bluuebunny/crossref_metadata_2025_split huggingface dataset:
A three-feature prediction model for metastasis-free survival after surgery of localized clear cell renal cell carcinoma
Authors: Mattila Kalle E. , Laajala Teemu D. , Tornberg Sara V. , Kilpeläinen Tuomas P. , Vainio Paula , Ettala Otto , Boström Peter J. , Nisen Harry , Elo Laura L. , Jaakkola Panu M. 
Published: April 2021

AbstractAfter surgery of localized renal cell carcinoma, over 20% of the patients will develop distant metastases. Our aim was to develop an easy-to-use prognostic model for predicting metastasis-free survival after radical or partial nephrectomy of localized clear cell RCC. Model training was performed on 196 patients. Right-censored metastasis-free survival was analysed using LASSO-regularized Cox regression, which identified three key prediction features. The model was validated in an external cohort of 714 patients. 55 (28%) and 134 (19%) patients developed distant metastases during the median postoperative follow-up of 6.3 years (interquartile range 3.4–8.6) and 5.4 years (4.0–7.6) in the training and validation cohort, respectively. Patients were stratified into clinically meaningful risk categories using only three features: tumor size, tumor grade and microvascular invasion, and a representative nomogram and a visual prediction surface were constructed using these features in Cox proportional hazards model. Concordance indices in the training and validation cohorts were 0.755 ± 0.029 and 0.836 ± 0.015 for our novel model, which were comparable to the C-indices of the original Leibovich prediction model (0.734 ± 0.035 and 0.848 ± 0.017, respectively). Thus, the presented model retains high accuracy while requiring only three features that are routinely collected and widely available.
The serotonin transporter gene and female personality variation in a free-living passerine
Authors: Thys Bert , Grunst Andrea S. , Staes Nicky , Pinxten Rianne , Eens Marcel , Grunst Melissa L. 
Published: April 2021

AbstractQuantifying variation in behaviour-related genes provides insight into the evolutionary potential of repeatable among-individual variation in behaviour (i.e. personality). Yet, individuals typically also plastically adjust their behaviour in response to environmental conditions and/or age, thereby complicating the detection of genotype–phenotype associations. Here, using a population of free-living great tits (Parus major), we assessed the association between single nucleotide polymorphisms (SNPs) in the serotonin transporter gene (SERT) and two repeatable behavioural traits, i.e. female-female aggression and female hissing behaviour. For female-female aggression, a trait showing age-related plasticity, we found no evidence for associations withSERTSNPs, even when assessing potential age-dependent effects ofSERTgenotype on aggression. We also found no strong support for associations betweenSERTSNPs and hissing behaviour, yet we identified two synonymous polymorphisms (exon 13 SNP66 and exon 12 SNP144) of particular interest, each explaining about 1.3% of the total variation in hissing behaviour. Overall, our results contribute to the general understanding of the biological underpinning of complex behavioural traits and will facilitate further (meta-analytic) research on behaviour-related genes. Moreover, we emphasize that future molecular genetic studies should consider age-dependent genotype–phenotype associations for behavioural trait (co)variation, as this will vastly improve our understanding of the proximate causes and ultimate consequences of personality variation in natural populations.
Transcriptomic analysis of immune cells in a multi-ethnic cohort of systemic lupus erythematosus patients identifies ethnicity- and disease-specific expression signatures
Authors: Andreoletti Gaia , Lanata Cristina M. , Trupin Laura , Paranjpe Ishan , Jain Tia S. , Nititham Joanne , Taylor Kimberly E. , Combes Alexis J. , Maliskova Lenka , Ye Chun Jimmie , Katz Patricia , Dall’Era Maria , Yazdany Jinoos , Criswell Lindsey A. , Sirota Marina 
Published: April 2021

AbstractSystemic lupus erythematosus (SLE) is an autoimmune disease in which outcomes vary among different racial groups. We leverage cell-sorted RNA-seq data (CD14+ monocytes, B cells, CD4+ T cells, and NK cells) from 120 SLE patients (63 Asian and 57 White individuals) and apply a four-tier approach including unsupervised clustering, differential expression analyses, gene co-expression analyses, and machine learning to identify SLE subgroups within this multiethnic cohort. K-means clustering on each cell-type resulted in three clusters for CD4 and CD14, and two for B and NK cells. To understand the identified clusters, correlation analysis revealed significant positive associations between the clusters and clinical parameters including disease activity as well as ethnicity. We then explored differentially expressed genes between Asian and White groups for each cell-type. The shared differentially expressed genes across cells were involved in SLE or other autoimmune-related pathways. Co-expression analysis identified similarly regulated genes across samples and grouped these genes into modules. Finally, random forest classification of disease activity in the White and Asian cohorts showed the best classification in CD4+ T cells in White individuals. The results from these analyses will help stratify patients based on their gene expression signatures to enable SLE precision medicine.
SARS-CoV-2 shifting transmission dynamics and hidden reservoirs potentially limit efficacy of public health interventions in Italy
Authors: Giovanetti Marta , Cella Eleonora , Benedetti Francesca , Rife Magalis Brittany , Fonseca Vagner , Fabris Silvia , Campisi Giovanni , Ciccozzi Alessandra , Angeletti Silvia , Borsetti Alessandra , Tambone Vittoradolfo , Sagnelli Caterina , Pascarella Stefano , Riva Alberto , Ceccarelli Giancarlo , Marcello Alessandro , Azarian Taj , Wilkinson Eduan , de Oliveira Tulio , Alcantara Luiz Carlos Junior , Cauda Roberto , Caruso Arnaldo , Dean Natalie E. , Browne Cameron , Lourenco Jose , Salemi Marco , Zella Davide , Ciccozzi Massimo 
Published: April 2021

AbstractWe investigated SARS-CoV-2 transmission dynamics in Italy, one of the countries hit hardest by the pandemic, using phylodynamic analysis of viral genetic and epidemiological data. We observed the co-circulation of multiple SARS-CoV-2 lineages over time, which were linked to multiple importations and characterized by large transmission clusters concomitant with a high number of infections. Subsequent implementation of a three-phase nationwide lockdown strategy greatly reduced infection numbers and hospitalizations. Yet we present evidence of sustained viral spread among sporadic clusters acting as “hidden reservoirs” during summer 2020. Mathematical modelling shows that increased mobility among residents eventually catalyzed the coalescence of such clusters, thus driving up the number of infections and initiating a new epidemic wave. Our results suggest that the efficacy of public health interventions is, ultimately, limited by the size and structure of epidemic reservoirs, which may warrant prioritization during vaccine deployment.
Enhanced energy harvesting near exceptional points in systems with (pseudo-)PT-symmetry
Authors: Fernández-Alcázar Lucas J. , Kononchuk Rodion , Kottos Tsampikos 
Published: April 2021

AbstractExceptional point degeneracies, occurring in non-Hermitian systems, have challenged many well established concepts and led to the development of remarkable technologies. Here, we propose a family of autonomous motors whose operational principle relies on exceptional points via the opportune implementation of a (pseudo-)PT-symmetry and its spontaneous or explicit violation. These motors demonstrate a parameter domain of coexisting high efficiency and maximum work. In the photonic framework, they can be propelled by thermal radiation from the ambient thermal reservoirs and utilized as autonomous self-powered microrobots, or as micro-pumps for microfluidics in biological environments. The same designs can be also implemented with electromechanical elements for harvesting ambient mechanical (e.g., vibrational) noise for powering a variety of auxiliary systems. We expect that our proposal will contribute to the research agenda of energy harvesting by introducing concepts from mathematical and non-Hermitian wave physics.
Probing the beam‐induced heating effect inside a transmission electron microscope by nanoparticle labels
Authors: Zhang Lei , He Longbing , Yang Yufeng , Hong Hua , Tang Luping , Sun Litao 
Published: April 2021

AbstractBeam‐induced heating effect on nanoscale samples is a crucial question, as it strongly influences the interpretation of observed unusual behaviours. This question is currently under debate without a convincing conclusion. Here, using silver nitride (Ag3N) nanoparticles as temperature labels, we perform an investigation on this heating effect inside a transmission electron microscope (TEM) under normal imaging conditions. Combined with experimental measurements and semi‐quantitative calculations, a temperature increase of more than 100 K is estimated and confirmed in the graphite carbon nitride (g‐C3N4) films. Strong temperature gradients are found to exist in the single‐end fixed g‐C3N4 films. The influencing factors of heat accumulation are also investigated and discussed. Findings in this study may shed some light on the understanding of the abnormal behaviours of nano‐objects observed inside TEM.
Facile and simple synthesis of silver‐doped hydroxyapatite porous microspheres with good sphericity
Authors: Mei Fengce , Yao Shengkun , Xu Wei‐li , Wu Yanling , Wang Yanmin , Qi Mei‐li 
Published: April 2021

AbstractSilver‐doped hydroxyapatite (Ag‐HA) porous microspheres were synthesized by one‐step hydrothermal route at 180 °C for 10 h in the presence of l‐glutamic acid (Glu) as a growth regulator. The effects of Glu concentration and silver ion doping on the phase and morphology of the products were thoroughly characterized by X‐ray diffraction and scanning electron microscopy. Results show that the presence of Glu induces the growth of hydroxyapatite crystals from flower‐like aggregates to porous microspheres, and the addition of silver ions can maintain the roundness of hydroxyapatite microspheres. The Brunauer–Emmett–Teller analysis, particle dispersity and antibacterial property were also conducted. The optimal parameters for porous silver‐doped hydroxyapatite microspheres with uniform morphology was obtained with the atomic molar ratio n(Ag)/n[Ag + Ca] = 0.01 and Glu concentration at 0.06 M.
Non‐local effect on the frequency analysis of chiral single‐walled carbon nanotubes using wave propagation approach
Authors: Hussain Muzamal , Khadimallah Mohamed A. , Naeem Muhammad Nawaz 
Published: April 2021

AbstractIn the current study, the non‐local elasticity theory is utilized for the vibration analysis of single‐walled carbon nanotubes (SWCNTs). Frequency spectra have been demonstrated for different non‐local parameters and bending rigidity for three sort of SWCNTs. It has been investigated that, by increasing the non‐local parameter, frequencies decreases. The frequencies increase on increasing the aspect ratio. Throughout, the computation frequencies of clamped–free are lower than that of clamped–clamped. On increasing the bending rigidity, frequencies of chiral SWCNTs increase. Subsequently, the validation study has been performed through the available published literature. To discretize the governing equations of these models into frequency equations of SWCNTs, wave propagation approach is used. The complex exponential form with the number of axial modes depends on the boundary conditions indicated at the edges of the carbon nanotubes.
Hydrangea‐like ZnS/ZnIn2S4 microspheres with outstanding photocatalytic degradation of xylenol orange and thymol blue under vis irradiation
Authors: Fa Dejuan , Miao Yuqing 
Published: April 2021

AbstractBy hydrothermal reaction, the hydrangea‐like ZnS/ZnIn2S4 microspheres were prepared in the presence of thioacetamide. X‐ray photoelectron spectroscopy and high resolution transmission electron microscopy confirmed that the ultra‐long nanowires are composed of ZnS and ZnIn2S4. Scanning electron microscopy showed the morphology of ultra‐thin nanosheets with an average thickness of 8.5 nm cross from inside to outside, forming ZnS/ZnIn2S4 microspheres with a porous diameter of about 2.8 μm. Nitrogen adsorption desorption isotherm determined that the BET specific surface area of the microspheres was 109.19 m2/g which showed that they have a large specific surface area. The obtained ZnS/ZnIn2S4 microspheres showed broad absorbance ranging from UV (200 nm) to visible (520 nm) with low indirect band gaps of 2.08 eV. It leads to outstanding visible‐light‐driven photocatalysis for the degradation of xylenol orange (XO) and thymol blue (TB) in water, and the two dyes were almost completely degraded after 60 and 135 min, respectively. This provides new potential to explore nanomaterials for efficient photo‐driven degradation of organic dyes under visible light irradiation.
A graphical approach for controller design with desired stability margins for a DC–DC boost converter
Authors: Kalim Md. Imran , Ali Ahmad 
Published: April 2021

AbstractA novel graphical tuning method of PID controller for output voltage regulation of a DC–DC boost converter is proposed. The advantage of the presented method is that the desired robustness level in terms of gain and phase margins can be pre‐specified. A technique to limit the noise level in the control signal to a pre‐specified value by selecting the derivative gain (), is also discussed. Simplicity of the technique is an added advantage. Concept of root crossing boundaries along with the gain phase margin tester is applied to compute constant gain and phase margin boundaries in the controller parameters plane. The overlapping area of constant gain and phase margin boundaries within the all stability region is the desired gain and phase margin region (DGPMR). Controller parameters are obtained by computing the centroid of the triangular convex region of the DGPMR. Effectiveness of the proposed tuning strategy is illustrated by simulation and hardware experimental results. Furthermore, the proposed method yields improved closed‐loop performance compared to a recently reported tuning strategy in nominal as well as perturbed scenarios.
A novel common‐ground switched‐capacitor five‐level inverter with adaptive hysteresis current control for grid‐connected applications
Authors: Barzegarkhoo Reza , Mojallali Hamed , Shahalami Seyed Hamid , Siwakoti Yam P. 
Published: April 2021

AbstractThe aim of this paper is to present a new topology of single‐phase transformerless inverters, which can be tied to the local grid as a low‐scaled ac module system. The proposed topology offers a common ground between the neutral point of the ac grid and the negative terminal of the dc supply, and can properly alleviate the concern of variable common mode voltage and leakage current problems. This promising feature is acquired by the aim of both the switched‐capacitor and charge pumped circuit cells. In order to inject a tightly controlled ac current to the grid, an adaptive hysteresis current controller scheme is also presented, which can guarantee almost fixed switching frequency operation of the involved power switches. A complete theoretical analysis, comparative study, and the relevant experimental results are also given to confirm the superior performance of the proposed topology.
An energy balancing strategy for modular multilevel converter based grid‐connected photovoltaic systems
Authors: Elsanabary Ahmed , Mekhilef Saad , Seyedmahmoudian Mehdi , Stojcevski Alex 
Published: April 2021

AbstractModular multilevel converters (MMC)s are promising candidates for large‐scale grid‐connected photovoltaic (PV) systems. Due to their modular structure, MMCs provide a direct connection of the PV arrays to the converter submodules. They also offer scalability, independent maximum power point tracking, and enhanced power quality with internal power flow capabilities. However, the intermittent nature of PV arrays introduces a power unbalance inside the converter, which affects its operation. This paper addresses the issue and proposes an energy balancing strategy for the grid‐connected MMC‐based PV system. It uses the internally generated leg currents to control the power flow inside the converter and inject a three‐phase balanced current to the grid with low total harmonic distortion. Compared to the existing strategies, the proposed strategy can overcome any condition of the power unbalance with minimal submodule voltage fluctuations. A 162‐kW, 9‐kV PV grid‐connected system is modelled and simulated in MATLAB Simulink environment. The corresponding results are presented to demonstrate the effectiveness of the proposed control strategy for grid‐connected PV systems.
Multi‐functional commercial solar photovoltaic plant integrated to three‐phase low voltage AC network
Authors: Modi Gaurav , Singh Bhim 
Published: April 2021

AbstractThis study presents the commercial solar PV plant (SPVP) operation, integrated into the low voltage (LV) AC network. The SPVP has the multi‐functional operational capability. It feeds the PV array generated power to loads and the AC network, while ensuring the power quality improvement at the point of common coupling (PCC) as per the IEEE std. 519, irrespective of the load characteristic (linear/nonlinear and balanced/unbalanced). The SPVP minimises the line losses in the AC network by recouping the load reactive power requirement locally. Moreover, the SPVP operates in either maximum power extraction (MPE) mode or constant power generation (CPG) mode, depending upon the rise in PCC voltage amplitude during the peak PV array power generation and low load demand condition. The SPVP switches between the MPE and the CPG modes during the high rise in PCC voltage amplitude and regulates the PV array generated power to protect itself and the load connected at PCC. In this study, an adaptive filter technique based on maximum correntropy criterion is used for the PQI, and the perturb and observe based algorithm is used for MPE. A simulation model and reduced rating hardware prototype are developed to validate the system's performance.
Co‐optimisation and settlement of power‐gas coupled system in day‐ahead market under multiple uncertainties
Authors: Zheng Xiaodong , Xu Yan , Li Zhengmao , Chen Haoyong 
Published: April 2021

AbstractThe interdependency of power systems and natural gas systems is being reinforced by the emerging power‐to‐gas facilities (PtGs), and the existing gas‐fired generators. To jointly improve the efficiency and security under diverse uncertainties from renewable energy resources and load demands, it is essential to co‐optimise these two energy systems for day‐ahead market clearance. A data‐driven integrated electricity‐gas system stochastic co‐optimisation model is proposed in tis work. The model is accurately approximated by sequential mixed integer second‐order cone programming, which can then be solved in parallel and decentralised manners by leveraging generalised Benders decomposition. Since the price formation and settlement issues have rarely been investigated for integrated electricity–gas systems in an uncertainty setting, a novel concept of expected locational marginal value is proposed to credit the flexibility of PtGs that helps hedging uncertainties. By comparing with a deterministic model and a distributionally robust model, the advantage of the proposed stochastic model and the efficiency of the proposed solution method are validated. Detailed results of pricing and settlement for PtGs are presented, showing that the expected locational marginal value can fairly credit the contribution of PtGs and reflect the system deficiency of capturing uncertainties.
Analytical solution of stochastic real‐time dispatch incorporating wind power uncertainty characterized by Cauchy distribution
Authors: Xu Shuwei , Wu Wenchuan , Yang Yue , Wang Bin , Wang Xiaohai 
Published: April 2021

AbstractReal‐time power dispatch can coordinate wind farms, automatic generation control units and non‐automatic generation control units. In real‐time power dispatch, the probable wind power forecast errors should be appropriately formulated to ensure system security with high probability and minimize operational cost. Previous studies and the authors' onsite tests show that Cauchy distribution effectively fits the “leptokurtic” feature of small‐timescale wind power forecast errors distributions. In this paper, a chance‐constrained real‐time dispatch model with the wind power forecast errors represented by multivariate Cauchy distribution is proposed. Since the Cauchy distribution is stable and has promising mathematical characteristics, the proposed chance‐constrained real‐time dispatch model can be analytically transformed to a convex optimization problem considering the dependence among wind farms’ outputs. Moreover, the proposed model incorporates an affine control strategy compatible with automatic generation control systems. This strategy makes the chance‐constrained real‐time dispatch adaptively take into account both the potential power ramping requirement and power variation on transmission lines caused by the generation adjustment to offset the wind power forecast errors in real‐time power dispatch stage. Numerical test results show that the proposed method is reliable and effective. Meanwhile it is very efficient and suitable for real‐time application.
Microgrid protection against high impedance faults with robustness to harmonic intrusion and weather intermittency
Authors: Manohar Murli , Koley Ebha , Ghosh Subhojit 
Published: April 2021

AbstractThe high impedance faults (HIF) in microgrids are characterized by low magnitude fault current with inherent non‐linearity and random behavior. The possible weather intermittency in PV integrated microgrids and the intrusion of harmonics due to power converters and non‐linear loading, further reduce the fault current during HIF. The insignificant fault current does not allow detection of HIF by conventional overcurrent relays. In this regard, a reliable and robust protection scheme based on the combined framework of probabilistic modelling, least square and Adaline algorithm, sine cosine algorithm (SCA) and support vector machine (SVM), has been proposed to perform the tasks of mode detection, fault detection/classification and section identification during HIF in microgrid. The algorithm involves online extraction of harmonic components and stochastic modelling of intermittency in solar irradiance. The performance of the proposed scheme has been analysed in terms of robustness against harmonics intrusion and weather intermittency during HIF. The performance comparison of the proposed scheme with the decision tree (DT) and classical SVM based techniques reflects its effectiveness with improved immunity against harmonic intrusion and weather intermittency. Further, the proposed scheme has been validated using OPAL‐RT digital simulator for evaluating its appropriateness in real‐time settings.