bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium Catalyzed Controllable Mono‐ or Di‐Allylic Substitution Reaction of Benzothiazolylacetate with Allylic Alcohols
Authors: Yan Peipei , Pan Shulei , Hu Jinjin , Lu Limei , Zeng Xiaofei , Zhong Guofu 
Published: December 2018

AbstractA Pd(PPh3)4/acid catalyzed highly efficient and mono‐ or di‐selective allylic substitution reaction of benzothiazolylacetate and allylic alcohols has been developed. The mono‐ and di‐selectivities could be efficiently controlled by changing the reaction solvent and temperature, affording various mono‐ and di‐allylated products in good to excellent yields and selectivities. Both linear and branched allylic alcohols as well as allyl alcohol could all be well tolerated in the reaction.magnified image
The Impact of Video Laryngoscopy on the Clinical Learning Environment of Emergency Medicine Residents: A Report of 14,313 Intubations
Authors: Monette Derek L. , Brown Calvin A. , Benoit Justin L. , McMullan Jason T. , Carleton Steven C. , Steuerwald Michael T. , Eyre Andrew , Pallin Daniel J. ,   the NEAR III Investigators
Published: December 2018

AbstractBackgroundThe introduction of video laryngoscopy (VL) may impact emergency medicine (EM) residents' intubation practices.MethodsWe analyzed 14,313 intubations from 11 EM training sites, July 1, 2002, to December 31, 2012, assessing the likelihood of first‐attempt success and likelihood of having a second attempt, by rank and device. We determined whether direct laryngoscopy (DL) first‐attempt success decreased as VL became more prevalent using a logistic regression model with proportion of encounters initiated with VL at that center in the prior 90 and 365 days as predictors of DL first‐attempt success.ResultsFirst‐attempt success by PGY‐1s was 71% (95% confidence interval [CI] = 63% to 78%); PGY‐2s, 82% (95% CI = 78% to 86%); and PGY‐3+, 89% (95% CI = 85% to 92%). Residents' first‐attempt success rate was higher with the C‐MAC video laryngoscope (C‐MAC) versus DL, 92% versus 84% (risk difference [RD] = 8%, 95% CI = 4% to 11%), but there was no statistical difference between the GlideScope video laryngoscope (GVL) and DL, 80% versus 84% (RD = −4%, 95% CI = −10% to 1%). PGY‐1s were more likely to have a second intubation attempt after first‐attempt failure with VL versus DL: 32% versus 18% (RD = 14%, 95% CI = 5% to 23%). DL first‐attempt success rates did not decrease as VL became more prevalent.ConclusionsFirst‐attempt success increases with training. Interns are more likely to have a second attempt when using VL. The C‐MAC may be associated with increased first‐attempt success for EM residents compared with DL or GVL. The increasing prevalence of VL is not accompanied by a decrease in DL success.
Pneumococcal vaccination for welders: Global deployment within a multi‐national corporation
Authors: Donoghue A. Michael , Wesdock James C. 
Published: December 2018

BackgroundLobar pneumonia is an occupational disease of welders. This is the first report of global deployment of a pneumococcal vaccination program for welders within a multi‐national corporation.MethodsGlobal webinars were conducted to introduce the program. Communication packages translated into all location languages were deployed. All employee welders who had not previously been vaccinated were offered a free single dose of pneumococcal polysaccharide vaccine (PPV23) by on‐site location medical centers during normal working hours. Numbers of vaccinated welders were reported by each location each month.ResultsTwelve months after starting the program, 241 of 767 welders have been vaccinated (31%) across six countries.ConclusionsGlobal deployment of pneumococcal vaccination for welders can be successfully undertaken by a multi‐national corporation. Adoption of this practice by corporations could reduce the incidence and mortality of pneumonia among welders globally.
Active Edge‐Site‐Rich Carbon Nanocatalysts with Enhanced Electron Transfer for Efficient Electrochemical Hydrogen Peroxide Production
Authors: Sa Young Jin , Kim Jae Hyung , Joo Sang Hoon 
Published: December 2018

AbstractA highly efficient, metal‐free carbon nanocatalyst is presented that possesses abundant active, oxygenated graphitic edge sites. The edge site‐rich nanocarbon catalyst exhibits about 28 times higher activity for H2O2 production than a basal plane‐rich carbon nanotube with a H2O2 selectivity over 90 %. The oxidative treatment further promotes the H2O2 generation activity to reach close to the thermodynamic limit. The optimized nanocarbon catalyst shows a very high H2O2 production activity, surpassing previously reported catalysts in alkaline media. Moreover, it can stably produce H2O2 for 16 h with Faradaic efficiency reaching 99 % and accumulated H2O2 concentration of 24±2 mm. Importantly, we find that the heterogeneous electron transfer kinetics of the carbon‐based catalyst is closely related to the electrocatalytic activity, suggesting that first outer‐sphere electron transfer to O2 is an important step governing the H2O2 production rate.
Spontaneous Symmetry Breaking in the Formation of Supramolecular Polymers: Implications for the Origin of Biological Homochirality
Authors: Karunakaran Suneesh C. , Cafferty Brian J. , Weigert‐Muñoz Angela , Schuster Gary B. , Hud Nicholas V. 
Published: December 2018

AbstractAqueous solutions of the achiral, monomeric, nucleobase mimics (2,4,6‐triaminopyrimidine, TAP, and a cyanuric acid derivative, CyCo6) spontaneously assemble into macroscopic homochiral domains of supramolecular polymers. These assemblies exhibit a high degree of chiral amplification. Addition of a small quantity of one handedness of a chiral derivative of CyCo6 generates exclusively homochiral structures. This system exhibits the highest reported degree of chiral amplification for dynamic helical polymers or supramolecular helices. Significantly, homochiral polymers comprised of hexameric rosettes with structural features that resemble nucleic acids are formed from mixtures of cyanuric acid (Cy) and ribonucleotides (l‐, d‐pTARC) that arise spontaneously from the reaction of TAP with the sugars. These findings support the hypothesis that nucleic acid homochirality was a result of symmetry breaking at the supramolecular polymer level.
Siliziumtris(perchloro)dioxolen: ein neutrales Triplett‐Diradikal
Authors: Maskey Rezisha , Wadepohl Hubert , Greb Lutz 
Published: December 2018

AbstractDie Umsetzung von ortho‐Chinonen mit Siliciumtetraiodid führt zu neutralen Siliziumtrisdioxolenen in hoher Ausbeute, wodurch die noch unbekannte oxidierte Form von Triscatecholatosilikat‐Dianionen und das erste Beispiele von offenschaligen Semichinolaten die über ein einziges Nichtmetallzentrum verbrückt sind, zugängig werden. Siliziumtris(perchloro)dioxolen ist ein stabiles Diradikal mit einem Triplett‐Grundzustand, der durch Röntgen‐Kristallstrukturanalyse, IR‐, Resonanzraman‐, UV/VIS‐, (VT)EPR‐Spektroskopie und Kohn‐Sham‐Broken‐Symmetry‐Rechnungen gestützt wird. Vorläufige Ergebnisse legen nahe, dass der bevorzugte magnetische Zustand durch Wahl der Substituenten verändert werden kann.
Palladium‐Catalyzed Intermolecular [4+1] Spiroannulation by C(sp3)−H Activation and Naphthol Dearomatization
Authors: Tan Bojun , Bai Lu , Ding Pin , Liu Jingjing , Wang Yaoyu , Luan Xinjun 
Published: December 2018

AbstractA novel palladium‐catalyzed [4+1] spiroannulation was developed by using a C(sp3)−H activation/naphthol dearomatization approach. This bimolecular domino reaction of two aryl halides was realized through a sequence of cyclometallation‐facilitated C(sp3)−H activation, biaryl cross‐coupling, and naphthol dearomatization, thus rendering the rapid assembly of a new class of spirocyclic molecules in good yields with broad functional‐group tolerance. Preliminary mechanistic studies indicate that C−H cleavage is likely involved in the rate‐determining step, and a five‐membered palladacycle was identified as the key intermediate for the intermolecular coupling.
Towards the 150th Anniversary of the Markovnikov Rule
Authors: Beletskaya Irina P. , Nenajdenko Valentine G. 
Published: December 2018

AbstractThe Markovnikov rule, known to every student of organic chemistry, was formulated 150 years ago, in 1869. During its long history (almost as long as the history of organic chemistry itself), attitudes towards this famous statement of chemical reactivity have evolved from indifference up to the 1930s, through common acceptance as a useful educational paradigm with marginal use in research up to the 1990s, to its vigorous relaunch as an important designation of regioselectivity in the last few decades. The unexpected new popularity of the classical rule is accounted for by the rapid expansion in catalytic addition reactions and their critical importance as highly effective atom‐economical, regioselective methods in modern organic synthesis. A historical outline of the life and achievements of Vladimir Markovnikov is included to reveal the very wide scope of his interests as well as his prophetic predictions on structure, reactivity, selectivity, stereochemistry, and other key issues of organic chemistry.
Silicon Tris(perchloro)dioxolene: A Neutral Triplet Diradical
Authors: Maskey Rezisha , Wadepohl Hubert , Greb Lutz 
Published: December 2018

AbstractThe reaction of ortho‐quinones with silicon tetraiodide leads to neutral silicon trisdioxolenes in high yield, delivering the unknown oxidized form of triscatecholatosilicate dianions and the first example of open‐shell semiquinonates connected via a single non‐metal center. Silicon tris(perchloro)dioxolene is a stable diradical with a triplet ground state, as supported by X‐ray diffraction; IR, resonance Raman, UV/Vis, and (VT)EPR spectroscopy; and Kohn–Sham broken‐symmetry computations. Preliminary results suggest that the preferred magnetic ground state can be altered through variation of the substituents.
Green synthesis of Cu/zirconium silicate nanocomposite by using Rubia tinctorum leaf extract and its application in the preparation of N‐benzyl‐N‐arylcyanamides
Authors: Nasrollahzadeh Mahmoud , Sajjadi Mohaddeseh , Sajadi S. Mohammad 
Published: December 2018

A simple and convenient protocol was established for the synthesis of the N‐benzyl‐N‐arylcyanamides through N‐benzylation of a wide variety of arylcyanamides using copper nanoparticles immobilized on natural zirconium silicate as a novel and green heterogeneous catalyst. In this study, we showed a novel, cost efficient, convenient and simple method for green synthesis of Cu/zirconium silicate nanocomposite by using Rubia tinctorum leaf extract as capping and reducing agent. The structure of the novel catalyst was successfully characterized using a number of micro/spectroscopic techniques such as XRD, FESEM, BET, EDS, TEM, FT‐IR and elemental mapping. TEM micrographs of obtaining biocatalyst revealed mostly spherical particles with an average diameter of about 15–25 nm on the surface of natural support. The prepared catalyst was used in the N‐benzylation of a variety of arylcyanamides with benzyl bromide and showed high activity and stability for the efficient synthesis of N‐benzylarylcyanamides in good yields. Remarkably, the catalyst can be easily recovered from the reaction medium and reused up to five runs without losing its catalytic activity.
Hydrogenation of lactose for the production of lactitol
Authors: Cheng Shouyun , Martínez‐Monteagudo Sergio I. 
Published: December 2018

AbstractBecause of its chemical structure, low‐cost production, and large‐scale production, lactose is a promising source for the production of sugar alcohols. Lactitol is the primary sugar alcohol derived from lactose through a set of chemical reactions known as catalytic hydrogenation. Reaction products are strongly dependent on the reaction conditions and catalyst type. The purpose of this review is to examine the production of lactitol through hydrogenation of lactose. Technological aspects of hydrogenation of lactose are examined, including primary and secondary reaction products, type of catalyst used, catalyst deactivation and regeneration, kinetic models, selectivity, and reaction mechanisms. Research in this area is not as advanced as enzymatic catalysis, and there are opportunities for further studies in the fields of reaction optimization and detailed characterization of products.
Computational fluid dynamics simulation of system hydrodynamics in a riser of stage circulating fluidized bed reactor
Authors: Phupanit Jakkrapong , Soanuch Chaiwat , Korkerd Krittin , Piumsomboon Pornpote , Chalermsinsuwan Benjapon 
Published: December 2018

AbstractThe riser of conventional and stage circulating fluidized bed reactors were simulated using computational fluid dynamics. The objective was to examine the design parameter effects using a 23 statistical experimental design method. The results showed that number of reactor stages had the highest effect on the standard deviation of the solid volume fraction (SVF), the average SVF, and standard deviation of gas temperature in a horizontal direction. In addition, the reactor wall temperature had the highest effect on the average holding time of catalysts. Increasing the number of reactor stages could reduce the back‐mixing and increase the system turbulence. The average vertical and horizontal solid particle velocities in the reactor stage region were higher than in the other regions. At the reactor stage region, peaks in the gas temperature were observed. The advantages of a stage reactor were confirmed to be applied in all the operating condition cases, independent of the solid particle mass flux.
Board‐like Fused‐Thiophene Liquid Crystals and their Benzene Analogs: Facile Synthesis, Self‐Assembly, p‐Type Semiconductivity, and Photoluminescence
Authors: Zhao Kai‐Chun , Du Jun‐Qi , Wang Hai‐Feng , Zhao Ke‐Qing , Hu Ping , Wang Bi‐Qin , Monobe Hirosato , Heinrich Benoît , Donnio Bertrand 
Published: December 2018

AbstractFused‐thiophene discotic liquid crystals were designed and easily synthesized by Suzuki coupling and FeCl3 oxidized tandem cyclodehydrogenation reactions, including homo‐ and cross‐coupling reactions. The resulting hexagonal and rectangular columnar mesomorphic supramolecular structures formed were characterized by polarizing optical microscopy, differential scanning calorimetry, and small‐angle X‐ray scattering. The charge carrier transport properties in the mesophases of two of the synthesized fused‐thiophene discogens were measured by transient photocurrent time‐of‐flight (TOF) technique, revealing fast hole transport values in the range of 10−3 to 10−2 cm2 V−1 s−1, thus demonstrating potential applications in electronic devices. The luminescent sanidic mesogens, with different extended π‐conjugated systems, also emit blue, green, or red light, with absolute photoluminescent quantum yields as high as 18 %.
Dom zu Erfurt St. Marien – Instandsetzung und Ertüchtigung der Kavaten
Authors: Vockrodt Hans‐Jörg 
Published: December 2018

AbstractEng mit der Stadt Erfurt und ihrer Geschichte verbunden haben die Baumeister des Mittelalters mit den Stiftskirchen St. Marien und St. Severi zwei Gotteshäuser auf dem Domberg geschaffen, die weit über die Grenzen Thüringens ein beeindruckendes Zeugnis gotischer Kirchenbaukunst geben. Die Besonderheit hier der Domhügel „mons Sancti Severi – Berg des heiligen Severus“, welcher nach Osten hin steil abfällt und durch großartige mehrgeschossige gewölbte Substruktionen, die Kavaten, umbaut ist. Dieser Beitrag beschreibt neben der beeindruckenden Baugeschichte aktuelle Instandsetzungsmaßnahmen zum Erhalt der Kavaten. Nach einer Analyse des Bauwerkszustands und Formulierung der Instandsetzungsziele werden die gesteinsrestauratorische Instandsetzung und die Erneuerung des Oberbaus erläutert. Abschließend wird auf die im Rahmen der Baumaßnahme durchgeführte experimentelle Tragfähigkeitsbewertung eingegangen.
Multihalle Mannheim
Authors: Wenzel Fritz 
Published: December 2018

AbstractDie zur Bundesgartenschau 1975 im Mannheimer Herzogenriedpark errichtete Multihalle mit ihrer leicht und weit spannenden Gitterschale, einem Werk des 2015 verstorbenen Architekten Frei Otto, ist in die Jahre gekommen. Ihre außergewöhnliche, aus Holzlatten gefertigte Konstruktion erfährt weltweit Bewunderung. Seit 1998 ist die Multihalle eingetragenes Baudenkmal. Im Jahre 2011 musste sie, zunehmender Schäden wegen, für Veranstaltungen gesperrt werden. Seitdem gibt es unterschiedliche Vorstellungen und Vorschläge, was mit dem Bauwerk geschehen kann. Nachstehend werden das Entstehen und der derzeitige Zustand der Holzgitterschale beschrieben und die Möglichkeiten und Grenzen bautechnisch und denkmalpflegerisch angemessener Reparatur aufgezeigt.
LC–ESI–MS/MS determination of copanlisib, a novel PI3K inhibitor, in mouse plasma and its application to a pharmacokinetic study in mice
Authors: Dittakavi Sreekanth , Mullangi Ramesh 
Published: December 2018

AbstractA sensitive, selective and rapid LC–ESI–MS/MS method has been developed and validated for the quantification of copanlisib in mouse plasma using enasidenib as an internal standard (IS) as per regulatory guideline. Copanlisib and the IS were extracted from mouse plasma using ethyl acetate as an extraction solvent and chromatographed using an isocratic mobile phase (0.2% formic acid–acetonitrile; 25:75, v/v) on a HyPURITY C18column. Copanlisib and the IS eluted at ~0.95 and 2.00 min, respectively. The MS/MS ion transitions monitored werem/z481.1 → 360.1 andm/z474.0 → 456.0 for copanlisib and the IS, respectively. The calibration range was 3.59–3588 ng/mL. The intra‐ and inter‐batch accuracy and precision (RE and RSD) across quality controls met the acceptance criteria. Stability studies showed that copanlisib was stable in mouse plasma for one month. This novel method has been applied to a pharmacokinetic study in mice.
Matrix Coordination Induced Emission in a Three‐Dimensional Silver Cluster‐Assembled Material
Authors: Wei Zhong , Wu Xiao‐Hui , Luo Peng , Wang Jia‐Yin , Li Kai , Zang Shuang‐Quan 
Published: December 2018

AbstractDeveloping highly luminescent and extensively stable silver cluster‐assembled materials (SCAMs) from the inferior luminogens and unstable silver cluster is an important and challenging issue. Herein, a new luminescent three‐dimensional SCAM (Ag12CPPP, [Ag12(StBu)6(CF3COO)6(CPPP)2(DMAc)12]n; CPPP=2,5‐bis(4‐cyanophenyl)‐1,4‐bis(4‐(pyridine‐4‐yl)‐phenyl)‐1,4‐dihydropyrrolo[3,2‐b]pyrrole, DMAc=dimethylacetamide) was designed and synthesized with a quadridentate rigid emission ligand (CPPP) and a silver–chalcogenolate cluster (SCC) containing 12 AgI atoms. The luminescence study indicates that CPPP is an aggregation‐caused quenching (ACQ) molecule with twisted intramolecular charge transfer (TICT) character. Benefiting from the strong immobilization effect in the robust framework, the quantum yield of CPPP is greatly enhanced in Ag12CPPP compared with that of CPPP in solution or in the solid state. As a result, Ag12CPPP exhibits typical matrix coordination induced emission (MCIE) effect. Such efficient rigidifying methodology provides a promising approach for enhancing luminescence of ACQ molecules in an aggregated state and strengthening the silver cluster in an unstable state.
A Click‐Chemistry Linked 2′3′‐cGAMP Analogue
Authors: Dialer Clemens Reto , Stazzoni Samuele , Drexler David Jan , Müller Felix Moritz , Veth Simon , Pichler Alexander , Okamura Hidenori , Witte Gregor , Hopfner Karl‐Peter , Carell Thomas 
Published: December 2018

Abstract2′3′‐cGAMP is an uncanonical cyclic dinucleotide where one A and one G base are connected via a 3′‐5′ and a unique 2′‐5′ linkage. The molecule is produced by the cyclase cGAS in response to cytosolic DNA binding. cGAMP activates STING and hence one of the most powerful pathways of innate immunity. cGAMP analogues with uncharged linkages that feature better cellular penetrability are currently highly desired. Here, the synthesis of a cGAMP analogue with one amide and one triazole linkage is reported. The molecule is best prepared via a first CuI‐catalyzed click reaction, which establishes the triazole, while the cyclization is achieved by macrolactamization.
Topological and Steric Constraints to Stabilize Heteroleptic Copper(I) Complexes Combining Phenanthroline Ligands and Phosphines
Authors: Holler Michel , Delavaux‐Nicot Béatrice , Nierengarten Jean‐François 
Published: December 2018

AbstractHeteroleptic copper(I) complexes combining phenanthroline derivatives (NN) and chelating bisphosphine ligands (PP) are an important class of luminescent materials for various applications. Although thermodynamically stable, [Cu(NN)(PP)]+ derivatives are also kinetically unstable. As a result, a dynamic ligand‐exchange reaction is often observed in solution, leading to a dynamic mixture of heteroleptic and homoleptic complexes. To prevent the formation of the homoleptic species, macrocyclic phenanthroline ligands have been used for the preparation of [Cu(NN)(PP)]+ pseudorotaxanes. The topological constraint resulting from the macrocyclic structure of the NN ligand drives the thermodynamic equilibrium towards the exclusive formation of the heteroleptic complex as long as the macrocycle is large and flexible enough to allow for the threading of the PP ligand. Conversely, when the threading is prevented by steric constraints, unprecedented copper(I) complexes with a trigonal coordination geometry are obtained. These results are summarized in the present concept article.
Defektfreie Mixed‐Matrix‐Membranen aus Matrimid® und Aktivkohle für die Gastrennung
Authors: Georgopanos Prokopios , Weigelt Fynn , Shishatskiy Sergey , Filiz Volkan , Brinkmann Torsten , Abetz Volker 
Published: December 2018

AbstractIn dieser Arbeit wurden neue Mixed‐Matrix‐Membranen (MMM) aus Matrimid® und Aktivkohle (AK) für die Gasseparation untersucht. Das Ziel dieser Arbeit ist die Herstellung von Membranen mit im Vergleich zu reinen Matrimid®‐Membranen verbesserten Gaspermeationseigenschaften. Die Membranen wurden thermisch und morphologisch charakterisiert, außerdem wurden die Gastransporteigenschaften bestimmt. Bei steigendem AK‐Gehalt war die Selektivität für verschiedene Gaspaare konstant, die Permeabilitäten stiegen jedoch stark an.
Interactive Multi‐objective Dynamic Optimization of Bioreactors under Parametric Uncertainty
Authors: Nimmegeers Philippe , Vallerio Mattia , Telen Dries , Van Impe Jan , Logist Filip 
Published: December 2018

AbstractModel‐based optimization techniques play a key role in achieving a sustainable operation of biochemical processes. Models are an approximation of the real process under study, hence, uncertainty is inherently present and for a sustainable process operation this uncertainty should be accounted for. In practice, optimality with respect to different conflicting objectives is required and multi‐objective optimization is a valuable tool. In this article the sigma point approach is applied to account for parametric uncertainty in the frame of interactive multi‐objective bioprocess optimization.