bluuebunny/crossref_metadata_2025_split huggingface dataset:
Construction of C‐N Atropisomers by Aminocatalytic Enantioselective Addition of Indole‐2‐carboxaldehydes too‐Quinone Derivatives
Authors: Corti Vasco , Thøgersen Mathias Kirk , Enemærke Valdemar Juel , Rezayee Nomaan M. , Barløse Casper L. , Anker Jørgensen Karl 
Published: August 2022

AbstractThe first atroposelective aminocatalytic methodology for the construction of C−N atropisomers is presented. The synthesis of this class of axially chiral molecules typically encompasses substrates in which the C−N bond is pre‐formed. In contrast, this work presents the direct coupling of indole‐2‐carboxaldehydes toortho‐quinones, to form the stereogenic C−N axis in an atroposelective way. Application of typical secondary amine catalysts furnished the desired product, however, in low yields and as a complex mixture arising from poor regiocontrol among the C3‐ and N1‐sites of the indole core. A new aminocatalyst was designed and synthesized with increased outer‐sphere steric bulk to address these challenges thereby providing good levels of regio‐ and enantioselectivity. A novel library of functionalized and enantioenriched C−N atropisomers was obtained and their synthetic utility was demonstrated by various transformations.
Boron‐, Sulfur‐ andNitrogen‐DopedTridecacyclic Aromatic Emitters with Multiple Resonance Effect for Narrowband Red Emission†
Authors: Wang Yinuo , Zhang Kaiyuan , Chen Fan , Wang Xingdong , Yang Qingqing , Wang Shumeng , Shao Shiyang , Wang Lixiang 
Published: August 2022

Comprehensive SummaryTwo novel boron (B), sulfur (S), nitrogen (N)‐doped polycyclic aromatic hydrocarbon multiple resonance emitters (DBNS and DBNS‐tBu) are designed and synthesized for narrowband red emission by embedding two pairs of S and N atoms and two B atoms inpara‐positions of central benzene rings within a tridecacyclic aromatic skeleton to form donor‐π‐donor (D‐π‐D) and acceptor‐π‐acceptor (A‐π‐A) structures, which not only exhibit emission maximum at 641 nm with small full width at half maximum of 39 nm, but also combine high photoluminescent quantum efficiency (85%) and rapid reverse intersystem crossing (kRISC = 2.2 × 105s−1), giving rise to red electroluminescence with color coordinates of (0.65, 0.34) and maximum external quantum efficiency of 7.8% via solution process.
Clinically unrecognized plasma volume expansion predicts long‐term all‐cause‐mortality in chronic heart failure
Authors: Ahlgrim Christoph , Seiler Florian , Birkner Philipp , Schoechlin Simon , Grundmann Sebastian , Bode Christoph , Pottgiesser Torben 
Published: August 2022

AbstractIntroductionChronic heart failure (CHF) is associated with elevated total blood volume (BV) and distinct phenotypes of total red cell volume (RCV) and plasma volume (PV) elevations. Especially PV expansion during clinical decompensation is linked with adverse clinical outcomes. The role of PV expansion in compensated CHF patients is less clear. Aim of the present study is to investigate the impact of BV parameters on long‐term mortality in CHF patients investigated at a compensated state.Methods and ResultsBV, PV and RCV were determined in 44 (9 female) compensated CHF patients using an abbreviated carbon monoxide method, who were followed up for 6.0 years, (range: 3.7–6.5 years) for all‐cause mortality. In univariate analysis PV expansion but not BV and RCV predicted all‐cause mortality (p = .021). A cutoff of 1800 ml PV/m² body‐surface area allows stratification for all‐cause mortality (p = .044). PV expansion but not RCV reduction explains the significantly lower hematocrit values of nonsurvivors.DiscussionIn this pilot study, PV expansion, which was unnoticed from a clinician's perspective, but is indicated by significantly lower hematocrit, appears to be a relevant predictor of long‐term all‐cause mortality. Whether PV expansion constitutes an adverse CHF phenotype and can be targeted by diuretic therapy is currently unclear.
Toward modeling thrombosis and thromboembolism in laminar and turbulent flow regimes
Authors: Tobin Nicolas , Manning Keefe B. 
Published: August 2022

AbstractThrombosis and thromboembolism are deadly risk factors in blood‐contacting biomedical devices, and in‐silico models of thrombosis are attractive tools to understand the mechanics of these processes, though the simulation of thromboembolism remains underdeveloped. The purpose of this study is to modify an existing computational thrombosis model to allow for thromboembolism and to investigate the behavior of the modified model at a range of flow rates. The new and existing models are observed to lead to similar predictions of thrombosis in a canonical backward‐facing step geometry across flow rates, and neither model predicts thrombosis in a turbulent flow. Simulations are performed by increasing flow rates in the case of a clot formed at lower flow to induce embolization. While embolization is observed, most of the clot breakdown is by shear rather than by breakup and subsequent transport of clotted material, and further work is required in the formulation and validation of embolization. This model provides a framework to further investigate thromboembolization.
The Effect of pH on the Structure and Lateral Organization of Cardiolipin in Langmuir Monolayers
Authors: Sturm Marina , Gutowski Olof , Brezesinski Gerald 
Published: August 2022

AbstractCardiolipin (CL) is a unique phospholipid featuring a dimeric structure. With its four alkyl chains, it has a large hydrophobic region and the charged hydrophilic head group is relatively small. Biological membranes exhibit CL exclusively in the inner bacterial and mitochondrial membranes. Alteration of CL packing can lead to structural changes and membrane instabilities. One environmental influence is the change in pH. Since the acidic properties of the phosphate head groups remain still controversial in literature, this work focusses on the influence of pH on the ionization degree of CL. For the analyses, surface pressure (π) – molecular area (A) isotherm experiments were combined with total reflection X‐ray fluorescence (TRXF) and grazing incidence X‐ray diffraction (GIXD). Continuous ionization with a high CL packing density was observed in the monolayer over a wide pH range. No individual pKa values can be assigned to the two phosphate groups, but mutual influence is observed.
Nematic‐type Structure of the SnO2(110) Surface at Room Temperature
Authors: Liu Shengsheng , Cheng Zhiying , Yu Rong 
Published: August 2022

AbstractThe most exposed (110) surface of SnO2 plays an important role in practical applications like gas sensors and catalysts. It has previously been considered to be amorphous at room temperature. In this study, the structure of the (110) surface stabilized at room temperature is determined using aberration‐corrected transmission electron microscopy and first‐principles calculations. The (110) surface has local order and is made of Sn2O2 strands that partially cover underlying unsaturated Sn rows. The results indicate that the Sn2O2 strands assemble as building blocks on the surface to form a partially ordered structure, quite like the nematic liquid crystal. Partial occupation of the Sn2O2 strands along the [
0] direction avoids the interaction between neighboring Sn2O2 strands and therefore makes the surface more stable. The novel phenomenon of the surface provides insight for understanding and developing catalysts and gas sensors based on SnO2.
Center Atom Model for Strain Mapping of Void and Crack of Atomic Lattice Image
Authors: Li Yi‐xuan , Gao Ying‐jun , Liao Kun , Deng Qian‐qian , Huang Zong‐ji , Yi Xiao‐Ai , Luo Zhi‐rong 
Published: August 2022

AbstractAiming at the strain distribution around the atomic lattice defect with void and crack in crystal materials, a new elastic strain calculation method named as center atom model (CAM) is proposed in this work, and is applied for mapping the strain field of the defect with void in an atomic image lattice in real space under external forcing. As an example, the strain mapping of voids and cracks of an atomic lattice image from phase field crystal (PFC) model is quantitatively characterized by CAM. The results show that CAM can well be used to extract the strain information from various types of the defect surface of atomic lattice images. Wherever the strain distribution around the dislocation of the grain boundary or the strain around the void and crack is, CAM can accurately extract the strain distribution of the distortion area of the atomic lattice. CAM can also be easily extended and applied to the strain mapping of the defects in the heterogeneous interface.
Growth of ZnTe Semiconductor Crystal Via a Te Flux Zone Melting Method and Characterization of Its Properties
Authors: Jin Min , He Feng , Zheng Shuying , Xu Yadong , Peng Yan , Chen Xiufei , Xu Xiangang 
Published: August 2022

AbstractIn this work, a kind of II;‐VI group ZnTe semiconductor crystal is successfully grown using a Te flux zone melting method from Zn: Te = 3: 7 mole ratio solution. The crystal has standard F43m cubic space group and the a/b/c lattice constants are all calculated to be 6.105 Å. Energy dispersive spectroscopy analysis confirms it has quasistoichiometric ratio and the Zn/Te elements are distributed in the material homogeneously. The polished 1.0 mm thickness (110) wafer exhibits a highest ≈64.5% transmittance near 2400 nm wavelength and the bandgap Eg is deduced as 2.223 eV. ZnTe crystal shows a heavy volatilization start from 910 °C and the weight losing speed is about ≈1.45% min−1. The thermal conductivity k displays good repeatability in the cooling and heating stages, the k value is about 15.8 Wm−1 K−1 at room temperature and is deceased to 3.53 Wm−1 K−1 under 500 °C. These results would be of great reference when ZnTe crystal is used for device design and application in the future.
Detection of AP‐237 and synthetic cannabinoids on an infused letter sent to a German prisoner
Authors: Giorgetti Arianna , Brunetti Pietro , Pelotti Susi , Auwärter Volker 
Published: August 2022

AbstractIn the past years, new psychoactive substances (NPS) started circulating in prisons, leading to health risks and challenges for the criminal justice system. Seizures of papers and cards impregnated with synthetic cannabinoid (SCs) have been reported. In November 2021, a letter suspected to be drug‐infused was sent from a German prison to this laboratory. Toxicological analyses were performed by means of gas chromatography–mass spectrometry (GC–MS) for drug screening and liquid chromatography–tandem mass spectrometry (LC–MS/MS) as well as high‐performance (HP) LC with diode‐array detection (DAD) for semi‐quantification of the compounds. The novel synthetic opioid (NSO) AP‐237 was detected on the letter, with an estimated concentration of 1.2 μg/cm2, together with the SCs MDMB‐4en‐PINACA (77 μg/cm2) and 5F‐ADB (6.5 μg/cm2). To the best of the authors' knowledge, this is the first time an NSO was detected on a drug‐infused paper seized in a prison. Highly potent NSOs could easily be dissolved in organic solvents to produce impregnated papers and textiles, and this might represent a serious threat to the health of people in prison. Given the inhomogeneity in drug concentrations, health risks might in particular arise from the consumption of highly concentrated areas of the paper—so‐called “hot spots”—especially when highly potent NSOs are used for infusion. Laboratories engaged in analyzing such impregnated papers should be aware of the potential presence of NSOs and adapt the respective methods accordingly.
Disentangling direct and indirect effects of landscape structure on urban bird richness and functional diversity
Authors: Suárez‐Castro Andrés Felipe , Maron Martine , Mitchell Matthew G. E. , Rhodes Jonathan R. 
Published: August 2022

AbstractAs fragmented landscapes become increasingly common around the world, managing the spatial arrangement of landscape elements (i.e., landscape configuration) may help to promote the conservation of biodiversity. However, the relative effects of landscape configuration on different dimensions of biodiversity across species assemblages are largely unknown. Thus, a key challenge consists in understanding when it is necessary to focus on landscape configuration, in addition to landscape composition, to achieve multifunctional landscapes. We tested the effects of landscape composition (the percentage of tree cover and built infrastructure) and landscape configuration (degree of fragmentation) on landscape‐level species richness and different metrics of functional diversity of urban birds. We collected data on different bird guilds (nectarivores/frugivores, insectivores) from Brisbane, Australia. Using structural equation models, we found that landscape structure (landscape composition and configuration) affected functional diversity via two main pathways: (1) through effects of landscape composition, mediated by landscape configuration (indirect effects), and (2) through direct (“independent”) effects of landscape composition and configuration, filtering species with extreme trait values. Our results show that landscape‐level species richness declined with the extent of built infrastructure, but patterns of trait diversity did not necessarily correlate with this variable. Landscape configuration had a stronger mediating effect on some metrics of the functional diversity of insectivores than on the functional diversity of frugivores/nectarivores. In addition, fragmentation increased the effects of built infrastructure for some traits (body size and dispersal capacity), but not for others (habitat plasticity and foraging behavior). These results suggest that differential approaches to managing landscape structure are needed depending on whether the focus is on protecting functional diversity or species richness and what the target guild is. Managing landscape fragmentation in areas with high levels of built infrastructure is important if the objective is to protect insectivore species with uncommon traits, even if it is not possible to preserve high levels of species richness. However, if the target is to enhance both functional diversity and species richness of multiple guilds, the focus should be on improving composition through the reduction of negative effects of built infrastructure, rather than promoting specific landscape configurations in growing cities.
Integrating basic and applied research to estimate carnivore abundance
Authors: Sells Sarah N. , Podruzny Kevin M. , Nowak J. Joshua , Smucker Ty D. , Parks Tyler W. , Boyd Diane K. , Nelson Abigail A. , Lance Nathan J. , Inman Robert M. , Gude Justin A. , Bassing Sarah B. , Loonam Kenneth E. , Mitchell Michael S. 
Published: August 2022

AbstractA clear connection between basic research and applied management is often missing or difficult to discern. We present a case study of integration of basic research with applied management for estimating abundance of gray wolves (Canis lupus) in Montana, USA. Estimating wolf abundance is a key component of wolf management but is costly and time intensive as wolf populations continue to grow. We developed a multimodel approach using an occupancy model, mechanistic territory model, and empirical group size model to improve abundance estimates while reducing monitoring effort. Whereas field‐based wolf counts generally rely on costly, difficult‐to‐collect monitoring data, especially for larger areas or population sizes, our approach efficiently uses readily available wolf observation data and introduces models focused on biological mechanisms underlying territorial and social behavior. In a three‐part process, the occupancy model first estimates the extent of wolf distribution in Montana, based on environmental covariates and wolf observations. The spatially explicit mechanistic territory model predicts territory sizes using simple behavioral rules and data on prey resources, terrain ruggedness, and human density. Together, these models predict the number of packs. An empirical pack size model based on 14 years of data demonstrates that pack sizes are positively related to local densities of packs, and negatively related to terrain ruggedness, local mortalities, and intensity of harvest management. Total abundance estimates for given areas are derived by combining estimated numbers of packs and pack sizes. We estimated the Montana wolf population to be smallest in the first year of our study, with 91 packs and 654 wolves in 2007, followed by a population peak in 2011 with 1252 wolves. The population declined ~6% thereafter, coincident with implementation of legal harvest in Montana. Recent numbers have largely stabilized at an average of 191 packs and 1141 wolves from 2016 to 2020. This new approach accounts for biologically based, spatially explicit predictions of behavior to provide more accurate estimates of carnivore abundance at finer spatial scales. By integrating basic and applied research, our approach can therefore better inform decision‐making and meet management needs.
Predation thresholds for reintroduction of native avifauna following suppression of invasive Brown Treesnakes on Guam
Authors: McElderry Robert M. , Paxton Eben H. , Nguyen Andre V. , Siers Shane R. 
Published: August 2022

AbstractThe brown treesnake (BTS) (Boiga irregularis) invasion on Guåhan (in English, Guam) led to the extirpation of nearly all native forest birds. In recent years, methods have been developed to reduce BTS abundance on a landscape scale. To help assess the prospects for the successful reintroduction of native birds to Guåhan following BTS suppression, we modeled bird population persistence based on their life history characteristics and relative sensitivity to BTS predation. We constructed individual‐based models and simulated BTS predation in hypothetical founding populations for each of seven candidate bird species. We represented BTS predation risk in two steps: risk of being encountered and risk of mortality if encountered. We link encounter risk from the bird's perspective to snake contact rates at camera traps with live animal lures, the most direct practical means of estimating BTS predation risk. Our simulations support the well‐documented fact that Guåhan's birds cannot persist with an uncontrolled population of BTS but do indicate that bird persistence in Guåhan's forests is possible with suppression short of total eradication. We estimate threshold BTS contact rates would need to be below 0.0002–0.0006 snake contacts per bird per night for these birds to persist on the landscape, which translates to an annual encounter probability of 0.07–0.20. We simulated the effects of snake‐proof nest boxes for Sihek (Todiramphus cinnamominus) and Såli (Aplonis opaca), but the benefits were small relative to the overall variation in contact rate thresholds among species. This variation among focal bird species in sustainable predation levels can be used to prioritize species for reintroduction in a BTS‐suppressed landscape, but variation among these species is narrow relative to the required reduction from current BTS levels, which may be four orders of magnitude higher (>0.18). Our modeling indicates that the required predation thresholds may need to be lower than have yet been demonstrated with current BTS management. Our predation threshold metric provides an important management tool to help estimate target BTS suppression levels that can be used to determine when bird reintroduction campaigns might begin and serves as a model for other systems to match predator control with reintroduction efforts.
Climatic history, constraints, and the plasticity of phytochemical traits under water stress
Authors: Diethelm Aramee C. , Reichelt Michael , Dilts Thomas E. , Farlin James P. , Marlar Audrey , Pringle Elizabeth G. 
Published: August 2022

AbstractEnvironmental stress can induce changes in organismal traits and in resulting intraspecific variation. The nature of such effects will depend on the plasticity of trait expression and on any ecological constraints to such expression. Plants can mitigate abiotic stress, like drought, by changing their chemistry, but the ability to induce costly metabolites may be under strong local selection and ecologically constrained. Here, we asked whether climate at the seed source predicts plant chemical plasticity in response to water stress and what the consequences are for intraspecific variation in phytochemical traits. To this end, we used common gardens of two widespread species of western milkweed (Asclepias fascicularis and Asclepias speciosa) that had been collected from sites across an aridity gradient. Both species produce high concentrations of leaf flavonols, which are hypothesized to mitigate water stress by functioning as antioxidants. These compounds were found in higher constitutive concentrations in plants sourced from drier sites, and both species responded to water stress in the common garden by increasing leaf flavonol concentrations. Interestingly, flavonol plasticity was higher in plants sourced from wetter sites in A. fascicularis, with similar, but weaker, patterns in A. speciosa. These opposing patterns in constitutive and induced flavonol expression reduced the variation between populations in leaf flavonol concentrations under water stress. These results suggest that local adaptation in plants can shape phytochemical strategies for water limitation but that the cost of metabolite production may ultimately limit the range of phytochemical variation.
Reestablishing a foundational species: Limitations on post‐wildfire sagebrush seedling establishment
Authors: Arkle Robert S. , Pilliod David S. , Germino Matthew J. , Jeffries Michelle I. , Welty Justin L. 
Published: August 2022

AbstractImproving post‐wildfire restoration of foundational plant species is crucial for conserving imperiled ecosystems. We sought to better understand the initial establishment of sagebrush (Artemisia sp.), a foundational shrubland species over a vast area of western North America, in the first 1–2 years post‐wildfire, a critical time period for population recovery. Field data from 460 sagebrush populations sampled across the Great Basin revealed several patterns. Sagebrush seedlings were uncommon in the first 1–2 years after fire, with none detected in 69% of plots, largely because most fires occurred in areas of low resistance to invasive species and resilience to disturbance (hereafter, R&R). Post‐fire aerial seeding of sagebrush dramatically increased seedling occupancy, especially in low R&R areas, which exhibited a 3.4‐fold increase in occupancy over similar unseeded locations. However, occupancy models and repeat surveys suggested exceptionally high mortality, as occupancy rates declined by as much as 50% between the first and second years after fire. We found the prevalence of “fertile island” microsites (patches beneath fire‐consumed sagebrush) to be the best predictor of seedling occupancy, followed by aerial seeding status, native perennial grass cover, and years since fire. In populations where no sagebrush seeding occurred, seedlings were most likely to occur in locations with a combination of high fertile island microsite cover and close proximity to a remnant sagebrush plant. These important attributes were only present in 13% of post‐fire locations, making them rare across the Great Basin. Finally, in the absence of fertile islands and remnant plants, seedling establishment was not observed in any unseeded areas, and rarely in seeded locations. Thus, local extirpation of sagebrush could have important, long‐term implications for sagebrush reestablishment following future fires if there are no mature individuals to leave behind fertile islands or serve as remnant individuals. These findings highlight the importance of landscape legacy effects and could help guide where and how big sagebrush restoration is conducted in the future.