bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Synthesis of Red‐Emitting Sr2Sc0.5Ga1.5O5:Eu2+ Phosphors and the Tunable Photoluminescence Via Sr/Ba Substitution
Authors: Yang Zhiyu , Zhou Yayun , Qiao Jianwei , Molokeev Maxim S. , Xia Zhiguo 
Published: May 2021

AbstractDiscovering new Eu2+‐doped red‐emitting phosphors in oxide‐based materials is a challenge for white light‐emitting diode (WLED) applications. Herein, a highly efficient high‐frequency induction heating method is employed to rapidly prepare the red‐emitting Sr2Sc0.5Ga1.5O5:Eu2+ phosphors peaking at 614 nm and exhibiting a high photoluminescence quantum yield of 78.4% under the excitation of 440 nm. The structural and spectral analyses suggest that Eu2+ ions tend to enter the [Sc1/Ga1O6] and [Ga2O6] polyhedrons with small coordination numbers, leading to the broadband red emission originated from large crystal field splitting of Eu2+ 5d level. The chemical substitution of Ba in the Sr site enhances the thermal stability and helps to the photoluminescence tuning from 614 to 728 nm in SrBaSc0.5Ga1.5O5:Eu2+. The WLED device fabricated by blending the red Sr1.7Ba0.3Sc0.5Ga1.5O5:Eu2+ and yellow Y3(Al, Ga)5O12:Ce3+ phosphors shows a high color‐rendering index (Ra = 91.1), and low color‐correlated temperature (CCT = 4750 K). This study aims to provide a new synthesis method and design principle for guiding the development of Eu2+‐doped oxide‐based red phosphors with low preparation cost; moreover, the photoluminescence tuning strategy via cation substitutions is essential to achieve tunable emission, even the near‐infrared luminescence.
Ultrafast Nanoscale Gradient Junction Self‐Powered Schottky Photodetectors for Vision‐Like Object Classification
Authors: Kumar Mohit , Lim Jaeseong , Park Ji‐Yong , Kim Sangwan , Seo Hyungtak 
Published: May 2021

AbstractEmulating human vision for pattern classification is essential in intelligent machines, including pilotless vehicles and humanoid robots. Traditionally, analog visual information is captured by photosensors, which are sequentially classified using a physically separated algorithm‐based unit, such as a computer. Among such units, a self‐powered photodetector with a quick information sensing feature can be utilized for an unprecedented pattern classification; however, designing an ultrafast photodetector while maintaining a high sensitivity is critical. Herein, an alternative photovoltaic‐effect‐based, highly sensitive, self‐powered, broadband, ultrafast gradient junction nanoscale Schottky photodetector is introduced, that can sense input optical information without latency. Importantly, the proposed device can sense optical input within a ≈40 ns duration and demonstrate a 3‐dB bandwidth wider than 0.5 MHz, providing a throughput of 10 million bits per second. Photoconductive atomic force microscopy and Kelvin probe force microscopy independently revealed the photodynamic characteristic at a nanometer (≈35 nm) scale. Further, an array that can classify nontrivial patterns even with noisy inputs is developed. A unique solution to achieve an ultrafast photo response in self‐powered mode and classify the input patterns is provided. The proposed approach can be extended to several other artificial neural sensors, such as tactile, audio, and thermal sensors.
From Centrosymmetry to Noncentrosymmetry: Tailoring the Structural Arrangements of Carbonates with Strong Nonlinear Optical Response through Partial Anion Substitution
Authors: Meng Xianghe , Gong Pifu , Tang Chunlan , Yin Wenlong , Lin Zheshuai , Xia Mingjun 
Published: May 2021

AbstractSecond‐harmonic nonlinear‐optical (NLO) crystals with intrinsically noncentrosymmetric (NCS) structures are the core crystalline materials in the modern optics and laser technology. Here, taking as‐grown centrosymmetric NaY(CO3)2 and NCS YOHCO3 crystals as an example, a partial anion substitution strategy in the carbonate system is provided to develop NLO materials with remarkable NLO property for the first time, while the outstanding linear optical properties such as wide bandgap and large birefringence are maintained. Notably, benefiting from the planar π‐conjugated (CO3)2− anions and closed shell electronic structure of Y3+ cations, the YOHCO3 crystal simultaneously manifests a deep UV cutoff (<200 nm), sturdy second‐harmonic‐generation signal (2 × KH2PO4), and gigantic birefringence (0.07 at 1064 nm), enabling phase‐matching in short‐wavelength UV region. In addition, first‐principles calculations are conducted for the in‐depth analysis on the structure–optical property connection.
Regioselective Synthesis of Emission Color‐Tunable Pyrazolo[1,5‐a]pyrimidines with β,β‐Difluoro Peroxides as 1,3‐Bis‐Electrophiles
Authors: Ma Yangyang , Chen Yuanjin , Lv Leiyang , Li Zhiping 
Published: May 2021

AbstractThe synthesis and photophysical properties of fluorescent pyrazolo[1,5‐a]pyrimidines (PPs) are explored. An array of 5,7‐disubstituted fluorescent PPs are prepared selectively by using β,β‐difluoro peroxides as the 1,3‐bis‐electrophiles. The synthesized PPs display a fairly significant stokes shift (up to 211 nm) and a large window of tunable emission wavelength that covers most of the visible spectrum (400 nm to 800 nm). Theoretical calculation indicates that the distinguished variation of intramolecular charge transfer (ICT) ability upon the varied substituents is responsible for the color‐tunable fluorescence emission.magnified image
A Photoinduced Multicomponent Regioselective Synthesis of 1,4,5‐Trisubstituted‐1,2,3‐Triazoles: Transition Metal‐, Azide‐ and Oxidant‐Free Protocol
Authors: Sai Allaka Bhargava , Basavoju Srinivas , Rama Krishna Gamidi 
Published: May 2021

AbstractA transition metal‐ and azide‐free approach is explored to synthesize 1,4,5‐trisubstituted‐1,2,3‐triazoles under sunlight. The reaction proceeds via C−N and N−N bond formations. These regioselective 1,2,3‐triazoles are obtained from isatin Schiff bases, benzaldehydes and tosylhydrazine in the presence of base. This protocol offers the structurally diverse 1,2,3‐triazole derivatives with 75–90% yields.magnified image
Using a browntop millet companion crop to aid native grass establishment
Authors: Richwine Jonathan D. , Keyser Patrick D. , Hancock Dennis W. , Ashworth Amanda J. 
Published: May 2021

AbstractThe lack of forage production during the seedling year is a barrier to wide‐scale adoption of native warm‐season grasses (NWSG). To address this, two NWSG establishment experiments were conducted in Knoxville, TN, 2016–2018, to determine the efficacy of big bluestem (BB; Andropogon gerardii Vitman) and switchgrass (SG; Panicum virgatum L.) establishment with browntop millet [BTM; Urochloa ramosa (L.) Nguyen] as a companion crop. Each experiment was a randomized complete block arranged as a 2 × 3 factorial. Two defoliation strategies [(1) harvests based on BTM maturity (boot to heading stage) for hay (HAY) or (2) clipping to control BTM competition by maintaining >50% sunlight reaching BB and SG seedlings (CLIP)] were coupled with three BTM seeding rates [0 (control), 11.2 (half‐recommended rate), and 22.4 (full‐recommended rate) kg pure live seed (PLS) ha−1]. Only BTM seeding rate affected BB and SG plant density at dormancy. In all cases, the control had greater BB and SG plant density than the full‐recommended rate, indicating that BTM impeded BB and SG establishment. All BTM seeding rates resulted in acceptable stands (≥5.4 plants m−2) of BB (both years) and SG (2017 only). Only the control allowed for acceptable stands of SG in 2016 (8.5 plants m−2). Managing BTM for HAY produced a mean cumulative dry matter (DM) yield of 3.15 and 2.68 Mg ha−1 in 2016 and 2017, respectively. These findings show that BTM can be a companion crop that helps offset production losses during BB and SG establishment.
The mechanisms of vascular aging
Authors: Wang Shan , Hu Song , Mao Yongjun 
Published: May 2021

AbstractVascular senescence is one of the hotspots in current research. With global average life expectancy increasing, delaying or reducing aging and age‐related diseases has become a pressing issue for improving quality of life. Vascular senescence is an independent risk factor for age‐related cardiovascular diseases (CVD) and results in the deterioration of CVD. Nevertheless, the underlying mechanisms of the vascular senescence have not been expressly illustrated. In this review, we attempt to summarize the recent literature in the field and discuss the major mechanisms involved in vascular senescence. We also underline key molecular aspects of aging‐associated vascular dysfunction in the attempt to highlight potential innovative therapeutic targets to delay the onset of age‐related diseases.
Multistage adaptive stochastic mixed integer optimization under endogenous and exogenous uncertainty
Authors: Motamed Nasab Farough , Li Zukui 
Published: May 2021

AbstractTo solve multistage adaptive stochastic optimization problems under both endogenous and exogenous uncertainty, a novel solution framework based on robust optimization technique is proposed. The endogenous uncertainty is modeled as scenarios based on an uncertainty set partitioning method. For each scenario, the adaptive binary decision is assumed constant and the continuous variable is approximated by a function linearly dependent on endogenous uncertain parameters. The exogenous uncertainty is modeled using lifting methods. The adaptive decisions are approximated using affine functions of the lifted uncertain parameters. In order to demonstrate the applicability of the proposed framework, a number of numerical examples of different complexity are studied and a case study for infrastructure and production planning of shale gas field development are presented. The results show that the proposed framework can effectively solve multistage adaptive stochastic optimization problems under both types of uncertainty.
A prediction model for the critical gas velocity and pressure gradient of continuous liquid‐carrying in inclined pipes
Authors: Wang Wu‐Jie , Cui Guo‐Min , Xiao Yuan , Chen Jia‐Xing 
Published: May 2021

AbstractA generic model for the prediction of critical gas velocity and pressure gradient in slightly inclined pipes (β ≤ 6°) is presented in this article. The gas–liquid configuration was determined based on the minimum energy principle and consideration of wettability and surface tension. A visualization experiment was conducted to obtain the critical gas velocity and the critical pressure gradient of a gas–liquid flow through the 40 and 60‐mm pipe diameter. The theoretical study shows that the configuration is close to a convex interface shape at the critical conditions, which is in accord with the experimental phenomenon. Experimental study shows interfacial waves are the main cause of increased interfacial friction factor and a linear functional relationship between the inclination angle and the flow correction factor f(β). The results demonstrate that the new model is capable of providing satisfactory prediction results for the critical gas velocity, pressure drop, and liquid holdup.
Bootstrap aggregation accuracy gains in nearest‐neighbor nowcasting of Swedish gross domestic product
Authors: Jönsson Kristian 
Published: May 2021

AbstractThis article investigates the accuracy gains that can be made by applying bootstrap aggregation to K nearest‐neighbor nowcasting of Swedish gross domestic product. Using both a simulation‐based approach and a theoretical approach, the results indicate that substantial nowcasting accuracy gains can be made using bootstrap aggregation when considering one neighbor in the nowcasting algorithm, that is, when K = 1. Furthermore, a comparison of the simulation‐based and theoretical approaches to bootstrap aggregation indicates that using as few as 25 bootstrap replications can carry, in expectation, the simulation‐based results close to the theoretical results.
Comprehensive phenotyping of erythropoiesis in human bone marrow: Evaluation of normal and ineffective erythropoiesis
Authors: Yan Hongxia , Ali Abdullah , Blanc Lionel , Narla Anupama , Lane Joseph M. , Gao Erjing , Papoin Julien , Hale John , Hillyer Christopher D. , Taylor Naomi , Gallagher Patrick G. , Raza Azra , Kinet Sandrina , Mohandas Narla 
Published: May 2021

AbstractIdentification of stage‐specific erythroid cells is critical for studies of normal and disordered human erythropoiesis. While immunophenotypic strategies have previously been developed to identify cells at each stage of terminal erythroid differentiation, erythroid progenitors are currently defined very broadly. Refined strategies to identify and characterize BFU‐E and CFU‐E subsets are critically needed. To address this unmet need, a flow cytometry‐based technique was developed that combines the established surface markers CD34 and CD36 with CD117, CD71, and CD105. This combination allowed for the separation of erythroid progenitor cells into four discrete populations along a continuum of progressive maturation, with increasing cell size and decreasing nuclear/cytoplasmic ratio, proliferative capacity and stem cell factor responsiveness. This strategy was validated in uncultured, primary erythroid cells isolated from bone marrow of healthy individuals. Functional colony assays of these progenitor populations revealed enrichment of BFU‐E only in the earliest population, transitioning to cells yielding BFU‐E and CFU‐E, then CFU‐E only. Utilizing CD34/CD105 and GPA/CD105 profiles, all four progenitor stages and all five stages of terminal erythroid differentiation could be identified. Applying this immunophenotyping strategy to primary bone marrow cells from patients with myelodysplastic syndrome, identified defects in erythroid progenitors and in terminal erythroid differentiation. This novel immunophenotyping technique will be a valuable tool for studies of normal and perturbed human erythropoiesis. It will allow for the discovery of stage‐specific molecular and functional insights into normal erythropoiesis as well as for identification and characterization of stage‐specific defects in inherited and acquired disorders of erythropoiesis.
Recent Advances in Visible‐Light‐Driven Photocatalyzed γ‐Cyanoalkylation Reactions
Authors: Guin Soumitra , Majee Debashis , Samanta Sampak 
Published: May 2021

AbstractVisible‐light‐induced photoredox‐catalyzed organic transformations through single‐electron‐transfer pathways have recently come to the limelight in modern organic chemistry. These innovative radical processes appear as ideal tactics for making a diverse set of pharmacologically and synthetically useful organic molecules under sustainable conditions. In this review, we summarize a brief overview of recent status of radical C(sp3)−X (X=C, S, Se, B, F, Cl etc) cross‐coupling reactions of cyclobutanone oxime esters as the surrogates of γ‐cyanoalkyl radicals with various kinds of radical acceptors using photocatalysts irradiated by visible light or natural sunlight. The efficiency of various metal‐salts (Ir, Ru, Cu, Pd etc) and metal‐free organic molecules (eosin Y, rose Bengal, 4CzIPN, HE, PhPTZ, Mes−Acr+ etc) as photocatalysts were thoroughly examined for the above conversions. Furthermore, the mechanism of the said reactions has also been presented. Notably, the described photocatalytic cycles would further bestow a new mechanistic concept for aiming a variety of cyanoalkylated scaffolds.
Base Promoted Intramolecular O‐arylation For The Synthesis of Dibenzo[b,f]oxepinones Toward Dihydroartocarpol D
Authors: Li Kaili , Zhang Kun , Huang He , Zhang Qianqian , Song Chuanjun , Chang Junbiao 
Published: May 2021

AbstractAn efficient base‐promoted intramolecular O‐arylation approach of 2‐halobenzyl 2‐hydroxyphenyl ketones toward the synthesis of dibenzo[b,f]oxepinones has been developed. The products are obtained in good to excellent isolated yields. Further extension of the strategy to the total synthesis of dihydroartocarpol D has been described.
Development of a self‐directed sinonasal surgical anatomy video curriculum: Phase 1 validation
Authors: Bailey C. Eric , Grauer Jordan S. , Chen Philip G. , Rangarajan Sanjeet V. , Chan Yvonne , Tewfik Marc A. , Marino Michael J. , Torabi Mohammad , Le Christopher H. , Chang Eugene H. 
Published: May 2021

BackgroundSinusitis is a common outpatient diagnosis made by physicians and is a reason for referral to otolaryngologists. A foundation in basic sinonasal anatomy is critical in understanding sinus pathophysiology and avoiding complications. Our objective in this study was to develop and to validate a self‐directed surgical anatomy video for medical students.MethodsTwo multimedia videos were developed highlighting sinonasal anatomy. In Video 1 we included audio narration and radiologic imaging. Video 2 incorporated highlighted images from a sinus surgery video. An assessment was developed to test sinonasal anatomy landmarks, spatial recognition of structures, and their clinical relevance. An expert panel of rhinologists scored face and content validity of the curriculum videos and assessment. Factor analysis was used to separate questions into face and content validity domains, and a one‐sample t test was performed.ResultsThe panel scored face validity (Videos 1 and 2: 4.4/5) and content validity (Video 1: 4.5/5, 0.83; Video 2: 4.3/5, 0.75) significantly higher than a neutral response. There were no statistical differences for face or content validity between videos. The assessment was rated suitable (29%) or very suitable (57%) for testing basic sinonasal surgical anatomy, and the majority (71%) of respondents agreed (14%) or strongly agreed (57%) that the assessment thoroughly covered the sinus anatomy content with which medical students should be familiar.ConclusionWe have developed two videos and an assessment that highlight and test sinonasal anatomy. Future studies will aim to identify whether the use of a self‐directed video curriculum improves sinonasal anatomy awareness and whether incorporation of surgical endoscopic videos augments training.
Gut Microbiome Signatures of Risk and Prodromal Markers of Parkinson Disease
Authors: Heinzel Sebastian , Aho Velma T. E. , Suenkel Ulrike , von Thaler Anna‐Katharina , Schulte Claudia , Deuschle Christian , Paulin Lars , Hantunen Sari , Brockmann Kathrin , Eschweiler Gerhard W. , Maetzler Walter , Berg Daniela , Auvinen Petri , Scheperjans Filip 
Published: May 2021

ObjectiveAlterations of the gut microbiome in Parkinson disease (PD) have been repeatedly demonstrated. However, little is known about whether such alterations precede disease onset and how they relate to risk and prodromal markers of PD. We investigated associations of these features with gut microbiome composition.MethodsEstablished risk and prodromal markers of PD as well as factors related to diet/lifestyle, bowel function, and medication were studied in relation to bacterial α‐/β‐diversity, enterotypes, and differential abundance in stool samples of 666 elderly TREND (Tübingen Evaluation of Risk Factors for Early Detection of Neurodegeneration) study participants.ResultsAmong risk and prodromal markers, physical inactivity, occupational solvent exposure, and constipation showed associations with α‐diversity. Physical inactivity, sex, constipation, possible rapid eye movement sleep behavior disorder (RBD), and smoking were associated with β‐diversity. Subthreshold parkinsonism and physical inactivity showed an interaction effect. Among other factors, age and urate‐lowering medication were associated with α‐ and β‐diversity. Constipation was highest in individuals with the Firmicutes‐enriched enterotype, and physical inactivity was most frequent in the Bacteroides‐enriched enterotype. Constipation was lowest and subthreshold parkinsonism least frequent in individuals with the Prevotella‐enriched enterotype. Differentially abundant taxa were linked to constipation, physical inactivity, possible RBD, smoking, and subthreshold parkinsonism. Substantia nigra hyperechogenicity, olfactory loss, depression, orthostatic hypotension, urinary/erectile dysfunction, PD family history, and the prodromal PD probability showed no significant microbiome associations.InterpretationSeveral risk and prodromal markers of PD are associated with gut microbiome composition. However, the impact of the gut microbiome on PD risk and potential microbiome‐dependent subtypes in the prodrome of PD need further investigation based on prospective clinical and (multi)omics data in incident PD cases. ANN NEUROL 2021;90:E1–E12
Chemical Synthesis of Activity‐Based E2‐Ubiquitin Probes for the Structural Analysis of E3 Ligase‐Catalyzed Transthiolation
Authors: Liang Lu‐Jun , Chu Guo‐Chao , Qu Qian , Zuo Chong , Mao Junxiong , Zheng Qingyun , Chen Jingnan , Meng Xianbin , Jing Yangwode , Deng Haiteng , Li Yi‐Ming , Liu Lei 
Published: May 2021

AbstractActivity‐based E2 conjugating enzyme (E2)‐ubiquitin (Ub) probes have recently emerged as effective tools for studying the molecular mechanism of E3 ligase (E3)‐catalyzed ubiquitination. However, the preparation of existing activity‐based E2‐Ub probes depends on recombination technology and bioconjugation chemistry, limiting their structural diversity. Herein we describe an expedient total chemical synthesis of an E2 enzyme variant through a hydrazide‐based native chemical ligation, which enabled the construction of a structurally new activity‐based E2‐Ub probe to covalently capture the catalytic site of Cys‐dependent E3s. Chemical cross‐linking coupled with mass spectrometry (CXMS) demonstrated the utility of this new probe in structural analysis of the intermediates formed during Nedd4 and Parkin‐mediated transthiolation. This study exemplifies the utility of chemical protein synthesis for the development of protein probes for biological studies.
Histological analysis of ankylothecodonty in Silesauridae (Archosauria: Dinosauriformes) and its implications for the evolution of dinosaur tooth attachment
Authors: Mestriner Gabriel , LeBlanc Aaron , Nesbitt Sterling J. , Marsola Júlio C. A. , Irmis Randall B. , Da‐Rosa Átila Augusto Stock , Ribeiro Ana Maria , Ferigolo Jorge , Langer Max 
Published: May 2021

AbstractDinosaurs possess a form of tooth attachment wherein an unmineralized periodontal ligament suspends each tooth within a socket, similar to the condition in mammals and crocodylians. However, little information is known about tooth attachment and implantation in their close relatives, the silesaurids. We conducted a histological survey of several silesaurid taxa to determine the nature of tooth attachment in this phylogenetically and paleoecologically important group of archosaurs. Our histological data demonstrate that these early dinosauriforms do not exhibit the crocodilian/dinosaur condition of a permanent gomphosis, nor the rapid ankylosis that is plesiomorphic for amniotes. Instead, all sampled silesaurids exhibit delayed ankylosis, a condition in which teeth pass through a prolonged stage where the teeth are suspended in sockets by a periodontal ligament, followed by eventual mineralization and fusion of the tooth to the jaws. This suggests that tooth attachment in crocodylians and dinosaurs represent the further retention of an early ontogenetic stage compared to silesaurids, a paedomorphic trend that is mirrored in the evolution of synapsid tooth attachment. It also suggests that the dinosaur and crocodylian gomphosis was convergently acquired via heterochrony or, less likely, that the silesaurid condition represents a reversal to a plesiomorphic state. Moreover, if Silesauridae is nested within Ornithischia, a permanent gomphosis could be convergent between the two main dinosaur lineages, Ornithischia and Saurischia. These results demonstrate that dental characters in early archosaur phylogenies must be chosen and defined carefully, taking into account the relative duration of the different phases of dental ontogeny.