bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation interception and leaf area index from foliage cover in diploid potato
Authors: Saldaña‐Villota Tatiana M. , Cotes‐Torres José Miguel 
Published: April 2020

AbstractThe leaf area index (LAI) is defined as the proportion of leaf area per unit of land area. It is also considered as an essential factor in the crop's ability to capture solar energy. Direct methods of LAI estimation involve significant areas of cultivation and individually measuring the total leaf area, which is not an accurate method to assess the LAI in diploid potato (Solanum phureja Juz. et Buk.) cultivars. The objective of this study was to evaluate a practical method for determining the fractional radiation interception and the LAI based on the fractional foliage cover in diploid potato cultivars found using digital photographs and applying open‐source software. Then, we compared the results of this method with the results obtained using a canopy analyzer. The results obtained allow us to estimate foliage and obtain the fractional radiation interception properly, and with these two variables, it is possible to make reasonable estimates of the LAI. It is common to model the LAI, and from this value estimate, the fractional radiation interception. We propose to model the architecture of the plant to know how the diploid potato plant covers the soil in a given space and how much radiation it intercepts, then estimate LAI. This method of estimation would be the closest to the cultivation conditions. Foliage cover depends on the architecture, and the crop simulation model would approximate the plant architecture and not just biomass production and yield.
Immunoglobulin light chain amyloidosis: 2020 update on diagnosis, prognosis, and treatment
Authors: Gertz Morie A. 
Published: April 2020

AbstractDisease OverviewImmunoglobulin light chain amyloidosis is a clonal, nonproliferative plasma cell disorder in which fragments of immunoglobulin light or heavy chain are deposited in tissues. Clinical features depend on organs involved but can include heart failure with preserved ejection fraction, nephrotic syndrome, hepatic dysfunction, peripheral/autonomic neuropathy, and “atypical smoldering multiple myeloma or monoclonal gammopathy undetermined significance (MGUS).”DiagnosisTissue biopsy stained with Congo red demonstrating amyloid deposits with apple‐green birefringence is required for diagnosis. Invasive organ biopsy is not required in 85% of patients. Verification that amyloid is composed of immunoglobulin light chains is mandatory. The gold standard is laser capture mass spectroscopy.PrognosisN‐terminal pro‐brain natriuretic peptide (NT‐proBNP), serum troponin T, and difference between involved and uninvolved immunoglobulin free light chain (FLC) values are used to classify patients into four groups of similar size; median survivals are 94.1, 40.3, 14.0, and 5.8 months.TherapyAll patients with a systemic amyloid syndrome require therapy to prevent deposition of amyloid in other organs and prevent progressive organ failure. Stem cell transplant (SCT) is preferred, but only 20% of patients are eligible. Requirements for safe SCT include systolic blood pressure >90 mmHg, troponin T < 0.06 ng/mL and serum creatinine ≤1.7 mg/dL. Nontransplant candidates can be offered cyclophosphamide‐bortezomib‐dexamethasone or daratumumab‐containing regimens as it appears to be highly active in AL amyloidosis.Future ChallengesDelayed diagnosis remains a major obstacle to initiating effective therapy prior to the development of end‐stage organ failure.
Ein elektronenreiches cyclisches (Alkyl)(amino)carben auf Au(111)‐, Ag(111)‐ und Cu(111)‐Oberflächen
Authors: Bakker Anne , Freitag Matthias , Kolodzeiski Elena , Bellotti Peter , Timmer Alexander , Ren Jindong , Schulze Lammers Bertram , Moock Daniel , Roesky Herbert W. , Mönig Harry , Amirjalayer Saeed , Fuchs Harald , Glorius Frank 
Published: April 2020

AbstractDie strukturellen Eigenschaften und das Bindungsmotiv eines stark σ‐elektronenschiebenden N‐heterocyclischen Carbens werden an verschiedenen Übergangsmetalloberflächen erforscht. Das untersuchte cyclische (Alkyl)(amino)carben (CAAC) erweist sich auf Oberflächen als mobil, und bei hoher Bedeckung konnten molekulare Inseln mit Nahordnung gefunden werden. Durch die Kombination von Rastertunnelmikroskopie (STM), Röntgenphotoelektronenspektroskopie (XPS) und Dichtefunktionaltheorie (DFT) zeigt unsere Studie, wie CAACs an die Oberfläche binden, was für das Verständnis heterogener Katalysatoren, die CAACs als Liganden tragen, von enormer Bedeutung ist.
A Free‐Radical Prompted Barrierless Gas‐Phase Synthesis of Pentacene
Authors: Zhao Long , Kaiser Ralf I. , Lu Wenchao , Ahmed Musahid , Evseev Mikhail M. , Bashkirov Eugene K. , Azyazov Valeriy N. , Tönshoff Christina , Reicherter Florian , Bettinger Holger F. , Mebel Alexander M. 
Published: April 2020

AbstractA representative, low‐temperature gas‐phase reaction mechanism synthesizing polyacenes via ring annulation exemplified by the formation of pentacene (C22H14) along with its benzo[a]tetracene isomer (C22H14) is unraveled by probing the elementary reaction of the 2‐tetracenyl radical (C18H11.) with vinylacetylene (C4H4). The pathway to pentacene—a prototype polyacene and a fundamental molecular building block in graphenes, fullerenes, and carbon nanotubes—is facilitated by a barrierless, vinylacetylene mediated gas‐phase process thus disputing conventional hypotheses that synthesis of polycyclic aromatic hydrocarbons (PAHs) solely proceeds at elevated temperatures. This low‐temperature pathway can launch isomer‐selective routes to aromatic structures through submerged reaction barriers, resonantly stabilized free‐radical intermediates, and methodical ring annulation in deep space eventually changing our perception about the chemistry of carbon in our universe.
Key Intermediate Species Reveal the Copper(II)‐Exchange Pathway in Biorelevant ATCUN/NTS Complexes
Authors: Kotuniak Radosław , Strampraad Marc J. F. , Bossak‐Ahmad Karolina , Wawrzyniak Urszula E. , Ufnalska Iwona , Hagedoorn Peter‐Leon , Bal Wojciech 
Published: April 2020

AbstractThe amino‐terminal copper and nickel/N‐terminal site (ATCUN/NTS) present in proteins and bioactive peptides exhibits high affinity towards CuII ions and have been implicated in human copper physiology. Little is known, however, about the rate and exact mechanism of formation of such complexes. We used the stopped‐flow and microsecond freeze‐hyperquenching (MHQ) techniques supported by steady‐state spectroscopic and electrochemical data to demonstrate the formation of partially coordinated intermediate CuII complexes formed by glycyl–glycyl–histidine (GGH) peptide, the simplest ATCUN/NTS model. One of these novel intermediates, characterized by two‐nitrogen coordination, t1/2≈100 ms at pH 6.0 and the ability to maintain the CuII/CuI redox pair is the best candidate for the long‐sought reactive species in extracellular copper transport.
Expanding the Versatility of Microbial Transglutaminase Using α‐Effect Nucleophiles as Noncanonical Substrates
Authors: Chio Tak Ian , Demestichas Breanna R. , Brems Brittany M. , Bane Susan L. , Tumey L. Nathan 
Published: April 2020

AbstractThe substrate promiscuity of microbial transglutaminase (mTG) has been exploited in various applications in biotechnology, in particular for the attachment of alkyl amines to glutamine‐containing peptides and proteins. Here, we expand the substrate repertoire to include hydrazines, hydrazides, and alkoxyamines, resulting in the formation of isopeptide bonds with varied susceptibilities to hydrolysis or exchange by mTG. Furthermore, we demonstrate that simple unsubstituted hydrazine and dihydrazides can be used to install reactive hydrazide handles onto the side chain of internal glutamine residues. The distinct hydrazide handles can be further coupled with carbonyls, including ortho‐carbonylphenylboronic acids, to form site‐specific and functional bioconjugates with tunable hydrolytic stability. The extension of the substrate scope of mTG beyond canonical amines thus substantially broadens the versatility of the enzyme, providing a new approach to facilitate novel applications.
Efficient Light‐Harvesting Antennae Resulting from the Dense Organization of Dyes into DNA Junctions through d‐Threoninol
Authors: Kashida Hiromu , Azuma Hidenori , Maruyama Ryoko , Araki Yasuyuki , Wada Takehiko , Asanuma Hiroyuki 
Published: April 2020

AbstractHerein we report the construction of efficient light‐harvesting antennae by hybridization of DNA oligonucleotides containing high densities of fluorophores into DNA junctions through d‐threoninol. Six pyrene donors could be incorporated into each arm without self‐quenching. A perylene acceptor was located at the center of the junction. Antenna effects of a duplex and three‐ to eight‐way junctions were systematically compared. Six‐ and eight‐way junctions had the highest antenna effects, and their effective absorption coefficients were 8.5 times higher than that of perylene. Interestingly, even‐numbered junctions had higher efficiencies than odd‐numbered junctions. Nondenaturing gel analyses and fluorescence lifetime measurements demonstrated that the strong odd–even effects were derived from differences in the stability of junctions. The results presented will guide the design of efficient artificial photosynthetic systems.
Reflecting on three creative approaches to informed consent with children under six
Authors: Arnott Lorna , Martinez-Lejarreta Loreain , Wall Kate , Blaisdell Caralyn , Palaiologou Ioanna 
Published: April 2020

In an era when children’s rights are paramount, there are still few practical examples to guide us when seeking informed consent from children. This article therefore makes a significant contribution to the field by examining three practical approaches to negotiating informed consent with young children under 6 years old. We draw on researcher field notes, images and observations from four research projects that employed creative methods for seeking informed consent from young children. We take a reflexive approach, considering how successful the three techniques have been in facilitating young children’s decision‐making around research participation. Our findings suggest that innovative approaches to informed consent create spaces for children to engage in dialogue and questioning about the research project. However, in order for the approaches to be meaningful, they need to be pedagogically appropriate to the maturity and capabilities of the children. We also demonstrate that, irrespective of the approach devised, researchers have a responsibility to ensure consent is continuously negotiated throughout the project through reflexive questioning.
Forster resonance energy transfer for studying nucleic acids denaturation: A chemical and biological sciences laboratory experiment
Authors: Carvalho Josué , Cruz Carla 
Published: April 2020

AbstractThe Förster resonance energy transfer (FRET) melting assay intends to evaluate the unfolding, denaturation process of DNA secondary structures, and its stabilization using compounds known as DNA binders, some of which are highly specific for G‐quadruplex DNAs versus duplex DNAs. First, students determined the melting temperature (Tm) of DNA sequences double labeled with 5′‐FAM (fluorescein) and 3′‐TAMRA (tetramethylrhodamine) in the absence of DNA binders. Second, they determined the melting temperature of the DNAs in the presence of DNA binders by monitoring fluorescence. After completing this experiment, students understood that this method allows a semiquantitative analysis to test a variety of DNA binders against DNA secondary structures, and it can be used to rapidly identify the most promising drug candidates in the drug development stages at the basic research level.
Tuning Nano‐Nickel Catalyst Hydrogenation Aptitude by On‐the‐Fly Zirconium Doping
Authors: Zienkiewicz‐Machnik Małgorzata , Goszewska Ilona , Giziński Damian , Śrębowata Anna , Kuzmowicz Katarzyna , Kubas Adam , Matus Krzysztof , Lisovytskiy Dmytro , Pisarek Marcin , Sá Jacinto 
Published: April 2020

AbstractThe effect of nano‐Ni catalyst post‐synthetic Zr‐modification on hydrogenation reaction of 6‐methyl‐5‐hepten‐2‐one was investigated in a fixed bed continuous‐flow micro‐reactor to produce fine chemicals. The catalytic performance revealed that Zr‐doping achieved by surface organometallic chemistry approach modifies the natural aptitude of nickel to hydrogenate C=C bond, since the addition of small quantities of zirconium significantly increased the amount of unsaturated and saturated alcohols formed in 6‐methyl‐5‐hepten‐2‐one hydrogenation. Quantum chemical calculations revealed a stronger interaction between Zr←O=C that promotes the formation of C=C semihydrogenation product and enhances the probability of complete hydrogenation. The on‐the‐fly strategy presented herein enables for rapid optimization and understanding of catalytic processes.
Anion Recognition by Neutral Chalcogen Bonding Receptors: Experimental and Theoretical Investigation
Authors: Navarro‐García Encarnación , Galmés Bartomeu , Velasco María D. , Frontera Antonio , Caballero Antonio 
Published: April 2020

AbstractInvited for the cover of this issue are the groups of Antonio Frontera at the Universitat de les Illes Balears and Antonio Caballero at the Universidad de Murcia. The image depicts one of the tellurophene based receptors described in this work. Read the full text of the article at 10.1002/chem.201905786.
Synthesis of Symmetrical and Nonsymmetrical Polyenes by Iterative and Bidirectional Palladium‐Catalyzed Cross‐Coupling Reactions
Authors: Rivas Aurea , Areal Andrea , Mora Paula , Álvarez Rosana , de Lera Angel R. 
Published: April 2020

AbstractBifunctional unsaturated reagents designed to undergo palladium‐catalyzed cross‐coupling reactions with complementary polyenyl connective fragments are highly useful for the undoubtedly challenging synthesis of polyenes. The current toolkit of building blocks for the bidirectional formation of Csp2−Csp2single bonds of polyenes includes homo‐bisfunctionalized reagents with equal or unequal reactivity (due to steric and/or electronic factors), and hetero‐bisfunctionalized counterparts containing either two different nucleophiles, two electrophiles or one of these functionalities and a latent nucleophile that can be unmasked when desired. The combination of these bifunctional linchpin reagents using tactics that modulate the reactivity of each terminus in order to achieve the required connection have streamlined the synthesis of polyenes of great complexity using (iterative) cross‐coupling methods for Csp2−Csp2bond formation. Reaction conditions for the Pd‐catalyzed cross‐coupling reactions are mild and functional‐group‐tolerant, and therefore these protocols allow to construct the polyene structures using shorter unsaturated reactants with the desired geometries, since in general the products preserve the stereochemical information of the connected cross‐coupling partners.
Confined Interfacial Synthesis of Highly Crystalline and Ultrathin Graphdiyne Films and Their Applications for N2Fixation
Authors: Kan Xiaonan , Wang Danbo , Pan Qingyan , Wang Yannan , Xiao Yao , Liu Jian , Zhao Yingjie , Li Zhibo 
Published: April 2020

AbstractGraphdiyne (GDY), as a new carbon allotrope, possessing both sp‐ and sp2‐hybridized carbon atoms, has attracted extensive attention due to great application potentials in various fields. To realize a fundamental understanding of the intrinsic properties of GDY, the controllable synthesis of ultrathin and highly crystalline GDY is necessary and challenging. Herein, a confined interfacial synthetic strategy towards highly crystalline ultrathin GDY at the water/oil/organogel interface, with greatly improved control over GDY structures, is reported. The morphology and chemical composition of GDY was characterized accordingly. After loading with gold, the as‐prepared hydrophobic Au/GDY system showed excellent performance in the nitrogen reduction reaction, reaching the highest yield of 4.15 μg cm−2 h−1with a Faraday efficiency of 1.95 %.
Multitarget Compounds for Bipolar Disorder: From Rational Design to Preliminary Pharmacokinetic Evaluation
Authors: Di Martino Rita Maria Concetta , Bottegoni Giovanni , Seghetti Francesca , Russo Debora , Penna Ilaria , De Simone Alessio , Ottonello Giuliana , Mandrup Bertozzi Sine , Armirotti Andrea , Bandiera Tiziano , Belluti Federica , Cavalli Andrea 
Published: April 2020

AbstractDue to the complex and multifactorial nature of bipolar disorder (BD), single‐target drugs have traditionally provided limited relief with no disease‐modifying effects. In line with the polypharmacology paradigm, we attempted to overcome these limitations by devising two series of multitarget‐directed ligands endowed with both a partial agonist profile at dopamine receptor D3 (D3R) and inhibitory activity against glycogen synthase kinase 3 beta (GSK‐3β). These are two structurally unrelated targets that play independent, yet connected, roles in cognition and mood regulation. Two compounds (7 and 10) emerged as promising D3R/GSK‐3β multitarget‐directed ligands with nanomolar activity at D3R and low‐micromolar inhibition of GSK‐3β, thereby confirming, albeit preliminarily, the feasibility of our strategy. Furthermore, 7 showed promising drug‐like properties in stability and pharmacokinetic studies.
Neuroanatomical and neurophysiological mechanisms of acoustic and weakly electric signaling in synodontid catfish
Authors: Kéver Loïc , Bass Andrew H. , Parmentier Eric , Chagnaud Boris P. 
Published: April 2020

AbstractTo what extent do modifications in the nervous system and peripheral effectors contribute to novel behaviors? Using a combination of morphometric analysis, neuroanatomical tract‐tracing, and intracellular neuronal recording, we address this question in a sound‐producing and a weakly electric species of synodontid catfish, Synodontis grandiops, and Synodontis nigriventris, respectively. The same peripheral mechanism, a bilateral pair of protractor muscles associated with vertebral processes (elastic spring mechanism), is involved in both signaling systems. Although there were dramatic species differences in several morphometric measures, electromyograms provided strong evidence that simultaneous activation of paired protractor muscles accounts for an individual sound and electric discharge pulse. While the general architecture of the neural network and the intrinsic properties of the motoneuron population driving each target was largely similar, differences could contribute to species‐specific patterns in electromyograms and the associated pulse repetition rate of sounds and electric discharges. Together, the results suggest that adaptive changes in both peripheral and central characters underlie the transition from an ancestral sound to a derived electric discharge producing system, and thus the evolution of a novel communication channel among synodontid catfish. Similarities with characters in other sonic and weakly electric teleost fish provide a striking example of convergent evolution in functional adaptations underlying the evolution of the two signaling systems among distantly related taxa.
Effect of ploidy level on guard cell length and use of stomata to discard diploids among putative haploids in maize
Authors: da Silva Hingrid Ariane , Scapim Carlos Alberto , Vivas Janieli Maganha Silva , do Amaral Antonio Teixeira , Pinto Ronald José Barth , Mourão Káthia Socorro Mathias , Rossi Robson Marcelo , Baleroni Alessandra Guedes 
Published: April 2020

AbstractGuard cell (GC) length proved to be efficient in sorting diploids from haploids in doubled haploid development in maize (Zea mays L). It compensates for the weakness of widely used R1‐nj marker approach that showed low reliability in haploids identification from tropical genotypes. Guard cell length differs between haploid and diploid plants, and these differences were evaluated in the progeny of three different induction crosses obtained using Krasnodar haploid inducer. Epidermal impressions of the abaxial surface of leaves removed from the second, third, and fourth nodes (from base to apex) were collected and measured using an optical microscope. This was also conducted on the flowering phenotype. Guard cell length varied according to germplasm source, leaf stage, and ploidy level. Mean GC length ranged from 23.67 to 33.82 μm in haploids, and from 36.1 to 41.25 μm in diploids. Based on these differences in GC length at any of the chosen leaf stages (second, third, or fourth), diploid and haploid maize plants were successfully classified. Classification efficiency was found to be more closely related to germplasm source than leaf stage. Comparing GC length according to phenotype (haploid or diploid), GC limits for classification as a diploid plant (threshold points) were estimated and ranged from 29.74 to 34.49 μm, depending on germplasm source. The highest false discovery rate was 2.93% and false negative rate was 15.06%, indicating that classification based on GC length was reliable.
Conducting Redox Polymer as a Robust Organic Electrode‐Active Material in Acidic Aqueous Electrolyte towards Polymer–Air Secondary Batteries
Authors: Oka Kouki , Strietzel Christian , Emanuelsson Rikard , Nishide Hiroyuki , Oyaizu Kenichi , Strømme Maria , Sjödin Martin 
Published: April 2020

AbstractOrganic materials receive increasing attention as environmentally benign and sustainable electrode‐active materials. We present a conducting redox polymer (CRP) based on poly(3,4‐ethylenedioxythiophene) with naphthoquinone pendant group, which is formed from a stable suspension of a trimeric precursor and an oxoammonium cation as oxidant. This suspension allows us to easily coat the polymer onto a current collector, opening up use of roll‐to‐roll processing or ink‐jet printing for electrode preparation. The CRP showed a full capacity of 76 mAh g−1 even at a high C rate of 100 C in acidic aqueous electrolyte. These properties make the CRP a promising candidate as anode‐active material; a polymer–air secondary battery was fabricated with the CRP as anode, a conventional Pt/C catalyst as cathode, and sulfuric acid aqueous solution as electrolyte. This battery yielded a discharge voltage of 0.50 V and showed good cycling stability with 97 % capacity retention after 100 cycles and high rate capabilities up to 20 C.
Catalytic and Atom‐Economic Glycosylation using Glycosyl Formates and Cheap Metal Salts
Authors: Yang Liang , Hammelev Christian H. , Pedersen Christian M. 
Published: April 2020

AbstractBenzylated glycosyl formates have been synthesized in one step from the corresponding hemiacetal or orthoester with formic acid as the sole reagent. The glycosyl formates are used as glycosyl donors under catalytic conditions with cheap metal catalysts based on iron or bismuth. A 13C NMR spectroscopic method is developed and evaluated for screening reactions conditions, giving precise information on the selectivity, yield, and byproducts formed. The major side reaction is transesterification, which gives the formylated acceptor and regenerates the hemiacetal. By using this approach, catalyst loadings and solvents are optimized and the scope of the glycosylation is evaluated for a variety of glycosyl donors and acceptors. A proof of concept for a traceless glycosylation, utilizing a dual‐purpose iron catalyst that catalyzes both glycosylation and dehydrogenation of formic acid, is also provided.