bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Platform with Rotating Airflow Excitation and Stationary Blisk Vibration Measurement
Authors: Ouyang Luohui , Bi Qingzhen , Shang Hai , Zhu Limin , Yu Jianhua
Published: April 2021

With the question that the vibration of the realistic blisk in the engine is hard to be predicted, researchers need an experimental test platform to study the realistic dynamic properties and monitor the vibration of the designed blisk. For keeping the relative motion between airflow and blisk in a real engine, and facilitating the measurement of the blisk vibration, a new experimental platform with rotating air excitation and stationary blisk vibration measurement is developed in this paper. Firstly, the schematic diagram of the test platform is shown and all the components are illustrated clearly, including the stationary airflow excitation system, the test rig, and the vibration measurement system. Then two typical experiments are conducted with the designed academic blisk. A stationary excitation and a transient acceleration excitation are employed to the stationary blisk. Through the time-frequency analysis of the vibration signal measured by the Laser Doppler Vibrometer, the source of each component of the vibration signal is obtained. The experiment results show that the stationary and transient vibration of the blisk can be measured and identified correctly.
A comparative study on the numerical solution algorithms of gas Reynolds equation
Authors: Wang Yongliang , Wang Yi , Zheng Longkai
Published: April 2021

The improved P* algorithm is studied for solving the Reynolds equation by finite difference method. P* algorithm has the advantages of distinct mathematical concepts and simple programming. Firstly, The P* algorithm is combined with the Successive Over-Relaxation (SOR) method, considering the influence of the selection of relaxation factor on the calculation results. The optimal relaxation factor is determined to be 0.97, in this case, the minimum film thickness of flexible gas foil bearing can be calculated to 3.8 μm. Then, by changing the position of P*, the algorithm accuracy, sensitivity to the initial value, and computational efficiency of different P* algorithms are compared and studied. In the end, the P* algorithm is compared with the Newton-Raphson algorithm, it is found that although the Newton-Simpson algorithm computations the matrix dimension is large; but it has the advantages of fast computing speed and high efficiency.
Numerical Study on Particle Deposition Characteristics of Impingement Effusion Cooling Structure
Authors: Li Bingran , Liu Cunliang , Li Lin , Chen Wenbin , He Yihong
Published: April 2021

The paper investigates the effect of impingement velocity and particle diameters on the flow and solid-phase deposition characteristics of the impingement effusion cooling structure by numerical simulation of gas-solid two-phase flow using DPM with UDF. The results show that under the same condition of the particle diameter, both the particle deposition flux and the particle deposition rate become increase with the increasing of the impingement velocity while the dimensionless particle deposition rate increases first and then decreases; Under the same condition of the impingement velocity, with the increase of the particle diameter, the particle deposition flux increases, while the particle deposition rate and the dimensionless deposition rate of the particle both increase first and then decrease. Taken together, Brownian motion of particles, turbulent diffusion, and particle inertia and flow characteristics is the main factors that affect the solid-phase particle deposition behaviour.
Volumetric entropy generation rate associated with tip clearance flow in linear cascade
Authors: Bingxiang Long , Qin Chen , Zebin Ren , Daxiong Liao
Published: April 2021

The tip clearance flow structure and its corresponding entropy generation rate of a linear cascade with 1.85mm radial tip clearance operating under three different incidence angle are investigated. The incidence angle influences the tip leakage vortex position as well as the size of the tip leakage vortex. Larger incidence angle results in larger tip leakage vortex and pushes the tip leakage vortex further away from the suction side. The entropy generation rate related to the tip clearance flow structure is calculated and it is confirmed that tip clearance flow is the main major source of aerodynamic loss in linear cascade. Larger incidence angle leading to higher entropy generation rate. Results also show that it’s not the core region of tip leakage vortex but the edge vortex and shear layer of the tip clearance flow which has the highest entropy generation rate. When operating under an incidence angle of 4°, there exist an extra high entropy generation rate region in main flow. It is found that the compression and expansion of fluid due to the existence of tip clearance vortex was the main reason for this extra high entropy generation.
Investigation of noise characteristics of periodic jet impinging on a flat plate
Authors: Liu Xin , Hou Jiaxin , Huang Heyuan , Guo Xiaoliang , Xie Junlong
Published: April 2021

Noise characteristics of periodic jet impinging on a flat plate are investigated. The numerical model is established by large eddy simulation and FW-H acoustic analogy method. Compared with experimental data obtained by noise measurement experiment, the effects of acoustic integral surface and different subgrid-scale models on noise simulation results are studied. The accuracy of the optimized numerical model is also validated by verification experiment. Further, the present numerical model is applied to numerical prediction of noise directivity and spectrum distribution with different waveforms and periodic frequency. Compared with the steady impinging jet, noise characteristic of periodic jet impinging on a flat plate are presented and the mechanism of acoustic source is analyzed. The present work provides a reference value for the analysis and control of noise of periodic jet impinging on a flat plate.
Research on structure characteristics of the helium-lubricated spiral grooved thrust bearing for helium turbine expander
Authors: Zhang X H , Peng N , Dong B , Li KR , Liu L Q
Published: April 2021

The helium-lubricated spiral grooved thrust bearing of helium turbo expander was studied by numerically simulating the steady-state non-linear Reynolds equation, the Reynolds equation of the pressure was solved by finite difference method (FDM), the film pressure distribution is calculated iteratively by MATLAB program, the structural parameters including the spiral angle, the groove length ratio, the groove width ratio influenced on the static characteristics were analyzed. The results show that: The bearing loading capacity of helium lubricated spiral grooved thrust gas bearing is lower than that of air lubricated bearing under the same conditions; The viscosity of the lubricant only affects the gas carrying capacity of the thrust disc when the spiral groove is on the bearing, while the density of the lubricant has a greater influence on the bearing loading capacity; When the spiral groove is designed on the rotor thrust disc, the bearing loading capacity of the spiral grooved thrust bearing increases by 6% on average compared with that of the spiral groove on the bearing.
The influence of wall roughness on centrifugal pump performance
Authors: Wang Von-Hao , Li Kun-Hang , Li Jing-Yin
Published: April 2021

Wall roughness is an important factor in the pump head and efficiency. Influence of wall roughness on the performance of a centrifugal pump is conducted with numerical approach. In the present study, a critical value of wall roughness is found. The performance of the pump decreases significantly while the wall roughness is less than critical value and decreases slightly while exceeding it. Influence of wall roughness of each domain is compared; the result revealed that the influence of wall roughness was decreased for volute, impeller, inlet and outlet respectively. Blade wall roughness of impeller has the greatest effect on pump performance, and pressure surface roughness has a greater influence than that for suction surface. This study could provide a reference for the manufacture and design of this type of centrifugal pump.
Effect of taper parameters on mechanical seal performance of taper/pores composite mechanical seal
Authors: Cheng X P , Liu Q , Zhang Y L , Wei J
Published: April 2021

a new combination fluid seal with the cone/pores is given, and the 3D fluid/solid coupling theory model is constructed, considering the interaction between the liquid pressure field and the stress deformation of the seal rings, led to seal clearance unceasingly change. Through the corresponding numerical calculation, film pressure distribution and end face deformation situation are obtained between the seal end faces, the influence rule of taper on sealing performance under the high and low pressure conditions is analyzed. The results show that the dynamic pressure effect caused by rhomboid pores can produce circumferential and radial wavy deformation of the seal end faces, while the static pressure effect also changes with the taper change of the end faces. For the low pressure and medium speed equipment, the conical end face which the taper is 0-2.4 should be chosen priority. For higher pressure and rotational speed device, the convergence end face seal which the taper is 0-2.4 should first be chosen.
Modelling of polymer optical fiber-based solar concentrators
Authors: Arrue J , Vieira A , García-Ramiro B , Illarramendi M A , Jiménez F , Zubia J
Published: April 2021

A comprehensive model for the theoretical simulation of luminescent solar concentrators (LSCs) has been developed and examined. It can simulate the interdependent effects of multiple dopants having two main electronic energy states, which are incorporated simultaneously into the fiber core, as well as the effect of the cladding. The available experimental results appear to confirm the accuracy of the model, which is a valuable tool for gaining insight into the behavior of LSC prototypes, since it may guide the designers at the early stages of optimization processes.
Research on static recrystallization behaviour of pure molybdenum rods during forging
Authors: Zhang Qifei , Wang Aiqin , Chen Yao , Xie Jingpei , Ma Douqin , Ha Sihu
Published: April 2021

In this work, thermal compression experiment of pure molybdenum rods with sintered density of 9.7–9.8 g cm−3 were performed on the Gleeble-1500D thermal simulator. The double-pass vacuum high-temperature compression test was carried out in a deformation temperature of 1200 °C–1350 °C, a strain rate of 3 s−1 and an interval time of 10–500 s. The stress-strain curve was obtained and analysed. The static softening rate was calculated by the 2% compensation method of yield stress, and the curve of that was fitted. The results show that the softening rate is proportional to the interval time and the deformation temperature. The static recrystallization activation energy and critical temperature of pure molybdenum rod is 583.79 kJ mol−1 and 1365 °C, respectively. Besides, the static recrystallization kinetics model and grain growth model of pure molybdenum rod was established and microstructure evolution of molybdenum was analysed during the deformation process.
Repeatability of Quantitative 18F-FET PET in Glioblastoma
Authors: Ferjančič Peter , Ebert Martin A , Francis Roslyn , Nowak Anna K , Jeraj Robert
Published: April 2021

Purpose: O-(2-[18F]fluoroethyl)-L-tyrosine (FET), a PET radiotracer of amino acid uptake, has shown potential for diagnosis and treatment planning in patients with glioblastoma (GBM). To improve quantitative assessment of FET PET imaging, we evaluated the repeatability of uptake of this tracer in patients with GBM. Methods: Test-retest FET PET imaging was performed on 8 patients with histologically confirmed GBM, who previously underwent surgical resection of the tumour. Data were acquired according to the protocol of a prospective clinical trial validating FET PET as a clinical tool in GBM. SUVmean, SUVmax and SUV98% metrics were extracted for both test and retest images and used to calculate 95% Bland-Altman limits of agreement (LoA) on lesion-level, as well as on volumes of varying sizes. Impact of healthy brain normalization on repeatability of lesion SUV metrics was evaluated. Results: Tumour LoA were [0.72, 1.46] for SUVmean and SUVtotal, [0.79,1.23] for SUVmax, and [0.80,1.18] for SUV98%. Healthy brain LoA were [0.80,1.25] for SUVmean, [0.80,1.25] for SUVmax, and [0.81,1.23] for SUV98%. Voxel-level SUV LoA were [0.76, 1.32] for tumour volumes and [0.80, 1.25] for healthy brain. When sampled over maximum volume, SUV LoA were [0.90,1.12] for tumour and [0.92,1.08] for healthy brain. Normalization of uptake using healthy brain volumes was found to improve repeatability, but not after normalization volume size of about 15 cm3. Conclusions Advances in Knowledge and Implications for Patient Care: Repeatability of FET PET is comparable to existing tracers such as FDG and FLT. Healthy brain uptake is slightly more repeatable than uptake of tumour volumes. Repeatability was found to increase with sampled volume. SUV normalization between scans using healthy brain uptake should be performed using volumes at least 15 cm3 in size to ensure best imaging repeatability.
Self-shielding copper substrate neutron supermirror guides
Authors: Bentley P M , Hall-Wilton R , Cooper-Jensen C P , Cherkashyna N , Kanaki K , Schanzer C , Schneider M , Böni P
Published: April 2021

The invention of self-shielding copper substrate neutron guides is described, along with the rationale behind the development, and the realisation of commercial supply. The relative advantages with respect to existing technologies are quantified. These include ease of manufacture, long lifetime, increased thermal conductivity, and enhanced fast neutron attenuation in the keV-MeV energy range. Whilst the activation of copper is initially higher than for other material options, for the full energy spectrum, many of the isotopes are short-lived, so that for realistic maintenance access times the radiation dose to workers is expected to be lower than steel and in the lowest zoning category for radiation safety outside the spallation target monolith. There is no impact on neutron reflectivity performance relative to established alternatives, and the manufacturing cost is similar to other polished metal substrates.
Atmospheric trace gas trends obtained from FTIR column measurements in Toronto, Canada from 2002-2019
Authors: Yamanouchi Shoma , Strong Kimberly , Colebatch Orfeo , Conway Stephanie , Jones Dylan B A , Lutsch Erik , Roche Sébastien
Published: April 2021

Total columns of C2H2, C2H6, CH4, CH3OH, CO, H2CO, HCl, HCN, HCOOH, HF, HNO3, N2O, NH3 and O3 were retrieved from 2002-2019 using a Fourier transform infrared (FTIR) spectrometer at the University of Toronto Atmospheric Observatory (TAO). Trends and enhancement events were determined by fitting trended Fourier series, and bootstrapping was used to identify the statistical significance. Trends from 2002 to 2019 (%/year, with 2σuncertainties) were found for C2H2 (−1.12 ± 0.30), C2H6 (−0.74 ± 0.73 from 2002–2008 and 1.19 ± 0.27 from 2009–2019), CH4 (0.26 ± 0.10 from 2002–2008 and 0.41 ± 0.03 from 2009–2019), CO (−0.90 ± 0.07), HCN (−0.51 ± 0.21), HCOOH (−2.15 ± 0.64), HF (0.59 ± 0.11), HNO3 (0.36 ± 0.13), N2O (0.28 ± 0.02), NH3 (3.56 ± 0.85), and O3 (0.28 ± 0.19 and −0.05 ± 0.07 for tropospheric and stratospheric columns, respectively). The GEOS-Chem chemical transport model showed that wetland emissions were the largest contributor to CH4 columns measured at TAO (average relative contribution of 31.7%), and that CH4 oxidation was a major source of CO (accounting for 30.9%).
The effect of annealing temperature on Cu2ZnGeSe4 thin films and solar cells grown on transparent substrates
Authors: Ruiz-Perona Andrea , Sánchez Yudania , Guc Maxim , Kodalle Tim , Placidi Marcel , Merino José Manuel , Cabello Fátima , García-Pardo Marina , León Máximo , Caballero Raquel
Published: April 2021

Semi-transparent solar cells are the next step for photovoltaics into our daily life. Over the last years, kesterite-type material has attracted a special attention to be used as an absorber in thin-film solar cells because of its low toxicity and earth abundant constituents. Here, Cu2ZnGeSe4 (CZGSe) thin films are grown by co-evaporation and subsequent annealing at a maximum temperature of 480 °C or 525 °C onto Mo/V2O5/FTO/glass stacks. The goal of this work is to investigate the influence of the annealing temperature on the composition, morphology, vibrational properties, and transmittance of CZGSe layers, the formation of secondary phases, and distribution of elements within the absorber layer as well as on the optoelectronic properties of the corresponding solar cell devices. Raising the annealing temperature to 525 °C leads to a more uniform distribution of Cu, Zn, Ge and Se throughout the absorber layer, a reduction of the presence of the GeSe2 secondary phase, which is mainly detected at 480 °C, a larger grain size and the formation of a thicker MoSe2 layer at the CZGSe/back contact interface. The strategy of increasing the annealing temperature allows for improved J–V characteristics and higher spectral response resulting in an enhanced device performance of 5.3% compared to 4.2% when using 525 °C and 480 °C, respectively. Both absorber layers present an optical band gap energy of 1.47 eV. Furthermore, higher annealing temperature has beneficial effect to the CZGSe-based devices without losses in total transmitted light because of the higher diffuse transmittance. This work shows first promising semi-transparent CZGSe-based solar cells possibly open up new routes of applications.
Of actors, cities and energy systems: advancing the transformative potential of urban electrification
Authors: Romero-Lankao Patricia , Wilson Alana , Sperling Joshua , Miller Clark , Zimny-Schmitt Daniel , Sovacool Benjamin , Gearhart Chris , Muratori Matteo , Bazilian Morgan , Zünd Daniel , Young Stan , Brown Marilyn , Arent Doug
Published: April 2021

The electrification of transportation and the integration of electric vehicles (EVs) with buildings connected to clean grids has been touted as one of the key solutions to the global decarbonization challenge. Cities are on the frontlines of current and future electrification, as they depend on and drive electricity generation, distribution, and use. City actors also occupy a central role in the actions to enable electrification to support energy transitions in efficient, equitable, environmentally sound, and resilient ways. Currently, however, research and development on the interactions between actors, cities and energy systems is predominantly conducted in disciplinary siloes. This topical review analyzes the transformational potential of urban electrification. It focuses on efforts to electrify transportation and integrate EVs with buildings connected to a clean grid. We find that actions in these area are driving change; they are adopted by wealthier populations and on an experimental basis by specific communities. Their larger-scale growth is constrained by institutional, behavioral, and infrastructural factors. We also find that existing siloed disciplinary approaches are often incompatible with advancing holistic research. To achieve that, divergent communities of scholars need to come together to integrate their research and create broader perspectives. Through incorporation of the social sciences, these perspectives need to consider the societal limits and potentials brought to bear by human behavior and decision making. Only then can urban electrification be understood as the empirically rich and socially complex topic that it is. And only with this understanding will innovations and smart policy actions be able to tap into the transformational potential of urban electrification.
A devil’s advocate view on ‘self-organized’ brain criticality
Authors: Gros Claudius
Published: April 2021

Stationarity of the constituents of the body and of its functionalities is a basic requirement for life, being equivalent to survival in first place. Assuming that the resting state activity of the brain serves essential functionalities, stationarity entails that the dynamics of the brain needs to be regulated on a time-averaged basis. The combination of recurrent and driving external inputs must therefore lead to a non-trivial stationary neural activity, a condition which is fulfiled for afferent signals of varying strengths only close to criticality. In this view, the benefits of working in the vicinity of a second-order phase transition, such as signal enhancements, are not the underlying evolutionary drivers, but side effects of the requirement to keep the brain functional in first place. It is hence more appropriate to use the term ‘self-regulated’ in this context, instead of ‘self-organized’.
Distinct Illness Representation Profiles Are Associated With Anxiety in Women Testing Positive for Human Papillomavirus
Authors: McBride Emily , Marlow Laura A V , Chilcot Joseph , Moss-Morris Rona , Waller Jo
Published: April 2021

Background

Testing positive for human papillomavirus (HPV) at cervical cancer screening has been associated with heightened anxiety. To date, the cognitive determinants of heightened anxiety remain unclear, making it difficult to design effective interventions.

Purpose

This study investigated latent illness representation profiles in women testing positive for HPV with no abnormal cells (normal cytology) and explored associations between these profiles and anxiety.

Methods

Women aged 24–66 (n = 646) who had tested HPV-positive with normal cytology at routine HPV primary screening in England completed a cross-sectional survey shortly after receiving their result.

Results

Latent profile analysis identified three distinct profiles of illness representations (termed “adaptive,” “negative,” and “negative somatic”), which differed significantly in their patterns of illness perceptions. Hierarchal linear regression revealed that these latent illness representation profiles accounted for 21.8% of the variance in anxiety, after adjusting for demographic and clinical characteristics. When compared with adaptive representations (Profile 1), women with negative representations (Profile 2) and negative somatic representations (Profile 3) had significantly higher anxiety, with clinically meaningful between-group differences (mean difference [MD] = 17.26, confidence interval [CI]: 14.29–20.22 and MD = 13.20, CI: 9.45–16.96 on the S-STAI-6, respectively).

Conclusion

The latent illness representation profiles identified in this study provide support for the role of negative beliefs contributing to anxiety in women testing HPV-positive with normal cytology. Characteristics specific to subgroups of highly anxious women (Profiles 2 and 3) could be used by policymakers to target information in routine patient communications (e.g., test result letters) to reduce unnecessary burden. Future research should adopt longitudinal designs to understand the trajectory of illness representations from HPV diagnosis through to clearance versus persistence.
Introduction
Authors: Wert Michael
Published: April 2021

This introduction lays out the narrative structure of the book, discuses the presence of samurai in popular culture, and covers some of the basic myths about the samurai.
War and culture
Authors: Wert Michael
Published: April 2021

Warrior combat and culture are the highlights of this chapter. It details early warrior weapons, armour, and castles, describes how combat changed over time from smaller skirmishes to large-scale battles, and ends with a discussion of the “three conquerors” who brought an end to the Warring States Period. The chapter goes beyond the violence of warrior life. The second half of the chapter illustrates the increased salience of noble culture in daily elite warrior life during a time when a new shogunate, the Muromachi Shogunate, replaced the Kamakura shogunate. Led by the Ashikaga shoguns, this new regime was located in Kyoto, the font of noble culture. Thus, alongside violence, this chapter describes growing warrior “values” and their participation in traditional Japanese arts such as the tea ceremony.
Inventing the samurai
Authors: Wert Michael
Published: April 2021

This chapter argues that the samurai were “invented” in the Tokugawa period as a strictly defined group with a unique identity created through popular culture and codified social cultural practices. Commoners and samurai alike consumed, and participated in, warrior-related activities. People read warrior histories, military science manuals, were influenced by warrior theatre, like the 47 ronin story, and the value therein. It also describes how low-ranking warriors became more political, their education increasing connected to notions of warrior legitimacy and the relationship between warriors and the imperial institution. In so doing, the chapter, chronologically, leads readers to the collapse of the last warrior regime during the Meiji Restoration and the Boshin War.
Philosophy of Physics: A Very Short Introduction
Authors: Wallace David
Published: April 2021

Philosophy of Physics: A Very Short Introduction explores the core topics of philosophy of physics through three key themes: the nature of space and time; the origin of irreversibility and probability in the physics of large systems; how we can make sense of quantum mechanics. Central issues discussed include: the scientific method as it applies in modern physics; the distinction between absolute and relative motion; the way that distinction changes between Newton’s physics and special relativity; what spacetime is and how it relates to the laws of physics; how fundamental physics can make no distinction between past and future and yet a clear distinction exists in the world we see around us; why it is so difficult to understand quantum mechanics, and why doing so might push us to change our fundamental physics, to rethink the nature of science, or even to accept the existence of parallel universes.
Development and Validation of a Liquid Chromatography Mass Spectrometry Method for Simultaneous Measurement of 25(OH)D3, epi-25(OH)D3, 25(OH)D2, Vitamin A, α-Tocopherol, and γ-Tocopherol
Authors: Xiao Yi , Leung Edward Ki Yun
Published: April 2021

Objectives

Fat-soluble vitamins are measured to identify deficiencies that may lead to rickets, osteomalacia, night blindness, and reversible motor and sensory neuropathies. We present a rapid liquid chromatography–mass spectrometry (LC-MS/MS) method that simultaneously measures 25-hydroxyvitamin D3 (25[OH]D3), epi-25(OH)D3, 25(OH)D2, vitamin A, α-tocopherol, and γ-tocopherol.

Methods

We mixed 100 µL serum with internal standard and extracted it by using supported liquid extraction plates. Reconstituted specimens were analyzed by LC-MS/MS with a 10-minute gradient.

Results

The method was linear, covering physiological levels with r2 > 0.99, and the total precision was less than 15% at all quality control levels. The lower limit of the measuring intervals for 25(OH)D3, epi-25(OH)D3, 25(OH)D2, vitamin A, α-tocopherol, and γ-tocopherol were 4 ng/mL, 4 ng/mL, 4 ng/mL, 1 µg/dL, 0.2 µg/mL, and 0.2 µg/mL, respectively, with coefficient of variation of 20% or less. Recoveries were between 92% and 111% for National Institute of Standards and Technology reference materials and 81% and 122% for spike-recovery studies. Comparison studies for vitamin D total, vitamin A, and α-tocopherol demonstrated slopes between 1.04 and 1.11 and r2 between 0.94 and 0.96. Minimal matrix effect was observed for all analytes.

Conclusions

We developed and validated a rapid LC-MS/MS method for the simultaneous measurement of 25(OH)D3, epi-25(OH)D3, 25(OH)D2, vitamin A, α-tocopherol, and γ-tocopherol.
COMETS Analytics: An Online Tool for Analyzing and Meta-Analyzing Metabolomics Data in Large Research Consortia
Authors: Temprosa Marinella , Moore Steven C , Zanetti Krista A , Appel Nathan , Ruggieri David , Mazzilli Kaitlyn M , Chen Kai-ling , Kelly Rachel S , Lasky-Su Jessica A , Loftfield Erikka , McClain Kathleen , Park Brian , Trijsburg Laura , Zeleznik Oana A , Mathé Ewy A
Published: April 2021

Consortium-based research is crucial for producing reliable, high-quality findings, but existing tools for consortium studies have important drawbacks with respect to data protection, ease of deployment, and analytical rigor. To address these concerns, we developed COnsortium of METabolomics Studies (COMETS) Analytics to support and streamline consortium-based analyses of metabolomics and other -omics data. The application requires no specialized expertise and can be run locally to guarantee data protection or through a Web-based server for convenience and speed. Unlike other Web-based tools, COMETS Analytics enables standardized analyses to be run across all cohorts, using an algorithmic, reproducible approach to diagnose, document, and fix model issues. This eliminates the time-consuming and potentially error-prone step of manually customizing models by cohort, helping to accelerate consortium-based projects and enhancing analytical reproducibility. We demonstrated that the application scales well by performing 2 data analyses in 45 cohort studies that together comprised measurements of 4,647 metabolites in up to 134,742 participants. COMETS Analytics performed well in this test, as judged by the minimal errors that analysts had in preparing data inputs and the successful execution of all models attempted. As metabolomics gathers momentum among biomedical and epidemiologic researchers, COMETS Analytics may be a useful tool for facilitating large-scale consortium-based research.
tSFM 1.0: tRNA Structure–Function Mapper
Authors: Lawrence Travis J , Hadi-Nezhad Fatemeh , Grosse Ivo , Ardell David H
Published: April 2021

Motivation

Structure-conditioned information statistics have proven useful to predict and visualize tRNA Class-Informative Features (CIFs) and their evolutionary divergences. Although permutation P-values can quantify the significance of CIF divergences between two taxa, their naive Monte Carlo approximation is slow and inaccurate. The Peaks-over-Threshold approach of Knijnenburg et al. (2009) promises improvements to both speed and accuracy of permutation P-values, but has no publicly available API.

Results

We present tRNA Structure–Function Mapper (tSFM) v1.0, an open-source, multi-threaded application that efficiently computes, visualizes and assesses significance of single- and paired-site CIFs and their evolutionary divergences for any RNA, protein, gene or genomic element sequence family. Multiple estimators of permutation P-values for CIF evolutionary divergences are provided along with confidence intervals. tSFM is implemented in Python 3 with compiled C extensions and is freely available through GitHub (https://github.com/tlawrence3/tSFM) and PyPI.

Availability and implementation

The data underlying this article are available on GitHub at https://github.com/tlawrence3/tSFM.

Supplementary information

Supplementary data are available at Bioinformatics online.
Mindfulness-based interventions: an overall review
Authors: Zhang Dexing , Lee Eric K P , Mak Eva C W , Ho C Y , Wong Samuel Y S
Published: April 2021

Introduction

This is an overall review on mindfulness-based interventions (MBIs).

Sources of data

We identified studies in PubMed, EMBASE, CINAHL, PsycINFO, AMED, Web of Science and Google Scholar using keywords including ‘mindfulness’, ‘meditation’, and ‘review’, ‘meta-analysis’ or their variations.

Areas of agreement

MBIs are effective for improving many biopsychosocial conditions, including depression, anxiety, stress, insomnia, addiction, psychosis, pain, hypertension, weight control, cancer-related symptoms and prosocial behaviours. It is found to be beneficial in the healthcare settings, in schools and workplace but further research is warranted to look into its efficacy on different problems. MBIs are relatively safe, but ethical aspects should be considered. Mechanisms are suggested in both empirical and neurophysiological findings. Cost-effectiveness is found in treating some health conditions.

Areas of controversy

Inconclusive or only preliminary evidence on the effects of MBIs on PTSD, ADHD, ASD, eating disorders, loneliness and physical symptoms of cardiovascular diseases, diabetes, and respiratory conditions. Furthermore, some beneficial effects are not confirmed in subgroup populations. Cost-effectiveness is yet to confirm for many health conditions and populations.

Growing points

Many mindfulness systematic reviews and meta-analyses indicate low quality of included studies, hence high-quality studies with adequate sample size and longer follow-up period are needed.

Areas timely for developing research

More research is needed on online mindfulness trainings and interventions to improve biopsychosocial health during the COVID-19 pandemic; Deeper understanding of the mechanisms of MBIs integrating both empirical and neurophysiological findings; Long-term compliance and effects of MBIs; and development of mindfulness plus (mindfulness+) or personalized mindfulness programs to elevate the effectiveness for different purposes.
The Hague Judgments Convention and Mainland China-Hong Kong SAR Judgments Arrangement: Comparison and Prospects for Implementation
Authors: Zhang Wenliang , Tu Guangjian
Published: April 2021

The year 2019 saw the arrival of the Hague Judgments Convention and Mainland China-Hong Kong SAR Judgments Arrangement, which is not a coincidence. Both instruments mark a historical culmination and constitute a milestone, at the global level and the at the level of territorial units within a country respectively. With novelties created to avoid the failures shadowing the past Hague Judgments Project, the 2019 Convention reflects the global trend and maximizes the common grounds countries could agree to, though it still falls short of some longstanding expectations. Similarly, the 2019 Arrangement advances judgment circulation between territorial units within China despite that room for further collaboration is still large. In significant respects, the 2019 Arrangement is heavily modelled on the 2019 Convention, while the Arrangement also addresses special concerns of the two regions. Undeniably, it may be another success for the Convention to be able to influence judgments recognition instruments targeting territorial units within a country and show its model effect. Recent years have witnessed Mainland China’s efforts to promote transboundary movement of judgments and its contribution to the arrival of both the 2019 Convention and Arrangement. As an important global player with increasing ambition of claiming more international presence, China will welcome both instruments and the instruments are expected to fare well as desired.
First Dose of BNT162b2 mRNA Vaccine in a Healthcare Worker Cohort Is Associated With Reduced Symptomatic and Asymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection
Authors: Lillie Patrick J , O’Brien Paul , Lawtie Michelle , Jessop Steve , Easom Nicholas J W , Patmore Russell
Published: April 2021

Over the first 2 months of 2021, vaccination coverage of staff at Hull Teaching Hospitals with BNT162b2 increased from 8.3% to 82.5% and was associated with a significant reduction in symptomatic and asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases. The proportion of positive lateral flow tests from asymptomatic screening was maintained over this period.
Development and Validation of the Long Coronavirus Disease (COVID) Symptom and Impact Tools: A Set of Patient-Reported Instruments Constructed From Patients’ Lived Experience
Authors: Tran Viet-Thi , Riveros Carolina , Clepier Bérangère , Desvarieux Moïse , Collet Camille , Yordanov Youri , Ravaud Philippe
Published: April 2021

Background

To develop and validate patient-reported instruments, based on patients’ lived experiences, for monitoring the symptoms and impact of long coronavirus disease (covid).

Methods

The long covid Symptom and Impact Tools (ST and IT) were constructed from the answers to a survey with open-ended questions to 492 patients with long COVID. Validation of the tools involved adult patients with suspected or confirmed coronavirus disease 2019 (COVID-19) and symptoms extending over 3 weeks after onset. Construct validity was assessed by examining the relations of the ST and IT scores with health-related quality of life (EQ-5D-5L), function (PCFS, post-COVID functional scale), and perceived health (MYMOP2, Measure yourself medical outcome profile 2). Reliability was determined by a test-retest. The “patient acceptable symptomatic state” (PASS) was determined by the percentile method.

Results

Validation involved 1022 participants (55% with confirmed COVID-19, 79% female, and 12.5% hospitalized for COVID-19). The long COVID ST and IT scores were strongly correlated with the EQ-5D-5L (rs = −0.45 and rs = −0.59, respectively), the PCFS (rs = −0.39 and rs = −0.55), and the MYMOP2 (rs = −0.40 and rs = −0.59). Reproducibility was excellent with an interclass correlation coefficient of 0.83 (95% confidence interval .80 to .86) for the ST score and 0.84 (.80 to .87) for the IT score. In total, 793 (77.5%) patients reported an unacceptable symptomatic state, thereby setting the PASS for the long covid IT score at 30 (28 to 33).

Conclusions

The long covid ST and IT tools, constructed from patients’ lived experiences, provide the first validated and reliable instruments for monitoring the symptoms and impact of long covid.
Acquisition of Ciprofloxacin Resistance Among an Expanding Clade of β-Lactamase–Positive, Serogroup Y Neisseria meningitidis in the United States
Authors: Potts Caelin C , Retchless Adam C , McNamara Lucy A , Marasini Daya , Reese Natashia , Swint Stephanie , Hu Fang , Sharma Shalabh , Blain Amy E , Lonsway David , Karlsson Maria , Hariri Susan , Fox LeAnne M , Wang Xin ,   Antimicrobial-Resistant Neisseria meningitidis Team, Dhungana Nirmala , Gabrio-Brannon Ryan , Kyle Jennifer , Martin Brittany , Campos Joseph , Hanisch Benjamin , Taormina Gillian , Barnes Meghan , Moore Ashley , Dominguez Catherine E , Lunquest Kristy , Patel Ami A , Torpey David , Hannagan Susan , Keating Page , Li Sandy , Albertson Justin , Fleming Wayne , Russell Christina , Sanders Kelsey , DeBolt Chas , Graff Nicholas , Lam Esther
Published: April 2021

Background

Penicillin and ciprofloxacin are important for invasive meningococcal disease (IMD) management and prevention. IMD cases caused by penicillin- and ciprofloxacin-resistant Neisseria meningitidis containing a ROB-1 β-lactamase gene (blaROB-1) and a mutated DNA gyrase gene (gyrA) have been recently reported in the United States.

Methods

We examined 2097 meningococcal genomes collected through US population-based surveillance from January 2011 to February 2020 to identify IMD cases caused by strains with blaROB-1- or gyrA-mediated resistance. Antimicrobial resistance was confirmed phenotypically. The US isolate genomes were compared to non-US isolate genomes containing blaROB-1. Interspecies transfer of ciprofloxacin resistance was assessed by comparing gyrA among Neisseria species.

Results

Eleven penicillin- and ciprofloxacin-resistant isolates were identified after December 2018; all were serogroup Y, sequence type 3587, clonal complex (CC) 23, and contained blaROB-1 and a T91I-containing gyrA allele. An additional 22 penicillin-resistant, blaROB-1- containing US isolates with wild-type gyrA were identified from 2013 to 2020. All 33 blaROB-1-containing isolates formed a single clade, along with 12 blaROB-1-containing isolates from 6 other countries. Two-thirds of blaROB-1-containing US isolates were from Hispanic individuals. Twelve additional ciprofloxacin-resistant isolates with gyrA T91 mutations were identified. Ciprofloxacin-resistant isolates belonged to 6 CCs and contained 10 unique gyrA alleles; 7 were similar or identical to alleles from Neisseria lactamica or Neisseria gonorrhoeae.

Conclusions

Recent IMD cases caused by a dual resistant serogroup Y suggest changing antimicrobial resistance patterns in the United States. The emerging dual resistance is due to acquisition of ciprofloxacin resistance by β-lactamase–containing N. meningitidis. Routine antimicrobial resistance surveillance will effectively monitor resistance changes and spread.
Can Solar Energy Fuel Pollinator Conservation?
Authors: Dolezal Adam G , Torres Jacob , O’Neal Matthew E
Published: April 2021

As the expansion of solar power spreads through much of the United States, members of the solar industry are working to change how solar energy facilities are designed and presented to the public. This includes the addition of habitat to conserve pollinators. We highlight and discuss ongoing efforts to couple solar energy production with pollinator conservation, noting recent legal definitions of these practices. We summarize key studies from the field of ecology, bee conservation, and our experience working with members of the solar industry (e.g., contribution to legislation defining solar pollinator habitat). Several recently published studies that employed similar practices to those proposed for solar developments reveal features that should be replicated and encouraged by the industry. These results suggest the addition of native, perennial flowering vegetation will promote wild bee conservation and more sustainable honey beekeeping. Going forward, there is a need for oversight and future research to avoid the misapplication of this promising but as of yet untested practice of coupling solar energy production with pollinator-friendly habitat. We conclude with best practices for the implementation of these additions to realize conservation and agricultural benefits.
Adverse functional remodelling of the subpulmonary left ventricle in patients with a systemic right ventricle is associated with clinical outcome
Authors: Santens Béatrice , Helsen Frederik , Van De Bruaene Alexander , De Meester Pieter , Budts Anne-Laure , Troost Els , Moons Philip , Claus Piet , Rega Filip , Bogaert Jan , Budts Werner
Published: April 2021

Aims

Early recognition of adverse remodelling is important since outcome is unfavorable once patients with a systemic right ventricle (sRV) become symptomatic. We aimed assessing prognostic markers linked to short-term clinical evolution in this population.

Methods and results

Thirty-three patients (76% male) with sRV (atrial switch repair for D-transposition of the great arteries and congenitally corrected transposition of the great arteries) underwent detailed phenotyping including exercise cardiac magnetic resonance and were followed over mean follow-up time of 3 years. Mean age was 40 ± 8 (range 26–57) years at latest follow-up. Adverse outcome was a composite of heart failure (HF) and tachyarrhythmia. Descriptive statistics and univariate cox regression analyses were performed. When compared with baseline: (i) most patients remained in New York Heart Association functional class I (76%), (ii) the degree of severity of the systemic atrioventricular valve regurgitation rose, and (iii) more electrical instability was documented at latest follow-up. Six (18%) of a total of 9 events were counted as first cardiovascular events (9% HF and 9% arrhythmia). NT-proBNP, oxygen pulse, left ventricle end-diastolic volume index (LVEDVi), and stroke volume index (SVi) of the subpulmonary left ventricle (LV) both in rest and at peak exercise were significantly associated with the first cardiovascular event.

Conclusion

NT-proBNP was by far the best prognostic marker for clinical outcome. Adverse remodelling with increase of LVEDVi and SVi of the subpulmonary LV at rest and during exercise were associated with worse clinical outcome. We theorize that remodelling of the subpulmonary ventricle might be an early sign of a failing sRV circulation.
EACVI survey on the evaluation of left ventricular diastolic function
Authors: Sitges Marta , Ajmone Marsan Nina , Cameli Matteo , D’Andrea Antonello , Carvalho Ricardo Fontes , Holte Espen , Michalski Blazej , Podlesnikar Tomaz , Popescu Bogdan A , Schulz-Menger Jeanette , Stankovic Ivan , Haugaa Kristina H , Dweck Marc R
Published: April 2021

Aims

The aim of this study is to analyse how current recommendations on left ventricular (LV) diastolic function assessment have been adopted. Identifying potential discrepancies between recommendations and everyday clinical practice would enable us to better understand and address the remaining challenges in this controversial and complex field.

Methods and results

A total of 93 centres, mainly from tertiary care settings, responded to the survey. More than three-quarters (77%) of centres follow the 2016 ASE/EACVI recommendations for LV diastolic function evaluation in patients with preserved ejection fraction based upon e′, E/e′, tricuspid regurgitation velocity, and left atrial (LA) volume. These recommendations were generally preferred to the previous 2009 version. Many centres also consider strain assessments in the LV (48%) and left atrium (53%) as well as diastolic stress echocardiography (33%) to be useful as additional assessments of LV diastolic function. Echocardiographic assessments of LV diastolic function were used frequently to guide therapy in 72% of centres.

Conclusion

There is widespread adoption of current recommendation on the evaluation of LV diastolic function and these are frequently used to guide patient management. Many centres now also consider LV and LA strain assessments useful in the clinical assessment of diastolic function. These may be considered in future recommendations.
Left anterior descending/right coronary artery bifurcation angioplasty in a rare case of single coronary artery: a case report
Authors: Prasad Krishna , Chhikara Sanya , Kumar Mahesh Nalin , Gupta Ankush
Published: April 2021

Background

Single coronary artery (SCA) is a rare congenital coronary anomaly with incidence of 8–66 per 100 000 cases. Percutaneous coronary intervention (PCI) in patients with SCA is technically challenging. This is a case of bifurcation angioplasty involving left anterior descending/right coronary artery (LAD/RCA) in a patient with SCA and 1-year follow-up with computed tomography coronary angiography (CTCA).

Case summary

A 52-year-old female with history of PCI to LAD 4 months back, presented with non-ST-elevation myocardial infarction. Coronary angiogram showed 90% stenosis in mid-LAD, distal to the previous stent and proximal to an anomalously originating RCA from mid-LAD. She was planned for LAD/RCA provisional bifurcation angioplasty and a drug-eluting stent was deployed in LAD across RCA, following which patient developed angina with ischaemic electrocardiogram (ECG) changes due to significant pinching of RCA. Using Reverse crush technique, RCA was stented successfully with resolution of angina and ECG changes. At 1-year follow-up, patient is in New York Heart Association class I with normal left ventricular function and patent LAD/RCA bifurcation stent on CTCA.

Discussion

SCA poses a great challenge to interventional cardiologists during PCI, especially in the event of a complication. Detailed anatomical knowledge, appropriate hardware and operator expertise are the key factors for successful PCI of SCA. This is, to the best of our knowledge, the first case report of bifurcation angioplasty of LAD/RCA in a rare case of SCA. This case also describes the use of reverse crush technique as a bailout strategy during provisional bifurcation angioplasty.