bluuebunny/crossref_metadata_2025_split huggingface dataset:
H2O2‐Triggered Self Immolative Prodrug Nanoassemblies as Self‐Deliverable Nanomedicines for Targeted On‐Demand Therapy of Thrombotic Disorders
Authors: Jung Eunkyeong , Kim Taeeon , Bae Soochan , Kang Peter M. , Lee Dongwon 
Published: April 2021

AbstractFormation of an occlusive thrombus is a critical pathophysiological feature of numerous cardiovascular diseases. Thrombosis is promoted by P‐selectin overexpressed on activated platelets and endothelium and tightly linked with the overproduction of hydrogen peroxide (H2O2). The overexpression of P‐selectin and overproduction of H2O2 become unique features of thrombosed vessels which provide a rationale for the development of targeted therapeutics for thrombosis. In this work, targeted self‐delivering and H2O2‐activatable antithrombotic nanomedicine (Fu–sBR) composed of a self‐immolative dimeric prodrug (sBR) and a P‐selectin targeting fucoidan, are reported. In the presence of fucoidan, sBR is formulated into stable nanoassemblies that can serve as carrier‐free nanodrugs and exert antioxidant, anti‐inflammatory, and antiplatelet activities in a H2O2‐triggered manner. In mouse models of carotid arterial thrombosis and deep vein thrombosis (DVT), Fu–sBR nanoassemblies specifically target thrombosed vessels to effectively suppress thrombus development by inhibiting the expression of tumor necrosis factor‐alpha (TNF‐α), interleukine‐1 beta (IL‐1β), and soluble CD40 ligand (sCD40L). Given their self‐delivering capability, thrombus targeting ability, and stimulus‐activatable therapeutic actions, Fu–sBR nanoassemblies have great translational potential as therapeutic agents for various thrombotic disorders.
Alkyl Phosphine Free, Metal‐Ligand Cooperative Complex Catalyzed Alcohol Dehydrogenative Coupling Reactions
Authors: Roy Bivas Chandra , Ganguli Kasturi , Samim Sk. Abdus , Kundu Sabuj 
Published: April 2021

AbstractIn last two decades alcohol has drawn a special attention as a building blocks due to its abundance, low cost and less toxic nature which can be derived from various sustainable resources. By dehydrogenation of alcohol, aldehyde/ketone can be easily accessed which can be further coupled with several nucleophiles for the construction of complex molecules. Among the various strategies, metal‐ligand cooperation is a powerful and efficient tool for the utilization of alcohol to synthesize variety of value‐added products. Numerous alkyl phosphine based bifunctional complexes are well‐known in the literature for the alcohol dehydrogenative coupling reactions. However, the presence of alkyl phosphine moiety and air and moisture sensitive nature of the metal complexes hinder their broad application in catalysis. In this minireview, we highlighted air and moisture stable, metal‐ligand cooperative 5d, 4d and 3d metal‐based complexes which were effectively utilized to fabricate different value‐added compounds by alcohol dehydrogenative coupling reactions.
Direct α‐Tertiary Alkylations of Ketones in a Combined Copper–Organocatalyst System
Authors: Kurose Ayako , Ishida Yuto , Hirata Goki , Nishikata Takashi 
Published: April 2021

AbstractHerein, we report an efficient method for the tertiary alkylation of a ketone by using an α‐bromocarbonyl compound as the tertiary alkyl source in a combined Cu‐organocatalyst system. This dual catalyst system enables the addition of a tertiary alkyl radical to an enamine. Mechanistic studies revealed that the catalytically generated enamine is a key intermediate in the catalytic cycle. The developed method can be used to synthesize substituted 1,4‐dicarbonyl compounds containing quaternary carbons bearing various alkyl chains.
XFEL Crystal Structures of Peroxidase Compound II
Authors: Kwon Hanna , Basran Jaswir , Pathak Chinar , Hussain Mahdi , Freeman Samuel L. , Fielding Alistair J. , Bailey Anna J. , Stefanou Natalia , Sparkes Hazel A. , Tosha Takehiko , Yamashita Keitaro , Hirata Kunio , Murakami Hironori , Ueno Go , Ago Hideo , Tono Kensuke , Yamamoto Masaki , Sawai Hitomi , Shiro Yoshitsugu , Sugimoto Hiroshi , Raven Emma L. , Moody Peter C. E. 
Published: April 2021

AbstractOxygen activation in all heme enzymes requires the formation of high oxidation states of iron, usually referred to as ferryl heme. There are two known intermediates: Compound I and Compound II. The nature of the ferryl heme—and whether it is an FeIV=O or FeIV‐OH species—is important for controlling reactivity across groups of heme enzymes. The most recent evidence for Compound I indicates that the ferryl heme is an unprotonated FeIV=O species. For Compound II, the nature of the ferryl heme is not unambiguously established. Here, we report 1.06 Å and 1.50 Å crystal structures for Compound II intermediates in cytochrome c peroxidase (CcP) and ascorbate peroxidase (APX), collected using the X‐ray free electron laser at SACLA. The structures reveal differences between the two peroxidases. The iron‐oxygen bond length in CcP (1.76 Å) is notably shorter than in APX (1.87 Å). The results indicate that the ferryl species is finely tuned across Compound I and Compound II species in closely related peroxidase enzymes. We propose that this fine‐tuning is linked to the functional need for proton delivery to the heme.
Siliciumtetrakis(trifluormethansulfonat): Ein einfaches, neutrales Silan als weiche und harte Lewis‐Supersäure
Authors: Hermannsdorfer André , Driess Matthias 
Published: April 2021

AbstractWir berichten über einen einfachen synthetischen Zugang zu donorfreiem Siliciumtetrakis(trifluormethansulfonat), Si(OTf)4, das als erstes neutrales Silan gegenüber weichen und harten Lewis‐Basen eine Lewis‐Supersäure ist. Die OTf‐Substituenten haben dabei zwei Funktionen: Sie sind exzellente Abgangsgruppen und modulieren das Maß an Reaktivität gegenüber weichen und harten Donoren. Mit weichen Lewis‐Basen bildet Si(OTf)4 Komplexe des Typs [L2Si(OTf)4] mit intakten Si‐OTf‐Bindungen (L=Isocyanid‐, Thioether‐ oder Carbonylverbindungen). Im Gegensatz dazu aktiviert das Silan die C‐X‐Bindungen (X=F, Cl) harter organischer Lewis‐Basen unter Halogenid‐Triflat‐Austausch mit einer hohen Neigung zur Bildung von SiX4 (X=F, Cl). Bemerkenswert ist die Oxydefluorierung von Mono‐ und Bis(trifluormethyl)benzolen mit Si(OTf)4 bei milden Bedingungen, wobei entstehende Benzoyliumkationen durch das schwach koordinierende [Si(OTf)6]‐Dianion stabilisiert werden.
Light‐Activation of DNA‐Methyltransferases
Authors: Wolffgramm Jan , Buchmuller Benjamin , Palei Shubhendu , Muñoz‐López Álvaro , Kanne Julian , Janning Petra , Schweiger Michal R. , Summerer Daniel 
Published: April 2021

Abstract5‐Methylcytosine (5mC), the central epigenetic mark of mammalian DNA, plays fundamental roles in chromatin regulation. 5mC is written onto genomes by DNA methyltransferases (DNMT), and perturbation of this process is an early event in carcinogenesis. However, studying 5mC functions is limited by the inability to control individual DNMTs with spatiotemporal resolution in vivo. We report light‐control of DNMT catalysis by genetically encoding a photocaged cysteine as a catalytic residue. This enables translation of inactive DNMTs, their rapid activation by light‐decaging, and subsequent monitoring of de novo DNA methylation. We provide insights into how cancer‐related DNMT mutations alter de novo methylation in vivo, and demonstrate local and tuneable cytosine methylation by light‐controlled DNMTs fused to a programmable transcription activator‐like effector domain targeting pericentromeric satellite‐3 DNA. We further study early events of transcriptome alterations upon DNMT‐catalyzed cytosine methylation. Our study sets a basis to dissect the order and kinetics of diverse chromatin‐associated events triggered by normal and aberrant DNA methylation.
Ce=O Terminated CeO2
Authors: Grinter David C. , Allan Michael , Yang Hyun Jin , Salcedo Agustín , Murgida Gustavo E. , Shaw Bobbie‐Jean , Pang Chi L. , Idriss Hicham , Ganduglia‐Pirovano M. Verónica , Thornton Geoff 
Published: April 2021

AbstractMultiply bonded lanthanide oxo groups are rare in coordination compounds and have not previously been reported for a surface termination of a lanthanide oxide. Here we report the observation of a Ce=O terminated ceria surface in a CeO2(111)‐(
×
)R30° reconstruction of ≈3 nm thick ceria islands prepared on Pt(111). This is evidenced by scanning tunnelling microscopy (STM), low energy electron diffraction (LEED) and high‐resolution electron energy loss spectroscopy (HREELS) measurements in conjunction with density functional theory (DFT) calculations. A Ce=O stretching frequency of 775 cm−1 is observed in HREELS, compared with 766 cm−1 calculated by DFT. The calculations also predict that the Ce=O bond is weak, with an oxygen vacancy formation energy of 0.85 eV. This could play an important role in the facile removal of lattice oxygen from CeO2, accompanied by the reduction of CeIV to CeIII, which is a key attribute of ceria‐based systems in connection with their unique catalytic properties.
Asymmetric Catalytic Vinylogous Addition Reactions Initiated by Meinwald Rearrangement of Vinyl Epoxides
Authors: Xu Jinxiu , Song Yanji , He Jun , Dong Shunxi , Lin Lili , Feng Xiaoming 
Published: April 2021

AbstractThe first catalytic asymmetric multiple vinylogous addition reactions initiated by Meinwald rearrangement of vinyl epoxides were realized by employing chiral N,N′‐dioxide/ScIII complex catalysts. The vinyl epoxides, as masked β,γ‐unsaturated aldehydes, via direct vinylogous additions with isatins, 2‐alkenoylpyridines or methyleneindolinones, provided a facile and efficient way for the synthesis of chiral 3‐hydroxy‐3‐substituted oxindoles, α,β‐unsaturated aldehydes and spiro‐cyclohexene indolinones, respectively with high efficiency and stereoselectivity. The control experiments and kinetic studies revealed that the Lewis acid acted as dual‐tasking catalyst, controlling the initial rearrangement to match subsequent enantioselective vinylogous addition reactions. A catalytic cycle with a possible transition model was proposed to illustrate the reaction mechanism.
Library Creation of Ultrasmall Multi‐metallic Nanoparticles Confined in Mesoporous MFI Zeolites
Authors: Jia Xiaoli , Jiang Jingang , Zou Shihui , Han Lu , Zhu Haiyin , Zhang Qing , Ma Yue , Luo Peng , Wu Peng , Mayoral Alvaro , Han Xinbao , Cheng Jun , Che Shunai 
Published: April 2021

AbstractThe development of materials integrated with ultrasmall multi‐metal nanoparticles (UMMNs) and mesoporous zeolite is a considerable challenge in chemistry and materials science. We designed a trifunctional surfactant, in which the pyridyl benzimidazole in the hydrophobic tail generates the mesopores through π–π stacking; the diquaternary ammonium in the hydrophilic headgroup direct the formation of MFI zeolite sheets and the nitrogen atoms in the heterocyclic rings coordinate with various metal ions to form UMMNs confined in the zeolite matrix after calcination and reduction. A library of 56 UMMNs confined within both micropores and mesopores of MFI zeolites (MMZs) with 4 mono‐, 14 bi‐ and 38 tri‐metallic nanoparticles (sizes of 1.3–4.7 nm) of combinations of Rh, Pd, Pt, Au, Fe, Co, Ni, Cu and Zn were made. An improved catalytic performance was exhibited in the sequence of Rh‐MMZ<Rh/Pt‐MMZ<Rh/Pt/Ni‐MMZ for the mild oxidation of methane to methanol or liquid acid.
Silicon Tetrakis(trifluoromethanesulfonate): A Simple Neutral Silane Acting as a Soft and Hard Lewis Superacid
Authors: Hermannsdorfer André , Driess Matthias 
Published: April 2021

AbstractA facile synthesis and isolation of pristine silicon tetrakis(trifluoromethanesulfonate), Si(OTf)4, is reported, acting as the first neutral silicon‐based Lewis superacid suitable towards soft and hard Lewis bases. Its OTf groups have a dual function: they are excellent leaving groups and modulate the degree of reactivity towards soft and hard Lewis bases. Exposed to soft Lewis donors, Si(OTf)4 leads to [L2Si(OTf)4] complexes (L=isocyanide, thioether and carbonyl compounds) with retention of all Si−OTf bonds. In contrast, it can cleave C−X bonds (X=F, Cl) of hard organic Lewis bases with a high tendency to form SiX4 (X=F, Cl) after halide/triflate exchange. Most notable, Si(OTf)4 allows a gentle oxydefluorination of mono‐ and bis(trifluoromethyl)benzenes, resulting in the formation of the corresponding benzoylium species, which are stabilized by the weakly coordinating [Si(OTf)6] dianion.
Experimental and kinetic studies on ash fusion behavior: a high‐precision acquisition method for ash fusion temperatures
Authors: Lv Yuan , Niu Yanqing , Wang Guangyao , Xu Liang , Lei Yu , Hui Shi'en , Wang Denghui 
Published: April 2021

AbstractAsh fusion characteristics including ash properties and morphological changes in high‐temperature fusion test were studied among four types of fuels comprising two woody biomass, three straw biomass, two bituminous coals, and three biomass/coal mixtures. On the basis of ash fusion behavior and kinetic analysis of the ash melting process, a high‐precision acquisition method for ash fusion temperatures (AFTs) was developed. First, a reading index of AFTs was proposed; that is, in high‐temperature fusion test, initial deformation temperature (IDT), softening temperature (ST), and fluid temperature (FT) could be identified by the height shrinkage of 38%, 86%, and 98%, or the area shrinkage of 50%, 77%, and 97%, respectively. Kinetic analysis conducted on height/area shrinkage indicated that activation energy was highly related to temperature difference among IDT, ST, and FT, and low activation energy facilitated the enlargement of the temperature differences of ST‐IDT and FT‐ST. XRD patterns illustrated low activation energy had a promotion effect on the generation of higher melting substances such as KAlSi3O8 and CaSiO3, causing the elevation of the ST and FT. At last, a calculation method for AFTs based on activation energy and average height/area shrinkage was performed, which had high repeatability within an average error of ~6°C.
Filter life comparison of different levels of nanofiber coated cleanable‐surface filter for gas turbine
Authors: Akduman Cigdem , Demirel Volkan , Tezcan Fatma 
Published: April 2021

AbstractHigh‐efficiency air filtration is a basic requirement for the most cost‐effective operation of high‐efficiency gas turbines. The filtration system protects the gas turbine from damaging debris. In gas turbine/dust collector applications, higher efficiency filtration could be achieved with nanofibers, which provide higher equipment protection than traditional media. With a nanofiber performance filter layer, the dust accumulates on the surface of the filtration media rather than within the media and could be cleaned off easily with a back pulse resulting in long filter life and a low‐operating pressure drop. In this study five type of gas tribune nanofiber coated corrugated cellulose/synthetic filter media were developed. Nanofiber coating was adjusted for five filtration efficiency level, 50 ≤ E < 60, 60 ≤ E < 70, 70 ≤ E < 85, 85 ≤ E < 95 and 95 ≤ E, pore size and filter‐life of the developed media were evaluated. One of the developed nanofiber coated media was also compared with two other commercial nanofiber coated gas tribune filter media, a glass fiber type filter media and a commercial fine fiber gas tribune filter media. It was seen that, with decreasing penetration levels due to nanofiber coating level, initial 30 cycle durations of filter life evaluation could reach about 229.9 to 250.7 min. Highest final cycle duration of 188.7 min belonged to cellulose/synthetic blend corrugated filter media with penetration of 13.66%. Nanofiber based surface filter media was cleaned up better than fine fiber media and final 30 cycle sequences were significantly higher. Surface of the nanofiber coated media was smoother when compared to fine fiber media and during the initial and final cycle test dust could not penetrate inside and could not hang to this smooth surface. So, with back pulse cleaning cake releasing have performed easily. It was also seen that, for higher filter life nanofiber coating should be uniform and robust to back pulse cleaning.
Synthesis and biological evaluation of new 4‐oxo‐thiazolidin‐2‐ylidene derivatives as antimicrobial agents
Authors: Chaban Taras , Matiichuk Yulia , Chulovska Zoriana , Tymoshuk Oleksandr , Chaban Ihor , Matiychuk Vasyl 
Published: April 2021

AbstractIn this study, an efficient synthesis and the antimicrobial activity evaluation of some 4‐oxo‐thiazolidin‐2‐ylidene derivatives are presented. The structures of the target substances were confirmed by using 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry, infrared spectroscopy, and elemental analysis. The synthesized compounds were evaluated for antimicrobial activity against five bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus) and two fungal strains (Candida albicans and Cryptococcus neoformans). It was shown that the compounds in this series possess antibacterial and antifungal activities.
Full coverage of a reader's interests in context‐based information filtering
Authors: Dumitrescu Alexandra , Santini Simone 
Published: April 2021

AbstractWe present a collection of algorithms to filter a stream of documents in such a way that the filtered documents will cover as well as possible the interest of a person, keeping in mind that, at any given time, the offered documents should not only be relevant, but should also be diversified, in the sense of covering all the interests of the person. We use a modification of the WEBSOM algorithm to create a user model based on a self‐organizing network trained using a collection of documents representative of the person's interests. We introduce the concepts offreshnessandcoverage. A document is fresh if it belongs to a semantic area of interest to a person for which no documents were seen in the recent past; a group of documents hascoverageto the extent to which it is a good representation of all the interests of a person. Our tests show that these algorithms can effectively increase the coverage of the documents that are shown to the user without overly affecting precision.
Kombinationsbewehrte Fundamentplatten im Geschosswohnungsbau
Authors: Haus Andreas 
Published: April 2021

AbstractIm Zuge der Innenstadtverdichtung und der damit einhergehenden Parkplatzproblematik werden neue Geschossbauten immer häufiger auch mit Tiefgaragen in mehreren Ebenen ausgeführt. Derartige Fundamentplatten werden aufgrund hoher Lasten, aber vor allem auch aufgrund der erforderlichen Rissbreitenbeschränkung, oftmals hoch bewehrt. Neben der umfangreichen Baustellenlogistik, die ein solch hoher Bewehrungsgrad mit sich bringt, zeigt sich häufig, dass vor allem die Bereiche mit einer hohen Bewehrungskonzentration fehleranfällig sind. Durch den Einsatz von Stahlfaserbeton gemäß der DAfStb‐Richtlinie „Stahlfaserbeton” lässt sich die Wirkung der Stahlfasern sowohl im Grenzzustand der Tragfähigkeit als auch im Grenzzustand der Gebrauchstauglichkeit anwenden.
Leistungsfähige Spezialbetone für Industrieböden
Authors: Kuhfeldt Sven 
Published: April 2021

AbstractDie Veränderlichkeit der Ausgangsstoffe verlangt, zusammen mit den zunehmend höheren Anforderungen an den Baustoff Beton selbst, eine ständige Weiterentwicklung der bestehenden Rezepturen. Das BV „Akasol” in Darmstadt spiegelt den Bedarf nach anspruchsvollen Betonen wider, die neben ihren normativen Eigenschaften auch noch ausführungsrelevante Anforderungen zu erfüllen haben. Durch den Einsatz von Dyckerhoff FERRODUR und VELODUR konnten nicht nur die Prozesse der Bauausführung wirtschaftlicher und ökonomischer gestaltet werden, sondern auch die Belastungen für Umwelt und Anwohner wirksam reduziert werden.
Multiple operant discrimination training to increase the precision of stimulus deltas following treatment of challenging behavior
Authors: Lambert Joseph M. , Lamers Mallory E. , Copeland Bailey A. , Banerjee Ipshita 
Published: April 2021

AbstractExplicit instruction on how to maximize reinforcement in volatile reinforcement conditions could decrease the probability of persistent but ineffective requesting while also maintaining low rates of challenging behavior. We used a multiple probe design to demonstrate a functional relation between multiple‐operant discrimination training and manding for available reinforces from a child with autism spectrum disorder and complex communication needs who used a low‐tech augmentative and alternative communication system. Despite a history of severe challenging behavior, rates of challenging behavior remained low throughout this study.
Paving the road toward eco‐effectiveness: Exploring the link between greenhouse gas emissions and firm performance
Authors: Russo Angeloantonio , Pogutz Stefano , Misani Nicola 
Published: April 2021

AbstractClimate change has increasingly attracted business attention over the last decade, focusing particularly on the eco‐efficiency debate. The goal of this paper is twofold. First, we contribute to the ongoing debate on the effects of environmental strategies on firm performance. We investigate this relationship by considering the relative greenhouse gas emissions (GHG) as a predictor of the eco‐efficiency of firms' environmental strategies. GHG emissions are a direct indicator of the environmental performance and effectively measure the firm's efforts in mitigating the impacts related to its processes and products. Second, we investigate the drivers that lead to an increase in the firm's environmental impact under the conditions of increasing market performance by the firm, therefore paving the road to the concept of eco‐effectiveness of corporate environmental strategies. To test our hypotheses, we use a sample of worldwide listed companies derived from the S&P 1200 list. A longitudinal analysis is run through generalized least squares regression models over the period 2004–2016. Results offer evidence of the direct relationship between the level of absolute emissions and market performance of the firm. Therefore, the findings have significant implications on the way we conceptualize corporate environmental sustainability and environmental strategies, shedding new light on the relation between environmental pressures and corporate growth.