bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial Characteristics of Recycled and Primordial Reservoirs in the Deep Mantle
Authors: Jackson M. G. , Becker T. W. , Steinberger B. 
Published: January 2021

AbstractThe spatial distribution of the geochemical domains hosting recycled crust and primordial (high‐3He/4He) reservoirs, and how they are linked to mantle convection, are poorly understood. Two continent‐sized seismic anomalies located near the core‐mantle boundary—called the Large Low Shear Wave Velocity Provinces (LLSVPs)—are potential geochemical reservoir hosts. It has been suggested that high‐3He/4He hotspots are spatially confined to the LLSVPs, hotspots sampling recycled continental crust are associated with only one of the LLSVPs, and recycled continental crust shows no relationship with latitude. We reevaluate the links between LLSVPs and isotopic signatures of hotspot lavas using improved mantle flow models including plume conduit advection. While most hotspots with the highest‐3He/4He can indeed be traced to the LLSVP interiors, at least one high‐3He/4He hotspot, Yellowstone, is located outside of the LLSVPs. This suggests high‐3He/4He is not geographically confined to the LLSVPs. Instead, a positive correlation between hotspot buoyancy flux and maximum hotspot 3He/4He suggests that it is plume dynamics (i.e., buoyancy), not geography, which determines whether a dense, deep, and possibly widespread high‐3He/4He reservoir is entrained. We also show that plume‐fed EM hotspots (enriched mantle, with low‐143Nd/144Nd), signaling recycled continental crust, are spatially linked to both LLSVPs, and located primarily in the southern hemisphere. Lastly, we confirm that hotspots sampling HIMU (“high‐μ,” or high 238U/204Pb) domains are not spatially limited to the LLSVPs. These findings clarify and advance our understanding of deep mantle reservoir distributions, and we discuss how continental and oceanic crust subduction is consistent with the spatial decoupling of EM and HIMU.
Species‐dependent Response of the Martian Ionosphere to the 2018 Global Dust Event
Authors: Niu D.‐D. , Cui J. , Wu S.‐Q. , Gu H. , Cao Y.‐T. , Wu Z.‐P. , Wu X.‐S. , Zhong J.‐H. , Wu M.‐Y. , Wei Y. , Zhang T.‐L. 
Published: January 2021

AbstractGlobal dust storms (GDS) are an important dynamical phenomenon of the Martian lower atmosphere but are known to have important impacts on the Martian middle/upper atmosphere and ionosphere. Despite extensive studies over the past several decades, how the composition of the Martian ionosphere is modified during the GDS has only been studied from a theoretical point of view. Here we present for the first time the observations of the compositional variation of the Martian ionosphere during the GDS in 2018, using the ion density measurements made by the Neutral Gas and Ion Mass Spectrometer onboard the Mars Atmosphere and Volatile Evolution. At a representative altitude of 170 km, the variations of ionospheric species during the GDS show either enhancement (, Ar+, , H2O+, , ArH+) or depletion (, O+, /CO+, OH+). Despite the apparent diversity, the observations are mostly understandable within the established framework of ionospheric chemistry on Mars, which further demonstrates that the variation of ion species during the GDS is a good diagnostic of the variation of relevant neutral species in the thermosphere. In particular, the observed ionospheric variation strongly supports a scenario that H2O is substantially enhanced in the Martian thermosphere during the GDS. However, the variations of and are inconsistent with predictions from ionospheric chemistry and require further investigation.
Fuzzy Ensemble Clustering Approach to Address Regionalization Uncertainties in Flood Frequency Analysis
Authors: Kiran K. G. , Srinivas V. V. 
Published: January 2021

AbstractVarious regionalization approaches are in use to delineate watersheds in an area into homogeneous groups/regions for regional frequency analysis of hydrologic extremes (floods, droughts). Each approach differs in the underlying assumptions and strategy for regionalization and yields regions that differ in composition. There is ambiguity in the choice of approaches, as none is established to be universally superior in yielding true regions that are unknown. This article proposes a novel fuzzy ensemble clustering (FEC) approach to deal with uncertainty in the composition of regions obtained using different regionalization approaches. It forms fuzzy meta‐regions by integrating information on similarities in watershed groupings found in an ensemble of regions derived using several regionalization approaches. The FEC approach's potential to form effective regions (than those found in the ensemble) and their utility in regional flood frequency analysis to predict flood quantiles at ungauged sites is demonstrated through Monte Carlo simulation experiments and a case study on peninsular India. An ensemble of regions for use with FEC is formed using the region of influence approach, clustering approach based on Gaussian mixture model (GMM), and a hybrid approach which combines canonical correlation analysis with GMM based clustering. The FEC is shown to be effective in grouping similar watersheds even when the ensemble comprises regions having some improperly/wrongly grouped watersheds.
Unravelling the potency of triazole analogues for inhibiting α-synuclein fibrillogenesis andin vitrodisaggregation
Authors: Maqbool Mudasir , Gadhavi Joshna , Singh Anju , Hivare Pravin , Gupta Sharad , Hoda Nasimul 
Published: January 2021

Triazole-based compounds as inhibitors and disaggregators of α-synuclein.
Hyperglycemia at admission is a strong predictor of mortality and severe/critical complications in COVID-19 patients: a meta-analysis
Authors: Yang Yan , Cai Zixin , Zhang Jingjing 
Published: January 2021

Abstract
Background: Hyperglycemia at admission has been demonstrated to exacerbate the outcomes of coronavirus disease 2019 (COVID-19) but a meta-analysis is lacking to further confirm this hypothesis. The purpose of this meta-analysis was to summarize the evidence on the association between hyperglycemia at admission and the development of COVID-19. Method: Four databases namely, PubMed, Web of Science, Embase and Cochrane Library, were screened for eligible studies. STATA software was utilized to pool data for this meta-analysis. The primary outcomes included mortality and severity. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with random-effects models, and the quality of evidence was appraised by the Newcastle–Ottawa Scale (NOS). This meta-analysis was prospectively registered online on PROSPERO, CRD42020191763. Results: Sixteen observational studies with 6386 COVID-19 patients relating hyperglycemia at admission to COVID-19 outcomes were included. The overall data demonstrated that, compared with the control, the hyperglycemia at admission group was more likely to have increased mortality (OR = 3.45, 95% CI, 2.26–5.26) and severe/critical complications (OR = 2.08, 95% CI, 1.45–2.99) of COVID-19. Conclusion: Hyperglycemia at admission in COVID-19 patients may be a strong predictor of mortality and complications.
Acid sphingomyelinase promotes SGK1-dependent vascular calcification
Authors: Luong Trang Thi Doan , Tuffaha Rashad , Schuchardt Mirjam , Moser Barbara , Schelski Nadeshda , Boehme Beate , Gollmann-Tepeköylü Can , Schramm Clara , Holfeld Johannes , Pieske Burkert , Gulbins Erich , Tölle Markus , van der Giet Markus , Lang Florian , Eckardt Kai-Uwe , Voelkl Jakob , Alesutan Ioana 
Published: January 2021

Abstract
In chronic kidney disease (CKD), hyperphosphatemia is a key factor promoting medial vascular calcification, a common complication associated with cardiovascular events and high mortality. Vascular calcification involves osteo-/chondrogenic transdifferentiation of vascular smooth muscle cells (VSMCs), but the complex signaling events inducing pro-calcific pathways are incompletely understood. The present study investigated the role of acid sphingomyelinase (ASM)/ceramide as regulator of VSMC calcification. In vitro, both, bacterial sphingomyelinase and phosphate increased ceramide levels in VSMCs. Bacterial sphingomyelinase as well as ceramide supplementation stimulated osteo-/chondrogenic transdifferentiation during control and high phosphate conditions and augmented phosphate-induced calcification of VSMCs. Silencing of serum- and glucocorticoid-inducible kinase 1 (SGK1) blunted the pro-calcific effects of bacterial sphingomyelinase or ceramide. Asm deficiency blunted vascular calcification in a cholecalciferol-overload mouse model and ex vivo isolated-perfused arteries. In addition, Asm deficiency suppressed phosphate-induced osteo-/chondrogenic signaling and calcification of cultured VSMCs. Treatment with the functional ASM inhibitors amitriptyline or fendiline strongly blunted pro-calcific signaling pathways in vitro and in vivo. In conclusion, ASM/ceramide is a critical upstream regulator of vascular calcification, at least partly, through SGK1-dependent signaling. Thus, ASM inhibition by repurposing functional ASM inhibitors to reduce the progression of vascular calcification during CKD warrants further study.
β-blockade prevents coronary macro- and microvascular dysfunction induced by a high salt diet and insulin resistance in the Goto–Kakizaki rat
Authors: Pearson James T. , Thambyah Hamish P. , Waddingham Mark T. , Inagaki Tadakatsu , Sukumaran Vijayakumar , Ngo Jennifer P. , Ow Connie P.C. , Sonobe Takashi , Chen Yi Ching , Edgley Amanda J. , Fujii Yutaka , Du Cheng-Kun , Zhan Dong-Yun , Umetani Keiji , Kelly Darren J. , Tsuchimochi Hirotsugu , Shirai Mikiyasu 
Published: January 2021

Abstract
A high salt intake exacerbates insulin resistance, evoking hypertension due to systemic perivascular inflammation, oxidative-nitrosative stress and endothelial dysfunction. Angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blockers (ARBs) have been shown to abolish inflammation and redox stress but only partially restore endothelial function in mesenteric vessels. We investigated whether sympatho-adrenal overactivation evokes coronary vascular dysfunction when a high salt intake is combined with insulin resistance in male Goto–Kakizaki (GK) and Wistar rats treated with two different classes of β-blocker or vehicle, utilising synchrotron-based microangiography in vivo. Further, we examined if chronic carvedilol (CAR) treatment preserves nitric oxide (NO)-mediated coronary dilation more than metoprolol (MET). A high salt diet (6% NaCl w/w) exacerbated coronary microvessel endothelial dysfunction and NO-resistance in vehicle-treated GK rats while Wistar rats showed modest impairment. Microvascular dysfunction was associated with elevated expression of myocardial endothelin, inducible NO synthase (NOS) protein and 3-nitrotyrosine (3-NT). Both CAR and MET reduced basal coronary perfusion but restored microvessel endothelium-dependent and -independent dilation indicating a role for sympatho-adrenal overactivation in vehicle-treated rats. While MET treatment reduced myocardial nitrates, only MET treatment completely restored microvessel dilation to dobutamine (DOB) stimulation in the absence of NO and prostanoids (combined inhibition), indicating that MET restored the coronary flow reserve attributable to endothelium-derived hyperpolarisation (EDH). In conclusion, sympatho-adrenal overactivation caused by high salt intake and insulin resistance evoked coronary microvessel endothelial dysfunction and diminished NO sensitivity, which were restored by MET and CAR treatment in spite of ongoing inflammation and oxidative-nitrosative stress presumably caused by uninhibited renin–angiotensin–aldosterone system (RAAS) overactivation.
Experimental data using candesartan and captopril indicate no double-edged sword effect in COVID-19
Authors: Pedrosa Maria A. , Valenzuela Rita , Garrido-Gil Pablo , Labandeira Carmen M. , Navarro Gemma , Franco Rafael , Labandeira-Garcia Jose L. , Rodriguez-Perez Ana I. 
Published: January 2021

Abstract
The key link between renin–angiotensin system (RAS) and COVID-19 is ACE2 (angiotensin-converting enzyme 2), which acts as a double-edged sword, because ACE2 increases the tissue anti-inflammatory response but it is also the entry receptor for the virus. There is an important controversy on several drugs that regulate RAS activity and possibly ACE2, and are widely used, particularly by patients most vulnerable to severe COVID-19. In the lung of healthy rats, we observed that candesartan (an angiotensin type-1, AT1, receptor blocker; ARB) and captopril (an ACE inhibitor; ACEI) up-regulated expression of tissue ACE2 and RAS anti-inflammatory axis receptors (AT2 and Mas receptors). This effect was particularly pronounced in rats with metabolic syndrome (obesity, increased blood pressure and hyperglycemia) and aged rats. Treatment of cultures of human type-II pneumocytes with candesartan or captopril induced up-regulation of ACE2 expression in cells. Treatment with viral spike protein induced a decrease in full-length (i.e. transmembrane) ACE2, an increase in levels of a short intracellular ACE2 polypeptide and an increase in ADAM17 activity in cells, together with an increase in levels of soluble ACE2 and major proinflammatory cytokines in the culture medium. Spike protein-induced changes and levels of spike protein internalization in cells were inhibited by pretreatment with the above-mentioned drugs. The results suggest that these drugs increase ACE2 levels and promote the anti-inflammatory RAS axis in the lung. Furthermore, possible up-regulation of viral entry by the drug-induced increase in expression of transmembrane ACE2 is counteracted by additional mechanisms, particularly by drug-induced inhibition of ADAM17 activity.
Online multi‐parameter estimation of permanent magnet synchronous machine with step‐pulse injection
Authors: Wang Peng , Lin Keman , Lin Mingyao , Yang Anchen , Fu Fangyuan , Ai Jian 
Published: January 2021

AbstractOnline estimation of the machine parameters is essential to fault diagnosis and high‐performance control of permanent magnet synchronous machine (PMSM). The signal injection is an effective way to estimate machine parameters. However, the inductance variation caused by signal injection will result in difficulties for the estimated parameters to converge. At the same time, online parameters estimation brings heavy burden to the operation of control system. To solve these two problems, optimized inductance model is built with the step‐pulse injection to improve the accuracy of estimation. Compared with the existing method, the step‐by‐step parameter estimation method is adopted and orders of feedback matrix are reduced, which improves the computation efficiency. The forgetting factor recursive least square (FFRLS) algorithm is adopted to estimate stator resistance, rotor flux linkage and d‐, q‐axes inductances without acquiring any nominal parameter. The minimum amplitude and appropriate frequency of step‐pulse are determined by the parameter error and convergence analysis. The effectiveness of the proposed method is verified via a 1.5 kW PMSM drive platform.
Design of coaxial magnetic gear utilising a novel permanent magnet Halbach array structure
Authors: Mafi Hanieh , Afjei Ebrahim , Ghaheri Aghil 
Published: January 2021

AbstractMechanical gears are constrained due to wear and tear and call for lubrication. A magnetic gear, utilising permanent magnet (PM) arrays, facilitates the mechanical gear roles. It can withstand high‐speeds and large loads with zero friction. The magnetic gear is more efficacious on account of the least noise, performance, overload protection, and physical isolation between parts than conventional mechanical gears. The quantity of PMs in magnetic structures plays a principal role in its total price, which necessitates optimal arrangements for PMs. Halbach array provides a bigger torque density according to its one‐sided flux. In this research, proposing a novel Halbach array structure, leads to intensification in the one‐sided flux in a much sinusoidally waveform that consequently increases the magnetic torque. These all lead to gain higher torques in constant volumes of magnets. Besides, the magnetic torque ripple and the modulators’ losses are decremented. The new model is based on the variation of the magnetisation angles of the adjacent permanent magnet blocks, in the array. Various states of the magnetisation angles in the array are optimised based on a heuristic method. This is studied in the whole trigonometric range for magnetisation angles characteristics. The prototype is fabricated based on the optimised magnetic gear design and complies with the results.
Comparison of rare‐earth and hybrid‐magnet mover configurations for a permanent magnet synchronous linear motor
Authors: Liu Xiaomei , Yu Haitao , Gerada David , Xu Zeyuan , Qiu Hongbo , Jia Wanying , Yang Cunxiang 
Published: January 2021

AbstractForce ripple and cost reduction are two of the main challenges in optimising the design and increasing the market uptake of permanent magnet synchronous linear motors (PMSLM). Two mover configurations are compared in depth; one made entirely from rare‐earth materials while another consisting of a hybrid (rare‐earth/ferrite) magnet layout. First, the rare‐earth PMSLM is optimised and designed. Based on the same design and simulation methods, a hybrid PM materials with structure PMSLM is then proposed, optimised and designed using NdFeB at the centre pole‐section and ferrite at the edges. The two configurations of the PMSLM and their relative merits/demerits are compared using the simulation results of the flux density distribution in the air gap, back electromotive force (EMF), and cogging force. The hybrid‐magnet structure PMLSM has a better magnetic performance, and the force ripple is reduced by around 1%. Furthermore, the magnet material cost of the hybrid‐magnet PMLSM is reduced by nearly 25% compared with the original PMLSM. Finally, a prototype of the rare‐earth and hybrid‐magnet PMSLM is manufactured and tested to validate the modelling techniques and the results.
A fast level set image segmentation driven by a new region descriptor
Authors: Birane Abdelkader , Hamami Latifa 
Published: January 2021

AbstractIn order to deal with the intensities inhomogeneities and to overcome the effect of different types of noise in the image segmentation process, we have formulated a new level set function to implement a fast and robust active contour model. The proposed model was formulated by combining the SBGFRLS model and Legendre polynomials. With the aim of ensuring the segmentation accuracy and for dealing in the best way with the presence of noises and inhomogenous distribution of intensity, we define a local region descriptor for image intensities based on the Legendre polynomial. Instead of using the average intensity of the region, we regularised our level set function using a Gaussian filtering process. Experimental results on challenging images demonstrate the efficiency, robustness and the low cost and computational time of our model against the well‐known active contour models.
Colour image segmentation based on a convex K‐means approach
Authors: Wu Tingting , Gu Xiaoyu , Shao Jinbo , Zhou Ruoxuan , Li Zhi 
Published: January 2021

AbstractImage segmentation is a fundamental and challenging task in image processing and computer vision. The colour image segmentation is attracting more attention as the colour image provides more information than the grey image. A variational model based on a convex K‐means approach to segment colour images is proposed. The proposed variational method uses a combination of l1 and l2 regularizers to maintain edge information of objects in images while overcoming the staircase effect. Meanwhile, our one‐stage strategy is an improved version based on the smoothing and thresholding strategy, which contributes to improving the accuracy of segmentation. The proposed method performs the following steps. First, the colour set which can be determined by human or the K‐means method is specified. Second, a variational model to obtain the most appropriate colour for each pixel from the colour set via convex relaxation and lifting is used. The Chambolle–Pock algorithm and simplex projection are applied to solve the variational model effectively. Experimental results and comparison analysis demonstrate the effectiveness and robustness of the method.
General polynomial chaos‐based expansion finite‐difference time‐domain method for analysing electromagnetic wave propagation in random dispersive media
Authors: Liu Jiangfan , Li Huiping , Xi Xiaoli 
Published: January 2021

AbstractA new approach for using polynomial chaos‐based expansion finite‐difference time‐domain (PCE‐FDTD) is presented to calculate the uncertainty of electromagnetic wave propagation in dispersive materials. Based on the bilinear transform method, this approach performs polynomial expansion on random electromagnetic fields by PCE‐FDTD method. The proposed algorithm has a simple formulation and is very easy to extend to isotropic dispersive material. It has a general form for different types of random dispersive materials and can efficiently calculate the mean value and the SD of electromagnetic field components in a single run. Two examples of different dispersive media with two random variables are listed to show the generality of the algorithm, and a radar cross‐section of a perfectly conducting cylinder coated by a layer of random plasma is illustrated as an example to show the practicability of the approach. The results are validated by comparing it with the Monte Carlo method.
Symptomkontrolle bei Herzinsuffizienzpatienten – was tun bei abfallender GFR und bei Hyperkaliämie?
Authors: Brandenburg Vincent , Bauersachs Johann , Böhm Michael , Fliser Danilo , Frantz Stefan , Frey Norbert , Hasenfuß Gerd , Kielstein Jan T. 
Published: January 2021

ZusammenfassungBei Patienten mit Herzinsuffizienz und reduzierter Ejektionsfraktion wird durch eine optimierte medikamentöse Therapie sowohl die Symptomkontrolle verbessert als auch die Mortalität gesenkt. Eckpfeiler der Herzinsuffizienztherapie sind dabei Medikamente mit Einfluss auf das Renin-Angiotensin-Aldosteron-System, sogenannte RAAS-Inhibitoren. Dieser Artikel stellt einen kardiologisch-nephrologischen Konsens zur praxisorientierten Hilfestellung bei abnehmender glomerulärer Filtrationsrate oder Anstieg des Serum-Kaliumspiegels vor. Dies sind die 2 häufigsten Gründe für eine Dosisreduktion oder das Absetzen von prognoseverbessernden Medikamenten bei Herzinsuffizienzpatienten.
Permanent External Biliary Catheter: A Difficult Problem Managed by Rescue Technique of Hepatico-cholecysto-gastrostomy
Authors: Singla Vikas , Yadav Ajit Kumar , Arora Anil , Gupta Arun 
Published: January 2021

AbstractPercutaneous biliary drainage is commonly performed procedure after failure of ERCP in patients with biliary obstruction. Failure to internalization can lead to permanent external catheter. In the present case, problem of external biliary catheter was solved with hepaticocholecystogastrostomy. Guidewire from the external drain site could not be passed across the stricture, instead it was entering in the gall bladder. This was used as an opportunity to internalize the catheter. First EUS guided cholecystogastrostomy was performed, followed by placement of stent between right biliary system and the stomach, through the cholecystogastrostomy stent. This led to drainage of right biliary system into the stomach, and the external catheter could be removed.