bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling human liver microphysiology on a chip through a finite element based design approach
Authors: Menezes Pedro Duarte , Gadegaard Nikolaj , Natal Jorge Renato M. , Pinto Sónia I. S. 
Published: February 2021

AbstractOrgan‐on‐a‐chip (OoaC) are microfluidic devices capable of growing living tissue and replicate the intricate microenvironments of human organs in vitro, being heralded as having the potential to revolutionize biological research and healthcare by providing unprecedented control over fluid flow, relevant tissue to volume ratio, compatibility with high‐resolution content screening and a reduced footprint. Finite element modelling is proven to be an efficient approach to simulate the microenvironments of OoaC devices, and may be used to study the existing correlations between geometry and hydrodynamics, towards developing devices of greater accuracy. The present work aims to refine a steady‐state gradient generator for the development of a more relevant human liver model. For this purpose, the finite element method was used to simulate the device and predict which design settings, expressed by individual parameters, would better replicate in vitro the oxygen gradients found in vivo within the human liver acinus. To verify the model's predictive capabilities, two distinct examples were replicated from literature. Finite element analysis enabled obtaining an ideal solution, designated as liver gradient‐on‐a‐chip, characterised by a novel way to control gradient generation, from which it was possible to determine concentration values ranging between3%and12%, thus providing a precise correlation with in vivo oxygen zonation, comprised between 3%–5% and 10%–12% within respectively the perivenous and periportal zones of the human liver acinus. Shear stress was also determined to average the value of0.037Pa, and therefore meet the interval determined from literature to enhance liver tissue culture, comprised between0.01 − 0.05Pa.
Investigation of the performances of advanced image classification‐based ground filtering approaches for digital terrain model generation
Authors: Yilmaz Volkan 
Published: February 2021

AbstractThe majority of the ground filtering techniques proposed so far use several user‐defined parameter values. Since no standard protocols exist to define these parameters, obtaining the optimum filtering performance is very hard, especially in large‐extent areas with abrupt topography changes. This, of course, reveals the necessity of some more efficient strategies to ease the ground filtering process in such areas. Utilizing classified images for ground filtering purpose may be of help to achieve this. Hence, this study, for the first time in the literature, investigated the performances of the state‐of‐the‐art machine learning algorithms maximum likelihood (ML), artificial neural network (ANN), support vector machines (SVM), and random forest (RF) in ground filtering of a UAS‐based point cloud. The used approaches were based on the assignment of the points corresponding to the ground‐related classes to the ground class. Evaluations showed that the SVM‐based ground filtering approach achieved the optimum filtering result. The SVM‐, ML‐, RF‐, and ANN‐based ground filtering methods achieved the total errors of 13.2%, 16.4%, 19.6%, and 21.9% in the test site, respectively.
Anion Transmembrane Nanochannels from Pore‐Forming Helices Constructed by the Dynamic Covalent Reaction of Dihydrazide and Dialdehyde Units
Authors: Zhang Chenyang , Zhang Jing , Li Wencan , Mao Shizhong , Dong Zeyuan 
Published: February 2021

AbstractAnion transmembrane nanochannels constructed from dynamic covalent helices (DCHs) are reported. The dynamic covalent structures can be synthesized by one‐pot dynamic covalent reactions and helically self‐fold into nanotubes through intramolecular hydrogen bonding and π‐π interactions. Such helical structures can vertically self‐assemble into long nanofibers under π‐π stacking and their hollow nanocavities finally form ion permeation pathways across the lipid membranes. Single‐channel electrophysiology signals provide solid evidence of DCHs following the channel rather than the carrier mechanism. Owing to the pore‐forming capacity of DCHs, nanochannels are able to accelerate the movement of anions across lipid membranes with high transport activity (EC50=0.08 mol %). Moreover, DCH channels show dehydration energy dependent anion selectivity. This report highlights the importance of such DCHs as general channel scaffolds with economical synthesis and special nanocavities.
Physiologically‐Based Pharmacokinetic Modeling Combined with Swiss HIV Cohort Study Data Supports No Dose Adjustment of Bictegravir in Elderly Individuals Living With HIV
Authors: Stader Felix , Courlet Perrine , Decosterd Laurent A. , Battegay Manuel , Marzolini Catia 
Published: February 2021

Clinical studies in aging people living with HIV (PLWH) are sparse for the novel integrase inhibitor bictegravir, leading to some uncertainty about dosing recommendations for elderly PLWH. The objective of this study was to investigate the continuous impact of aging on bictegravir pharmacokinetics by combining clinically observed data with modeling to support a safe and efficient anti‐HIV therapy with advanced age. A physiologically‐based pharmacokinetic (PBPK) model was developed for bictegravir with clinically observed data from phase I studies. The predictive model performance was verified using bictegravir plasma concentrations sampled as part of the general therapeutic drug monitoring (TDM) program of the Swiss HIV Cohort Study in young (20–55 years) and elderly PLWH (55–85 years). The verified PBPK model subsequently predicted the continuous impact of aging on bictegravir pharmacokinetics across adulthood (20–99 years). Bictegravir exposure was unchanged in elderly compared with young PLWH when analyzing the TDM data of the Swiss HIV Cohort Study. PBPK simulations predicted clinically observed data from 60 young and 32 elderly PLWH mostly within the 95% confidence interval, demonstrating the predictive power of the used modeling approach. Simulations predicted drug exposure to increase up to 40% during adulthood, which was not statistically significantly different from the age‐related pharmacokinetic changes of other HIV and non‐HIV drugs. Sex had no impact on the age‐related changes of bictegravir pharmacokinetics. Considering the safety margin of bictegravir, a dose adjustment for the novel integrase inhibitor isa priorinot necessary in elderly PLWH in the absence of severe comorbidities.
Preparation of an In2S3/TiO2 Heterostructure for Enhanced Activity in Carbon Dioxide Photocatalytic Reduction
Authors: Huang Guofang , Shen Qiuyue , Ma Xiaoyu , Zhong Junbo , Chen Jiufu , Huang Jingwei , Wang Lei , She Houde , Wang Qizhao 
Published: February 2021

AbstractConstructing a heterojunction structure is considered to be a promising strategy for the photocatalytic reduction of carbon dioxide. Herein, In2S3/TiO2 composite materials were successfully prepared by a hydrothermal method and were used for the construction of a typical type II heterojunction. Through optimizing the In2S3/TiO2 ratio, a high separation efficiency of the photogenerated electron‐hole pairs has been achieved. Therefore, 5 % In2S3/TiO2 showed a CH4 production rate of 16.21 μmol g−1 h−1 without using additional sacrificial agent, and the catalytic activity far exceeds that of pure TiO2 nanosheets. The high catalytic activity of the hybrid catalyst can be ascribed to the high specific surface area, enhanced visible light harvesting ability and improved electron transport capability. In addition, based on the XPS valence band spectrum, UV/Vis DRS and photoelectrochemical characteristics, a possible mechanism for the reduction of CO2 by 5 % In2S3/TiO2 photocatalyst is proposed.
Optimization and parametric analysis of slotted microstrip antenna using particle swarm optimization and curve fitting
Authors: Verma Ramesh Kumar , Srivastava Dinesh Kumar 
Published: February 2021

SummaryThis article presents an optimization and analysis of open‐ended “+” shape slotted microstrip antenna utilizing curve fitting‐based particle swarm optimization (PSO) for bandwidth (BW) enhancement and resonant frequency (FR) stabilization at 2.40 GHz design frequency. The optimized antenna BW is obtained 48.68% (1155 MHz) resonating at 2.391 GHz compared to 37.01% (867 MHz) BW of nonoptimized antenna resonating at 2.481 GHz and 13.29% (312 MHz) BW of conventional antenna resonating at 2.353 GHz. The optimization is performed using MATLAB‐based PSO program with relationship equations generated by curve fitting software (Graphmatica) for BW and FR. The data for BW and FR is obtained by varying some selected parameters of open‐ended “+” shape slotted (nonoptimized) patch antenna using IE3D tool. Finally, the performance of optimized antenna is compared with nonoptimized open‐ended “+” shape slotted antenna and conventional antenna. A good agreement is observed between simulated and measured results. The resonating band 1.795 to 2.950 GHz of proposed antenna is suitable for WiMAX (2.3 GHz), WLAN (2.4 GHz), and other applications in partial L and S bands.
Pattern of circulating SARS‐CoV‐2‐specific antibody‐secreting and memory B‐cell generation in patients with acute COVID‐19
Authors: Byazrova Maria , Yusubalieva Gaukhar , Spiridonova Anna , Efimov Grigory , Mazurov Dmitriy , Baranov Konstantin , Baklaushev Vladimir , Filatov Alexander 
Published: February 2021

AbstractObjectivesTo predict the spread of coronavirus disease (COVID‐19), information regarding the immunological memory for disease‐specific antigens is necessary. The possibility of reinfection, as well as the efficacy of vaccines for COVID‐19 that are currently under development, will largely depend on the quality and longevity of immunological memory in patients. To elucidate the process of humoral immunity development, we analysed the generation of plasmablasts and virus receptor‐binding domain (RBD)‐specific memory B (Bmem) cells in patients during the acute phase of COVID‐19.MethodsThe frequencies of RBD‐binding plasmablasts and RBD‐specific antibody‐secreting cells (ASCs) in the peripheral blood samples collected from patients with COVID‐19 were measured using flow cytometry and the ELISpot assay.ResultsThe acute phase of COVID‐19 was characterised by the transient appearance of total as well as RBD‐binding plasmablasts. ELISpot analysis indicated that most patients exhibited a spontaneous secretion of RBD‐specific ASCs in the circulation with good correlation between the IgG and IgM subsets. IL‐21/CD40L stimulation of purified B cells induced the activation and proliferation of Bmem cells, which led to the generation of plasmablast phenotypic cells as well as RBD‐specific ASCs. No correlation was observed between the frequency of Bmem cell‐derived and spontaneous ASCs, suggesting that the two types of ASCs were weakly associated with each other.ConclusionOur findings reveal that SARS‐CoV‐2‐specific Bmem cells are generated during the acute phase of COVID‐19. These findings can serve as a basis for further studies on the longevity of SARS‐CoV‐2‐specific B‐cell memory.
Sustained cellular immunity in adults recovered from mild COVID‐19
Authors: Rank Andreas , Löhr Phillip , Hoffmann Reinhard , Ebigbo Alanna , Grützner Stefanie , Schmid Christoph , Claus Rainer 
Published: February 2021

AbstractTransient lymphocytopenia is frequently observed in acute phase of coronavirus disease 2019 (COVID‐19). It remains a concern whether impairment of cellular immunity may be retained after COVID‐19. Here, we demonstrate by extensive lymphocyte profiling in 44 adults after mild COVID‐19 that cellular immunity is not fundamentally altered in convalescent patients. Except for increased activated CD8+ lymphocytes, total counts of B, T, and NK cells and their subsets did not differ significantly between patients after COVID‐19 and healthy controls after a median of 27 days (range 13–45) suggesting no residual cellular immune deficiency after recovery from mild COVID‐19.
Enhancement of image transmission using chaotic interleaving with discrete wavelet transform‐based single‐carrier frequency division multiple access system
Authors: Mehallel Elhadi , Abed Djamel , Boukaache Abdenour , Bouchemel Ammar 
Published: February 2021

SummaryLong‐term evolution (LTE) system adopts single‐carrier frequency division multiple access (SC‐FDMA) technique for high data‐rate uplink wireless communication mainly due to its advantage of high power efficiency and low peak‐to‐average‐power ratio (PAPR). This paper presents a chaotic interleaving scheme for the discrete wavelet transform‐based SC‐FDMA (DWT SC‐FDMA) system to improve the transmission quality of images. This interleaving process is‐ based on applying the chaotic Baker map to the image before transmission. The proposed scheme combines the advantages of excellent orthogonality and spectral containment from DWT SC‐FDMA and performances enhancement from chaotic interleaving. The performances evaluation of the DWT‐SC‐FDMA system with the chaotic interleaving scheme for efficient image transmission is studied and compared with two schemes of SC‐FDMA‐based systems: discrete Fourier transform SC‐FDMA (DFT SC‐FDMA) and discrete cosine transform SC‐FDMA (DCT SC‐FDMA) over different wireless channel and subcarriers mapping modes. This comparison aims to select the most suitable structure of SC‐FDMA for the efficient transmission of the images.The obtained results demonstrate the efficiency of the proposed scheme, which gives an improvement of peak signal‐to‐noise ratio (PSNR) of about 36 dB (at SNR = 8 dB) is the case of SUI‐3 channel and a significant enhancement in bit‐error‐ratio (BER) performance.
Understanding 3D structural complexity of individual Scots pine trees with different management history
Authors: Saarinen Ninni , Calders Kim , Kankare Ville , Yrttimaa Tuomas , Junttila Samuli , Luoma Ville , Huuskonen Saija , Hynynen Jari , Verbeeck Hans 
Published: February 2021

AbstractTree functional traits together with processes such as forest regeneration, growth, and mortality affect forest and tree structure. Forest management inherently impacts these processes. Moreover, forest structure, biodiversity, resilience, and carbon uptake can be sustained and enhanced with forest management activities. To assess structural complexity of individual trees, comprehensive and quantitative measures are needed, and they are often lacking for current forest management practices. Here, we utilized 3D information from individual Scots pine (Pinus sylvestrisL.) trees obtained with terrestrial laser scanning to, first, assess effects of forest management on structural complexity of individual trees and, second, understand relationship between several tree attributes and structural complexity. We studied structural complexity of individual trees represented by a single scale‐independent metric called “box dimension.” This study aimed at identifying drivers affecting structural complexity of individual Scots pine trees in boreal forest conditions. The results showed that thinning increased structural complexity of individual Scots pine trees. Furthermore, we found a relationship between structural complexity and stem and crown size and shape as well as tree growth. Thus, it can be concluded that forest management affected structural complexity of individual Scots pine trees in managed boreal forests, and stem, crown, and growth attributes were identified as drivers of it.
Which factors contribute most to genome size variation within angiosperms?
Authors: Wang Dandan , Zheng Zeyu , Li Ying , Hu Hongyin , Wang Zhenyue , Du Xin , Zhang Shangzhe , Zhu Mingjia , Dong Longwei , Ren Guangpeng , Yang Yongzhi 
Published: February 2021

AbstractGenome size varies greatly across the flowering plants and has played an important role in shaping their evolution. It has been reported that many factors correlate with the variation in genome size, but few studies have systematically explored this at the genomic level. Here, we scan genomic information for 74 species from 74 families in 38 orders covering the major groups of angiosperms (the taxonomic information was acquired from the latest Angiosperm Phylogeny Group (APG IV) system) to evaluate the correlation between genome size variation and different genome characteristics: polyploidization, different types of repeat sequence content, and the dynamics of long terminal repeat retrotransposons (LTRs). Surprisingly, we found that polyploidization shows no significant correlation with genome size, while LTR content demonstrates a significantly positive correlation. This may be due to genome instability after polyploidization, and since LTRs occupy most of the genome content, it may directly result in most of the genome variation. We found that the LTR insertion time is significantly negatively correlated with genome size, which may reflect the competition between insertion and deletion of LTRs in each genome, and that the old insertions are usually easy to recognize and eliminate. We also noticed that most of the LTR burst occurred within the last 3 million years, a timeframe consistent with the violent climate fluctuations in the Pleistocene. Our findings enhance our understanding of genome size evolution within angiosperms, and our methods offer immediate implications for corresponding research in other datasets.
Activation of Molecular Hydrogen by Inter‐ and Intramolecular Al−N Lewis Pairs
Authors: Bodach Alexander , Nöthling Nils , Felderhoff Michael 
Published: February 2021

AbstractThe field of frustrated Lewis pair chemistry offers many opportunities to activate molecular hydrogen, but Al−N systems have not been established yet. In this work, we describe several intermolecular classical Al−N Lewis pairs and an intramolecular ortho‐ala‐aminoarene for the activation of molecular hydrogen. Their ability was investigated using the isotope exchange reaction from HD to H2 and D2. The herein studied intermolecular Lewis pairs were based on alkylalanes and N‐methyldiphenylamine, while the intramolecular Lewis pair was (o‐TMP−C6H4)AlH2 ((2‐(2,2,6,6‐tetramethyl‐piperidin‐1‐yl)phenyl)‐aluminium dihydride). The activation of molecular hydrogen was carried out in toluene under mild conditions and monitored by 1H and 2H NMR spectroscopy. Furthermore, the Al−N interaction has been probed by 27Al NMR and crystallographic studies. Additionally, the crystal structure of pure AliBu3 was determined. These studies may attribute the pronounced reactivities of these Al−N compounds to elongated Al−N bond lengths.
Properties of graphite blocks consisting of ordered graphite flakes with bimodal particle size distribution
Authors: Lee Moon H. , Kim Byung C. , Kim Ho Y. , Jeong Euigyung , Jeong Sooyeon , Park Kwang S. , Han Joong T. , Woo Jong S. 
Published: February 2021

AbstractPetroleum pitch‐based graphite blocks (GBs) attract considerable attention owing to their low cost, high yield, and possible application as heat sink components. However, no studies have systematically investigated the particle size distribution of GBs, their structures, and the relationship between the structures and thermal properties resulting from graphitization. Hence, herein, we present a novel method for fabricating petroleum pitch‐based GBs using natural graphite flakes (GFs) of sizes ranging between 50 and 500 μm and a bimodal particle size distribution. Furthermore, the effects of the mean GF particle size, pitch binder content, and microstructure of the GBs with low GF contents on compression molding with elevated hot‐pressing temperatures after graphitization are investigated. To investigate the effect of packing density with a GF size of 500 μm, we mix a small‐sized GF (50 μm) and low pitch binder content by kneading. In particular, specimens in the in‐plane direction with a bimodal particle size distribution of GFs and 10 wt% pitch binder yield optimum density and thermal conductivity values of 1.74 g m−3 and 384 Wm−1 K−1, respectively, after high‐temperature graphitization at 2600°C. These findings provide insights for developing high‐performance GBs for use in heat sink components with high thermal conductivity.
Polymer‐assisted fully recyclable flexible sensors
Authors: Tao Xinglei , Liao Shenglong , Wang Yapei 
Published: February 2021

AbstractThe increasing number of electronic sensors after their disposal is leading to severe environmental threatens due to the release of heavy metals or other nonrecyclable semiconductors in sensing units and have raised worldwide interest in the design of electronic sensors with longer‐term service life in order to reduce the discharge of electrical pollutants. From this point of view, there have been a great number of examples relevant to electronic sensors with self‐healing or recyclable properties. Unlike the enormous studies paid to self‐healing electronic sensors, a limited number of fully recyclable sensors have been exploited and there is no review article relevant to this topic so far. This minireview aims to summarize the recent progresses of electronic sensors that could be shredded and reshaped with the assistance of recyclable polymers. Two types of fully recyclable electronic sensors are mainly focused, including blended type via blending sensing conductors in the polymer matrix and intrinsic type composed of sensing polymers. According to their classification, we specifically demonstrate the basic design principle, recycling procedure, and sensing performance of those different types of recyclable electronic sensors. At last, a brief discussion regarding the remaining challenges and future perspectives of this new research area is delivered which hopefully provides inspirations to develop more fully recyclable electronic sensors with versatile functions.image
The prudential role of Basel III liquidity provisions towards financial stability
Authors: Papadamou Stephanos , Sogiakas Dimitrios , Sogiakas Vasilios , Toudas Kanellos 
Published: February 2021

AbstractThis paper examines the prudential role and the effectiveness of banking regulation in EU. Using a unique sample of banks' balance and off‐balance sheet data, we focus on the capital requirements (tier1) and the liquidity characteristics of the banking sector. The latter factor is accounted for by the Basel III net stable funding ratio (NSFR) that was launched on 2010 with effect on 2018 and refers to the long‐term liquidity provision of banks. By adopting a dynamic panel‐vector autoregression (VAR) analysis, we have found strong evidence in favor to the forecasting and prudential supervision role of NSFR, which provides the means for improving banks' performance and for promoting the stability in the banking sector. On the other hand, capital requirements (tier1) incorporate a responsive component to uncertainty in the financial system. Finally, our findings support the prudential role of Basel III liquidity provisions, which can play the role of leading indicators of financial stability of financial markets and specifically of the financial sector.