bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrafast Zn2+ Intercalation and Deintercalation in Vanadium Dioxide
Authors: Ding Junwei , Du Zhiguo , Gu Linqing , Li Bin , Wang Lizhen , Wang Shiwen , Gong Yongji , Yang Shubin
Published: May 2018

Although rechargeable aqueous zinc‐ion batteries have attracted extensive interest due to their environmental friendliness and low cost, they still lack suitable cathodes with high rate capabilities, which are hampered by the intense charge repulsion of bivalent Zn2+. Here, a novel intercalation pseudocapacitance behavior and ultrafast kinetics of Zn2+ into the unique tunnels of VO2 (B) nanofibers in aqueous electrolyte are demonstrated via in situ X‐ray diffraction and various electrochemical measurements. Because VO2 (B) nanofibers possess unique tunnel transport pathways with big sizes (0.82 and 0.5 nm2 along the b‐ and c‐axes) and little structural change on Zn2+ intercalation, the limitation from solid‐state diffusion in the vanadium dioxide electrode is eliminated. Thus, VO2 (B) nanofibers exhibit a high reversible capacity of 357 mAh g−1, excellent rate capability (171 mAh g−1 at 300 C), and high energy and power densities as applied for zinc‐ion storage.
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

During 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

A 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

A 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.

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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

In 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.

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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

Synthesis 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

The 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

A 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

The 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

Poly(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

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.
“Why did you really do it?” A mixed‐method analysis of the factors underpinning motivations to register as a body donor
Authors: Cornwall Jon , Poppelwell Zoe , McManus Ruth
Published: May 2018

Individuals who register as body donors do so for various reasons, with aiding medical science a common motivation. Despite awareness of several key reasons for donation, there are few in‐depth explorations of these motivations to contextualize persons' reasons for donating. This study undertakes a mixed‐method exploration of motivations for body donation to facilitate deeper understanding of the reasons underpinning donor registration. A survey of all newly registered body donors at a New Zealand university was performed over a single year. The survey included basic demographic information, a categorical question on reason for donation, a free‐text question on donation motivation, and a free‐text question allowing “other” comments on body donation. Basic statistical analysis was performed on demographic and categorical data, and thematic analysis used on free‐text responses. From 169 registrants, 126 people (average age 70.5 years; 72 female) returned completed surveys (response rate 75%). Categorical data indicate a primary motivation of aiding medical science (86%). Fifty‐one respondents (40%) provided free‐text data on motivation, with other comments related to motivation provided by forty‐one (33%). Common themes included reference to usefulness, uniqueness (pathophysiology and anatomy), gift‐giving, kinship, and impermanence of the physical body. Consistent with previous studies, the primary reason for body donation was aiding medical science, however underpinning this was a complex layer of themes and sub‐themes shaping motivations for choices. Findings provide important information that can guide development of robust informed consent processes, aid appropriate thanksgiving service delivery, and further contextualize the importance of medical professionals in body donation culture.
The design and evaluation of a master of science program in anatomical sciences at Queen's University Canada
Authors: Kolomitro Klodiana , MacKenzie Leslie W. , Wiercigroch David , Godden Lorraine
Published: May 2018

The purpose of this study was to describe the design and evolution of a unique and successful Master of Science program in anatomical sciences at one Canadian post‐secondary institution and to evaluate its long‐term impact on student learning. This program prepares students to teach anatomy and design curricula in the anatomical sciences and is structured around three pillars of competency—content (disciplinary knowledge and transferable skills), pedagogy, and inquiry. Graduates of the program from the last ten years were surveyed, to better understand the knowledge, skills, and habits of mind they have adopted and implemented since completion. Interest was taken in identifying aspects of the program that students found particularly beneficial and areas that needed to be further developed. Based on the findings, this program has been a highly valuable experience for the graduates especially in helping them develop transferable skills, and grow as individuals. The hope is that other institutions that have similar programs in place or are considering developing them would benefit from this description of the program design and the sharing of the lessons learned.
Research output and impact of the fields of management, economics, and sociology in spain and france: An analysis using google scholar and scopus
Authors: Gantman Ernesto R. , Dabós Marcelo P.
Published: May 2018

Because of a greater coverage of documentary sources in many languages that is greater than that of traditional bibliographic databases, Google Scholar is an ideal tool for examining the social sciences in non‐Anglophone countries. We have therefore used it to study the scholarly output and impact of three scientific disciplines, management, economics, and sociology, in Spain and France, comparing some of the results with those retrieved with Scopus. Our findings show that scientific articles are the predominant form of scholarly communication in Google Scholar for our selected fields and countries. In addition, our results indicate that in Google Scholar the vernacular languages of each country are more used than English in all cases, but economics in France. The opposite occurs in Scopus, except for the case of sociology articles in France We also show that books receive on average more citations than other published documents in Google Scholar. Finally, we demonstrate that publishing in English is associated with greater scholarly impact, except for the case of France in Google Scholar for articles in sociology and books in the three fields.
Co‐saved, co‐tweeted, and co‐cited networks
Authors: Didegah Fereshteh , Thelwall Mike
Published: May 2018

Counts of tweets and Mendeley user libraries have been proposed as altmetric alternatives to citation counts for the impact assessment of articles. Although both have been investigated to discover whether they correlate with article citations, it is not known whether users tend to tweet or save (in Mendeley) the same kinds of articles that they cite. In response, this article compares pairs of articles that are tweeted, saved to a Mendeley library, or cited by the same user, but possibly a different user for each source. The study analyzes 1,131,318 articles published in 2012, with minimum tweeted (10), saved to Mendeley (100), and cited (10) thresholds. The results show surprisingly minor overall overlaps between the three phenomena. The importance of journals for Twitter and the presence of many bots at different levels of activity suggest that this site has little value for impact altmetrics. The moderate differences between patterns of saving and citation suggest that Mendeley can be used for some types of impact assessments, but sensitivity is needed for underlying differences.
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 Summary

Many 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

Das 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

FM19G11 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

Methane 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

A 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

Currently, 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

Invited 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.
Cell dynamic morphology classification using deep convolutional neural networks
Authors: Li Heng , Pang Fengqian , Shi Yonggang , Liu Zhiwen
Published: May 2018

Cell morphology is often used as a proxy measurement of cell status to understand cell physiology. Hence, interpretation of cell dynamic morphology is a meaningful task in biomedical research. Inspired by the recent success of deep learning, we here explore the application of convolutional neural networks (CNNs) to cell dynamic morphology classification. An innovative strategy for the implementation of CNNs is introduced in this study. Mouse lymphocytes were collected to observe the dynamic morphology, and two datasets were thus set up to investigate the performances of CNNs. Considering the installation of deep learning, the classification problem was simplified from video data to image data, and was then solved by CNNs in a self‐taught manner with the generated image data. CNNs were separately performed in three installation scenarios and compared with existing methods. Experimental results demonstrated the potential of CNNs in cell dynamic morphology classification, and validated the effectiveness of the proposed strategy. CNNs were successfully applied to the classification problem, and outperformed the existing methods in the classification accuracy. For the installation of CNNs, transfer learning was proved to be a promising scheme. © 2018 International Society for Advancement of Cytometry
An optimized protocol for large‐scale in situ sampling and analysis of volatile organic compounds
Authors: Nair Jyothi V. , Shanmugam Pragadheesh V. , Karpe Snehal D. , Ramakrishnan Uma , Olsson Shannon
Published: May 2018

Chemical ecology is an ever‐expanding field with a growing interest in population‐ and community‐level studies. Many such studies are hindered due to lack of an efficient and accelerated protocol for large‐scale sampling and analysis of chemical compounds. Here, we present an optimized protocol for such large‐scale study of volatiles. A large‐scale in situ study to understand role of semiochemicals in variation in mating success of lekking blackbuck was conducted. Suitable methods for sampling and statistical analysis were identified by testing and comparing the efficiencies of available techniques to reduce analysis time while retaining sensitivity and comprehensiveness. Solid‐phase extraction using polydimethylsiloxane, analysis using a semiautomated detection of retention time and base peak, and statistical analysis using random forest algorithm were identified as the most efficient methods for large‐scale in situ sampling and analysis of volatiles. The protocol for large‐scale volatile analysis can facilitate evolutionary and metaecological studies of volatiles in situ from all types of biological samples. The protocol has potential for wider application with the analysis and interpretation methods being suitable for all kinds of semiochemicals, including nonvolatile chemicals.
DNA methylation in adults and during development of the self‐fertilizing mangrove rivulus, Kryptolebias marmoratus
Authors: Fellous Alexandre , Labed‐Veydert Tiphaine , Locrel Mélodie , Voisin Anne‐Sophie , Earley Ryan L. , Silvestre Frederic
Published: May 2018

In addition to genetic variation, epigenetic mechanisms such as DNA methylation might make important contributions to heritable phenotypic diversity in populations. However, it is often difficult to disentangle the contributions of genetic and epigenetic variation to phenotypic diversity. Here, we investigated global DNA methylation and mRNA expression of the methylation‐associated enzymes during embryonic development and in adult tissues of one natural isogenic lineage of mangrove rivulus fish, Kryptolebias marmoratus. Being the best‐known self‐fertilizing hermaphroditic vertebrate affords the opportunity to work with genetically identical individuals to examine, explicitly, the phenotypic effects of epigenetic variance. Using the LUminometric Methylation Assay (LUMA), we described variable global DNA methylation at CpG sites in adult tissues, which differed significantly between hermaphrodite ovotestes and male testes (79.6% and 87.2%, respectively). After fertilization, an immediate decrease in DNA methylation occurred to 15.8% in gastrula followed by re‐establishment to 70.0% by stage 26 (liver formation). Compared to zebrafish, at the same embryonic stages, this reprogramming event seems later, deeper, and longer. Furthermore, genes putatively encoding DNA methyltransferases (DNMTs), Ten‐Eleven Translocation (TET), and MeCP2 proteins showed specific regulation in adult gonad and brain, and also during early embryogenesis. Their conserved domains and expression profiles suggest that these proteins play important roles during reproduction and development. This study raises questions about mangrove rivulus’ peculiar reprogramming period in terms of epigenetic transmission and physiological adaptation of individuals to highly variable environments. In accordance with the general‐purpose genotype model, epigenetic mechanisms might allow for the expression of diverse phenotypes among genetically identical individuals. Such phenotypes might help to overcome environmental challenges, making the mangrove rivulus a valuable vertebrate model for ecological epigenetic studies. The mangrove rivulus, Kryptolebias marmoratus, is the best‐known self‐fertilizing hermaphroditic vertebrate that allows to work with genetically identical individuals to examine, explicitly, the phenotypic effects of epigenetic variance. The reprogramming event is later, more dramatic and longer than in other described vertebrates. High evolutionary conservation and expression patterns of DNMT, TET, and MeCP2 proteins in K. marmoratus suggest biological roles for each member in gametogenesis and development.
Parallel evolution of site‐specific changes in divergent caribou lineages
Authors: Horn Rebekah L. , Marques Adam J. D. , Manseau Micheline , Golding Brian , Klütsch Cornelya F. C. , Abraham Ken , Wilson Paul J.
Published: May 2018

The parallel evolution of phenotypes or traits within or between species provides important insight into the basic mechanisms of evolution. Genetic and genomic advances have allowed investigations into the genetic underpinnings of parallel evolution and the independent evolution of similar traits in sympatric species. Parallel evolution may best be exemplified among species where multiple genetic lineages, descended from a common ancestor, colonized analogous environmental niches, and converged on a genotypic or phenotypic trait. Modern North American caribou (Rangifer tarandus) originated from three ancestral sources separated during the Last Glacial Maximum (LGM): the Beringian–Eurasian lineage (BEL), the North American lineage (NAL), and the High Arctic lineage (HAL). Historical introgression between the NAL and the BEL has been found throughout Ontario and eastern Manitoba. In this study, we first characterized the functional differentiation in the cytochrome‐b (cytB) gene by identifying nonsynonymous changes. Second, the caribou lineages were used as a direct means to assess site‐specific parallel changes among lineages. There was greater functional diversity within the NAL despite the BEL having greater neutral diversity. The patterns of amino acid substitutions occurring within different lineages supported the parallel evolution of cytB amino acid substitutions suggesting different selective pressures among lineages. This study highlights the independent evolution of identical amino acid substitutions within a wide‐ranging mammal species that have diversified from different ancestral haplogroups and where ecological niches can invoke parallel evolution.
2D Materials‐based Platforms for Electroanalysis Applications
Authors: Alarcon‐Angeles Georgina , Palomar‐Pardavé Manuel , Merkoçi Arben
Published: May 2018

A new class of nanomaterials called “2D materials” (2DMs) is attracting recently the electrochemical sensing field due to the unique physicochemical properties associated to their chemical structure, formed by ultra‐thin layers. In this review, we summarize the recent advances in the electroanalysis area using 2DMs giving first a brief overview on the structure, synthesis and properties of these materials followed by the analysis of their advantages while used in the development of electrochemical sensors.
Differential micronucleus frequency in isogenic human cells deficient in DNA repair pathways is a valuable indicator for evaluating genotoxic agents and their genotoxic mechanisms
Authors: Saha Liton Kumar , Kim Sujin , Kang Habyeong , Akter Salma , Choi Kyungho , Sakuma Tetsushi , Yamamoto Takashi , Sasanuma Hiroyuki , Hirota Kouji , Nakamura Jun , Honma Masamitsu , Takeda Shunichi , Dertinger S.
Published: May 2018

The micronucleus (MN) test has become an attractive tool both for evaluating the genotoxicity of test chemicals because of its ability to detect clastogenic and aneugenic events and for its convenience. As the MN assay has been mostly performed using only DNA repair‐proficient mammalian cells, we believed that the comparison of the MN frequency between DNA repair‐proficient and ‐deficient human cells may be an excellent indicator for detecting the genotoxic potential of test chemicals and for understanding their mode of action. To address this issue, the following five genes encoding DNA‐damage‐response (DDR) factors were disrupted in the TK6 B cell line, a human cell line widely used for the MN test: FANCD2, DNA polymerase ζ (REV3), XRCC1, RAD54, and/or LIG4. Using these isogenic TK6 cell lines, the MN test was conducted for four widely‐used DNA‐damaging agents: methyl methanesulfonate (MMS), hydrogen peroxide (H2O2), γ‐rays, and mitomycin C (MMC). The frequency of micronuclei in the double strand break repair‐deficient RAD54−/−/LIG4−/− cells after exposure to γ‐rays, H2O2, MMS and MMC was 6.2‐7.5 times higher than that of parental wild‐type TK6 cells. The percentages of cells exhibiting micronuclei in the base excision repair‐ and single strand break repair‐deficient XRCC1−/− cells after exposure to H2O2, MMC and MMS were all ∼5 times higher than those of wild‐type cells. In summary, a supplementary MN assay using the combination of RAD54−/−/LIG4−/−, XRCC1−/− and wild‐type TK6 cells is a promising method for detecting the genotoxic potential of test chemicals and their mode of action. Environ. Mol. Mutagen., 2018. © 2018 Wiley Periodicals, Inc.
Effect of different concentrations of pulverized mesocarp of Citrus paradisi Macf. on the bromatological characteristics of spray‐dried lemon juice powder
Authors: Alcantara Marte Yanilka , Alcantara Marte Yulisa , Tejada Andrea Escotto , Ros Berruezo Gaspar
Published: May 2018

The aim of this research was to evaluate the effect of different concentrations of pulverized mesocarp of Citrus paradisi Macf. as a drying aid on the bromatological characteristics and yield of spray‐dried lemon juice powder. Five concentrations of grapefruit mesocarp encapsulant (0.4, 0.8, 1.2, 1.6, and 2.0% (w / w)) and maltodextrin DE 10 (1.2%, w / w) were evaluated as encapsulant agents. The highest yield (46.76%) was obtained with 1.2% of grapefruit encapsulant. Water activity and ash content were inversely proportional to the added encapsulant concentration. The highest moisture value was obtained with 0.4% and the highest soluble solids with 2.0%. For all treatments, the pH level did not change, except at 0.4% (it was lower). The concentrations of the encapsulants significantly affected the evaluated characteristics, except for the proteins.
A Fullerene‐Substituted Pillar[5]arene for the Construction of a Photoactive Rotaxane
Authors: Meichsner Eric , Nierengarten Iwona , Holler Michel , Chessé Matthieu , Nierengarten Jean‐François
Published: May 2018

Transformation of a methylene group of the pillar[5]arene scaffold into a ketone has been achieved by treatment with N‐bromosuccinimide followed by hydrolysis of the bromide intermediate and oxidation of the resulting secondary benzylic alcohol with BaMnO4. Condensation of the resulting macrocycle including a ketone function with p‐toluenesulfonyl hydrazide followed by reaction of the corresponding tosylhydrazone with C60 under modified Bamford–Stevens conditions gave a fulleropillar[5]arene derivative. This building block has been used to prepare a rotaxane. The resulting molecule combining the fullerene‐functionalized macrocycle with an axle bearing a porphyrin stopper is a photoactive molecular device in which the porphyrin emission is efficiently quenched by the fullerene moiety.
Performance‐based rewards and innovative behaviors
Authors: Sanders Karin , Jorgensen Frances , Shipton Helen , Van Rossenberg Yvonne , Cunha Rita , Li Xiaobei , Rodrigues Ricardo , Wong Sut I. , Dysvik Anders
Published: May 2018

This study investigates the effects of two internal factors, performance‐based rewards and employee perceptions of human resource (HR) strength, and one external factor, country‐level uncertainty avoidance, on employee innovative behaviors. Drawing on situational strength theory, we first hypothesize performance‐based rewards will positively relate to innovative behaviors, and second, this relationship is stronger when employees understand the wider Human Resource Management (HRM) system as intended by management, referred to as HR strength. Finally, we assess the effect of uncertainty avoidance on the relationship between performance‐based rewards and innovative behaviors. Three‐level data from 1,598 employees and 186 managers in 29 organizations across 10 countries showed both employee perceptions of HR strength and uncertainty avoidance of a country that differentially influence the relationship between performance‐based rewards and innovative behaviors. However, a significant relationship between performance‐based rewards and innovative behaviors was not found. This study offers novel insights into how organizations can use internal factors in a systematic manner to promote innovative behaviors in their workplace, and highlights the limitations of sustaining innovative behaviors in countries characterized by high levels of uncertainty avoidance.
Specifying the Dimensions of Aquatic Life Benchmark Values in Clear, Complete, and Justified Problem Formulations
Authors: Suter Glenn
Published: May 2018

Nations that develop water quality benchmark values have relied primarily on standard data and methods. However, experience with chemicals such as Se, ammonia, and tributyltin has shown that standard methods do not adequately address some taxa, modes of exposure, and effects. Development of benchmark values that are protective requires an explicit description of the issues, a problem formulation. In particular, the assessment endpoints and other dimensions should be specified for each chemical so that the necessary data will be obtained and appropriate analyses will be performed. Assessment endpoints specify the entity and attribute to be protected. In addition, the level of protection, including the magnitude of effect and the proportion effected, is specified. Magnitude and proportion are included because they are used to calculate the benchmark concentration. If uncertainty is considered in the benchmark, the proportion of the uncertainty distribution that is protected should be specified. Because effects are related to the duration of exposure and time for recovery, temporal dimensions should be specified. Clearly described exposure metrics are also needed because the relevant exposure parameter is not always total aqueous concentration. Finally, the benchmark may be applicable to particular geographic or climatological areas, water chemistries, taxa, or habitat types. Considering and justifying all the dimensions is likely to result in protective and more easily communicated benchmarks. Integr Environ Assess Manag 2018;14:631–638. Published 2018. This article is a US Government work and is in the public domain in the USA.

Key Points

Benchmark values for aquatic life are based on standard methods. Problem formulation provides an opportunity to identify conditions that make the standard method unsuitable. Problem formulation can be more effective if each of the dimensions of a benchmark value is formally characterized by weighing available evidence. The dimensions relate to the assessment endpoint, the level of protection, temporal dimensions, exposure metrics, and limits of applicability.
Comparison of materno‐fetal predictors and short‐term outcomes between early and late onset pre‐eclampsia in the low‐income setting of Douala, Cameroon
Authors: Nguefack Charlotte T. , Ako Mangwi A. , Dzudie Anastase T. , Nana Théophile N. , Tolefack Paul N. , Mboudou Emile
Published: May 2018

Objective

To describe and compare materno‐fetal predictors and short‐term outcomes of early onset pre‐eclampsia (EOPE) and late onset pre‐eclampsia (LOPE) in Douala, Cameroon.

Methods

The present prospective hospital‐based cross‐sectional study included women with pre‐eclampsia attending obstetric units at four hospitals in Douala between December 1, 2016, and April 30, 2017. To determine maternal predictors, sociodemographic and medical data were recorded using a pretested questionnaire. Pregnancy outcomes, and maternal and fetal adverse events were recorded. Univariate and multivariate logistic regression analyses were used to examine associations.

Results

Of 170 participants, 58 (34.1%) had EOPE and 112 (65.9%) had LOPE. EOPE was associated with higher incidences of chronic hypertension (P=0.027) and history of pre‐eclampsia (P=0.003) compared with LOPE. Higher incidences of nulliparity and a different partner from prior pregnancy (P=0.024) were associated with LOPE. Women with EOPE had higher odds of acute kidney injury (odds ratio [OR] 6.67, 95% confidence interval [CI] 1.73–25.73) and HELLP (hemolysis, elevated liver enzyme, low platelets) syndrome (OR 10.47, 95% CI 1.19–91.9), and lower odds of deliveries without perinatal adverse events (OR 0.19, 95% CI 0.09–0.38), compared with patients with LOPE.

Conclusion

In the low‐income setting of Douala, there was a higher rate of LOPE than EOPE. Factors associated with EOPE and LOPE varied, and outcomes were worse for women with EOPE.