bluuebunny/crossref_metadata_2025 huggingface dataset:
Chiral flows can induce neck formation in viscoelastic surfaces
Authors: de Kinkelder E M , Fischer-Friedrich E , Aland S
Published: April 2023

The cell cortex is an active viscoelastic self-deforming sheet at the periphery of animal cells. It constricts animal cells during cell division. For some egg cells, the actomyosin cortex was shown to exhibit counter-rotating chiral flows along the axis of division. Such chiral surface flows were shown to contribute to spatial rearrangements and left-right symmetry breaking in developing organisms. In spite of this prospective biological importance, the effect of chiral forces on the flows and emergent shape dynamics of a deformable surface are completely unknown. To shed a first light on that matter, we present here a numerical study of an axisymmetric viscoelastic surface embedded in a viscous fluid. We impose a generic counter-rotating force field on this surface and study the resulting chiral flow field and shape dynamics for various surface mechanical parameters. Notably, we find that the building of a neck, as is observed during cell division, occurs if the surface contains a strong shear elastic component. Furthermore, we find that a large areal relaxation time results in flows towards the equator of the surface. These flows assist the transport of a surface concentration during the formation of a contractile ring. Accordingly, we show that chiral forces by themselves can drive pattern formation and stabilise contractile rings at the equator. These results provide first mechanistic evidence that chiral flows can play a significant role to orchestrate cell division.
Application of differential equation in the field of acoustic
Authors: Shafique Sajid , Hina Nazish , Rana Muhammad Afzal , Bano Ambreen
Published: April 2023

The current study examines a classification of physical problems involving the attenuation and propagation of structure and fluid-coupled acoustic waves in a discontinuous waveguide. In acoustics, the response of sound to boundaries is important. Therefore, it is expected that all of the discontinuous waveguide’s boundaries have the same walls, which can be either hard or impedance. The impedance and hard walls of the waveguide are mathematically modeled with respective Robin and Neumann boundary conditions together with the second-order field differential equation. The physical challenge is solved using the mode-matching (MM) approach, which also matches the continuity criteria for the acoustic pressure and normal velocities at matching connections. Transmission loss and powers scattering graphs against various frequencies and waveguides dimension parameters are shown to evaluate how well the waveguide predicts the sound to enhance or attenuate for both fluid and structure-borne modes incidents. By reconstructing the matching continuity requirements at matching junctions and using the conserved power identity, the accuracy of the derived algebra is confirmed. The current study has significant implications for improving sound quality for audible applications.
In-depth insight of thermodynamic and kinetic barrier for computation of nucleation rate and interfacial energy of ultra-small Gd2O3 nanoclusters utilizing non-isothermal thermogravimetric models
Authors: Verma Vivek Kumar , Sabbarwal Shivesh , Srivastava Prachi , Kumar Manoj
Published: April 2023

Determination of temperature-dependent nucleation rate is a crucial parameter to accessing the kinetic and thermodynamic barrier linked with developing subatomic-sized nuclei, which tend to restrain the nucleation process. In this study, we exclusively compute the nucleation rate, thermodynamic parameters, and interfacial energy of ultra-small gadolinium oxide nanoclusters at high temperatures. Here, the apparent value of activation energy (Ea.) and pre-exponential kinetic factor (Aa) was precisely computed by utilizing the most accurate Vyazovkin advanced and KAS iso-conversional method, which was further exploited to estimate the thermodynamic parameters, nucleation rate, and interfacial energy of ∼1 nm-sized gadolinium nanoclusters, in the temperature ranging from 555 to 780 K by appraising thermogravimetric data. The obtained Z (α) master plot suggested the existence of random nucleation within the BSA matrix of Gd2O3 nanoclusters at high temperatures over a specified conversion value. Additionally, four mathematical models were proposed using the above finding to interpret the nucleation rate and interfacial energy concerning high temperature and specified conversion points for the first time.
Sharp turns in axion monodromy: primordial black holes and gravitational waves
Authors: Bhattacharya Sukannya , Zavala Ivonne
Published: April 2023

Large turns in multifield inflation can lead to a very rich phenomenology, but are
difficult to realise in supergravity, and typically require large field space curvatures. In this
work, we present a mechanism to realise multiple sharp turns, and therefore strong non-geodesic
trajectories, from transient violations of slow-roll without the requirement of large field space
curvatures in supergravity inflation. Such turning rates can strongly source the adiabatic
fluctuations, resulting in an enhanced scalar power spectrum with resonant features and a large
peak amplitude. If the growth of the scalar power spectrum at small scales is large enough,
primordial black holes can be produced in abundance. These large scalar fluctuations induce a
characteristic large spectrum of gravitational waves for a wide range of frequencies, which
inherits the resonant features. We illustrate this mechanism in a supergravity model of axion
monodromy, which provides the first concrete model to realise such resonant features.The model can
sustain inflation for around 60 e-folds, leading to considerable production of very light
primordial black holes, and large gravitational wave spectra, which could be detectable by
multiple upcoming gravitational wave surveys. For the set of parameter we consider, large
oscillations occur at all scales. This represents a challenge for the model at large scales and
motivates further investigation to reconcile this class of models with Planck data.
Optimized monophasic pulses with equivalent electric field for rapid-rate transcranial magnetic stimulation
Authors: Wang Boshuo , Zhang Jinshui , Li Zhongxi , Grill Warren M , Peterchev Angel V , Goetz Stefan M
Published: April 2023

Objective. Transcranial magnetic stimulation (TMS) with monophasic pulses achieves greater changes in neuronal excitability but requires higher energy and generates more coil heating than TMS with biphasic pulses, and this limits the use of monophasic pulses in rapid-rate protocols. We sought to design a stimulation waveform that retains the characteristics of monophasic TMS but significantly reduces coil heating, thereby enabling higher pulse rates and increased neuromodulation effectiveness. Approach. A two-step optimization method was developed that uses the temporal relationship between the electric field (E-field) and coil current waveforms. The model-free optimization step reduced the ohmic losses of the coil current and constrained the error of the E-field waveform compared to a template monophasic pulse, with pulse duration as a second constraint. The second, amplitude adjustment step scaled the candidate waveforms based on simulated neural activation to account for differences in stimulation thresholds. The optimized waveforms were implemented to validate the changes in coil heating. Main results. Depending on the pulse duration and E-field matching constraints, the optimized waveforms produced 12%–75% less heating than the original monophasic pulse. The reduction in coil heating was robust across a range of neural models. The changes in the measured ohmic losses of the optimized pulses compared to the original pulse agreed with numeric predictions. Significance. The first step of the optimization approach was independent of any potentially inaccurate or incorrect model and exhibited robust performance by avoiding the highly nonlinear behavior of neural responses, whereas neural simulations were only run once for amplitude scaling in the second step. This significantly reduced computational cost compared to iterative methods using large populations of candidate solutions and more importantly reduced the sensitivity to the choice of neural model. The reduced coil heating and power losses of the optimized pulses can enable rapid-rate monophasic TMS protocols.
Phase diagram of the half-filled Anderson-Hubbard model at finite temperature
Authors: Yen Nguyen Thi Hai , Tuan Hoang Anh
Published: April 2023

We study metal-insulator phase diagram in the half-filled disordered Hubbard model at finite temperature. We calculate the averaged local density of states at the Fermi level and the site occupation as a function of the on-site energy at finite temperature by using typical medium theory with an impurity solver of equation of motion method. Although the metallicity in the correlated metallic region changes with temperature change, the phase diagram is almost temperature independent. We find fairly good agreement between our site occupation and those obtained by the typical medium method with other impurity solver.
Flexural properties of porcupine quill-inspired sandwich panels
Authors: Tee Yun Lu , Nguyen-Xuan H , Tran Phuong
Published: April 2023

This paper presents the bending behaviour of the porcupine quill and bioinspired Voronoi sandwich panels, aiming to explore the effect of geometrical design on the bending performance of the inspired structures. Through the x-ray micro-computed tomography, the internal morphology of the quill is explored. The longitudinal cross-section of the porcupine quill revealed a functionally graded design in the foam structure. Based on this observation, Voronoi sandwich panels are designed by incorporating the Voronoi seed distribution strategy and gradient transition design configurations. Porcupine-inspired sandwich panels with various core designs are fabricated via material jetting technique and tested under three-point bending condition. Results show that the sample failed at the bottom face panels for uniform sandwich panels, whereas graded samples failed in the core panel. The bending behaviour developed via simulation software shows a good agreement with the experimental results. The parametric study provides insights into structural designs for engineering applications, particularly in the aerospace and automobile industries.
Skillful prediction of UK seasonal energy consumption based on surface climate information
Authors: Li Samuel , Sriver Ryan , Miller Douglas E
Published: April 2023

Climate conditions affect winter heating demand in areas that experience harsh winters. Skillful energy demand prediction provides useful information that may be a helpful component in ensuring a reliable energy supply, protecting vulnerable populations from cold weather, and reducing excess energy waste. Here, we develop a statistical model that predicts winter seasonal energy consumption over the United Kingdom using a multiple linear regression technique based on multiple sources of climate information from the previous fall season. We take the autumn conditions of Arctic sea-ice concentration, stratospheric circulation, and sea-surface temperature as predictors, which all influence North Atlantic oscillation (NAO) variability as reported in a previous study. The model predicts winter seasonal gas and electricity consumption two months in advance with a statistically significant correlation between the predicted and observed time series. To extend the analysis beyond the relatively short time scale of gas and electricity data availability, we also analyze predictability of an energy demand proxy, heating degree days (HDDs), for which the model also demonstrates skill. The predictability of energy consumption can be attributed to the predictability of the NAO and the significant correlation of energy consumption with surface air temperature, dew point depression, and wind speed. We further found skillful prediction of these surface climate variables and HDDs over many areas where the NAO is influential, implying the predictability of energy demand in these regions. The simple statistical model demonstrates the usefulness of fall climate observations for predicting winter season energy demand prediction with a wide range of potential applications across energy-related sectors.
Quantum coherence as asymmetry from complex weak values
Authors: Budiyono Agung , Agusta Mohammad K , Nurhandoko Bagus E B , Dipojono Hermawan K
Published: April 2023

Quantum coherence as an asymmetry relative to a translation group generated by a Hermitian operator, is a necessary resource for the quantum parameter estimation. On the other hand, the sensitivity of the parameter estimation is known to be related to the imaginary part of the weak value of the Hermitian operator generating the unitary imprinting of the parameter being estimated. This naturally suggests a question if one can use the imaginary part of the weak value to characterize the coherence as asymmetry. In this work, we show that the average absolute imaginary part of the weak value of the generator of the translation group, maximized over all possible projective measurement bases, can be used to quantify the coherence as asymmetry relative to the translation group, satisfying certain desirable requirements. We argue that the quantifier of coherence so defined, called translationally-covariant (TC) w-coherence, can be obtained experimentally using a hybrid quantum–classical circuit via the estimation of weak value combined with a classical optimization procedure. We obtain upper bounds of the TC w-coherence in terms of the quantum standard deviation, quantum Fisher information, and the imaginary part of the Kirkwood–Dirac quasiprobability. We further obtain a lower bound and derive a relation between the TC w-coherences relative to two generators of translation group taking a form analogous to the Kennard–Weyl–Robertson uncertainty relation.
Study on PSA method applied to SSC aging sensitive screening and classification in nuclear power plant
Authors: Wang Handing , Li Qiongzhe
Published: April 2023

In order to extend the operation license of nuclear power plant, the nuclear safety during the extended service life must be considered, so as to ensure that the nuclear safety level of nuclear power unit during the extended service life is not lower than that of the original design life. PSA technology can be used to establish an aging PSA model for nuclear power plants during the license extension period, so as to evaluate the impact of SSC aging on the overall safety of nuclear power plants and verify that it can still meet the original design standards. Based on this, the SSC screening analysis method applied to aging PSA of nuclear power plant is put forward. By considering trend analysis, aging failure mode and impact analysis, risk importance analysis, the decision matrix of SSC screening for nuclear power plant is established on the basis of three analysis methods, and a feasible method is established for selecting aging and safety important components. This work also lays a technical foundation for the risk management of nuclear power plants in the license extension stage.
Study on economical efficiency of ocean energy generation in China
Authors: Zhang Cailin , Li Xin , Ma Changlei , Li Meng
Published: April 2023

Ocean energy, as a kind of renewable resource, plays an important role in China’s low-carbon development and meeting its goal of “carbon peaking and carbon neutrality”. The paper aims to calculate the cost of ocean power generation in China and make a medium and long-term forecast. Meanwhile, the offshore wind power development experience and the Levelized Cost of Energy (LCOE) cost pricing model is used for analysis and verification. The results shows that it features a high cost without economical efficiency in the initial stage; With the continuous expansion of installed capacity, the cost will be significantly lowered but the economical efficiency is moderate; the cost will fall significantly when the installed capacity reaches to a 100 MW level, and it has strong economical efficiency. The government should provide policy and financial support for ocean power generation industry; enterprises need to strengthen technological innovation and complete the industrial chain to improve the economical efficiency of scale utilization.
Study on direct parallel charging of lithium-ion battery and supercapacitor
Authors: Dong Ao , Ma Ruifei , Deng Yelin
Published: April 2023

Currently, there are few studies on hybrid system charging, and the existing ones rely on many power electronic components to charge lithium-ion battery and supercapacitor, respectively. This paper mainly focuses on the direct parallel charging of lithium-ion battery and supercapacitor, which has simple structure and low cost. However, the capacity of the hybrid system can not be fully utilized due to the unreasonable current distribution during charging. This paper proposes a method that improves the charging effect: constant current charging under fine tuning the resistance distribution of battery branch and supercapacitor branch (CCFTR). The results show that although the charging time is increased slightly with the CCFTR, the charging capacity can increase significantly. Compared with the untreated constant current charging (CC), the charging time is only prolonged by 6.77 minutes with the CCFTR (50mΩ) at 22A (2.75C), but the charging capacity is increased by 48.4%, reaching 95.1% of the rated capacity. And the CCFTR can dramatically prolong the battery life. The effect is better under higher current. Compared to the CC with the same charging current, the CCFTR can extend the battery life by 11.37% at 2.75C and 26.02% at 3.75C.
Application and comparison of multiple machine learning models for the prediction of the laminar burning velocity for CH3OH/H2/air mixtures
Authors: Zheng Kangxue , Wang Xuehui , Wang Jian
Published: April 2023

Recent investigations have indicated that co-firing CH3OH with H2 is a promising approach to develop a carbon-neutral energy system. However, accurate measurements of laminar burning velocities over a wide range of equivalence ratios, H2 mole fractions, pressures and temperatures are complicated and may not available. Hence, this research deeply investigates the application of several machine learning models in predicting the laminar burning velocities of CH3OH/H2 blended fuels. Results denoted that Random Forest Regressor is the most persuasive model based on a thorough comparison, as indicated by the correlation coefficient of 0.99707.
Operation control and optimization of high efficiency hot primary air temperature adjustment device
Authors: Xie Fuyou , Ren Yanhui , Wang Ning , Xue Ligang , Wei Houyu
Published: April 2023

Aiming at the problems existing in the control logic of the current hot primary air temperature adjustment device, such as adjustment lag, poor adjustment quality, deviation of the pulverizing system operation from the normative value and insufficient energy-saving effect in the adjustment process, a standard-based calculation method was proposed. It is a logical optimization scheme that dynamically adapts to the moisture content of raw coal and the coal volume of the pulverized. It has the advantages of faster adjustment speed, high system energy saving effect, and ensures the standard operation of the coal mill.
Research on technical route and economic calculation of solar assisted carbon capture system
Authors: Ma Lin , Zhang Li , Zhang Xinyi
Published: April 2023

This paper takes a 600MW supercritical unit as the research object, and studies the technical route and economic situation of solar photothermal system as the heat source of reboiler of carbon capture system. Taking Monoethanolamine (MEA) as the research object to analyse its desorption energy consumption characteristics, the calculation results show that the carbon capture and regeneration energy consumption of the system is 3.90Gj/t CO2, calculated by the CO2 absorption rate of 85%. Three technical routes of solar assisted carbon capture systems are proposed, and the main thermal economic indexes of the two methods, such as unit coal consumption and thermal efficiency, using the fifth stage extraction steam as an independent heat source and cooperating with the solar photothermal system, are calculated and compared respectively. Based on this, the influence of investment cost and collector area on CO2 emission reduction cost and coal consumption is analysed. The results show that after adding the solar thermal system, the coal consumption of the unit is reduced by 2.5g/(kw) compared with the pure steam extraction heating unit and the thermal efficiency is increased by 0.9%. The CO2 emission reduction cost has a positive correlation trend with the investment cost, and the unit coal consumption has a negative correlation trend with the increase of the collector area.
Blue energy in China: exploring the prospects and development path for marine renewable energy industries
Authors: Wang Ji , Wu Wenjing , Wang Haifeng
Published: April 2023

Marine renewable energy has the characteristics of green and clean, wide distribution, nearby consumption, accurate prediction, and customization on demand. It can provide green energy solutions according to the needs of islands, ocean economic development, and energy consumption of offshore equipment. China has an excellent marine renewable energy resource. Facing great pressure on climate change and energy crisis, the Chinese Government has been showing a strong commitment to marine renewable energy. In this paper, we describe the resources distribution and technology status of marine renewable energy, analyse marine renewable energy strategies in China, and assessment and advices are given for each energy categories. This paper provides an overview of marine renewable energy industries, technology, policy, development trend, structure of industrial chains, challenges, opportunities in China, and provides recommendations for the development of marine renewable energy.
Urban ecological quality and statistical correlation analysis based on satellite remote sensing
Authors: Ma Mingyue , Xu Guochang , Lv Zhiping , Chen Shujun , Li Hanyu , Zhang Guangzong
Published: April 2023

Jiangsu Province is an area with active economic and social development. With the advancement of urbanization, ecological issues have become a hot spot in the region. Objectively and quantitatively assessing spatial-temporal environmental quality changes is crucial for environmental protection and policymaking. Remote sensing is a very effective ground-based information acquisition tool for long-term ecological analysis. Thus, this study uses remote sensing to evaluate the quality of the ecological environment in Jiangsu Province. The Remote Sensing Ecological Index (RSEI) from 1990 to 2020 is calculated on the Google Earth Engine platform. The spatial-temporal changes and spatial auto-correlation of the ecological environment quality are evaluated. The results show that from 1990 to 2020, the ecological status shows a downward-rising-flat trend. The RSEI has decreased from 0.4677(1990) to 0.4524(2005) and then increased from 0.4524(2005) to 0.4562(2020). The spatial auto-correlation analysis show that the spatial distribution of ecological quality is positively correlated. The clustering map of RSEI spatially correlated local indicators show that the hot points are mainly located in the north and middle parts of the study area. The cold points are mainly distributed in the southern Yangtze River coastal urban cluster. Such a technique is not limited by time and space, so it can be widely used in monitoring and protecting the ecological environment.
Effects of land use change on the ecosystem service value – A case study of Jiulongjiangkou, Fujian, China, from 2013 to 2021
Authors: Liu Zhong , Zhou Jinlan , Zhu Lirong , Lin Chih-Wei
Published: April 2023

In this study, we utilized the dynamic changes in land use and ecosystem service value to provide ecological security protection and realize the coordinated development of ecosystem service functions for the Jiulongjiangkou Wetland Reserve. We counted the land use changes and calculated the ecological service value of the Jiulongjiangkou by using eCognition 9.0, ArcMap 10.2, Fragstats 4.2, and other software based on the remote sensing image from 2013 to 2021 with five phases, which were captured by Landsat-8 satellite. The results showed that the land use type of Jiulongjiangkou City changed significantly and was affected by human activities, in which the wetland area decreased by 8.61 km2, a decrease of 8.5%. In the past ten years, the value of ecosystem service has not increased, which decreased by 1.3*108 RMB in 2021 compared with 2013. In the future, we should continue to increase the protection of forest lands and waters, maintain the stability of the ecosystem of protected areas, rationally plan the land for construction, actively develop green agriculture, and steadily enhance the value of ecosystem service.
Enhanced removal of triclosan from contaminated water by indigenous isolate Burkholderia sp. L303
Authors: Qiu Lan , Guo Xiaoyuan , Shim Hojae
Published: April 2023

Triclosan (TCS), one of the most widely used antimicrobial agents, is frequently detected at wastewater treatment plants and environmental matrices including soil, water, sediment, and biota samples. In this study, a TCS-degrading bacterium was isolated from local activated sludge and identified asBurkholderiasp. L303. Strain L303 could degrade TCS (0.5-8 mg/L) as sole carbon source. The optimal condition was 35°C and pH 7. Thein-vitroassay with the glucose-enriched cells showed the ability of TCS degradation in real water samples, indicating the functional enzyme expressed in the absence of TCS. The bioaugmentation of strain L303 in non-sterile wastewater showed better degradation rate than that in the control groups. The community profiles showed the potential cooperative interactions between strain L303 and indigenous bacteria, thereby enhancing the TCS degradation in the real polluted water. The finding of this study could facilitate in developing appropriate bioaugmentation strategy by using live bacteria or active enzyme and in designing beneficial community interactions within native and external species for treating TCS-laden waters.
Analysis and research on the characteristics of pollutants discharged from the separate storm pump station
Authors: Yuan Wenqi
Published: April 2023

The separate storm pump station can reduce the overflow pollution in rainy days and reduce the impact on the water environment. However, before or after rainfall, the impact of the discharge of diversion rainwater pump station on the water environment is still prominent, which has become one of the important reasons restricting the improvement of water environment pollution. This paper investigates the diversion rainwater pump stations in Shanghai, analyzes the discharge flow and pollution law of the diversion rainwater pump stations according to the operation data, and studies the characteristics, causes and effects of discharge pollution. Therefore, to provide support for the pollutant discharge control of the diversion rainwater pump station.
Study on the adsorption characteristics of lead in soil by biochar from co-pyrolysis of rice straw and sludge
Authors: Wang Hui , Ge Shifu , Ye Lei , Zhou Cailin
Published: April 2023

The adsorption kinetics and short-term soil adsorption experiments were carried out for the biochar (mixed charcoal) prepared by co-pyrolysis of rice straw and sludge. The results showed that the specific surface area and total pore volume of co-pyrolysed biochar were significantly increased compared with sludge pyrolysis biochar. In the lead solution adsorption experiment, the removal rate of lead ions in the solution reached 99.34% using mixed-burning biochar produced at 600 °C for 24h, and the unit mass adsorption capacity was 64.57 mg/g. In the soil adsorption experiment, 12 g/kg of mixed charcoal was added to lead-contaminated soil, and the leaching toxicity and bioavailability of lead-contaminated soil after stabilization for 30 days decreased by 45.3% and 37.0%, respectively. The soil pH value with 12 g/kg of mixed charcoal added within 30 days fluctuated between 7.03 and 7.12, and no acid or alkaline pollution was generated. Co-pyrolysed biochar can effectively reduce the leaching toxicity and bioavailability of lead in soil. For soil with a lead pollution concentration of less than 1600 mg/kg, adding 12 to 16 g/kg of co-pyrolysed biochar produced at 600 °C can achieve a satisfactory repair effect.
Propagation of surface magnetoplasmon polaritons in a symmetric waveguide with two-dimensional electron gas
Authors: GAO Mingxiang , WANG Baojun , GUO Bin
Published: April 2023

The properties of surface magnetoplasmon polaritons (SMPPs) in a symmetric structure, composed of two semi-infinite regions of high-density two-dimensional electron gas (2DEG) separated by a thin film in Voigt configuration, are investigated. The normal and absorption dispersion relations for the transverse magnetic polarization are derived by correlating Maxwell’s equation and the boundary conditions. It is demonstrated that the features of SMPPs are greatly influenced by the external magnetic field, collision frequency of 2DEG, the dielectric constant, and the thickness of the thin film, suggesting that the locations and propagation lengths of SMPPs can be governed accordingly. It is shown that the symmetry of the physical geometry preserves the symmetry of the dispersion relations of SMPPs. Furthermore, it is discovered that as the external magnetic field increases, the penetration depth of SMPPs decreases, while their energy loss reduces, implying that plasmons can propagate for longer distances. Additionally, it is observed that SMPPs in the symmetric configuration have a longer lifetime than those in the asymmetric configuration.
Spectrally adapted physics-informed neural networks for solving unbounded domain problems
Authors: Xia Mingtao , Böttcher Lucas , Chou Tom
Published: April 2023

Solving analytically intractable partial differential equations (PDEs) that involve at least one variable defined on an unbounded domain arises in numerous physical applications. Accurately solving unbounded domain PDEs requires efficient numerical methods that can resolve the dependence of the PDE on the unbounded variable over at least several orders of magnitude. We propose a solution to such problems by combining two classes of numerical methods: (i) adaptive spectral methods and (ii) physics-informed neural networks (PINNs). The numerical approach that we develop takes advantage of the ability of PINNs to easily implement high-order numerical schemes to efficiently solve PDEs and extrapolate numerical solutions at any point in space and time. We then show how recently introduced adaptive techniques for spectral methods can be integrated into PINN-based PDE solvers to obtain numerical solutions of unbounded domain problems that cannot be efficiently approximated by standard PINNs. Through a number of examples, we demonstrate the advantages of the proposed spectrally adapted PINNs in solving PDEs and estimating model parameters from noisy observations in unbounded domains.
DeepMicroGen: a generative adversarial network-based method for longitudinal microbiome data imputation
Authors: Choi Joung Min , Ji Ming , Watson Layne T , Zhang Liqing
Published: April 2023

Motivation

The human microbiome, which is linked to various diseases by growing evidence, has a profound impact on human health. Since changes in the composition of the microbiome across time are associated with disease and clinical outcomes, microbiome analysis should be performed in a longitudinal study. However, due to limited sample sizes and differing numbers of timepoints for different subjects, a significant amount of data cannot be utilized, directly affecting the quality of analysis results. Deep generative models have been proposed to address this lack of data issue. Specifically, a generative adversarial network (GAN) has been successfully utilized for data augmentation to improve prediction tasks. Recent studies have also shown improved performance of GAN-based models for missing value imputation in a multivariate time series dataset compared with traditional imputation methods.

Results

This work proposes DeepMicroGen, a bidirectional recurrent neural network-based GAN model, trained on the temporal relationship between the observations, to impute the missing microbiome samples in longitudinal studies. DeepMicroGen outperforms standard baseline imputation methods, showing the lowest mean absolute error for both simulated and real datasets. Finally, the proposed model improved the predicted clinical outcome for allergies, by providing imputation for an incomplete longitudinal dataset used to train the classifier.

Availability and implementation

DeepMicroGen is publicly available at https://github.com/joungmin-choi/DeepMicroGen.
Characterization and Investigation of Risk Factors for Late-Relapsing Hepatitis After Yellow Fever
Authors: Rezende Izabela Mauricio de , McClure Max A , Pereira Leonardo S , Fradico Jordana R B , Cenachi Adriana R C , Moura Alexandre S , Paladino Luísa L de A , Dutra Maria Rita T , Alves Pedro A , Xavier Marcelo A P , Said Rodrigo F do C , Ramalho Dario B , Gama Thaysa D P , Martins-Filho Olindo A , Monath Thomas P , Teixeira-Carvalho Andréa , Drumond Betânia P , LaBeaud Angelle D ,   for the Yellow Fever Collaborative Group, Castro Bragato Alexandre Maurício , Araújo Argus Leão , de Almeida Faria Flávio Augusto , Penido Indiara , Menezes Letícia , Rabelo Livia Frota , Pamplona Livia , da Cunha Melo Lívia Fulgêncio , Fonte Boa Lívia Soares Coelho , dos Santos Lívia Zignago Moreira , de Paula Ludmila , Marçal Marcelle Cardoso , Albuquerque Natalia Soares , Macedo Rodrigo , Araújo Tayrine
Published: April 2023

Background

Late-relapsing hepatitis after yellow fever (LHep-YF) during the convalescent phase of the disease has been described during recent yellow fever (YF) outbreaks in Brazil. LHep-YF is marked by a rebound in liver enzymes and nonspecific clinical manifestations around 46–60 days after YF symptom onset.

Methods

Here we have characterized the clinical course and risk factors for LHep-YF using data from a representative cohort of patients who survived YF in Brazil, 2017–2018. A total of 221 YF-positive patients were discharged from the infectious disease reference hospital in Minas Gerais and were followed up at 30, 45, and 60 days post–symptom onset.

Results

From 46 to 60 days post–symptom onset, 16% of YF patients (n = 36/221) exhibited a rebound of aminotransferases (aspartate aminotransferase or alanine aminotransferase >500 IU/L), alkaline phosphatase, and total bilirubin levels. Other etiologies of liver inflammation such as infectious hepatitis, autoimmune hepatitis, and metabolic liver disease were ruled out. Jaundice, fatigue, headache, and low platelet levels were associated with LHep-YF. Demographic factors, clinical manifestations, laboratory tests, ultrasound findings, and viral load during the acute phase of YF were not associated with the occurrence of LHep-YF.

Conclusions

These findings provide new data on the clinical course of Late-relapsing hepatitis during the convalescent phase of YF and highlight the need for extended patient follow-up after acute YF.
Lifelong statins for long life in dialysis patients?
Authors: Ebert Thomas , Bárány Peter
Published: April 2023

Dyslipidemia in chronic kidney disease (CKD) contributes to the increasing cardiovascular risk during progression of the disease. Statins reduces the risk of ischemic cardiovascular events in CKD patients not treated with dialysis and treatment is generally recommended in patients above 50 years old. In CKD patients on maintenance dialysis treatment, it is not recommended to initiate statins based on evidence from randomized clinical trials. In an article by Marx et al. in this issue of CKJ, a post hoc analysis of cardiovascular events in the 4D study of dialysis patients with diabetes mellitus shows different time trends for events in statin-treated patients compared with those in the placebo group. Although the numbers of cardiovascular events were not different, the risk increased over time in the placebo group whereas it stabilized after 1.5 years and remained constant in the atorvastatin group. In this Editorial we discuss this analysis in the context of current guidelines and clinical practice in dialysis patients.
Breast Cancer Mass Classification Using Machine Learning, Binary-Coded Genetic Algorithms and an Ensemble of Deep Transfer Learning
Authors: Tiryaki Volkan Müjdat , Tutkun Nedim
Published: April 2023

The diagnosis of breast cancer (BC) as early as possible is crucial for increasing the survival rate. Mammography enables finding the breast tissue changes years before they could develop into cancer symptoms. In this study, machine learning methods for BC mass pathology classification have been investigated using the radiologists’ mass annotations on the screen-film mammograms of the Breast Cancer Digital Repository (BCDR). The performances of precomputed features in the BCDR and discrete wavelet transform followed by Radon transform have been investigated by using four sequential feature selections and three genetic algorithms. Feature fusion from craniocaudal and mediolateral oblique views was shown to increase the performance of the classifier. Mass classification has been implemented by deep transfer learning (DTL) using the weights of ResNet50, NASNetLarge and Xception networks. An ensemble of DTL (EDTL) was shown to have higher classification performance than the DTL models. The proposed EDTL has area under the receiver operating curve (AUC) scores of 0.8843 and 0.9089 for mass classification on the region of interest (ROI) and ROI union datasets, respectively. The proposed EDTL has the highest BC mass classification AUC score on the BCDR to date and may be useful for other datasets.
Differences in Healthcare Utilization in Women with and without Inflammatory Bowel Diseases During Preconception, Pregnancy and Postpartum: A Population-Based Cohort Study
Authors: Tandon Parul , Huang Vivian W , Feig Denice S , Saskin Refik , Maxwell Cynthia , Gao Yiding , Fell Deshayne B , Seow Cynthia H , Snelgrove John W , Nguyen Geoffrey C
Published: April 2023

Background and Aims

Compared to those without inflammatory bowel disease [IBD], women with IBD may have increased healthcare utilization during pregnancy and postpartum, though this remains to be confirmed. We aimed to characterize this healthcare use between these groups.

Methods

Administrative databases were accessed to identify women [aged 18–55 years] with and without IBD who had a live, singleton pregnancy between 2003 and 2018. Differences in emergency department [ED] visits, hospitalizations and prenatal care during 12 months preconception, pregnancy and 12 months postpartum were characterized. Multivariable negative binomial regression was performed to report incidence rate ratios [IRRs] with 95% confidence intervals [95% CIs]. Covariates included maternal age at conception, location of residence, socioeconomic status and maternal comorbidity.

Results

In total, 6163 women with IBD [9158 pregnancies] and 1091 013 women without IBD [1729 411 pregnancies] were included. Women with IBD were more likely to visit the ED [IRR 1.13, 95% CI 1.08–1.18] and be hospitalized [IRR 1.11, 95% CI 1.01–1.21] during pregnancy, and visit the ED [IRR 1.21, 95% CI 1.15–1.27] and be hospitalized [IRR 1.18, 95% CI 1.05–1.32] during postpartum. On unadjusted analysis, women with IBD were more likely to be hospitalized for venous thromboembolic events. There was no difference in healthcare use in preconception. Finally, women with IBD also had a greater number of prenatal visits during pregnancy and were more likely to receive a first-trimester prenatal visit.

Conclusion

Women with IBD have increased healthcare utilization during pregnancy and postpartum. Efforts should be made to increase ambulatory care access during this period, which in turn may reduce this health-services utilization.
Management of Inflammatory Bowel Disease Using E-health Technologies: A Systematic Review and Meta-Analysis
Authors: Kuriakose Kuzhiyanjal Anish J , Nigam Gaurav B , Antoniou George A , Farraye Francis A , Cross Raymond K , Limdi Jimmy K
Published: April 2023

Background and Aims

Technological advances have provided innovative, adaptive, and responsive models of care for inflammatory bowel diseases [IBD]. We conducted a systematic review to compare e-health interventions with standard care in management of IBD.

Methods

We searched electronic databases for randomised, controlled trials [RCT] comparing e-health interventions with standard care for patients with IBD. Effect measures were standardised mean difference [SMD], odds ratio [OR], or rate ratio [RR], calculated using the inverse variance or Mantel–Haenszel statistical method and random-effects models. Version 2 of the Cochrane tool was used to assess the risk of bias. The certainty of evidence was appraised with the GRADE framework

Results

Fourteen RCTs [n = 3111; 1754 e-health and 1357 controls] were identified. The difference in disease activity scores (SMD 0.09, 95% confidence interval [CI]: -0.09-0.28) and clinical remission (odds ratio [OR] 1.12, 95% CI: 0.78-1.61) between e-health interventions and standard care were not statistically significant. Higher quality of life [QoL] [SMD 0.20, 95% CI: 0.05-0.35) and IBD knowledge [SMD 0.23, 95% CI: 0.10-0.36] scores were noted in the e-health group, and self-efficacy levels [SMD -0.09, 95% CI: -0.22-0.05] were comparable. E-health patients had fewer office [RR 0.85, 95% CI: 0.78-0.93] and emergency [RR 0.70, 95% CI: 0.51- 0.95] visits, with no statistically significant difference in endoscopic procedures, total health care encounters, corticosteroid use, and IBD related hospitalisation or surgery. The trials were judged to be at high risk of bias or to have some concerns for disease remission. The certainty of evidence was moderate or low.

Conclusion

E-health technologies may have a role in value-based care in IBD.
Ganglionated plexi ablation in the right atrium for the treatment of cardioinhibitory syncope
Authors: Rebecchi Marco , De Ruvo Ermenegildo , Borrelli Alessio , Sette Antonella , Sgueglia Marianna , Grieco Domenico , Canestrelli Stefano , Politano Alessandro , Panattoni Germana , Licciardello Claudio , Latorre Maria , Panuccio Marco , Mattatelli Antonella , Calò Leonardo
Published: April 2023

Neurocardiogenic syncope, also called vasovagal syncope, represents one of the clinical manifestations of neurally mediated syncopal syndrome. Generally, the prognosis of the cardioinhibitory form of neurocardiogenic syncope is good, but quality of life is seriously compromised in patients who experience severe forms. Drug therapy has not achieved good clinical results and very heterogeneous data come from studies regarding permanent cardiac pacing. In this scenario, the ganglionated plexi ablation has been proposed as an effective and safe method in patients with cardioinhibitory neurocardiogenic syncope, especially in young patients in order to avoid or prolong, as much as possible, the timing of definitive cardiac pacing. Certainly, making this procedure less extensive and limiting the ablation in the right atrium (avoiding the potential complications of a left atrial approach) and at level of anatomical regions of the most important ganglionated plexy, considered ‘gateway’ of the sino-atrial and atrio-ventricular node function (through the recognition of specific endocardial potentials), could be very advantageous in this clinical scenario. Finally, randomized, multicentre, clinical trials on a large population are needed to better understand which is the best ablation treatment (right-only or bi-atrial) and provide evidence for syncope guidelines.
Cardiovascular prevention: sometimes dreams can come true
Authors: Ferrari Roberto , Cimaglia Paolo , Cantone Anna , Serenelli Matteo , Guardigli Gabriele
Published: April 2023

Cardiovascular disease (CVD) is a chronic condition driven by the complex interaction of different risk factors including genetics, lifestyle, environment, etc. which, differently from other pathologies, can be prevented. Treatment of CVD has been inconceivably successful but now it seems that it has reached a plateau suggesting that prevention is the way forward. However, the COVID-19 pandemic has spotted all the limits of the actual health system regarding territorial and, particularly, of preventive medicine. To this end, recently, the SCORE2 risk prediction algorithms, a contemporary model to estimate 10 years risk of CVD in Europe and the new guidelines on prevention have been released. The present review article describes a dream: how prevention of CVD should be addressed in the future. New concepts and paradigms like early genetically personalized and imaging driven risk factors, cardiac risk cartography, measurements of the exposome, estimation of costs of a delayed outcome vs. healthy lifespan, are all addressed. We highlight the importance of technologies and the concept of being engaged in a ‘healthy’ and not just ‘sick’ system as it is today. The concept of ‘clearing house’ with a ‘care health team’ instead of a ‘heart team’ is described. Finally, we articulate the four points necessary for the dream to come true.
Stabilization of vulnerable plaque in the ACS patient: evidence from HUYGENS studies
Authors: Zanda Greca , Varbella Ferdinando
Published: April 2023

The introduction of PCSK9 inhibitors in addition to statin therapy allowed better control of LDL-C plasma levels with a subsequent reduction of cardiovascular events. Human atherosclerosis has been previously considered an irreversible condition; studies firstly based on angiography imaging and secondly with intra-coronary imaging—mainly IVUS based—have demonstrated that lipid-lowering therapy based on statins can stabilize and even reduce atherosclerotic burden of coronary circulation. While plaque stabilization and/or reduction with PCSK9 inhibitors have already been demonstrated in the GLAGOV study, the HUYGENS study showed a positive effect not only on atherosclerotic burden but also on plaque phenotype, with an increased FCT, decrease in maximum lipid arch, and reduction of macrophages infiltration. Further studies need to assess the clinical impact of the reduction of plaques displaying high-risk features with PCSK9 inhibitors.
Autopsy and sudden death
Authors: Thiene Gaetano
Published: April 2023

Our story dates back in the late 70s, when a series of juvenile sudden death (SD) occurred in the Veneto region, north east of Italy. A successful application for a prospective study on young people dying suddenly (<35-year-old, sudden infant death syndrome excluded) was submitted to the regional health authorities, thus implementing a network of collaboration with local anatomic and forensic pathologists, to collect all such events and to gather demographic data. The project is still in progress, and since then, we studied hundreds of consecutive juvenile SD cases, allowing to identify the culprit diseases in the various organs and cardiac structures (aorta, coronary arteries, myocardium, valves, and conduction system). The long-standing Veneto region experience clearly shows that autopsy still plays a pivotal role in the study and prevention of SD and should be carried out regularly. With time, the investigation of SD moved from the classic post-mortem study to molecular autopsy, especially in cases of SD with structurally normal heart. Sudden death prevention in the young has to be faced by an interdisciplinary team, including pathologists, cardiologists, sport physicians, and geneticists, the clinicopathologic correlation method still being the polar star. The game in the fight against SD is still played in the anatomical theatre, the place where ‘death enjoys to save lives’.