bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genomics‐Driven Discovery of NO‐Donating Diazeniumdiolate Siderophores in Diverse Plant‐Associated Bacteria
Authors: Hermenau Ron , Mehl Jule L. , Ishida Keishi , Dose Benjamin , Pidot Sacha J. , Stinear Timothy P. , Hertweck Christian 
Published: July 2019

AbstractSiderophores are key players in bacteria–host interactions, with the main function to provide soluble iron for their producers. Gramibactin from rhizosphere bacteria expands siderophore function and diversity as it delivers iron to the host plant and features an unusual diazeniumdiolate moiety for iron chelation. By mutational analysis of the grb gene cluster, we identified genes (grbD and grbE) necessary for diazeniumdiolate formation. Genome mining using a GrbD‐based network revealed a broad range of orthologous gene clusters in mainly plant‐associated Burkholderia/Paraburkholderia species. Two new types of diazeniumdiolate siderophores, megapolibactins and plantaribactin were fully characterized. In vitro assays and in vivo monitoring experiments revealed that the iron chelators also liberate nitric oxide (NO) in plant roots. This finding is important since NO donors are considered as biofertilizers that maintain iron homeostasis and increase overall plant fitness.
Reconstitution of Iterative Thioamidation in Closthioamide Biosynthesis Reveals Tailoring Strategy for Nonribosomal Peptide Backbones
Authors: Dunbar Kyle L. , Dell Maria , Molloy Evelyn M. , Kloss Florian , Hertweck Christian 
Published: July 2019

AbstractThioamide‐containing nonribosomal peptides (NRPs) are exceedingly rare. Recently the biosynthetic gene cluster for the thioamidated NRP antibiotic closthioamide (CTA) was reported, however, the enzyme responsible for and the timing of thioamide formation remained enigmatic. Here, genome editing, biochemical assays, and mutational studies are used to demonstrate that an Fe‐S cluster containing member of the adenine nucleotide α‐hydrolase protein superfamily (CtaC) is responsible for sulfur incorporation during CTA biosynthesis. However, unlike all previously characterized members, CtaC functions in a thiotemplated manner. In addition to prompting a revision of the CTA biosynthetic pathway, the reconstitution of CtaC provides the first example of a NRP thioamide synthetase. Finally, CtaC is used as a bioinformatic handle to demonstrate that thioamidated NRP biosynthetic gene clusters are more widespread than previously appreciated.
Halogen Bonding Increases the Potency and Isozyme Selectivity of Protein Arginine Deiminase 1 Inhibitors
Authors: Mondal Santanu , Gong Xuefeng , Zhang Xiaoqian , Salinger Ari J. , Zheng Li , Sen Sudeshna , Weerapana Eranthie , Zhang Xuesen , Thompson Paul R. 
Published: July 2019

AbstractProtein arginine deiminases (PADs) hydrolyze the side chain of arginine to form citrulline. Aberrant PAD activity is associated with rheumatoid arthritis, multiple sclerosis, lupus, and certain cancers. These pathologies established the PADs as therapeutic targets and multiple PAD inhibitors are known. Herein, we describe the first highly potent PAD1‐selective inhibitors (1 and 19). Detailed structure–activity relationships indicate that their potency and selectivity is due to the formation of a halogen bond with PAD1. Importantly, these inhibitors inhibit histone H3 citrullination in HEK293TPAD1 cells and mouse zygotes with excellent potency. Based on this scaffold, we also developed a PAD1‐selective activity‐based probe that shows remarkable cellular efficacy and proteome selectivity. Based on their potency and selectivity we expect that 1 and 19 will be widely used chemical tools to understand PAD1 biology.
A study on the chemical state of carbon present in fine ash from gasification
Authors: Zhang Yuanchun , Li Hanxu , Gao Shengtao , Geng Yan , Wu Chengli 
Published: July 2019

AbstractTaking feed coal as a reference, the chemical states, content changes, microstructure, distribution, and graphitizable extent of carbon present in gasification fine ash were investigated in detail. The results show that the fine ash includes a significant amount of unreacted carbon. The C1s spectrum is composed of four components in which the contents of C–C and C–H decrease dramatically and graphitized carbon (39.1%) presents. The elemental carbon primarily distributes on the layer structure, whereas elemental silicon and aluminum are mainly found on spherical particles embedded in the layer structure. After gasification, carbon atoms in gasification fine ash are arranged in an orderly manner, and the extent of graphitization of carbon increases, which indicates that carbon in feed coal may be partly graphitized and deposited in fine ash during gasification process.
Polypropylene microfibers via solution electrospinning under ambient conditions
Authors: Acik Gokhan , Altinkok Cagatay 
Published: July 2019

ABSTRACTUniform beadless fibers of chlorinated polypropylene (PP‐Cl) are prepared by electrospinning of PP‐Cl solutions in tetrahydrofuran at different concentrations, feed rates, applied voltages, and tip‐to‐collector distances (TCDs) under ambient conditions for the first time. Average fiber diameter and morphology of the electrospun PP‐Cl fibers are determined by scanning electron microscopy. On the other hand, the wettability of the fibers is examined by water contact angle (WCA) measurements. Furthermore, thermal behavior of fibers is investigated by differential scanning calorimetry and thermogravimetric analyses, respectively. Obtained results show that the higher concentrations and feed rates of polymer solutions not only enhance the average diameter of the electrospun fibers ranging from 2.2 ± 0.5 to 2.8 ± 0.3 μm but improve the hydrophobicity of the fiber surfaces from 128° ± 1.1 to 141° ± 1.0 as well. On the other hand, when applied voltage is increased or TCD is decreased, diameters of achieved fibers are enhanced. It is suggested that PP‐Cl is an useful material for solution electrospinning process at under ambient conditions, exhibiting great scientific merit and good industrial expectation in the potential PP applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 48199.
Socio‐demographic drivers and public perceptions of consumption and conservation of Asian horseshoe crabs in northern Beibu Gulf, China
Authors: Fu Yijian , Huang Shuyan , Wu Zhou , Wang Chun‐Chieh , Su Meidan , Wang Xueping , Xu Peng , Huang Xing , Wu Haiping , Wang Yujun , Wang Jingzhen , Xiao Xiaobo , Zhou Haichao , Xie Xiaoyong , Chen Mo , Huang Shiang‐Lin , Liao Yongyan , Kwan Kit Yue 
Published: July 2019

Abstract

Overharvesting Asian horseshoe crabs for food is a primary threat to their populations. In the present study, 451 residents were interviewed from the northern Beibu Gulf, the coastal area that is believed to accommodate the highest density of the Chinese horseshoe crab Tachypleus tridentatus worldwide, to obtain baseline information on their consumption behaviour and underlying drivers.
Based on the survey data, it is estimated that a mean individual consumption rate of ten meals per year. Nearly half of the respondents (49.7%) claimed that they had previously eaten at least two horseshoe crab meals.
Among the six occupation categories (managers, professionals, workers, environmental‐related workers, fishers and farmers, and students), fishers and farmers were identified as the group that had eaten a significantly higher number of horseshoe crab meals, had consumed them more frequently, and had a greater intention of eating them than that of students. The age, education level, and salary of participants were the important socio‐demographic variables related to their consumption behaviour. More than one‐third of respondents decided to consume horseshoe crabs because they perceived them as tasty ‘seafood’ and valuable ingredients of traditional Chinese medicine.
Eighty‐three per cent of participants reported an overall decrease in the number of horseshoe crabs in the region.
Although the community was supportive towards horseshoe crab conservation, their ecological knowledge of horseshoe crabs was limited. The findings may be useful for providing insights to merge the gap between scientific data and management planning for the horseshoe crab population in the region. Conservation management initiatives, such as the involvement of fishers in monitoring and enforcement, developing a reporting system for landings and by‐catch, and implementing long‐term conservation education through the school curriculum could promote the protection and management of the population.
Almost periodic motion planning and control for double rotary pendulum with experimental validation
Authors: Wang Zeguo , Freidovich Leonid B. , Zhang Honghua 
Published: July 2019

AbstractThe aim is to develop a systematic procedure for planning feasible motions for a double rotary pendulum. This pendulum has one directly actuated horizontal link and two passive links, moving in a rotating vertical plane. We plan a nontrivial oscillatory motion for the passive links that is consistent with the horizontal link rotating at a given average speed and also design a stabilizing controller to approximately induce such a motion. For the motion planning, a numerical optimization procedure is proposed in the form of a sequence of three simpler problems to systematically derive initial guesses for the final optimization search. For the controller design, firstly the system is linearized along a nominal trajectory, and then a parametrized family of candidate stabilizing controllers is designed. For each set of parameters, a necessary and sufficient stability condition can be checked for the derived linear time varying periodic system. Therefore, a numerical optimization procedure is used to find the controller gain for the linear system based on the stability condition. The performance of the closed‐loop system is illustrated via numerical simulations and verified via experiments with an educational platform produced by PendCon, demonstrating achieving oscillations with required characteristics. However, the formal proofs for convergence and even for existence of almost periodic solutions are left for future studies.
Abwasserkanal Emscher – Pumpwerk Oberhausen
Authors: Kühnel Markus , Siepenkötter Johannes , Althoff Marc , Siegel Rainer , Schürmanns Marco , Bader Anne , Fritschi Niklaus 
Published: July 2019

AbstractBei dem Generationenprojekt Emscher‐Umbau werden durch die Emschergenossenschaft drei große Abwasserpumpwerke errichtet. Mit den Bauarbeiten des größten Pumpwerks in Oberhausen wurde Anfang 2016 begonnen, die Fertigstellung wird für Ende 2020 angestrebt.Das Pumpwerk Oberhausen fördert zukünftig die ankommende Abwassermenge von max. 15,3 m3/s aus einer Tiefe von rd. 40 m, die Jahresfördermenge wird bei rd. 160 Mio. m3 liegen.Auf dem Weg bis zu seiner Fertigstellung bildet das Pumpwerk einige Herausforderungen für alle Projektbeteiligten, die es gemeinschaftlich zu bewältigen gilt. In erster Linie sind neben einem technisch sehr anspruchsvollen Bauwerk die engen zeitlichen Vorgaben zu sehen, um das vorgegebene Ziel der Abwasserfreiheit in 2021 sicherstellen zu können.Zu nennen sind hier weiterhin die Anbindung der beiden in Tübbingbauweise erstellten Abwasserkanäle an das zu erstellende Bauwerk, Anforderungen hinsichtlich des Korrosionsschutzes der Bauteile, die geforderte hohe Qualität an die Planung zur Sicherstellung eines möglichst störungsfreien Bauablaufs, die vorausschauende Klärung der Schnittstellen, insbesondere der Lose Bau, M‐ und E‐Technik, sowie eine koordinierte Arbeitsvorbereitung und qualitativ hochwertige Umsetzung der Leistungen durch die ausführende Baufirma.Das Pumpwerk Oberhausen dient der Emschergenossenschaft auch als Pilotprojekt für die Anwendung der BIM‐Methodik, welche als weiteres Hilfsmittel zur Einhaltung der anspruchsvollen Projektvorgaben genutzt werden kann.Die Lage des Pumpwerks am Beginn des zukünftigen ökologischen Schwerpunkts des Holtener Bruchs hat die Emschergenossenschaft bewogen, den Standort architektonisch‐gestalterisch hervorzuheben und als Landmarke zu gestalten.
Planung und Umsetzung von fünf großen Bauprojekten an der Dortmund‐Ems‐Kanal‐Nordstrecke
Authors: Maßmann Birgit , Neif Simon , Renze Helmut 
Published: July 2019

AbstractDie Nordstrecke des Dortmund‐Ems‐Kanals (DEK), auch „Schleusentreppe Rheine“ genannt, beinhaltet auf einem Streckenabschnitt von 29 km die großen Schleusen Bevergern, Rodde, Venhaus, Hesselte und Gleesen. Die Bauwerke sind rd. 100 Jahre alt und müssen in den kommenden Jahren durch Neubauten ersetzt werden. Die neuen Schleusenbauwerke erhalten Kammern mit 140 m Nutzlänge und 12,50 m Breite. Die Schleusen Bevergern und Gleesen am Anfang und am Ende der Schleusentreppe sind als Sparschleusen in Massivbauweise vorgesehen.Maßgebenden Einfluss auf die Planung und die Vergabe haben die z. T. noch laufenden Planfeststellungsverfahren in den beiden Bundesländern, Standardisierungsanforderungen sowie übergeordnete Zwänge aus dem standortübergreifenden Bodenmanagement.Als zusätzliche Anforderung waren nach Abschluss der Entwurfsbearbeitung Gleesen aktuelle Erkenntnisse zur Grundwasserbelastung aus kalklösender Kohlensäure zu berücksichtigen. Dies machte eine grundlegende Überarbeitung der Planungs‐ und Vergabeunterlagen, insbesondere für die Verankerungselemente der Schleusenbaugrube, der Sparbeckenkonstruktion sowie der Uferwände in den Vorhäfen, erforderlich. Die genannten baugrundinduzierten Änderungen hatten unweigerlich Auswirkungen auf Vergabetermine, Bauzeiten und Baukosten.Die einzelnen Schleusenstandorte werden in jeweils drei bis sechs Vergabeeinheiten ausgeschrieben. Hierfür sind eindeutige Bauzwischenzustände zu definieren. Mit der Schleuse Gleesen ging die erste Maßnahme im Rahmen von vier Vergabeverfahren in die Bauausführung. Für den Bauabschnitt 2 – Schleusenanlage samt Nebenbauwerke – erfolgte die Beauftragung im Juli 2018.Neben der Bauausführung werden die Bau‐AN auch mit der Ausführungsplanung beauftragt (Ausnahme: Stahlwasserbau).Durch den Umfang der zu berücksichtigenden Randbedingungen ergeben sich höchste Anforderungen an die Vergabeunterlagen (Genehmigungs‐ und privatrechtliche Forderungen, Geotechnik, Hydrogeologie, Berechnungsgrundlagen, Mindestanforderungen an Nebenangebote etc.) sowie an die vertragliche Gestaltung (Fristen, Schnittstellen, Abnahmen etc.).
Study of luminescence properties of dysprosium‐doped CaAl12O19 phosphor for white light‐emitting diodes
Authors: Dev Kapil , Selot Anupam , Nair Govind B. , Barai Vijay L. , Singh Nitu , Haque Fozia Z. , Aynyas M. , Dhoble S. J. 
Published: July 2019

AbstractDy3+‐doped CaAl12O19 phosphors were synthesized utilizing a combustion method. Crystal structure and morphological examinations were performed respectively using X‐ray diffraction (XRD) and scanning electron microscopy (SEM) techniques to identify the phase and morphology of the synthesized samples. Fourier transform infrared spectroscopy (FTIR) estimations were carried out using the KBr method. Photoluminescence properties (excitation and emission) were recorded at room temperature. CaAl12O19:Dy3+ phosphor showed two emission peaks respectively under a 350‐nm excitation wavelength, centered at 477 nm and 573 nm. Dipole–dipole interaction via nonradiative energy shifting has been considered as the major cause of concentration quenching when Dy3+ concentration was more than 3 mol%. The CIE chromaticity coordinates positioned at (0.3185, 0.3580) for the CaAl12O19:0.03Dy3+ phosphor had a correlated color temperature (CCT) of 6057 K, which is situated in the cool white area. Existing results point out that the CaAl12O19:0.03Dy3+ phosphor could be a favorable candidate for use in white light‐emitting diodes (WLEDs).
Dual stimuli‐responsive polypeptide prepared by thiol‐ene click reaction of poly(l‐cysteine) and N, N‐dimethylaminoethyl acrylate
Authors: Xiao Yan , Tang Chenna , Chen Yang , Lang Meidong 
Published: July 2019

AbstractStimuli‐responsive polymers that can undergo conformational changes with external triggers have enabled themselves as smart materials for various utilizations, among which biodegradability is of particular importance to be engineered for biomedical application. In this study, a thermo and pH dual responsive polypeptide (N, N‐dimethylaminoethyl acrylate‐modified poly(l‐cysteine)) (PLC‐g‐DMAEA) was prepared by the combination of N‐carboxyanhydride ring‐open polymerization and thiol‐ene click chemistry. The biodegradable poly(l‐cysteine) (PLC) with pendant thiol groups provided an easily clickable backbone for postmodification, which was demonstrated by reacting with a well‐known monomer of N, N‐dimethylaminoethyl acrylate (DMAEA) to achieve both temperature and pH responsiveness. The irreversible thermo‐response of PLC‐g‐DMAEA could be attributed to the ordered β‐sheets formed upon heating, leading to the trapped side groups with poor water accessibility. Moreover, this copolymer precipitated at pH ranging from 7.5 to 9.7, but protonation of tertiary amine groups (pH < 7.5) and salt forming of masked thiol groups (pH > 9.7) rendered it soluble in water. Our results revealed that a ready available vinyl monomer could be easily clicked onto the biodegradable PLC and its stimuli responsiveness would be reserved. Moreover, the primary and secondary structures of PLC might influence the conformation, thus leading to the unique responsive behavior of the resulted copolymer.
Structural neuroimaging differentiates vulnerability from disease manifestation in colombian families with Huntington's disease
Authors: Valdés Hernández Maria del C. , Abu‐Hussain Janna , Qiu Xinyi , Priller Josef , Parra Rodríguez Mario , Pino Mariana , Báez Sandra , Ibáñez Agustín 
Published: July 2019

AbstractIntroductionThe volume of the striatal structures has been associated with disease progression in individuals with Huntington's disease (HD) from North America, Europe, and Australia. However, it is not known whether the gray matter (GM) volume in the striatum is also sensitive in differentiating vulnerability from disease manifestation in HD families from a South‐American region known to have high incidence of the disease. In addition, the association of enlarged brain perivascular spaces (PVS) with cognitive, behavioral, and motor symptoms of HD is unknown.Materials and MethodsWe have analyzed neuroimaging indicators of global atrophy, PVS burden, and GM tissue volume in the basal ganglia and thalami, in relation to behavioral, motor, and cognitive scores, in 15 HD patients with overt disease manifestation and 14 first‐degree relatives not genetically tested, which represent a vulnerable group, from the region of Magdalena, Colombia.ResultsPoor fluid intelligence as per the Raven's Standard Progressive Matrices was associated with global brain atrophy (p = 0.002) and PVS burden (p ≤ 0.02) in HD patients, where the GM volume in all subcortical structures, with the exception of the right globus pallidus, was associated with motor or cognitive scores. Only the GM volume in the right putamen was associated with envy and MOCA scores (p = 0.008 and 0.015 respectively) in first‐degree relatives.ConclusionStriatal GM volume, global brain atrophy and PVS burden may serve as differential indicators of disease manifestation in HD. The Raven's Standard Progressive Matrices could be a cognitive test worth to consider in the differentiation of vulnerability versus overt disease in HD.
Octacarbonyl Ion Complexes of Actinides [An(CO)8]+/− (An=Th, U) and the Role of f Orbitals in Metal–Ligand Bonding
Authors: Chi Chaoxian , Pan Sudip , Jin Jiaye , Meng Luyan , Luo Mingbiao , Zhao Lili , Zhou Mingfei , Frenking Gernot 
Published: July 2019

AbstractThe octacarbonyl cation and anion complexes of actinide metals [An(CO)8]+/− (An=Th, U) are prepared in the gas phase and are studied by mass‐selected infrared photodissociation spectroscopy. Both the octacarbonyl cations and anions have been characterized to be saturated coordinated complexes. Quantum chemical calculations by using density functional theory show that the [Th(CO)8]+ and [Th(CO)8]− complexes have a distorted octahedral (D4h) equilibrium geometry and a doublet electronic ground state. Both the [U(CO)8]+ cation and the [U(CO)8]− anion exhibit cubic structures (Oh) with a 6A1g ground state for the cation and a 4A1g ground state for the anion. The neutral species [Th(CO)8] (Oh; 1A1g) and [U(CO)8] (D4h; 5B1u) have also been calculated. Analysis of their electronic structures with the help on an energy decomposition method reveals that, along with the dominating 6d valence orbitals, there are significant 5f orbital participation in both the [An]←CO σ donation and [An]→CO π back donation interactions in the cations and anions, for which the electronic reference state of An has both occupied and vacant 5f AOs. The trend of the valence orbital contribution to the metal–CO bonds has the order of 6d≫5f>7s≈7p, with the 5f orbitals of uranium being more important than the 5f orbitals of thorium.
Intramolecular Ring‐Expansion Reaction (RER) and Intermolecular Coordination of In Situ Generated Cyclic (Amino)(aryl)carbenes (cAArCs)
Authors: Lorkowski Jan , Krahfuß Mirjam , Kubicki Maciej , Radius Udo , Pietraszuk Cezary 
Published: July 2019

AbstractCyclic (amino)(aryl)carbenes (cAArCs) based on the isoindoline core were successfully generated in situ by α‐elimination of 3‐alkoxyisoindolines at high temperatures or by deprotonation of isoindol‐2‐ium chlorides with sodium or copper(I) acetates at low temperatures. 3‐Alkoxy‐isoindolines 2 a,b‐OR (R=Me, Et, iPr) have been prepared in high yields by the addition of a solution of 2‐aryl‐1,1‐diphenylisoindol‐2‐ium triflate (1 a,b‐OTf; a: aryl=Dipp=2,6‐diisopropylphenyl; b: Mesityl‐, Mes=2,4,6‐trimethylphenyl) to the corresponding alcohol (ROH) with NEt3 at room temperature. Furthermore, the reaction of 2 a,b‐OMe in diethyl ether with a tenfold excess of hydrochloric acid led to the isolation of the isoindol‐2‐ium chlorides 1 a,b‐Cl in high yields. The thermally generated cAArC reacts with sulfur to form the thioamide 3 a. Without any additional trapping reagent, in situ generation of 1,1‐diphenylisoidolin‐3‐ylidenes does not lead to the isolation of these compounds, but to the reaction products of the insertion of the carbene carbon atom into an ortho C−H bond of a phenyl substituent, followed by ring‐expansion reaction; namely, anthracene derivatives 9‐N(H)aryl‐10‐Ph‐C14H8 4 a,b (a: Dipp; b: Mes). These compounds are conveniently synthesized by deprotonation of the isoindol‐2‐ium chlorides with sodium acetate in high yields. Deprotonation of 1 a‐Cl with copper(I) acetate at low temperatures afforded a mixture of 4 a and the corresponding cAArC copper(I) chloride 5 a, and allowed the isolation and structural characterization of the first example of a cAArC copper complex of general formula [(cAArC)CuCl].
Denitrogenative Hydrotrifluoromethylation of Benzaldehyde Hydrazones: Synthesis of (2,2,2‐Trifluoroethyl)arenes
Authors: Zhao Zhensheng , Ma Kevin C. Y. , Legault Claude Y. , Murphy Graham K. 
Published: July 2019

AbstractReacting hydrazones of arylaldehydes with Togni's CF3‐benziodoxolone reagent, in the presence of potassium hydroxide and cesium fluoride, induces a denitrogenative hydrotrifluoromethylation event to produce (2,2,2‐trifluoroethyl)arenes. This novel reaction was tolerant to many electronically‐diverse functional groups and substitution patterns, as well as naphthyl‐ and heteroaryl‐derived substrates. Advantages of this process include the easy access to hydrazone precursors on a large scale, speed and operational simplicity, and being transition metal‐free.