bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability and Degradation Mechanisms of Copper‐Based Catalysts for Electrochemical CO2 Reduction
Authors: Popović Stefan , Smiljanić Milutin , Jovanovič Primož , Vavra Jan , Buonsanti Raffaella , Hodnik Nejc 
Published: March 2020

AbstractTo date, copper is the only monometallic catalyst that can electrochemically reduce CO2 into high value and energy‐dense products, such as hydrocarbons and alcohols. In recent years, great efforts have been directed towards understanding how its nanoscale structure affects activity and selectivity for the electrochemical CO2 reduction reaction (CO2RR). Furthermore, many attempts have been made to improve these two properties. Nevertheless, to advance towards applied systems, the stability of the catalysts during electrolysis is of great significance. This aspect, however, remains less investigated and discussed across the CO2RR literature. In this Minireview, the recent progress on understanding the stability of copper‐based catalysts is summarized, along with the very few proposed degradation mechanisms. Finally, our perspective on the topic is given.
Stabile Silanoltriaden im Zeolithkatalysator SSZ‐70
Authors: Schroeder Christian , Mück‐Lichtenfeld Christian , Xu Le , Grosso‐Giordano Nicolás A. , Okrut Alexander , Chen Cong‐Yan , Zones Stacey I. , Katz Alexander , Hansen Michael Ryan , Koller Hubert 
Published: March 2020

AbstractAuf der inneren Porenoberfläche des calcinierten Zeoliths SSZ‐70 wurden Nester mit drei Silanolgruppen gefunden. 2D‐1H‐Doppel‐/Tripelquanten‐Einquanten‐Korrelations‐NMR‐Experimente erlauben eine eindeutige Identifikation dieser Silanoltriadenester. In der hydrothermal synthetisierten Probe zeigen sie auch eine enge Nachbarschaft zu den Strukturdirigenten (structure directing agents, SDAs), den N,N′‐Diisobutylimidazolium‐Kationen, wobei die Defekte zum Ladungsausgleich hier negativ geladen sind (Silanoldyade und eine geladene SiO−‐Siloxygruppe). Infolge der energetisch ungünstigen Ringspannung findet keine Kondensation der Silanolgruppen zu Dreiringen während der Calcination und Entfernung des SDA statt. Dahingegen sind Tetradenester, die durch Extraktion von Bor aus B‐SSZ‐70 an unterschiedlichen Stellen eigentlich entstehen müssten, nicht stabil, und Silanolkondensation findet statt. Untersuchungen mittels Infrarotspektroskopie von adsorbiertem Pyridin zeigen eine erhöhte Acidität der Silanoltriaden, was wichtige Auswirkungen in der Katalyse nahelegt.
Recycling of multilayer packaging using a reversible cross‐linking adhesive
Authors: Kaiser Katharina M. A. 
Published: March 2020

AbstractPlastic‐based multilayer packaging has an important function on the packaging market, but is currently not recyclable as the polymer layers used are usually thermodynamically immiscible. This work therefore follows the approach to prepare separable multilayer packaging using a packaging adhesive modified with thermally unstable adducts, and proposes a corresponding recycling process. For this purpose, typical multilayer structures (polyethylene (PE)// polyethylene terephtalate (PET), PET//aluminum, and PE//aluminum) were prepared by curing furan‐/maleimide‐functionalized polyurethane (PU)‐prepolymers with a three‐functional cross‐linking agent. Adhesions of up to over 3N per 15 mm test specimen were measured or substrate failures of PET films were observed. However, heating in dimethylsulfoxide, the retro‐Diels–Alder reaction takes place and the cross‐linked adhesive turns thermoplastic and dissolves in the solvent. Thus, the laminate separates and the pure PE, PET, and aluminum foils can be recovered without any PU residue.
New thiazolyl‐pyrazoline derivatives bearing nitrogen mustard as potential antimicrobial and antiprotozoal agents
Authors: Cuartas Viviana , Robledo Sara M. , Vélez Iván D. , Crespo María del Pilar , Sortino Maximiliano , Zacchino Susana , Nogueras Manuel , Cobo Justo , Upegui Yulieth , Pineda Tatiana , Yepes Lina , Insuasty Braulio 
Published: March 2020

AbstractA new series of N‐substituted pyrazoline derivatives 6a–g, 7a–g, 8a–g, and 9a–g was synthetized by reaction of hydrazine derivatives and chalcone–thiazole hybrids bearing nitrogen mustard 5a–g. The chalcones 5a–g were obtained by Claisen–Schmidt condensation of thiazole‐2‐nitrogen mustard 3 and selected acetophenones 4a–g. These new compounds 6/7/8/9a–g were screened for their antifungal activity against Cryptococcus neoformans, with IC50 values of 3.9–7.8 µg/ml for the N‐3,5‐dichlorophenyl pyrazolines 9e–g. Interestingly, those compounds show low cytotoxic effects toward erythrocytes (RBC). In addition, N‐acetyl (6a,b) and N‐formyl pyrazolines (7a, 7b, 7c, and 7g) showed inhibitory activity against methicillin‐susceptible Staphylococcus aureus, methicillin‐resistant S. aureus, and vancomycin‐intermediate S. aureus, with the most important minimum inhibitory concentration values ranging from 31.25 to 125 µg/ml. Regarding the antiprotozoal activity, thiazolyl‐pyrazolines 9g, 8f, and 7c display high activity against Plasmodium falciparum, Leishmania (V) panamensis, and Trypanosoma cruzi, with EC50 values of 11.80, 6.46, and 4.98 μM, respectively, and with 7c being approximately 2.6‐fold more potent than benznidazole with a selectivity index of 1.61 on U‐937 human cells, showing promising potential as a novel antitrypanosomal agent.
Dynamics of spherical space debris of different sizes falling to Earth
Authors: Slíz‐Balogh Judit , Horváth Dániel , Szabó Róbert , Horváth Gábor 
Published: March 2020

AbstractSpace debris larger than 1 cm can damage space instruments and impact Earth. The low‐Earth orbits (at heights smaller than 2,000 km) and orbits near the geostationary‐Earth orbit (at 35,786 km height) are especially endangered because most satellites orbit at these latitudes. With current technology, space debris smaller than 10 cm cannot be tracked. Smaller space debris fragments burn up and evaporate in the atmosphere, but larger ones fall to Earth's surface. For practical reasons, it would be important to know the mass, composition, shape, velocity, direction of motion, and impact time of space debris re‐entering the atmosphere and falling to Earth. Since it is very difficult to measure these physical parameters, almost nothing is known about them. To partly fill this gap, we performed computer modeling with which we studied the dynamics of spherical re‐entry particles falling to Earth due to air drag. We determined the time, velocity, and angle of impact as functions of the launch height, direction, speed, and size of spherical re‐entry particles. Our results can also be used for semispherical meteoroid particles of the interplanetary dust entering the Earth's atmosphere.
Applicability of the Øie‐Tozer model to predict three types of distribution volume (Vd) in humans: Vd in central compartment, Vd at steady state, and Vd at beta phase
Authors: Yahata Masahiro , Ishii Yuji , Nakagawa Tetsuya , Watanabe Takao , Miyawaki Izuru 
Published: March 2020

AbstractThis study aimed to investigate the applicability of the Øie‐Tozer model to predict human distribution volume (Vd) in the central compartment (V1), Vd at steady state (Vdss), and Vd at beta phase (Vdβ) based on animal Vd. Twenty compounds that have a human V1/Vdss of 0.053–0.66 were selected from the literature. After intravenous administration of the compounds at 0.1 mg/kg to rats, dogs, and monkeys, plasma concentrations were determined, and pharmacokinetic parameters were obtained by one/two‐compartmental analyses. The human V1, Vdss, and Vdβ were predicted from animal Vd using the Øie‐Tozer model, and the predictability was compared with that using proportionality and simple allometry. The Øie‐Tozer model was the most reliable method for the overall prediction of Vd and applicable for accurately predicting human V1, Vdss, and Vdβ (89%, 85%, and 68% of the compounds within a 3‐fold error, respectively) when data of monkey for V1 and data of three animal species for Vdss and Vdβ were used. Additionally, the predicted human Vd with the two‐compartment model was applicable for predicting pharmacokinetic profiles/parameters in humans after intravenous administration of 18 compounds [except for valproic acid (monophasic elimination profile) and chlorpromazine (deviation: Vdss < V1)]. The prediction was more accurate than that using the predicted Vdss with the one‐compartment model (e.g., underestimation of maximum plasma concentrations: 2 vs 8 compounds within a 3‐fold error, respectively). In summary, the Øie‐Tozer model was applicable for predicting human V1, Vdss, and Vdβ, and their predicted Vd with the two‐compartment model can lead to accurate pharmacokinetic prediction of compounds that show biphasic elimination.
Caffeoylquinic Acids, Cytotoxic, Antioxidant, Acetylcholinesterase and Tyrosinase Enzyme Inhibitory Activities of Six Inula Species from Bulgaria
Authors: Trendafilova Antoaneta , Ivanova Victoria , Rangelov Miroslav , Todorova Milka , Ozek Gulmira , Yur Suleyman , Ozek Temel , Aneva Ina , Veleva Ralitza , Moskova‐Doumanova Veselina , Doumanov Jordan , Topouzova‐Hristova Tanya 
Published: March 2020

AbstractChlorogenic (5‐CQA), 1,5‐, 3,5‐, 4,5‐ and 3,4‐dicaffeoylquinic (DCQA) acids were identified and quantified in the methanol extracts of Inula oculus‐christi L., I. bifrons L., I. aschersoniana Janka var. aschersoniana, I. ensifolia L., I. conyza (Griess.) DC. and I. germanica L. by HPLC analysis. The amount of 5‐CQA varied from 5.48 to 28.44 mg/g DE and the highest content was detected in I. ensifolia. 1,5‐DCQA (4.05–55.25 mg/g DE) was the most abundant dicaffeoyl ester of quinic acid followed by 3,5‐DCQA, 4,5‐DCQA and 3,4‐DCQA. The extract of I. ensifolia showed the highest total phenolic content (119.92±0.95 mg GAE/g DE) and exhibited the strongest DPPH radical scavenging activity (69.41±0.55 %). I. bifrons extract was found to be the most active sample against ABTS.+ (TEAC 0.257±0.012 mg/mL) and the best tyrosinase inhibitor. The studied extracts demonstrated a low inhibitory effect towards acetylcholinesterase and possessed low cytotoxicity in concentration range from 10 to 300 μg/mL toward non‐cancer (MDCK II) and cancer (A 549) cells.
Effectiveness of the “new rope coil” composite core Suoh 0.3 guidewire in the management of coronary artery dissections
Authors: Gasparini Gabriele L. , Sanz Sanchez Jorge , Gagnor Andrea , Mazzarotto Pietro 
Published: March 2020

AbstractCoronary artery dissection is a well‐known complication of percutaneous coronary interventions. In this setting, coronary artery dissection is caused by mechanical injury of the arterial wall. However, dissection may also occur spontaneously. In both situations, an intimal tear or dissection allows blood entering and separating the layers of the coronary arterial wall. Despite percutaneous approach is still the preferred and the quickest way to restore coronary flow, it remains challenging. One of the main reasons for procedural failure is due to the difficult advancement of a guidewire into the true lumen. In such situation, the ideal wire should have a soft tip, high torque control, and excellent flexibility. Assuming that, the “new rope coil” composite core Suoh 0.3 guidewire, with its unique combination of characteristics, could allow better orientation insight into a dissected coronary artery increasing the chance of procedural success. We collected a case series of nine consecutive patients in which the Suoh 0.3 guidewire was able to gain the true lumen distally to a dissected segment.
Which Stereoinductor Is Better for Asymmetric Functionalization of α‐Amino Acids in a Nickel(II) Coordination Environment? Experimental and DFT Considerations
Authors: Levitskiy Oleg A. , Aglamazova Olga I. , Soloshonok Vadim A. , Moriwaki Hiroki , Magdesieva Tatiana V. 
Published: March 2020

AbstractThe results of extended comparative investigation of nickel(II) Schiff base complexes (containing various auxiliary chiral moieties) commonly used as a methodological platform for the asymmetric synthesis of tailor‐made α‐amino acids are provided. The following issues are addressed: 1) redox activity (determining the possibility for electrochemically induced reactions); 2) quantitative estimation of the reactivity of deprotonated complexes towards electrophiles; and 3) quantum‐chemical estimation of noncovalent interactions in the metal coordination environment (which shed light on the origin of the stereochemical outcome observed for different stereoinductors). Possible mechanisms that determine the relationship between the stereochemical configuration of a molecule and its electronic structure are discussed. The DFT‐calculated HOMO–LUMO energies and localization, as well as relative energies for the (S)‐ and (R)‐alanine derivatives, that determine the stereoinduction efficiency in thermodynamically controlled reactions in nickel(II) coordination are provided. The computational data are supported by experimental results on the monobenzylation of glycine derivatives.
Imidazo[1,2‐a]pyridine as an Electron Acceptor to Construct High‐Performance Deep‐Blue Organic Light‐Emitting Diodes with Negligible Efficiency Roll‐Off
Authors: Zheng Xu‐Hui , Zhao Jue‐Wen , Chen Xiang , Cai Ruoke , Yang Guo‐Xi , Zhu Jie‐Ji , Tang Shan‐Shun , Lin Zhi‐Hong , Tao Si‐Lu , Tong Qing‐Xiao 
Published: March 2020

AbstractTwo novel bipolar deep‐blue fluorescent emitters, IP‐PPI and IP‐DPPI, featuring different lengths of the phenyl bridge, were designed and synthesized, in which imidazo[1,2‐a]pyridine (IP) and phenanthroimidazole (PI) were proposed as an electron acceptor and an electron donor, respectively. Both of them exhibit outstanding thermal stability and high emission quantum yields. All the devices based on these two materials showed negligible efficiency roll‐off with increasing current density. Impressively, non‐doped organic light‐emitting diodes (OLEDs) based on IP‐PPI and IP‐DPPI exhibited external quantum efficiencies (EQEs) of 4.85 % and 4.74 % with CIE coordinates of (0.153, 0.097) and (0.154, 0.114) at 10000 cd m−2, respectively. In addition, the 40 wt % IP‐PPI doped device maintained a high EQE of 5.23 % with CIE coordinates of (0.154, 0.077) at 10000 cd m−2. The doped device based on 20 wt % IP‐DPPI exhibited a higher deep‐blue electroluminescence (EL) performance with a maximum EQE of up to 6.13 % at CIE of (0.153, 0.078) and maintained an EQE of 5.07 % at 10000 cd m−2. To the best of our knowledge, these performances are among the state‐of‐the art devices with CIEy≤0.08 at a high brightness of 10000 cd m−2. Furthermore, by doping a red phosphorescent dye Ir(MDQ)2 (MDQ=2‐methyldibenzo[f,h]quinoxaline) into the IP‐PPI and IP‐DPPI hosts, high‐performance red phosphorescent OLEDs with EQEs of 20.8 % and 19.1 % were achieved, respectively. This work may provide a new approach for designing highly efficient deep‐blue emitters with negligible roll‐off for OLED applications.
Functionalization of a Single C−F Bond of Trifluoromethylarenes Assisted by an ortho‐Silyl Group Using a Trityl‐Based All‐in‐One Reagent with Ytterbium Triflate Catalyst
Authors: Kim Youngchan , Kanemoto Kazuya , Shimomori Ken , Hosoya Takamitsu , Yoshida Suguru 
Published: March 2020

AbstractCatalytic thiolation and azidation of a single C−F bond of trifluoromethylarenes were achieved assisted by an ortho‐silyl group with all‐in‐one reagents to generate a trityl cation and nucleophiles. The reactions catalyzed by ytterbium triflate efficiently afforded a wide variety of difluoromethylenes avoiding the further C−F bond cleavage, by virtue of the mild conditions without the generation of a Brønsted acid.
Alexander von Humboldt als Chemiker
Authors: Gröger Martin , Wurm Katharina 
Published: March 2020

ZusammenfassungAlexander von Humboldt war in zahlreichen Forschungsgebieten aktiv – auch auf dem Gebiet der Chemie. Uns scheint eine unterrichtliche Thematisierung von Humboldts chemischen Forschungsarbeiten für wissenschaftshistorische und wissenschaftstheoretische Betrachtungen, aber auch mit Blick auf aktuelle Bezüge zum Klimawandel sowie eigenständiges kreatives Experimentieren der Lernenden gewinnbringend.
A Novel Route to Synthesize N,N‐Dimethyl Arylmethylamines from Aryl Aldehydes, Hexamethylenetetramine and Hydrogen†
Authors: Ke Zhengang , Yu Bo , Wu Yunyan , Zhao Yanfei , Yang Peng , Guo Shien , Liu Zhimin 
Published: March 2020

Summary of main observation and conclusionDeveloping simple and green routes to access valuable chemicals is of significance. Herein, we present a green and novel route to synthesize N,N‐dimethyl arylmethylamines (DAMAs) from hexamethylenetetramine (HMTA) and aryl aldehydes in the presence of hydrogen, and a series of DAMAs can be obtained in good yields. This approach opens the precedent for HMTA as N,N‐dimethylamine source to synthesize chemicals with N,N‐dimethylamine group, which has promising applications for N‐containing chemicals synthesis.
Boosting Photocatalytic Activity in Cross‐Coupling Reactions by Constructing Pd‐Oxide Heterostructures
Authors: Wu Di , Li Zheyue , Qi Zeming , Hu Shanwei , Long Ran , Song Li , Xiong Yujie 
Published: March 2020

AbstractThe design of heterogeneous photocatalysts for organic synthesis has attracted great attention for achieving enhanced catalytic performance under light illumination. However, the effects of photocatalytic processes on organic reactions are quite complicated. In this work, we construct a series of Pd‐oxide heterostructures and then evaluate their catalytic performances on cross‐coupling reactions. The investigation results reveal that the conduction type of the oxide supports critically influences the catalytic efficiency via charge density control of metallic sites. In general, an n‐type semiconductor enhances the catalytic performance while a p‐type reduces the catalytic activity in the presence of suitable illumination conditions. Further investigation on the Pd tetrahedron‐TiO2 nanosheet hybrid structure reveals that Heck reactions take place via a radical intermediate mechanism in the presence of light, leading to a significant increase in the catalytic performance.
Drug Release from Polymer Thin Films and Gel Pellets: Insights from Programmed Microplate Electroanalysis
Authors: Ruff Adrian , Jaikaew Wajee , Khunkaewla Panida , Schuhmann Wolfgang , Schulte Albert 
Published: March 2020

AbstractRobotic electroanalysis in 24‐well microplates was used to determine Paracetamol (PCT) release from thin films of chitosan and two pH‐sensitive synthetic polymers as well as blends of the polymers with each other and with agarose. Square‐wave voltammograms were recorded automatically in a potential window of 0.35 V–0.85 V vs. Ag/AgCl/0.1 M KCl and their evaluation revealed time‐dependent PCT release into acidic and basic media. Comparison of the release profiles showed that pure chitosan layers released PCT quickly in a single‐phase process while liberation from synthetic polymer thin films was slower with a sigmoidal shape at pH 1.2 and pH 8.0 with a maximum release of PCT after approximately 150 and 140 min, respectively. The release profile from thicker agarose films was between those of the thin films. Agarose blended with chitosan or synthetic polymers formed films with biphasic release behavior. Chitosan linearized the initial section of the release profile in chitosan/polymer blends. The automated procedure for release testing offers the advantage of low‐cost, labor‐effective and error‐free data acquisition. The procedure has been validated as a useful microplate assay option for release profile testing.
Identification of seedling resistance to stem rust in advanced wheat lines and varieties from Pakistan
Authors: Rehman Monsif Ur , Gale Sam , Brown‐Guedira Gina , Jin Yue , Marshall David , Whitcher Lynda , Williamson Sharon , Rouse Matthew , Ahmad Javed , Ahmad Gulzar , Shah Irfan Ahmad , Sial Mahboob Ali , Rauf Yahya , Rehman Rattu Atiq Ur , Mirza Javed Iqbal , Ward Rick , Nadeem Majid , Ullah Ghulam , Imtiaz Muhammad 
Published: March 2020

AbstractStem rust is a major disease of wheat (Triticum aestivum L.) worldwide and new Puccinia graminis f. sp. tritici (Pgt) races including TTKSK (Ug99) pose a serious threat to wheat production. The protection of new varieties against Pgt races can be increased by identifying and combining several types of stem rust resistance genes (Sr). We screened a set of 707 wheat lines and cultivars against 11 Pgt races under glass house conditions. Of the tested lines, groups of 99, 513, 289, and 515 exhibited low infection type (IT < 3) to races TTKSK, TRTTF, TTTTF, and RRTTF, respectively. Screening against Pgt races (QFCSC, QTHJC, MCCFC, RCRSC, RKRQC, TPMKC, and QCCSM) showed that most of the tested lines were resistant. These lines were screened with eight DNA markers for the presence of Sr2, Sr9a, Sr24, Sr25, Sr31, Sr36, Sr38, and Sr57 genes. Sr36 was absent from all the tested lines, whereas Sr9a was detected in four lines. The marker Sr2_ger93p predicted the presence of Sr2 in 40 lines, and marker barc71 suggested the presence of Sr24 in 12 lines. Sr25 and Sr38 were present in 13 and 54 lines, respectively. The highest frequency of Sr genes was observed for Sr57 (199 lines) and Sr31 (177 lines). Except for lines carrying Sr25 and/or Sr24 genes, most lines were susceptible to Pgt race TTKSK. Since Ug99 is overcoming Sr genes worldwide, including Sr24 and Sr36, a strategy to pyramid multiple Sr genes in new cultivars should be pursued to achieve a durable control of stem rust. The effectiveness of lines such as NRL0902, 11050, B‐2(RF)‐11, and CCRI‐6, found in the current study and featuring other Sr genes, warrants further investigation to identify the source of their resistance and use it in Pakistan wheat breeding programs.
The fungal endophyte Epichloë festucae var. lolii plays a limited role in mediating crown rust severity in perennial ryegrass
Authors: Heineck Garett C. , Qiu Yinjie , Ehlke Nancy J. , Watkins Eric 
Published: March 2020

AbstractPerennial ryegrass (Lolium perenne L.) is an important turf and forage species that often becomes infected with Puccinia coronata f. sp. lolii, the causal pathogen of crown rust. Disease control through clavicipitaceous endophytes has been proposed as a potential biocontrol. Two field experiments were designed to determine the influence of native Epichloë endophyte infection on natural rust development across a diverse panel of perennial ryegrass germplasm. Experiment 1 used an isogenic population design in which infected (E+) or endophyte‐free (E−) clonal plants were nested within 14 perennial ryegrass entries. Experiment 2 consisted of isofrequent E+ and E− progeny from isogenic parents. Results showed the endophyte had no consistent main effect on crown rust severity among or within entries; however, several isogenic host pairs did show either favorable or antagonistic effects. Despite these sporadic effects, no differences were found between isofrequent family pairs, indicating the presence of a host × endophyte interaction. Genotypic and phenotypic data revealed that endophyte isolates were similar within entry, indicating that host genotype could be responsible for the highly specific endophyte effect on crown rust. The preponderance of host resistance in mediating rust severity was supported by large broad (>.75) and narrow‐sense (.76) heritability estimates. These findings support the conclusion that endophyte infection does not play a substantial role in mediating crown rust severity on a population scale in perennial ryegrass.