bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study on Processing, Characterization and Erosion Wear Response of Linz–Donawitz Slag Filled Epoxy Composites
Authors: Pati Pravat Ranjan , Satapathy Alok
Published: February 2015

This paper reports a study on erosion response of epoxy composites filled with micro‐sized Linz–Donawitz (LD) slag particles. LD slag is a major solid waste generated in huge quantities during steel making. It comes from slag formers such as burned lime/dolomite and from oxidizing of silica, iron etc. while refining the iron into steel in the LD furnace. Although a number of ways for its utilization have been suggested in the past, its potential as a filler material in polymeric matrices has not yet been explored. In this work, composites of five different compositions (0, 7.5, 15, 22.5 and 30 wt% of LD slag reinforced in epoxy resin) are prepared by a simple hand layup technique. The composites are characterized in regard to their density, porosity, micro‐hardness and strength properties. Erosion trials (ASTM G 76) are conducted on the composite samples following a well‐planned experimental schedule based on Taguchi's design of experiments. The study reveals that the impact velocity and LD slag content in the composites are the most significant among various factors that influence the wear rate. This work shows that LD slag, in spite of being a waste, possesses fairly good filler characteristics as it modifies the properties and improves the erosion resistance of the polymeric resin.
Matrix Organization and Merit Factor Evaluation as a Method to Address the Challenge of Finding a Polymer Material for Roll Coated Polymer Solar Cells
Authors: Bundgaard Eva , Livi Francesco , Hagemann Ole , Carlé Jon E. , Helgesen Martin , Heckler Ilona M. , Zawacka Natalia K. , Angmo Dechan , Larsen‐Olsen Thue T. , dos Reis Benatto Gisele A. , Roth Bérenger , Madsen Morten V. , Andersson Mats R. , Jørgensen Mikkel , Søndergaard Roar R. , Krebs Frederik C.
Published: February 2015

The results presented demonstrate how the screening of 104 light‐absorbing low band gap polymers for suitability in roll coated polymer solar cells can be accomplished through rational synthesis according to a matrix where 8 donor and 13 acceptor units are organized in rows and columns. Synthesis of all the polymers corresponding to all combinations of donor and acceptor units is followed by characterization of all the materials with respect to molecular weight, electrochemical energy levels, band gaps, photochemical stability, carrier mobility, and photovoltaic parameters. The photovoltaic evaluation is carried out with specific reference to scalable manufacture, which includes large area (1 cm2), stable inverted device architecture, an indium‐tin‐oxide‐free fully printed flexible front electrode with ZnO/PEDOT:PSS (poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate), and a printed silver comb back electrode structure. The matrix organization enables fast identification of active layer materials according to a weighted merit factor that includes more than simply the power conversion efficiency and is used as a method to identify the lead candidates. Based on several characteristics included in the merit factor, it is found that 13 out of the 104 synthesized polymers outperformed poly(3‐hexylthiophene) under the chosen processing conditions and thus can be suitable for further development.
Nanothermite auf Sulfat‐Basis: ein weites Feld metastabiler Kompositmaterialien
Authors: Comet Marc , Vidick Geoffrey , Schnell Fabien , Suma Yves , Baps Bernard , Spitzer Denis
Published: February 2015

In dieser Arbeit wurden Metallsulfate (Me=Ba, Bi, Ca, Cu, Mg, Mn, Na, Zn, Zr) als Oxidationsmittel in reaktiven Mischungen mit Al‐Nanopulvern umgesetzt. Die resultierenden neuen Arten dieser Nanothermite zeigen im Vergleich zu konventionellen Al/Metalloxid‐Mischungen (1.5–4.8 kJ g−1) besonders hohe Reaktionswärmen, (4–6 kJ g−1), verbunden mit attraktiven Zersetzungsgeschwindigkeiten innerhalb einer gemeinsamen Größenordnung (200–840 m s−1 gegenüber 100–2500 m s−1 für die konventionellen Mischungen). Die dargestellten Gemische erwiesen sich als extrem unempfindlich gegenüber Reibung, was eine einfache und sichere Handhabung der Materialien ermöglicht. Das Hydratwasser des Sulfats erhöht die Reaktionswärme und beeinflusst signifikant die Empfindlichkeit gegenüber elektrostatischer Entladung und Stößen (Schlagempfindlichkeit). Die Reaktion von Al mit Wasser ist dabei leichter zu initiieren als die mit Sulfat. Dies führt zu zwei möglichen Zersetzungsmodi für Proben, die einer offenen Flamme ausgesetzt sind. Pyrotechnische Eigenschaften der Sulfate konnten auch für andere Schwefel‐Sauerstoff‐Verbindungen (SO32−, S2O32−, S2O82−) gezeigt werden. Dies öffnet ein weites Feld an neuen, metastabilen Kompositmaterialien.
Microfluidic Synthesis of Rigid Nanovesicles for Hydrophilic Reagents Delivery
Authors: Zhang Lu , Feng Qiang , Wang Jiuling , Sun Jiashu , Shi Xinghua , Jiang Xingyu
Published: February 2015

We present a hollow‐structured rigid nanovesicle (RNV) fabricated by a multi‐stage microfluidic chip in one step, to effectively entrap various hydrophilic reagents inside, without complicated synthesis, extensive use of emulsifiers and stabilizers, and laborious purification procedures. The RNV contains a hollow water core, a rigid poly (lactic‐co‐glycolic acid) (PLGA) shell, and an outermost lipid layer. The formation mechanism of the RNV is investigated by dissipative particle dynamics (DPD) simulations. The entrapment efficiency of hydrophilic reagents such as calcein, rhodamine B and siRNA inside the hollow water core of RNV is ≈90 %. In comparison with the combination of free Dox and siRNA, RNV that co‐encapsulate siRNA and doxorubicin (Dox) reveals a significantly enhanced anti‐tumor effect for a multi‐drug resistant tumor model.
Deconstructing Covalent Organocatalysis
Authors: Holland Mareike C. , Gilmour Ryan
Published: February 2015

Modern organocatalysis has rapidly evolved into an essential component of contemporary organic synthesis. One of the most distinctive aspects of organocatalytic processes is the biomimetic nature in which the catalyst engages the substrate, often forming covalently bound intermediates in a manner reminiscent of enzyme catalysis. Indeed, the process of intramolecularization is often accompanied by a conformational change of the catalyst scaffold, further accentuating this analogy with biological systems. The isolation and study of these catalytic intermediates facilitate the rapid generation of conformation and reactivity profiles to assist in organocatalytic reaction development and/or clarify reaction outcomes. Emulating the formative advances that have derived from studying reaction intermediates in mechanistic organometallic and enzymatic catalysis, the deconstruction of covalently bound organocatalysis intermediates is gaining momentum as a design strategy.
Biomass‐Derived Carbon Quantum Dot Sensitizers for Solid‐State Nanostructured Solar Cells
Authors: Briscoe Joe , Marinovic Adam , Sevilla Marta , Dunn Steve , Titirici Magdalena
Published: February 2015

New hybrid materials consisting of ZnO nanorods sensitized with three different biomass‐derived carbon quantum dots (CQDs) were synthesized, characterized, and used for the first time to build solid‐state nanostructured solar cells. The performance of the devices was dependent on the functional groups found on the CQDs. The highest efficiency was obtained using a layer‐by‐layer coating of two different types of CQDs.
Encapsulation of Functional Organic Compounds in Nanoglass for Optically Anisotropic Coatings
Authors: Stöter Matthias , Biersack Bernhard , Rosenfeldt Sabine , Leitl Markus J. , Kalo Hussein , Schobert Rainer , Yersin Hartmut , Ozin Geoffrey A. , Förster Stephan , Breu Josef
Published: February 2015

A novel approach is presented for the encapsulation of organic functional molecules between two sheets of 1 nm thin silicate layers, which like glass are transparent and chemically stable. An ordered heterostructure with organic interlayers strictly alternating with osmotically swelling sodium interlayers can be spontaneously delaminated into double stacks with the organic interlayers sandwiched between two silicate layers. The double stacks show high aspect ratios of >1000 (typical lateral extension 5000 nm, thickness 4.5 nm). This newly developed technique can be used to mask hydrophobic functional molecules and render them completely dispersible in water. The combination of the structural anisotropy of the silicate layers and a preferred orientation of molecules confined in the interlayer space allows polymer nanocomposite films to be cast with a well‐defined orientation of the encapsulated molecules, thus rendering the optical properties of the nanocoatings anisotropic.
Spatial genetic structure of dusky dolphin,Lagenorhynchus obscurus, along the argentine coast: preserve what scale?
Authors: Loizaga de Castro Rocio , Dans Silvana L. , Crespo Enrique A.
Published: February 2015

The dusky dolphin (Lagenorhynchus obscurus) represents one of the most abundant species of small cetacean in Argentine waters. During the 1980s and 1990s, high levels of incidental mortality in purse and trawl fisheries were documented, and in recent decades tourism activities have been added as a potential source of disturbance.

The study objectives were to identify spatial genetic structure and regional genetic patterns of dusky dolphins along the Argentine coast. The variation of 413bp of the control region of 119 individuals over six locations spread along 2800 km (38°40'S to 54°30'S) was examined. Spatial genetic analyses, SAMOVA, genetic landscape shapes and autocorrelation analyses were conducted.

The most probable configuration was K=2, island population vs. continental populations (FCT= 0.774) and the spatial autocorrelation analysis showed a strong regional genetic structure, defining an operational unit at < 50 km.

The results provide valuable information that should be taken into account in the development of conservation strategies and management of the species; making the efforts focus on conserving vulnerable dusky dolphin groups by protecting their preferred coastal shallow habitat and by monitoring and regulating the dolphin watching and fishing activities, acting upon local populations along the Argentine coast.

Copyright © 2015 John Wiley & Sons, Ltd.
Females Have Larger Ratio of Second‐to‐Fourth Digits Than Males in Four Species of Salamandridae, Caudata
Authors: Kaczmarski Mikołaj , Kubicka Anna Maria , Tryjanowski Piotr , Hromada Martin
Published: February 2015

Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. It is considered to be a suitable biomarker of the in utero balance of fetal sex hormones, which affect early development of individuaĺs behavioral and morphological characteristics. In recent decades, digit ratio attracted a great attention in biology and psychology. However, for unmasking the biological basis of the phenomenon, extensive studies on non‐human animals are necessary. Despite it was hypothesized that digit ratio is well conserved in all Tetrapoda, and there exist studies on mammals, birds, and reptiles, there are only two such study on anuran amphibians. Therefore, the aim of this study is to investigate the 2D:4D in the most basal salamanders, Caudata. We have studied digit ratio in four species of newts: Triturus cristatus, Mesotriton alpestris, Lissotriton montandoni, and Lissotriton vulgaris, using museum collection. We used computerized measuring of each limbś photos. We have found out that, in M. alpestris, females 2D:4D of all four limbs were significantly larger than in males. In L. montandoni and L. vulgaris, only 2D:4D of rear limbs significantly differed, in females being larger. In T. cristatus, digit ratios of males and females did not statistically differ. Thus, the results confirmed our hypothesis that at least in M. alpestris, L. montandoni, and L. vulgaris, females seem to have larger 2D:4D comparing to males, the pattern known from most mammals and opposite to birds, reptiles and anuran amphibians. Anat Rec, 298:1424–1430, 2015. © 2015 Wiley Periodicals, Inc.
Pre‐Lapita decorated wood from Apalo, West New Britain, Papua New Guinea
Authors: Specht Jim , Lentfer Carol , Gosden Chris , Jacobsen Geraldine , Lindsay Sue
Published: February 2015

In 1989–1990, part of a wooden artefact with an incised criss‐cross design was recovered from the pre‐Lapita pottery level of the U‐L‐T area of the Apalo site in the Arawe Islands of New Britain, Papua New Guinea. The artefact was made from a Ficus tree species, and has been dated by AMS to 4043–3848 calBP (95.4%). This makes it the oldest directly dated ornamented object in the New Guinea region, though zoomorphic stone figurines and pestles and decorated stone mortars of the region are probably of similar antiquity. The artefact adds to the growing body of information about people in the Papua New Guinea Islands prior to the appearance of Lapita pottery, though the simplicity of the design and its widespread distribution in time and space caution against seeing it as a precursor to the Lapita design system. The nature of the original artefact is uncertain.
Designing New Analogs for Streamlining the Structure of Cytotoxic Lamellarin Natural Products
Authors: Tangdenpaisal Kassrin , Worayuthakarn Rattana , Karnkla Supatra , Ploypradith Poonsakdi , Intachote Pakamas , Sengsai Suchada , Saimanee Busakorn , Ruchirawat Somsak , Chittchang Montakarn
Published: February 2015

Despite the therapeutic potential of marine‐derived lamellarin natural products, their preclinical development has been hampered by their lipophilic nature, causing very poor aqueous solubility. In order to develop more drug‐like analogs, their structure was streamlined in this study from both the cytotoxic activity and lipophilicity standpoints. First, a modified total synthetic route was successfully devised to construct a library of 59 systematically designed lamellarin analogs, which were then subjected to cytotoxicity and log P determinations. Along with the 25 first‐generation lamellarins previously synthesized in our laboratory, the structure–activity and structure–lipophilicity relationships were extensively evaluated. Our results clearly indicated the additional structural requirements around the lamellarin skeleton which, when combined with those reported previously, can provide invaluable guidance for further modifications to increase the aqueous solubility of these compounds.
An alternative laboratory designed to address ethical concerns associated with traditional TAS2R38 student genotyping
Authors: LaBonte Michelle L. , Beers Melissa A.
Published: February 2015

The TAS2R38 alleles that code for the PAV/AVI T2R38 proteins have long been viewed as benign taste receptor variants. However, recent studies have demonstrated an expanding and medically relevant role for TAS2R38. The AVI variant of T2R38 is associated with an increased risk of both colorectal cancer and Pseudomonas aeruginosa‐associated sinus infection and T2R38 variants have been implicated in off‐target drug responses. To address ethical concerns associated with continued student TAS2R38 gene testing, we developed an alternative to the traditional laboratory genotyping exercise. Instead of determining their own genotype, introductory level students isolated plasmid DNA containing a section of the human TAS2R38 gene from Escherichia coli. Following PCR‐mediated amplification of a section of the TAS2R38 gene spanning the SNP at position 785, students determined their assigned genotype by restriction enzyme digestion and agarose gel electrophoresis. Using the course wide genotype and phenotype data, students found that there was an association between TAS2R38 genotype and the age of persistent P. aeruginosa acquisition in cystic fibrosis “patients.” Assessment data demonstrated that students taking part in this new TAS2R38 laboratory activity made clear learning gains. © 2015 by The International Union of Biochemistry and Molecular Biology, 43(2):100–109, 2015.
Evaluation and Applications of the Clinically Significant Change Method with the Violence Risk Scale‐Sexual Offender Version: Implications for Risk‐Change Communication
Authors: Olver Mark E. , Beggs Christofferson Sarah M. , Wong Stephen C. P.
Published: February 2015

We examined the use of the clinically significant change (CSC) method with the Violence Risk Scale‐Sexual Offender version (VRS‐SO), and its implications for risk communication, in a combined sample of 945 treated sexual offenders from three international settings, followed up for a minimum 5 years post‐release. The reliable change (RC) index was used to identify thresholds of clinically meaningful change and to create four CSC groups (already okay, recovered, improved, unchanged) based on VRS‐SO dynamic scores and amount of change made. Outcome analyses demonstrated important CSC‐group differences in 5‐year rates of sexual and violent recidivism. However, when baseline risk was controlled via Cox regression survival analysis, the pattern and magnitude of CSC‐group differences in sexual and violent recidivism changed to suggest that observed variation in recidivism base rates could be at least partly explained by pre‐existing group differences in risk level. Implications for communication of risk‐change information and applications to clinical practice are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Grant T. Harris (1950–2014)
Authors: Rice Marnie E.
Published: February 2015

This obituary of Dr. Grant Harris describes his life and the outstanding contributions he made to the field of correctional and forensic psychology.
Hypoxia‐induced proliferation in mesenchymal stem cells and angiotensin II‐mediated PI3K/AKT pathway
Authors: Zhang Yujuan , Lv Juanxiu , Guo Hui , Wei Xiaoguang , Li Weisheng , Xu Zhice
Published: February 2015

Hypoxia could stimulate proliferation of mesenchymal stem cells (MSCs) under certain conditions. This study determined angiotensin II mechanisms and PI3K/AKT pathway in hypoxia‐induced proliferation of MSCs. Hypoxia (3% oxygen) induced cellular proliferation in mouse MSCs and upregulated endogenous angiotensin II and angiotensin‐converting enzyme in the cell culture and expression of AT1 receptors. The expressions of Sox2, not Oct4 and Rex1, were significantly increased by the hypoxia. The blockade of AT1 receptors, not AT2 receptors, depressed hypoxia induced the proliferative effects. Both hypoxia and exogenous angiotensin II activated p‐AKT. Moreover, AT1 receptor inhibitor blocked the effects of hypoxia‐mediated p‐AKT upregulation. The data demonstrated that the hypoxia at 3% oxygen level could induce mouse MSC proliferation, probably as a result of the activation of PI3K signalling pathways via AT1 receptors. Copyright © 2015 John Wiley & Sons, Ltd.
Knockdown of CkrL by shRNA deteriorates hypoxia/reoxygenation‐induced H9C2 cardiomyocyte apoptosis and survival inhibition Via Bax and downregulation of P‐Erk1/2
Authors: Zhang Zhi‐Sheng , Yang Dong‐Yan , Fu Yan‐Bo , Zhang Lei , Zhao Qian‐Ping , Li Gang
Published: February 2015

Integrin β1 subunit and its downstream molecule integrin‐linked kinase and focal adhesion kinase have been confirmed to be essential to cell survival and inhibition of apoptosis and hypoxia/reoxygenation (H/R)‐induced injuries in cardiomyocytes. However, it is still unclear whether CrkL [v‐crk avian sarcoma virus CT‐10 oncogene homolog (Crk)‐like], which acts also as a component of the integrin pathway, could also affect H/R‐induced injuries in the cardiomyocytes. The rat‐derived H9C2 cardiomyocytes were infected with a CrkL small hairpin RNA interference recombinant lentivirus, which knockdowns the endogenous CrkL expression in the cardiomyocytes. Apoptosis, cell proliferation and survival were examined in the H9C2 cardiomyocytes treated with either H/R or not. Results showed that knockdown of CrkL could significantly increase apoptosis and inhibition of the cell proliferation and survival and deteriorate the previously mentioned injuries induced by H/R. In contrast, overexpression of human CrkL could relieve the exacerbation of the previously mentioned injuries induced by CrkL knockdown in the H9C2 cardiomyocytes via regulation of Bax and extracellular signal‐regulated kinase1/2 (p‐ERK1/2). In conclusion, these results confirmed that knockdown of CrkL could deteriorate H/R‐induced apoptosis and cell survival inhibition in rat‐derived H9C2 cardiomyocytes via Bax and downregulation of p‐ERK1/2. It implies that CrkL could mitigate H/R‐induced injuries in the cardiomyocytes. Copyright © 2015 John Wiley & Sons, Ltd.
The proteins (12 and 15 kDa) isolated from heat‐killed Lactobacillus plantarum L67 induces apoptosis in HT‐29 cells
Authors: Song S. , Oh S. , Lim K. T.
Published: February 2015

A number of scientific studies have revealed that Lactobacillus strains have beneficial bioactivities in the gastrointestinal tract. In this study, the production of intracellular reactive oxygen species (ROS) and the amounts of intracellular calcium, protein kinase C activity, cytochrome c, Bid, Bcl‐2, Bax and the apoptosis‐mediated proteins [caspase‐8, caspase‐3 and poly ADP ribose polymerase (PARP)] were evaluated to understand the induction of programmed cell death in HT‐29 cells by Lactobacillus plantarum L67. The results obtained from this study indicated that the relative intensities of the apoptotic‐related factors (intracellular ROS and intracellular calcium) and of apoptotic signals (Bax and t‐Bid) increased with increasing concentrations of the membrane proteins isolated from heat‐killed L. plantarum L67, whereas the relative intensities of cytochrome c, Bcl‐2, caspase‐8, caspase‐3 and PARP decreased. This study determines whether proteins (12 and 15 kDa) isolated from heat‐killed L. plantarum L67 induce programmed cell death in HT‐29 cells. Proteins isolated from L. plantarum L67 can stimulate the apoptotic signals and then consequently induce programmed cell death in HT‐29 cells. The results in this study suggest that the proteins isolated from L. plantarum L67 could be used as an antitumoural agent in probiotics and as a component of supplements or health foods. Copyright © 2015 John Wiley & Sons, Ltd.
Novel Approaches in Selective Tryptophan Isotope Labeling by Using Escherichia coli Overexpression Media
Authors: Schörghuber Julia , Sára Tomáš , Bisaccia Marilena , Schmid Walther , Konrat Robert , Lichtenecker Roman J.
Published: February 2015

NMR‐based investigations of large protein complexes require optimized isotopic labeling schemes. We report new methods to introduce stable isotopes into tryptophan residues; these are fine‐tuned to the requirements of the particular protein NMR experiment. Selective backbone labeling was performed by using a new α‐ketoacid precursor as an additive in cell‐based overexpression media. Additionally, we developed synthetic routes to certain isotopologues of indole with 13C–1H spin systems surrounded by 12C and 2H. The corresponding proteins, overexpressed in the presence of these precursor compounds, can be effectively analyzed for conformational changes in tryptophan residues in response to external stimuli, such as interaction with other proteins or small molecules.
Unusual Bonding and Properties in Main Group Element Chemistry: Rational Synthesis, Characterization, and Experimental Electron Density Determination of Mixed‐Valent Tetraphosphetes
Authors: Breuers Verena , Lehmann Christian W. , Frank Walter
Published: February 2015

Five dispirocyclic λ3,λ5‐tetraphosphetes [{R2Si(NR1)(NR2)P2}2] (R1= R2and R1≠ R2) are easily prepared in almost quantitative yields via photolysis of the respective bis(trimethylsilyl)phosphanyldiazaphosphasiletidines with intense visible light. These deep‐yellow low‐coordinate phosphorus compounds can be considered as the first higher congeners of the well‐known cyclodiphosphazenes. The tetraphosphetes are remarkably stable in air and show unexpected molecular properties related to the unique bonding situation of the central four‐π‐electron four‐membered phosphorus ring. The extent of rhombic distortion of the central P4ring is remarkable due to an unusually acute angle at the σ2‐phosphorus atoms. All of the PP bonds are approximately equal in length. The distances are in the middle of the range given by phosphorus single and double bonds. The anisotropic absorption of visible light that can easily be observed in the case of the yellow/colorless dichroic crystals of [{Me2Si(NtBu)(NtBu)P2}2] and the exceptional31P NMR chemical shift of the σ2‐phosphorus atoms are the most remarkable features of the λ3,λ5‐tetraphosphetes. In the case of [{Me2Si(NtBu)(NtBu)P2}2], the Hansen–Coppens multipole model is applied to extract the electron density from high‐resolution X‐ray diffraction data obtained at 100 K. Static deformation density and topological analysis reveal a unique bonding situation in the central unsaturated P4fragment characterized by polar σ‐bonding, pronounced out‐of‐ring non‐bonding lone pair density on the σ2‐phosphorus atoms, and an additional non‐classical three‐center back‐bonding contribution.
Gold‐Catalyzed Tandem Hydroamination/Formal Aza‐Diels–Alder Reaction of Homopropargyl Amino Esters: A Combined Computational and Experimental Mechanistic Study
Authors: Miró Javier , Sánchez‐Roselló María , González Javier , del Pozo Carlos , Fustero Santos
Published: February 2015

A tandem gold‐catalyzed hydroamination/formal aza‐Diels–Alder reaction is described. This process, which employs quaternary homopropargyl amino ester substrates, leads to the formation of an intrincate tetracyclic framework and involves the generation of four bonds and five stereocenters in a highly diastereoselective manner. Theoretical calculations have allowed us to propose a suitable mechanistic rationalization for the tandem protocol. Additionally, by studying the influence of the ligands on the rate of the gold‐catalyzed reactions, it was possible to establish optimum conditions in which to perform the process with a variety of substituents on the amino ester substrates. Notably, the asymmetric version of the tandem reaction was also evaluated.
Gold–Acetonyl Complexes: From Side‐Products to Valuable Synthons
Authors: Gasperini Danila , Collado Alba , Goméz‐Suárez Adrián , Cordes David B. , Slawin Alexandra M. Z. , Nolan Steven P.
Published: February 2015

A new synthetic strategy was devised leading to the formation of complexes, such as [Au(IPr)(CH2COCH3)]. The approach capitalizes on the formation of a decomposition product observed in the course of the synthesis of [Au(IPr)(Cl)]. A library of gold acetonyl complexes containing the most common N‐heterocyclic carbene (NHC) ligands has been synthesized. These acetonyl complexes are good synthons for the preparation of numerous organogold complexes. Moreover, they have proven to be precatalysts in common gold(I)‐catalyzed reactions.
Mechanism of Phosphine Borane Deprotection with Amines: The Effects of Phosphine, Solvent and Amine on Rate and Efficiency
Authors: Lloyd‐Jones Guy C. , Taylor Nicholas P.
Published: February 2015

The kinetics of borane transfer from simple tertiary phosphine borane adducts to a wide range of amines have been determined. All data obtained, including second‐order kinetics, lack of cross‐over, and negative entropies of activation for reaction of triphenylphosphine borane with quinuclidine and triethylamine, are consistent with a direct (SN2‐like) transfer process, rather than a dissociative (SN1‐like) process. The identities of the amine, phosphine, and solvent all impact substantially on the rate (k) and equilibrium (K) of the transfer, which in some cases vary by many orders of magnitude. P‐to‐N transfer is more efficient with cyclic amines in apolar solvents due to reduced entropic costs and ground‐state destabilisation. Taken as a whole, the data allow informed optimisation of the deprotection step from the stand‐point of rate, or synthetic convenience. In all cases, both reactants should be present at high initial concentration to gain kinetic benefit from the bimolecularity of the process. Ultimately, the choice of amine is dictated by the identity of the phosphine borane complex. Aryl‐rich phosphine boranes are sufficiently reactive to allow use of diethylamine or pyrrolidine as a volatile low polarity solvent and reactant, whereas more alkyl‐rich phosphines benefit from the use of more reactive amines, such as 1,4‐diaza[2.2.2]bicyclooctane (DABCO), in apolar solvents at higher temperatures.
Synthesis of Mesoporous Wall‐Structured TiO2 on Reduced Graphene Oxide Nanosheets with High Rate Performance for Lithium‐Ion Batteries
Authors: Zhen Mengmeng , Sun Meiqing , Gao Guandao , Liu Lu , Zhou Zhen
Published: February 2015

Mesoporous wall‐structured TiO2 on reduced graphene oxide (RGO) nanosheets were successfully fabricated through a simple hydrothermal process without any surfactants and annealed at 400 °C for 2 h under argon. The obtained mesoporous structured TiO2–RGO composites had a high surface area (99 0307 m2 g−1) and exhibited excellent electrochemical cycling (a reversible capacity of 260 mAh g−1 at 1.2 C and 180 mAh g−1 at 5 C after 400 cycles), demonstrating it to be a promising method for the development of high‐performance Li‐ion batteries.
Restriction of Molecular Twisting on a Gold Nanoparticle Surface
Authors: Debnath Tushar , Dana Jayanta , Maity Partha , Lobo Hyacintha , Shankarling Ganapati S. , Ghosh Hirendra N.
Published: February 2015

To understand the photophysical properties of intramolecular charge transfer (ICT) and twisted intramolecular charge transfer (TICT) states on a gold nanoparticle (Au NP) surface, we have designed and synthesized a new coumarin molecule (C3) that exists both as ICT and TICT states in its excited state in a polar environment. On a Au NP surface, an excited C3 molecule only exists as an ICT state owing to restricted molecular rotation of a diethylamino group; as a result, no conversion from the ICT to TICT state was observed. Selection of the preferential state of a molecule with dual emitting states can be helpful for selected biological applications.
Cycloelimination of Imidazolidin‐2‐ylidene N‐Heterocyclic Carbenes: Mechanism and Insights into the Synthesis of Stable “NHC‐CDI” Amidinates
Authors: Zhukhovitskiy Aleksandr V. , Geng Julie , Johnson Jeremiah A.
Published: February 2015

We report the discovery that 1,3‐bis(aryl)imidazolidin‐2‐ylidenes, one of the most widely studied classes of N‐heterocyclic carbenes (NHCs), undergo quantitative conversion to zwitterionic “NHC‐CDI” amidinates upon heating to ≈100 °C in solution. The mechanism of this novel NHC decomposition process is studied in detail. These studies enabled the rational synthesis of a new class of bench stable amidinates from a panel of NHCs and carbodiimides. We expect these constructs to find utility in a variety of applications.
Homocatenation of Aluminum: Alkane‐like Structures of Li2Al2H6 and Li3Al3H8
Authors: Gish J. Tyler , Popov Ivan A. , Boldyrev Alexander I.
Published: February 2015

A new class of aluminum homocatenated compounds (LinAlnH2n+2) is proposed based on quantum chemical calculations. In these compounds, Al abstracts an electron from Li, becoming valence isoelectronic with C, Si, and Ge, thus mimicking respective structural features of Group 14 hydrides. Using the Coalescence Kick search program coupled with density functional theory calculations, we investigated the potential energy surfaces of Li2Al2H6 and Li3Al3H6. Then single‐point‐energy coupled‐cluster calculations were performed for the lowest energy structures found. Indeed, the global minima established for Li2Al2H6 and Li3Al3H6 contain the Al2H62− and Al3H63− kernels, which are isostructural with ethane (C2H6), disilane (Si2H6), digermane (Ge2H6) and propane (C3H8), trisilane (Si3H8), trigermane (Ge3H8) molecules, respectively. Structural, energetic, and electronic characteristics of the Li2Al2H6 and Li3Al3H8 compounds are presented and the viability of their synthesis is discussed.
Single Oxygen‐Atom Insertion into PB Bonds: On‐ and Off‐Metal Transformation of a Borylphosphine into a Borylphosphinite
Authors: Bailey Jonathan A. , Sparkes Hazel A. , Pringle Paul G.
Published: February 2015

An oxygen atom is selectively inserted into the PB bond of a borylphosphine (L1) by reaction with Me3NO to afford the corresponding borylphosphinite (L2). This transformation can also be effected when L1 is coordinated to rhodium. The ν(CO) values for trans‐[RhCl(CO)(L)2] reveal very different electronic properties for coordinated L1 and L2 which translate into the strikingly different performances of the complexes [RhCl(L)(cod)] (L= L1 or L2, cod=1,5‐cyclooctadiene) in hydrosilylation and hydroboration catalysis.
Improved transformation‐based quantile regression
Authors: Geraci Marco , Jones M. C.
Published: February 2015

Modelling the quantiles of a random variable is facilitated by their equivariance to monotone transformations. In conditional modelling, transforming the response variable serves to approximate nonlinear relationships by means of flexible and parsimonious models; these usually include standard transformations as special cases. Transforming back to obtain predictions on the original scale or to calculate marginal nonlinear effects becomes a trivial task. This approach is particularly useful when the support of the response variable is bounded. We propose novel transformation models for singly or doubly bounded responses, which improve upon the performance of conditional quantile estimators as compared to other competing transformations, namely the Box–Cox and the Aranda‐Ordaz transformations. The key is to provide flexible transformations with range the whole of the real line. Estimation is carried out by means of a two‐stage estimator, while confidence intervals are obtained by bootstrap. A simulation study and some illustrative data analyses are presented.The Canadian Journal of Statistics43: 118–132; 2015 © 2015 Statistical Society of Canada
A simple model‐based approach to variable selection in classification and clustering
Authors: Partovi Nia Vahid , Davison Anthony C.
Published: February 2015

Clustering and classification of replicated data is often performed using classical techniques that inappropriately treat the data as unreplicated, or by complex modern ones that are computationally demanding. In this paper, we introduce a simple approach based on a “spike‐and‐slab” mixture model that is fast, automatic, allows classification, clustering and variable selection in a single framework, and can handle replicated or unreplicated data. Simulation shows that our approach compares well with other recently proposed methods. The ideas are illustrated by application to microarray and metabolomic data. The Canadian Journal of Statistics 43: 157–175; 2015 © 2015 Statistical Society of Canada
Synthesis of Hollow BiVO4/Ag Composite Microspheres and Their Photocatalytic and Surface‐Enhanced Raman Scattering Properties
Authors: Chen Limiao , Yu Yifan , Wu Min , Huang Jianhan , Liu Younian , Liu Xiaohe , Qiu Guanzhou
Published: February 2015

Hollow BiVO4 microspheres are prepared in the presence of ethylenediaminetetraacetic acid (EDTA) through a hydrothermal method, and used as a template for the fabrication of Ag‐nanoparticle‐decorated BiVO4 (BiVO4/Ag) composite microspheres. The morphology and structure are characterized by transmission electron microscopy and scanning electron microscopy. It is found that EDTA plays an important role in the formation of the hollow microspheres, and the possible formation mechanism is discussed. UV/visible spectrometry analysis shows that the BiVO4/Ag composite microspheres exhibit a distinct surface plasmon absorption band compared with pure BiVO4 microspheres. The photocatalytic activities of the BiVO4/Ag composite microspheres are examined by studying the degradation of rhodamine 6G (R6G) solutions under visible‐light irradiation (>400 nm). The results show clearly that the BiVO4/Ag composite microspheres possess a much higher photocatalytic activity than pure BiVO4 microspheres and P25. In addition, Raman analyses show that the BiVO4/Ag composite microspheres exhibit an excellent surface‐enhanced Raman scattering (SERS) performance.
Controlled Oriented Attachment of Bipyramidal‐Shaped Anatase TiO2 and Their Enhanced Performance in Dye‐Sensitized Solar Cells
Authors: Yang Shuang , Zheng Yi Chu , Hou Yu , Yang Hua Gui
Published: February 2015

A low‐cost hydrothermal method was used to synthesize high‐purity bipyramidal single‐crystals of TiO2 enclosed with high percentage of (101) facets. The oriented attachment behavior can be controlled by fine tuning the reaction temperature. This played an important role in determining the crystal growth along [001] direction resulting in the self‐assembly of the bipyramid crystals into connected ones to form single‐crystal nanrods without the loss of surface area. In addition, the relationship between oriented attachment and the photovoltaic performance of such anatase TiO2 nanocrystals in photoanodes of DSCs was investigated. The highly oriented sample reached a maximum overall energy conversion efficiency of 8.63 %. These results further illustrated that the highly oriented samples have superior charge transport ability derived from the enhanced long‐range atomic arrangement with reduced grain boundaries and comparable uptake of dye molecules.
Fourier analysis of scratches generated on m‐GaN substrates during polishing
Authors: Serafińczuk Jarosław , Jóźwiak Grzegorz , Pałetko Piotr , Kudrawiec Robert , Kucharski Robert , Zajac Marcin , Gotszalk Teodor Paweł
Published: February 2015

Generation of scratches on surface of m‐plane GaN substrates due to polishing was studied by atomic force microscopy (AFM). For epi‐ready substrates AFM images confirm a flat surface with the atomic step roughness while a lot of scratches are visible in AFM images for partially polished GaN substrates. The Fourier analysis of AFM images show that scratches propagate easier along {c‐plane} and {a‐plane} directions on m‐plane GaN surface. This observation is an evidence of anisotropy of mechanical properties of GaN crystals in the micro‐scale. This anisotropy is directly correlated with the symmetry and atomic arrangement of m‐plane GaN.
Carbon‐Supported Base Metal Nanoparticles: Cellulose at Work
Authors: Hoekstra Jacco , Versluijs‐Helder Marjan , Vlietstra Edward J. , Geus John W. , Jenneskens Leonardus W.
Published: February 2015

Pyrolysis of base metal salt loaded microcrystalline cellulose spheres gives a facile access to carbon‐supported base metal nanoparticles, which have been characterized with temperature‐dependent XRD, SEM, TEM, ICP‐MS and elemental analysis. The role of cellulose is multifaceted: 1) it facilitates a homogeneous impregnation of the aqueous base metal salt solutions, 2) it acts as an efficacious (carbonaceous) support material for the uniformly dispersed base metal salts, their oxides and the metal nanoparticles derived therefrom, and 3) it contributes as a reducing agent via carbothermal reduction for the conversion of the metal oxide nanoparticles into the metal nanoparticles. Finally, the base metal nanoparticles capable of forming metastable metal carbides catalytically convert the carbonaceous support into a mesoporous graphitic carbon material.
Consider structure, advantages of competency‐based programs
Authors: Hope Joan
Published: February 2015

WASHINGTON, D.C. — If your institution doesn't already offer competency‐based programs, they might be coming soon. In September 2012, there were about 20 of these programs offered, said Alison Kadlec, senior vice president and director of higher education and workforce programs for Public Agenda. Currently, at least 200 programs are available.
Take a proactive approach to protect your institution from data breaches
Authors: Rice David , Firuz Paul
Published: February 2015

Colleges and universities possess an immense amount of sensitive, personally identifiable information. This information may include employees' and students' Social Security numbers, educational records, health information, financial information, and data associated with payment accounts. Strict legal requirements govern how this data must be collected, managed and used.
Tree height–diameter allometry across the United States
Authors: Hulshof Catherine M. , Swenson Nathan G. , Weiser Michael D.
Published: February 2015

The relationship between tree height and diameter is fundamental in determining community and ecosystem structure as well as estimates of biomass and carbon storage. Yet our understanding of how tree allometry relates to climate and whole organismal function is limited. We used the Forest Inventory and Analysis National Program database to determine height–diameter allometries of 2,976,937 individuals of 293 tree species across the United States. The shape of the allometric relationship was determined by comparing linear and nonlinear functional forms. Mixed‐effects models were used to test for allometric differences due to climate and floristic (between angiosperms and gymnosperms) and functional groups (leaf habit and shade tolerance). Tree allometry significantly differed across the United States largely because of climate. Temperature, and to some extent precipitation, in part explained tree allometric variation. The magnitude of allometric variation due to climate, however, had a phylogenetic signal. Specifically, angiosperm allometry was more sensitive to differences in temperature compared to gymnosperms. Most notably, angiosperm height was more negatively influenced by increasing temperature variability, whereas gymnosperm height was negatively influenced by decreasing precipitation and increasing altitude. There was little evidence to suggest that shade tolerance influenced tree allometry except for very shade‐intolerant trees which were taller for any given diameter. Tree allometry is plastic rather than fixed and scaling parameters vary around predicted central tendencies. This allometric variation provides insight into life‐history strategies, phylogenetic history, and environmental limitations at biogeographical scales.
Analysis of Nitric Oxide from Chemical Donors Using CMOS Platinum Microelectrodes
Authors: Feeny Rachel M. , Wydallis John B. , Chen Tom , Tobet Stuart , Reynolds Melissa M. , Henry Charles S.
Published: February 2015

Electrochemical detection of NO generated from chemical donors is reported. Because NO is an important biological messenger, many donor sources and detection methods have been developed. Few reports have characterized NO donors using electrochemistry despite electrochemical techniques being sensitive and selective. Here, a CMOS platinum microelectrode array is interfaced with a microfluidic device for the electrochemical analysis of NO from (Z)‐1‐[N‐(2‐aminoethyl)‐N‐(2‐ammonioethyl)amino]diazen‐1‐ium‐1,2‐diolate (DETA/NO). The donor parent amine fouls the electrode, resulting in substantial signal loss, but an electrochemical cleaning method was developed that substantially reduces fouling and allows detection of NO between 90 nM and 1 µM.
Screen Printed Alizarin‐Based Carbon Electrodes: Monitoring pH in Unbuffered Media
Authors: Dai Chencheng , Song Peng , Wadhawan Jay D. , Fisher Adrian C. , Lawrence Nathan S.
Published: February 2015

An alizarin based voltammetric pH sensor is introduced. This device is fabricated by screen printing the alizarin, which is a pH‐sensitive redox compound, mixed with carbon ink onto the carbon aluminum (aluminum foil coated with carbon paste). This electrode shows a Nernst response to both the buffered and unbuffered media, with a potential shift by 55.8 mV/pH unit and a working range up to pH 10. This approach suggests a disposable, reproducible, low‐cost method for pH sensing with the possibility of miniaturization. A further study of this type of sensor coated with nafion reveals a possible method to expand the working range and improve the stability.
Be ready to manage enrollment for competency‐based programs
Authors: Hope Joan
Published: February 2015

WASHINGTON, D.C. — If your institution doesn't already offer competency‐based programs, they might be coming soon. In September 2012, there were about 20 of these programs offered, said Alison Kadlec, senior vice president and director of higher education and workforce programs for Public Agenda. Currently, at least 200 of the programs are available.
Answer student questions with an online automated response system
Authors: Hope Joan
Published: February 2015

When Michelle H. Brown‐Nevers became associate vice president of student registration and financial services at the University of Pennsylvania in 2008, she reviewed the statistics on telephone and email service her staff members provided. “The telephone statistics were a bit alarming,” she said. The demand was exceeding capacity.
Take steps to ensure customer satisfaction
Authors: Hope Joan
Published: February 2015

Adrian R. Cornelius wants people to leave his office feeling that they have been well‐served. Whether they are students, colleagues, faculty members or anyone else, his goal is for them to be satisfied with the service the Registrar's Office at the University of Maryland College Park provides.
Hydraulic properties of concentrated flow of a bank gully in the dry‐hot valley region of southwest China
Authors: Su Zhengan , Xiong Donghong , Dong Yifan , Zhang Baojun , Zhang Su , Zheng Xueyong , Yang Dan , Zhang Jianhui , Fan Jianrong , Fang Haidong
Published: February 2015

To quantify spatiotemporal variation in hydraulic properties of bank gully concentrated flow, a series of scour experiments were run under water discharge rates ranging from 30 to 120 l min−1. Concentrated flows were found to be turbulent and supercritical in the upstream catchment area and downstream gully beds. As discharge increased, values of the soil erosion rate, Reynolds number (Re), shear stress, stream power, and flow energy consumption (ΔE) increased while values of the Froude number (Fr) and the Darcy–Weisbach friction factor (resistance f ) did not. With the exception of gully headcut collapse under discharge rates of 60, 90, and 120 l min−1, a declining power function trend (P < 0.05) in the soil erosion rate developed in the upstream catchment area, headcuts, and downstream gully beds. However, increasing trends were observed in temporal variations of hydraulic properties for downstream gully beds and the upstream catchment area. Despite significant differences in temporal variation between the soil erosion rate and hydraulic property values, relative steady state conditions of the soil erosion rate and ΔE were attained following an initial period of adjustment in the upstream catchment area, headcuts, and downstream gully beds under different discharge rates. A logarithmic growth of flow energy consumption per unit soil loss (ΔEu) was observed in bank gullies and the upstream catchment area as the experiment progressed, further illustrating the actual reason behind the discrepancy in temporal variation between soil erosion rates and ΔE. Results demonstrate that ΔE can be used to estimate headcut erosion soil loss, but further quantitative studies are required to quantify coupling effects between hydraulic properties and vertical variation in soil mechanical properties on temporal variation for bank gully soil erosion rates. Copyright © 2015 John Wiley & Sons, Ltd.