bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cover crop and minimum tillage effects on yield, irrigation water use, and net returns
Authors: Badon Thomas B. , Prince Czarnecki Joby M. , Krutz L. Jason , Shockley Jordan M. , Baker Beth H. 
Published: April 2021

AbstractThe addition of cover crops and minimum tillage to current row‐crop production practices in the mid‐southern United States could holistically improve the sustainability of these farming systems. This relatively short‐term study was conducted to determine if the addition of these practices into corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotational systems in the region would decrease irrigation water use while improving yield, irrigation water use efficiency, and net returns above production costs. The effects of cover crops and minimum tillage on these parameters were investigated from 2017 to 2019 on six pairs of production fields in northwest Mississippi. A pair was created by dividing a single field that had been under uniform management into two fields that were land leveled and hydrologically separated with an earthen berm. Control fields were managed according to standard practices within the region, which include winter fallow and multiple tillage passes, whereas treatment fields were managed with winter cover crops and minimum tillage. The addition of cover crops and minimum tillage had no effect on yield (p = .09), irrigation water use efficiency (p = .38), or irrigation water applied (p = .83). The net economic return on average across all site years was a loss of US$233 ha–1. These results reflect the short study period as changes resulting from these practices often occur on a greater time scale. The value proposition for adoption of a cover crop–minimum tillage system will be challenging in the mid‐southern United States if potential benefits are to be expected in the early years of adoption.
Theoretical impact of the AT(N) framework on dementia using a community autopsy sample
Authors: Burke Bridget Teevan , Latimer Caitlin , Keene C. Dirk , Sonnen Joshua A. , McCormick Wayne , Bowen James D. , McCurry Susan M. , Larson Eric B. , Crane Paul K. 
Published: April 2021

AbstractThe AT(N) research framework categorizes eight biomarker profiles using amyloid (A), tauopathy (T), and neurodegeneration (N), regardless of dementia status. We evaluated associations with dementia risk in a community‐based cohort by approximating AT(N) profiles using autopsy‐based neuropathology correlates, and considered cost implications for clinical trials for secondary prevention of dementia based on AT(N) profiles. We used Consortium to Establish a Registry for Alzheimer's Disease (moderate/frequent) to approximate A+, Braak stage (IV‐VI) for T+, and temporal pole lateral ventricular dilation for (N)+. Outcomes included dementia prevalence at death and incidence in the last 5 years of life. A+T+(N)+ was the most common profile (31%). Dementia prevalence ranged from 14% (A–T–[N]–) to 79% (A+T+[N]+). Between 8% (A+T–[N]–) and 68% (A+T+[N]–) of decedents developed incident dementia in the last 5 years of life. Clinical trials would incur substantial expense to characterize AT(N). Many people with biomarker‐defined preclinical Alzheimer's disease will never develop clinical dementia during life, highlighting resilience to clinical expression of AD neuropathologic changes and the need for improved tools for prediction beyond current AT(N) biomarkers.
Selectivity and Targeting of G‐Quadruplex Binders Activated by Adaptive Binding and Controlled by Chemical Kinetics
Authors: Zhu Bo‐Chen , He Juan , Liu Wenting , Xia Xiao‐Yu , Liu Liu‐Yi , Liang Bing‐Bing , Yao Hua‐Gang , Liu Bing , Ji Liang‐Nian , Mao Zong‐Wan 
Published: April 2021

AbstractG‐quadruplexes (G4s) are prevalent in oncogenes and are potential antitumor drug targets. However, binding selectivity of compounds to G4s still faces challenges. Herein, we report a platinum(II) complex (Pt1), whose affinity to G4‐DNA is activated by adaptive binding and selectivity controlled by binding kinetics. The resolved structure of Pt1/VEGF‐G4 (a promoter G4) shows that Pt1 matches 3′‐G‐tetrad of VEGF‐G4 through Cl−‐dissociation and loop rearrangement of VEGF‐G4. Binding rate constants are determined by coordination bond breakage/formation, correlating fully with affinities. The selective rate‐determining binding step, Cl−‐dissociation upon G4‐binding, is 2–3 orders of magnitude higher than dsDNA. Pt1 potently targets G4 in living cells, effectively represses VEGF expression, and inhibits vascular growth in zebrafish. We show adaptive G4‐binding activation and controlled by kinetics, providing a complementary design principle for compounds targeting G4 or similar biomolecules.
Ambiphilic Al−Cu Bonding
Authors: Liu Han‐Ying , Schwamm Ryan J. , Hill Michael S. , Mahon Mary F. , McMullin Claire L. , Rajabi Nasir A. 
Published: April 2021

AbstractCopper‐alumanyl complexes, [LCu‐Al(SiNDipp)], where L=carbene=NHCiPr(N,N′‐diisopropyl‐4,5‐dimethyl‐2‐ylidene) andMe2CAAC (1‐(2,6‐diisopropylphenyl)‐3,3,5,5‐tetramethyl‐pyrrolidin‐2‐ylidene) and featuring unsupported Al−Cu bonds, have been prepared. Divergent reactivity observed with carbodiimides and CO2implies an ambiphilicity in the Cu–Al interaction that is dependent on the identity of the carbene co‐ligand.
Cyclic Diaryl λ3‐Bromanes as Original Aryne Precursors
Authors: Lanzi Matteo , Dherbassy Quentin , Wencel‐Delord Joanna 
Published: April 2021

AbstractDespite the widespread application of hypervalent iodines, the corresponding λ3‐bromanes are less explored. Herein we report a general, safe, and high‐yielding strategy to access cyclic diaryl λ3‐bromanes. These unique compounds feature reactivity that is appealing and complementary to that of λ3‐iodanes, generating arynes under mild reaction conditions and in the presence of a weak base. Accordingly, formal meta‐selective transition‐metal‐free C–O and C–N couplings may be achieved. Mechanistic studies unambiguously support the aryne generation mechanism.
Synthesis of new 1,2,4‐triazole–(thio)semicarbazide hybrid molecules: Their tyrosinase inhibitor activities and molecular docking analysis
Authors: Gultekin Ergün , Bekircan Olcay , Kolcuoğlu Yakup , Akdemir Atilla 
Published: April 2021

AbstractTyrosinase inhibition is very important in controlling melanin synthesis. If melanin synthesis is not controlled in metabolism, an unwanted increase in melanin synthesis occurs. As melanin plays a role in the formation of skin color, its unusual levels cause some skin disorders such as pregnancy scars, age spots, and especially skin cancer (melanoma). However, the tyrosinase activity is also related to Parkinson's disease and some neurodegenerative diseases. For all these reasons, the medicinal as well as the cosmetic industries focus on research on tyrosinase inhibitors for the treatment of skin disorders and some neurodegenerative diseases. In this study, 32 new 1,2,4‐triazole–(thio)semicarbazide hybrid molecules (6a–p and 7a–p) were synthesized, starting from 4‐amino‐1‐pentyl‐3‐phenyl‐1H‐1,2,4‐triazole‐5(4H)‐one. These compounds were evaluated for their inhibitory activity against mushroom tyrosinase. The results indicated that 6h, 6m, 6n, and 6p exhibited the most effective inhibitory activity, with IC50 values of 0.00162 ± 0.0109, 0.00166 ± 0.0217, 0.00165 ± 0.019, and 0.00197 ± 0.0063 μM, respectively, compared with kojic acid as the reference drug (IC50 = 14.09 ± 0.02 μM). Also, molecular docking analyses were performed to suggest possible binding poses for the ligands. As a result, derivatives 6h, 6m, 6n, and 6p can be used as promising tyrosinase inhibitor candidates in the medicinal, cosmetics, or food industries.
Structural controllability of networked systems with general heterogeneous subsystems
Authors: Mu Jianbin , Wu Jing , Li Ning , Zhang Xiaohu , Li Shaoyuan 
Published: April 2021

AbstractIn this note, we investigate structural controllability of networked systems in which subsystems have high‐order and heterogeneous dynamics and are coupled through relative state variables. It is aimed to search conditions for subsystem dynamics, under which structural controllability of the whole network essentially depends only on network topology as well as subsystem interconnection links. Necessary and/or sufficient conditions for structural controllability are given by simplifying subsystem dynamics. As an application, these criteria are utilized to design network topology that minimizes the number of subsystem interconnection links under the requirement of structural controllability without concerning subsystem dynamics, which is also much more efficient computationally than a direct design for the global system. The effectiveness of the criteria is demonstrated through several examples.
Brettschichtholz aus Buche
Authors: Ehrhart Thomas , Steiger René , Frangi Andrea 
Published: April 2021

AbstractDas Holz der Rotbuche (Fagus sylvatica L.) wird gegenwärtig nur in sehr geringem Maße für die Produktion von Brettschichtholz (BSH) verwendet. Obwohl diese in Mitteleuropa am weitesten verbreitete Laubholzart ein sehr hohes Potenzial hinsichtlich Festigkeit und Steifigkeit besitzt, wurde sie, neben dem Einsatz im Bahnbau (Schwellen), bisher überwiegend in der Möbelindustrie eingesetzt oder wird – mit geringer Wertschöpfung verbunden – häufig thermisch verwertet. Ein Hauptgrund dafür sind fehlende Normen und Richtlinien, welche die Herstellung und die mechanischen Eigenschaften von BSH aus Buche regulieren würden. In diesem Beitrag wird eine umfangreiche Forschungsarbeit zur Bestimmung der mechanischen Eigenschaften von BSH aus Buche vorgestellt. Es wurden Biege‐, Zug‐, Druck‐, Knick‐ und Schubversuche an Buchen‐BSH‐Bauteilen unterschiedlicher Querschnitte und Festigkeitsklassen durchgeführt, welche durch numerische Modellierungen ergänzt wurden. Die daraus abgeleiteten mechanischen Eigenschaften von Buchen‐BSH, Formeln zur Berücksichtigung von Größeneffekten bei Biege‐ und Schubbeanspruchung sowie Knickkurven für die Berechnung stabilitätsgefährdeter Stützen aus Buchen‐BSH werden in diesem Bericht präsentiert.
Benzimidazole‐based turn‐on fluorescence probe developed for highly specific and ultrasensitive detection of hypochlorite ions in living cells
Authors: Yang Yi , Cheng Siyao , Dong Wei 
Published: April 2021

AbstractHypochlorite (ClO−), as one of the active oxygen species (ROS), plays an essential role in the cellular defence system and organism immunity. In this paper, we successfully synthesized a new ‘turn‐on’ fluorescent probe BMF based on benzimidazole and characterized it by spectroscopic methods. The designed probe can quickly respond to ClO− with the obvious colour change from pink to colourless. Notably, the probe BMF exhibited almost no fluorescence, but showed strong fluorescence after adding ClO−, including an excellent fluorescence turn‐on effect. The fluorescence turn‐on phenomenon of BMF was attributed to the strong oxidation of ClO−, which severed the connecting double bond and disrupted the intramolecular charge transfer (ICT) system, plus light‐induced electron transfer effect between the fluorophore and the recognition group was discontinued. In addition, the cytotoxicity assay showed that the probe had lower cytotoxicity. Based on these advantages, we demonstrated that probe BMF might be a good candidate for detecting ClO− in biological systems.
Dianthracenylazatrioxa[8]circulene: Synthesis, Characterization and Application in OLEDs
Authors: Pedersen Stephan K. , Pedersen Viktor B. R. , Kamounah Fadhil S. , Broløs Line M. , Baryshnikov Glib V. , Valiev Rashid R. , Ivaniuk Khrystyna , Stakhira Pavlo , Minaev Boris , Karaush‐Karmazin Nataliya , Ågren Hans , Pittelkow Michael 
Published: April 2021

AbstractA soluble, green‐blue fluorescent, π‐extended azatrioxa[8]circulene was synthesized by oxidative condensation of a 3,6‐dihydroxycarbazole and 1,4‐anthraquinone by using benzofuran scaffolding. This is the first circulene to incorporate anthracene within its carbon framework. Solvent‐dependent fluorescence and bright green electroluminescence accompanied by excimer emission are the key optical properties of this material. The presence of sliding π‐stacked columns in the single crystal of dianthracenylazatrioxa[8]circulene is found to cause a very high electron‐hopping rate, thus making this material a promising n‐type organic semiconductor with an electron mobility predicted to be around 2.26 cm2 V−1 s−1. The best organic light‐emitting diode (OLED) device based on the dianthracenylazatrioxa[8]circulene fluorescent emitter has a brightness of around 16 000 Cd m−2 and an external quantum efficiency of 3.3 %. Quantum dot‐based OLEDs were fabricated by using dianthracenylazatrioxa[8]circulene as a host matrix material.
STED Imaging the Dynamics of Lysosomes by Dually Fluorogenic Si‐Rhodamine
Authors: Fan Mengting , An Haiyan , Wang Chuanfeng , Huo Shuhui , Wang Ting , Cui Xiaoyan , Zhang Dazhi 
Published: April 2021

AbstractSuper‐resolution microscopy (SRM) imaging of the finite subcellular structures and subtle bioactivities inside organelles delivers abundant cellular information with high fidelity to unravel the intricate biological processes. An ideal fluorescent probe with precise control of fluorescence is critical in SRM technique like stimulated emission depletion (STED). Si‐rhodamine was decorated with both targeting group and H+‐receptor, affording the dually fluorogenic Si‐rhodamine in which the NIR fluorescence was efficiently controlled by the coalescent of spirolactone‐zwitterion equilibrium and PeT mechanism. The dually fluorogenic characters of the probe offer a perfect mutual enhancement in sensitivity, specificity and spatial resolution. Strong fluorescence only released in the existence of targeting protein at acidic lysosomal pH, ensured precisely tracking the dynamic of lysosomal structure and pH in living cells by STED.
N‐Enriched Porous Carbon/SiO2 Composites Derived from Biomass Rice Husks for Boosting Li‐Ion Storage: Insight into the Effect of N‐Doping
Authors: Feng Yi , Liu Li , Liu Xiaoyang , Li Yixin , Wu Yunpeng , Zhu Yanchao , Wang Xiaofeng 
Published: April 2021

AbstractA N‐enriched porous carbon/SiO2 (SiO2/NC) composite from rice husks was prepared by ball milling and tested as a stable anode for lithium ion batteries (LIBs), in which the homogeneous dispersion of SiO2 nanoparticles and carbon matrix, and high level of N‐doping can be realized simultaneously. The influence of N‐doping on a series of SiO2/NCs was systematically studied; this proved that the porosity, N‐doping content, and electronic conductivity of SiO2/NC can be controlled by adjusting common nitrogen sources (urea and melamine) and doping routes, including dry and wet milling, to reach a desirable balance of high capacity, long‐term cyclability, and rate property. The optimized SiO2/NC composite delivers a stably reversible capacity of 581 mA h g−1 at the high current load of 1.0 A g−1 at the 1000th cycle. The novel Li‐storage mechanism of active silica in a composite was first proposed after observation of the N‐doping effect that the redox reaction between SiO2 and Li+ is accelerated to transform into an alloying reaction of generated Si and Li+, thus enhancing the reversible capacity. Moreover, kinetics analysis confirms that there is a combined Li‐storage mechanism of battery‐capacitive pattern in composite that contributes to fast charge transfer and ion diffusion during cycle.
Mixed Cu2Se Hexagonal Nanosheets@Co3Se4 Nanospheres for High‐Performance Asymmetric Supercapacitors
Authors: Li Ang , Zhai Miaomiao , Luan Mingxing , Hu Jingbo 
Published: April 2021

AbstractRational designing and constructing multiphase hybrid electrode materials is an effective method to compensate for the performance defects of the single component. Based on this strategy, Cu2Se hexagonal nanosheets@Co3Se4 nanospheres mixed structures have been fabricated by a facile two‐step hydrothermal method. Under the synergistic effect of the high ionic conductivity of Cu2Se and the remarkable cycling stability of Co3Se4, Cu2Se@Co3Se4 can exhibit outstanding electrochemical performance as a novel electrode material. The as‐prepared Cu2Se@Co3Se4 electrode displays high specific capacitance of 1005 F g−1 at 1 A g−1 with enhanced rate capability (56 % capacitance retention at 10 A g−1), and ultralong lifespan (94.2 % after 10 000 cycles at 20 A g−1). An asymmetric supercapacitor is assembled applying the Cu2Se@Co3Se4 as anode and graphene as cathode, which delivers a wide work potential window of 1.6 V, high energy density (30.9 Wh kg−1 at 0.74 kW kg−1), high power density (21.0 Wh kg−1 at 7.50 kW kg−1), and excellent cycling stability (85.8 % after 10 000 cycles at 10 A g−1).
Self‐Assembly and Aggregation‐Induced Emission in Aqueous Media of Responsive Luminescent Copper(I) Coordination Polymer Nanoparticles
Authors: Hernández‐Toledo Hugo , Torrens Hugo , Flores‐Álamo Marcos , De Cola Luisa , Moreno‐Alcántar Guillermo 
Published: April 2021

AbstractLuminescent copper(I)‐based compounds have recently attracted much attention since they can reach very high emission quantum yields. Interestingly, Cu(I) clusters can also be emissive, and the extension from small molecules to larger architecture could represent the first step towards novel materials that could be obtained by programming the units to undergo self‐assembly. However, for Cu(I) compounds the formation of supramolecular systems is challenging due to the coordinative diversity of copper centers. This works shows that this diversity can be exploited in the construction of responsive systems. In detail, the changes in the emissive profile of different aggregates formed in water by phosphine‐thioether copper(I) derivatives were followed. Our results demonstrate that the self‐assembly and disassembly of Cu(I)‐based coordination polymeric nanoparticles (CPNs) is sensitive to solvent composition. The solvent‐induced changes are related to modifications in the coordination sphere of copper at the molecular level, which alters not only the emission profile but also the morphology of the aggregates. Our findings are expected to inspire the construction of smart supramolecular systems based on dynamic coordinative metal centers.
Quantification and Prediction of Imine Formation Kinetics in Aqueous Solution by Microfluidic NMR Spectroscopy
Authors: Zhuo Youzhen , Wang Xiuxiu , Chen Si , Chen Hang , Ouyang Jie , Yang Liulin , Wang Xinchang , You Lei , Utz Marcel , Tian Zhongqun , Cao Xiaoyu 
Published: April 2021

AbstractQuantitatively predicting the reactivity of dynamic covalent reaction is essential to understand and rationally design complex structures and reaction networks. Herein, the reactivity of aldehydes and amines in various rapid imine formation in aqueous solution by microfluidic NMR spectroscopy was quantified. Investigation of reaction kinetics allowed to quantify the forward rate constantsk+by an empirical equation, of which three independent parameters were introduced as reactivity parameters of aldehydes (SE,E) and amines (N). Furthermore, these reactivity parameters were successfully used to predict the unknown forward rate constants of imine formation. Finally, two competitive reaction networks were rationally designed based on the proposed reactivity parameters. Our work has demonstrated the capability of microfluidic NMR spectroscopy in quantifying the kinetics of label‐free chemical reactions, especially rapid reactions that are complete in minutes.
Bloß kein zweites Asbest
Authors: Packroff Rolf , Broßell Dirk , Meyer‐Plath Asmus , Marx Romy 
Published: April 2021

ZusammenfassungDie Verwendung von Asbest wurde, obwohl die gefährlichen Eigenschaften bereits vor mehr als 120 Jahren erkannt wurden, viel zu spät durch gesetzliche Regelungen eingeschränkt. Mit dem Toxikologischen Faserprinzip wurden die gesundheitlichen Auswirkungen auch wissenschaftlich plausibel und konnten auf Morphologie und Biobeständigkeit eingeatmeter Faserstäube zurückgeführt werden. Damit wurden nicht nur andere Fasermaterialien als potenzielle Kanzerogene identifiziert, sondern auch Ansatzpunkte für ein sicheres Design neuer Fasermaterialien abgeleitet. Die Risikoforschung zu Nanomaterialien hat diese Kenntnisse weiter vertieft und differenziert. Sie müssen nun Grundlage für eine Weiterentwicklung des europäischen Chemikalienrechts werden, um kein zweites Asbest auf dem Binnenmarkt zuzulassen.
Sequence‐Selective Covalent CaaX‐Box Receptors Prevent Farnesylation of Oncogenic Ras Proteins and Impact MAPK/PI3 K Signaling
Authors: Franz Matthias , Mörchen Britta , Degenhart Carsten , Gülden Daniel , Shkura Oleksandr , Wolters Dirk , Koch Uwe , Klebl Bert , Stoll Raphael , Helfrich Iris , Scherkenbeck Jürgen 
Published: April 2021

AbstractOncogenic Ras proteins are implicated in the most common life‐threatening cancers. Despite intense research over the past two decades, the progress towards small‐molecule inhibitors has been limited. One reason for this failure is that Ras proteins interact with their effectors only via protein‐protein interactions, which are notoriously difficult to address with small organic molecules. Herein we describe an alternative strategy, which prevents farnesylation and subsequent membrane insertion, a prerequisite for the activation of Ras proteins. Our approach is based on sequence‐selective supramolecular receptors which bind to the C‐terminal farnesyl transferase recognition unit of Ras and Rheb proteins and covalently modify the essential cysteine in the so‐called CaaX‐box.
Generation of Stable Isopentenyl Monophosphate Aryloxy Triester Phosphoramidates as Activators of Vγ9Vδ2 T Cells
Authors: Xu Qin , Taher Taher E. , Ashby Elizabeth , Sharif Maria , Willcox Benjamin E. , Mehellou Youcef 
Published: April 2021

AbstractAryloxy triester phosphoramidate prodrugs of the monophosphate derivatives of isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) were synthesized as lipophilic derivatives that can improve cell uptake. Despite the structural similarity of IPP and DMAPP, it was noted that their phosphoramidate prodrugs exhibited distinct stability profiles in aqueous environments, which we show is due to the position of the allyl bond in the backbones of the IPP and DMAPP monophosphates. As the IPP monophosphate aryloxy triester phosphoramidates showed favorable stability, they were subsequently investigated for their ability to activate Vγ9/Vδ2 T cells and they showed promising activation of this subset of T cells. Together, these findings represent the first report of IPP and DMAPP monophosphate prodrugs and the ability of IPP aryloxy triester phosphoramidate prodrugs to activate Vγ9/Vδ2 T cells highlighting their potential as possible immunotherapeutics.