bluuebunny/crossref_metadata_2025 huggingface dataset:
A prospective STudy using invAsive haemodynamic measurements foLLowing catheter ablation for AF and early HFpEF: STALL AF‐HFpEF
Authors: Sugumar Hariharan , Nanayakkara Shane , Vizi Donna , Wright Leah , Chieng David , Leet Angeline , Mariani Justin A. , Voskoboinik Aleksandr , Prabhu Sandeep , Taylor Andrew J. , Kalman Jonathan M. , Kistler Peter M. , Kaye David M. , Ling Liang‐Han
Published: February 2021

Aims

The impact of atrial fibrillation (AF) ablation in early heart failure with preserved ejection fraction (HFpEF) is unknown. Our aim was to determine the impact of AF ablation on symptoms and exercise haemodynamic parameters of early HFpEF.

Methods and results

Symptomatic AF patients referred for index AF ablation with ejection fraction ≥50% underwent baseline quality of life questionnaires, echocardiography, cardiac magnetic resonance imaging, exercise right heart catheterisation (exRHC), and brain natriuretic peptide (BNP) testing. HFpEF was defined by resting pulmonary capillary wedge pressure (PCWP) ≥15 mmHg or peak exercise PCWP ≥25 mmHg. Patients with HFpEF were offered AF ablation and follow‐up exRHC ≥6 months post‐ablation. Of 54 patients undergoing baseline evaluation, 35 (65%) had HFpEF identified by exRHC. HFpEF patients were older (64 ± 10 vs. 54 ± 13 years, P < 0.01), and more frequently female (54% vs. 16%, P < 0.01), hypertensive (63% vs. 16%, P < 0.001), and suffering persistent AF (66% vs. 11%, P < 0.001), compared to those without HFpEF. Twenty HFpEF patients underwent AF ablation and follow‐up exRHC 12 ± 6 months post‐ablation. Nine (45%) patients no longer fulfilled exRHC criteria for HFpEF at follow‐up. Patients remaining arrhythmia free (n = 9, 45%) showed significant improvements in peak exercise PCWP (29 ± 4 to 23 ± 2 mmHg, P < 0.01) and Minnesota Living with Heart Failure (MLHF) score (55 ± 30 to 22 ± 30, P < 0.01) while the remainder did not (PCWP 31 ± 5 to 30.0 ± 4 mmHg, P = NS; MLHF score 55 ± 23 to 25 ± 20, P = NS).

Conclusion

Heart failure with preserved ejection fraction frequently coexists in patients with symptomatic AF and preserved ejection fraction. Restoration and maintenance of sinus rhythm in patients with comorbid AF and HFpEF improves haemodynamic parameters, BNP and symptoms associated with HFpEF.
Multiomics uncovers developing immunological lineages in human
Authors: Stephenson Emily , Webb Simone , Haniffa Muzlifah
Published: February 2021

The development of the human immune system during embryonic and fetal life has historically been difficult to research due to limited access to human tissue. Experimental animal models have been widely used to study development but cellular and molecular programmes may not be conserved across species. The advent of multiomic single‐cell technologies and an increase in human developmental tissue biobank resources have facilitated single‐cell multiomic studies focused on human immune development. A critical question in the near future is "How do we best reconcile scientific findings across multiple omic modalities, developmental time, and organismic space?" In this review, we discuss the application of single‐cell multiomic technologies to unravel the major cellular lineages in the prenatal human immune system. We also identify key areas where the combined power of multiomics technologies can be leveraged to address specific immunological gaps in our current knowledge and explore new research horizons in human development.
Oxidative Rearrangement of 2‐(2‐Aminobenzyl)furans: Synthesis of Functionalized Indoles and Carbazoles
Authors: Merkushev Anton A. , Makarov Anton S. , Shpuntov Pavel M. , Abaev Vladimir T. , Trushkov Igor V. , Uchuskin Maxim G.
Published: February 2021

2‐(2‐Acylvinyl)indoles obtained by oxidative rearrangement of substituted 2‐(2‐aminobenzyl)furans could be used to construct structural analogues of antifungal alkaloids caulindoles A−D as well as other indole‐derived molecules and substituted carbazoles by introducing new reaction centers into the structure of starting materials or by synthetic manipulation with functional groups of the obtained compounds.
Excited‐State 2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ*) Initiated Organic Synthetic Transformations under Visible‐Light Irradiation
Authors: Natarajan Palani , König Burkhard
Published: February 2021

The one‐electron oxidizing capacity of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) improves significantly by visible‐light excitation. The exited‐state DDQ (DDQ*) even converts benzene, fluoroarenes, heteroarenes, benzyls, and olefins into their corresponding radical cations as well as chloride and other anions into their radicals. These reactive intermediates have been utilized for the generation of C−C and C−X (N, O, or Cl) bonds in the synthesis of valuable organic compounds and natural products. This mini review provides an overview of such DDQ*‐initiated organic transformations with their scope and limitations and discusses the proposed reactions mechanisms.
Reduction in sample injection bias using pressure gradients generated on chip
Authors: Liu Yukari , Xia Ling , Dutta Debashis
Published: February 2021

Sample injection in microchip‐based capillary zone electrophoresis (CZE) frequently rely on the use of electric fields which can introduce differences in the injected volume for the various analytes depending on their electrophoretic mobilities and molecular diffusivities. While such injection biases may be minimized by employing hydrodynamic flows during the injection process, this approach typically requires excellent dynamic control over the pressure gradients applied within a microfluidic network. The current article describes a microchip device that offers this needed control by generating pressure gradients on‐chip via electrokinetic means to minimize the dead volume in the system. In order to realize the desired pressure‐generation capability, an electric field was applied across two channel segments of different depths to produce a mismatch in the electroosmotic flow rate at their junction. The resulting pressure‐driven flow was then utilized to introduce sample zones into a CZE channel with minimal injection bias. The reported injection strategy allowed the introduction of narrow sample plugs with spatial standard deviations down to about 45 μm. This injection technique was later integrated to a capillary zone electrophoresis process for analyzing amino acid samples yielding separation resolutions of about 4–6 for the analyte peaks in a 3 cm long analysis channel.
Detection of cell‐free fetal DNA in maternal plasma using two types of compound markers
Authors: Tan Yu , Zhang Lin , Bai Peng , Li Zhilong , Zhang RanRan , Yang Fan , Wang Li , Liang Weibo
Published: February 2021

With the discovery of circulating cell‐free fetal DNA (cffDNA) in maternal plasma, noninvasive prenatal testing became possible. However, analysis of low‐level cffDNA against high background maternal DNA remains complicated and challenging. To circumvent this limitation, selective amplification of cffDNA was used in this study. Two kinds of compound markers (namely DIP‐STR and SNP‐STR), both based on selective amplification, were used here for targeting fetal DNA. By designing two allele‐specific forward primers for DIP‐STR and SNP‐STR, DNA fragments with different DIP/SNP alleles can be selectively amplified. When analyzing maternal plasma DNA, these markers can selectively target paternally inherited fetal alleles whose DIP/SNP allele was not shared with the mother. In this study, 21 families were studied with six DIP‐STRs and 11 SNP‐STRs. Fetal DNA was successfully detected across plasma samples for at least one marker. Detection rate varied between DIP‐STR and SNP‐STR markers, and DIP‐STR outperforms SNP‐STR. Fetal alleles obtained from maternal plasma were double confirmed by genotyping paternal genomic DNA and fetal genomic DNA from amniocentesis. This study demonstrated that selective amplification strategy can be used to target cffDNA in maternal plasma, which will be a promising method for noninvasive prenatal paternity testing.
Detection of nucleotides in hydrated ssDNA via 2D h‐BN nanopore with ionic‐liquid/salt–water interface
Authors: Lee Jung Soo , Oviedo Juan Pablo , Bandara Yapa Mudiyanselage Nuwan Dhananjaya Yapa , Peng Xin , Xia Longsheng , Wang Qingxiao , Garcia Kevin , Wang Jinguo , Kim Min Jun , Kim Moon Jae
Published: February 2021

Accomplishing slow translocation speed with high sensitivity has been the most critical mission for solid‐state nanopore (SSN) device to electrically detect nucleobases in ssDNA. In this study, a method to detect nucleobases of ssDNA using a 2D SSN is introduced by considerably reducing the translocation speed and effectively increasing its sensitivity. The ultra‐thin titanium dioxide coated hexagonal boron nitride nanopore was fabricated, along with an ionic‐liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate/2.0 M KCl aqueous (cis/trans) interface, for increasing both the spatial and the temporal resolutions. As the ssDNA molecules entered the nanopore, a brief surge of electrical conductivity occurred, which was followed by multiple resistive pulses from nucleobases during the translocation of ssDNA and another brief current surge flagging the exit of the molecule. The continuous detection of nucleobases using a 2D SSN device is a novel achievement: the water molecules bound to ssDNA increased the molecular conductivity and amplified electrical signals during the translocation. Along with the experiment, computational simulations using COMSOL Multiphysics are presented to explain the pivotal role of water molecules bound to ssDNA to detect nucleobases using a 2D SSN.
An investigation of the effects of chaotic maps on the performance of metaheuristics
Authors: Gagnon Iannick , April Alain , Abran Alain
Published: February 2021

This article presents an empirical investigation of the effects of chaotic maps on the performance of metaheuristics. Particle Swarm Optimization and Simulated Annealing are modified to use chaotic maps instead of the traditional pseudorandom number generators and then compared on five common benchmark functions using nonparametric null hypothesis statistical testing. Contrary to what has often been assumed, results show that chaotic maps do not generally appear to increase the performance of swarm metaheuristics in a statistically significant way, except possibly for noisy functions. No performance differences were observed with the single‐state Simulated Annealing algorithm. Finally, it is shown that sequence effects may be responsible for the observed performance increase. These findings reveal new research directions in using chaotic maps for metaheuristics research. The MATLAB code used in this article is available in a GitHub repository for suggestions and/or corrections.
Analysis and optimization of concentrated solar power plant for application in arid climate
Authors: Elbeh Mutaz B. , Sleiti Ahmad K.
Published: February 2021

Abstract

In this research study, the concentrated solar power (CSP) technology is reviewed for designing and optimizing a CSP tower plant for arid climate regions such as Qatar. A database for all CSP projects around the world is created, and a spreadsheet model for calculating the available solar irradiance is developed. Two software packages are used for analyzing and optimizing the entire solar thermal plant and its cost, SolarPILOT, and System Advisor Model (SAM). Both packages are validated using data from a recent power tower project. A thorough iterative optimization process was developed and applied to optimize the solar field parameters of a suggested CSP plant including tower optical height; heliostat structure width and height; number of heliostats; horizontal and vertical panels; receiver height and diameter; water consumption; cleaning schedule; maintenance; and total cost. The results confirmed the feasibility of a CSP plant on 0.45 km2 of a solar field area with 2736 heliostats that produce 8 MWe with 10 hours of thermal storage and hybrid steam condensing system. It has been found that the highest production of the plant is in July, which is 3 621 950 kWh and the highest excess of electrical energy is in March, which is 2 946 965 kWh.
Back contacts materials used in thin film CdTe solar cells—A review
Authors: Hall Ralph Stephen , Lamb Dan , Irvine Stuart James Curzon
Published: February 2021

CdTe is the leading commercial thin film photovoltaic technology with current record laboratory efficiency (22.1%). However, there is much potential for progress toward the Shockley‐Queisser limit (32%). The best CdTe devices have short‐circuit current close to the limit but open‐circuit voltage has much room for improvement. Back contact optimization is likely to play a key role in any improvement. Back contact material choice is also influenced by their applicability in more complex architectures such as bifacial and tandem solar cells, where high visible and/or near‐infrared transparency is required in conjunction with their electrical properties. The CdTe research community has employed many back contact materials and processes to realize them. Excellent reviews of back contacts were published by McCandless and Sites (2011) and Kumar and Rao (2014). There have been numerous publications on CdTe back contacts since 2014. This review includes both recent and older literature to give a comprehensive picture. It includes a categorization of back contact interface materials into groups such as oxides, chalcogenides, pnictides, halides, and organics. The authors attempt to identify the more promising material groups. Attention is drawn to parallels with back contact materials used on other thin film photovoltaics such as perovskites and kesterites.
Variationally derived closure models for large eddy simulation of incompressible turbulent flows
Authors: Masud Arif , Zhu Lixing
Published: February 2021

We present a variationally consistent method for deriving residual‐based closure models for incompressible Navier–Stokes equations. The method is based on the fine‐scale variational structure facilitated by the variational multiscale framework where fine scales are driven by the residuals of the Euler–Lagrange equations of the resolved scales in the balance of momentum and conservation of mass equations. A bubble‐functions based approach is applied directly to the fine‐scale variational equation to derive analytical expressions for the closure model. Variational consistency of the model lends itself to rigorous linearization that results in quadratic rate of convergence of the method in the iterative solution strategy for the nonlinear equations. The method is shown to work for a family of linear and quadratic hexahedral and tetrahedral elements as well as composite discretizations that are comprised of hexahedral and tetrahedral elements in the same computational domain. Numerical tests with the proposed model are presented for various classes of turbulent flow problems to show its generality and range of applicability. The test cases investigated include Taylor–Green vortex stretching, statistically stationary wall‐bounded channel flows, and modeling the effects of the geometry of the leading edge of the plate on the instability of the boundary layer that leads to flow separation and flow reversal over flat plates of finite thickness.
Corporate social responsibility and supply chain: A study for evaluating corporate hypocrisy with special focus on stakeholders
Authors: Tiwari Mohit , Tiwari Tripti , Sam Santhose Samuel , Mishra Lokanath , MR Rejeesh , Sundararaj Vinu
Published: February 2021

Supply chains are intended to become the essential part of this global competitive world as organizations are seeking to formulate strategized advantages. To put it differently, most of the companies are aiming to adopt new businesses and raise the competition in the global market. For this, most of the companies or organizations are choosing strategies such as corporate social responsibility and supply chain management that allow the companies to ensure financial strengthening. Moreover, stakeholders and customers have raised their concerns towards corporate social responsibility with respect to global supply chain and ensured to act in a socially responsible way. It is believed that majority of the organizations are placing high importance on implementing corporate social responsibility or CSR activities in order to enhance the whole business. The active participation of companies in CSR activities will always benefit them in terms of profit, virtues and other moral standards. Usually, corporate firms exhibit their virtues ignoring the moral standard, which eventually reveals the nature of hypocrisy. Corporate hypocrisy is a context when companies or organizations assure the public to do something in corporate social responsibility context and end up doing entirely different. Keeping this in mind, the current study aims to reveal the hidden nature of corporate hypocrisy and its effect on inner stakeholders explicitly focusing on the employees' observations on corporate hypocrisy; examine the hypocritical behaviour of the reputed firms towards the consumers, which in turn affects the supply chain globally. For this, data analysis will be carried out with consumer firms across countries. Results show that firms are completely held responsible for their behaviour eventually defaming reputation.
Controlling shareholders' influence on acquisition decisions and value creation: An empirical study from China
Authors: Opoku‐Mensah Evans , Yin Yuming
Published: February 2021

Controlling shareholders are capable of influencing major decisions in firms, and their existence may give rise to principal‐to‐principal conflict as minority shareholders may feel sidelined during decision‐making. This study employs a proxy (the highest control right), which takes into consideration both direct and indirect controls to investigate the excess cash usage preference of controlling shareholders. Again, the study investigates how the background characteristics of different controlling shareholders influence their underlying firms' acquisition decisions. With observations from 13,293 Chinese firms and the random effect probit model, we find that controlling shareholders are more likely to influence the use of excess cash into acquisition activities other than to retain such cash in the firm possibly for the payment of a dividend. Furthermore, we observe that the traditional way of classifying firms into either private or state is misleading, and the use of excess cash is influenced by the unique characteristics of the true owner. We recommend that on‐going reforms in China should consider encouraging more institutional investors to acquire shares as this will reduce the powers of controlling owners.
Optimal fiscal management in an economy with resource revenue‐financed government‐linked companies
Authors: Lim King Yoong , Zhang Shuonan
Published: February 2021

We present a dynamic stochastic general equilibrium (DSGE) model in which a resource‐rich government allocates its excess resource rents between a resource stabilization fund and the facilitation of costly domestic fund‐raising activities of sovereign wealth funds (SWF), which holds a portfolio of government‐linked companies (GLCs). Despite being less productive efficient, GLCs' operation benefits from scale economies tied to the resource sector: its profitability is procyclical to commodity shocks. The model is estimated to Malaysia using the Bayesian approach, with the results suggesting a business cycle heavily influenced by resource shocks. Based on this, we solve numerically for a socially optimal combination of excess resource savings allocation. We find the present allocation to be sub‐optimal, regardless of the structural shocks. This suggests that the Malaysian economy might have hit its absorptive capacity constraint (i.e., a domestic economy saturated by GLCs).
Compliance or non‐compliance during financial crisis: Does it matter?
Authors: Ahmad Sardar , Akbar Saeed , Kodwani Devendra , Halari Anwar , Shah Syed Zubair
Published: February 2021

This paper investigates whether shareholder value is affected by non‐compliance with the prescriptions of a principle‐based ‘comply or explain’ system of corporate governance in the context of the global financial crisis of 2007–2009. Using System Generalized Method of Moments estimates to control for different types of endogeneity, the main findings of this paper suggest that non‐compliance with the UK Corporate Governance Code adversely affects shareholder value. Furthermore, ex‐post estimates reveal that compliance with certain corporate governance mechanisms is more beneficial than others. With regard to this, compliance with provisions related to board independence is more important than complying with performance‐related pay requirements of the code. These findings have implications for policy makers and financial institutions regarding the usefulness of compliance with a prescribed code of corporate governance, specifically during periods of financial distress.
Plasma miR‐218a‐5p as a biomarker for acute cholestatic liver injury in rats and investigation of its pathophysiological roles
Authors: Oda Shingo , Hirabuki Yuka , Takeuchi Taiki , Kagawa Takumi , Yokoi Tsuyoshi
Published: February 2021

MicroRNAs (miRNA) have received considerable attention as potential biomarkers for drug‐induced liver injury. We recently reported that the plasma levels of miR‐143‐3p and miR‐218a‐5p increased in severe cholestasis in rats. This study aimed to investigate whether these miRNAs increase in a severity‐dependent manner and to elucidate their pathophysiological roles in cholestasis. Male Sprague–Dawley rats were orally administered different doses of α‐naphthylisothiocyanate or 4,4‐methylenedianiline to induce acute cholestasis. They were also orally administered acetaminophen or thioacetamide to induce hepatocellular injury. We found that plasma miR‐143‐3p and miR‐218a‐5p levels increased in a dose‐dependent manner in cholestatic rats but not in hepatocellular injury. Bioinformatic analysis provided putative target genes of hsa‐miR‐218‐5p, rno‐miR‐218a‐5p, and mmu‐miR‐218‐5p, among which GNAI2, PPP1CB, and PPP2R5A were experimentally validated as their direct target genes in human cholangiocyte line MMNK‐1. Proliferation of MMNK‐1 cells was significantly suppressed after overexpression of miR‐218‐5p and transduction of siRNAs for GNAI2, PPP1CB, and PPP2R5A. In the cholestatic livers of rats, Ppp1cb and Ppp2r5a expression levels decreased, whereas Gnai2 expression levels increased compared with those in vehicle‐treated rats, suggesting that Ppp1cb and Ppp2r5a may be under the control of miR‐218a‐5p in vivo. In conclusion, our data suggest that miR‐218(a)‐5p is involved in the suppression of cholangiocyte proliferation by inhibiting the expression of PPP1CB and PPP2R5A, thereby contributing to the pathogenesis of cholestasis; and miR‐218a‐5p leaks into the plasma probably from damaged cholangiocytes in a severity‐dependent manner in rats. Therefore, miR‐218a‐5p overexpression could be one of the underlying mechanisms of acute cholestatic liver injury in rats.
Sexual Dimorphism in Differentiating Osteoclast Precursors Demonstrates Enhanced Inflammatory Pathway Activation in Female Cells
Authors: Mun Se Hwan , Jastrzebski Sandra , Kalinowski Judy , Zeng Steven , Oh Brian , Bae Seyeon , Eugenia Giannopoulou , Khan Nazir M , Drissi Hicham , Zhou Ping , Shin Bongjin , Lee Sun-Kyeong , Lorenzo Joseph , Park-Min Kyung-Hyun
Published: February 2021

Sexual dimorphism of the skeleton is well documented. At maturity, the male skeleton is typically larger and has a higher bone density than the female skeleton. However, the underlying mechanisms for these differences are not completely understood. In this study, we examined sexual dimorphism in the formation of osteoclasts between cells from female and male mice. We found that the number of osteoclasts in bones was greater in females. Similarly, in vitro osteoclast differentiation was accelerated in female osteoclast precursor (OCP) cells. To further characterize sex differences between female and male osteoclasts, we performed gene expression profiling of cultured, highly purified, murine bone marrow OCPs that had been treated for 3 days with macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL). We found that 125 genes were differentially regulated in a sex-dependent manner. In addition to genes that are contained on sex chromosomes, transcriptional sexual dimorphism was found to be mediated by genes involved in innate immune and inflammatory response pathways. Furthermore, the NF-κB-NFATc1 axis was activated earlier in female differentiating OCPs, which partially explains the differences in transcriptomic sexual dimorphism in these cells. Collectively, these findings identify multigenic sex-dependent intrinsic difference in differentiating OCPs, which results from an altered response to osteoclastogenic stimulation. In humans, these differences could contribute to the lower peak bone mass and increased risk of osteoporosis that females demonstrate relative to males. © 2021 American Society for Bone and Mineral Research (ASBMR).
Sodium salts effect on the time of flight mass spectra of some amino acids in the direct‐laser desorption ionization and matrix‐assisted laser desorption/ionization
Authors: Amiri Razieh , Farrokhpour Hossein , Tabrizchi Mahmoud
Published: February 2021

One of the problems in the matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF MS) of small molecules is the overlap between the peaks originated from the matrix and analyte. The MALDI and the direct laser desorption ionization (direct‐LDI) spectrum of the phenylalanine amino acid (FAA) has been recorded and assigned in the absence and presence of the salts, including NaF and NaOH. It was seen that the peaks originated from the matrix were suppressed in the MALDI spectrum of the FFA in the presence of salt. In addition, the salt effect on the TOF mass spectrum of the FAA, recorded by the direct‐LDI, was investigated. The mass spectrum of the FFA, in the presence of NaF, showed a relatively strong and sharp peak assigned to [FAA‐H + 2Na]+ species in both the direct‐LDI and MALDI. The direct‐LDI spectrum was less crowded than the MALDI spectrum. The same results were obtained when NaOH was used instead of NaF. The peak related to [Amino acid‐H + 2Na]+ species was considered a characteristic peak in both the direct‐LDI and MALDI of the selected amino acids in the presence of NaF and NaOH.
A pilot evaluation of the Building Early Emotional Skills (BEES) curriculum in face‐to‐face and online formats
Authors: Brophy‐Herb Holly E. , Moyses Kendra , Shrier Carrie , Rymanowicz Kylie , Pilkenton Alan , Dalimonte‐Merckling Danielle , Hetherington Chelsea , Mitchell Koi
Published: February 2021

The Building Early Emotional Skills (BEES) parenting program is designed to promote parent–child relationships and more optimal social‐emotional development by addressing four sequentially built skills in parenting infants/toddlers: (1) building parental awareness of emotions in self and child; (2) listening and interacting sensitively; (3) identifying and labeling emotions; and (4) intentionally supporting early self‐regulation skills. BEES used an 8‐session format delivered in online or face‐to‐face platforms (N = 264 female caregivers; n = 214 online, n = 50 face‐to‐face). Linear mixed modeling for pre‐to‐post changes showed significant increases in knowledge, emotion coaching beliefs, acceptance of negative emotions, and self‐reported emotionally supportive responses to emotions; and, significant decreases in rejection of emotions, emotionally unsupportive responses, and parenting distress. Results suggested no differences in rate of change by program delivery type. Caregivers with more depressive symptoms showed greater improvement in their parenting distress. The BEES program may be a tool to support early positive parenting.
Osteoimmunological insights into the pathogenesis of ankylosing spondylitis
Authors: Liu Lifei , Yuan Yu , Zhang Shihua , Xu Jiake , Zou Jun
Published: February 2021

Ankylosing spondylitis (AS) is inflammatory arthritis predominantly affecting the spine, which is involved in the disorders of both immune and skeletal systems. The exact pathogenesis of AS is not fully understood. Osteoimmunology is a new subject of study in inflammatory arthritis, in particular the pathogenic events involved in the cross‐regulation of both skeletal and immune systems. In this review, we discuss osteoimmunological and pathological changes of AS in the spine that are characterized by altered osteogenesis and osteolytic bone destruction, accompanied by the changes of the immune system. It was revealed that bone cells like mesenchymal stem cells, osteoblast, and osteoclast in crossing talking with immune cells such as T cells, B cells coregulate to the pathogenesis of AS. Further, an array of cytokines and molecules expressed by both skeletal and immune systems contribute to these complex interplays. Understanding the cellular and molecular mechanisms underlying the pathogenesis of AS will lay a foundation for the exploration of the potential new treatment to AS.
Efficient removal of Pb(II) ions from aqueous solution by using a novel functionalized bio‐material with two tridentate coordinated units
Authors: Guo Yu , Xiao Yu , Wu Hongmei , Xu Jingwen , Chen Qiangqiang
Published: February 2021

BACKGROUND

Pb(II)‐containing wastewater causes serious pollution in our daily life. Adsorption is the technique most often used to remove heavy metals from aqueous solution. For improving the removal efficiency of Pb(II) ions from aqueous solution, adsorbent materials and the functionalization method of the adsorbent need to be further studied.

RESULTS

A novel Schiff's base functionalized bio‐material (DAS2‐AT) with two tridentate coordinated units was synthesized by the reaction of 2‐acetylthiophene and modified dialdehyde starch (DAS‐NH2) for the adsorption of Pb(II) ions from aqueous solution. Experimental results demonstrated that the DAS2‐AT exhibited high adsorption capacity and selectivity towards Pb(II), and the maximum adsorption capacity was up to 203 mg g−1. The adsorption isotherms and kinetic of Pb(II) ions on the DAS2‐AT were correlated well with the Langmuir isotherm model and Pseudo‐second‐order model. Moreover, thermodynamic analysis indicated that the adsorption process is spontaneous and endothermic. Desorption and regeneration experiments indicated that DAS2‐AT has good reusability. Besides that, the adsorbent displayed good affinity of DAS2‐AT towards Pb(II) ion in the presence of Cr(VI), Zn(II), and Ni(II) ions.

CONCLUSION

The bio‐adsorbent (DAS2‐AT) displayed good adsorption performance to remove Pb(II) ions from aqueous solution. DAS2‐AT gave a potential application as a low‐cost and effective adsorbent. © 2021 Society of Chemical Industry
The dermal armor of mylodontid sloths (Mammalia, Xenarthra) from Cueva del Milodón (Última Esperanza, Chile)
Authors: Toledo Néstor , Boscaini Alberto , Pérez Leandro Martín
Published: February 2021

Dermal ossifications (osteoderms, dermal ossicles, osteoscutes) appear independently in various tetrapod lineages. In mammals, however, dermal ossifications are only present in some members of Xenarthra. This clade includes Cingulata (armadillos and their relatives), and Pilosa, including Vermilingua (anteaters) and Folivora (sloths). In extant xenarthrans, osteoderms are invariably present in cingulates whereas they are absent in pilosans. Among extinct sloths, however, a limited number of taxa possessed dermal ossifications. Records of mummified skins of ground sloths bearing osteoderms found in Cueva del Milodón (Southern Chile), with a late Pleistocene age, allowed us to analyze their micro‐ and macroscopic morphology. The main goal of this study is to closely examine a portion of a mylodontid skin portion using radiography. The arrangement, morphology and internal structure of the ossicles are analyzed and the results are discussed in the context of previous research. The results we obtained indicate that ossicles vary in shape and size, and the integument has four different patterns of arrangement of the ossicles: that is, areas without ossicles, disorganized ossicles, rows, and mosaic areas. The latter has two variants, with clusters of ossicles forming rosettes or stars. Thin sections of the ossicles allowed us to recognize and describe anatomical features of the bone and its mode of growth. Finally, paleobiological and functional considerations of the dermal armor are discussed along with its phylogenetic and chronological implications.
Dynamic Changes in Functional Network Connectivity Involving Amyotrophic Lateral Sclerosis and Its Correlation With Disease Severity
Authors: Chen Hua‐Jun , Zou Zhang‐Yu , Zhang Xiao‐Hong , Shi Jia‐Yan , Huang Nao‐Xin , Lin Yan‐Juan
Published: February 2021

Background

Aberrant static functional connectivity (FC) has been well demonstrated in amyotrophic lateral sclerosis (ALS); however, ALS‐related alterations in FC dynamic properties remain unclear, although dynamic FC analyses contribute to uncover mechanisms underlying neurodegenerative disorders.

Purpose

To explore dynamic functional network connectivity (dFNC) in ALS and its correlation with disease severity.

Study Type

Prospective.

Subjects

Thirty‐two ALS patients and 45 healthy controls.

Field Strength/Sequence

Multiband resting‐state functional images using gradient echo echo‐planar imaging and T1‐weighted images were acquired at 3.0 T.

Assessment

Disease severity was evaluated with the revised ALS Functional Rating Scale (ALSFRS‐R) and patients were stratified according to diagnostic category. Independent component analysis was conducted to identify the components of seven intrinsic brain networks (ie, visual/sensorimotor (SMN)/auditory/cognitive‐control (CCN)/default‐mode (DMN)/subcortical/cerebellar networks). A sliding‐window correlation approach was used to compute dFNC. FNC states were determined by k‐mean clustering, and state‐specific FNC and dynamic indices (fraction time/mean dwell time/transition number) were calculated.

Statistical Tests

Two‐sample t test used for comparisons on dynamic measures and Spearman's correlation analysis.

Results

ALS patients showed increased FNC between DMN‐SMN in state 1 and between CCN‐SMN in state 4. Patients remained in state 2 (showing the weakest FNC) for a significantly longer time (mean dwell time: 49.8 ± 40.1 vs. 93.6 ± 126.3; P < 0.05) and remained in state 1 (showing a relatively strong FNC) for a shorter time (fraction time: 0.27 ± 0.25 vs. 0.13 ± 0.20; P < 0.05). ALS patients exhibited less temporal variability in their FNC (transition number: 10.2 ± 4.4 vs. 7.8 ± 3.8; P < 0.05). A significant correlation was observed between ALSFRS‐R and mean dwell time in state 2 (r = −0.414, P < 0.05) and transition number (r = 0.452, P < 0.05). No significant between‐subgroup difference in dFNC properties was found (all P > 0.05).

Data Conclusion

Our findings suggest aberrant dFNC properties in ALS, which is associated with disease severity.

Level of Evidence

2

Technical Efficacy

Stage 3
Combined Hepatocellular‐Cholangiocarcinoma: Magnetic Resonance Imaging Features and Prognosis According to Risk Factors for Hepatocellular Carcinoma
Authors: Kim Dong Hwan , Choi Sang Hyun , Kim Dong Wook , Lee Seung Soo , Lim Young‐Suk , Kim So Yeon , Kim Hyoung Jung , Kim Jin Hee , Byun Jae Ho
Published: February 2021

Background

Combined hepatocellular‐cholangiocarcinoma (cHCC‐CCA) can develop in patients with and without risk factors for hepatocellular carcinoma (HCC).

Purpose

To compare the clinical and magnetic resonance imaging (MRI) characteristics of cHCC‐CCA in patients with and without risk factors for HCC, and to assess the influence of risk factors on patient prognosis.

Study Type

Retrospective.

Population

A total of 152 patients with surgically confirmed cHCC‐CCA.

Field Strength/Sequence

1.5‐T and 3‐T/T1‐weighted dual gradient‐echo in‐ and opposed‐phase, T2‐weighted turbo‐spin‐echo, diffusion‐weighted single‐shot spin‐echo echo‐planar, and T1‐weighted three‐dimensional gradient‐echo contrast‐enhanced sequences.

Assessment

MRI features according to the Liver Imaging Reporting and Data System (LI‐RADS) and pathologic findings based on revised classification were compared between patients with and without risk factors for HCC. Overall survival (OS) and recurrence‐free survival (RFS) were also compared between the two groups, and factors associated with survival were evaluated.

Statistical Tests

The clinico‐pathologic and MRI features of the two groups were compared using Student's t‐tests, Mann–Whitney U‐tests, and chi‐square tests. OS and RFS were evaluated by the Kaplan–Meier method, and factors associated with survival were evaluated by Cox proportional hazard model.

Results

cHCC‐CCA in patients with risk factors were more frequently classified as LI‐RADS category 4 or 5 (LR‐4/5; probably or definitely HCC) (48.7%), whereas those without risk factors were more frequently classified as category M (LR‐M; probably malignant, not specific for HCC) (63.6%). RFS and OS did not differ significantly according to risk factors (P = 0.63 and 0.83). Multivariable analysis showed that pathologic tumor type (hazard ratio 2.02; P < 0.05) and LI‐RADS category (hazard ratio 2.19; P < 0.05) were significantly associated with RFS and OS, respectively.

Data Conclusion

Although MRI features of cHCC‐CCA differed significantly between patients with and without risk factors for HCC, postsurgical prognosis did not. LI‐RADS category and pathologic tumor type were independently correlated with postsurgical prognosis in patients with cHCC‐CCA.

Level of Evidence

3

Technical Efficacy Stage

2
Deep Learning With 3D Convolutional Neural Network for Noninvasive Prediction of Microvascular Invasion in Hepatocellular Carcinoma
Authors: Zhang Yongxin , Lv Xiaofei , Qiu Jiliang , Zhang Bin , Zhang Lu , Fang Jin , Li Minmin , Chen Luyan , Wang Fei , Liu Shuyi , Zhang Shuixing
Published: February 2021

Background

Microvascular invasion (MVI) is a critical prognostic factor of hepatocellular carcinoma (HCC). However, it could only be obtained by postoperative histological examination.

Purpose

To develop an end‐to‐end deep‐learning models based on MRI images for preoperative prediction of MVI in HCC patients who underwent surgical resection.

Study type

Retrospective.

Population

Two hundred and thirty‐seven patients with histologically confirmed HCC.

Field strength

1.5 T and 3.0 T.

Sequence

Axial T2‐weighted (T2‐w) with turbo spin echo sequence, T2‐Spectral Presaturation with Inversion Recovery (T2‐SPIR), and dynamic contrast‐enhanced (DCE) imaging with fat suppressed enhanced T1 high‐resolution isotropic volume examination.

Assessment

The patients were randomly divided into training (N = 158) and validation (N = 79) sets. Data augmentation by random rotation was performed on the training set and the sample size increased to 1940 for each MR sequence. A three‐dimensional convolutional neural network (3D CNN) was used to develop four deep‐learning models, including three single‐layer models based on single‐sequence, and fusion model combining three sequences. MVI status was obtained from the postoperative pathology reports.

Statistical Tests

The dice similarity coefficient (DSC) and Hausdorff distance (HD) were applied to assess the similarity and reproducibility between the manual segmentations of tumor from two radiologists. Receiver operating characteristic curve analysis was used to evaluate model performance. MVI was identified in 92 (38.8%) patients. Good reproducibility with interobserver DSCs of 0.90, 0.89, and 0.89 and HDs of 4.09, 3.67, and 3.60 was observed for PVP, T2WI, and T2‐SPIR, respectively. The fusion model achieved an area under the curve (AUC) of 0.81, sensitivity of 69%, and specificity of 79% in the training set and 0.72, sensitivity of 55%, and specificity of 81% in the validation set.

Data Conclusion

3D CNN model may serve as a noninvasive tool to predict MVI in HCC, whereas its accuracy needs to be enhanced with larger cohort.

Level of Evidence

3

Technical Efficacy

Stage 2
Repeatability of dynamic 3D phase‐resolved functional lung (PREFUL) ventilation MR Imaging in patients with chronic obstructive pulmonary disease and healthy volunteers
Authors: Klimeš Filip , Voskrebenzev Andreas , Gutberlet Marcel , Obert Arnd J. , Pöhler Gesa H. , Grimm Robert , Behrendt Lea , Crisosto Cristian , Glandorf Julian , Moher Alsady Tawfik , Wacker Frank , Vogel‐Claussen Jens
Published: February 2021

Background

A previous study has demonstrated the feasibility of 3D phase‐resolved functional lung (PREFUL) MRI in healthy volunteers and patients with chronic pulmonary disease. Before clinical use, the repeatability of the ventilation parameters derived from 3D PREFUL MRI must be determined.

Purpose

To evaluate repeatability of 3D PREFUL and to compare with pulmonary functional lung testing (PFT).

Study Type

Prospective.

Population

Fifty‐three healthy subjects and 13 patients with chronic obstructive pulmonary disease (COPD).

Field Strength/Sequence

A prototype 3D stack‐of‐stars spoiled‐gradient‐echo sequence at 1.5 T.

Assessment

Study participants underwent repeated MRI examination (median time interval between scans COPD/healthy subjects [interquartile range]: 7/0 days [6–8/0–0 days]) and one PFT carried out at the time of the baseline MRI. For 3D PREFUL, regional ventilation (RVent) and flow‐volume loops were computed and rated by cross‐correlation (CC). Also, ventilation time‐to‐peak (VTTP) was computed. Ventilation defect percentage (VDP) maps were obtained for RVent and CC.

Statistical Tests

Repeatability of 3D PREFUL parameters was evaluated using Bland–Altman analysis, coefficient of variation (COV) and intraclass correlation coefficient (ICC). The relation between 3D PREFUL and PFT measures (forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) was assessed using the Pearson correlation coefficient (r).

Results

In healthy subjects and COPD patients, no significant bias (all P range: 0.09–0.77) and a moderate to good repeatability of RVent, VTTP, and VDPRVent were found (COV range: 0.1%–18.2%, ICC range: 0.51–0.88). For CC and VDPCC moderate repeatability was found (COV range: 0.6%–43.6%, ICC: 0.38–0.60). CC, VDPRVent, and VDPCC showed a good correlation with FEV1 (all |r| > 0.58, all P < 0.05) and FEV1/FVC ratio (all |r| > 0.62, all P < 0.05).

Data Conclusion

3D PREFUL provided a good repeatability of RVent, VTTP, and VDPRVent and moderate repeatability of CC and VDPCC in healthy volunteers and COPD patients, and correlated well with FEV1 and FEV1/FVC.

Level of Evidence

2

Technical Efficacy Stage

2
Characterisation of copal resin and amber by negative‐ion electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry
Authors: Tian Yankuan , Sun Jia‐Nan , Jiang Bin , Zhan Zhao‐Wen
Published: February 2021

Copal resin and amber from Columbia were analysed by negative‐ion electrospray ionisation (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR MS), with particular focus on polar compounds with relatively high molecular weights. A total of 4038 and 2755 compounds were identified between m/z 150 and 1,000 in the spectra of the copal resin and amber DCM extracts, respectively. The CHO classes were the most abundant species in the detected polar compounds. The petrochemical process of converting copal resin to amber is accompanied by evaporation and dispersion of volatile molecules and polymerisation of relatively smaller molecules. Thus, the most abundant compounds in copal resin comprised more than one C5 basic unit compared to amber, and the relative abundances of compounds with a high number of carbon and oxygen atoms in amber were higher than those in copal resin. There were strong positive correlations between the double‐bond equivalence (DBEav) values and the number of oxygen atoms in both samples. The slopes and y‐intercepts of the linear relationship indicated that the C5 pentadienoic acid is the basic structure of heteroatom compound molecules in copal resin and amber. FT‐ICR MS analysis focuses on the characterisation of heteroatom compounds with relatively high molecular weight and is helpful to provide supplementary information on the origin and evolution of complex organic mixtures such as copal resin and amber at the molecular level in a fast and convenient way.
Multi‐coil electromagnets: An accurate magnetic equivalent circuit, cost, and energy management
Authors: Hashemi Ali , Yazdanpanah Qaraei Parsa
Published: February 2021

Using nonintegrated multiple coils in an electromagnet is a way to manage energy and reduce maintenance costs. In order to model and analyze the lifting force and the magnetic field in different zone of the electromagnet, an exact magnetic equivalent circuit (MEC) is required. In this paper, an accurate MEC to analyze dual‐coil electromagnets is presented. MATLAB and ANSYS MAXWELL software are used to analyze the proposed MEC and simulate the magnetic field and the lifting force, respectively. In multi‐coil electromagnets, if a coil burns out, the electromagnet will still be able to lift the loads with a percentage of the nominal load weight. Also, it is only necessary to replace the burned coil, which reduces the maintenance costs of the electromagnet. Flexibility in winding excitation is another advantage of using multiple coils in electromagnets. In this case, one or more coils can be excited according to the weight of the load. This feature not only increases the lifetime of the coils but also reduces the energy consumption of the electromagnet and no need to use expensive power electronic converters to continuously control the current of coils. To evaluate the proposed MEC, the laboratory platform of an electromagnet was made to lift a load of 100 kg in the air gap of 2 mm and tested in two modes, single‐coil and dual‐coil. The analytical, simulation, and experimental results have very good agreement, indicating the high accuracy of the proposed MEC.
Analysis of behaviour and relationship of four daily precipitation concentration indices according to Mexico's precipitation
Authors: Núñez‐González Gerardo
Published: February 2021

In recent years, the field of precipitation concentration has garnered significant research interest owing to the importance of precipitation for economic activities related to agriculture, energy production, and drinking water supply management. For the study and characterization of precipitation concentration, different approaches have been defined, such as consideration of the concentration index (CI), Theil index (TI), Q index (QI), and precipitation concentration degree (PCD) index. However, in the literature, there is only one study that evaluates the performance of the CI and TI in conjunction on a spatial basis. Another study evaluates the behaviour of the QI and PCD indices on a temporal basis. Thus, the objective of this work was to analyse the behaviour of the four indices both on temporal and spatial scales according to Mexico's precipitation. Results show that the four indices can detect, in a similar manner, the concentration degree of regions with different rainfall regimes, each within its own variability. A lower range of variability was found for the TI, while the highest was found for the CI and the PCD index. In addition, the PCD index showed high sensitivity within its concentration degree when calculated for different time intervals. The results of the temporal and spatial correlation analysis show a very high correlation between the CI and TI, and moderate and low correlations among the other indices. Low correlations can be attributed to the differences in the theoretical bases of each index. Although low correlations were shown for some indices, the results indicate that these can be used in a complementary manner to improve the precipitation concentration analysis on temporal and spatial scales.