bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complexes of Borane and 1,3,5‐Triazinane‐Derived Carbenes
Authors: Smirnov Vladimir O. , Levin Vitalij V. , Dilman Alexander D. 
Published: April 2024

AbstractComplexes of borane with six‐membered N‐heterocyclic carbenes derived from readily accessible 1,3,5‐triazinium salts are described. Similar to the widely used imidazolium‐type borane complex, the obtained complexes behave as agents for the hydrogen atom transfer in the Giese reaction and as sources of the boryl radicals in addition to imines. The amine nitrogen of these complexes does not undergo alkylation, but it can bind with another borane molecule.
Palladium‐Catalyzed Atroposelective Suzuki–Miyaura Coupling to Construct Axially Chiral Tetra‐Substituted α‐Boryl Styrenes
Authors: Li Xiaorui , Kong Lingyu , Yin Shuxin , Zhou Hengrui , Lin Aijun , Yao Hequan , Gao Shang 
Published: April 2024

AbstractPalladium‐catalyzed Suzuki–Miyaura (SM) coupling is a valuable method for forming C─C bonds, including those between aryl moieties. However, achieving atroposelective synthesis of axially chiral styrenes via SM coupling remains challenging. In this study, a palladium‐catalyzed atroposelective Suzuki–Miyaura coupling between gem‐diborylalkenes and aryl halides is presented. Using the monophosphine ligand Me‐BI‐DIME (L2), a range of axially chiral tetra‐substituted acyclic styrenes with high yields and excellent enantioselectivities are successfully synthesized. Control experiments reveal that the gem‐diboryl group significantly influences the product enantioselectivities and the coupling prefers to occur at sites with lower steric hindrance. Additionally, the alkenyl boronate group in the products proves versatile, allowing for various transformations while maintaining high optical purities.
Teff grass increases summer forage availability in the Rolling Plains of Texas
Authors: Kimura Emi , Ramirez Jonathan 
Published: April 2024

AbstractTeff [Eragrostis tef (Zucc.) Trotter] grass has gained popularity in the United States as an emergency summer forage for livestock due to its drought tolerance and rapid growth habit. An alternative forage would benefit Texas Rolling Plains growers due to the summer forage shortage caused by drought conditions. However, among the teff research conducted in the United States, there is great variability in the forage yields and nutritive values depending on the amount of nitrogen and available water. The objective of the study was to evaluate forage productivity and nutritive value of teff in the Texas Rolling Plains under irrigated and dryland conditions with two nitrogen rates and application timings. Nitrogen fertilizer treatments included single applications of either 50 or 100 lb a−1 applied at planting and a split application of either 50 or 100 lb a−1 applied both at planting and after the first harvest. No differences were observed among nitrogen rates and application methods in the irrigated trial (5286 lb a−1). The split application of 100 lb a−1 produced the greatest total yield in the dryland trial (3096 lb a−1) with no yield advantage of 100 lb N a−1 over 50 lb N a−1 at the first cutting. Forage nutritive values were similar to the warm‐season forage species utilized in the region. This study showed that teff can be an alternative forage species in the region. Future research will include planting dates, nitrogen application timing, cutting height, and the interaction of these factors on yield and nutritive values of teff.
An investigation of the price discovery role of futures markets: A dynamic time warping analysis of the United States corn markets
Authors: Miljkovic Dragan , Vatsa Puneet , Olson Frayne 
Published: April 2024

AbstractFutures markets are critical to price discovery and often dominate spot markets. We analyze the linkages between daily corn futures and spot prices in the United States using dynamic time warping. This nonparametric pattern recognition technique has several advantages over traditional time series methods. First, it can detect multiple changes in the lead‐lag associations between the two prices within short intervals; the duration with which one series leads or lags another is not assumed to be fixed. Second, the method can be applied to time series without regard to their stationarity properties. This greatly expands the scope of this method to accommodate a wide range of time series. Third, it lends itself well to studying small samples, which econometricians encounter routinely. Fourth, the results are presented intelligibly using intuitive visualizations. Our results show that futures markets are critical to price discovery; nevertheless, spot markets dominate futures markets intermittently. We discuss the results in detail, setting them in the proper context. [EconLit Citations: C14, C32, Q02, Q11].
Together but not scrambled: A perspective on chaotic printing/bioprinting
Authors: Trujillo‐de Santiago Grissel , Alvarez Mario Moisés 
Published: April 2024

AbstractStructures in nature are often multi‐material, and their structures have a fine balance between segregation and aggregation (mixed, but not scrambled) that provides functionality. Chaotic fabrication, a technology that exploits the ability of chaotic advection to create predictable and reproducible multilayered structures, excels at producing materials where this balance can be achieved and finely tuned. This method is based on the use of chaotic mixing systems, which can produce constructs with highly organized internal micro‐architecture in a simple and cost‐effective way. This manuscript provides a perspective on how chaotic printing can be a great enabler in the manufacture of advanced materials, including living tissues. Chaotic printing may overcome many of the critical hurdles that are currently faced in manufacturing and biofabrication (e.g., creating a wide array of interfaces, reaching high resolutions rapidly and at low cost, and producing densely vascularized tissues). The manuscript introduces the technology, explains how the idea originated, presents a timeline that provides a recapitulation of the milestones achieved so far, describes the main characteristics, advantages, limitations, and challenges of the technology, and concludes with future perspectives on the evolution and use of this versatile method.
In situ/Operando Synchrotron Radiation Analytical Techniques for CO2/CO Reduction Reaction: From Atomic Scales to Mesoscales
Authors: Xu Yi Ning , Mei Bingbao , Xu Qiucheng , Fu Huai Qin , Zhang Xin Yu , Liu Peng Fei , Jiang Zheng , Yang Hua Gui 
Published: April 2024

AbstractElectrocatalytic carbon dioxide/carbon monoxide reduction reaction (CO(2)RR) has emerged as a prospective and appealing strategy to realize carbon neutrality for manufacturing sustainable chemical products. Developing highly active electrocatalysts and stable devices has been demonstrated as effective approach to enhance the conversion efficiency of CO(2)RR. In order to rationally design electrocatalysts and devices, a comprehensive understanding of the intrinsic structure evolution within catalysts and micro‐environment change around electrode interface, particularly under operation conditions, is indispensable. Synchrotron radiation has been recognized as a versatile characterization platform, garnering widespread attention owing to its high brightness, elevated flux, excellent directivity, strong polarization and exceptional stability. This review systematically introduces the applications of synchrotron radiation technologies classified by radiation sources with varying wavelengths in CO(2)RR. By virtue of in situ/operando synchrotron radiationanalytical techniques, we also summarize relevant dynamic evolution processes from electronic structure, atomic configuration, molecular adsorption, crystal lattice and devices, spanning scales from the angstrom to the micrometer. The merits and limitations of diverse synchrotron characterization techniques are summarized, and their applicable scenarios in CO(2)RR are further presented. On the basis of the state‐of‐the‐art fourth‐generation synchrotron facilities, a perspective for further deeper understanding of the CO(2)RR process using synchrotron radiation analytical techniques is proposed.
A novel hybrid forecasting approach for NOx emission of coal‐fired boiler combined with CEEMDAN and self‐attention improved by LSTM
Authors: Yan Hua , Chen Yunchi , Yang Bin , Yang Yang , Ni Hu , Wang Ying 
Published: April 2024

AbstractThe precise prediction of NOx generation concentration in coal‐fired boilers serves as the foundational cornerstone for the judicious optimization and control of selective catalytic reduction denitrification (SCR) systems. Owing to the intricate nature of the denitrification process within SCR, there exists a temporal delay in regulating the ammonia injection rate based on the monitored data of NOx concentration at the SCR inlet. Such delays can give rise to ammonia leakage and subsequent obstruction of the air preheater. In light of this, a predictive model, CEEMDAN‐LSTM‐SA, is proposed as an amalgamation of data decomposition and the LSTM (long short‐term memory) fusion self‐attention mechanism within a deep learning network, which is introduced to forecast the NOx emission concentration at the SCR inlet of coal‐fired units. To mitigate the impact of data outliers on the training effectiveness of the model, a clustering method coupled with a statistical testing strategy is initially applied to refine the dataset first. CEEMDAN data decomposition technology is leveraged to facilitate the breakdown of data, alleviating its non‐stationary and intricate characteristics. Subsequently, through spectral analysis, the decomposed components are grouped and aggregated to form novel data elements, which are then subjected to prediction by the constructed LSTM‐SA deep learning network. The ultimate NOx emission concentration prediction value is derived through a process of fusion. Upon scrutinizing and comparing the predictions derived from various models using coal‐fired power plant data, it is evident that the performance metrics of CEEMDAN‐LSTM‐SA predictions exhibit a mean absolute error of 7.425, mean absolute percentage error of 2.415%, root mean square error of 9.715, R‐squared (R2) value of .789, mean absolute relative error of 2.109%, and a Theil's information criterion of .016. In contrast to other models, including traditional self‐attention networks, LSTM, and LSTM‐SA combination networks, CEEMDAN‐LSTM‐SA proposed in this study demonstrates superior prediction accuracy and enhanced generalization capabilities. Consequently, this predictive model stands poised to furnish an efficacious framework for the SCR ammonia injection strategy within thermal power units.
Curating the Chinese ancient book catalogs: Leveraging the dual roles of humanities scholars as experts and users in collaborative practice
Authors: Li Wenqi , Wang Jun , Wang Fengxiang 
Published: April 2024

AbstractChinese ancient book catalogs are important cultural heritage and academic resources for the study of ancient Chinese history and culture. These catalogs need to be curated so that their value can be fully exploited in today's digital environment. This study is based on a collaborative curation project where eight representative ancient catalogs were curated into a diachronic dataset and tools to discover and analyze the data were developed. We reviewed literature and consulted humanities scholars to derive the characteristics and curation requirements of the ancient catalogs. A collaborative model was proposed based on the requirements to guide the curation process. This model reveals the duality of humanities scholars' role in collaborative curation and depicts main curation activities including metadata and description, appraisal and selection, data processing, developing tools, access and use, and evolution. Lessons learned from the curation practice include two main issues—project personnel and humanities scholars' acceptance of visualization. The study also yields a dataset and a set of tools that can be directly used by scholars interested in knowledge organization and ancient catalog related topics.
New Pyridine Dicarbene Pincer Ligands with Ring Expanded NHCs and their Nickel and Chromium Complexes
Authors: Papangelis Evangelos , Pelzer Katrin , Gourlaouen Christophe , Armspach Dominique , Braunstein Pierre , Danopoulos Andreas A. , Bailly Corinne , Tsoureas Nikolaos , Gerokonstantis Dimitrios Triantafyllos 
Published: April 2024

AbstractThe pincer complexes [NiIIBr(CNC)]Br (4), [CrIIIBr3(CNC)] (5 a) and [CrIIIBr2.3Cl0.7(CNC)] (5 b), where CNC=3,3′‐(pyridine‐2,6‐diyl)bis(1‐mesityl‐3,4,5,6‐tetrahydropyrimidin‐2‐ylidene), were obtained from the novel ligand CNC, generated in situ from the precursor (CHNCH)Br2 and [NiIIBr2(PPh3)2] or from [CrII{N(SiMe3)2}2(THF)2] and (CHNCH)Br2 by aminolysis, respectively. The tetrahedrally distorted square planar (τ4≅0.30) geometry and the singlet ground state of Ni in 4 were attributed to steric constraints of the CNC backbone. Computational methods highlighted the dependence of the coordination geometry and the singlet‐triplet energy difference on the size of the N‐substituent of the tetrahydropyrimidine wingtips and contrasted it to the situation in 5‐membered imidazolin‐2‐ylidene pincer analogues. The octahedral CrIII metal center in 5 a and 5 b is presumably formed after one electron oxidation from CH2Cl2. 4/MAO and 5 a/MAO were catalysts of moderate activity for the oligomerization and polymerization of ethylene, respectively. The analogous (CH^N^CH)Br2 precursor, where (CH^N^CH)=3,3′‐(pyridine‐2,6‐diylbis(methylene))bis(1‐mesityl‐3,4,5,6‐tetrahydropyrimidin‐1‐ium), was also prepared, however its coordination chemistry was not studied due to the inherent instability of the resulting free C^N^C ligand.
Tuning Green Explosives through SNAr Chemistry
Authors: Nikitin Sergei , Diness Frederik 
Published: April 2024

AbstractReactivity and regioselectivity of SNAr‐type fluorine substitution with azide in polyfluorosubstituted nitrobenzenes was studied both theoretically and experimentally. The obtained polyazido‐substituted nitrobenzene derivatives were extensively characterized by NMR, IR, HPLC, X‐ray, and DFT methods. It was found that the substitution with the azide nucleophile occurs first at the para‐ and the ortho‐positions to the NO2‐group and that transazidation reactions also occur here. Thermal decomposition of prepared azidonitrobenzenes was studied both in controlled (kinetic decay) and uncontrolled (explosion) modes. In case of the controlled thermal decomposition of ortho‐azidonitrobenzenes, benzofuroxans were found as major products of the reaction unless another azido group was adjacent to the furoxan moiety. The bursting power of azidonitrobenzenes was found to rise gradually with the number of the azide substituents in the aromatic ring.
A fast and efficient liquid chromatography–tandem mass spectrometry method for measuring l‐ and d‐amino acids in the urine of patients with immunoglobulin A nephropathy
Authors: Zha Zhijian , Wang Ruihua , Wang Qian , Chen Fahui , Ye Ziyang , Li Yafeng 
Published: April 2024

AbstractImmunoglobulin nephropathy (IgAN) stands as the most prevalent primary glomerular nephropathy globally, typically diagnosed through an invasive renal biopsy. Emerging research suggests the significant involvement of chiral amino acids in kidney disease progression. This study introduces a nonderivative LC–tandem mass spectrometry approach, offering efficient separation outcomes within 15 min for identifying chiral amino acids in human urine samples. Subsequently, using this method, the analysis of l‐ and d‐amino acids in the urine of both patients with IgAN and healthy individuals was conducted. Fourteen d‐amino acids and 20 l‐amino acids were identified in the urine samples obtained from 17 patients with IgAN and 21 healthy individuals. The results indicated notable variances in the concentrations of both l‐ and d‐amino acids between the IgAN and healthy control groups. In contrast to the healthy group, the IgAN group exhibited higher mean urine concentrations of most l‐amino acids and lower concentrations of d‐amino acids. Furthermore, correlations between amino acids and clinical markers were investigated. These results propose a novel method for monitoring trace amino acids in urine samples and introduce a new concept for potential markers of IgAN.
Developing tomorrow's leaders: Self‐esteem and teamwork go hand in hand
Authors: May Rachel 
Published: April 2024

A new study published in a special issue of Education Sciences by Elena De Prada, Mercedes Mareque, and Margarita Pino‐Juste finds that there is a “relationship between teamwork skills and the successful development of self‐esteem.” Researchers determined that leadership skills aren’t necessarily innate and can be taught, especially when group work is closely managed. The study's subjects were social science students.
Diaporchalasins A–E, New Cytochalasins from the Endophytic Fungus Diaporthe sp. BMX12 Isolated from Aquilaria sinensis
Authors: Yang Li , Wang Qi , Ma Qing‐Yun , Xie Qing‐Yi , Gai Cui‐Juan , Wu You‐Gen , Dai Hao‐Fu , Zhao You‐Xing 
Published: April 2024

AbstractFive new cytochalasins, diaporchalasins A–E (1–5), together with 14 known congeners (6–19) were isolated from the endophytic fungus Diaporthe sp. BMX12, which was isolated from the branches of Aquilaria sinensis. The structures of the new compounds were elucidated by extensive spectroscopic analyses including high‐resolution electron spray ionization mass spectrometry (HR‐ESI‐MS) and nuclear magnetic resonance (NMR). Their absolute configurations were assigned by theoretical electronic circular dichroism (ECD) calculations. Compounds 11 and 12 featuring a keto carbonyl at C‐21 displayed cytotoxicity toward K562, BEL‐7402, SGC‐7901, A549, and HeLa cell lines with IC50 values ranging from 4.4 to 47.4 μM.
Why Does Monoamine Oxidase (MAO) Catalyze the Oxidation of Some Tetrahydropyridines?
Authors: Price Nathan J. , Nakamura Akiko , Castagnoli Neal , Tanko James M. 
Published: April 2024

AbstractResults pertaining to the mechanism of the oxidation of the tertiary amine 1‐methyl‐4‐(1‐methyl‐1‐H‐pyrrol‐2‐yl)‐1,2,3,6‐tetrahydropyridine (MMTP, a close analog of the Parkinsonism inducing compound MPTP) by 3‐methyllumiflavin (3MLF), a chemical model for the FAD cofactor of monoamine oxidase, are reported. MMTP and related compounds are among the few tertiary amines that are monoamine oxidase B (MAO−B) substrates. The MMTP/3MLF reaction is catalytic in the presence of O2 and the results under anaerobic conditions strongly suggest the involvement of radical intermediates, consistent with a single electron transfer mechanism. These observations support a new hypothesis to explain the MAO‐catalyzed oxidations of amines. In general, electron transfer is thermodynamically unfavorable, and as a result, most 1° and 2° amines react via one of the currently accepted polar pathways. Steric constraints prevent 3° amines from reacting via a polar pathway. Those select 3° amines that are MAO substrates possess certain structural features (e. g., a C−H bond that is α‐ both to nitrogen and a C=C) that dramatically lower the pKa of the corresponding radical cation. Consequently, the thermodynamically unfavorable electron transfer equilibrium is driven towards products by an extremely favorable deprotonation step in the context of Le Chatelier's principle.
Systematic Analysis of the Effect of Genomic Knock‐Out of Non‐Essential Promiscuous HAD‐Like Phosphatases YcsE, YitU and YwtE on Flavin and Adenylate Content in Bacillus Subtilis
Authors: Scharf Alexandra , La‐Rostami Farshad , Illarionov Boris A. , Nemes Vivien , Feldmann Anna M. , Höft Lars S. , Lösel Henri , Bacher Adelbert , Fischer Markus 
Published: April 2024

AbstractStudying the metabolic role of non‐essential promiscuous enzymes is a challenging task, as genetic manipulations usually do not reveal at which point(s) of the metabolic network the enzymatic activity of such protein is beneficial for the organism. Each of the HAD‐like phosphatases YcsE, YitU and YwtE of Bacillus subtilis catalyzes the dephosphorylation of 5‐amino‐6‐ribitylamino‐uracil 5′‐phosphate, which is essential in the biosynthesis of riboflavin. Using CRISPR technology, we have found that the deletion of these genes, individually or in all possible combinations failed to cause riboflavin auxotrophy and did not result in significant growth changes. Analysis of flavin and adenylate content in B. subtilis knockout mutants showed that (i) there must be one or several still unidentified phosphatases that can replace the deleted proteins; (ii) such replacements, however, cannot fully restore the intracellular content of any of three flavins studied (riboflavin, FMN, FAD); (iii) whereas bacterial fitness was not significantly compromised by mutations, the intracellular balance of flavins and adenylates did show some significant changes.
An Immersion Ultrasonic Testing‐Based Research Platform for Studying Electroplating Kinetics
Authors: Zirui Yang , Yunda Chen , Zou Fangxin , Cegla Frederic B. 
Published: April 2024

AbstractElectroplating is widely exploited in numerous application areas. Understanding the kinetics of electroplating, which is essentially a dynamic phenomenon, is crucial to making use of it appropriately in the real world. Currently, there exist a variety of research tools for studying electroplating kinetics, each with its own pros and cons. In this paper, we introduce a novel, immersion ultrasonic testing‐based technique that carries out in situ, direct monitoring of the thickness increase of an electroplated layer. Through careful design and optimization of the measurement setup and the signal processing protocol, the measurement resolution of the technique was able to reach a sub‐micron level. Via a number of demonstrative zinc plating experiments that were performed under different conditions, the measurement accuracy of the technique was thoroughly validated by a number of independent methods. All in all, the technique can become a promising alternative tool for studying the kinetics of different electroplating processes, supplementing the existing toolbox with the capability of providing a new class of information.
Theoretical Study of the Ternary Compound Monolayer CuP2Se for Photocatalytic Water Splitting with Efficient Optical Absorption
Authors: Qiu Xiaole , Wang Xiaoxuan , Liu Xiaolu , Yuan Saifei , Han Kai , Yang Hongchao 
Published: April 2024

AbstractUtilizing photocatalytic method to produce hydrogen by splitting water is an efficient strategy to solve the hotspot issues of energy crisis and environmental pollution. Herein, we systematically investigate the corresponding properties of the reported Cu‐bearing ternary compound monolayer CuP2Se by using the first‐principle calculations. The monolayer CuP2Se has quite small cleavage energy of 0.51 J/m2, indicating it can be easily produced by the mechanical exfoliation method experimentally. In addition, it is an indirect bandgap semiconductor material which has a moderate value of 1.91 eV. The conduction band minimum (CBM) and valence band maximum (VBM) can perfectly straddle the redox potentials of water when a biaxial strain of −4% to 4% is applied, unveiling the high photocatalytic thermodynamic stability of monolayer CuP2Se in response to the effect of solvent tension. Remarkably, the monolayer CuP2Se also demonstrates significant sunlight capturing ability in the visible region. The outstanding electronic and optical properties suggest that the monolayer CuP2Se is undoubtedly a viable material for photocatalytic water splitting.