bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shape Modification of Germanium Nanowires during Ion Irradiation and Subsequent Solid‐Phase Epitaxial Growth
Authors: Camara Osmane , Hanif Imran , Tunes Matheus , Harrison Robert , Greaves Graeme , Donnelly Stephen , Hinks Jonathan 
Published: May 2018

AbstractDuring ion irradiation which is often used for the purposes of bandgap engineering, nanostructures can experience a phenomenon known as ion‐induced bending (IIB). The mechanisms behind this permanent deformation are the subject of debate. In this work, germanium nanowires are irradiated with 30 or 70 keV xenon ions to induce bending either away from or toward the ion beam. By comparing experimental results with Monte Carlo calculations, the direction of the bending is found to depend on the damage profile over the cross section of the nanowire. After irradiation, the nanowires are annealed at temperatures up to 440 °C triggering solid‐phase epitaxial growth (SPEG) causing further modification to the deformed nanowires. After IIB, it is observed that nanowires which had bent away from the ion beam then straighten during SPEG while those which had bent toward the ion beam bend even more. This is attributed to differences in the mechanisms responsible for the ion‐beam‐induced bending in opposite directions. Thus, the results reported here give insights into the mechanisms causing the IIB of nanowires and demonstrate how to predict the evolution of nanowires under irradiation and annealing. Finally, they show that, under certain conditions, the bending can even be removed via SPEG.
Versatile MnO2/CNT Putty‐Like Composites for High‐Rate Lithium‐Ion Batteries
Authors: Shen Lei , Dong Qiuchun , Zhu Guoyin , Dai Ziyang , Zhang Yizhou , Wang Wenjun , Dong Xiaochen 
Published: May 2018

AbstractA facile and simple method is developed to synthesize putty‐like MnO2/carbon nanotube (CNT) nanostructured composite which shows promising performance as the anode for lithium‐ion batteries (LIBs). The interwoven structure between CNTs and MnO2 enables excellent putty‐like processability, which can be easily molded to various shapes or rolled to a flexible film with different thickness. Furthermore, the morphology and structure of the composite can be easily controlled by adjusting the mass ratio of MnO2 to CNT. Serving as anode materials in LIBs, a high‐specific capacity of 796 mAh g−1 is achieved at a current density of 500 mA g−1 with a potential window from 0 to 3.0 V. And a specific capacity of 236 mA h g−1 is maintained even at a high current density of 10 A g−1. The high‐specific capacity and outstanding high‐rate performance of the material are attributed to the layered structure with unimpeded Li ions diffusion channels, high electron transport efficiency from the interlayered CNTs, and the high stability and flexibility of the skeleton. This work provides an insight for the scalable preparation of novel electrode materials with both enhanced electrochemical performance and increased mechanical properties/flexibility for future multifunctional energy storage devices.
Copper‐Catalyzed Aerobic Oxidative Cyclization of Anilines, Aryl Methyl Ketones and DMSO: Efficient Assembly of 2‐Arylquinolines
Authors: Liu Yufeng , Hu Yuqun , Cao Zhongzhong , Zhan Xi , Luo Weiping , Liu Qiang , Guo Cancheng 
Published: May 2018

AbstractA Cu‐catalyzed C−H cyclization of simple anilines with ketones and DMSO as a one‐carbon source has been developed. Using an aerobic oxidative protocol, a number of ketones and anilines could be easily converted to 2‐arylquinolines, rather than 4‐arylquinolines, thus providing a highly atom‐economical and simple approach to biologically significant 2‐arylquinolines. Based on the preliminary experiments, a plausible mechanism is proposed.magnified image
Enzymatic Desymmetrization of 19‐nor‐Vitamin D3 A‐Ring Synthon Precursor: Synthesis, Structure Elucidation, and Biological Activity of 1α,25‐Dihydroxy‐3‐epi‐19‐nor‐vitamin D3 and 1β,25‐Dihydroxy‐19‐nor‐vitamin D3
Authors: González‐García Tania , Verstuyf Annemieke , Verlinden Lieve , Fernández Susana , Ferrero Miguel 
Published: May 2018

AbstractIn a search for novel vitamin D derivatives of potential therapeutic value, structurally simple but synthetically challenging A‐ring epimers of the 19‐nor‐Calcitriol [19‐nor‐1α,25‐(OH)2‐D3] at C1 and C3 were efficiently synthesized. Both analogues (1‐epi‐ and 3‐epi‐19‐nor‐Calcitriol) were obtained through a convergent synthesis starting from cis,cis‐1,3,5‐cyclohexanetriol and the protected 25‐hydroxy Grundmann′s ketone. After Julia‐Kocienski coupling of the corresponding C,D‐ring/side chain sulfone fragment with the A‐ring ketone moiety, both vitamin D analogues were isolated. The critical point was how to determine the structural configuration of both diastereoisomers since similar 1H NMR spectra were observed. For that, a biocatalytic approach was crucial in the synthesis of orthogonally protected derivatives. NMR spectroscopy allows the unambiguous identification of these compounds and as a result the structural elucidation of the desired vitamin D diastereomeric analogues. Affinity studies demonstrated that these 1,25‐19‐nor analogues have a very low affinity for the vitamin D receptor compared with 1α,25‐dihydroxyvitamin D3 or 1α,25‐dihydroxy‐19‐nor‐vitamin D3. In addition, these analogues have a lower binding affinity for the human vitamin D binding protein than the natural hormone. In vitro cell culture studies revealed that synthesized analogues were less active than 1α,25‐dihydroxyvitamin D3 in inhibiting cell proliferation.magnified image
CuII Complex of a 1,10‐Phenanthroline‐Based Pincer as an Efficient Catalyst for Oxidative Cross Dehydrogenative Coupling of Carboxylic Acids with Unactivated Alkanes
Authors: Jash Upasona , Chakraborty Gargi , Sinha Suman , Sikari Rina , Mondal Rakesh , Paul Nanda D. 
Published: May 2018

AbstractSynthesis of a well‐defined CuII complex 1 featuring a phenanthroline‐based tridentate scaffold, 2‐pyrazol‐(1,10‐phenanthroline) (L) and studies of its catalytic activity in the cross dehydrogenative coupling of acids with common alkanes to form allylic esters are reported. The complex 1 showed excellent catalytic activity in the oxidative cross dehydrogenative coupling of a wide variety of alkanes with acids to form the corresponding allylic esters in moderate to high yields. Several control experiments along with spectroscopic studies were carried out to characterize catalyst 1 and to explore the plausible mechanistic pathways.
Functionalized Cyclopentadienyl Ligands and Their Substituent Effects on a Rhodium(III)‐Catalyzed Oxidative [4+2] Annulation of Indole‐ and Pyrrole‐1‐Carboxamides with Alkynes
Authors: Yamada Takayuki , Shibata Yu , Tanaka Ken 
Published: May 2018

AbstractThe effect of substituents on carbamoylmethyl‐cyclopentadienyl (CpA) ligands on the neutral rhodium(III)‐catalyzed oxidative [4+2] annulation of indole‐ and pyrrole‐1‐carboxamides with alkynes, in which the C−H bond cleavage is the partially rate‐limiting step, was investigated. As a result, in the reactions with terminal alkynes, a rhodium(III) complex with a dimethyl‐substituted CpA ligand (CpA3) showed high catalytic activity and improved the regioselectivity as compared to a commercially available Cp*RhIII complex. On the other hand, in reactions with internal alkynes, a rhodium(III) complex with a diphenyl‐substituted CpA ligand (CpA1 or CpA2) showed high catalytic activity, which is comparable to the activity of the Cp*RhIII complex. Interestingly, a rhodium(III) complex with an electron‐deficient di(ethoxycarbonyl)‐substituted Cp ligand (CpE) that shows high catalytic activity toward the annulation of benzamides with internal alkynes, in which the C−H cleavage is rate‐limiting, showed low catalytic activity toward the reactions with both terminal and internal alkynes. The ligand effects above provide important guidelines for the application of our CpA and CpE ligands to the rhodium(III)‐catalyzed C−H bond functionalization reactions.
Transition‐Metal‐Free Direct C−H Silylation of Electron‐Deficient Heteroarenes with Hydrosilanes via a Radical Mechanism
Authors: Sakamoto Ryu , Nguyen Bich‐Ngoc , Maruoka Keiji 
Published: May 2018

AbstractA direct C−H silylation of electron‐deficient heteroarenes was achieved via a radical reaction between pyridines or other N‐heterocycles and hydrosilanes in the presence of acetic acid, di‐tert‐butyl peroxide, and tert‐butyl mercaptan. The present approach allows the direct introduction of trialkylsilyl substituents at the ortho‐position of various electron‐deficient heteroarenes.
Rheological characterization of polyethylene/polyester recycled tire fibers/ground tire rubber composites
Authors: Moghaddamzadeh Siavosh , Rodrigue Denis 
Published: May 2018

ABSTRACTThe rheological behavior of polyester recycled tire fibers (RTF) mixed with ground tire rubber and linear low density polyethylene (LLDPE) with and without styrene–ethylene–butylene–styrene grafted maleic anhydride (SEBS‐g‐MA) as a compatibilizer was investigated in the melt (small amplitude oscillatory shear) and solid (dynamic mechanical analysis) states. In particular, the effect of RTF content (10, 25, and 50 wt %), extrusion screw speed (110, 180, and 250 rpm), and temperature profiles (extrusion and injection molding) was studied. In general, it was found that the rheological properties in the melt state (modulus and viscosity) of the uncompatibilized samples increased with RTF content, but higher values were obtained when SEBS‐g‐MA was added due to better interfacial coupling. Although similar results were obtained in the solid state, it was shown that melt rheology can better explain the variations as the measurements are more sensitive to the interface quality since the matrix contribution is less important. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46563.
Kinetics studies and characterization of poly(furfuryl alcohol) for use as bio‐based furan novolacs
Authors: Sadler Joshua M. , Yeh In‐Chul , Toulan Faye R. , McAninch Ian M. , Rinderspacher Berend C. , La Scala John J. 
Published: May 2018

ABSTRACTPoly(furfuryl alcohol) (PFA) is an attractive target for the development of bio‐based novolac resins. However, control of the polycondensation reaction is not well understood and side reactions are an important factor for PFA and the development of new resins. The polymerization reactions and kinetics of furfuryl alcohol and 2‐furyl ethanol into polymeric resins are detailed in this work. Nuclear magnetic resonance spectroscopy analysis of reaction kinetics, molecular weight analysis, and rheology analysis confirm that the polymerization reaction rate of 2‐furyl ethanol is much faster than that of furfuryl alcohol because the addition of this methyl group serves to stabilize the carbocation transition state. Side reactions, such as Diels–Alder crosslinking and in particular branching, are quantified and were found to be much more prevalent in the polymerization of PFA. The glass transition temperature was measured to be 376 K for PFA and only 294 K for poly(2‐furyl ethanol). Molecular dynamics simulations showed that the alternative structure that forms in PFA that causes branching results in greater backbone rigidity causing its higher glass transition temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46608.
Mitochondrial DNA short tandem repeats unveil hidden population structuring and migration routes of an endangered marine turtle
Authors: Tikochinski Yaron , Bradshaw Phil , Mastrogiacomo Angela , Broderick Annette , Daya Alon , Demetropoulos Andreas , Demetropoulos Simon , Eliades Nicolas‐George , Fuller Wayne , Godley Brendan , Kaska Yakup , Levy Yaniv , Snape Robin , Wright Lucy , Carreras Carlos 
Published: May 2018

Abstract

The assessment of the composition and dynamics of endangered populations is crucial for management and conservation, and appropriate genetic markers are critical.
The genetic structuring of the Mediterranean green turtle (Chelonia mydas) populations and the origin of the stranded animals found along the Israeli coast was investigated using new highly polymorphic short tandem repeat (STR) markers.
The structuring of nesting populations was studied using pairwise genetic distances and a principal coordinates analysis (PCoA).
The contribution of the different nesting populations to the stranded sample was assessed by using a mixed‐stock analysis.
A clear population genetic structure, not detected before, has been revealed. The four nesting populations are genetically well differentiated, and thus should be considered as different management units. The populations from Turkey and Israel showed higher resemblance, despite residing at opposite ends of the Mediterranean distribution. The Turkish nesting population is the main source of the stranded turtles sampled along the Israeli shore, confirming that individuals from this population migrate from north to south along the eastern shore of the Mediterranean, as previously shown by telemetry studies.
The use of a highly polymorphic haplotyping method enabled the detection of a clear genetic structuring of the green turtle populations in the eastern Mediterranean Sea that was not revealed in previous studies, demonstrating the importance of marker selection in population genetics.
The analysis of the genetic composition of the stranded turtles allowed us to investigate the migration patterns from nesting to foraging areas, supporting previous satellite‐tracking and stable‐isotope results.
These results will help to delineate conservation management units for the species in the Mediterranean, and reveal connectivity among beaches and mixed aggregations.
Acceptability and caregiver‐reported outcomes for young children with autism spectrum disorder whose parents attended a preventative population‐based intervention for anxiety: A pilot study
Authors: Bischof Natalie L. , Rapee Ronald M. , Hudry Kristelle , Bayer Jordana K. 
Published: May 2018

This pilot study explored acceptability to parents and outcomes for children of a preventive intervention for anxiety problems in pre‐schoolers with autism spectrum disorder (ASD) who were an identified sub‐group within a population‐based randomised trial of the Cool Little Kids parenting group programme. The population trial included 545 temperamentally inhibited pre‐schoolers recruited across eight economically diverse areas of Melbourne, Australia. Within this sample, 26 parents reported that their child had received an ASD diagnosis. Trial measures included baseline inhibited temperament and developmental problems, post‐intervention feedback on the programme, and caregiver‐reported child mental health outcomes (anxiety diagnoses and internalising symptoms) at 1‐ and 2‐year follow‐up. Sample retention for the children with ASD over 2 years was strong (92%). At follow‐up, fewer intervention than control children with ASD had anxiety disorders after 1 year (% (n): 25 (3) vs. 77 (10), P = .028) and separation anxiety symptoms after 2 years (M (SD): 4.22 (2.68) vs. 9.38 (5.91), P = .017). Similar effects favouring the intervention group were apparent across other child emotional outcome measures but without statistical significance in this small sample. Parents of the children with ASD reported that Cool Little Kids was “quite useful” in relation to their child's anxiety but also gave feedback that they would appreciate some tailoring of programme content to the context of ASD. These pilot findings suggest Cool Little Kids may be helpful for reducing comorbid anxiety in pre‐schoolers with ASD. Further research is warranted to develop an ASD‐specific adaptation which can be trialled with a larger sample of children with confirmed ASD diagnosis. Trial registration ISRCTN30996662 http://www.isrctn.com/ISRCTN30996662. Autism Res 2018, 11: 1166–1174. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryMany children with autism spectrum disorder (ASD) also have anxiety. This pilot study explored acceptability to parents and outcomes for pre‐schoolers with ASD of a parenting group programme to prevent anxiety problems. Among the sample of 26 pre‐schoolers with ASD, we found reduced anxiety disorders and separation symptoms when their parents had received the intervention, as reported by caregivers in checklists and clinical interviews. Parents gave feedback that the programme was useful but suggested content be adapted to the context of ASD.
Kraftwerk Lausward, Düsseldorf
Authors: Bollinger Klaus , Grohmann Manfred , Ruppert Simon 
Published: May 2018

AbstractDas neue Gaskraftwerk auf der „Lausward“ hat eine attraktive Gebäudehülle inklusive einer neuen Aussichtsplattform erhalten, die sowohl das Stadtbild wie auch den Bereich des Düsseldorfer Hafens positiv an seinem auch zukünftig eher industriell geprägten westlichen Rand stärkt.Das Architekturbüro kadawittfeldarchitektur hat nach gewonnenem Wettbewerb (2013) eine Hülle aus nebeneinanderstehenden, unterschiedlich großen Stahlrahmen realisiert, die den einzelnen Gebäudeteilen des neuen Kraftwerks ein gemeinsames Kleid verleihen. Die einzelnen Module können auf jegliche Anforderungen aus dem Inneren reagieren. Gleichzeitig wird das große Gesamtvolumen durch die Rhythmisierung verträglich gegliedert.Das abschließende und größte Rahmenelement im Nordosten der Anlage bildet das sogenannte „Stadtfenster“, eine 60 m hohe und 38 m breite, beidseitig komplett verglaste Einhausung des Kraftwerks‐Schornsteins. Über einen Aufzug gelangt man auf ca. 45 m Höhe zu einer Aussichtsplattform, von der man nach Süden bis nach Köln und nördlich über den Rhein auf Düsseldorf blicken kann.Der vorliegende Bericht beschäftigt sich insbesondere mit dem Entwurf und der Konstruktion dieses besonderen Bauteils.
FM19G11 inhibits O6‐methylguanine DNA‐methyltransferase expression under both hypoxic and normoxic conditions
Authors: You Chao‐guo , Sheng Han‐song , Xie Chao‐ran , Zhang Nu , Zheng Xue‐sheng 
Published: May 2018

AbstractFM19G11 is a small molecular agent that inhibits hypoxia‐inducible factor‐1‐alpha (HIF‐1α) and other signaling pathways. In this study, we characterized the modulating effects of FM19G11 on O6‐methylguanine DNA‐methyltransferase (MGMT), the main regulator of temozolomide (TMZ) resistance in glioblastomas. This study included 2 MGMT‐positive cell lines (GBM‐XD and T98G). MGMT promoter methylation status, mRNA abundance, and protein levels were determined before and after FM19G11 treatment, and the roles of various signaling pathways were characterized. Under hypoxic conditions, MGMT mRNA and protein levels were significantly downregulated by FM19G11 via the HIF‐1α pathway in both GBM‐XD and T98G cells. In normoxic culture, T98G cells were strongly positive for MGMT, and MGMT expression was substantially downregulated by FM19G11 via the NF‐κB pathway. In addition, TMZ resistance was reversed by treatment with FM19G11. Meanwhile, FM19G11 has no cytotoxicity at its effective dose. FM19G11 could potentially be used to counteract TMZ resistance in MGMT‐positive glioblastomas.
Catalytic Methane Decomposition to Hydrogen over a Surface‐Protected Core‐Shell Ni@SiO2 Catalyst
Authors: Wu Shan-Luo , Yang Ren-Xuan , Wey Ming-Yen 
Published: May 2018

AbstractMethane decomposition is a promising method to obtain COx‐free hydrogen. The main difficulty of this process is that the produced carbon would deposit on the active phase of the catalyst, leading to catalyst deactivation. In this study, a core‐shell‐structured composite catalyst comprising highly active Ni nanoparticles (NP) as core and mesoporous silica as shell is introduced. The silica shells were synthesized by using cetyltrimethylammonium bromide as template and tetraethyl orthosilicate as precursor. Ni NP and Ni@SiO2 were examined as catalysts for hydrogen production by methane decomposition at different temperatures and gas hourly space velocities. The results show that the core‐shell catalyst exhibited much better stability in methane decomposition than Ni NP without silica shell and a traditional supported catalyst.
A Two‐Step Process for the Synthesis of Hydroxytyrosol
Authors: Ziosi Paolo , Paolucci Claudio , Santarelli Francesco , Tabanelli Tommaso , Passeri Sauro , Cavani Fabrizio , Righi Paolo 
Published: May 2018

AbstractA new process for the synthesis of hydroxytyrosol (3,4‐dihydroxyphenylethanol), the most powerful natural antioxidant currently known, by means of a two‐step approach is reported. Catechol is first reacted with 2,2‐dimethoxyacetaldehyde in basic aqueous medium to produce the corresponding mandelic derivative with >90 % conversion of the limiting reactant and about 70 % selectivity to the desired para‐hydroxyalkylated compound. Thereafter, the intermediate is hydrogenated to hydroxytyrosol by using a Pd/C catalyst, with total conversion of the mandelic derivative and 68 % selectivity. This two‐step process is the first example of a synthetic pathway for hydroxytyrosol that does not involve the use of halogenated components or reduction methodologies that produce stoichiometric waste. It also avoids the complex procedure currently used for hydroxytyrosol purification when it is extracted from wastewater of olive oil production.
Integration of CO2 Reduction with Subsequent Carbonylation: Towards Extending Chemical Utilization of CO2
Authors: Lang Xian‐Dong , He Liang‐Nian 
Published: May 2018

AbstractCurrently, it still remains a challenge to amplify the spectrum of chemical fixation of CO2, although enormous progress has been achieved in this field. In view of the widespread applications of CO in a myriad of industrial carbonylation processes, an alternative strategy is proposed in which CO2 reduction to CO is combined with carbonylation with CO generated ex situ, which affords efficiently pharmaceutically and agrochemically attractive molecules. As such, CO2 in this study was efficiently reduced by triphenysilane using CsF to CO in a sealed two‐chamber reactor. Subsequently, palladium‐catalyzed aminocarbonylation, carbonylative Sonogashira coupling of aryl iodides, and rhodium(I)‐mediated Pauson–Khand‐type reaction proceeded smoothly to yield amides, alkynones, and bicyclic cyclopentenones, respectively. Furthermore, the formed alkynones can further be successfully converted to a series of heterocycles, for example, pyrazoles, 3a‐hydroxyisoxazolo[3,2‐a]isoindol‐8‐(3aH)‐one derivatives and pyrimidines in moderate yields. The striking features of this protocol include operational simplicity, high efficiency, and relatively broad application scope, which represents an alternative avenue for CO2 transformation.
Reductive Cleavage Method for Quantitation of Monolignols and Low‐Abundance Monolignol Conjugates
Authors: Regner Matt , Bartuce Allison , Padmakshan Dharshana , Ralph John , Karlen Steven D. 
Published: May 2018

AbstractInvited for this month's cover is the group of Prof. John Ralph at the University of Wisconsin–Madison. The image shows the fragmentation of various lignins into monomeric components using the derivatization followed by reductive cleavage (DFRC) method, with the included mechanism providing the details for the derivatization of these lignins with acetyl bromide and their subsequent reductive cleavage using elemental zinc. The Communication itself is available at 10.1002/cssc.201800617.