bluuebunny/crossref_metadata_2025 huggingface dataset:
On molecular unmixedness between the ejected original and entrained ambient fluids in a turbulent jet
Authors: Mi Jianchun , Wu Mengwei , Xu Minyi
Published: July 2023

The present study investigates the molecular unmixedness between the injected and entrained fluids in a turbulent jet as well as its dependence on the initial conditions. This unmixedness can be quantified as the parameter of molecular segregation between the ejecting “fuel” fluid (A) and the entrained “oxidizer” fluid (B), defined by α≡cAcB¯/C¯AC¯B (overbar denotes time-averaging). For the first time, an expression of the parameter has been derived for the two-fluid mixing in a heated turbulent nonreactive jet. That is, α=−θ2¯/Θo−Θ¯Θ¯−Θa, where Θo and Θa denote the ejected “warm” and entrained “cold” fluid temperatures, whereas Θ and θ are the instantaneous and fluctuating temperatures of the local fluid mixture. This expression of α is well validated by comparing the measured natural-gas flames from a smooth-contraction nozzle with those from a long-pipe nozzle. Moreover, the jet-nozzle configuration is found to show a strong effect on α. Likewise, the jet density ratio (Rρ) is a highly influential factor: e.g., an increase in Rρ reduces α substantially. In contrast, the effect of the jet-exit Reynolds number is less significant. In the present paper, we try to explain these observations.
Designing mechanosensitive molecules from molecular building blocks: A genetic algorithm-based approach
Authors: Blaschke Matthias , Pauly Fabian
Published: July 2023

Single molecules can be used as miniaturized functional electronic components, when contacted by macroscopic electrodes. Mechanosensitivity describes a change in conductance for a certain change in electrode separation and is a desirable feature for applications such as ultrasensitive stress sensors. We combine methods of artificial intelligence with high-level simulations based on electronic structure theory to construct optimized mechanosensitive molecules from predefined, modular molecular building blocks. In this way, we overcome time-consuming, inefficient trial-and-error cycles in molecular design. We unveil the black box machinery usually connected to methods of artificial intelligence by presenting all-important evolutionary processes. We identify the general features that characterize well-performing molecules and point out the crucial role of spacer groups for increased mechanosensitivity. Our genetic algorithm provides a powerful way to search chemical space and to identify the most promising molecular candidates.
Integrating seed microbiome knowledge into restoration and ex situ conservation of native Australian plants
Authors: Mertin Allison A. , Philpott Merize , Blackall Linda L. , French Kris , Liew Edward C. Y. , van der Merwe Marlien M.
Published: July 2023

Context Seeds harbour a diversity of microbes, which in some plants aid with germination and establishment. Seeds form a critical part in the lifecycle of plants and a role in many conservation and restoration activities. Aims Because this is an emerging field in seed biology, we aim to highlight the key research gaps of interest to seed on the basis of restoration and ex situ conservation. Methods We identify knowledge gaps associated with the seed endophytic microbiome of native Australian plants through undertaking a literature review. Additionally, culturing methods were used to identify the fungal seed endophytes of five native Australian species. Key results We identified a diversity of taxa within the native seed and show three taxa that are common to all study hosts. Sampling seed from additional hosts at a site and additional sites of a host species showed new fungal diversity. Our literature review showed that little information is available on native seed microbiomes and we identified four key areas where research gaps exist, linking with seed-based restoration practices. Conclusions We provide evidence that there is a complex and diverse seed microbiome within some Australian native plants and suggest ways that it could be integrated into restoration and conservation practices. Implications We propose that by taking into consideration the presence of a seed microbiome and its potential impacts on plant health, seed microbiomes could be used as one method to restore microbial diversity into an ecosystem and to contribute to the seedling microbiome and plant health at restored sites.
Achievements, Challenges, and Future Perspective in Managing the Hessian Fly,
Mayetiola destructor
, in the USA
Authors: Chen Ming-Shun , Liu Xuming
Published: July 2023

The Hessian fly,
Mayetiola destructor
(Say) (Diptera: Cecidomyiidae), is an insect pest that causes serious damage and yield loss to wheat (
Triticum aestivum
L. (Family:
Poaceae
)) and barley (
Hordeum vulgare
) in the USA as well as other wheat-growing countries in the world. Hessian fly is thought to be originated in the Fertile Crescent region of the Middle East, from where it has spread to major wheat- and barley-producing countries including Europe, the USA, West Asia, and North Africa. In the USA, outbreaks of Hessian fly result in ~5% yield losses each year and with reduced grain quality from fly-damaged plants. Through continuous research and development, various controlling measures for integrated pest management against the Hessian fly pest have been developed. This case report summarizes the achievements in controlling this insect pest in the past century and new challenges arising due to changes in climate, cultural practices, and farming objectives.

Information

© The Authors 2023
Micromechanical vibro-impact systems: a review
Authors: Tsai Chun-Pu , Li Wei-Chang
Published: July 2023

Spurred by the invention of the tapping-mode atomic force microscopy three decades ago, various micromechanical structures and systems that utilize parts with mechanical impact have been proposed and developed since then. While sharing most of the dynamical characteristics with macroscopic vibro-impact systems and benefiting from extensive theories developed, microscale counterparts possess higher percentage of surface force, higher resonance frequency and Q, and more prominent material and structural nonlinearities, all of which lead to unique features and in turn useful applications not seen in macroscopic vibro-impact systems. This paper will first present the basics of vibro-impact systems and techniques used for analyzing their nonlinear behaviors and then review the contact force modeling and numerical analysis tools. Finally, various applications of microscale vibro-impact systems will be reviewed and discussed. This review aims to provide a comprehensive picture of MEMS vibro-impact systems and inspire more innovative applications that take full advantage of the beauty of nonlinear vibro-impact dynamics at the microscale.
Noise analysis and modeling for a digital control architecture for Lissajous frequency-modulated MEMS gyroscope with amplitude-modulated readout
Authors: Wang Xuetong , Zheng Xudong , Shen Yaojie , Xia Chenhao , Tong Wenyuan , Jin Zhonghe , Ma Zhipeng
Published: July 2023

We report a digital control architecture that demodulates both amplitude-modulated (AM) and frequency-modulated (FM) rate information simultaneously from a gyroscope working in Lissajous frequency-modulated (LFM) mode. The angular rate information is derived from both quadrature (X and Y) resonance modes of the gyroscope simultaneously. A noise model for the AM signal processing channel of the LFM gyroscope is built, analyzed and compared with that of a conventional AM gyroscope, which shows that methods to improve the performance of the conventional AM gyroscope can also be applied to the AM signal processing channel of the LFM gyroscope. The angular rate output obtained from the AM information of the LFM gyroscope has better noise characteristics, which therefore supplements the low precision inadequacy of the FM signal channel of the LFM mode. Tests on the same gyroscope working in different control architectures are conducted. The angle random walk (ARW) and bias instability (BI) of the AM channel of the proposed architecture are 0.51 deg √h−1 and 1.8 deg h−1, respectively, which are better than the results obtained from the FM channel in the same architecture, with values of 0.99 deg √h−1 and 4.3 deg h−1, respectively. Also ARW amd BI of the same gyroscope working in conventional AM mode is 0.50 deg √h−1 and 5.2 deg h−1, respectively.
First multiplexed electrochemical wax-on-plastic chip: PNA/GO interface integration for DNA detection
Authors: Das Prabhangshu Kumer , Adil Omair , Shamsi Mohtashim Hassan
Published: July 2023

This study presents the fabrication of the first multiplexed wax-on-plastic electrochemical chip with low-temperature sintering of the conductive layers. A total of 169 sensing electrodes (1.2 mm diameter each) were printed on a wax-patterned plastic substrate using silver inkjet printing. Fidelity of the device was confirmed using optical and electrical techniques. The sensing electrodes were modified using graphene oxide (GO) ink and peptide nucleic acid (PNA) probes through simple drop-casting. The PNA/GO interface on the multiplexed chip was used to detect DNA using differential pulse voltammetry, which records the electrons transfer from the diffusion of a soluble redox probe. The PNA/GO interface was then tested against a target concentration, target size, and mismatched target. The response of the DNA-PNA duplex on the surface was additionally compared with the prehybridized duplex, and the lower affinity of the duplexes for the GO surface was confirmed by removing Mg2+. The interface was responsive to such variables at attomolar concentrations. The low volume of the target (300 nL) at that concentration level demonstrated the chip sensitivity with only 18 target molecules on the surface.
Optically transparent conformal ultra-broadband metamaterial absorber based on ITO conductive film
Authors: Ji Shijun , Ren Hailin , Zhang Chenguang , Zhao Ji , Wu Han , Dai Handa
Published: July 2023

An optically transparent metamaterial absorber with polarization insensitivity and wide-angle absorption is proposed. The absorber, which consists of an indium tin oxide resistive film and a low-loss substrate, is optically transparent and conformal. By tuning the reflection response of the frequency-selective surface and the thickness of the spacer layer, the whole structure achieves an absorption of more than 97% in the range of 6.54–18.66 GHz. Numerical simulation results show that the absorber can still maintain an absorption rate of more than 85% in a wide range of oblique incidence angles from 0° to 60°. In addition, the intrinsic physical mechanism of the absorber is elucidated using the impedance matching theory and the distribution of surface currents. The ratio of dielectric loss and ohmic loss is also quantitatively analyzed. Finally, the reflection and transmission coefficients of the sample were measured in a microwave anechoic chamber, which showed a good agreement with the simulation results. This design uses a low-resistivity resistive film as a frequency-selective surface, which was rarely involved in previous studies, and provides a new idea for future design and application.
A magnetic skyrmion diode based on potential well inducting effect
Authors: Xu Min , Chen Wenlong , Chen Yuliang , Hu Changjing , Zhang Zhiyu , Jiang Guiqian , Zhang Jinyu
Published: July 2023

Magnetic skyrmions have great potential in the application of spintronic devices due to their stable topologically protected spin configuration. To meet the needs of spintronic device design, it is necessary to manipulate the movement of the magnetic skyrmions. Here we propose a skyrmion diode based on potential well induced skyrmion motion through theoretical calculations. The potential well is generated by the voltage-controlled magnetic anisotropy (VCMA) gradient. By utilizing the induction of the potential well as well as the skyrmion Hall effect (SkHE), the velocity and trajectory of the skyrmions can be controlled and the forward pass and reverse cutoff functions of diode-like devices have been realized. Furthermore, we report the dynamics of current-driven skyrmions in a racetrack with locally applied VCMA. Under the influence of the SkHE, the difference in dynamic behavior between forward and reverse motion of the skyrmions is obvious, and the potential well can produce different pinning, depinning and annihilating effects on forward and reverse moving skyrmions. Our results can be beneficial for the design and development of magnetic skyrmion diodes.
Generalizing Thiele equation
Authors: Kim Bom Soo
Published: July 2023

We generalize the Thiele equation with a transverse velocity to the skyrmion motion described by the collective coordinate of magnetization vector. It is applied to investigate a significant disparity in the existing data sets of skyrmion and antiskyrmion Hall angles. Our analysis further reveals interesting differences of these Hall angles near the angular momentum compensation point. We identify a possible physical quantity that is responsible for the disparity.
Higher energy density of MoSe2/polyaniline capsule nanospheres for enhanced performance supercapacitor
Authors: Zhang Huimin , He Geping , Zheng Donghao , HuangFu Huijun , Li Yanxia , Mi Yuanmei , Wu Minye , Yuan Hudie
Published: July 2023

It is very important to develop novel nanocomposites as electrode materials for supercapacitors (SCs). MoSe2 porous nanospheres were prepared by one-step hydrothermal method, and polyaniline (PANI) nanosheets were grown in situ to obtain MoSe2/PANI capsule nanospheres (CNs). By changing the amount of aniline, it was found that MoSe2/PANI-16 CNs had the best electrochemical performance, and a high specific capacitance of 753.2 F g−1 was obtained at a current density of 1 A g−1. In addition, the interface electron transport path was clarified that a C–Mo–Se bridge bonds may be formed for rapid electron transfer. The reaction kinetics was also explored. The large specific surface areas of MoSe2/PANI CNs provided more reactive sites, so that the contribution of pseudocapacitance was much larger than diffusion capacitance. The assembled MoSe2/PANI//activated carbon asymmetric supercapacitor has a energy density of 20.1 Wh kg−1 at a power density of 650 W kg−1. These results indicate that the MoSe2/PANI CNs are a promising electrode material.
Automatic segmentation of rectal tumors from MRI using multiscale densely connected convolutional neural network based on attention mechanism
Authors: Zhang Kenan , Yang Xiaotang , Cui Yanfen , Zhao Jumin , Li Dengao
Published: July 2023

Rectal cancer is one of the most common malignancies in the gastrointestinal tract. Currently, magnetic resonance imaging has become a vital tool in diagnosing and treating patients with rectal cancer. Notably, early diagnosis of rectal cancer can help improve patient survival rate; however, the clinical expertize of physicians is a limiting factor. Therefore, we propose an attention-based multiscale densely connected convolutional neural network based on an attention mechanism to improve the accuracy of diagnosis by automatically segmenting rectal tumors from two-dimensional (2D) magnetic resonance images (MRI) using computer-aided diagnostic techniques. First, to address the inability of U-Net (a classical segmentation network for medical images) and extract rich semantic features and the inconsistent shape and size of tumors between different patients, we replace the conventional convolutional blocks in the U-Net network with multiscale densely connected convolutional blocks. Second, to make the network focus better on global contextual information, we add central blocks with atrous convolution in the final coding layer or the last coding layer. Finally, we add a hybrid attention mechanism to each decoder module to help the model focus on the features of the rectal tumor region. We validated the effectiveness of the proposed method using 3773 2D MRI datasets from 572 patients. The sensitivity, specificity, Dice correlation coefficient, and Hausdorff distance of MRI rectal tumor segmentation were 85.47%, 86.35%, 94.71%, and 7.88 mm, respectively. The results showed that the proposed method outperforms conventional approaches. Moreover, the proposed method has better segmentation results in the rectal tumor segmentation task and can provide physicians with the second-most important clinical diagnostic opinion.
Statistical models of complex brain networks: a maximum entropy approach
Authors: Dichio Vito , De Vico Fallani Fabrizio
Published: July 2023

The brain is a highly complex system. Most of such complexity stems from the intermingled connections between its parts, which give rise to rich dynamics and to the emergence of high-level cognitive functions. Disentangling the underlying network structure is crucial to understand the brain functioning under both healthy and pathological conditions. Yet, analyzing brain networks is challenging, in part because their structure represents only one possible realization of a generative stochastic process which is in general unknown. Having a formal way to cope with such intrinsic variability is therefore central for the characterization of brain network properties. Addressing this issue entails the development of appropriate tools mostly adapted from network science and statistics. Here, we focus on a particular class of maximum entropy models for networks, i.e. exponential random graph models, as a parsimonious approach to identify the local connection mechanisms behind observed global network structure. Efforts are reviewed on the quest for basic organizational properties of human brain networks, as well as on the identification of predictive biomarkers of neurological diseases such as stroke. We conclude with a discussion on how emerging results and tools from statistical graph modeling, associated with forthcoming improvements in experimental data acquisition, could lead to a finer probabilistic description of complex systems in network neuroscience.
Angular time delay in quantum mechanical scattering
Authors: Zahn Jochen
Published: July 2023

We apply Brunetti and Fredenhagen’s concept of the time of occurrence of an event in quantum mechanics Brunetti and Fredenhagen (2002 Phys. Rev. A
66 044101) to the example of scattering off a spherical potential. Thereby, we re-derive the expression of Froissart, Goldberger, and Watson for the angular time delay Froissart et al (1963 Phys. Rev.
131 2820), clarifying some conceptual issues with their derivation. We also present an elementary re-derivation of the ‘space shift’ (essentially the impact parameter) defined in the quantum mechanical context by the same authors. We clarify the relation of both quantities to their classical counterparts in the context of the WKB approximation. As an example, we apply the concepts to scattering at a hard sphere. We find pronounced peaks in the both the time delay and the space shift at the minima of intensity in the forward diffraction region for short wavelength scattering and discuss whether these could in principle be observable.
Modulating anti-dark vector solitons
Authors: Peng Yangyang , Xu Guangyu , Zhang Keyun , Liao Meisong , Fang Yongzheng , Zhou Yan
Published: July 2023

Theoretical analysis of the modulation of anti-dark vector solitons is conducted in this work. The simulation depends on a single-mode optical fiber out-cavity modulation system model that works at 1 μm. The anti-dark vector soliton’s initial state is assumed to be polarization-/group-velocity-locked, with same/different central wavelengths in orthogonally polarized directions. After soliton parameter modulation, modulated anti-dark vector solitons at the output port will demonstrate different properties in orthogonal directions. For example, two symmetrically located frequency peaks always exist for output orthogonal modes when the input state is polarization-locked. And a dual-wavelength anti-dark vector soliton with temporal pulse oscillation can be generated by changing the projection angle with the help of a polarization beam splitter, when the input vector soliton’s group-velocity is locked. These modulation results are instructive for the study of out-cavity modulating optical fiber vector soltions with different pulsed properties.
Non-Gaussian approach: Withstanding loss and noise of multi-scattering underwater channel for continuous-variable quantum teleportation
Authors: Wu 吴 Hao 昊 , Zhang 张 Hang 航 , Zhu 朱 Yiwu 益武 , Luo 罗 Gaofeng 高峰 , Zuo 左 Zhiyue 峙岳 , Ruan 阮 Xinchao 新朝 , Guo 郭 Ying 迎
Published: July 2023

Underwater quantum communication plays a crucial role in ensuring secure data transmission and extensible quantum networks in underwater environments. However, the implementation of such applications encounters challenges due to the light attenuation caused by the complicated natural seawater. This paper focuses on employing a model based on seawater chlorophyll-a concentration to characterize the absorption and scattering of light through quantum channels. We propose a multi-scattering random channel model, which demonstrates characteristics of the excess noise in different propagation directions of communication links. Furthermore, we consider the fidelity of a continuous-variable quantum teleportation through seawater channel. To enhance transmission performance, non-Gaussian operations have been conducted. Numerical simulations show that incorporating non-Gaussian operations enables the protocol to achieve higher fidelity transmission or lower fidelity fading rates over longer transmission distances.
Tribological Properties of PLA 3D Printed at Different Extrusion Temperature
Authors: Zainal M A , Ismail K I , Yap T C
Published: July 2023

Fused deposition modelling (FDM) 3D printing is widely used to manufacture prototype. To manufacture functional products with FDM 3D printing, several existing challenges have to be solved. Tribological behaviour of 3D printed parts has to be improved and optimised. In current study, friction and wear behaviours of 3D printed polylactic acid (PLA) printed at different extrusion temperature (190°C, 200°C, 210°C, 220°C, 230°C) sliding against steel disc were investigated. Pin on disc experiments that complies with ASTM G99-95a (2000) were conducted at a normal load of 15 N, and rotational speed of 150 RPM (0.69 m/s). Results showed that increasing the extrusion temperature resulted in a lower pin wear (specific mass loss) and higher friction coefficients. Pins printed at 190°C showed to have the biggest pin mass loss and lowest friction coefficients, whereas pins printed at 230°C showed to have the lowest pin mass loss and highest friction coefficients. This indicates the higher the extrusion temperature, the more capable it is for the deposited material to flow and homogenise with the neighbouring material which creates a flatter surface with less void between layers. Thus, effectively improving the interlayer bond making the FDM 3D printed part less susceptible to shear stress and delamination.
A Novel Metamaterial-Based Stent with Dual Properties of Auxetic and Self-Expanding
Authors: Zhou Yang , Sun Beibei
Published: July 2023

Vascular stents have been widely used in various cardiovascular diseases associated with atherosclerosis, while the potential risks of in-stent restenosis (ISR) and stent thrombosis (ST) still restrict its further development. Here, by combining the self-expanding (SE) mechanism and auxetic metamaterial, a novel SE stent called MBS was proposed and systematically studied. Through the finite element (FE) method, a stent-artery coupling model was established to study the crimping, expanding, and pulsating behaviors of the proposed MBS. Results show that the MBS well retains various advantages, including a large recoverable strain, a large radial resistance force (RRF), and a smaller radial opening force (ROF). Meanwhile, due to the auxetic effect of the adopted re-entrant honeycomb, the MBS shows a significant negative foreshortening behavior, which can be designed from about -5% to about -50%. Besides, fatigue analysis also shows that all strain-based points are within the design criteria. Geometric parameter of RE cell shows a great effect on the comprehensive performance of the MBS, which needs a further optimal design for ideal radial force, foreshortening effect and fatigue performance. In conclusion, the novel design is expected to improve the mechanical properties of the traditional stent, which should be given more attention in further research.
Analysis of a Mechanical Anchoring System for Landing on Asteroids
Authors: Wang Weimin , Yung K. L.
Published: July 2023

The landing process to an asteroid is discussed with a Nimble Lander. The miniature harpoons are chosen as the anchoring device to landing to asteroid in the Nimble Lander. The analysis results provide detailed information of the anchoring with harpoon as anchoring device. Many different designs of harpoon have been tested by simulation, the best of three designs of harpoon are analyzed for anchoring to Apophis. Instead of the modelling of the anchor as a rigid cylindrical projectile in penetration models, the deformation of the harpoon is fully considered in the anchoring analysis. The analysis provides ground base a reliable design anchoring system for landing to Asteroids.
Finite Element Modeling and Simulation Analysis of Non-Pyrotechnics Separation Device
Authors: Liu Yanhao , Pan Yi , Sun Beibei
Published: July 2023

The research object of this paper is non-pyrotechnics separation device based on SMA. The non-pyrotechnics separation device with different buffer materials is simulated and analyzed by setting accurate simulation parameters. The results show that when the cushion material is TC4, the maximum acceleration of the housing is 269.3g and the separation of the device is completed at 11ms. When the cushion material is rubber, the maximum acceleration of the housing is 122 g, and the device is separated at 12.56 ms.
Theoretical Study on the Nonlinear Dynamic Response of Propulsion Shafting under Time-Varying Hull Motion
Authors: Changyou Huang , Jianzhong Hu
Published: July 2023

Due to the effect of external elements such sea waves and sea wind, the ship will unavoidably produce 6 degrees of freedom of movement, with roll motion being the most likely to occur and having the greatest impact. This paper establishes a general dynamic model of the propulsion shafting based on Timoshenko beam theory, the concentrated mass method, and Lagrange’s equation under roll motion and translation motion to study the dynamic behaviour of the propulsion shafting under roll motion and translation motion. FFT, axis trajectory, Poincaré map, and 3D spectrogram were utilized to examine the impact of motion amplitude, frequency, and rotation speed on the propulsion shafting’s dynamic response. The results demonstrated that base motion significantly affects the dynamics of the propulsion shafting, resulting in many components appearing in the system’s response spectrum, and the system changes from quasi-periodic to chaotic motion when base motion amplitude or frequency rises.
Encapsulating therapeutic cells in RGD-modified agarose microcapsules
Authors: Dutcher Megan , Chewchuk Simon , Benavente-Babace Ainara , Soucy Nicholas , Wan Fan , Merrett Kim , Davis Darryl R , Harden James L , Godin Michel
Published: July 2023

Current cell-based strategies for repairing damaged tissue often show limited efficacy due to low cell retention at the site of injury. Encapsulation of cells within hydrogel microcapsules demonstrably increases cell retention but benefits can be limited due to premature cell escape from the hydrogel microcapsules and subsequent clearance from the targeted tissue. We propose a method of encapsulating cells in agarose microcapsules that have been modified to increase cell retention by providing cell attachment domains within the agarose hydrogel allowing cells to adhere to the microcapsules. We covalently modified agarose with the addition of the cell adhesion peptide, RGD (arginine, glycine, aspartic acid). We then used a microfluidic platform to encapsulate single cells within 50 μm agarose microcapsules. We tracked encapsulated cells for cell viability, egress from microcapsules and attachment to microcapsules at 2 h, 24 h, and 48 h after encapsulation. Many encapsulated cells eventually egress their microcapsule. Those that were encapsulated using RGD-modified agarose adhered to the outer surface of the microcapsule following egress. NIH 3T3 cells showed nearly 45% of egressed cells attached to the outside of RGD modified agarose microcapsules, while minimal cellular adhesion was observed when using unmodified agarose. Similarly, human umbilical vein endothelial cells had up to 33% of egressed cells attached and explant-derived cardiac cells showed up to 20% attachment with the presence of RGD binding domains within the agarose microcapsules.
A numerical study on the impact of lubricant rheology and surface topography on heavily loaded non-conformal contacts
Authors: Prajapati Deepak K , Ahmad Dilshad , Katiyar Jitendra K , Prakash Chander , Ajaj Rafic M
Published: July 2023

The increasing requirement of high-power density (power throughput/ weight) in modern day machines lead to thin film lubrication condition in various machine components (rolling element bearings, gears, cams, etc,) due to severe loading conditions. Surface roughness features and lubricant rheology plays a vital role in thin film lubrication, and significantly affects the lubrication performance and lifetime of machine components. The present work demonstrates surface topography and lubricant rheology effects on the traction coefficient for heavily loaded non-conformal contacts. The load-sharing concept considering elastic-plastic deformation of asperities, and Carreau shear-thinning rheological model is employed to describe the dry rough contacts and non-Newtonian behavior of lubricant. An influence of surface topography parameters such as roughness, skewness, kurtosis, and pattern ratio on the traction coefficient is discussed. From results, it is found that among different surface topographies, negatively skewed surfaces having isotropic surface pattern exhibit minimum traction coefficient. The load share function and the critical rolling speed are determined for various surface topographies which provides further insights into the surface topography effect on traction coefficient. The findings of present study are noteworthy as they provide a theoretical basis for an assessment of the lubrication performance of heavily loaded non-conformal contacts.
Effects of equal channel angular rolling process on the mechanical properties of Al-Cu two-layer sheets: experimental and numerical approaches
Authors: Darvishi Mostafa , Morovvati Mohammadreza , Aghchai Abdolhossein Jalali
Published: July 2023

This study investigates the mechanical properties and microstructural characteristics of explosion-welded Al/Cu two-layer strips during the ECAR process using finite element simulations and experiments. Furthermore, the explosion-welded Al/Cu two-layer strip was examined with various configurations to determine the effects of die angle and friction coefficient on the distributions of effective strain and stress. In addition, the experimental and computational approaches were utilized to explore the ECAR process in two routes, RA and RC, for three directions. Finite element simulations were run and validated using experimental data. The findings show that the ECAR method is effective to enhance the mechanical characteristics of the strips. Moreover, the obtained results represent that the ECAR process reduced the size of the grains. Furthermore, it was shown that by increasing the number of routes in the ECAR process, the stress values were increased. However, the ductility of the two-layer strip was decreased. According to the current study, the route and the number of routes used in the ECAR process have a considerable effect on the strength of the two-layer strip.
Misregulation of cell cycle-dependent methylation of budding yeast CENP-A contributes to chromosomal instability
Authors: Mishra Prashant K. , Au Wei-Chun , Castineira Pedro G. , Ali Nazrin , Stanton John , Boeckmann Lars , Takahashi Yoshimitsu , Costanzo Michael , Boone Charles , Bloom Kerry S. , Thorpe Peter H. , Basrai Munira A.
Published: July 2023

In this study, we show for the first time that Cse4 methylation is regulated by the cell cycle and that the constitutive methylation of Cse4 interferes with the productive association of kinetochore protein complexes at the CEN chromatin, which leads to kinetochore dysfunction and chromosome instability.
Long COVID: what is known and what gaps need to be addressed
Authors: Krishna Benjamin , Wills Mark , Sithole Nyaradzai
Published: July 2023

Introduction

Long COVID is a chronic condition that follows after acute COVID-19 and is characterized by a wide range of persistent, cyclic symptoms.

Sources of data

PubMed search for publications featuring ‘Long COVID’ or ‘post-acute sequelae of COVID-19’.

Areas of agreement

Long COVID occurs frequently post-acute COVID-19, with a majority of people experiencing at least one symptom (such as cough, fatigue, myalgia, anosmia and dyspnoea) 4 weeks after infection.

Areas of controversy

The specific symptoms and the minimum duration of symptoms required to be defined as Long COVID.

Growing points

There is a consistent reduction in Long COVID incidence amongst vaccinated individuals, although the extent of this effect remains unclear.

Areas timely for developing research

There is an urgent need to understand the causes of Long COVID, especially extreme fatigue more than 6 months after infection. We must understand who is at risk and whether reinfections similarly risk Long COVID.
Associations between sleep health and grey matter volume in the UK Biobank cohort (n= 33 356)
Authors: Schiel Julian E , Tamm Sandra , Holub Florian , Petri Roxana , Dashti Hassan S , Domschke Katharina , Feige Bernd , Goodman Matthew O , Jones Samuel E , Lane Jacqueline M , Ratti Pietro-Luca , Ray David W , Redline Susan , Riemann Dieter , Rutter Martin K , Saxena Richa , Sexton Claire E , Tahmasian Masoud , Wang Heming , Weedon Michael N , Weihs Antoine , Kyle Simon D , Spiegelhalder Kai
Published: July 2023

As suggested by previous research, sleep health is assumed to be a key determinant of future morbidity and mortality. In line with this, recent studies have found that poor sleep is associated with impaired cognitive function. However, to date, little is known about brain structural abnormalities underlying this association. Although recent findings link sleep health deficits to specific alterations in grey matter volume, evidence remains inconsistent and reliant on small sample sizes. Addressing this problem, the current preregistered study investigated associations between sleep health and grey matter volume (139 imaging-derived phenotypes) in the UK Biobank cohort (33 356 participants). Drawing on a large sample size and consistent data acquisition, sleep duration, insomnia symptoms, daytime sleepiness, chronotype, sleep medication and sleep apnoea were examined. Our main analyses revealed that long sleep duration was systematically associated with larger grey matter volume of basal ganglia substructures. Insomnia symptoms, sleep medication and sleep apnoea were not associated with any of the 139 imaging-derived phenotypes. Short sleep duration, daytime sleepiness as well as late and early chronotype were associated with solitary imaging-derived phenotypes (no recognizable pattern, small effect sizes). To our knowledge, this is the largest study to test associations between sleep health and grey matter volume. Clinical implications of the association between long sleep duration and larger grey matter volume of basal ganglia are discussed. Insomnia symptoms as operationalized in the UK Biobank do not translate into grey matter volume findings.
Periprosthetic Joint Infection: Current Clinical Challenges
Authors: Nelson Sandra B , Pinkney Jodian A , Chen Antonia F , Tande Aaron J
Published: July 2023

Over the last several decades, periprosthetic joint infection has been increasing in incidence and is occurring in more complex patients. While there have been advances in both surgical and medical treatment strategies, there remain important gaps in our understanding. Here, we share our current approaches to the diagnosis and management of periprosthetic joint infection, focusing on frequent clinical challenges and collaborative interdisciplinary care.
Pericoronary Adipose Tissue Density, Inflammation, and Subclinical Coronary Artery Disease Among People With HIV in the REPRIEVE Cohort
Authors: Foldyna Borek , Mayrhofer Thomas , Zanni Markella V , Lyass Asya , Barve Radhika , Karady Julia , McCallum Sara , Burdo Tricia H , Fitch Kathleen V , Paradis Kayla , Fulda Evelynne S , Diggs Marissa R , Bloomfield Gerald S , Malvestutto Carlos D , Fichtenbaum Carl J , Aberg Judith A , Currier Judith S , Ribaudo Heather J , Hoffmann Udo , Lu Michael T , Douglas Pamela S , Grinspoon Steven K
Published: July 2023

Background

Pericoronary adipose tissue (PCAT) may influence plaque development through inflammatory mechanisms. We assessed PCAT density, as a measure of pericoronary inflammation, in relationship to coronary plaque among people with human immunodeficiency virus (HIV [PWH]) and to a matched control population.

Methods

In this baseline analysis of 727 participants of the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) Mechanistic Substudy, we related computed tomography–derived PCAT density to presence and extent (Leaman score) of coronary artery disease (CAD), noncalcified plaque, coronary artery calcium (CAC), and vulnerable plaque features using multivariable logistic regression analyses. We further compared the PCAT density between PWH and age, sex, body mass index, CAC score, and statin use–matched controls from the community-based Framingham Heart Study (N = 464), adjusting for relevant clinical covariates.

Results

Among 727 REPRIEVE participants (age 50.8 ± 5.8 years; 83.6% [608/727] male), PCAT density was higher in those with (vs without) coronary plaque, noncalcified plaque, CAC >0, vulnerable plaque, and high CAD burden (Leaman score >5) (P < .001 for each comparison). PCAT density related to prevalent coronary plaque (adjusted odds ratio [per 10 HU]: 1.44; 95% confidence interval, 1.22–1.70; P < .001), adjusted for clinical cardiovascular risk factors, body mass index, and systemic immune/inflammatory biomarkers. Similarly, PCAT density related to CAC >0, noncalcified plaque, vulnerable plaque, and Leaman score >5 (all P ≤ .002). PCAT density was greater among REPRIEVE participants versus Framingham Heart Study (−88.2 ± 0.5 HU versus −90.6 ± 0.4 HU; P < .001).

Conclusions

Among PWH in REPRIEVE, a large primary cardiovascular disease prevention cohort, increased PCAT density independently associated with prevalence and severity of coronary plaque, linking increased coronary inflammation to CAD in PWH.
Safe and predictable transcatheter removal of broken coronary guidewires: the ‘knuckle-twister’ technique: a case series report
Authors: Leibundgut Gregor , Achim Alexandru , Krivoshei Lian
Published: July 2023

Background

Guidewire fracture and loss is a rare but well-known and feared complication of percutaneous coronary interventions. With the increasing number of complex coronary interventions and procedures for chronic total occlusions, operators face new challenges and boundaries, and the need for solutions to otherwise rare complications is increasing.

Case summary

We have developed a simple and practical method for retrieving fractured and lost guidewires, called the ‘knuckle-twister’ technique. This article summarizes seven cases in which guidewires lost in the coronary vasculature have been successfully removed and describes this technique in detail. The goal was to gather different clinical scenarios: free wire lost in situ, wire jailed behind stent struts, wire in small branches, part of the wire protruding into the aorta, ‘invisible’ guidewire microfilaments/coils, etc.

Discussion

The innovation of the knuckle-twister consists in folding a polymer-jacketed guidewire and transforming it into an open lasso that tightens when twisted. In vitro, its grip strength and pulling force was tested and exceeded 1.5 kg. Moreover, in all in vivo cases, the lost material could be efficiently and quite rapidly retrieved with this simple and highly reproducible technique.

Key clinical message

Broken guidewires that were lost in the coronary vasculature can be safely retrieved with this novel and simple technique requiring no special safety equipment.
Venality in town: the civic participation of venal forestry officers in Villemur (1671–1776)
Authors: Salje Elisabeth
Published: July 2023

Ancien régime venality of office has been axiomatically associated with inefficiency and corruption. In the case of mid-ranking provincial royal forestry officers, such behaviour was blamed on the limited promotion opportunities and poor financial rewards of their office. This article argues that active engagement with municipal politics was an additional, and more effective, compensation strategy for these office-holders because they could capitalize on the opportunities provided by the introduction of municipal venality in 1692. While financially unrewarding, civic participation enhanced their local status and prestige. It also contributed to the concentration of municipal power into few privileged hands, which over time severely undermined more participative forms of local governance. Ultimately, the failure of Colbert’s vision of forestry as an efficient public service was not due to the venal nature of the forestry office per se, but to office-holders sacrificing dedication to the king’s service for enhanced municipal prominence.
The thicker the endometrium, the better the neonatal outcomes?
Authors: Wu Jing , Huang Jianlei , Dong Jie , Xiao Xifeng , Li Mao , Wang Xiaohong
Published: July 2023

STUDY QUESTION

Is endometrial thickness (EMT) on the hCG trigger day related to the neonatal outcome of a single birth after fresh embryo transfer (ET)?

SUMMARY ANSWER

An EMT ≤7.8 mm was an independent predictor for greater odds of preterm delivery (PTD) of singletons born after fresh ET.

WHAT IS KNOWN ALREADY

There may be a positive association between live birth rates and EMT after fresh ET. It is still unknown whether a similar association is seen for the neonatal outcomes of singletons in fresh cycles.

STUDY DESIGN, SIZE, DURATION

This retrospective study involved singleton live births in women undergoing autologous IVF cycles during the period from 1 October 2016 to 31 July 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2010 women who fulfilled the inclusion criteria were included. A multivariable regression analysis was performed to detect the relationship between EMT and neonatal outcomes after controlling for potential confounders. Smooth curve fitting and threshold effect analysis were used to evaluate the accurate cutoff value of EMT.

MAIN RESULTS AND THE ROLE OF CHANCE

The results of the multivariate regression analyses showed that the odds of PTD were reduced by 45% with an EMT of 9.00–9.90 mm (adjusted odds ratio (OR): 0.55, 95% CI: 0.13 to 0.98; P = 0.0451), reduced by 58% with an EMT of 10.00–10.90 mm (adjusted OR: 0.42, 95% CI: 0.06 to 0.87; P = 0.0211) and reduced by 75% with an EMT >11 mm (adjusted OR: 0.25, 95% CI: 0.04 to 0.66; P = 0.0034), compared to the group with an EMT of 6.00–8.90 mm. It could also be seen from the adjusted smooth curves that the odds of PTD decreased and gestational age (GA) increased with increasing EMT. Combined with the analysis of threshold effects, the results indicated that when the EMT was ≤7.6 mm, the incidence of PTD decreased as the EMT gradually increased (adjusted OR: 0.47, 95% CI: 0.03 to 0.99; P = 0.0107), and when the EMT was ≤7.8 mm, the GA increased (adjusted β: 1.94, 95% CI: 1.26 to 2.63; P < 0.0001) as the EMT gradually increased.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of our study is its retrospective design. Although we found a significant decrease in PTD as the EMT increased, in terms of GA, the magnitude of the differences was modest, which may limit the clinical relevance of the findings.

WIDER IMPLICATIONS OF THE FINDINGS

Our data provide new insight into the relationship between EMT and neonatal outcomes by indicating that a thin endometrium of ≤7.8 mm is associated with an increased odds of PTD of singletons after fresh ET.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (grant no. 82071717). There are no conflicts of interest.
Adiposity and risk of oesophageal cancer subtypes in the Million Women Study
Authors: Sweetland Siân , Floud Sarah , Gaitskell Kezia , Reeves Gillian K ,   the Million Women Study Collaborators, Banks Emily , Beral Valerie , Carpenter Lucy , Dezateux (chair) Carol , Floud Sarah , Green Jane , Patnick Julietta , Peto Richard , Reeves Gillian , Sudlow Cathie , Abbott Simon , Alison Rupert , Atkinson Sarah , Baker Krys , Balkwill Angela , Barnes Isobel , Black Judith , Blanks Roger , Brown Anna , Chadwick Andrew , Ewart Dave , Floud Sarah , Gaitskell Kezia , Gathani Toral , Gerrard Laura , Goodill Adrian , Hermon Carol , Hogg Darren , Hudak Alison , Lingard Isobel , Kan Sau Wan , Langston Nicky , Pepier Keren , Pirie Kirstin , Reeves Gillian , Shaw Keith , Sherman Emma , Smith-Byrne Karl , Strange Helena , Sweetland Siân , Travis Ruth , Trickett Lyndsey , Wotton Clare , Yang Owen , Young Heather
Published: July 2023

Background

The strong association of body mass index (BMI) with increased oesophageal adenocarcinoma risk is established, but its relationship with oesophageal squamous cell carcinoma is less clear. There is little evidence regarding the association of abdominal adiposity with either subtype.

Methods

In a large prospective cohort of women in the UK, mean age 56.2 [standard deviation (SD) = 4.9] years, we investigated the risk of oesophageal adenocarcinoma and squamous cell carcinoma in relation to self-reported BMI, waist circumference (WC) and waist-hip ratio (WHR), using Cox regression to estimate adjusted relative risks (RR) and 95% confidence intervals (CIs), taking account of potential reverse causation bias.

Results

During mean follow-up of 17.7 (SD = 4.9) years, 1386 adenocarcinomas and 1799 squamous cell carcinomas of the oesophagus were registered among 1 255 529 women. Compared with women of BMI 22.5 to <25 kg/m2, those with BMI ≥35 kg/m2 had a 2.5-fold risk of adenocarcinoma (adjusted RR = 2.46, 95% CI = 1.99–3.05) and an almost 70% reduction in risk of squamous cell carcinoma (RR = 0.32, 95% CI = 0.22–0.46). These associations were broadly similar in each 5-year follow-up period, and were evident in both never and ever smokers, although somewhat stronger for squamous cell carcinoma among current and past smokers than in never smokers (Pheterogeneity = 0.007). After controlling for BMI, WC and WHR were associated with risk of squamous cell carcinoma but not adenocarcinoma.

Conclusions

In this population of middle-aged women, there was robust evidence that greater BMI is associated with an increased risk of oesophageal adenocarcinoma and a reduced risk of squamous cell carcinoma.