bluuebunny/crossref_metadata_2025 huggingface dataset:
Effiziente lichtinduzierte pKa‐Modulation, gekoppelt mit basenkatalysierter Photochromie
Authors: Gurke Johannes , Budzák Šimon , Schmidt Bernd M. , Jacquemin Denis , Hecht Stefan
Published: March 2018

Photoschaltbare Säure‐Base‐Paare, die eine reversible Veränderung ihrer pKa‐Werte ermöglichen, sind für die Steuerung chemischer und biologischer Prozesse von großem Interesse. Eine signifikante, lichtinduzierte pKa‐Änderung dreier Einheiten in wässrigem Medium wurde zwischen zwei thermisch stabilen Zuständen realisiert, die sich mit UV‐ und grünem Licht ineinander umwandeln lassen. Die lichtinduzierte pKa‐Modulation beruht auf dem Einbau einer 3‐H‐Thiazol‐2‐on‐Einheit in das Gerüst eines Diarylethen‐Photoschalters, der bei photochemischem Ringschluss die heteroaromatische Stabilisierung der korrespondierenden, negativ geladenen Base verliert und somit deutlich weniger sauer wird. Zusätzlich wird die Effizienz der Photoreaktionen im deprotonierten Zustand drastisch erhöht, was zu einer katalytisch verstärkten Photochromie führt. Es scheint, dass die Protonierung einen signifikanten Einfluss auf die Form der Potentialenergiefläche von Grund‐ und angeregtem Zustand hat, wie durch quantenchemische Rechnungen gezeigt wird.
A Synchrotron‐Based Study of the Mary Rose Iron Cannonballs
Authors: Simon Hayley , Cibin Giannantonio , Robbins Phil , Day Sarah , Tang Chiu , Freestone Ian , Schofield Eleanor
Published: March 2018

Post‐excavation iron corrosion may be accelerated by the presence of Cl−, leading to conservation methods designed to remove Cl. This study exploits a unique opportunity to assess 35 years of conservation applied to cast‐iron cannon shot excavated from the Mary Rose. A combination of synchrotron X‐ray powder diffraction (SXPD), absorption spectroscopy (XAS), and fluorescence (XRF) mapping have been used to characterise the impact of conservation on the crystalline corrosion products, chlorine distribution, and speciation. The chlorinated phase akaganeite, β‐FeO(OH,Cl), was found on shot washed in corrosion inhibitor Hostacor IT with or without an additional reduction stage. No chlorinated phases were observed on the surface of shot stored in sodium sesquicarbonate (Na2CO3/NaHCO3); however, hibbingite, β‐Fe2(OH)3Cl, was present in metal pores. It is proposed that surface β‐FeO(OH,Cl) formed in the early stages of active conservation owing to oxidation of β‐Fe2(OH)3Cl at near‐neutral pH.
On the Origin of the Distinctly Different Reactivity of Ruthenium in [MO]+/CH4 Systems (M=Fe, Ru, Os)
Authors: Sun Xiaoyan , Zhou Shaodong , Yue Lei , Schlangen Maria , Schwarz Helmut
Published: March 2018

The thermal gas‐phase reactions of [RuO]+ with methane have been explored by FT‐ICR mass spectrometry and high‐level quantum‐chemical calculations. In contrast to the previously studied [FeO]+/CH4 and [OsO]+/CH4 couples, which undergo oxygen/hydrogen atom transfers and dehydrogenation, respectively, the [RuO]+/CH4 system produces selectively [Ru(CH)2]+ and H2O, albeit with much lower efficiency. Various mechanistic scenarios were uncovered, and the associated electronic origins were revealed by high‐level quantum‐chemical calculations. The reactivity differences observed for the [MO]+/CH4 couples (M=Fe, Ru, Os) are due to the subtle interplay of the spin–orbit coupling efficiency, orbital overlap, and relativistic effects.
Soft Robotics
Authors: Whitesides George M.
Published: March 2018

This description of “soft robotics” is not intended to be a conventional review, in the sense of a comprehensive technical summary of a developing field. Rather, its objective is to describe soft robotics as a new field—one that offers opportunities to chemists and materials scientists who like to make “things” and to work with macroscopic objects that move and exert force. It will give one (personal) view of what soft actuators and robots are, and how this class of soft devices fits into the more highly developed field of conventional “hard” robotics. It will also suggest how and why soft robotics is more than simply a minor technical “tweak” on hard robotics and propose a unique role for chemistry, and materials science, in this field. Soft robotics is, at its core, intellectually and technologically different from hard robotics, both because it has different objectives and uses and because it relies on the properties of materials to assume many of the roles played by sensors, actuators, and controllers in hard robotics.
Selective Polymerization Catalysis from Monomer Mixtures: Using a Commercial Cr‐Salen Catalyst To Access ABA Block Polyesters
Authors: Stößer Tim , Williams Charlotte K.
Published: March 2018

ABA triblock polyesters are synthesized using a commercially available chromium salen catalyst, in one pot, from monomer mixtures comprising epoxide, anhydride and lactone. The catalysis is highly selective and applies a single catalyst in two distinct pathways. It occurs first by epoxide/anhydride ring‐opening copolymerization and subsequently by lactone ring‐opening polymerization. It is used to produce various new ABA polyester polyols; these polyols can undergo post‐functionalization and chain‐extension reactions. The ability to use a commercial catalyst and switchable catalysis with monomer mixtures is expected to facilitate future explorations of new classes of block polymers.
Antimicrobial activity of tellurium‐loaded polymeric fiber meshes
Authors: Matharu Rupy Kaur , Charani Zhalan , Ciric Lena , Illangakoon Upulitha Eranka , Edirisinghe Mohan
Published: March 2018

A series of poly(methyl methacrylate) solutions loaded with varying concentrations of tellurium particles are prepared and processed into continuous and smooth microfiber meshes. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy are used to study the morphology and surface elemental composition of the composite fibers. Fiber diameters range between 7 and 14 µm with surface nanopores on the fibers ranging between 100 and 200 nm. Energy‐dispersive X‐ray spectroscopy confirmed successful incorporation of tellurium particles into the fibers. The concentration of tellurium in the composite significantly influenced fiber diameter, pore size, and morphology. The antibacterial activity of the prepared fibers is tested using Escherichia coli K12. The fibers are incubated in bacterial suspensions for 24 h at 37 °C and 150 rpm. Antibacterial activity is assessed through the colony‐counting method and is found to be dose dependent. The fibers with 4 wt % tellurium exhibited the most potent antibacterial properties as a 1.16 log reduction was observed. © 2018 The Authors. Journal of Applied Polymer Science Published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46368.
Adhesive based on micellar lupin protein isolate exhibiting oxygen barrier properties
Authors: Eibl Ina , von der Haar Daniela , Jesdinszki Marius , Stäbler Andreas , Schmid Markus , Langowski Horst‐Christian
Published: March 2018

In order to minimize the utilization of non‐renewable fossil resources, novel polymer sources for food packaging are being investigated. Micellar Lupin Protein (MLP), produced by dilution precipitation has great potential as functional laminating adhesive due to its high adhesion‐ and oxygen‐barrier properties. Formulations of MLP are used as laminating adhesive between high density‐polyethylene foil and paper as well as coating for poly(ethylene terephthalate) foil. The application of glycerol, sorbitol and combinations thereof as plasticizers are being investigated. Adhesive behavior as well as oxygen‐ and water vapor barrier properties were tested. The addition of both plasticizers enabled the preparation of processable coatings showing coherent and homogeneous morphology with improved adhesive behavior and oxygen barrier. When using sorbitol oxygen permeation coefficients of 0.93 cm3 (STP) 100 µm m−2 d−1 bar−1 were achieved. The laminates containing only sorbitol provided adhesion properties comparable to standard polyurethane laminates with cohesion failure in 100% of the by T‐Peel‐Test examined cases. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46383.
Modification of a fluorine–silicone acrylic resin with a free‐radical‐catching agent
Authors: Lei Huibin , He Deliang , Guo Yanni , Tang Yining , Lu Yao
Published: March 2018

Several kinds of free‐radical‐catching fluorine–silicone acrylic resins with different contents of 2,2,6,6‐tetramethyl‐4‐piperidyl methacrylate (TMPM) were synthesized by solution copolymerization. The chemical structures and properties of the resins were characterized and followed the performances of their respective coatings. The results demonstrate that these kinds of resins showed a high ability to produce nitroxide. The coatings had good thermal stability and hydrophobicity with water contact angles over 100°. Moreover, the weather resistance showed a great improvement for the synergetic protection by bonded TMPM, organic fluorine, and silicone. By aging tests, the modified coatings still maintained excellent mechanical properties with an impact strength and flexibility of 400 N cm and 2 mm, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46385.
Surface modification of carbon black to facilitate suspension polymerization of styrene and carbon black
Authors: Hou Yaya , Zhao Tianqi , Shi Yanpeng , Fan Jie , Zheng Ran , Zhang Yumin , Gu Qiang
Published: March 2018

To carry out suspension polymerization of styrene in the presence of carbon black, an effective method was introduced to modify carbon black using nitric acid for oxygen treatment. The surface modification of carbon black with oxidation was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy (SEM), which demonstrated that the chemical structure of carbon black has clearly changed. Compared with pristine carbon black (CB), SEM illustrates that the aggregation phenomenon of modified carbon black (MCB) was clearly weakened. After modification, the aggregation and inhibition effects of MCB on the polymerization of polystyrene/modified CB (PS/MCB) composite particles are obviously weakened. The lipophilicity of CB after modification was also increased during the synthesis of PS/MCB. The oxidized CB was successfully dispersed by polystyrene using in situ suspension polymerization. The dispersion and dosage of MCB in PS/MCB composite particles was greatly improved over that of CB in PS/CB composite particles. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46387.
Curing reaction mechanism and heat resistance properties of hexa‐(4‐carboxyl‐phenoxy)‐cyclotriphosphazene/bisphenol A aniline benzoxazine blends
Authors: He Jing , Li Xiangyu , Fu Yizheng , Zhu Huibin , Zhao Guizhe , Wang Zhi
Published: March 2018

A blend system of hexa‐(4‐carboxyl‐phenoxy)‐cyclotriphosphazene (HCPCP) and bisphenol A aniline benzoxazine (BA‐a) was prepared, and its curing reaction mechanism and heat resistance properties were studied. The curing reaction mechanism of the blend was explored by differential scanning calorimetry, Fourier transform infrared spectroscopy, and modeling software using model compounds Ar‐COOH and hexachlorocyclotriphosphazene (HCCP). The heat resistance properties of the cured blends were studied by thermogravimetric analysis and dynamic mechanical analysis. The polymerization of benzoxazine was catalyzed by HCPCP through phosphazene ring and acid groups, and phosphazene played a predominant role. Compared with the materials with a single functional group (Ar‐COOH and HCCP), HCPCP containing two functional groups (phosphazene ring and acid) exhibited weaker catalytic effects, mainly due to the high molecular weight of HCPCP obstructing movement and causing steric hindrance. In addition, HCPCP had a positive effect on the thermal stability of polybenzoxazine from 250 to 400 °C. When the HCPCP content reached 3%, the cured blend had the highest glass‐transition temperature (222.2 °C), which is higher by 20 °C than that of cured benzoxazine. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46389.
Systematische Nachrechnung des Brückenbestands in Mecklenburg‐Vorpommern
Authors: Steinbock Oliver , Mertzsch Olaf , Hampel Torsten , Schmidt Nico , Curbach Manfred
Published: March 2018

Die Bewertung von Bestandsbrücken rückte in Verbindung mit der Einführung der Nachrechnungsrichtlinie von Straßenbrücken im Jahr 2011 vermehrt auch in den Fokus der Forschung. Gegenüber Brückenneubauten ist hier eine differenzierte Betrachtungsweise notwendig, da Bestandsbrücken nach anderen Maßstäben entworfen und gebaut wurden. Um der anspruchsvollen Ingenieuraufgabe bei der Bewertung von Bestandsbrücken gerecht zu werden, sieht die Nachrechnungsrichtlinie ein stufenweises Vorgehen mit steigendem Detaillierungsgrad in der rechnerischen Nachweisführung vor. Die stetige Fortschreibung der Nachrechnungsrichtlinie, die u. a. erstmals im April 2015 ergänzt wurde, macht dabei den Input aus Praxis und Forschung notwendig. Das Vorhaben der Wissenschaftlich‐technischen Betreuung beim Projekt zur Anwendung der Nachrechnungsrichtlinie auf den Brückenbestand Mecklenburg‐Vorpommern (kurz: WTB) griff den Gedanken der Interaktion von Praxis und Forschung auf und erweiterte diesen um die systematische Bewertung des Brückenbestands in der Baulast des Landes Mecklenburg‐Vorpommern (M‐V). Nachfolgender Beitrag gibt einen Überblick über die Priorisierung eines für die neuen Bundesländer charakteristischen Brückenbestands und die systematische Nachrechnung in Zusammenarbeit von Behörden, Unternehmen und Forschungseinrichtung.
In vivo metabolite profiles of isoimperatorin and phellopterin in rats analyzed using HPLC coupled with diode array detector and electrospray ionization ion trap time‐of‐flight mass spectrometry technique
Authors: Li Lili , Chen Jiaxing , Yang Xiaoyan , Zhang Yingtao , Yang Donghui
Published: March 2018

Isoimperatorin (IP) and phellopterin (PP) are two furocoumarins existing in Angelicae Dahuricae Radix. There is an isopentenyloxyl substituted at C‐5 in IP, and an isopentenyloxyl and a methoxyl substituted at C‐8 and C‐5, respectively, in PP. To elucidate the in vivo metabolic characteristics of PP and IP, HPLC coupled with diode array detector and electrospray ionization ion trap time‐of‐flight mass spectrometry technique was used. In total, 111 metabolites, including 53 new ones, were identified from the urine and plasma samples of rats after oral administration of IP and PP, respectively. The metabolites were formed through eight reactions on IP and PP: oxidation, hydroxylation–hydrogenation, carboxylation on the isopentenyloxyl, O‐dealkylation, hydroxylation on the furocoumarin nucleus, ring‐opening reaction on the furan ring and reduction or ring‐opening reaction on the lactone ring. Among these, hydroxylation on the furocoumarin nucleus was found for the first time for in vivo metabolites of PP and IP, and the ring‐opening reaction on the furan ring or lactone ring was found for the first time for in vivo metabolites of isopentenyloxyl furocoumarins. The research gave us a new insight into the in vivo metabolic profiles of IP and PP, which could help us better understand their important roles as two active constituents of Angelicae Dahuricae Radix.
Detection of trace amounts of citrinin in dried orange peel by using an optimized extraction method coupled with ultra‐performance liquid chromatography–tandem mass spectrometry
Authors: Liu Yanqing , Wang Hongwu , Yao Su , Zhu Peijie
Published: March 2018

A fast and sensitive method involving ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was introduced to detect citrinin in dried orange peel. A series of extraction, purification and chromatographic conditions was also systematically examined. With the proposed method, the obtained calibration graph was linear, with an R of 0.9996 within a concentration range of 0.5–10 ng/mL. The estimated limits of detection and quantification were 0.05 and 0.17 ng/mL, respectively. Under the selected conditions, the relative recoveries in different citrus products spiked with 1–10 ng/mL citrinin were 89.4–98.7% with RSDs of <2.5%. Compared with previously reported analytical methods, the newly developed UPLC–MS/MS method showed excellent sensitivity and good precision in detecting citrinin. The results indicated that it is a reliable and effective technique for the detection of trace citrinin in dried orange peel.
Co‐creation for sustainable development: The bounds of NGO contributions to inclusive business
Authors: Nahi Tytti
Published: March 2018

The sustainable development agenda is placing increasing expectations on business and cross‐sector partnerships. One of the rising propositions is that companies and non‐governmental organizations (NGOs) can co‐create inclusive business ventures that are simultaneously both profitable and poverty reducing. A considerable number of studies have found that NGOs can bring valuable knowledge, capabilities, contacts, and legitimacy to these initiatives. This paper deepens the discussion from what NGOs can contribute to how and to what extent. Based on practice theory and a two‐and‐half‐year study of 7 inclusive business partnerships between companies and NGOs, this study finds that NGO representatives contribute to inclusive business initiatives by skillfully drawing on and adapting their potential resources and practices. However, this study identifies five factors that bound NGO contributions. Thereby, this paper advances a nuanced discussion of the potential and the limitations of partnerships as a means of combining poverty alleviation and profitability.
A novel CALM algorithm in student profiling
Authors: Jha Sunil Kr. , Shorko Stefan
Published: March 2018

Computational intelligence plays a significant role in the improvement of the learning process. Student profile provides an overview of personality and establishes a connection between the abilities and learning preferences. The objective of the present study is to develop an algorithmic approach to student profiling in the selection of subjects and profession. A calculative associative logical memorable (CALM) algorithm is proposed which integrates calculative thinking, association, logical perception, and memorizing features. The developed CALM approach is also validated by including the environmental and social constraints. The validation outcomes claim that the CALM is able to design a noble student profiling framework which leads to further improvement in the quality of the learning process.
A semantic approach to enhance moodle with personalization
Authors: Perišić Jasmina , Milovanović Marina , Kazi Zoltan
Published: March 2018

The purpose of this paper is to present a framework for an adaptive mechanism implemented in Moodle in order to improve learning outcomes and students' satisfaction with the learning process. The proposed mechanism adapts the learning content within the course according to students' characteristics expressed by their learning style. In our study, student's learning style is dynamically determined by monitoring students’ actions and activities during the learning process, and detecting patterns of behavior that correspond to specific learning style. Semantic web technologies are in the background of the entire adaptive system. In order to examine the effectiveness of the proposed model and students' feedback, an evaluation study was conducted on two groups of students. Students from the control group had access to standard Moodle course, while students from experimental group had access to personalized learning content. The results indicated that students' performance was improved by using the proposed framework, while the student's feedback from regarding its usefulness was positive.
The ULTIMATE Reagent: A Universal Photocleavable and Clickable Reagent for the Regiospecific and Reversible End Labeling of Any Nucleic Acid
Authors: Jain Piyush K. , Friedman Simon H.
Published: March 2018

There is a need for methods to chemically incorporate photocleavable labels into synthetic and biologically sourced nucleic acids in a chemically defined and reversible manner. We have previously demonstrated that the light‐cleaved diazo di‐methoxy nitro phenyl ethyl (diazo‐DMNPE) group has a remarkable regiospecificity for modifying terminally phosphorylated siRNA. Building on this observation, we have identified conditions under which a diazo‐DMNPE reagent that we designed (diazo‐DMNPE‐azide or DDA) is able to singly modify any nucleic acid (RNA, DNA, single‐stranded, double‐stranded, 3′ or 5′ phosphate). It can then be modified with any clickable reagent to incorporate arbitrary labels such as fluorophores into the nucleic acid. Finally, native nucleic acid can be regenerated directly through photolysis of the reagent. Use of the described approach should allow for the tagging of any nucleic acid, from any source—natural or unnatural—while allowing for the light‐induced regeneration of native nucleic acid.
An Unusual Fatty Acyl:Adenylate Ligase (FAAL)–Acyl Carrier Protein (ACP) Didomain in Ambruticin Biosynthesis
Authors: Hemmerling Franziska , Lebe Karen E. , Wunderlich Johannes , Hahn Frank
Published: March 2018

The divinylcyclopropane (DVC) fragment of the ambruticins is proposed to be formed by a unique polyene cyclisation mechanism, in which the unusual didomain AmbG plays a key role. It is proposed to activate the branched thioester carboxylic acid resulting from polyene cyclisation and to transfer it to its associated acyl carrier protein (ACP). After oxidative decarboxylation, the intermediate is channelled back into polyketide synthase (PKS) processing. AmbG was previously annotated as an adenylation–thiolation didomain with a very unusual substrate selectivity code but has not yet been biochemically studied. On the basis of sequence and homology model analysis, we reannotate AmbG as a fatty acyl:adenylate ligase (FAAL)–acyl carrier protein didomain with unusual substrate specificity. The expected adenylate‐forming activity on fatty acids was confirmed by in vitro studies. AmbG also adenylates a number of structurally diverse carboxylic acids, including functionalised fatty acids and unsaturated and aromatic carboxylic acids. HPLC‐MS analysis and competition experiments show that AmbG preferentially acylates its ACP with long‐chain hydrophobic acids and tolerates a π system and a branch near the carboxylic acid. AmbG is the first characterised example of a FAAL–ACP didomain that is centrally located in a PKS and apparently activates a polyketidic intermediate. This is an important step towards deeper biosynthetic studies such as partial reconstitution of the ambruticin pathway to elucidate DVC formation.
Comparison of single versus dual antiplatelet therapy after TAVR: A systematic review and meta‐analysis
Authors: Raheja Hitesh , Garg Aakash , Goel Sunny , Banerjee Kinjal , Hollander Gerald , Shani Jacob , Mick Stephanie , White Jonathan , Krishnaswamy Amar , Kapadia Samir
Published: March 2018

Objective

We aim to evaluate the efficacy of dual versus single anti‐platelet therapy (SAPT) after TAVR through a systematic review and meta‐analysis of published research.

Background

Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is a commonly practiced strategy after transcatheter aortic valve replacement (TAVR). However, there is lack of sufficient evidence supporting this approach.

Method

We searched PubMed, EMBASE, the Cochrane Central Register of Controlled trials, and the clinical trial registry maintained at clinicaltrials.gov for randomized control trials (RCT) and observational studies comparing DAPT with SAPT post TAVR. Event rates were compared using a forest plot of relative risk with 95% confidence intervals using a random‐effects model assuming inter‐study heterogeneity.

Results

A total of six studies (3 RCTs and 3 observational studies, n = 840) were included in the final analysis. Compared to SAPT, DAPT was associated with increased risk of significant bleeding (life threatening and major) [RR = 2.52 (95% CI 1.62–3.92, P < 0.0001)] with the number needed to harm for major or life‐threatening bleeding calculated to be 10.4. There was no significant difference in the incidence of stroke [RR = 1.06 (95% CI, 0.43–2.60, P = 0.90)], spontaneous myocardial infarction [RR = 2.08 (95% CI, 0.56–7.70, P = 0.27)] and all‐cause mortality [RR = 1.18 (95% CI, 0.68–2.05, P = 0.56] in the DAPT and SAPT groups.

Conclusion

In this small meta‐analysis of DAPT versus SAPT after TAVR, DAPT did not prevent stroke, myocardial infarction or death while the risk of bleeding was higher. Results from ongoing trials are awaited to determine the best anti‐thrombotic approach after TAVR.
From Mesocates to Helicates: Structural, Magnetic and Chiro‐Optical Studies on Nickel(II) Supramolecular Assemblies Derived from Tetradentate Schiff Bases
Authors: Mayans Júlia , Font‐Bardia Mercè , Di Bari Lorenzo , Arrico Lorenzo , Zinna Francesco , Pescitelli Gennaro , Escuer Albert
Published: March 2018

The systematic reactions of a family of tetradentate pyridyl/imine and quinolyl/imine racemic or enantiopure Schiff bases with Ni(NO3)2 or Ni(ClO4)2 in the presence of sodium azide yielded, as a function of the starting racemic, chiral or achiral base, a set of chiral, meso or achiral complexes. In all cases, the compounds consist of two NiII cations linked by a double azido bridge in its end‐on coordination mode. All the dimers exhibit a mesocate supramolecular structure and one of them, the unprecedented mix of helicate and mesocate in 2:1 ratio. The transition from mesocate to helicate conformation has been reached by tuning the flexibility of the central spacers of the Schiff bases and the size of the substituents. Electronic circular dichroism (ECD) studies have been performed for two pairs of enantiomers and interpreted by means of DFT calculations. Susceptibility measurements show a ferromagnetic coupling between the NiII cations mediated by the end‐on azido bridges.
An Unprecedented Retro‐Mumm Rearrangement Revealed by ESI‐MS/MS, IRMPD Spectroscopy, and DFT Calculations
Authors: Iacobucci Claudio , Reale Samantha , Aschi Massimiliano , Oomens Jos , Berden Giel , De Angelis Francesco
Published: March 2018

Brønsted acids and protic solvents mediate acyl transfer, known as the Mumm rearrangement, from imidates to the corresponding acylamides. This represents a key step in several reactions, for example, the Ugi four‐component reaction (U‐4CR) and Passerini three‐component reaction (P‐3CR). Herein, an unprecedented break of the non‐reversibility of the Mumm rearrangement is reported. A combination of electrospray tandem mass spectrometry (ESI‐MS/MS), infrared multiphoton dissociation (IRMPD) ion spectroscopy and theoretical calculations demonstrates the occurrence of the retro‐Mumm rearrangement of protonated isopeptides in the gas phase. In the gas phase, the extra proton acquired during ESI promotes the backward isomerisation reaction in a catalytic fashion.
Solvent and Autocatalytic Effects on the Stabilisation of the σ‐Complex during Electrophilic Aromatic Chlorination
Authors: Van Lommel Ruben , Moors Samuel L. C. , De Proft Frank
Published: March 2018

The solvent and autocatalytic effects of the electrophilic aromatic chlorination of benzene are studied using a combined approach of static calculations and ab initio metadynamics simulations. Different possible reaction pathways are investigated and the influence of the solvents (CCl4, acetonitrile and acetic acid) is thoroughly assessed. Our results show that the stability and lifetime of a charged σ‐complex is increased by electrostatic stabilisation effects of the environment, which can originate from catalytic HCl, solvating effects of polar solvents (acetonitrile), or specific hydrogen bonding interactions with the solvent (acetic acid). Metadynamics simulations reveal a new chlorine addition mechanism explaining the autocatalytic effects of the reaction. The strength of combining static calculations and metadynamics simulations is highlighted, which provide complementary insight into chemical reactions in solvent.
Nickel‐Catalyzed Alkylarylation of Activated Alkenes with Benzyl‐amines via C−N Bond Activation
Authors: Yu Hui , Hu Bin , Huang Hanmin
Published: March 2018

A nickel‐catalyzed alkylarylation of active alkenes with tertiary benzylamines was achieved by charge‐transfer‐complex promoted C−N bond activation. The reaction proceeded through initial Ni‐catalyzed C−N bond activation, followed by sequential radical addition, redox and proton abstraction with cleaved amine moiety in the absence of oxidant, and provides an efficient method to prepare various alkyl‐substituted oxindoles and dihydroquinolinones in good yields.
Formal Lossen Rearrangement/[3+2] Annulation Cascade Catalyzed by a Modified Cyclopentadienyl RhIII Complex
Authors: Yamada Takayuki , Shibata Yu , Kawauchi Susumu , Yoshizaki Soichi , Tanaka Ken
Published: March 2018

It has been established that a cyclopentadienyl RhIII complex with two phenyl groups and a pendant amide moiety catalyzes the formal Lossen rearrangement/[3+2] annulation cascade of N‐pivaloyl benzamides and acrylamides with alkynes leading to substituted indoles and pyrroles. Mechanistic studies revealed that this cascade reaction proceeds via not the Lossen rearrangement to form anilides or enamides but C−H bond cleavage, alkyne insertion, and the formal Lossen rearrangement.
Numerical Simulation of Industrial Dry Flue‐Gas Desulfurization Processes
Authors: Klaka Tobias , Kaiser Sven , Barbe Stéphan
Published: March 2018

Rauchgase aus Kohlekraftwerken enthalten beträchtliche Mengen an Schwefeldioxid, die für die Umwelt dramatische Folgen haben können. Die richtige Auslegung von Entschwefelungsverfahren ist entscheidend und beruht überwiegend auf empirischen Ansätzen. Um die Belastbarkeit und die Zuverlässigkeit des Auslegungsverfahrens zu verbessern, wurde ein Rechenmodel für die trockene Entschwefelung von Rauchgasen mit Partikeln auf Calciumbasis entwickelt. Der detaillierte Aufbau wird beschrieben und die Berechnungsergebnisse mit Prozessdaten aus einem Steinkohlekraftwerk verglichen. Anschließend wurde exemplarisch eine Sensitivitätsanalyse durchgeführt.
Effusion‐based lymphoma with morphological regression but with clonal genetic features after aspiration
Authors: Tsai Meng‐Chen , Kuo Chun‐Chi , Su Ying‐Zhen , Hsieh Yen‐Chuan , Chuang Shih‐Sung
Published: March 2018

Effusion‐based lymphoma (EBL) is a rare but distinct entity of large B‐cell lymphoma in effusion without association with human herpes virus‐8 (HHV‐8). Spontaneous regression after pleurocentesis has been observed; but to our knowledge, there are no reports on the morphological and molecular features of subsequent aspirations in regressing cases. Here, we report the case of a 92‐year‐old male with chronic obstructive pulmonary disease, who presented with right pleural effusion. He had no human immunodeficiency virus, hepatitis B virus, or hepatitis C virus infection, and CT scans revealed no mass lesion. The first pleural effusion aspiration cytology revealed large lymphoma cells with vesicular nuclei, irregular nuclear contours, and prominent nucleoli, consistent with EBL. The second aspiration cytology showed a few slightly enlarged lymphocytes in a background of small lymphocytes. Immunohistochemical study on cell block of the second aspiration revealed equal amounts of CD3‐positive and CD20‐positive cells. All these cells on the section tested negative for HHV‐8 through immunohistochemistry and Epstein‐Barr virus by in situ hybridization. Our initial impression was EBL in regression. However, flow cytometric immunophenotyping showed monotypic light chain expression of the gated B‐cells. B‐cell receptor gene rearrangement study showed a clonal result. Furthermore, fluorescence in situ hybridization revealed rearrangement of IGH gene. The diagnosis of the second aspiration was EBL with morphological regression but retained clonal genetic features. The patient passed away one month after diagnosis without chemotherapy. This case illustrated the importance of ancillary studies in confirming the clonal nature of a morphologically regressing EBL.
Study on Pulse Compression Ultrasonic Imaging by a Stacked M‐Sequence Encoding Probe
Authors: Murata Yorinobu , Kaneda Daiyu
Published: March 2018

If an ultrasonic imaging inside an object is possible without scanning by using an ultrasonic probe having a small aperture, the ultrasonic imaging system becomes a simpler and easier system. We have developed a stacked encoding ultrasonic transducer which can transceive an M‐sequence signal only by a pulse drive in order to realize an ultrasonic measurement with a high resolution and high sensitivity. When an ultrasonic probe with such transducer is used, a pulse compression measurement is enabled only with a general ultrasonic flaw detector and a personal computer (PC) without using special devices. In this study, we focused on the characteristic that the received waveform by this probe changes with transceiver directions of a wave. A stacked M‐sequence encoding probe of 7 bits length was manufactured and the one‐dimensional point spread function in transceiver angle was obtained. As a result, it was confirmed that this probe has not only the pulse compression characteristic, but also the angle selecting characteristic. Finally, by using the proposed probe, the cross‐sectional imaging for point objects without scanning was demonstrated.
Reaction Rates of Various N‐Acylenamines in the Inverse‐Electron‐Demand Diels–Alder Reaction
Authors: Engelsma Sander B. , van den Ende Thomas C. , Overkleeft Hermen S. , van der Marel Gijsbert A. , Filippov Dmitri V.
Published: March 2018

In light of the bioorthogonal inverse‐electron‐demand Diels–Alder strategy, an extended investigation into the effects of ring strain and electron inductive effects on the reactivity of the N‐acylenamine core towards tetrazine has been carried out. Through a comparative study between N‐acylazetines, N‐vinylcarbamates and an N‐vinylamide it was shown that ring strain has a more significant effect on reaction rate than electron donation. A significantly improved synthetic route is reported for the preparation of an N‐acylazetine biorthogonal tag we have invented previously.
Ion Transfer Voltammetry in Polyurethane Thin Films Based on Functionalised Cationic [6]Helicenes for Carbonate Detection
Authors: Jarolímová Zdeňka , Bosson Johann , Labrador Geraldine M. , Lacour Jérôme , Bakker Eric
Published: March 2018

We explore here molecular ion‐to‐electron redox probes based on cationic diaza, azaoxa, and dioxa [6]helicenes and their derivatives as ion‐to‐electron transducers for the electrochemical detection of anions. These cationic [6]helicenes exhibit reversible and reproducible oxidation/reduction behavior and facilitate the anion transfer of Gaussian shape into polymeric thin layer sensing films. Films composed of bis(2‐ethylhexyl) sebacate (DOS), polyurethane (PU), tetrakis(4‐chlorophenyl)borate tetradodecylammonium salt (ETH 500) and [6]helicenes were interrogated by cyclic voltammetry. Even though the peak separation of 90 mV is larger than ideal, the observed peak width at half maximum of 130 mV and the linear relationship between current and scan rate are near theoretical values, confirming a surface confined process. A Nernstian shift of the peaks with increasing carbonate concentration is obtained in the presence of carbonate ionophore VII incorporated into the thin sensing film. The concentration of carbonate was determined in an unfiltered sample of the Arve river (flowing from Chamonix to Geneva) and compared to a reference method (automatic titrator with potentiometric detection). The results suggested that cationic diaza [6]helicene functionalized with two bromine atoms is an attractive molecular ion‐to‐electron transducer for anion‐selective electrodes.
Rapid and Flash Tests: Indicator for Quality of HT‐PEM Fuel Cells Batches?
Authors: Rastedt M. , Büsselmann J. , Tullius V. , Wagner P. , Dyck A.
Published: March 2018

In order to control the batch quality of membrane electrode assemblies (MEA), two new short tests have been developed. The first being a rapid test, composed of a start‐up and break‐in followed by initial characterization and has a test duration of about 65 h, while the second is a flash test, which is reduced by the break‐in, so that the maximum duration is 8 h. These tests have been compared with classical accelerated stress tests like load cycling at high current densities and start/stop‐cycling. For the investigations presented in this publication, high temperature polymer electrolyte MEAs from two different suppliers were used. The extensive electrochemical characterization clearly shows that the newly introduced fast tests can be used to check the batch qualities. In addition to the electrochemical investigations, the phosphoric acid content of all MEAs has been determined and ex situ micro‐computed tomography analysis has been performed.
Individual differences in decision making competence revealed by multivariate fMRI
Authors: Talukdar Tanveer , Román Francisco J. , Operskalski Joachim T. , Zwilling Christopher E. , Barbey Aron K.
Published: March 2018

While an extensive literature in decision neuroscience has elucidated the neurobiological foundations of decision making, prior research has focused primarily on group‐level effects in a sample population. Due to the presence of inherent differences between individuals’ cognitive abilities, it is also important to examine the neural correlates of decision making that explain interindividual variability in cognitive performance. This study therefore investigated how individual differences in decision making competence, as measured by the Adult Decision Making Competence (A‐DMC) battery, are related to functional brain connectivity patterns derived from resting‐state fMRI data in a sample of 304 healthy participants. We examined connectome‐wide associations, identifying regions within frontal, parietal, temporal, and occipital cortex that demonstrated significant associations with decision making competence. We then assessed whether the functional interactions between brain regions sensitive to decision making competence and seven intrinsic connectivity networks (ICNs) were predictive of specific facets of decision making assessed by subtests of the A‐DMC battery. Our findings suggest that individual differences in specific facets of decision making competence are mediated by ICNs that support executive, social, and perceptual processes, and motivate an integrative framework for understanding the neural basis of individual differences in decision making competence.
Methadone against cancer: Lost in translation
Authors: Theile Dirk , Mikus Gerd
Published: March 2018

Recently, the opioid analgesic d,l‐methadone has gained much attention as a potential antineoplastic compound, considerably triggered through lay press and media. In consequence, physicians and pharmacists are currently confronted with numerous patients willing to use d,l‐methadone against their malignancies. Well‐performed in vitro and in vivo models have in fact shown pro‐apoptotic effects of d,l‐methadone or other opioids, but also proliferation‐stimulating properties. Moreover, the mechanisms of proposed opioid‐stimulated apoptosis are incompletely described or contradicting. Finally, the receptors mostly responsible for induction of apoptosis by d,l‐methadone remain unclear as contributions of both µ‐opioid receptors, Fas cell death receptors, toll‐like receptors, N‐Methyl‐d‐aspartate receptors and opioid growth factor receptors were suggested. Such ambiguity prevents rational application of d,l‐methadone or patient stratification to enhance beneficial antineoplastic effects. From a clinical point of view, d,l‐methadone and other opioids might in fact prolong survival, but such effects likely originate from their analgesic and neuro‐psychotropic properties and, thus, improvements of quality of life. Crucial obstacles to the administration of d,l‐methadone are incomplete knowledge about its systemic disposition, highly variable pharmacokinetics, profound drug–drug‐ or drug–disease interaction and QT‐prolongation potential. This article summarizes and rates the pharmacological basis of d,l‐methadone as an antineoplastic agent and puts its administration in clinical oncology into perspective. Despite enthralling experimental findings about d,l‐methadone‐mediated apoptosis in cancerous cells or tissues, clinicians should realize the current lack of evidence for the use of d,l‐methadone as an antineoplastic agent. Its administration against cancer pain is, however, tenable, albeit restricted to certain clinical situations.
IFN‐γ‐mediated inhibition of lung cancer correlates with PD‐L1 expression and is regulated by PI3K‐AKT signaling
Authors: Gao Yi , Yang Jianjian , Cai Yixin , Fu Shengling , Zhang Ni , Fu Xiangning , Li Lequn
Published: March 2018

IFN‐γ plays a crucial role in anti‐tumor responses and also induces expression of PD‐L1, a well‐established inhibitor of anti‐tumor immune function. Understanding how molecular signaling regulates the function of IFN‐γ might improve its anti‐tumor efficacy. Here, we show that the tumor expression of IFN‐γ expression alone has no significant prognostic value in patients with locally advanced lung adenocarcinoma. Surprisingly, patients with tumors expressing both IFN‐γ and PD‐L1 have the best prognosis compared to those with tumors expressing IFN‐γ or PD‐L1 alone. Transcriptome analysis demonstrated that tumor tissues expressing IFN‐γ display gene expression associated with suppressed cell cycle progression and expansion. Unexpectedly this profile was observed in PD‐L1+ but not PD‐L1− tumors. The current concept is that PD‐L1 functions as a shield protecting tumor cells from cytolytic T cell (CTL)‐mediated anti‐tumor progression. However, our data indicate that PD‐L1 expression in the presence of IFN‐γ might serve as biomarker for the sensitivity of tumors to the inhibitory effect of IFN‐γ. Mechanistic analysis revealed that in lung adenocarcinoma cells IFN‐γ‐induced activation of JAK2‐STAT1 and PI3K‐AKT pathways. The activation of JAK2‐STAT1 is responsible for the anti‐proliferative effect of IFN‐γ. Inhibition of PI3K downregulated PD‐L1 expression and enhanced the anti‐proliferative effect of IFN‐γ, suggesting that blockade of PI3K might maximize the IFN‐γ‐mediated anti‐tumor effect. Our findings provide evidence for crosstalk between JAK2‐STAT1 and PI3K‐AKT pathways in response to IFN‐γ in lung adenocarcinoma and have implications for the design of combinatorial targeted therapy and immunotherapy for the treatment of lung adenocarcinoma.
Anaphylactic reaction to an ultrasound contrast agent (Lumason) in a patient with systemic mastocytosis
Authors: Olson Michael C. , Atwell Thomas D. , Knudsen John M.
Published: March 2018

Severe adverse reactions to ultrasound (US) contrast agents are rare, and only a few cases of anaphylaxis following the administration of US contrast agents have been reported, often without a defined etiology. We present a case of anaphylactic reaction to the injection of an US contrast agent in a patient with systemic mastocytosis, which highlights the disorder as a possible risk factor warranting additional consideration prior to performing a contrast‐enhanced US examination.
1H‐MRS for the assessment of renal triglyceride content in humans at 3T: A primer and reproducibility study
Authors: Dekkers Ilona A. , de Heer Paul , Bizino Maurice B. , de Vries Aiko P.J. , Lamb Hildo J.
Published: March 2018

Background

Renal steatosis (fatty kidney) is a potential biomarker for obesity‐related renal disease; however, noninvasive assessment of renal fat content remains a technical challenge.

Purpose

To evaluate reproducibility and explore clinical application of renal metabolic imaging for the quantification of renal triglyceride content (TG) using proton magnetic resonance spectroscopy (1H‐MRS).

Study type

Reproducibility and clinical cohort study.

Population

Twenty‐three healthy volunteers (mean age 30.1 ± 13.4 years) and 15 patients with type 2 diabetes mellitus (T2DM) (mean age 59.3 ± 7.0 years).

Field Strength/Sequence

3T, single‐voxel point resolved spectroscopy (PRESS).

Assessment

Intra‐ and interexamination reproducibility of renal TG was assessed in healthy volunteers, and compared to T2DM patients. Intraexamination differences were obtained by repeating the 1H‐MRS measurement directly after the first 1H‐MRS without repositioning of the subject or changing surface coil and measurement volumes. Interexamination variability was studied by repeating the scan protocol after removal and replacement of the subject in the magnet, and subsequent repositioning of body coil and measurement volumes.

Statistical Tests

Reproducibility was determined using Pearson's correlation and Bland–Altman analyses. Differences in TG% between healthy volunteers and T2DM patients were assessed using the Mann–Whitney U‐test.

Results

After logarithmic (log) transformation, both intraexamination (r = 0.91, n = 19) and interexamination (r = 0.73, n = 9) measurements of renal TG content were highly correlated with the first renal TG measurements. Intraexamination and interexamination limits of agreement of renal log TG% were respectively [−1.36%, + 0.84%] and [−0.77%, + 0.62%]. Backtransformed limits of agreement were [−0.89%,+0.57%] and [−0.55%, + 0.43%] multiplied by mean TG for intra‐ and interexamination measurements. Overall median renal TG content was 0.12% [0.08, 0.22; 25th percentile, 75th percentile] in healthy volunteers and 0.20% [0.13, 0.22] in T2DM patients (P = 0.08).

Data Conclusion

Renal metabolic imaging using 3T 1H‐MRS is a reproducible technique for the assessment of renal triglyceride content.

Level of Evidence: 3

Technical Efficacy: Stage 1

J. MAGN. RESON. IMAGING 2018;48:507–513.
Synthesis and Properties of Quaternary Ammonium Surfactants Based on Alkylamine, Propylene Oxide, and 2‐Chloroethanol
Authors: Asadov Ziyafaddin H. , Ahmadova Gulnara A. , Rahimov Ravan A. , Abilova Aygul Z. , Zargarova Sevda H. , Zubkov Fedor I.
Published: March 2018

New quaternary ammonium salts are synthesized by octylamine, nonylamine, dodecylamine, and hexadecylamine reacting with propylene oxide at a mole ratio of 1:2, followed by reaction with 2‐chloroethanol. By tensiometric measurements of aqueous solutions, their surface activity has been determined. Using the results of these measurements and electroconductometric studies, important parameters such as critical micelle concentration (CMC), efficiency of surfactant adsorption, surface pressure at the CMC, changes of Gibbs free energies for micelle formation, and adsorption were estimated. By application of the Gibbs adsorption isotherm, indices such as maximum surface excess concentration and minimum surface area/molecule at the air–water interface were also calculated. Petroleum‐collecting properties of these surfactants were investigated. Among these quaternary ammonium surfactants, the surfactant based on dodecylamine, propylene oxide, and 2‐chloroethanol exhibits the highest petroleum‐collecting capacity.