bluuebunny/crossref_metadata_2025_split huggingface dataset:
Satellite observed vegetation dynamics and drivers in the Namib sand sea over the recent 20 years
Authors: Qiao Na , Wang Lixin 
Published: March 2022

AbstractMonitoring dryland vegetation trends and examining the drivers are of great importance to understand the dryland vegetation response to future climate changes. Recent findings through satellite data indicate that vegetation greenness has increased in several regions worldwide. These greening patterns are driven by human activities or combined human activities and environmental factors. However, the analyses of greenness trend for regions without direct human activities and shrub expansion in drylands are still lacking. To this end, this study investigates the vegetation trend across the Namib sand sea over March 2000 to December 2018 using monthly Normalized Difference Vegetation Index (NDVI) and examines several potential drivers including precipitation, temperature and atmospheric CO2 concentration. For the NDVI time series across the whole study region, a significant greening trend was found over March 2000 to September 2012 based on Mann–Kendall test but not over the whole study period. Structural equation modelling results indicated that precipitation and CO2 were the dominant drivers of greening. Temperature showed negative effects on vegetation greenness, indicating warming would reduce plant growth in the study region. Spatially, 75% of the region showed statistically significant greening over March 2000 to September 2012 and 39.30% for March 2000 to December 2018. The different vegetation trend results between the entire region and the pixel scale implied that location‐specific greening could be masked by an overall trend. Our study suggested that precipitation (especially the large episodic precipitation events) and CO2 are dominant drivers of the observed greening in the Namib. Our findings fill an important knowledge gap of vegetation dynamics in regions without direct human activities.
Outcomes in heart failure patients discharged to skilled nursing facilities with delirium
Authors: Lafo Jacob , Singh Mriganka , Jiang Lan , Correia Stephen , Madrigal Caroline , Clements Rachel , Wu Wen‐Chih , Erqou Sebhat , Rudolph James L. 
Published: March 2022

AbstractAimHeart failure (HF) outcomes are disproportionately worse in patients discharged to skilled nursing facilities (SNF) as opposed to home. We hypothesized that dementia and delirium were key factors influencing these differences. Our aim was to explore the associations of dementia and delirium with risk of hospital readmission and mortality in HF patients discharged to SNF.Methods and resultsThe study population included Veterans hospitalized for a primary diagnosis of HF and discharged to SNFs between 2010 and 2015. Pre‐existing dementia was identified based on International Classification of Diseases‐9 codes. Delirium was determined using the Minimum Data Set 3.0 Confusion Assessment Method algorithm. Proportional hazard regression analyses were used to model outcomes and were adjusted for covariates of interest. Patients (n = 21 655) were older (77.0 ± 10.5 years) and predominantly male (96.9%). Four groups were created according to presence (+) or absence (−) of dementia and delirium. Relative to the dementia−/delirium− group, the dementia−/delirium+ group was associated with increased 30 day mortality [adjusted hazard ratio (HR) = 2.2, 95% confidence interval (CI) = 1.7, 3.0] and 365 day mortality (adjusted HR = 1.5, 95% CI = 1.3, 1.7). Readmission was highest in the dementia−/delirium+ group after 30 days (HR = 1.2, 95% CI = 1.0, 1.5). In the group with dementia (delirium−/dementia+), 30 day mortality (12.8%; HR = 0.7, 95% CI = 0.7, 0.8) and readmissions (5.3%; HR = 1.0, 95% CI = 0.8, 1.1) were not different relative to the reference group.ConclusionsDelirium, independent of pre‐existing dementia, confers increased risk of hospital readmission and mortality in HF patients discharged to SNFs. Managing HF after hospitalization is a complex cognitive task and an increased focus on mental status in the acute care setting prior to discharge is needed to improve HF management and transitional care, mitigate adverse outcomes, and reduce healthcare costs.
Dronedarone for the treatment of atrial fibrillation with concomitant heart failure with preserved and mildly reduced ejection fraction: apost‐hocanalysis of theATHENAtrial
Authors: Vaduganathan Muthiah , Piccini Jonathan P. , Camm A. John , Crijns Harry J.G.M. , Anker Stefan D. , Butler Javed , Stewart John , Braceras Rogelio , Albuquerque Alessandro P.A. , Wieloch Mattias , Hohnloser Stefan H. 
Published: March 2022

AimsLimited therapeutic options are available for the management of atrial fibrillation/flutter (AF/AFL) with concomitant heart failure (HF) with preserved (HFpEF) and mildly reduced ejection fraction (HFmrEF). Dronedarone reduces the risk of cardiovascular events in patients with AF, but sparse data are available examining its role in patients with AF complicated by HFpEF and HFmrEF.Methods and resultsATHENA was an international, multicentre trial that randomized 4628 patients with paroxysmal or persistent AF/AFL and cardiovascular risk factors to dronedarone 400 mg twice daily versus placebo. We evaluated patients with (i) symptomatic HFpEF and HFmrEF (defined as left ventricular ejection fraction [LVEF] >40%, evidence of structural heart disease, and New York Heart Association class II/III or diuretic use), (ii) HF with reduced ejection fraction (HFrEF) or left ventricular dysfunction (LVEF ≤40%), and (iii) those without HF. We assessed effects of dronedarone versus placebo on death or cardiovascular hospitalization (primary endpoint), other key efficacy endpoints, and safety. Overall, 534 (12%) had HFpEF or HFmrEF, 422 (9%) had HFrEF or left ventricular dysfunction, and 3672 (79%) did not have HF. Patients with HFpEF and HFmrEF had a mean age of 73 ± 9 years, 37% were women, and had a mean LVEF of 57 ± 9%. Over a mean follow‐up of 21 ± 5 months, dronedarone consistently reduced risk of death or cardiovascular hospitalization (hazard ratio 0.76; 95% confidence interval 0.69–0.84) without heterogeneity based on HF status (pinteraction >0.10). This risk reduction in the primary endpoint was consistent across the range of LVEF (as a continuous function) in HF without heterogeneity (pinteraction = 0.71). Rates of death, cardiovascular hospitalization, and HF hospitalization each directionally favoured dronedarone versus placebo in HFpEF and HFmrEF, but these treatment effects were not statistically significant in this subgroup.ConclusionsDronedarone is associated with reduced cardiovascular events in patients with paroxysmal or persistent AF/AFL and HF across the spectrum of LVEF, including among those with HFpEF and HFmrEF. These data support a rationale for a future dedicated and powered clinical trial to affirm the net clinical benefit of dronedarone in this population.
Suitability of Carbazolyl Hauser and Turbo‐Hauser Bases as Magnesium‐Based Electrolytes
Authors: Schüler Philipp , Sengupta Simon , Zaubitzer Steve , Fiesinger Florian , Dongmo Saustin , Görls Helmar , Wohlfahrt‐Mehrens Margret , van den Borg Matthias , Gaissmaier Daniel , Krieck Sven , Marinaro Mario , Jacob Timo , Westerhausen Matthias 
Published: March 2022

AbstractLithium‐ion batteries pose certain drawbacks and alternatives are highly demanded. Requirements such as low corrosiveness, electrochemical stability and suitable electrolytes can be met by magnesium‐ion batteries. Metalation of carbazole with Mg in THF in the presence of ethyl bromide yields the sparingly soluble Hauser base [(thf)3Mg(Carb)Br] (1) which shows a Schlenk‐type equilibrium with formation of [(thf)3Mg(Carb)2] and [(thf)4MgBr2]. A THF solution of 1 shows a low over‐potential and a good cyclability of electrodeposition/‐stripping of Mg on a Cu current collector. An improved performance is achieved with the turbo‐Hauser bases [(thf)(Carb)Mg(μ‐Br/X)2Li(thf)2] (X=Br (2) and Cl (3)) which show a significantly higher solubility in ethereal solvents. The THF solvation energies increase from (thf)xMgBr2 over (thf)xMg(Carb)Br to (thf)xMg(Carb)2 for an equal number x of ligated THF molecules.
Formation, Chemical and Optical Properties of 1,2,5‐Triphenylpentadienyl Cation Fixed in a Rigid Dibenzobarrelene Skeleton
Authors: Ishii Akihiko , Ebina Ryota , Nakata Norio 
Published: March 2022

Abstract1,2,5‐Triphenylpentadienyl cation fused with a dibenzobarrelene skeleton was synthesized. The pentadienyl cation was persistent in the solution and characterized by 1H and 13C NMR spectroscopies. The cation abstracts a hydride from Et2O at the 5‐position to give the 5‐H derivative together with acetaldehyde and ethene. The reaction with H2O provided the 5‐OH derivative and not the 1‐OH precursor. The hydride reduction of the pentadienyl cation with silanes or NaBH4 occurred at the 3‐ and 5‐positions, and the ratio was dependent on the bulkiness of reducing reagents. The cation in dichloromethane exhibited long‐wavelength absorptions at 678, 523, and 443 nm and an emission maximum at 729 nm with the emission quantum yield of 0.175, which are longer and larger than those of the referenced 1,5‐diphenylpentadienyl cation. TD‐DFT calculations show that the absorptions are due to the π‐π* excitations on 1,2,5‐triphenylpentadienyl and dibenzobarrelene benzene rings.
Comparing Halogen Atom Abstraction Kinetics for Mn(I), Fe(I), Co(I), and Ni(I) Complexes by Combining Electroanalytical and Statistical Modeling
Authors: Tang Tianhua , Friede Nathan C. , Minteer Shelley D. , Sigman Matthew S. 
Published: March 2022

AbstractFirst‐row transition metal complexes have garnered attention due to their ability to activate aliphatic halides for catalytic cross‐coupling reactions. However, mechanistic investigation of these systems is challenging as a consequence of difficulties associated with preparing the relevant metal complexes and the resultant poor stability of such intermediates for subsequent analytical interrogation. In this context, we have developed a platform to rapidly measure kinetic data using electroanalytical methods, which facilitates a wide range of physical organic studies. As a result, we have investigated and compared the reaction of benzyllic halides with electrogenerated MnI(PyBox)Cl, FeI(Pyrox)OTf, CoI(Pyrox)Br, CoI(PyBox)Br, NiI(Phox)Br complexes. The experimental results support a unified inner‐sphere halogen atom abstraction mechanism for these different complexes while also providing the ability to directly compare through multivariate linear regression analyses the subtle differences imparted by metal/ligand combinations. The information gleaned by this study has implications why certain metal complexes are matched to oxidative addition processes relevant in catalytic processes.
Oxidative Cyclization of 4‐(2‐Mercaptophenyl)‐Substituted 4H‐1,2,4‐Triazolium Species to Tricyclic Benzothiazolium Salts
Authors: Ardón‐Muñoz Luis G. , Bolliger Jeanne L. 
Published: March 2022

AbstractHerein we report a generally applicable method for the preparation of N‐substituted benzo[4,5]thiazolo[2,3‐c][1,2,4]triazol‐1‐ium salts from air stable precursors. This transformation features selective deprotection of a para‐methoxybenzyl protected thiol followed by C−H functionalization of the linked 1,2,4‐triazolium salts under oxidative conditions. Using this procedure, we synthesized a variety of tricyclic thiazolium salts which contain both electron‐withdrawing and electron‐donating aromatic substituents as well as aliphatic substituents. Our approach also tolerates many functional groups including alkynes, alcohols, diols, amides, and polyethers.
Sensitive Electrochemical Determination of Baicalein Based on D‐Ti3C2Tx MXene/Fullerene Composite Modified Glassy Carbon Electrode
Authors: Kong Bo , Yang Xiang , Dai Huiqian , Wu Yu , Lu Hong‐Bing , Liu Wei , Liu Xiaoying 
Published: March 2022

AbstractIn this work, an electrochemical sensor was developed based on the delaminated titanium carbide nanosheet (d‐Ti3C2Tx) and fullerene (C60) composite modified glassy carbon electrode (GCE). The composite materials d‐Ti3C2Tx/C60 were characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The prepared modified electrode (d‐Ti3C2Tx/C60/GCE) exhibited commendable electrocatalytic activity for the oxidation of baicalein. Under the optimum detection conditions, the detection of baicalin showed a wide linear range of 0.015–4.0 μM with a detection limit of 0.005 μM. In addition, the d‐Ti3C2Tx/C60/GCE showed good reproducibility, stability and anti‐interference. It was also successfully used for the determination of baicalin in the commercially available Shuanghuanglian oral liquid with satisfactory results.
On the Counter‐intuitive Heterogeneous Electron Transfer Barrier Properties of Alkanethiolate Monolayers on Gold: Smooth versus Rough Surfaces
Authors: Green John‐Bruce D. , Clarke Eamonn , Porter Marc D. , McDermott Christie A. , McDermott Mark T. , Zhong Chuan‐Jian , Bergren Adam Johan 
Published: March 2022

AbstractAlkanethiolate monolayers formed on rough gold surfaces can, somewhat surprisingly, act as stronger barriers to heterogeneous electron transfer than those on smooth gold surfaces. This paper presents a possible explanation for this observation by constructing simple geometric models of a “rough” and “smooth” gold surface to examine how microscopic roughness differences can affect the nucleation/growth of the adlayer and size/density of structural defects. Expectedly, the number of defects predicted for adlayers formed on smooth gold is lower than any of those for rough gold. The counter‐intuitive result is that the sizes of a small portion of the defects in the adlayer on the smooth surface are larger than any of those found on the rough surface. The potential implications of these results are discussed.
Electrochemical Detection of Glucose and Lactate Dehydrogenase Using a Zwitterionic Phenazine Compound as an Electron Mediator for NADH Oxidation
Authors: Lee Kyuseok , Song Gyeoungsun , Kwon Jungwook , Kim Jihyeon , Yang Haesik 
Published: March 2022

AbstractPhenazine compounds have been used as simple organic catalysts for the rapid oxidation of NADH. Although positively charged phenazine compounds are highly water‐soluble, their uncharged, reduced forms are not. We report the use of a zwitterionic phenazine compound, 3‐(1‐methoxyphenazin‐5‐ium‐5‐yl)propane‐1‐sulfonate (mPPS), as an organic catalyst and electron mediator for the electrochemical oxidation of NADH and detection of glucose and lactate dehydrogenase (LDH). mPPS is highly stable in phosphate buffered saline (pH 7.4). Furthermore, the negatively charged, reduced form of mPPS is highly water‐soluble. The detection limits of glucose and LDH in artificial serum were approximately 0.02 mM and 2 ng/mL, respectively.
Preparation and performance evaluation of hybrid polymer flocculants (PAC‐PAM), and comparison experiments with other flocculants
Authors: Yao Bin , Zhao Deyin , Guo Ji , Yan Chaozong , Zheng Cunchuan 
Published: March 2022

AbstractUsing the initiator system of potassium persulfate, a new PAC‐PAM organic–inorganic hybrid flocculant was synthesized. This flocculant is used in sewage disposal. When the dosage was 10 mg/L and initial turbidity was 160 NTU, the turbidity removal rate of the heterogeneous flocculant reached the highest point of 95.04%, the water treatment effect of the hybrid flocculant is higher than that of other flocculants. The optimal experimental conditions in this experiment were as follows: the ratio of AM monomer to PAC was 8:2, the mass fraction of the added initiator was 0.2 wt%, the reaction temperature was 50°C, the reaction time was 4 h, and the pH of the effluent was neutral or weakly basic. Under the same dosage and different initial turbidity, the turbidity removal effect of hybrid flocculant is better than compound flocculant and PAM or PAC. The results show that the hybrid flocculant is a new material, which is different from the compound flocculant. Moreover, the hybrid flocculant is almost non‐corrosive to the equipment and has the prospect of industrial application.
Pulse‐period – moment‐magnitude relations derived with wavelet analysis and their relevance to estimate structural deformations
Authors: Efthymiou Eleftheria , Makris Nicos 
Published: March 2022

AbstractMotivated from the quadratic dependence of peak structural displacements to the pulse period, , of pulse‐like ground motions, this paper revisits the pulse‐period – moment‐magnitude (–) relations of ground motions generated from recorded near‐source ground motions with epicentral distances, 20 km. A total of 1260 ground motions are interrogated with wavelet analysis to identify energetic acceleration pulses (not velocity pulses) and extract their optimal period, , amplitude, , phase, and number of half‐cycles, . The interrogation of acceleration records with wavelet analysis is capable of extracting shorter‐duration distinguishable pulses with engineering significance, which override the longer near‐source pulses and they are not necessarily of random character. Our wavelet analysis identified 109 pulse‐like records from normal faults, 188 pulse‐like records from reverse faults and 125 pulse‐like records from strike‐slip faults, all with epicentral distances 20 km. Regression analysis on the extracted data concluded that the same – relation can be used for pulse‐like ground motions generated either from strike‐slip faults or from dip‐slip normal faults; whereas, a different – relation is proposed for dip‐slip reverse faults. The study concludes that for the same moment magnitude, , the pulse periods of ground motions generated from strike‐slip faults are on average larger than these from reverse faults — a result that is in agreement with findings from past investigations. Most importantly, our wavelet analysis on acceleration records produces – relations with a slope that is lower than the slopes of the – relations presented by past investigators after merely fitting velocity pulses. As a result, our proposed – relations yield lower values for larger‐magnitude earthquakes (say 6), allowing for the estimation of dependable peak structural displacements that scale invariably with .
Zum Erdruhedruckbeiwert nach Jáky
Authors: Hettler Achim , Vrettos Christos 
Published: March 2022

AbstractZur Berechnung des Erdruhedruckbeiwerts hat sich für horizontales Gelände unter Bodeneigengewicht und ohne Vorbelastung die empirische Näherungsformel nach Jáky durchgesetzt. In einer neueren Arbeit stellt Goldscheider auf Grundlage von theoretischen Untersuchungen und hochgenauen Quaderverformungsversuchen an Sand mit proportionalen Spannungs‐ und Verformungspfaden fest, dass der Vorschlag von Jáky durchgängig zu kleine Werte liefert. Es stellt sich die Frage nach den Auswirkungen auf die Nachweise der Standsicherheit und der Gebrauchstauglichkeit. Im Beitrag wird über die Ergebnisse der Diskussionen im Arbeitskreis „Baugruben“ sowie in dem für die DIN 4085 zuständigen Ausschuss berichtet und ein eigener Ansatz vorgestellt, der die Ergebnisse von Goldscheider genauer wiedergibt als der Ansatz nach Jáky.
Generation of Cyclopentadiene for Diels–Alder Reactions by Visible‐Light Irradiation of Iron Sandwich Complexes
Authors: Sokolov Alexey S. , Polezhaev Alexander V. , Nelyubina Yulia V. , Perekalin Dmitry S. 
Published: March 2022

AbstractCyclopentadienes readily undergo fast and selective Diels–Alder reactions which can be used for conjugation of biomolecules and polymers. Herein we present a new method for the photochemical generation of cyclopentadienes by the visible light irradiation of the iron complexes [(C5H4R)Fe(arene)]+. This reaction proceeds at room temperature, in water, and in the presence of potentially interfering amino acids. Free cyclopentadiene is trapped by dienophiles to give the corresponding Diels–Alder adducts in 72–95 % yield.
iNAP: An integrated network analysis pipeline for microbiome studies
Authors: Feng Kai , Peng Xi , Zhang Zheng , Gu Songsong , He Qing , Shen Wenli , Wang Zhujun , Wang Danrui , Hu Qiulong , Li Yan , Wang Shang , Deng Ye 
Published: March 2022

AbstractIntegrated network analysis pipeline (iNAP) is an online analysis pipeline for generating and analyzing comprehensive ecological networks in microbiome studies. It is implemented in two sections, that is, network construction and network analysis, and integrates many open‐access tools. Network construction contains multiple feasible alternatives, including correlation‐based approaches (Pearson's correlation and Spearman's rank correlation along with random matrix theory, and sparse correlations for compositional data) and conditional dependence‐based methods (extended local similarity analysis and sparse inverse covariance estimation for ecological association inference), while network analysis provides topological structures at different levels and the potential effects of environmental factors on network structures. Considering the full workflow, from microbiome data set to network result, iNAP contains the molecular ecological network analysis pipeline and interdomain ecological network analysis pipeline (IDENAP), which correspond to the intradomain and interdomain associations of microbial species at multiple taxonomic levels. Here, we describe the detailed workflow by taking IDENAP as an example and show the comprehensive steps to assist researchers to conduct the relevant analyses using their own data sets. Afterwards, some auxiliary tools facilitating the pipeline are introduced to effectively aid in the switch from local analysis to online operations. Therefore, iNAP, as an easy‐to‐use platform that provides multiple network‐associated tools and approaches, can enable researchers to better understand the organization of microbial communities. iNAP is available at http://mem.rcees.ac.cn:8081 with free registration.
Thrombospondins in human aortic aneurysms
Authors: Plana Emma , Oto Julia , Medina Pilar , Herranz Raquel , Fernández‐Pardo Álvaro , Requejo Lucia , Miralles Manuel 
Published: March 2022

AbstractThrombospondins are a family of matricellular proteins with a multimeric structure that is known to be involved in several biological and pathological processes. Their relationship with vascular disorders has raised special interest recently. Aortic aneurysms are related to the impairment of vascular remodeling, in which extracellular matrix proteins seem to play an important role. Thus, research in thrombospondins, and their potential role in aneurysm development is progressively gaining importance. Nevertheless, studies showing thrombospondin dysregulation in human samples are still scarce. Although studies performed in vitro and in vivo models are essential to understand the molecular mechanisms and pathways underlying the disorder, descriptive studies in human samples are also necessary to ascertain their real value as biomarkers and/or novel therapeutic targets. The present article reviews the latest findings regarding the role of thrombospondins in aortic aneurysm development, paying particular attention to the studies performed in human samples.