bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of adult male horn developmental phenotypes and character displacement in Xylotrupes beetles (Scarabaeidae)
Authors: Huang Jen‐Pan , Morgan Brett
Published: March 2021

Character displacement that leads to divergent phenotypes between sympatric species has been hypothesized to facilitate coexistence and promote the accumulation of biodiversity. However, there are alternative evolutionary mechanisms that may also lead to the evolution of phenotypic divergence between sympatric species; one of the mechanisms is evolutionary contingency. We studied the evolution of the presence and absence of a major male horn phenotype, which may have ecological implications for promoting coexistence between sympatric beetles, across geographic populations from different Xylotrupes beetles. By using a previously published phylogeny with 80 Xylotrupes taxa, we estimated the transition rates between the two phenotypic states (i.e., presence vs. absence of a major male phenotype). Based on the estimated transition rates, we then simulated possible phenotypic outcomes between sympatric species. We found that sympatric species were equally likely to evolve the same versus distinct phenotypic states based on the estimated transition rates given the phylogeny. The empirically observed number of sympatric species showing different phenotypic states can be explained by evolutionary contingency alone. We discussed the importance of applying phylogenetic comparative methods when studying phenotypic evolution and more generally to investigate the effect of stochastic processes before making deterministic inferences.
Predicting the potential distribution and forest impact of the invasive species Cydalima perspectalis in Europe
Authors: Canelles Quim , Bassols Emili , Vayreda Jordi , Brotons Lluís
Published: March 2021

Invasive species have considerably increased in recent decades due to direct and indirect effects of ever‐increasing international trade rates and new climate conditions derived from global change. We need to better understand how the dynamics of early species invasions develop and how these result in impacts on the invaded ecosystems. Here we studied the distribution and severe defoliation processes of the box tree moth (Cydalima perspectalis W.), a tree defoliator insect native to Asia and invasive in Europe since 2007, through the combination of species distribution models based on climate and landscape composition information. The results showed that the combination of data from the native and the invaded areas was the most effective methodology for the appropriate invasive species modeling. The species was not influenced by overall landscape factors, but only by the presence of its host plant, dispersal capacity, and climate suitability. Such climate suitability was described by low precipitation seasonality and minimum annual temperatures around 0°C, defining a continentality effect throughout the territory. We emphasize the need of studying distribution and severe defoliation processes separately because we identified that climate suitability was slightly involved in limiting species spread processes but strongly constrained ecosystem impact in terms of defoliation before the species reaches equilibrium with the new environment. New studies on habitat recovery after disturbance, ecological consequences of such impact, and community dynamics in a context of climate change are required for a better understanding of this invasive species.
Effects of different exercise modalities on cardiac dysfunction in heart failure with preserved ejection fraction
Authors: Bode David , Rolim Natale P.L. , Guthof Tim , Hegemann Niklas , Wakula Paulina , Primessnig Uwe , Berre Anne Marie Ormbostad , Adams Volker , Wisløff Ulrik , Pieske Burkert M. , Heinzel Frank R. , Hohendanner Felix ,   OptimEx Study Group
Published: March 2021

Aims

Heart failure with preserved ejection fraction (HFpEF) is an increasingly prevalent disease. Physical exercise has been shown to alter disease progression in HFpEF. We examined cardiomyocyte Ca2+ homeostasis and left ventricular function in a metabolic HFpEF model in sedentary and trained rats following 8 weeks of moderate‐intensity continuous training (MICT) or high‐intensity interval training (HIIT).

Methods and results

Left ventricular in vivo function (echocardiography) and cardiomyocyte Ca2+ transients (CaTs) (Fluo‐4, confocal) were compared in ZSF‐1 obese (metabolic syndrome, HFpEF) and ZSF‐1 lean (control) 21‐ and 28‐week‐old rats. At 21 weeks, cardiomyocytes from HFpEF rats showed prolonged Ca2+ reuptake in cytosolic and nuclear CaTs and impaired Ca2+ release kinetics in nuclear CaTs. At 28 weeks, HFpEF cardiomyocytes had depressed CaT amplitudes, decreased sarcoplasmic reticulum (SR) Ca2+ content, increased SR Ca2+ leak, and elevated diastolic [Ca2+] following increased pacing rate (5 Hz). In trained HFpEF rats (HIIT or MICT), cardiomyocyte SR Ca2+ leak was significantly reduced. While HIIT had no effects on the CaTs (1–5 Hz), MICT accelerated early Ca2+ release, reduced the amplitude, and prolonged the CaT without increasing diastolic [Ca2+] or cytosolic Ca2+ load at basal or increased pacing rate (1–5 Hz). MICT lowered pro‐arrhythmogenic Ca2+ sparks and attenuated Ca2+‐wave propagation in cardiomyocytes. MICT was associated with increased stroke volume in HFpEF.

Conclusions

In this metabolic rat model of HFpEF at an advanced stage, Ca2+ release was impaired under baseline conditions. HIIT and MICT differentially affected Ca2+ homeostasis with positive effects of MICT on stroke volume, end‐diastolic volume, and cellular arrhythmogenicity.
Layered Arrangement of 1D Wavy Chains in the Lead‐Free Hybrid Perovskite (PyrCO2H)2BiI5: Structural Investigations and Properties
Authors: Skorokhod Alla , Hleli Feten , Hajlaoui Fadhel , Karoui Karim , Allain Magali , Zouari Nabil , Mercier Nicolas
Published: March 2021

Lead free organic‐inorganic hybrid perovskites have attracted increasing attention because of their variety of applications such as photovoltaics or lighting. Here, we reported a new iodobismuthate organic‐inorganic perovskite (PyrCO2H)2BiI5 where PyrCO2H+ is the 4‐carboxy‐1‐methylpyridinium. In the room temperature orthorhombic phase, the one‐dimensional (1D) inorganic framework which consists of cis‐connected corner‐sharing BiI6 octahedra, exhibits a sinusoidal deformation along the chain axis, while a regular chain leading to a sub‐cell is found in the high temperature phase (T>390 K). An original structural feature is the relative position of consecutive 1D chains in planes leading to a layered character of this organic‐inorganic compound. The electrical properties as function frequencies and temperatures have been studied in particular allowing the extraction of Rg and further the calculation of σg=f(T). Interestingly, a change of activation energy is detected at the phase transition temperature (390 K). The higher value of activation energy above 390 K can be attributed to change of the conduction mechanism involving ionic conduction.
Syntheses, Molecular Structures, and Countercation‐Induced Structural Transformation of Monomeric α‐Keggin‐Type Polyoxotungstate‐Coordinated Mono‐ and Dipalladium(II) Complexes
Authors: Kato Chika Nozaki , Nakahira Ippo , Kasai Ryota , Mori Shigeki
Published: March 2021

Monomeric α‐Keggin‐type polyoxotungstate‐coordinated mono‐ and di‐palladium(II) complexes, i. e., Cs5[α‐PW11O39{PdII(Me2ppz)}] ⋅ 5H2O (Cs‐1) (Me2ppz=N,N’‐dimethylpiperazine), [(CH3)4N]4H[α‐PW11O39{PdII(Me2ppz)}] ⋅ 8H2O (TMA‐1), and Cs2.5H0.5[α‐PW11O39{PdII(en)}2] ⋅ 7H2O (en=ethylenediamine) (Cs‐2), were synthesized by 1 : 1 or 1 : 2 stoichiometric reactions of mono‐lacunary α‐Keggin polyoxotungstate [α‐PW11O39]7− with PdCl2(Me2ppz) and PdCl2(en) in aqueous solution. Subsequent purification from water afforded these compounds as analytically pure homogeneous yellow precipitates. Single‐crystal X‐ray structural analysis of Cs‐1 revealed that a palladium(II) moiety, i. e., [Pd(Me2ppz)]2+, was coordinated to two oxygen atoms in the mono‐vacant site of [PW11O39]7− with an asymmetric configuration, resulting in an overall C1 symmetry. With regard to the crystal structure of Cs‐2, two palladium species of the [Pd(en)]2+ type were coordinated to two oxygen atoms in the mono‐vacant site with symmetric configuration, resulting in an overall Cs symmetry. A unique structural transformation of the mono‐lacunary α‐Keggin structure of Cs‐1 to the di‐lacunary γ‐Keggin polyoxotungstate Cs7[γ‐PW10O36] was observed upon the addition of cesium chloride.
The Reactivity of Multidentate Schiff Base Ligands Derived from Bi‐ and Terphenyl Polyamines towards M(II) (M=Ni, Cu, Zn, Cd) and M(III) (M=Co, Y, Lu)
Authors: Hylland Knut Tormodssønn , Gerz Isabelle , Wragg David S. , Øien‐Ødegaard Sigurd , Tilset Mats
Published: March 2021

Multidentate Schiff base ligands derived from a selection of biphenyl‐ and terphenyl polyamines were synthesized, and their reactivity towards divalent (Ni, Cu, Zn, Cd) and trivalent (Co, Y, Lu) metals was studied by single‐crystal X‐ray diffraction analysis, NMR spectroscopy, and UV/Vis spectroscopy for the Cu(II) complexes. Large variations in the resulting complexes were observed based on the relative position of the amine substituents in the parent triamines, as well as the electronic properties of the Schiff base ligand itself. Most notably, Schiff base ligands derived from a m‐terphenyl‐2,2’,2’’‐triamine were found to coordinate in a tetradentate, pentadentate or hexadentate fashion, depending on the size and the valency of the corresponding metal center.
The relationship between economic growth, renewable and nonrenewable energy use and CO2 emissions: empirical evidences for Brazil
Authors: Amarante José Carlos Araújo , Besarria Cássio da Nóbrega , Souza Helson Gomes de , dos Anjos Junior Otoniel Rodrigues
Published: March 2021

This article examined the causal relationship between economic growth, carbon dioxide (), and renewable and nonrenewable energy use for the 27 Brazilian states from 1997 to 2016. In order to achieve this objective, the system‐generalized method of moment was applied together with the autoregressive vector model for panel data. Estimates of the multivariate model established important relationships to promote public policies. Empirical results show that there is a two‐way relationship between economic growth and emissions. While growth negatively causes emissions, the impact of emissions on economic growth is positive. Additionally, the degree of using nonrenewable energy has a positive effect on economic growth and emissions. On the other hand, renewable energy use positively affects economic growth and negatively affects emissions. Also, economic growth positively causes the use of energies derived from renewable and nonrenewable sources. Finally, as expected, emissions do not affect energy use. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.
Assessment of CO2 capture technologies for CO2 utilization in enhanced oil recovery
Authors: Ogidiama Oghare Victor , Shamim Tariq
Published: March 2021

CO2 capture is considered to be a viable means of reducing the harmful environmental impacts of the fossil fuel usage. The net cost of CO2 capture can be reduced and, consequently, the adoption of CO2 capture methods can be enhanced by developing revenue streams for the captured CO2. Enhanced oil recovery (EOR), which is the process of withdrawing crude from oil reservoirs after primary and secondary withdrawal, is viewed as an attractive means of CO2 utilization. The EOR process has the capacity to take large volumes of CO2 captured from power plants and use them for the production of incremental oil. The process which is known as CO2‐EOR has synergistic benefits for the oil and gas and power generation industries. Different CO2 capture technologies are currently being used and their suitability of supplying captured CO2 for utilization in EOR may not be similar. This study analyzes the ease of utilization of CO2 captured from power plants in EOR applications. The analysis is done by comparing different capture technologies in terms of cost and purity of CO2 captured and their suitability of integration with the EOR. The results determine that the post‐combustion CO2 capture is the most EOR friendly technique in terms of CO2 stream purity, while the chemical looping combustion (CLC) is the most EOR amenable in terms of the capture cost. The results show that the CO2 capture efforts from power plants using CLC can be fully covered by additional oil revenue at oil prices above $27.9 per barrel ($175.5/m3). © 2021 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons, Ltd.
Nitrogen source impacts Rhizoctonia leaf and sheath spot severity in ultradwarf bermudagrass
Authors: Dant L. A. , Martin S. B. , Kerns J. P. , McCarty L. B.
Published: March 2021

The disease Rhizoctonia leaf and sheath spot (RLSS), caused by Rhizoctonia zeae Voorhees, is problematic in ultradwarf bermudagrass (UDBG) [Cynodon dactylon (L.) Pers. × C. transvaalensis (Burtt‐Davy)] putting greens. Typically, RLSS symptoms are most severe in late summer and appear as frog‐eye patches 10 to 40 cm in diameter. In UDBG, RLSS is often called “mini‐ring” because of the small brown rings that are produced when symptoms are prominent. The effect of N source and N rate on RLSS severity was investigated in 2016 and 2017. Nitrogen sources, ammonium sulfate (AMS) [(NH4)2SO4] and urea (CH4N2O) were applied weekly during the growing season at rates of 4.9, 9.8, and 14.7 kg N ha−1. The study was conducted on ‘P18’ (MiniVerde) and ‘TifEagle’ UDBG cultivars maintained as research putting greens at the Clemson University Pee Dee Research and Education Center in Florence, SC. For both cultivars and in both years, urea decreased RLSS severity when compared to AMS. In November of 2016, RLSS severity increased with increasing rates of AMS; however, a rate response was not evident in 2017. In November of 2016 and 2017, RLSS severity was 25 and 30% when AMS was applied at 14.7 kg N ha−1 wk−1 verses 3 and 1% for UDBG receiving applications of urea at that same rate. These studies demonstrate that utilizing urea as an N source, rather than AMS, is an effective strategy to manage RLSS in UDBG.
Phylogenetic evaluation of Bipolaris and Curvularia species collected from turfgrasses
Authors: Connally Andrea , Smith Damon , Marek Stephen , Wu Yanqi , Walker Nathan
Published: March 2021

The dothideomycete genera Bipolaris and Curvularia are important pathogens of grasses (Poaceae) and can associate with host tissues without disease symptoms. Species of both genera are responsible for leaf spot epidemics that commonly occur on turfgrass throughout the United States transition zone and southern regions. Recent species typifications with DNA sequences have made a broad examination of Bipolaris and Curvularia species obtained from turfgrass possible. Isolates for analysis were obtained from culture collections or isolated from symptomatic turfgrass samples. Phylogenies based on ITS, GPD, and TEF gene sequences were constructed using maximum likelihood and Bayesian analyses and used to determine intraspecific and intrageneric relationships among Bipolaris and Curvularia species isolated from turfgrasses. Similar to previous studies, Bipolaris and Curvularia species formed separate, well‐supported clades. Morphological identifications of genera and species based on published host‐based keys often disagreed with molecular groupings. For example, C. hawaiiensis (= B. hawaiiensis) could not be differentiated from B. cynodontis while C. australiensis (= B. australiensis) could not be differentiated from C. spicifera (= B. spicifera). Additionally, phylogenies suggest B. coffeana and B. cynodontis are synonymous. However, the number of pseudosepta per conidium was the only consistent morphological character. The delineation of species causing leaf spot diseases of warm‐season turfgrasses should improve disease management decisions and help identify potential pathogens in asymptomatic tissues.
Persistence and performance of spring‐flowering bulbs in warm‐ and cool‐season turfgrasses in a subtropical climate
Authors: Pennisi Svoboda V. , Waltz Freddie C. , Miller William B.
Published: March 2021

Performance of eight spring‐flowering bulbs, Chionodoxa sp. ‘Blue Giant’ (glory‐of‐the‐snow), Crocus tommasinianus ‘Ruby Giant’ (crocus), Crocus vernus ‘Remembrance’ (crocus), Narcissus ‘Ice Follies’, N. ‘Tete‐a‐Tete’, N. ‘Thalia’ (daffodil), Muscari sp. ‘Blue Magic’ (grape hyacinth), and Scilla sybirica (Siberian squill), was evaluated after planting into cool season tall fescue lawn [Lolium arundinaceum (Schreb.) Darbysh. (syn. Festuca arundinacea Schreb.)] ‘Lexington’ and warm‐season hybrid bermudagrass lawn [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] ‘Tift 94’ (TifSport®) and subjected to various mowing regimes. In the first year after planting, bulbs flowered over a three week period, with peak bloom from the last week of February until mid‐March. However, only daffodil Tete‐a‐Tete and crocus Ruby Giant exhibited satisfactory persistence (defined as >40% bulbs with flowers after two growing seasons), although daffodil Thalia showed satisfactory persistence in a hybrid bermudagrass lawn. Mowing treatment did not significantly affect total bloom count in the second year after planting. Based on our results, daffodil Ice Follies, Siberian squill, grape hyacinth, and glory‐of‐the‐snow were non‐persistent (defined as <10% bulbs with flowers after two growing seasons). The specially designed bulb planter used in this study did not appear to negatively impact turf health. This study demonstrated that warm‐season and cool‐season lawns could be successfully interplanted with spring‐flowering geophytes in a subtropical climate; however, species and cultivars selection is essential to ensure long‐term persistence and maximum aesthetic appearance.
Estimated energy use and greenhouse gas emissions associated with golf course turfgrass maintenance in the Northern USA
Authors: Bekken Michael A. H. , Soldat Douglas J.
Published: March 2021

Carbon sequestration in golf course soils has received some attention, but energy use and greenhouse gas (GHG) emissions from golf course turfgrass maintenance are poorly quantified. This study developed a model to estimate energy consumption and GHG emissions from golf turf maintenance and applied the model to 14 golf courses located in the northern USA over a 3‐yr period. Energy use and GHG emissions that result from golf course maintenance operations were divided into three scopes. Scope 1 consisted of onsite emissions (n = 14), Scope 2 consisted of offsite emissions (n = 7), and Scope 3 consisted of supply chain (upstream) emissions (n = 7). Scope 1 emissions primarily result from onsite fuel use, Scope 2 emissions primarily result from offsite electricity generation, and Scope 3 emissions primarily result from the production and transport of goods and materials (e.g., machines, fertilizers, pesticides) to the golf course. All scopes were combined to calculate total energy use and emissions (n = 4). Mean area‐normalized Scope 1 energy use was 24 GJ ha–1 yr–1, mean Scope 2 energy use was 7 GJ ha–1 yr–1, mean Scope 3 energy use was 40 GJ ha–1 yr–1 and the mean of all scopes was 72 GJ ha–1 yr–1. Mean area‐normalized Scope 1 emissions were 1,599 kg CO2e ha–1 yr–1, mean Scope 2 emissions were 1,012 kg CO2e ha–1 yr–1, mean Scope 3 emissions were 1,847 kg CO2e ha–1 yr–1 and the mean of all scopes was 4,277 kg CO2e ha–1 yr–1. Fuel and electricity use accounted for 63% of all GHG emissions. Electrifying golf course maintenance equipment and sourcing electricity generated from renewable sources are likely the most effective ways for golf course turfgrass maintenance emissions to be reduced.
Photoacoustic imaging of in vivo hemodynamic responses to sodium nitroprusside
Authors: Zhang Dong , Li Ran , Chen Maomao , Vu Tri , Sheng Huaxin , Yang Wei , Hoffmann Ulrike , Luo Jianwen , Yao Junjie
Published: March 2021

The in vivo hemodynamic impact of sodium nitroprusside (SNP), a widely used antihypertensive agent, has not been well studied. Here, we applied functional optical‐resolution photoacoustic microscopy (OR‐PAM) to study the hemodynamic responses to SNP in mice in vivo. As expected, after the application of SNP, the systemic blood pressure (BP) was reduced by 53%. The OR‐PAM results show that SNP induced an arterial vasodilation of 24% and 23% in the brain and skin, respectively. A weaker venous vasodilation of 9% and 5% was also observed in the brain and skin, respectively. The results show two different types of blood oxygenation response. In mice with decreased blood oxygenation, the arterial and venous oxygenation was respectively reduced by 6% and 13% in the brain, as well as by 7% and 18% in the skin. In mice with increased blood oxygenation, arterial and venous oxygenation was raised by 4% and 22% in the brain, as well as by 1% and 9% in the skin. We observed venous change clearly lagged the arterial change in the skin, but not in the brain. Our results collectively show a correlation among SNP induced changes in systemic BP, vessel size and blood oxygenation.
Mutational screening through comprehensive bioinformatics analysis to detect novel germline mutations in the APC gene in patients with familial adenomatous polyposis (FAP)
Authors: Ghadamyari Faranak , Heidari Mohammad Mehdi , Zeinali Sirous , Khatami Mehri , Merat Shahin , Bagherian Hamideh , Rejali Leili , Ghasemi Farzaneh
Published: March 2021

Background

Familial adenomatous polyposis (FAP) as a colon cancer predisposition syndrome is an autosomal‐dominant inherited condition and is diagnosed by the progress of hundreds or thousands of adenomatous colonic polyps in the colon. This study aims at the nature and effect of Adenomatous Polyposis Coli (APC) gene mutations in FAP tumorigenesis.

Methods

The genetic screening of 59 FAP Iranian patients in 10 families was performed by polymerase chain reactions and the direct sequencing of the entire coding exons of the APC gene. To do linkage haplotype analysis and multiplex PCR‐based microsatellite examination, six short tandem repeat loci were selected in this gene. To evaluate and predict the potentially deleterious effects, comprehensive bioinformatics pathogenicity assays were used.

Results

A total of 12 germline heterozygous and homozygous nucleotide variations were identified. They included two missense mutations, four nonsense mutations, which would lead to the truncated and nonfunctional protein products, four synonymous or silent variations, and two nucleotide deletions of 1 to 5 bp or frameshift mutations. In addition, three novel heterozygous nonsense mutations were found in exons 10, 14, and 15 of the gene. There was also p.Arg653Met as a novel heterozygote mutation in exon 14 of the gene.

Conclusions

Bioinformatics analysis and three‐dimensional structural modeling predicted that these missense and nonsense mutations generally are associated with the deleted or truncated domains of APC and have functional importance and mainly affected the APC protein. These findings may provide evidence for the progress of potential biomarkers and help to understand the role of the APC gene in FAP.
Nitazoxanide versus rifaximin in preventing the recurrence of hepatic encephalopathy: A randomized double‐blind controlled trial
Authors: Glal Khadija A. M. , Abd‐Elsalam Sherief M. , Mostafa Tarek M.
Published: March 2021

Background/Purpose

Hepatic encephalopathy (HE) is a neuropsychiatric complication of liver cirrhosis. HE is associated with poor survival and detrimental effects on quality of life (QOL). The drawbacks of the long‐term use of rifaximin in HE necessitates searching for alternative therapies. In this context, our study aimed at evaluating the safety and efficacy of nitazoxanide (NTZ) as compared to rifaximin (RFX) in preventing the recurrence of HE and assessing its impact on QOL.

Patients and Methods

This prospective, randomized, double‐blind controlled study included 60 patients who were randomly assigned to receive either rifaximin 550 mg twice daily (group 1; n = 30) or nitazoxanide 500 mg twice daily (group 2; n = 30) for 24 weeks. During the study period, the patients' neurological symptoms, mental status, and performance were monitored. The serum levels of HE triggers (ammonia, TNF‐α, and octopamine) were assessed. The patients' health‐related quality of life was also evaluated.

Results

Six months after treatment, patients on NTZ therapy showed a statistically significant improvement in CHESS score and mental status. NTZ provided 136 days of remission vs 67 days of remission for patients on RFX (P1 = .0001) and significant reduction in Child score (P1 = .018). Additionally, NTZ showed a statistically significant decrease in serum ammonia, TNF‐α, and octopamine levels as compared to rifaximin. Regarding QOL, NTZ group showed an improvement in total Chronic Liver Disease Questionnaire (CLDQ) score. Both groups experienced minor controllable side effects.

Conclusion

Nitazoxanide may represent a suitable and safe alternative therapy to rifaximin in preventing the recurrence of hepatic encephalopathy.
Efficacy and safety of the second‐generation cryoballoon ablation for the treatment of persistent atrial fibrillation in elderly patients
Authors: Vermeersch Gaëlle , Abugattas Juan‐Pablo , Varnavas Varnavas , De Cocker Jeroen , Schwagten Bruno , Sieira Juan , de Asmundis Carlo , Chierchia Gian‐Battista , De Greef Yves
Published: March 2021

Background

It is expected that ablation procedures will be increasingly offered to a more aged population affected with persistent AF (persAF); however, the clinical outcomes of ablation in this specific population are not well described. We aimed to analyze the efficacy and safety of CB‐A in this group of patients compared with a younger cohort.

Methods and results

Eighty‐three patients with (persAF) aged ≥75 years (group 1; mean age 78.2 ± 3.1 years) and 166 patients also affected with persAF aged <75 years (group 2; mean age 64.3 ± 6.6 years) were included in the study. The primary outcome was freedom from recurrent sustained (>30 seconds) atrial arrhythmias without anti‐arrhythmic medication after a blanking period of 3 months. At 2 years, clinical success was achieved in 108 out of 249 patients (43.4%). Median follow‐up was 24 months (IQR: 18.4‐25.5 months). Older patients suffered from more recurrences than those in the younger cohort ((53/83 patients, 63.9% vs 88/166 patients, 53.0%; P = .03). Thirty (12.0%) patients suffered a complication, but the incidence of complications was not different between both groups. The most frequent complication was transient phrenic nerve injury.

Conclusions

The global 2 years efficacy of CB‐A PVI in persAF is 43.4%. A lower success rate is achieved in the older patients (36.1%) compared to the younger age group (47.0%). However, the complication rate was not different between age groups.
Observed changes in air temperature and precipitation extremes over Brazil
Authors: Regoto Pedro , Dereczynski Claudine , Chou Sin Chan , Bazzanela Anna Carolina
Published: March 2021

We analyse seasonal and annual trends of extreme indices of air temperature and precipitation over Brazil during the period 1961–2018. The main goal is to investigate whether the climate is changing and if so, to explore if there is any marked seasonality in such changes. The daily observed datasets of maximum and minimum temperatures, and precipitation, are provided by the Brazilian National Institute of Meteorology and National Water Agency. We use the Sen Curvature and Mann‐Kendall statistical tests to compute the magnitudes and to evaluate the statistical significance of climate extremes trends, respectively. The results show that the warm extremes frequency of occurrence is increasing significantly while the opposite occurs for cold extremes, which reveals a very consistent and widespread warming over Brazil. The highest increases in warm extremes occur during austral spring and summer while for the cold extremes the greatest decreases are observed during austral winter. Unlike temperature, precipitation extremes show heterogeneous signals for most of the country. In Northeast Brazil, there are changes towards a drier climate, especially in summer and autumn. In the Southern region, the climate is becoming wetter, with a reduction in consecutive dry days, especially in spring. For the other regions, there is no strong clear change sign, but both positive and negative precipitation extreme trends, without statistical significance (mostly in Southeast Region).
Determinants of nonperforming loans after recapitalization in the Nigerian banking industry: Does efficiency matter?
Authors: Bolarinwa Segun Thompson , Akinyele Olawale , Vo Xuan Vinh
Published: March 2021

We examine the intertemporal relationship between nonperforming loans, efficiency and bank recapitalization in the Nigerian banking industry between 2011 and 2018. Using system generalized method of moments (SGMM) and stochastic frontier analysis (SFA), we document the importance of bank efficiency for addressing escalating nonperforming loans in the industry after recapitalization policies and the channels pass‐through between efficiency and the nonperforming loans‐recapitalization nexus. Our results validate the roles of firm‐level and macroeconomic variables: bank size, efficiency, profitability, capitalization, economic growth, inflation, and money supply for addressing nonperforming loans. Also, efficiency passes through recapitalization and bank size to address nonperforming loans. We recommend prudential policies for managerial and profit efficiency and lend supports for CBN's new round of recapitalization policy to address escalating nonperforming loans in the industry.
A Bayesian approach to diffusional kurtosis imaging
Authors: Umezawa Eizou , Ishihara Daichi , Kato Ryoichi
Published: March 2021

Purpose

Diffusional kurtosis metrics show high performance for detecting pathological changes and are therefore expected to be disease biomarkers. Kurtosis maps, however, tend to be noisy. The maps’ visual quality is crucial for disease diagnosis, even when kurtosis is being used quantitatively. A Bayesian method was proposed to curtail the large statistical error inherent in kurtosis estimation while maintaining potential application to biomarkers.

Theory

Gaussian priors are determined from first‐step estimations implemented using the least‐square method (LSM). The likelihood‐function variance is determined from the residuals of the estimation. Although the proposed approach is similar to a regularized LSM, regularization parameters do not have to be artificially adjusted. An appropriate balance between denoising and preventing false shrinkages of metric dispersions is automatically achieved.

Methods

Map qualities achieved using the conventional and proposed methods were compared. The receiver‐operating characteristic analysis was performed for glioma‐grade differentiation using simulated low‐ and high‐grade glioma DWI datasets. Noninferiority of the proposed method was tested for areas under the curves (AUCs).

Results

The noisier the conventional maps, the better the proposed Bayesian method improved them. Noninferiority of the proposed method was confirmed by AUC tests for all kurtosis‐related metrics. Superiority of the proposed method was also established for several metrics.

Conclusions

The proposed approach improved noisy kurtosis maps while maintaining their performances as biomarkers without increasing data acquisition requirements or arbitrarily choosing LSM regularization parameters. This approach may enable the use of higher‐order terms in diffusional kurtosis imaging (DKI) fitting functions by suppressing overfitting, thereby improving the DKI‐estimation accuracy.
Synchrotron X‐ray micro‐CT as a validation dataset for diffusion MRI in whole mouse brain
Authors: Trinkle Scott , Foxley Sean , Kasthuri Narayanan , La Rivière Patrick
Published: March 2021

Purpose

To introduce synchrotron X‐ray microcomputed tomography (microCT) and demonstrate its use as a natively isotropic, nondestructive, 3D validation modality for diffusion MRI in whole, fixed mouse brain.

Methods

Postmortem diffusion MRI and microCT data were acquired of the same whole mouse brain. Diffusion data were processed using constrained spherical deconvolution. Synchrotron data were acquired at an isotropic voxel size of 1.17 μm. Structure tensor analysis was used to calculate fiber orientation distribution functions from the microCT data. A pipeline was developed to spatially register the 2 datasets in order to perform qualitative comparisons of fiber geometries represented by fiber orientation distribution functions. Fiber orientations from both modalities were used to perform whole‐brain deterministic tractography to demonstrate validation of long‐range white matter pathways.

Results

Fiber orientation distribution functions were able to be extracted throughout the entire microCT dataset, with spatial registration to diffusion MRI simplified due to the whole brain extent of the microCT data. Fiber orientations and tract pathways showed good agreement between modalities.

Conclusion

Synchrotron microCT is a potentially valuable new tool for future multi‐scale diffusion MRI validation studies, providing comparable value to optical histology validation methods while addressing some key limitations in data acquisition and ease of processing.
Analysis and mitigation of noise in simultaneous transmission and reception in MRI
Authors: Tasdelen Bilal , Sadeghi‐Tarakameh Alireza , Yilmaz Ugur , Atalar Ergin
Published: March 2021

Purpose

In simultaneous transmission and reception (STAR) MRI, along with the coupling of the excitation pulse to the received signal, noise, and undesired distortions (spurs) coming from the transmit chain also leak into the acquired signal and degrade image quality. Here, properties of this coupled noise and its relationship with the transmit amplifier gain, transmit chain noise density, isolation performance, and imaging bandwidth are analyzed. It is demonstrated that by utilizing a recently proposed STAR technique, the transmit noise can be reduced. The importance of achieving high isolation and careful selection of the corresponding parameters are demonstrated.

Theory and Methods

A cancellation algorithm, together with a vector modulator, is used for transmit‐receive isolation. The scanner is modeled as a pipeline of blocks to demonstrate the noise contribution from each block. With higher isolation, coupled transmit noise can be reduced to the point that the dominant noise source becomes acquisition noise, as in the case for pulsed MRI. Amplifiers with different gain and noise properties are used in the experiments to verify the derived noise‐transmit parameter relation.

Results

With the proposed technique, more than 80 dB isolation in the analog domain is achieved. The leakage noise and the spurs coupled from the transmit chain, are reduced. It is shown that the transmit gain plays the most critical role in determining sufficient isolation, whereas the amplifier noise figure does not contribute as much.

Conclusion

The transmit noise and the spurs in STAR imaging are analyzed and mitigated by using a vector modulator.
Incomplete inverse matrices
Authors: Filelis‐Papadopoulos Christos K.
Published: March 2021

The solution of large sparse linear systems is required in many scientific fields such as computational fluid dynamics, computational electromagnetism, computational finance, etc. The computation of the solution of these systems is performed with preconditioned iterative methods, which rely on effective preconditioning schemes. A new class of approximate inverses is proposed, namely incomplete inverse matrices, which are computed using a recursive Schur complement‐based approach. This class of approximate inverses is based on a priori knowledge of a sparsity pattern. In order to have finer control over the density of the proposed approximate inverse, especially in the case of three‐dimensional problems, on‐the‐fly filtration is used, resulting in substantial reduction in the number of nonzero elements. Implementation details and analysis for computing the proposed scheme are given. Numerical results depicting the effectiveness and applicability of the proposed scheme are also provided.
Inhibition of guanosine monophosphate synthetase (GMPS) blocks glutamine metabolism and prostate cancer growth
Authors: Wang Qian , Guan Yi Fang , Hancock Sarah E , Wahi Kanu , van Geldermalsen Michelle , Zhang Blake K , Pang Angel , Nagarajah Rajini , Mak Blossom , Freidman Natasha , Horvath Lisa G , Turner Nigel , Holst Jeff
Published: March 2021

Glutamine is a critical nutrient in cancer; however, its contribution to purine metabolism in prostate cancer has not previously been determined. Guanosine monophosphate synthetase (GMPS) acts in the de novo purine biosynthesis pathway, utilizing a glutamine amide to synthesize the guanine nucleotide. This study demonstrates that GMPS mRNA expression correlates with Gleason score in prostate cancer samples, while high GMPS expression was associated with decreased rates of overall and disease/progression‐free survival. Pharmacological inhibition or knockdown of GMPS significantly decreased cell growth in both LNCaP and PC‐3 prostate cancer cells. We utilized [15N‐(amide)]glutamine and [U‐13C5]glutamine metabolomics to dissect the pathways involved and despite similar growth inhibition by GMPS knockdown, we show unique metabolic effects across each cell line. Using a PC‐3 xenograft mouse model, tumor growth was also significantly decreased after GMPS knockdown, highlighting the importance of glutamine metabolism and providing support for GMPS as a therapeutic target in prostate cancer. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Eco‐friendly polymer composites: A review of suitable methods for waste management
Authors: Cabrera Flávio C.
Published: March 2021

The amount of residues generated by agriculture, industrial, or urban activities continuously increases and, consequently, demands several methods for their correct management. The incorrect disposal can cause, in specific cases, environmental contamination by heavy metals or leaching as well as promote the spread of diseases as insect proliferation. Commonly, landfilling, incinerating, composting, or energy/fuel generation can control the disposal or reuse of residues. Among the methods for the reuse of wastes, the incorporation of residues as fillers in polymer composites has emerged as a distinct field. Some composites can potentially mitigate leaching compounds or improve mechanical, thermal, and acoustic properties. However, these improvements are a challenge to promote the use of waste fillers. Thus, this study aims to provide a state of view regarding a variety of wastes used as fillers in polymer composites and different methods to reach mechanical reinforcement as well as improve thermal conductivity and acoustic attenuation for future researches.
High‐performance and cost‐effective melt blended poly(ether ether ketone)/expanded graphite composites for mass production of antistatic materials
Authors: Mokhtari Mozaffar , Archer Edward , Bloomfield Noel , Harkin‐Jones Eileen , McIlhagger Alistair
Published: March 2021

In this study unfunctionalized expanded graphite (EG) was incorporated into poly(ether ether ketone) (PEEK) using twin‐screw extrusion and injection moulding to manufacture cost‐effective PEEK/EG composites for mass production of high‐performance antistatic materials. Direct current electrical conductivity, morphology, rheological and thermal properties of the composites were investigated. At an EG loading of 5 vol%, the electrical conductivity exhibited an abrupt increase to 1.45 × 10−5 S m−1 which was in the required range of electrical conductivity of antistatic materials. The frequency dependence of the storage modulus of the melt containing  2 vol% EG decreased significantly at low frequencies. Viscosity did not increase much with the addition of EG in comparison with other nanofillers such as carbon nanotubes. The crystallinity of PEEK increased to 41.11% from 35.87% upon addition of  3 vol% EG. EG improved the thermal stability of PEEK by an increase in the initiation temperature of its decomposition steps. © 2021 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.
A High‐Sensitivity Refractive Index Sensor Based on an External Gold Coating of a Square‐Lattice Photonic Crystal Fiber
Authors: Wang Yujun , Li Shuguang , Wang Mingyue
Published: March 2021

A high‐sensitivity square‐lattice photonic crystal fiber (PCF) refractive index (RI) sensor based on an external gold coating is proposed. This design eliminates the limitations of selective coating and liquid penetration in the micrometer holes, and avoids the side polishing of D‐type fibers. The effects of air hole diameter and gold film thickness on the sensing performance are studied in detail using the full vector finite element method (FV‐FEM). In addition, the sensing performance of the gold‐coated PCF under the optimized parameters is compared with that of PCF with the same air hole diameter and a gold grating. The results show that the proposed PCF has a higher structural tolerance to the air hole diameter, which improves the manufacturing feasibility. Moreover, the gold‐coated PCF has a maximum sensitivity of 31 000 nm RIU−1 and a resolution of 3.23 × 10−6 RIU in the RI measurement range of 1.34–1.49. The maximum sensitivity of the gold‐grating PCF with lower loss is 30 000 nm RIU−1 in the RI detection range of 1.38–1.46, and the resolution is 3.33 × 10−6 RIU. Low loss is beneficial for extending the length of the fiber, which is convenient for practical implementation. Thus, it has potential applications in biomolecular and biochemical analysis.
Phosphorous Diffusion Gettering of Trapping Centers in Upgraded Metallurgical‐Grade Solar Silicon
Authors: Catalán-Gómez Sergio , Dasilva-Villanueva Nerea , Fuertes Marrón David , del Cañizo Carlos
Published: March 2021

Experimental evidence indicating the beneficial impact of a phosphorous diffusion gettering (PDG) in the reduction of trapping centers is shown, as observed by means of inductively coupled photoconductance (PC) decay and lifetime measurements carried out on upgraded metallurgical‐grade silicon (UMG‐Si) wafers. The presence of trapping species dominating the long time range of the PC decay of UMG material (slow traps), which is effectively removed after a PDG conducted at 780 °C, is detected. Notwithstanding, a second trapping mechanism, characterized by a shorter time constant, still governs the response at very low injection levels after the gettering. Furthermore, the beneficial effect of the PDG is studied as a function of processing time, showing minority carrier bulk lifetime improvements up to 18‐fold, up to the range of 70 μs. Thereby, the way for developing gettering strategies capable of successfully removing trap centers and improving the bulk lifetime of unconventional Si material is paved.
Finite‐time fault‐tolerant output feedback attitude control of spacecraft formation with guaranteed performance
Authors: Gao Han , Xia Yuanqing , Zhang Jinhui , Cui Bing
Published: March 2021

This article examines the problem of finite‐time fault‐tolerant output feedback attitude control for spacecraft formation system with guaranteed performance, in the presence of uncertainties, external disturbances, actuator faults, and input saturation. First, a neural network (NN) based finite‐time observer is established for follower spacecraft to observe its angular velocity, where the NN is utilized to approximate the unknown uncertainties. Furthermore, based on the information from the angular velocity observer, backstepping procedure, and barrier Lyapunov function technique, a distributed finite‐time controller with only attitude measurement is proposed. Unlike the existing finite‐time control scheme, the tracking errors keep inside their predefined feasible regions with guaranteed transient and steady‐state performance. A theoretical proof shows that the finite‐time stability of the closed‐loop system can be achieved. Finally, numerical simulation results are presented to illustrate the effectiveness and fine performance of the proposed finite‐time observer and controller for the attitude control system.
Biologically Active Quinoline‐Hydrazone Conjugates as Potential Trypanosoma cruzi DHFR‐TS Inhibitors: Docking, Molecular Dynamics, MM/PBSA and Drug‐Likeness Studies
Authors: Yepes Andrés F. , Quintero‐Saumeth Jorge , Cardona‐Galeano Wilson
Published: March 2021

Chagas disease, is a chronic parasitic infection caused by protozoan parasites belonging to the genus Trypanosoma. New therapies for Chagas infections are urgently needed and represent a major challenge in medicinal chemistry. As part of these efforts, we recently designed and synthesized a series of molecular hybrids bearing quinoline and hydrazones moieties, with some of them displaying higher anti‐trypanosomal activities than benznidazole. Thus, the current work is focused on proposing a plausible action mechanism by which the most active compounds inhibited T. cruzi growth based on multilevel computational approaches. Docking showed that for the best binders there was a marked preference for binding to dihydrofolate reductase (DHFR) over cruzipain (around −9.0 kcal/mol). MD simulations not only validate the reliability of docking predictions, but showed that the ligand‐receptor complex was stable during the extended 50 ns simulations inside the active site (RMSD value of 1.96±0.34 Å). Furthermore, MM/PBSA studies also affirm the docking results. The MM/PBSA method revealed that most of the residues involved in the binding event are hydrophobic in nature, which are in accordance with those aminoacids essential in the DHFR function. Satisfactory pharmacokinetics profiles were also estimated for the top‐three active compounds. Finally, the results suggested that the active hybrids might act by inhibiting DHFR activity within T. cruzi, making them a privileged scaffold that can be used in future anti‐Chagas drug development.
A Novel Perovskite Electron–Ion Conductive Coating to Simultaneously Enhance Cycling Stability and Rate Capability of Li1.2Ni0.13Co0.13Mn0.54O2 Cathode Material for Lithium‐Ion Batteries
Authors: Gao Mingxi , Yan Chenhui , Shao Qinong , Chen Jian , Zhang Chenyang , Chen Gairong , Jiang Yinzhu , Zhu Tiejun , Sun Wenping , Liu Yongfeng , Gao Mingxia , Pan Hongge
Published: March 2021

Poor cycling stability and rate capability are two key issues needing to be solved for Li‐ and Mn‐rich oxide cathode material for lithium‐ion batteries (LIBs). Herein, a novel perovskite electron–ion mixed conductor Nd0.6Sr0.4CoO3 (NSCO) is used as the coating layer on Li1.2Ni0.13Co0.13Mn0.54O2 (LNCMO) to simultaneously enhance its cycling stability and rate capability. By coating 3 wt% NSCO, LNCMO–3NSCO exhibits an optimal cycling performance with a capacity retention of 99% at 0.1C (1C = 200 mA g−1) after 60 cycles, 91% at 1C after 300 cycles, and 54% at 20C after 1000 cycles, much better than 78%, 63%, and 3% of LNCMO, respectively. Even at a high charge and discharge rate of 50C, LNCMO–3NSCO exhibits a discharge capacity of 53 mAh g−1 and a mid‐point discharge voltage of 2.88 V, much higher than those of LNCMO (24 mA h g−1 and 2.40 V, respectively). Benefiting from the high electronic conductivity (1.46 S cm−1) and ionic conductivity (1.48 × 10−7 S cm−1), NSCO coating not only suppresses transition metals dissolution and structure transformation, but also significantly enhances electronic conductivity and Li+ diffusion coefficient of LNCMO by an order of magnitude.