bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐resolution probing of inner core structure with seismic interferometry
Authors: Huang Hsin‐Hua , Lin Fan‐Chi , Tsai Victor C. , Koper Keith D.
Published: December 2015

Increasing complexity of Earth's inner core has been revealed in recent decades as the global distribution of seismic stations has improved. The uneven distribution of earthquakes, however, still causes a biased geographical sampling of the inner core. Recent developments in seismic interferometry, which allow for the retrieval of core‐sensitive body waves propagating between two receivers, can significantly improve ray path coverage of the inner core. In this study, we apply such earthquake coda interferometry to 1846 USArray stations deployed across the U.S. from 2004 through 2013. Clear inner core phases PKIKP2 and PKIIKP2 are observed across the entire array. Spatial analysis of the differential travel time residuals between the two phases reveals significant short‐wavelength variation and implies the existence of strong structural variability in the deep Earth. A linear N‐S trending anomaly across the middle of the U.S. may reflect an asymmetric quasi‐hemispherical structure deep within the inner core with boundaries of 99°W and 88°E.
Double crests of peak height in the equatorial ionospheric F2 layer observed by COSMIC
Authors: Luan Xiaoli , Lei Jiuhou , Dou Xiankang , Dang Tong
Published: December 2015

For the first time, we report daytime double crests of peak height (hmF2) in the F2 layer based on the Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) observations during 2007–2014. Evident double crests of hmF2 occurred at around ±10° geomagnetic latitude with a trough over the magnetic equator at low solar activity and at March equinox. This phenomenon is referred to as an equatorial height anomaly (EHA) of the ionospheric F2 layer. The double crests became less obvious at September equinox and disappeared at solstices. At solstices only one crest was observed in the summer hemisphere, which is probably associated with transequatorial neutral winds. In addition, the double EHA crests generally take place during 10:00–14:00 local times. Our results indicate that the EHA favors the conditions of strong vertical plasma drifts and weak transequatorial neutral winds during low solar activity. The EHA feature is reproduced by the Thermosphere Ionosphere Electrodynamics Global Circulation Model at March equinox and low solar activity.
Methane emissions from pan‐Arctic lakes during the 21st century: An analysis with process‐based models of lake evolution and biogeochemistry
Authors: Tan Zeli , Zhuang Qianlai
Published: December 2015

The importance of methane emissions from pan‐Arctic lakes in the global carbon cycle has been suggested by recent studies. These studies indicated that climate change influences this methane source mainly in two ways: the warming of lake sediments and the evolution of thermokarst lakes. Few studies have been conducted to quantify the two impacts together in a unified modeling framework. Here we adapt a region‐specific lake evolution model to the pan‐Arctic scale and couple it with a lake methane biogeochemical model to quantify the change of this freshwater methane source in the 21st century. Our simulations show that the extent of thaw lakes will increase throughout the 21st century in the northern lowlands of the pan‐Arctic where the reworking of epigenetic ice in drained lake basins will continue. The projected methane emissions by 2100 are 28.3 ± 4.5 Tg CH4 yr−1 under a low warming scenario (Representative Concentration Pathways (RCPs) 2.6) and 32.7 ± 5.2 Tg CH4 yr−1 under a high warming scenario (RCP 8.5), which are about 2.5 and 2.9 times the simulated present‐day emissions. Most of the emitted methane originates from nonpermafrost carbon stock. For permafrost carbon, the methanogenesis will mineralize a cumulative amount of 3.4 ± 0.8 Pg C under RCP 2.6 and 3.9 ± 0.9 Pg C under RCP 8.5 from 2006 to 2099. The projected emissions could increase atmospheric methane concentrations by 55.0–69.3 ppb. This study further indicates that the warming of lake sediments dominates the increase of methane emissions from pan‐Arctic lakes in the future.
Natural Hematite for Next‐Generation Solid Oxide Fuel Cells
Authors: Wu Yan , Xia Chen , Zhang Wei , Yang Xiang , Bao Zheng Yu , Li Jiao Jun , Zhu Bin
Published: December 2015

Natural hematite ore is used as a novel electrolyte material for advanced solid oxide fuel cells (SOFCs). This hematite‐based system exhibits a maximum power density of 225 mW cm−2 at 600 °C and reaches 467 mW cm−2 when the hematite is mixed with perovskite‐structured La0.6Sr0.4Co0.2Fe0.8O3–δ. These results demonstrate that natural materials for next‐generation SOFCs can influence the multiutilization of natural resources, thereby affecting the environment and energy sustainability.
Activation of Oxygen‐Stabilized Sulfur for Li and Na Batteries
Authors: Luo Chao , Zhu Yujie , Borodin Oleg , Gao Tao , Fan Xiulin , Xu Yunhua , Xu Kang , Wang Chunsheng
Published: December 2015

The sulfur‐based cathode materials suffer severely from poor cycling stability and low utilization, incurred by their stepwise reaction mechanism that generates polysulfide intermediates and the subsequent irreversible losses. In this work, those issues are significantly relieved by entrapping sulfur species in carbon host rich in oxygen functionalities. Sulfur species in such C/S composite are highly stabilized by their interaction with oxygen, and can deliver a reversible capacity of 508 mAh/(g of S) for 2000 cycles when coupled with Li, representing the best cycling stability up to date. More interestingly, extra capacity can be accessed by simply prelithiating the oxygen‐stabilized C/S composites down to 0.6 V for a few cycles, which enables a high capacity of 1621 mAh/(g of S) that eventually stabilizes at 820 mAh/(g of S) for 600 cycles. The mechanism for this electrochemical activation process is investigated with both spectroscopic and electrochemical techniques, which reveal that the inactive sulfur bonded to oxygen is liberated in the initial deep lithiation precycles and becomes electrochemically active. The oxygen‐stabilized sulfur can also be coupled with Na anode to form Na/S cell, confirming that the formation of S−O interaction in C/S composite generates promising sulfur‐based cathode materials for Li–S and Na–S batteries.
Facile Solid‐State Growth of 3D Well‐Interconnected Nitrogen‐Rich Carbon Nanotube–Graphene Hybrid Architectures for Lithium–Sulfur Batteries
Authors: Ding Yuan‐Li , Kopold Peter , Hahn Kersten , van Aken Peter A. , Maier Joachim , Yu Yan
Published: December 2015

Constructing 3D carbon structures built from carbon nanotubes (CNTs) and graphene has been considered as an effective approach to achieve superior properties in energy conversion and storage because of the synergistic combination of the advantages of each building block. Herein, a facile solid‐state growth strategy is reported for the first time to fabricate highly nitrogen doped CNT–graphene 3D nanostructures without the necessity to use chemical vapor deposition. As cathode hosts for lithium–sulfur batteries, the hybrid architectures exhibit reversible capacities of 1314 and 922 mAh g−1 at 0.2 and 1 C, respectively, and a capacity retention of 97% after 200 cycles at a high rate of 2 C, revealing their great potential for energy storage application.
Synthesis of Chiral Polyethers Containing Imidazolidinone Repeating Units and Application as Catalyst in Asymmetric Diels–Alder Reaction
Authors: Itsuno Shinichi , Oonami Tatsuaki , Takenaka Nagisa , Haraguchi Naoki
Published: December 2015

In this study, enantiopure imidazolidinones containing two hydroxyphenyl groups were synthesized, and the Williamson synthesis of the chiral bisphenols thus prepared with dihalides afforded polyethers containing chiral imidazolidinone repeating units. These chiral imidazolidinone polyethers exhibited excellent catalytic activity in the asymmetric Diels–Alder reaction. With the use of these polymeric catalysts, enantioselectivities up to 99% were obtained, higher than those obtained by the corresponding monomeric imidazolidinone catalyst in homogeneous solution. The polymeric catalysts were found to be insoluble in commonly used organic solvents, and they could be repeatedly used without the loss of activity.

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Organocatalyzed Reduction of Tertiary Phosphine Oxides
Authors: Schirmer Marie‐Luis , Jopp Stefan , Holz Jens , Spannenberg Anke , Werner Thomas
Published: December 2015

A novel selective catalytic reduction method of tertiary phosphine oxides to the corresponding phosphines has been developed. Notably, the reaction proceeds smoothly with low catalyst loadings of 1–5 mol% even at low temperature (70 °C). Under the optimized conditions various phosphine oxides could be selectively reduced and the desired phosphines were usually obtained in excellent yields above 90%. Furthermore, we have developed a one‐pot reaction sequence for the preparation of valuable phosphine⋅borane adducts. Simple addition of BH3⋅THF subsequent to the reduction step gave the desired adducts in yields up to 99%.

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Synthesis of 4‐Aryl‐2‐Quinolones via Copper‐Catalyzed Hydroarylation of (o‐Aminophenyl)propiolates with Arylboronates
Authors: Murayama Tsukasa , Shibuya Masatoshi , Yamamoto Yoshihiko
Published: December 2015

4‐Aryl‐2(1H)‐quinolones were efficiently synthesized via copper‐catalyzed hydroarylation of (o‐aminophenyl)propiolates with arylboronic acid neopentyl glycol esters. The substrate propiolates were prepared from the corresponding silylalkynes with carbon dioxide by Kondo’s carboxylation method using N,N‐dimethylformamide as a solvent. Hydroarylation was performed in the presence of 3 mol% copper(II) acetate in methanol at 28 °C for 12 h and subsequent deprotection using trifluoromethanesulfonic acid (3.0 equiv.) at 65 °C for 2 h in the same pot to afford the desired 4‐aryl‐2(1H)‐quinolones in 39–89% yields.

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(040)‐Crystal Facet Engineering of BiVO4 Plate Photoanodes for Solar Fuel Production
Authors: Kim Chang Woo , Son Young Seok , Kang Myung Jong , Kim Do Yoon , Kang Young Soo
Published: December 2015

A (040)‐crystal facet engineered BiVO4 ((040)‐BVO) photoanode is investigated for solar fuel production. The (040)‐BVO photoanode is favorable for improved charge carrier mobility and high photocatalytic active sites for solar light energy conversion. This crystal facet design of the (040)‐BVO photoanode leads to an increase in the energy conversion efficiency for solar fuel production and an enhancement of the oxygen evolution rate. The photocurrent density of the (040)‐BVO photoanode is determined to be 0.94 mA cm−2 under AM 1.5 G illumination and produces 42.1% of the absorbed photon‐to‐current conversion efficiency at 1.23 V (vs RHE, reversible hydrogen electrode). The enhanced charge separation efficiency and improved charge injection efficiency driven by (040) facet can produce hydrogen with 0.02 mmol h−1 at 1.23 V. The correlation between the (040)‐BVO photoanode and the solar fuel production is investigated. The results provide a promising approach for the development of solar fuel production using a BiVO4 photoanode.
MORC2 mutations cause axonal Charcot–Marie–Tooth disease with pyramidal signs
Authors: Albulym Obaid M. , Kennerson Marina L. , Harms Matthew B. , Drew Alexander P. , Siddell Anna H. , Auer‐Grumbach Michaela , Pestronk Alan , Connolly Anne , Baloh Robert H. , Zuchner Stephan , Reddel Stephen W. , Nicholson Garth A.
Published: December 2015

Objective

To use linkage analysis and whole exome sequencing to identify the genetic mutation in a multigenerational Australian family with Charcot–Marie–Tooth disease type 2 (CMT2) and pyramidal signs.

Methods

Genome‐wide linkage analysis was performed to map the locus. Whole exome sequencing was undertaken on selected individuals (3 affected, 1 normal), and segregation analysis and mutation screening were carried out using high‐resolution melt analysis. The GEM.app database was queried to identify additional families with mutations.

Results

Significant linkage (2‐point LOD score ≥ +3) and haplotype analysis mapped a new locus for CMT2 and pyramidal signs to a 6.6Mb interval on chromosome 22q12.1–q12.3. Whole exome sequencing identified a novel mutation (p.R252W) in the microrchidia CW‐type zinc finger 2 (MORC2) gene mapping within the linkage region. The mutation fully segregated with the disease phenotype in the family. Screening additional families and querying unsolved CMT2 exomes, we identified the p.R252W mutation in 2 unrelated early onset CMT2 families and a second mutation p.E236G in 2 unrelated CMT2 families. Both the mutations occurred at highly conserved amino acid residues and were absent in the normal population.

Interpretation

We have identified a new locus in which MORC2 mutations are the likely pathogenic cause of CMT2 and pyramidal signs in these families. MORC2 encodes the human CW‐type zinc finger 2 protein, which is a chromatin modifier involved in the regulation of DNA repair as well as gene transcription. ANN NEUROL 2016;79:419–427
Energy‐lose induced unidirectional light propagation in porous alumina photonic crystal
Authors: Shang Guo Liang , Zhang Yao , Fei Guang Tao , Su Yan , De Zhang Li
Published: December 2015

Unidirectional light propagation phenomena are observed in the photonic crystal heterostructures based on anodic alumina membrane when the incident light illuminated from forward and backward directions. Transmittance / reflectance spectra measurements and theoretical calculations show that the origin of this kind of unbalanced reflection is ascribed to the energy loss induced by Rayleigh scattering. Importantly, unidirectional light propagation can be modulated over the whole visible light region by adjusting the combination of different photonic bandgap as well as the view angle. The as‐prepared heterostructures may provide potential applications in direction‐dependent photonic devices.
Entropisch bedingte Selektivität der Kettenspaltung oder: Wo Makromoleküle sich trennen
Authors: Pahnke Kai , Brandt Josef , Gryn'ova Ganna , Lin Ching Y. , Altintas Ozcan , Schmidt Friedrich G. , Lederer Albena , Coote Michelle L. , Barner‐Kowollik Christopher
Published: December 2015

Wir zeigen, dass bei Beibehaltung aller anderen Bedingungen ein Bindungsbruch in der Mitte von Molekülen entropisch wesentlich bevorzugter abläuft als ein Bindungsbruch in endständiger Position. Vielfältige experimentelle wie theoretische Ansätze wurden genutzt, um die Selektivität des Bindungsbruchs oder der Dissoziation von in der Mitte oder am Ende des Moleküls kovalent oder supramolekular verbundener Addukte zu untersuchen. Die weitreichenden Auswirkungen auf andere Bereiche der Chemie, wie beispielsweise Kettentransferreaktionen, Polymerdegradation oder die Addition von Kontrollagenzien, werden diskutiert. Die beobachteten Effekte, welche auf entropische Faktoren zurückzuführen sind, wurden auf der Grundlage von einfachen theoretischen Modellen vorhergesagt und mittels Hochtemperatur(HT)‐NMR‐Spektroskopie von selbstorganisierten, supramolekularen Diblocksystemen sowie temperaturabhängiger Größenausschlusschromatographie (TD SEC) von kovalent verknüpften Diels‐Alder‐Stufenwachstumspolymeren überprüft.
A Strategy to Promote the Electrocatalytic Activity of Spinels for Oxygen Reduction by Structure Reversal
Authors: Wu Guangping , Wang Jun , Ding Wei , Nie Yao , Li Li , Qi Xueqiang , Chen Siguo , Wei Zidong
Published: December 2015

The electrocatalytic performance of a spinel for the oxygen reduction reaction (ORR) can be significantly promoted by reversing its crystalline structure from the normal to the inverse. As the spinel structure reversed, the activation and cleavage of O−O bonds are accelerated owing to a dissimilarity effect of the distinct metal atoms co‐occupying octahedral sites. The CoIIFeIIICoIIIO4 spinel with the Fe and Co co‐occupying inverse structure exhibits an excellent ORR activity, which even exceeds that of the state‐of‐the‐art commercial Pt/C by 42 mV in alkaline medium.
Solution‐State 17O Quadrupole Central‐Transition NMR Spectroscopy in the Active Site of Tryptophan Synthase
Authors: Young Robert P. , Caulkins Bethany G. , Borchardt Dan , Bulloch Daryl N. , Larive Cynthia K. , Dunn Michael F. , Mueller Leonard J.
Published: December 2015

Oxygen is an essential participant in the acid–base chemistry that takes place within many enzyme active sites, yet has remained virtually silent as a probe in NMR spectroscopy. Here, we demonstrate the first use of solution‐state 17O quadrupole central‐transition NMR spectroscopy to characterize enzymatic intermediates under conditions of active catalysis. In the 143 kDa pyridoxal‐5′‐phosphate‐dependent enzyme tryptophan synthase, reactions of the α‐aminoacrylate intermediate with the nucleophiles indoline and 2‐aminophenol correlate with an upfield shift of the substrate carboxylate oxygen resonances. First principles calculations suggest that the increased shieldings for these quinonoid intermediates result from the net increase in the charge density of the substrate–cofactor π‐bonding network, particularly at the adjacent α‐carbon site.
Eine skalierbare Synthese sequenzdefinierter Makromoleküle mit hohen Ausbeuten
Authors: Solleder Susanne C. , Zengel Deniz , Wetzel Katharina S. , Meier Michael A. R.
Published: December 2015

Hier wird ein effizienter Ansatz zur Synthese eines sequenzdefinierten Decamers, dessen Selbstmetathese sowie die Charakterisierung der erhaltenen Makromoleküle beschrieben. Zu diesem Zweck wurde ein monogeschütztes AB‐Monomer synthetisiert und in einer Decamersynthese angewendet. Das erhaltene Decamer wurde durch iterative Verwendung der Passerini‐Dreikomponenten‐Reaktion (P‐3CR) mit anschließender Entschützung hergestellt und trägt zehn unterschiedliche, wählbare Seitenketten. Dieser hocheffiziente Syntheseansatz ermöglichte exzellente Ausbeuten sowie die Synthese von perfekt sequenzdefinierten Makromolekülen im Multigramm‐Maßstab. Am Ende der Synthese wurde ein Olefin als Seitenkette eingeführt, das eine Selbstmetathese‐Reaktion des Decamers und damit die Synthese eines sequenzdefinierten 20‐mers mit einem Molekulargewicht von 7046.40 g mol−1 ermöglichte. Die erhaltenen Oligomere wurden vollständig mittels NMR‐ und IR‐Spektroskopie, GPC, GPC‐ESI‐MS und Massenspektrometrie (FAB‐ und Orbitrap‐ESI‐MS) charakterisiert.
Temporal Control of Membrane Fusion through Photolabile PEGylation of Liposome Membranes
Authors: Kong Li , Askes Sven H. C. , Bonnet Sylvestre , Kros Alexander , Campbell Frederick
Published: December 2015

Membrane fusion results in the transport and mixing of (bio)molecules across otherwise impermeable barriers. In this communication, we describe the temporal control of targeted liposome–liposome membrane fusion and contents mixing using light as an external trigger. Our method relies on steric shielding and rapid, photoinduced deshielding of complementary fusogenic peptides tethered to opposing liposomal membranes. In an analogous approach, we were also able to demonstrate precise spatiotemporal control of liposome accumulation at cellular membranes in vitro.
Zuverlässiges Schalten von Diarylethenen in beide Richtungen mithilfe von sichtbarem Licht
Authors: Fredrich Sebastian , Göstl Robert , Herder Martin , Grubert Lutz , Hecht Stefan
Published: December 2015

Ein Diarylethen‐Photoschalter wurde kovalent einmal konjugiert und einmal nichtkonjugiert mit zwei Triplett‐Sensibilisatoreinheiten verknüpft, und die resultierenden Verbindungen wurden auf ihre photochromen Eigenschaften untersucht. Im Unterschied zum ursprünglichen Diarylethen (ohne Sensibilisator) und dem Derivat mit gesättigter Bindung zeigt der konjugierte Photoschalter eine ausgezeichnete Ermüdungsresistenz bedingt durch die Anregung mit sichtbarem Licht und den effektiven Triplettenergietransfer vom Biacetylterminus zum Diarylethenkern. Aufgrund der ausgedehnten π‐Konjugation und des Ringschlusses über den Triplettzustand lassen sich unsere Diarylethene mit sichtbarem Licht in beide Richtungen effektiv und robust schalten.
Corannulen komprimiert in einem molekularen Käfig
Authors: Schmidt Bernd M. , Osuga Takafumi , Sawada Tomohisa , Hoshino Manabu , Fujita Makoto
Published: December 2015

Durch Selbstorganisation erhaltene Käfigverbindungen können als molekulare Pressen genutzt werden. Die Komplexierung der schalenförmigen Verbindung Corannulen (C20H10) im Inneren des Käfigs erfolgt unter erheblicher Planarisierung des Gasts. Dies wird anhand von zwei Beispielen, der Einlagerung von Corannulen mit Naphthalindiimid und der Einlagerung von zwei Monobromcorannulenen, demonstriert. Die Änderung der Struktur wurde eindeutig durch Einkristallröntgenstrukturanalyse nachgewiesen.
B(C6F5)3: A Lewis Acid that Brings the Light to the Solid State
Authors: Hansmann Max M. , López‐Andarias Alicia , Rettenmeier Eva , Egler‐Lucas Carolina , Rominger Frank , Hashmi A. Stephen K. , Romero‐Nieto Carlos
Published: December 2015

The straightforward coordination of the Lewis acid B(C6F5)3 to classical, non‐emitting aldehydes results in solid‐state photoluminescence. Variation of the electronic properties of the carbonyl moieties lead to the modulation of the solid‐state emission colors, covering the entire visible spectrum with quantum yields up to 0.64. Steady‐state spectroscopy in combination with X‐ray diffraction analysis and DFT calculations confirm that intermolecular interactions between the Lewis adducts are responsible for the observed luminescence. Alteration of the latter interactions induces, moreover, remarkable solid‐state phenomena such as piezochromism. The versatility and simplicity of our approach facilitate the future development of solid‐state emitting materials.
A Scalable and High‐Yield Strategy for the Synthesis of Sequence‐Defined Macromolecules
Authors: Solleder Susanne C. , Zengel Deniz , Wetzel Katharina S. , Meier Michael A. R.
Published: December 2015

The efficient synthesis of a sequence‐defined decamer, its characterization, and its straightforward dimerization through self‐metathesis are described. For this purpose, a monoprotected AB monomer was designed and used to synthesize a decamer bearing ten different and selectable side chains by iterative Passerini three‐component reaction (P‐3CR) and subsequent deprotection. The highly efficient procedure provided excellent yields and allows for the multigram‐scale synthesis of such perfectly defined macromolecules. An olefin was introduced at the end of the synthesis, allowing the self‐metathesis reaction of the resulting decamer to provide a sequence‐defined 20‐mer with a molecular weight of 7046.40 g mol−1. The obtained oligomers were carefully characterized by NMR and IR spectroscopy, GPC and GPC coupled to ESI‐MS, and mass spectrometry (FAB and orbitrap ESI‐MS).
Switching Diarylethenes Reliably in Both Directions with Visible Light
Authors: Fredrich Sebastian , Göstl Robert , Herder Martin , Grubert Lutz , Hecht Stefan
Published: December 2015

A diarylethene photoswitch was covalently connected to two small triplet sensitizer moieties in a conjugated and nonconjugated fashion and the photochromic performance of the resulting compounds was investigated. In comparison with the parent diarylethene (without sensitizers) and one featuring saturated linkages, the conjugated photoswitch offers superior fatigue resistance upon visible‐light excitation due to effective triplet energy transfer from the biacetyl termini to the diarylethene core. Our design makes it possible to switch diarylethenes with visible light in both directions in a highly efficient and robust fashion based on extending π‐conjugation and by‐product‐free ring‐closure via the triplet manifold.
Rheological properties of thermoresponsive nanocomposite hydrogels
Authors: Hosseini Hossein , Tenhu Heikki , Hietala Sami
Published: December 2015

Highly elastic and robust nanocomposite hydrogels based on N‐isopropylacrylamide (NIPAM) and cationic (3‐acrylamidopropyl) trimethylammonium chloride (AMPTMA) were synthesized by photopolymerization. Nanoscopic clay, laponite XLS, was added in the gels during the synthesis. The effect of a hydrophobic salt, lithium bis(trifluoromethane) sulfonimide (LiNTf2), and clay content on the viscoelastic properties, swelling ratio, and stiffness of the nanocomposite hydrogels were investigated as a function of temperature. Synthetic clay served as a multifunctional cross‐linker, producing hydrogels with enhanced elastic properties. Anionic NTf2 binds to the cationic comonomer units and significantly affected the viscoelasticity and thermal properties. DSC measurements showed that the volume phase transition temperature and its enthalpy changed with the clay content and with introducing the cationic comonomer (AMPTMA) in the PNIPAM network. With the addition of either laponite XLS or the comonomer and 5 mM solution of LiNTf2, a fourfold and fivefold increase in elastic modulus was obtained, respectively, compared to that of the homopolymer PNIPAM hydrogel. With increasing the temperature from 20 to 45°C for the copolymer gel with 10% AMPTMA in 5 mM LiNTf2, the elastic modulus grew 15 times larger. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43123.
Carbonized electrospun polyacrylonitrile nanofibers as highly sensitive sensors in structural health monitoring of composite structures
Authors: Alarifi Ibrahim M , Alharbi Abdulaziz , Khan WseeemS , Asmatulu Ramazan
Published: December 2015

Electrospun polyacrylonitrile (PAN) nanofibers were stabilized at 280°C for 1 h in an ambient condition, and then carbonized at 850°C in inert argon gas for additional 1 h in order to fabricate highly pure carbonous nanofibers for the development of highly sensitive sensors in structural health monitoring (SHM) of composite aircraft and wind turbines. This study manifests the real‐time strain response of the carbonized PAN nanofibers under various tensile loadings. The prepared carbon nanofibers were placed on top of the carbon fiber pre‐preg composite as a single layer. Using a hand lay‐up method, and then co‐cured with the pre‐preg composites in a vacuum oven following the curing cycle of the composite. The electric wires were connected to the top surface of the composite panels where the cohesively bonded conductive nanofibers were placed prior to the tensile and compression loadings in the grips of the tensile unit. The test results clearly showed that the carbonized electrospun PAN nanofibers on the carbon fiber composites were remarkably performed well. Even the small strain rates (e.g., 0.020% strain) on the composite panels were easily detected through voltage and resistance changes of the panels. The change in voltage can be mainly attributed to the breakage/deformation of the conductive network of the carbonized PAN nanofibers under the loadings. The primary goal of the present study is to develop a cost‐effective, lightweight, and flexible strain sensor for the SHM of composite aircraft and wind turbines. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43235.
Prevalence of Cervical Enamel Projection and Its Impact on Furcation Involvement in Mandibular Molars: A Cone‐Beam Computed Tomography Study in Koreans
Authors: Lim Hyun‐Chang , Jeon Seok‐Kyun , Cha Jae‐Kook , Lee Jung‐Seok , Choi Seong‐Ho , Jung Ui‐Won
Published: December 2015

This study evaluated the prevalence of cervical enamel projections (CEPs) in mandibular molars, and analyzed the correlation between CEPs and furcation involvement (FI) based on cone‐beam computed tomography (CBCT) data in a Korean population. CBCT images obtained from March 2012 to August 2012 were analyzed. CEPs and FI on the buccal and lingual surface were classified in three‐dimensionally reconstructed images and cross‐sectional views, and the correlation between these two parameters was analyzed. In total, 982 teeth in 425 patients were analyzed. The overall prevalence rate of CEPs was 76% (71% and 27% on the buccal and lingual surfaces, respectively). Grade I CEPs were the most common, followed by CEPs of grades II and III. There was a statistically significant, but negligible correlation between the CEP grade and the degree of FI on the buccal and lingual surfaces. Within the limitations of this cross‐sectional study, a high prevalence of CEPs were found in a Korean population, but the role of CEPs in provoking FI appeared not to be decisive. Anat Rec, 299:379–384, 2016. © 2015 Wiley Periodicals, Inc.
A Bromo‐Functionalized Conjugated Polymer as a Cross‐Linkable Anode Interlayer of Polymer Solar Cells
Authors: Meng Bin , Xie Zhiyuan , Liu Jun , Wang Lixiang
Published: December 2015

A cross‐linkable conjugated polymer with bromo groups on the side chain has been developed and used as an anode interlayer to improve the active layer morphology and consequently enhance the device performance of polymer solar cells (PSCs). The polymer, PCDTBT‐Br, has cross‐linkable bromo groups attached to the side chain of a widely‐used donor polymer, poly[N‐9‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4,7‐di‐2‐thienyl‐2,1,3‐benzothiadiazole)] (PCDTBT). The pendant bromo groups do not significantly change the LUMO/HOMO energy levels and absorption spectrum of the PCDTBT polymer backbone. PDCTBT‐Br can crosslink under UV irradiation to give a robust film, which enables multilayer PSC device fabrication. Moreover, the much lower surface energy of PCDTBT‐Br (20.4 mJ m−2) compared to PEDOT:PSS (91.6 mJ m−2) is beneficial for achieving optimal active layer morphology. As a result, with PCDTBT:[6,6]‐phenyl‐C71 butyric acid methyl ester (PC71BM) as the active layer, the PSC device with PCDTBT‐Br as the underlying layer shows a power conversion efficiency (PCE) of 6.59 %, in comparison to a PCE of 5.86 % of the control device. The device performance enhancement is ascribed to the much improved phase separation with a fibrillar nanostructure in the active layer.
An Extremely Porous Hydrogen‐Bonded Framework Composed of d‐Penicillaminato CoIII2AuI3 Complex Anions and Aqua Cobalt(II) Cations: Formation and Stepwise Structural Transformation
Authors: Surinwong Sireenart , Yoshinari Nobuto , Yotnoi Bunlawee , Konno Takumi
Published: December 2015

A unique example of a hydrogen‐bonded ionic solid with a porosity of 80 %, [Co(H2O)6]3[Co2Au3(d‐pen‐N,S)6]2 (1; d‐H2pen=d‐penicillamine), composed of [Co(H2O)6]2+ cations and [Co2Au3(d‐pen‐N,S)6]3− anions, is reported. Solid 1 was kinetically produced and was then transformed stepwise into two more thermodynamically stable solids with lower porosities, [Co(H2O)4][Co(H2O)6]2[Co2Au3(d‐pen‐N,S)6]2 (2) and [Co(H2O)4]3[Co2Au3(d‐pen‐N,S)6]2 (3), through the coordination of the free carboxylate groups in [Co2Au3(d‐pen‐N,S)6]3− to CoII centers. Solids 1–3 were structurally characterized, and the selective adsorption of small molecules into their pores was investigated.
Unraveling the Aging Skein: Disentangling Sensory and Cognitive Predictors of Age‐related Differences in Decision Making
Authors: Del Missier Fabio , Hansson Patrik , Parker Andrew M. , Bruine de Bruin Wändi , Nilsson Lars‐Göran , Mäntylä Timo
Published: December 2015

Age‐related differences in sensory functioning, processing speed, and working memory have been identified as three significant predictors of the age‐related performance decline observed in complex cognitive tasks. Yet, the assessment of their relative predictive capacity and interrelations is still an open issue in decision making and cognitive aging research. Indeed, no previous investigation has examined the relationships of all these three predictors with decision making. In an individual‐differences study, we therefore disentangled the relative contribution of sensory functioning, processing speed, and working memory to the prediction of the age‐related decline in cognitively demanding judgment and decision‐making tasks. Structural equation modeling showed that the age‐related decline in working memory plays an important predictive role, even when controlling for sensory functioning, processing speed, and education. Implications for research on decision making and cognitive aging are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Advanced Paternal Age and Risk of Musculoskeletal Congenital Anomalies in Offspring
Authors: Urhoj Stine Kjaer , Mortensen Laust Hvas , Nybo Andersen Anne‐Marie
Published: December 2015

OBJECTIVE

Previous research suggests that advanced paternal age increases the risk of musculoskeletal congenital anomalies (CAs) in offspring, but findings are inconsistent. This study aims to investigate the risk of musculoskeletal CAs according to paternal age at birth in an unselected population covering cohort of children.

STUDY DESIGN

A register‐based prospective study of 1,605,885 children born in Denmark, 1978–2004, using information from record‐linked health and administrative registers. The association between paternal age and overall musculoskeletal CAs, limb anomalies, craniosynostosis, skeletal dysplasias, syndromic musculoskeletal CAs, and other musculoskeletal CAs were investigated by multiple logistic regression analysis.

RESULTS

For overall musculoskeletal CAs, a slightly higher risk per 10‐year increase in paternal age was found (odds ratio [OR] = 1.06 [95% CI: 1.01–1.11; where CI is confidence interval]). A 26% (95% CI: 2–56%) excess risk was found for fathers aged 50+ years compared to fathers aged 30–34 years. For syndromic musculoskeletal CAs, excess risks were found for fathers aged 40+ years, compared to fathers aged 30–34 years (40–44: OR = 1.38 [95% CI: 1.01–1.88], 45–49: OR = 1.45 [95% CI: 0.89–2.34], 50+: OR = 1.42 [95% CI: 0.73–2.79]). The risks in all other subgroups of musculoskeletal CAs were increased for fathers aged 50+ years.

CONCLUSIONS

A slightly higher risk for overall musculoskeletal CAs in offspring was found with increasing paternal age, mainly due to an excess risk of syndromic musculoskeletal CAs for fathers aged 40+ years. While associations between paternal age 50+ years and increased risk of all subtypes of musculoskeletal CAs were indicated, advanced paternal age likely plays a minor role in the etiology of these anomalies
Pelvic exenteration for advanced malignancy in elderly patients
Authors: Radwan R W , Evans M D , Davies M , Harris D A , Beynon J , Hatcher O , Bose P , Lucas M G , Featherstone J , Khot U , Chandrasekaran T V , Carr N D , Gwynne S , Drew P , Phan M D
Published: December 2015

Background

Pelvic exenteration is an aggressive surgical procedure reserved for highly selected patients. Surgery in the elderly is often associated with increased morbidity and mortality. The aim of this study was to review outcomes following exenteration for advanced pelvic malignancy in this subgroup of patients.

Methods

All patients aged 70 years and over who underwent pelvic exenteration between 1999 and 2014 were included in the study. This comprised all primary rectal, gynaecological and bladder tumours. The primary outcome measure was 5-year overall survival. Secondary endpoints were postoperative morbidity and 30-day mortality.

Results

A total of 94 patients were included, with a median age of 76 (range 70–90) years. There were 65 rectal, 20 gynaecological and nine bladder tumours. The administration of neoadjuvant therapy was significantly different among tumour types (P = 0·002). A total of 32 patients (34 per cent) developed postoperative complications, and there were six deaths (6 per cent) within 30 days of surgery. Median survival was 64 months for patients with rectal cancer, 30 months for those with gynaecological tumours and 15 months for those with bladder cancer. Five-year survival rates in these groups were 47, 31 and 22 per cent respectively (P = 0·023).

Conclusion

Given the possibility of long-term survival, pelvic exenteration should not be withheld on the grounds of advanced age alone.
Nanoparticles for Use in Enzyme Assays
Authors: Kim Young‐Pil , Kim Hak‐Sung
Published: December 2015

Nanoparticles (NPs) have created new ways to enhance the performance of classical biosensors in analytical sciences. NPs with unprecedented physiochemical properties can serve both as excellent carriers of bioreceptors and as signal enhancers, leading to improved assay platforms with high sensitivity and selectivity. Because enzymes play central roles in many cellular functions, specific and precise assays of their functions are of great significance in medical science and biotechnology. Here we review recent advances in NP‐based biosensors and their use in enzyme assays. With fast and specific responses to enzyme‐mediated reactions, NPs transduce and amplify the initial responses into various types of signals, such as electrochemical, optical and magnetic ones. Translation of their potential should lead to functionalized NPs finding wide applications in diagnostics, drug development and biotechnology.
Rapid NMR Assignments of Proteins by Using Optimized Combinatorial Selective Unlabeling
Authors: Dubey Abhinav , Kadumuri Rajashekar Varma , Jaipuria Garima , Vadrevu Ramakrishna , Atreya Hanudatta S.
Published: December 2015

A new approach for rapid resonance assignments in proteins based on amino acid selective unlabeling is presented. The method involves choosing a set of multiple amino acid types for selective unlabeling and identifying specific tripeptides surrounding the labeled residues from specific 2D NMR spectra in a combinatorial manner. The methodology directly yields sequence specific assignments, without requiring a contiguously stretch of amino acid residues to be linked, and is applicable to deuterated proteins. We show that a 2D [15N,1H] HSQC spectrum with two 2D spectra can result in ∼50 % assignments. The methodology was applied to two proteins: an intrinsically disordered protein (12 kDa) and the 29 kDa (268 residue) α‐subunit of Escherichia coli tryptophan synthase, which presents a challenging case with spectral overlaps and missing peaks. The method can augment existing approaches and will be useful for applications such as identifying active‐site residues involved in ligand binding, phosphorylation, or protein–protein interactions, even prior to complete resonance assignments.
Core–Shell Composites Based on Multiwalled Carbon Nanotubes and Cesium Tungsten Bronze to Realize Charge Transport Balance for Photocatalytic Water Oxidation
Authors: Zhao Yingqiang , Han Fengyun , Wang Qian , Cui Guan‐Wei , Shi Xi‐Feng , Xia Xin‐Yuan , Xie Junfeng , Li Yong , Tang Bo
Published: December 2015

Core–shell composite photocatalysts based on multiwalled carbon nanotubes (MWCNTs) and Cs2W3O10 are first synthesized by an ion‐directing method. Cs+ is preadsorbed on the surface of MWCNTs by electrostatic forces and directs the crystallization of Cs2W3O10 to form a uniform layer on the surface of the MWCNTs. This core–shell arrangement of a MWCNT@Cs2W3O10 composite photocatalyst with a 15 nm thick Cs2W3O10 layer allows the charge transport balance to be achieved in the photocatalytic water oxidation process and confers a high photoactivity. Other reference composite photocatalysts that deviate from this balance result in deteriorated photoactivity. The established synthetic method provides a new method for the design and synthesis of composite photocatalysts, and the realization of charge transport balance is helpful to understand the nature of the enhancement of photoactivity in photocatalytic processes.
Novel Bifunctional Zn–Sn Composite Oxide Catalyst for the Selective Synthesis of Glycerol Carbonate by Carbonylation of Glycerol with Urea
Authors: Manjunathan Pandian , Ravishankar Raman , Shanbhag Ganapati V.
Published: December 2015

A novel Zn–Sn composite oxide is reported as a solid bifunctional catalyst for glycerol carbonylation to give glycerol carbonate in high yields. It was prepared by coprecipitation, solid‐state and evaporation methods. Physico‐chemical properties of the catalysts were investigated by XRD, N2 sorption, temperature‐programmed desorption, SEM, and TEM techniques. Coprecipitation was found to be better than the other two methods for carbonylation of glycerol. Higher activity of the catalyst was attributed to a high amount of active sites. A series of Zn–Sn composite oxides with different metal contents and effect of calcination on glycerol carbonate synthesis were also studied. The correlation of activity with total active sites of the catalyst was obtained. Zn–Sn composite catalyst with Zn/Sn molar ratio=2:1 calcined at 600 °C exhibited 96.0 % glycerol conversion with 99.6 % selectivity towards glycerol carbonate under optimized reaction conditions. The catalyst was recycled four times with a marginal decrease in activity.
Functionalization of Carbon Materials by Reduction of Diazonium Cations Produced in Situ in a Brønstedt Acidic Ionic Liquid
Authors: Carvalho Padilha Janine , Noël Jean‐Marc , Bergamini Jean‐François , Rault‐Berthelot Joëlle , Lagrost Corinne
Published: December 2015

The imidazolium‐based acidic ionic liquid 1‐butyl‐3‐methylimidazolium hydrogensulfate, [BMIm][HSO4], is used for the grafting of carbon materials, allowing the nitrobenzene diazonium cations to be simply produced in situ. An appealing self‐limiting and self‐patching process occurs in this viscous ionic liquid. Even for low electrolysis charge consumption, the layers are particularly dense and compact at atomic force microscopy resolution. The grafting method is further extended to carbon nanotubes, following either an electrochemical or a chemical route. A bucky paste is easily obtained from [BMIm][HSO4] and carbon nanotubes that could coat a graphite electrode surface. This simple soft method allows: 1) in situ electrografting of carbon nanotubes in [BMIm][HSO4] and/or 2) easy‐to‐handle electrochemical characterizations of the functionalized carbon nanotubes. The covalent functionalization of single‐walled carbon nanotubes is further assessed by Raman spectroscopy.
Anodic Electrochromic Nickel Oxide Thin Films: Decay of Charge Density upon Extensive Electrochemical Cycling
Authors: Wen Rui‐Tao , Granqvist Claes G. , Niklasson Gunnar A.
Published: December 2015

Electrochromic (EC) Ni oxide thin films are a critical component in the smart windows. However, long‐term decay of the EC performance in aprotic electrolytes is persistent and poorly understood, and it is difficult to assess lifetimes of EC devices. Here we report on charge density decline upon electrochemical cycling. The charge density decay was modeled with a power law or, alternatively, a stretched exponential; both models describe a rapid drop of charge density during the first hundreds of cycles and a subsequent slower decline. The decay is independent of film composition and applied potential range as long as the upper limit of the potential is ≤4.4 V vs. Li/Li+. Our decay models are interpreted in terms of dispersive chemical reaction kinetics and point at ion diffusion as the rate‐limiting step. Power‐law exponents are consistent with diffusion. The results provide a framework for evaluating EC durability of Ni‐oxide‐based thin films and may be important for assessing the durability of EC devices.
Graphite‐Nanoplate‐Coated Bi2S3 Composite with High‐Volume Energy Density and Excellent Cycle Life for Room‐Temperature Sodium–Sulfide Batteries
Authors: Li Wei‐Jie , Han Chao , Chou Shu‐Lei , Wang Jia‐Zhao , Li Zhen , Kang Yong‐Mook , Liu Hua‐Kun , Dou Shi‐Xue
Published: December 2015

Graphite‐nanoplate‐coated Bi2S3 composite (Bi2S3@C) has been prepared by a simple, scalable, and energy‐efficient precipitation method combined with ball milling. The Bi2S3@C composite was used as the cathode material for sodium–sulfide batteries. It delivered an initial capacity of 550 mAh g−1 and high stable specific energy in the range of 275–300 Wh kg−1 at 0.1 C, with an enhanced capacity retention of 69 % over 100 cycles. The unique structure demonstrates superior cycling stability, with a capacity drop of 0.3 % per cycle over 100 cycles, compared with that of bare Bi2S3. The sodium storage mechanism of Bi2S3 was investigated based on ex situ X‐ray diffraction and scanning transmission electron microscopy.
Ruthenium‐Catalyzed Cycloisomerization of 2,2′‐Diethynyl‐ biphenyls Involving Cleavage of a Carbon–Carbon Triple Bond
Authors: Matsuda Takanori , Kato Kotaro , Goya Tsuyoshi , Shimada Shingo , Murakami Masahiro
Published: December 2015

A ruthenium complex catalyzes a new cycloisomerization reaction of 2,2′‐diethynylbiphenyls to form 9‐ethynylphenanthrenes, thereby cleaving the carbon–carbon triple bond of the original ethynyl group. A metal–vinylidene complex is generated from one of the two ethynyl groups, and its carbon–carbon double bond undergoes a [2+2] cycloaddition with the other ethynyl group to form a cyclobutene. The phenanthrene skeleton is constructed by the subsequent electrocyclic ring opening of the cyclobutene moiety.
A Boiling‐Water‐Stable, Tunable White‐Emitting Metal–Organic Framework from Soft‐Imprint Synthesis
Authors: He Jun , Huang Jian , He Yonghe , Cao Peng , Zeller Matthias , Hunter Allen D. , Xu Zhengtao
Published: December 2015

A new avenue for making porous frameworks has been developed by borrowing an idea from molecularly imprinted polymers (MIPs). In lieu of the small molecules commonly used as templates in MIPs, soft metal components, such as CuI, are used to orient the molecular linker and to leverage the formation of the network. Specifically, a linear dicarboxylate linker with thioether side groups reacted simultaneously with Ln3+ ions and CuI, leading to a bimetallic net featuring strong, chemically hard Eu3+–carboxylate links, as well as soft, thioether‐bound Cu2I2 clusters. The CuI block imparts water stability to the host; with the tunable luminescence from the lanthanide ions, this creates the first white‐emitting MOF that is stable in boiling water. The Cu2I2 block also readily reacts with H2S, and enables sensitive colorimetric detection while the host net remains intact.
Dividing Wall Column as Energy Saving Retrofit Technology
Authors: Jansen Helmut , Dejanović Igor , Rietfort Thomas , Olujić Žarko
Published: December 2015

The present paper shows that existing two‐ or three‐column sequences could be transformed in a cost‐effective way into a dividing wall column (DWC) to allow for energy saving equivalent to that achievable in new designs. This makes DWC an interesting retrofit option for process industries willing to achieve a substantial reduction in energy requirement and carbon dioxide emissions in existing plants. Additional benefit is reflected in the potential for increasing substantially the capacity of existing units in the most sustainable way.
Analytik rund ums Holi‐Pulver
Authors: Steff Henning , Schröder Thomas Philipp , Buse Susanne , Bär Lukas , Vogel Fiona , Heller Marvin , Sommer Katrin
Published: December 2015

Bei Holi‐Parties wird – in Anlehnung an ein hinduistisches Ritual – ein stärkehaltiges gefärbtes Effekt‐Pulver (Holi‐Pulver) in Menschenmassen geworfen. Die Feuerwehr warnt: Durch Funken, z.B. von Zigaretten, könnte es zur Staubexplosion kommen. Wichtige Einflussparameter, die das Explosionsverhalten von Stäuben bestimmen, sind die stoffliche Zusammensetzung von Stäuben, der Wassergehalt und die Feinheit. Diese Parameter werden an Holi‐Pulvern eines deutschen sowie eines indischen Anbieters untersucht. Der Parameter stoffliche Zusammensetzung erweist sich als zentral. Die Holi‐Pulver des indischen Anbieters bestehen zu über 90 % aus brennbarer (Mais‐)Stärke. Die Holi‐Pulver des deutschen Anbieters sind so ausbalanciert, dass sowohl Stärke als auch Inertstoffe enthalten sind. Mit Hilfe von Modell‐Stoffgemischen wird ermittelt, dass die Explosionsfähigkeit der Stoffgemische mit zunehmendem Inertstoffanteil deutlich herabgesetzt wird. Alle Zündversuche werden mit einer für Schule und Ausbildung entwickelten Low‐Cost‐Hartmann‐Apparatur durchgeführt.