bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paraoxonase‐1 (PON1) Status Analysis Using Non‐Organophosphate Substrates
Authors: Marsillach Judit , Richter Rebecca J. , Costa Lucio G. , Furlong Clement E. 
Published: January 2021

AbstractHuman paraoxonase‐1 (PON1) is a high‐density lipoprotein‐associated enzyme with antioxidant, anti‐inflammatory, and antiapoptotic roles. The ability of PON1 to hydrolyze specific organophosphate (OP) compounds and prevent accumulation of oxidized lipids in lipoproteins has prompted a large number of studies investigating PON1's role in modulating toxicity and disease. Most of these studies, however, have only focused on PON1 single nucleotide polymorphism analyses and have ignored PON1 activity levels, arguably the most important parameter in determining protection against exposure and disease. We developed a two‐substrate activity assay termed “PON1 status” that reveals both the functional PON1192 genotype and plasma PON1 activity levels. While our previous studies with PON1 status demonstrated that both PON1192 functional genotype and enzymatic activity levels obtained exclusively by determining PON1 status are required for a proper evaluation of PON1's role in modulating OP exposures and risk of disease, the original PON1 status assay requires the use of highly toxic OP metabolites. As many laboratories are not prepared to handle such toxic compounds and the associated waste generated, determination of PON1 status has been limited to rather few studies. Here, we describe a PON1 status protocol that uses non‐OP substrates with a resolution equivalent to that of the original PON1 status approach. We have also included useful suggestions to ensure the assays can easily be carried out in any laboratory. The protocols described here will enable a proper examination of the risk of exposure or susceptibility to disease in PON1 epidemiological studies without the need to handle highly toxic substrates. © 2021 Wiley Periodicals LLC.This article was corrected on 18 July 2022. See the end of the full text for details.Basic Protocol: Determining PON1 status using non‐organophosphate substratesSupport Protocol 1: Experimental pathlength determinationSupport Protocol 2: PON1 DNA genotyping for the Q192R (rs662) polymorphism
A 24‐hour operational single‐phase quasi‐Z‐source photovoltaic power system
Authors: Wei Xianglin , Liu Yushan , Wang Han , Zhang Wanhong , Chen Wei , Yang Weiman , Huang Surong 
Published: January 2021

SummaryBattery energy stored single‐phase quasi‐Z‐source inverter photovoltaic (BES‐qZSI‐PV) power system shows many advantages in comparison with other tri‐port inverter‐based PV power systems. However, the existing BES‐qZSI‐PV power system does not work at night or cloudy day because of its circuit limitation. This paper proposes a 24‐h operational BES‐qZS‐PV system by the following approaches: (1) the main power circuit is proposed for the day and night operation; (2) the detailed circuit models including the DC model and the second‐harmonics ripple model are built by considering scenarios of day and night operations; (3) the design method of quasi‐Z‐source network parameters is proposed to meet the requirement of day and night operations; and (4) the control strategy is proposed to achieve the high‐performance system operation all the time and seamless transition between day and night operation. After theoretical modeling and analysis, the built models are verified by comparing their calculation results with the circuit‐based simulation and experimental results. The proposed single‐phase BES‐qZSI‐PV power system is tested; experimental and simulation results are captured when the system operates in day, night, and transition to validate the proposed 24‐h operational BES‐qZSI‐PV system.
Bringing function to structure: Root–soil interactions shaping phosphatase activity throughout a soil profile in Puerto Rico
Authors: Cabugao Kristine Grace , Yaffar Daniela , Stenson Nathan , Childs Joanne , Phillips Jana , Mayes Melanie A. , Yang Xiaojuan , Weston David J. , Norby Richard J. 
Published: January 2021

Abstract

Large areas of highly productive tropical forests occur on weathered soils with low concentrations of available phosphorus (P). In such forests, root and microbial production of acid phosphatase enzymes capable of mineralizing organic phosphorus is considered vital to increasing available P for plant uptake.

We measured both root and soil phosphatase throughout depth and alongside a variety of root and soil factors to better understand the potential of roots and soil biota to increase P availability and to constrain estimates of the biochemical mineralization within ecosystem models.

We measured soil phosphatase down to 1 m, root phosphatase to 30 cm, and collected data on fine‐root mass density, specific root length, soil P, bulk density, and soil texture using soil cores in four tropical forests within the Luquillo Experimental Forest in Puerto Rico.

We found that soil phosphatase decreased with soil depth, but not root phosphatase. Furthermore, when both soil and root phosphatase were expressed per soil volume, soil phosphatase was 100‐fold higher that root phosphatase.

Both root and soil factors influenced soil and root phosphatase. Soil phosphatase increased with fine‐root mass density and organic P, which together explained over 50% of the variation in soil phosphatase. Over 80% of the variation in root phosphatase per unit root mass was attributed to specific root length (positive correlation) and available (resin) P (negative correlation).

Synthesis: Fine‐root traits and soil P data are necessary to understand and represent soil and root phosphatase activity throughout the soil column and across sites with different soil conditions and tree species. These findings can be used to parameterize or benchmark estimates of biochemical mineralization in ecosystem models that contain fine‐root biomass and soil P distributions throughout depth.
Queen execution in a monogynous ant
Authors: Giehr Julia , Heinze Jürgen 
Published: January 2021

AbstractWorkers in many species of social insects are capable of laying unfertilized eggs, which can develop into haploid males. This causes a conflict about male parentage between queens and workers. In a few species, this may result in matricide, that is, workers kill the colony's queen. Queen killing has so far been observed mainly in multi‐queen colonies or in annual species, when the queen's fecundity declines at the end of the reproductive period. Here, we report queen expulsion and matricide in a monogynous, monandrous ant with perennial societies. Workers were seen to aggressively expel both related and unrelated queens from their nest shortly after the end of hibernation. Queen expulsion and matricide led to a significant decrease in the number of workers and brood, but eventually increased the direct fitness of workers through significant male production. Long‐term observations revealed a short lifespan of queens, while workers in orphaned colonies survived and produced male offspring over several years.
Age‐ and sex‐related dietary specialization facilitate seasonal resource partitioning in a migratory shorebird
Authors: Hall Laurie A. , De La Cruz Susan E. W. , Woo Isa , Kuwae Tomohiro , Takekawa John Y. 
Published: January 2021

AbstractDietary specialization is common in animals and has important implications for individual fitness, inter‐ and intraspecific competition, and the adaptive potential of a species. Diet composition can be influenced by age‐ and sex‐related factors including an individual's morphology, social status, and acquired skills; however, specialization may only be necessary when competition is intensified by high population densities or increased energetic demands.To better understand the role of age‐ and sex‐related dietary specialization in facilitating seasonal resource partitioning, we inferred the contribution of biofilm, microphytobenthos, and benthic invertebrates to the diets of western sandpipers (Calidris mauri) from different demographic groups during mid‐winter (January/February) and at the onset of the breeding migration (April) using stable isotope mixing models. Western sandpipers are sexually dimorphic with females having significantly greater body mass and bill length than males.Diet composition differed between seasons and among demographic groups. In winter, prey consumption was similar among demographic groups, but, in spring, diet composition differed with bill length and body mass explaining 31% of the total variation in diet composition. Epifaunal invertebrates made up a greater proportion of the diet in males which had lesser mass and shorter bills than females. Consumption of Polychaeta increased with increasing bill length and was greatest in adult females. In contrast, consumption of microphytobenthos, thought to be an important food source for migrating sandpipers, increased with decreasing bill length and was greatest in juvenile males.Our results provide the first evidence that age‐ and sex‐related dietary specialization in western sandpipers facilitate seasonal resource partitioning that could reduce competition during spring at the onset of the breeding migration.Our study underscores the importance of examining resource partitioning throughout the annual cycle to inform fitness and demographic models and facilitate conservation efforts.
Temporal resource partitioning of wildebeest carcasses by scavengers after riverine mass mortality events
Authors: Handler Katherine S. , Subalusky Amanda L. , Kendall Corinne J. , Dutton Christopher L. , Rosi Emma J. , Post David M. 
Published: January 2021

AbstractScavengers play an important role in nutrient recycling and disease control, and this role may be particularly critical after mass mortality events, such as those caused by epidemics, culling, or natural disasters. Current work on scavenger ecology has focused on use of single carcasses, but behaviors are likely to be different at mass mortality events, in which high resource abundance can prolong the spatial and temporal availability of carcasses. Little is currently known about how scavengers respond to large die‐offs and understanding scavenger use and succession patterns at mass mortality events has important implications for disease ecology. We used photographic time series and river‐side surveys of scavengers using carcasses to investigate scavenger use and succession on wildebeest carcasses that resulted from annual mass drownings in the Mara River, Kenya. In addition, we used telemetry data for tagged avian scavengers to assess individual use of mass drownings. Density of avian scavengers per carcass was almost two orders of magnitude lower at mass drownings than has been documented previously for single carcasses on land. Scavengers demonstrated patterns of temporal resource partitioning, with large‐bodied avian scavengers more common initially, followed by small‐bodied avian scavengers, and then by insectivorous birds and non‐avian scavengers. Avian scavengers also differed in daily activity patterns, with marabou storks more common in the morning and late afternoon and white‐backed and Rüppell’s vultures more common mid‐day. Telemetry data indicated that approximately half of tagged vultures used mass drowning events but only spent a small proportion of their time there, suggesting that competition still plays an important role in scavenger dynamics at mass mortality events and that the rewards of such abundant resources may be offset by the risk of foraging in the river. Further research on scavenger behavior during mass mortality events is needed to better understand the role of scavengers in decomposition of carcasses and disease control during these events.
Demographic performance of a large herbivore: effects of winter nutrition and weather
Authors: Jackson Nathan J. , Stewart Kelley M. , Wisdom Michael J. , Clark Darren A. , Rowland Mary M. 
Published: January 2021

AbstractVariation among demographic rates for a population reflects the allocation of available energy by individuals to competing life‐history strategies. Species exhibiting slow‐paced life histories often prioritize energy allocation to adult survival over any single reproductive event, therefore maximizing future reproductive potential. Survival of adult female ungulates is generally high with little variability, whereas survival of young is lower and often highly variable. When adult survival is high with low variability, juvenile survival may have a proportionally greater effect on population growth or decline. Weather also may affect population dynamics directly by influencing survival of young or adults, or indirectly through changes in nutritional condition of adult females that influence population growth rates. We experimentally manipulated forage availability during winter, by supplementing native forage with high‐energy pelleted feed ad libitum, to a subset of a population of mule deer (Odocoileus hemionus) to understand the effects of winter nutrition on survival of adult females and their young born the subsequent summer. We evaluated the effects of winter nutrition, individual‐based parameters, and environmental covariates on survival of adult female mule deer from 2013 to 2018, and neonatal mule deer from 2014 to 2016. We documented a 26% decrease in annual survival of adult female mule deer in 2017 in response to increased snowpack during the preceding winter. Neonates born to females that receive enhanced nutrition during winter preceding parturition had higher survival to weaning (0.49, SE = 0.12), compared to neonates born to females that did not receive enhanced nutrition (0.29, SE = 0.07). We observed no effect of enhanced winter nutrition on survival of adult females. Our results suggested winter nutrition of maternal females may influence juvenile survival and demonstrates the importance of forage quality available to adult females during mid‐pregnancy. Although we were unable to detect an effect of winter forage on survival of adults, direct effects of deep winter snow resulted in lower survival of adult females. Low survival of adult females in our study population is indicative of a declining population.
A clinical score for predicting left ventricular reverse remodelling in patients with dilated cardiomyopathy
Authors: Kimura Yuki , Okumura Takahiro , Morimoto Ryota , Kazama Shingo , Shibata Naoki , Oishi Hideo , Araki Takashi , Mizutani Takashi , Kuwayama Tasuku , Hiraiwa Hiroaki , Kondo Toru , Murohara Toyoaki 
Published: January 2021

AbstractAimsLeft ventricular reverse remodelling (LVRR) is a well‐established predictor of a good prognosis in patients with dilated cardiomyopathy (DCM). The prediction of LVRR is important when developing a long‐term treatment strategy. This study aimed to assess the clinical predictors of LVRR and establish a scoring system for predicting LVRR in patients with DCM that can be used at any institution.Methods and resultsWe consecutively enrolled 131 patients with DCM and assessed the clinical predictors of LVRR. LVRR was defined as an absolute increase in left ventricular ejection fraction (LVEF) from ≥10% to a final value of >35%, accompanied by a decrease in left ventricular end‐diastolic dimension (LVEDD) ≥ 10% on echocardiography at 1 ± 0.5 years after a diagnosis of DCM. The mean patient age was 50.1 ± 11.9 years. The mean LVEF was 32.2 ± 9.5%, and the mean LVEDD was 64.1 ± 12.5 mm at diagnosis. LVRR was observed in 45 patients (34%) at 1 ± 0.5 years. In a multivariate analysis, hypertension [odds ratio (OR): 6.86; P = 0.002], no family history of DCM (OR: 10.45; P = 0.037), symptom duration <90 days (OR: 6.72; P < 0.001), LVEF <35% (OR: 13.66; P < 0.0001), and QRS duration <116 ms (OR: 5.94; P = 0.005) were found to be independent predictors of LVRR. We scored the five independent predictors according to the ORs (1 point, 2 points, 1 point, 2 points, and 1 point, respectively), and the total LVRR predicting score was calculated by adding these scores. The LVRR rate was stratified by the LVRR predicting score (0–2 points: 0%; 3 points: 6.7%; 4 points: 17.4%; 5 points: 48.2%; 6 points: 79.2%; and 7 points: 100%). The cut‐off value of the LVRR predicting score was >5 in receiver‐operating characteristic curve analysis (area under the curve: 0.89; P < 0.0001; sensitivity: 87%; specificity: 78%). An LVRR predicting score of >5 was an independent predictor compared with the presence of late gadolinium enhancement on cardiovascular magnetic resonance or the severity of fibrosis on endomyocardial biopsy (OR: 11.79; 95% confidence interval: 2.40–58.00; P = 0.002).ConclusionsThe LVRR predicting score using five predictors including hypertension, no family history of DCM, symptom duration <90 days, LVEF <35%, and QRS duration <116 ms can stratify the LVRR rate in patients with DCM. The LVRR predicting score may be a useful clinical tool that can be used easily at any institution.
Tunable Potassium Ion Conductivity and Magnetism in Substituted Layered Ferrates
Authors: Albrecht Ralf , Hunger Jens , Hoelzel Markus , Suard Emmanuelle , Schnelle Walter , Doert Thomas , Ruck Michael 
Published: January 2021

AbstractFive substituted oxohydroxoferrates K2–x(Fe,M)4O7–y(OH)y (M=Si, Ge, Ti, Mn, Ir) were synthesized in a potassium hydroxide hydroflux with a molar base‐water ratio q(K) of about 0.9. While the hexagonal prisms of K2–x(Fe,Ti)4O7–y(OH)y crystallize in P63/mcm, all other compounds form hexagonal plates with the trigonal space group P
1 m. The crystal structure of the oxohydroxoferrates resembles ß‐alumina. It consists of honeycomb layers
Fe2O6] of edge‐sharing [FeO6] octahedra, where the hexagonal voids are capped by vertex‐sharing [FeO4] tetrahedra pairs. The cavities between the oxoferrate layers host the potassium ions. Depending on M, the substitution affects different iron positions and varies between 5 and 20 %. The magnetic structures of the antiferromagnetic compounds were determined by neutron powder diffraction. The potassium ion conductivity was characterized by electrochemical impedance spectroscopy at room temperature. By storing the oxohydroxoferrates in air or annealing them at 700 °C the ion conductivity was significantly increased, e. g. to 5.0 ⋅ 10−3 S cm−1 for a pressed pellet of the iridium substituted compound.
Iron‐Iron Bond Lengths and Bond Orders in Diiron Lantern‐Type Complexes with High Spin Ground States
Authors: Hujon Fitzerald , Lyngdoh Richard H. Duncan , King R. Bruce 
Published: January 2021

AbstractDiiron paddlewheel‐ or lantern‐type complexes comprise an interesting subclass of binuclear iron complexes, existing with digonal, trigonal, and tetragonal ligand arrays. Experimentally known members show Fe−Fe bonds of lengths ranging from 2.13 to 2.73 Å, with Fe−Fe bond orders ranging from 0.5 to 2. Truncated models for 30 experimentally characterized diiron paddlewheel‐type complexes have been studied by DFT using the M06‐L functional, reproducing the Fe−Fe bond lengths quite well. In addition, we use DFT to treat three series of model diiron complexes Fe2Lx (x=2, 3, 4) in various low‐lying spin states, L being the unsubstituted formamidinate, guanidinate, and formate ligands (along with a series of axially ligated formate complexes) in order to predict ground state spin multiplicities, Fe−Fe bond lengths, and features of the ligand arrays. The ground states all have high spin multiplicities (septets, octets, and nonets). Formal bond order (fBO) values are suggested for the Fe−Fe bonds in these 61 complexes using an electron bookkeeping procedure, in addition to the Fe−Fe bond orders obtained by metal‐metal MO analysis for ground state species. Fe−Fe bond orders up to 3 are noted in some excited states. Deviations from D3h and D4h symmetry are noted for many trigonal and tetragonal complexes, being attributed to inherent Jahn‐Teller distortions. The formamidinate and guanidinate series show many similarities, while the formate series differs from these two in several aspects. From these results, ranges are derived for Fe−Fe bond lengths of orders 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0. The Fe−Fe bond length ranges for these non‐carbonyl lantern complexes are found to be appreciably lower than the corresponding ranges for diiron complexes with carbonyl ligands as compiled earlier from computational and experimental results.
Ferrocene‐Fused Acenequinones: Synthesis, Structure and Reaction Chemistry
Authors: Mahrholdt Julia , Kovalski Eduard , Korb Marcus , Hildebrandt Alexander , Vrček Valerije , Lang Heinrich 
Published: January 2021

AbstractThe synthesis of anti‐[1.1](2,17)(6,13)ferrocenophane‐1,12‐dione (2) is discussed. By addition of LiAlH4, NaBH4 or Wittig's reagent only one keto group reacted to give HO‐ or cC3H4‐functionalized [1.1](2,17)(6,13)ferrocenophan‐12‐hydroxy‐1‐one (3) and [1.1](2,17)(6,13)ferrocenophan‐12‐cyclopropane‐1‐one (4). Exchange of CO by CS groups is possible upon addition of Lawesson's reagent to 2 forming [1.1](2,17)(6,13)ferrocenophan‐1,12‐dithioketone (5). Theoretical studies confirm the different reactivities of the CO groups. Electrochemical studies on 2–5 showed separated reversible one‐electron events for 2–4 (125–925 mV) and an irreversible one for 5. The ferrocenyls in 4 are easier to oxidize, due to their higher electron‐richness. In 2 a larger redox separation comes about suggesting a stronger intermetallic interaction between FeII/FeIII in the mixed‐valent species. In situ UV‐vis/NIR studies confirm that 2 is a weak coupled class II system according to the classification of Robin and Day. Compounds 3 and 4 display electrostatic interactions among the ferrocenyls as oxidation progresses.
Green‐Blue Phosphorescent Iridium(III) Complexes with Near Unitary Quantum Yield
Authors: Soellner Johannes , Strassner Thomas 
Published: January 2021

AbstractIridium(III) complexes with cyclometalating ligands can achieve excellent properties for use as phosphorescent emitters in organic light emitting diodes. A series of complexes with 2‐phenyl‐pyridine and bis(pyrazolyl)borate ligands was investigated with regard to this application. The sky‐blue to green emitters showed nearly unitary quantum yields and short excited state lifetimes.
Development of Pd Supported Catalysts Using Thiol‐Functionalized Mesoporous Silica Frameworks: Application to the Chemo‐ and Regioselective C‐3 Arylation of Free‐Indole
Authors: Renom Carrasco Marc , Khodja Walid , Demarcy Clément , Veyre Laurent , Camp Clément , Thieuleux Chloé 
Published: January 2021

AbstractWe report here the development of Pd‐supported catalysts for the selective C‐3 arylation of free‐indole using thiol‐functionalized silica supports to anchor the palladium centers. The palladium (II) complex, Pd(OAc)2, was efficiently loaded into various thiol‐functionalized mesostructured silicas at room temperature. These materials exhibit different contents of surface SH groups (0.3 to 1.8 SH/nm2) and various SH/Pd molar ratios from 6 to 65. It was found that the catalysts containing the most isolated surface SH groups (0.3 SH/nm2) and the highest loading of Pd were the most active, reaching 70 % of conversion, 1400 as turnover numbers and 100 % selectivity in the C‐3 arylated product using only 0.05 mol % of Pd. However, a leaching of active Pd species (1.7 ppm) was detected. The best compromise was found for a specific solid containing isolated surface thiol groups (0.3 SH/nm2) and a very low loading of Pd (SH/Pd=65). It exhibited a high TON (608) with a very low Pd leaching of 0.5 ppm in the course of the catalytic reaction. These results thus illustrate that both surface SH sites isolation and concentration, as well as the SH/Pd molar ratio are key parameters to access high catalytic performances and very low leaching of metal during catalysis.