bluuebunny/crossref_metadata_2025_split huggingface dataset:
Keel-bone fractures are associated with bone quality differences in laying hens
Authors: Wei HD , Chen YJ , Zeng XY , Bi YJ , Wang YN , Zhao S , Li JH , Li X , Zhang RX , Bao J 
Published: January 2021

AbstractThis study aimed to investigate the relationship between bone quality in terms of metabolism, homeostasis of elements, bone mineral density (BMD), and microstructure and keel-bone fractures in laying hens (Gallus gallus domesticus). One hundred and twenty 17 week old Lohmann White laying hens with normal keel bones were individually housed in furnished cages for 25 weeks. Birds were then euthanased and dissected to assess keel-bone status at 42 weeks. Serum and keel-bone samples from normal keel (NK) and fractured keel (FK) hens were collected to determine the previously mentioned bone quality parameters. The results showed FK hens to have higher levels of the components of osteocalcin, greater alkaline phosphatase activity in serum and keel bones, and greater tartrate-resistant acid phosphatase (TRAP) activity in keel bones, compared to NK hens. Additionally, FK hens also had higher concentrations of Li, B, K, Cu, As, Se, Sn, Hg, and Pb, but lower concentrations of Na, P, and Ca. Moreover, FK hens showed decreased bone microstructural parameters including bone volume/tissue volume, trabecular number, degree of anisotropy, connectivity density, and BMD, but increased trabecular separation. Meanwhile, no differences were detected in serum TRAP activity, trabecular thickness, bone surface, or bone surface/bone volume. Results showed laying hens with keel-bone fractures to have differences in bone metabolism, elements of home-ostasis, bone microstructure parameters, and BMD. These results suggest that keel-bone fractures may be associated with bone quality.
Identification of suitable reference genes for studies of Syringa pinnatifolia Hemsl.
Authors: Gao Jiaqi , Liu Juan , Jiang Chao , Chen Suyile , Huang Luqi 
Published: January 2021

Syringa pinnatifolia Hemsl. (Oleaceae) is a species of shrub with a limited distribution in China. Several chemical compounds with pharmacological effects have been isolated from S. pinnatifolia, including new lignans and sesquiterpenes. Studies of gene expression in this species require the identification of suitable reference genes that are stably expressed under different conditions and in different tissues. To identify candidate reference genes, here we used the geNorm, NormFinder, and BestKeeper algorithms to analyze the stability of 12 candidate genes. The geometric mean of the rankings generated with these algorithms was used to obtain a comprehensive ranking. TBP and PP2A were found to be appropriate reference genes for calli treated with different external stimuli, and TIP41 and TBP were found to be appropriate reference genes in differentiated tissues. When calli and differentiated tissues were considered together, TBP and TIP41 were found to be the most reliable reference genes. The selected genes were validated by analysis of HMGR expression in calli and differentiated tissues. This study is the first to screen candidate reference genes in the genus Syringa and could help guide future molecular studies in this genus.
High Performance Core/Shell Ni/Ni(OH)2 Electrospun Nanofiber Anodes for Decoupled Water Splitting
Authors: Landman Avigail , Hadash Shabtai , Shter Gennady E. , Ben‐Azaria Alon , Dotan Hen , Rothschild Avner , Grader Gideon S. 
Published: January 2021

AbstractDecoupled water splitting is a promising new path for renewable hydrogen production, offering many potential advantages such as stable operation under partial‐load conditions, high‐pressure hydrogen production, overall system robustness, and higher safety levels. Here, the performance of electrospun core/shell nickel/nickel hydroxide anodes is demonstrated in an electrochemical‐thermally activated chemical decoupled water splitting process. The high surface area of the hierarchical porous electrode structure improves the utilization efficiency, charge capacity, and current density of the redox anode while maintaining high process efficiency. The anodes reach average current densities as high as 113 mA cm−2 at a working potential of 1.48 VRHE and 64 mA cm−2 at 1.43 VRHE, with a Faradaic efficiency of nearly 100% and no H2/O2 intermixing in a membrane‐free cell.
Ultra‐Robust Flexible Electronics by Laser‐Driven Polymer‐Nanomaterials Integration
Authors: Rodriguez Raul D. , Shchadenko Sergey , Murastov Gennadiy , Lipovka Anna , Fatkullin Maxim , Petrov Ilia , Tran Tuan‐Hoang , Khalelov Alimzhan , Saqib Muhammad , Villa Nelson E. , Bogoslovskiy Vladimir , Wang Yan , Hu Chang‐Gang , Zinovyev Alexey , Sheng Wenbo , Chen Jin‐Ju , Amin Ihsan , Sheremet Evgeniya 
Published: January 2021

AbstractPolyethylene terephthalate (PET) is the most widely used polymer in the world. For the first time, the laser‐driven integration of aluminum nanoparticles (Al NPs) into PET to realize a laser‐induced graphene/Al NPs/polymer composite, which demonstrates excellent toughness and high electrical conductivity with the formation of aluminum carbide into the polymer is shown. The conductive structures show an impressive mechanical resistance against >10000 bending cycles, projectile impact, hammering, abrasion, and structural and chemical stability when in contact with different solvents (ethanol, water, and aqueous electrolytes). Devices including thermal heaters, carbon electrodes for energy storage, electrochemical and bending sensors show this technology's practical application for ultra‐robust polymer electronics. This laser‐based technology can be extended to integrating other nanomaterials and create hybrid graphene‐based structures with excellent properties in a wide range of flexible electronics’ applications.
Molecular Size Matters: Ultrafast Dye Singlet Sensitization Pathways to Bright Nanoparticle Emission
Authors: Liu Jing , Geiregat Pieter , Pilia Luca , Van Deun Rik , Artizzu Flavia 
Published: January 2021

AbstractDye‐sensitized luminescent lanthanide (Ln)‐based nanoparticles enable broad applications spanning from fluorescent microscopy to biological therapy. However, the limited understanding of the dye→Ln3+ sensitization process still leaves ample room for the improvement of its efficiency. In this work, a unique combination of photoluminescence and transient absorption spectroscopy is employed to reveal the hereto hidden dye→Ln3+ or dye→Ln13+→Ln23+ energy transfer pathways in the ultrafast time scale. Steady‐state and time‐resolved data, supported by density functional theory calculations, demonstrate that Ln3+ sensitization is realized directly from the singlet excited state of dye molecules and is strictly regulated by a distance‐dependent regime overcoming the role of the donor–acceptor spectral overlap for the size and geometry of dye molecules. It is shown that exceptionally high efficiency is achieved by judiciously selecting small‐sized dye molecules with localized molecular orbitals sitting close (<0.5 nm) to the nanoparticle surface. This new understanding will enable a rational design of dye‐sensitized Ln nanoparticles allowing for a dramatic improvement of the emission efficiency in a variety of nanomaterials for light conversion.
Spontaneous Radiation Amplification in a Microsphere‐Coupled CsPbBr3 Perovskite Vertical Structure
Authors: Yan Yinzhou , Yang Lixue , Liu Wei , Wang Qiang , Li Sijia , Xu Chunxiang 
Published: January 2021

AbstractMicrosphere (MS) cavities hold great potential in nanophotonics due to their extraordinary optical properties. All‐inorganic trihalide perovskites with high environmental stability and easy‐for‐preparation have shown great promise for the next‐generation optoelectronic nanodevices. Unfortunately, the nonradiative recombination of exciton is inevitably aggravating the photoluminescence quantum yields (PLQYs). Here, a microsphere‐coupled CsPbBr3 perovskite vertical structure is proposed for amplification of spontaneous radiation (SR) up to 190‐fold. The mechanisms of SR amplification by an MS cavity are completely revealed, for the first time, including Mie focusing (MF) for energy harvesting, directional antenna (DA) for emission convergence, and whispering‐gallery modes (WGMs) for regulation of exciton dynamics. The temperature‐dependent photoluminescence (PL) spectra clarify the contributions of WGMs for the boosting of SR decay and suppression of exciton–phonon interactions for giant PL enhancement. Furthermore, a straightforward approach is presented for a selective MS array capped on a perovskite microcrystal (PeMC) film as a vertical structure for patterned PL enhancement. The excitation‐power‐ and excitation‐observation‐angle‐dependent luminescence contrast inspire a novel anticounterfeiting strategy. The vertical architecture not only advances the understanding of microcavity‐based SR amplification from PeMCs, but also offers opportunities to facilitate the synergistic manipulation of optical fields and exciton–phonon interactions for developing high‐efficient optoelectronic devices.
Recent Progress in Palladium‐Catalyzed Radical Reactions
Authors: Sun Xi , Dong Xu , Liu Hui , Liu Yuying 
Published: January 2021

AbstractIn recent years, great improvements have been made on palladium‐catalyzed radical reactions. Emerging elegant methodologies of radical involved palladium‐catalyzed transformations provide more and more effective strategies for the construction of complex heterocyclic compounds and applications in drug discovery. It is universally known that Pd(0)/(II)/(IV)‐mediated reactions usually undergo two‐electron transfer processes, while the Pd(I) and Pd(III) involved reactions usually occur via single electron transfer processes. Since our review on palladium radical was published, numurous methodolgies involving palladium radical have sprung up in the past five years. This review further summarized the up‐to‐date transformations toward palladium radical from 2015. For most of these catalytic cycles strategies, plausible mechanisms are demonstrated in detail to give better insight for chemists in need.magnified image
Rh(III)‐Catalyzed Csp2−Csp3 Bond Cleavage/Carbonylethylation of α‐Indolyl Alcohols
Authors: Liu Zhipeng , Hu Xinwei , Yang Can , Xie Haisheng , Jiang Huanfeng , Zeng Wei 
Published: January 2021

AbstractA Rh(III)‐catalyzed Csp2−Csp3 bond cleavage/carbonylethylation of α‐indolyl alcohols with allylic alcohols has been reported. This transformation involved a cascade C−C bond cleavage/C−C bond formation, and provides a novel approach to assemble 2‐carbonylethylindole skeletons.magnified image
Visible Light‐Promoted Selenylation/Cyclization of Enaminones toward the Formation of 3‐Selanyl‐4H‐Chromen‐4‐Ones
Authors: Liu Hao‐Yang , Zhang Jia‐Rong , Huang Guo‐Bao , Zhou Yi‐Huan , Chen Yan‐Yan , Xu Yan‐Li 
Published: January 2021

AbstractA simple and efficient visible‐light‐promoted selenylation/cyclization of enaminones have been realized for the practical synthesis of 3‐selanyl‐4H‐chromen‐4‐ones. This reaction is performed in the mild conditions, no transition metal catalyst or photocatalysts and no additional oxidants are required. In addition, the 3‐selanyl‐4H‐chromen‐4‐ones could be easily converted to selanyl‐functionalized pyrimidines by reacting with benzamidine substrates.magnified image
Zirconium Oxide‐Catalyzed Direct Amidation of Unactivated Esters under Continuous‐Flow Conditions
Authors: Rashed Md. Nurnobi , Masuda Koichiro , Ichitsuka Tomohiro , Koumura Nagatoshi , Sato Kazuhiko , Kobayashi Shū 
Published: January 2021

AbstractA sustainable and environmentally benign direct amidation reaction of unactivated esters with amines has been developed in a continuous‐flow system. A commercially available amorphous zirconium oxide was found to be an efficient catalyst for this reaction. While the typical amidation of esters with amines requires a stoichiometric amount of a promoter or metal activator, the present continuous‐flow method enabled the direct amidation reaction under additive‐free conditions with an extensive diversity towards various functional groups. High yields of the products were obtained with a nearly equimolar proportion of starting materials to reduce byproduct formation, which renders this process applicable for use in a sequential‐flow system.magnified image
Nanoparticles as contrast agents for photoacoustic brain imaging
Authors: Liu Xingang , Duan Yukun , Liu Bin 
Published: January 2021

AbstractPhotoacoustic (PA) imaging has emerged as a promising technique for real‐time detection and diagnosis of brain‐related pathologies, due to its advantages in deep penetration of ultrasound imaging and high resolution of optical fluorescence imaging. We herein provide an overview on the latest developments of nanoparticles as contrast agents specifically designed for PA imaging of brain tumor, and brain vascular and other brain‐related diseases. Five design considerations of high‐performance PA contrast agents for brain‐related disease diagnosis are discussed, which include (1) strong absorption in NIR or NIR‐II window, (2) good biocompatibility, (3) high photothermal conversion efficiency, (4) precise nanostructure control, and (5) specific targeting capability. Challenges and perspectives of developing more robust and universal contrast agents for enhanced PA imaging are discussed at the end.
Modeling a fluidized bed reactor by integrating various scales: Pore, particle, and reactor
Authors: Macías Robert J. , Maya Juan C. , Chejne Farid , Afailal Z. , Arauzo J. 
Published: January 2021

AbstractThis work proposes a novel population‐balance based model for a bubbling fluidized bed reactor. This model considers two continuum phases: bubble and emulsion. The evolution of the bubble size distribution was modeled using a population balance, considering both axial and radial motion. This sub‐model involves a new mathematical form for the aggregation frequency, which predicts the migration of bubbles from the reactor wall toward the reactor center. Additionally, reacting particles were considered as a Lagrangian phase, which exchanges mass with emulsion phases. For each particle, the variation of the pore size distribution was also considered. The model presented here accurately predicted the experimental data for biochar gasification in a lab‐scale bubbling fluidized bed reactor. Finally, the aggregation frequency is shown to serve as a scaling parameter.
Mechanistic Understanding of Base‐Catalyzed Aldimine/Ketoamine Condensations: An Old Story and A New Model
Authors: Li Zhe‐wei , Zhang Lin , Pu Min , Lei Ming 
Published: January 2021

AbstractAldimine/ketoamine condensations are basic reactions in chemical synthesis. Herein a density functional theory (DFT) study was performed to characterize the mechanism of the ketoamine condensation of acetophenone with tert‐butanesulfinamide catalyzed by NaOH. The calculated results showed that the main N‐tert‐butanesulfinimines products own E configuration, which are due to both thermodynamic and kinetic effects. Meanwhile, the key roles of the substrate cage and the synergistic catalytic mode formed by metal cation and hydroxyl anion were pointed out, which imply the influence of noncovalent interactions on reaction activity. This theoretical study revealed the origin of E sulfinimines achieved in aldimine/ketoamine condensations catalyzed by base, which could provide new insights into the nature for the condensation reactions.
A dense sample of fossil primates (Adapiformes, Notharctidae, Notharctinae) from the Early Eocene Willwood Formation, Wyoming: Documentation of gradual change in tooth area and shape through time
Authors: O'Leary Maureen A. 
Published: January 2021

AbstractObjectivesThe Willwood Formation of the southern Bighorn Basin, Wyoming is a fluvial rock sequence that spans approximately 3 million years of early Eocene time. It has yielded one the largest collections of fossil mammals in the world including thousands of dentitions of extinct lemur‐like primates known as notharctines. In the southern Bighorn Basin, specimens of these primates have been collected on numerous paleontological expeditions and the stratigraphic levels yielding the dentitions have been carefully recorded. Notharctine dentitions represent a rare opportunity to study morphological variation in a single anatomical system through time among closely related individuals.Materials and MethodsPrior studies of Bighorn Basin notharctines through time produced measurements of hundreds of specimens but I report here results from measurement and comparison of the dentitions and dentaries of more than 3,000 specimens, all stratigraphically mapped.ResultsVariation in premolar and molar area and variation in dentary depth are apparent throughout the section. Specimens with relatively small teeth and dentaries are known from the older part of the section. In younger rocks, variation in tooth area among specimens increases. Variation in tooth area is continuous and overlaps extensively both within and between stratigraphic levels. Other dental variables examined by inspection change in a mosaic and continuous fashion through the section. These features include variation in the presence and number of paraconids on the lower fourth premolar (p4), the size and shape of the entoconid notch on the lower first and second molars, and the relative development of the pseudohypocone, mesostyle, and cingula on the upper molars.DiscussionThese broad patterns can be identified despite notharctine alpha taxonomy being in need of extensive revision and, importantly, simplification. Such revision is beyond the scope of this article but is essential if we are to develop a taxonomy that is both free of stratigraphic influence and useful for rapid, repeatable species assignment. Boundaries among the patterns of tokogenesis, anagenesis, and cladogenesis are blurred in this dense sample of extinct primates. While pattern of evolution, a population‐level phenomenon, may be difficult to falsify in the fossil record, this notharctine sample suggests that in the rare instance such as this, when the fossil record is densely sampled, change through time is continuous and more consistent with gradual evolution.
Comparing semi‐landmarking approaches for analyzing three‐dimensional cranial morphology
Authors: Rolfe Sara , Davis Christopher , Maga A. Murat 
Published: January 2021

AbstractObjectivesIncreased use of three‐dimensional (3D) imaging data has led to a need for methods capable of capturing rich shape descriptions. Semi‐landmarks have been demonstrated to increase shape information but placement in 3D can be time consuming, computationally expensive, or may introduce artifacts. This study implements and compares three strategies to more densely sample a 3D image surface.Materials and methodsThree dense sampling strategies: patch, patch‐thin‐plate spline (TPS), and pseudo‐landmark sampling, are implemented to analyze skulls from three species of great apes. To evaluate the shape information added by each strategy, the semi or pseudo‐landmarks are used to estimate a transform between an individual and the population average template. The average mean root squared error between the transformed mesh and the template is used to quantify the success of the transform.ResultsThe landmark sets generated by each method result in estimates of the template that on average were comparable or exceeded the accuracy of using manual landmarks alone. The patch method demonstrates the most sensitivity to noise and missing data, resulting in outliers with large deviations in the mean shape estimates. Patch‐TPS and pseudo‐landmarking provide more robust performance in the presence of noise and variability in the dataset.ConclusionsEach landmarking strategy was capable of producing shape estimations of the population average templates that were generally comparable to manual landmarks alone while greatly increasing the density of the shape information. This study highlights the potential trade‐offs between correspondence of the semi‐landmark points, consistent point spacing, sample coverage, repeatability, and computational time.
Giant Optical Activity and Second Harmonic Generation in 2D Hybrid Copper Halides
Authors: Guo Zhihang , Li Junzi , Wang Changshun , Liu Rulin , Liang Jiechun , Gao Yang , Cheng Jiaji , Zhang Wenjing , Zhu Xi , Pan Ruikun , He Tingchao 
Published: January 2021

AbstractHybrid organic–inorganic metal halides have emerged as highly promising materials for a wide range of applications in optoelectronics. Incorporating chiral organic molecules into metal halides enables the extension of their unique optical and electronic properties to chiral optics. By using chiral (R)‐ or (S)‐methylbenzylamine (R‐/S‐MBA) as the organic component, we synthesized chiral hybrid copper halides, (R‐/S‐MBA)2CuCl4, and investigated their optical activity. Thin films of this material showed a record anisotropic g‐factor as high as approximately 0.06. We discuss the origin of the giant optical activity observed in (R‐/S‐MBA)2CuCl4 by theoretical modeling based on density functional theory (DFT) and demonstrate highly efficient second harmonic generation (SHG) in these samples. Our study provides insight into the design of chiral materials by structural engineering, creating a new platform for chiral and nonlinear photonic device applications of the chiral hybrid copper halides.
Covalent Organic Frameworks Enabling Site Isolation of Viologen‐Derived Electron‐Transfer Mediators for Stable Photocatalytic Hydrogen Evolution
Authors: Mi Zhen , Zhou Ting , Weng Weijun , Unruangsri Junjuda , Hu Ke , Yang Wuli , Wang Changchun , Zhang Kai A. I. , Guo Jia 
Published: January 2021

AbstractElectron transfer is the rate‐limiting step in photocatalytic water splitting. Viologen and its derivatives are able to act as electron‐transfer mediators (ETMs) to facilitate the rapid electron transfer from photosensitizers to active sites. Nevertheless, the electron‐transfer ability often suffers from the formation of a stable dipole structure through the coupling between cationic‐radical‐containing viologen‐derived ETMs, by which the electron‐transfer process becomes restricted. Herein, cyclic diquats, a kind of viologen‐derived ETM, are integrated into a 2,2′‐bipyridine‐based covalent organic framework (COF) through a post‐quaternization reaction. The content and distribution of embedded diquat‐ETMs are elaborately controlled, leading to the favorable site‐isolated arrangement. The resulting materials integrate the photosensitizing units and ETMs into one system, exhibiting the enhanced hydrogen evolution rate (34600 μmol h−1 g−1) and sustained performances when compared to a single‐module COF and a COF/ETM mixture. The integration strategy applied in a 2D COF platform promotes the consecutive electron transfer in photochemical processes through the multi‐component cooperation.
Chiral Near‐Infrared Fluorophores by Self‐Promoted Oxidative Coupling of Cationic Helicenes with Amines/Enamines
Authors: Bosson Johann , Labrador Geraldine M. , Besnard Céline , Jacquemin Denis , Lacour Jérôme 
Published: January 2021

AbstractIn one pot, tertiary alkyl amines are oxidized to enamines by cationic dioxa[6]helicene, which further reacts as electrophile and oxidant to form mono or bis donor‐π‐acceptor coupling products. This original and convergent synthetic approach provides a strong extension of conjugation yielding chromophores that absorb intensively in far‐red or NIR domains (λmax up to 791 nm) and fluoresce in the NIR as well (λmax up to 887 nm). Intense ECD properties around 790 nm with a |Δϵ| value up to 60 M−1 cm−1 are observed.