charge neutrality point—surprisingly, this sign change no longer occurs at a van Hove point. The theory also predicts a marked rotation of the electrical transport principal axes as a function of filling even for fixed strain and for rigid bands. More careful examination of interaction-induced nematic order versus strain effects in twisted bilayer graphene could thus be in order.
Association measures for collocation extraction
Authors: Su Qi , Gu Chen , Liu Pengyuan
Published: August 2023

In this study, we propose a new evaluation scheme to assess the strengths and limitations of collocation extraction measures and explore type-sensitive methods for extracting collocations. We introduced the pooling strategy widely used in Information Retrieval and automated the evaluation process using online dictionaries. Sixteen well-known metrics are evaluated based on their effectiveness and then distributional and linguistic compared. The results show that Group A methods (e.g. z-score, Dice, PMI) are more effective in extracting low-frequency collocations with relatively small extraction scales. In contrast, Group B methods (e.g. t-test, LMI, LLR) perform better at finding high-frequency collocations, most of which outperform Group A methods as the extraction scale increases. Moreover, Group A prefers NN collocations, while Group B identifies collocations with a wide range of syntactic structures. This study provides suggestions for studies to identify hybrid extraction methods as well as for language educators and dictionary compilers.
Generation of a coherent squeezed-like state defined with the Lie–Trotter product formula using a nonlinear photonic crystal
Authors: Azuma Hiroo
Published: August 2023

In this paper, we investigate how to generate coherent squeezed-like light using a nonlinear photonic crystal. Because the photonic crystal reduces the group velocity of the incident light, if it is composed of a material with a second-order nonlinear optical susceptibility

χ

(
2
)

, the interaction between the nonlinear material and the light passing through it strengthens and the quantum state of the emitted light is largely squeezed. Thus, we can generate a coherent squeezed-like light with a resonating cavity in which the nonlinear photonic crystal is placed. This coherent squeezed-like state is defined with the Lie–Trotter product formula and its mathematical expression is different from those of conventional coherent squeezed states. We show that we can obtain this coherent squeezed-like state with a squeezing level 15.9 dB practically by adjusting the physical parameters for our proposed method. Feeding the squeezed light whose average number of photons is given by one or two into a beam splitter and splitting the flow of the squeezed light into a pair of entangled light beams, we estimate their entanglement quantitatively. This paper is a sequel to Azuma (2022 J. Phys. D: Appl. Phys.
55 315106).
An improved graph convolutional networks for fault diagnosis of rolling bearing with limited labeled data
Authors: Xiao Xiangqu , Li Chaoshun , Huang Jie , Yu Tian , Wong Pak Kin
Published: August 2023

Rolling bearings are essential parts of rotating equipment. Due to their unique operating environment, bearings are vulnerable to failure. Graph neural network (GNN) provides an effective way of mining relationships between data samples. However, various existing GNN models suffer from issues like poor graph-structured data quality and high computational consumption. Moreover, the available fault samples are typically insufficient in real practice. Therefore, an improved graph convolutional network (GCN) is proposed for bearing fault diagnosis with limited labeled data. This method consists of two steps: graph structure data acquisition and improved graph convolution network building. Defining edge failure thresholds simplifies the generated weighted graph-structured data, thereby enhancing data quality and reducing training computation costs. Improvements to standard GCNs can effectively aggregate data features of different receptive field sizes without noticeably raising the computational complexity of the model. Experiments with limited labeled data are conducted on two public datasets and an actual experimental platform dataset to verify the superiority of the proposed method. In addition, experiments on imbalanced datasets also fully demonstrate the robustness of the proposed method.
Separation of multi-echo overlapping ultrasonic signals for increasing the axial resolution using a neural network
Authors: Li Dongxun , Chen Zhaoqi , Zhang Yulong , Zhao Sheng , Liu Wangyu
Published: August 2023

The ultrasonic pulse-echo method plays a significant role in ultrasonic thickness measurement. However, when the measured thickness is relatively thin, it is universal for the reflected ultrasonic echoes to overlap in the time domain which constrains the achievable resolution using the conventional pulse-echo method. A deep learning network for multi-echo overlapping ultrasonic signals separation under the constraint of an ultrasonic transducer with specific center frequency and bandwidth was proposed to enhance the axial resolution. With this model, the adaptive separation of overlapping signals with an unknown number of echoes is achieved by extracting detailed features of the overlapping signals. An overlapping signal training dataset based on truncated Nakagami functions is constructed to train the network. Simulation experiments under different degrees of overlap and noise levels were conducted for the performance analysis. Simulation results manifested the performance advantage of proposed separation method over some traditional separation methods. Further, ultrasonic thickness measurement experiments were performed on thin-walled aluminum alloy plates with various thicknesses, demonstrating feasibility and practicability of the network over traditional separation methods.