bluuebunny/crossref_metadata_2025 huggingface dataset:
Self‐Assembled Hybrid Molybdenum Phosphonate Porous Nanomaterials and Their Catalytic Activity for the Synthesis of Benzimidazoles
Authors: Pramanik Malay , Bhaumik Asim
Published: August 2014

A new porous organic–inorganic hybrid molybdenum phosphonate nanomaterial (HMoP‐1) was synthesized through the reaction of benzene‐1,3,5‐triphosphonic acid and molybdenum(V) chloride under hydrothermal conditions in the absence of any structure‐directing agent. The morphology of the hybrid material was found to be different at different synthesis temperatures. The material synthesized at 423 K (HMoP‐1‐LT) has spherical particle morphology, and the material synthesized at 453 K (HMoP‐1‐HT) has self‐assembled flakelike morphology. Powder XRD, field‐emission SEM, high‐resolution TEM, N2 sorption, solid‐state 13C cross‐polarization magic‐angle spinning NMR and 31P magic‐angle spinning NMR analyses, X‐ray photoelectron spectroscopy, thermogravimetric differential thermal analysis, NH3 temperature‐programmed adsorption, and FTIR spectroscopic techniques were employed to characterize the samples and understand the morphological diversity. The orthorhombic crystal phase of the material was established through REFLEX and CELSIZ unit cell refinement programs. The calculated unit cell parameters of HMoP‐1‐HT are a=8.001(0.046) Å b=7.029 (0.039) Å, c=6.010 (0.036) Å; whereas HMoP‐1‐LT is amorphous in nature. HMoP‐1‐HT shows outstanding catalytic activity and high recycling efficiency for the green and efficient one‐pot condensation reaction for the synthesis of bioactive 2‐aryl benzimidazoles in excellent yields at room temperature.
Two‐Photon‐Induced Fluorescence in New π‐Expanded Diketopyrrolopyrroles
Authors: Grzybowski Marek , Hugues Vincent , Blanchard‐Desce Mireille , Gryko Daniel T.
Published: August 2014

Structurally unique π‐expanded diketopyrrolopyrroles (EDPP) were designed and synthesized. Strategic placement of a fluorene scaffold at the periphery of a diketopyrrolopyrrole through tandem Friedel–Crafts‐dehydration reactions resulted in dyes with supreme solubility. The structure of the dyes was confirmed by X‐ray crystallography verifying a nearly flattened arrangement of the ten fused rings. Despite the extended ring system, the dye still preserved good solubility and was further functionalized by using Pd‐catalyzed coupling reactions, such as the Buchwald–Hartwig amination. Photophysical studies of these new functional dyes revealed that they possess enhanced properties when compared with expanded DPPs in terms of two‐photon absorption cross‐section. It is further demonstrated that in addition to the initial diacetals, the final electrophilic cyclization step can also be applied to diketones. By placing two amine groups at peripheral positions of the resulting dyes, values of two‐photon absorption cross‐section on the level of 2000 GM around 1000 nm were achieved, which in combination with high fluorescence quantum yield (Φfl), generated a two‐photon brightness of approximately 1600 GM. These characteristics in combination with strong red emission (665 nm) make these new π‐expanded diketopyrrolopyrroles of major promise as two‐photon dyes for bioimaging applications. Finally, the corresponding N‐alkylated DPPs displayed a solid‐state fluorescence.
Computational Study of van der Waals Complexes between Borylenes and Hydrocarbons
Authors: Krasowska Małgorzata , Bettinger Holger F.
Published: August 2014

The addition of borylenes (RB) to prototypical carboncarbon multiple bonds (ethyne, ethene) and the insertion into a CH bond of methane involves weakly bound van der Waals complexes of the reaction partners according to computational chemistry methods. Geometries of all complexes were optimized using spin‐component scaled second‐order Møller–Plesset perturbation theory (SCS‐MP2) in combination with a quadruple‐ζ (def2‐QZVP) basis set. Energies were further refined using the coupled‐cluster (CCSD(T)) method in combination with basis sets up to quadruple‐ζ quality (def2‐QZVP and aug‐cc‐pVTZ). All of the complexes of borylenes studied correspond to shallow minima on their potential‐energy surfaces. Borylene complexes with ethyne are the most stable and those with methane are the least stable ones. Aminoborylene complexes BNHR with ethyne and ethene are stabilized mainly by NH⋅⋅⋅π interactions. Symmetry‐adapted perturbation theory (SAPT) was performed to analyze the nature of the interaction between borylene molecules and hydrocarbons. Most of the ethyne complexes are dominated by electrostatic interactions, whereas for most of the ethene and all of the methane complexes the interaction is mainly dispersive.
Trisphosphine‐Chelate‐Substituted Molybdenum and Tungsten Nitrosyl Hydrides as Highly Active Catalysts for Olefin Hydrogenations
Authors: Chakraborty Subrata , Blacque Olivier , Fox Thomas , Berke Heinz
Published: August 2014

Reaction of [M(NO)Cl3(NCMe)2] (M=Mo, W) with (iPr2PCH2CH2)2PPh (etpip) at room temperature afforded the syn/anti‐[M(NO)Cl3(mer‐etpip)] complexes (M=Mo, a; W, b; 3 a,b(syn,anti); syn and anti refer to the relative position of Ph(etpip) and NO). Reduction of 3 a,b(syn,anti) produced [M(NO)Cl2(mer‐etpip)] (4 a,b(syn)), [M(NO)Cl(NCMe)(mer‐etpip)] (5 a,b(syn,anti)), and [M(NO)Cl(η2‐ethylene)(mer‐etpip)] (6 a,b(syn,anti)) complexes. The hydrides [M(NO)H(η2‐ethylene)(mer‐etpip)] (7 a,b(syn,anti)) were obtained from 6 a,b(syn,anti) using NaHBEt3 (75 °C, THF) or LiBH4 (80 °C, Et3N), respectively. 7 a,b(syn,anti) were probed in olefin hydrogenations in the absence or presence of a hydrosilane/B(C6F5)3 mixture. The 7 a,b(syn,anti)/Et3SiH/B(C6F5)3 co‐catalytic systems were highly active in various olefin hydrogenations (60 bar H2, 140 °C), with maximum TOFs of 5250 h−1 (7 a(syn,anti)) and 8200 h−1 (7 b(syn,anti)) for 1‐hexene hydrogenation. The Et3SiH/(B(C6F5)3 co‐catalyst is anticipated to generate a [Et3Si]+ cation attaching to the ONO atom. This facilitates NO bending and accelerates catalysis by providing a vacant site. Inverse DKIE effects were observed for the 7 a(syn,anti)/Et3SiH/(B(C6F5)3 (kH/kD=0.55) and the 7 b(syn,anti)/Et3SiH/(B(C6F5)3 (kH/kD=0.65) co‐catalytic mixtures (20 bar H2/D2, 140 °C).
Unexpected Drastic Decrease in the Excited‐State Electronic Communication between Porphyrin Chromophores Covalently Linked by a Palladium(II) Bridge
Authors: Abdelhameed Mohammed , Karsenti Paul‐Ludovic , Langlois Adam , Lefebvre Jean‐François , Richeter Sébastien , Ruppert Romain , Harvey Pierre D.
Published: August 2014

A dyad built up of a zinc(II) porphyrin and the corresponding free base, [Zn‐Fb], fused to N‐heterocyclic carbene (NHCs) ligands, respectively acting as singlet energy donor and acceptor, and a bridging trans‐PdI2 unit, along with the corresponding [Zn‐Zn] and [Fb‐Fb] dimers were prepared and investigated by absorption and emission spectroscopy and density functional computations. Despite favorable structural and spectroscopic parameters, unexpectedly slow singlet energy transfer rates are measured in comparison with the predicted values by the Förster theory and those observed for other structurally related dyads. This observation is rationalized by the lack of large molecular orbital (MO) overlaps between the frontier MOs of the donor and acceptor, thus preventing a double electron exchange through the trans‐PdI2 bridge, and by an electronic shielding induced by the presence of this same linker preventing the two chromophores to fully interact via their transition dipoles.
Acid/Base Switching of the Tautomerism and Conformation of a Dioxoporphyrin for Integrated Binary Subtraction
Authors: Ding Yubin , Li Xin , Hill Jonathan P. , Ariga Katsuhiko , Ågren Hans , Andréasson Joakim , Zhu Weihong , Tian He , Xie Yongshu
Published: August 2014

Compared with most of the reported logic devices based on the supramolecular approach, systems based on individual molecules can avoid challenging construction requirements. Herein, a novel dioxoporphyrin DPH22 was synthesized and two of its tautomers were characterized by single‐crystal X‐ray diffraction studies. Compound DPH22 exhibits multichannel controllable stepwise tautomerization, protonation, and deprotonation processes through interactions with H+ and F− ions. By using the addition of H+ and F− ions as inputs and UV/Vis absorption values at λ=412, 510, 562, and 603 nm as outputs, the controlled tautomerism of DPH22 has been successfully used for the construction of an integrated molecular level half‐subtractor and comparator. In addition, this acid/base‐switched tautomerism is reversible, thus endowing the system with ease of reset and recycling; consequently, there is no need to modulate complicated intermolecular interactions and electron‐/charge‐transfer processes.
Synthesis of Pyridazinones through the Copper(I)‐Catalyzed Multicomponent Reaction of Aldehydes, Hydrazines, and Alkynylesters
Authors: Mantovani Anderson C. , Goulart Tales A. C. , Back Davi F. , Zeni Gilson
Published: August 2014

The copper‐catalyzed multicomponent cyclization reaction, which combined aldehydes, hydrazines, and alkynylesters, was applied in the synthesis of pyridazinones. The reaction was regioselective and gave only six‐membered pyridazinones in the complete absence of five‐membered pyrazoles or a regioisomeric mixture. During this investigation, the use of 2‐halobenzaldehyde as the starting material, under identical reaction conditions, gave 6‐(2‐ethoxyphenyl)pyridazinones after sequential Michael addition/1,2‐addition/Ullmann cross‐coupling reactions.
Microwave‐assisted oxygen storage level estimation for three‐way catalyst control: Model‐based development and benchmarking of selected control strategies
Authors: Schödel Sebastian , Votsmeier Martin , Fischerauer Gerhard
Published: August 2014

It has recently been shown that the oxygen content of a three‐way catalyst can be observed directly by a microwave‐assisted technique. In this contribution, several control strategies based on this microwave measurement approach are proposed. In the first step, the lambda probe downstream of the catalyst is replaced by the microwave‐based state observer. In the second step, the microwave‐based state observer replaces both lambda probes, upstream and downstream of the catalyst. A model‐based rapid control prototyping approach is used to test the selected control schemes and to compare their performance to the conventional air‐fuel ratio control. This comparison is completed using a complex catalyst model and measured data for a realistic driving cycle. It is shown that under idealized conditions the new microwave‐based control strategies can outperform the conventional lambda control based on two lambda probes. One important result is that improving the time resolution of the current microwave measurement system is essential to use the full potential of the new approach.
Ribonuclease A Inhibition by Carboxymethylsulfonyl‐Modified Xylo‐ and Arabinopyrimidines
Authors: Datta Dhrubajyoti , Dasgupta Swagata , Pathak Tanmaya
Published: August 2014

A group of acidic nucleosides were synthesized to develop a new class of ribonuclease A (RNase A) inhibitors. Our recent study on carboxymethylsulfonyl‐modified nucleosides revealed some interesting results in RNase A inhibition. This positive outcome triggered an investigation of the role played by secondary sugar hydroxy groups in inhibiting RNase A activity. Uridines and cytidines modified with SO2CH2COOH groups at the 2′‐ and 3′‐positions show good inhibitory properties with low inhibition constant (Ki) values in the range of 109–17 μM. The present work resulted in a set of inhibitors that undergo more effective interactions with the RNase A active site, as visualized by docking studies.
Towards zero latency photonic switching in shared memory networks
Authors: Madarbux Muhammad Ridwan , Van Laer Anouk , Watts Philip M. , Jones Timothy M.
Published: August 2014

Optical networks on chip based on silicon photonics have been proposed to reduce latency and power consumption in future chip multiprocessors. However, high performance chip multiprocessors use a shared memory model, which generates large numbers of short messages, creating high arbitration latency overhead for photonic switching networks. In this paper, we explore techniques that intelligently use information from the memory hierarchy to predict communication in order to setup photonic circuits with reduced or eliminated arbitration latency. Firstly, we present a switch scheduling algorithm, which arbitrates on a per memory transaction basis and holds open photonic circuits to exploit temporal locality. We show that this can reduce the average arbitration latency overhead by 60% and eliminate arbitration latency altogether for up to 70% of memory transactions. We then demonstrate that this switch scheduling algorithm operating with a central photonic crossbar or Clos switch has significant energy efficiency benefits over arbitration‐free photonic networks such as single writer multiple reader networks. Finally, we demonstrate that cache miss prediction can be used to predict 86% of more complex memory transactions involving multiple nodes or main memory. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis of Cyclophellitol, Cyclophellitol Aziridine, and Their Tagged Derivatives
Authors: Li Kah‐Yee , Jiang Jianbing , Witte Martin D. , Kallemeijn Wouter W. , van den Elst Hans , Wong Chung‐Sing , Chander Sharina D. , Hoogendoorn Sascha , Beenakker Thomas J. M. , Codée Jeroen D. C. , Aerts Johannes M. F. G. , van der Marel Gijs A. , Overkleeft Herman S.
Published: August 2014

Cyclitol epoxides and aziridines are potent and selective irreversible inhibitors of retaining glycosidases. We have previously reported on our studies on the use of activity‐based probes derived from cyclophellitol and from its aziridine analogue for activity‐based profiling of retaining β‐glucosidases in vitro, in situ, and in some examples also in vivo. In this work we disclose full details of the synthesis, purification, and analysis of a comprehensive panel of cyclophellitol analogues, all featuring the β‐glucose configuration and designed as tools for selective inhibition and/or imaging of human acid glucosylceramidase (epoxides) or as broad‐spectrum probes for retaining β‐glucosidases (aziridines).
Synthesis of α‐ and β‐Galactopyranose‐Configured Isomers of Cyclophellitol and Cyclophellitol Aziridine
Authors: Willems Lianne I. , Beenakker Thomas J. M. , Murray Benjamin , Gagestein Berend , van den Elst Hans , van Rijssel Erwin R. , Codée Jeroen D. C. , Kallemeijn Wouter W. , Aerts Johannes M. F. G. , van der Marel Gijsbert A. , Overkleeft Herman S.
Published: August 2014

Cyclophellitol and cyclophellitol aziridine are potent and irreversible mechanism‐based inhibitors of retaining β‐glucosidases. Alterations in the configuration of these compounds can lead to irreversible inhibition of different classes of retaining glycosidases. We have recently reported on the design of a set of α‐galactopyranose‐configured cyclophellitol and cyclophellitol aziridine derivatives that inhibit human retaining α‐galactosidases. Moreover, we have shown that fluorescently labeled derivatives enable the activity‐based profiling of these enzymes in vitro. In this report we describe in detail the synthetic strategies that were used to obtain these epoxide‐ and aziridine‐based probes. In addition, we describe the parallel synthesis of a set of β‐galactopyranose‐configured cyclophellitol isomers as putative inhibitors of retaining β‐galactosidases.
Oncometabolites‐driven tumorigenesis: From genetics to targeted therapy
Authors: Morin Aurélie , Letouzé Eric , Gimenez‐Roqueplo Anne‐Paule , Favier Judith
Published: August 2014

Although the alteration of cellular metabolism in cancer was reported by Warburg in the early 1930s, a regain of interest in cancer metabolism has more recently followed the discovery of germline or somatic mutations in genes coding for metabolic enzymes (succinate dehydrogenase, fumarate hydratase and isocitrate dehydrogenase) that are associated with tumor susceptibility. Mutations in these genes are found in numerous tumor types including paragangliomas, kidney cancers, leiomyomas, glioblastomas and acute myeloid leukemia. They lead to the accumulation of so‐called oncometabolites that behave as competitors of 2‐oxoglutarate‐dependent dioxygenases, involved in a broad spectrum of pathways such as hypoxic response and epigenetic reprogramming. Here, we review the diverse pathways affected by oncometabolites, their potential role in cancer formation, maintenance, metastasis and sensitivity to chemotherapies, as well as emerging new therapeutic strategies.
Construction of Efficient Solid Emitters with Tetraphenylethene Trimers for Non‐doped Blue OLEDs
Authors: Huang Jing , Sun Ning , Wang Jinyu , Tang Runli , Li Xuefeng , Dong Jingfeng , Li Qianqian , Ma Dongge , Li Zhen
Published: August 2014

Three TPE trimers with meta or para linkage modes have been successfully synthesized. When fabricated as emissive layers in non‐doped OLEDs, they all exhibit blue or deep‐blue emissions with maximum current efficiency up to 4.03 cd A−1, further verifying the facile but ingenious approach by utilizing meta‐linkage mode in longer conjugated systems.
Precession electron diffraction‐assisted crystal phase mapping of metastable c‐GaN films grown on (001) GaAs
Authors: Ruiz‐Zepeda Francisco , Casallas‐Moreno Yenny L. , Cantu‐Valle Jesus , Alducin Diego , Santiago Ulises , José‐Yacaman Miguel , López‐López Máximo , Ponce Arturo
Published: August 2014

The control growth of the cubic meta‐stable nitride phase is a challenge because of the crystalline nature of the nitrides to grow in the hexagonal phase, and accurately identifying the phases and crystal orientations in local areas of the nitride semiconductor films is important for device applications. In this study, we obtained phase and orientation maps of a metastable cubic GaN thin film using precession electron diffraction (PED) under scanning mode with a point‐to‐point 1 nm probe size beam. The phase maps revealed a cubic GaN thin film with hexagonal GaN inclusions of columnar shape. The orientation maps showed that the inclusions have nucleation sites at the cubic GaN {111} facets. Different growth orientations of the inclusions were observed due to the possibility of the hexagonal {0001} plane to grow on any different {111} cubic facet. However, the generation of the hexagonal GaN inclusions is not always due to a 60° rotation of a {111} plane. These findings show the advantage of using PED along with phase and orientation mapping, and the analysis can be extended to differently composed semiconductor thin films. Microsc. Res. Tech. 77:980–985, 2014. © 2014 Wiley Periodicals, Inc.
Orthorhombic YAlO3 – a novel many‐phonon SRS‐active crystal
Authors: Kaminskii Alexander A. , Lux Oliver , Hanuza Jerzy , Rhee Hanjo , Eichler Hans Joachim , Yoneda Hitoki , Zhang Jian , Tang Dingyuan , Shirakawa Akira
Published: August 2014

In single crystals of orthorhombic YAlO3, widely known as a host‐matrix for Ln3+‐lasant ions, many‐phonon stimulated Raman scattering interactions as well as different manifestations of cascaded and cross‐cascaded nonlinear χ(3)↔χ(3) processes are initiated by picosecond laser pulses. The scientific and applicative potential of YAlO3 crystals is considerably expanded by the demonstration of its SRS properties. In particular, the studies revealed the manifestation of eight χ(3)‐active vibrational modes. The corresponding Stokes and anti‐Stokes lines have been assigned and the steady‐state Raman gain coefficients related to the strongest phonon mode have been estimated. In addition, a short review presents the stimulated emission channels of its Ln3+‐ions together with some χ(3)‐nonlinear laser properties of crystals belonging to the binary Y2O3‐Al2O3 system.
Generation‐Dependent Gel–Fluid Phase Transition of Membrane Caused by a PAMAM Dendrimer
Authors: Xie Li‐Qiang , Feng Jia‐Wei , Tian Wen‐de , Ma Yu‐Qiang
Published: August 2014

Coarse‐grained molecular dynamics simulations are performed to investigate the effects of dendrimer size and lipid phase on the dendrimer–membrane interactions. It is found that the low‐generation dendrimer flattens on the gel‐phase bilayer without any disturbance of lipids, while dendrimers with immediate generation can fluidize the upper leaflet of the membrane. High‐generation dendrimers can induce the gel–fluid phase transition of lipids in the vicinity of the dendrimer and the significant bending of membranes. The phase transition is companied by membrane thinning and facilitates a domain formation on the membrane. The findings suggest that high‐generation dendrimers are much more effective in disturbing membranes not only at high temperature but also at low temperature. This work is helpful to understand the binding and internalization mechanisms of cationic nanoparticles into cells involving lipid rafts and endocytosis.
An Implicit Solvent Ionic Strength (ISIS) Method to Model Polyelectrolyte Systems with Dissipative Particle Dynamics
Authors: Li Nan K. , Fuss William H. , Yingling Yaroslava G.
Published: August 2014

Herein, a new coarse‐grained methodology for modeling and simulations of polyelectrolyte systems using implicit solvent ionic strength (ISIS) with dissipative particle dynamics (DPD) is presented. This ISIS model is based on mean‐field theory approximation and the soft repulsive potential is used to reproduce the effect of solvent ionic strength. The capability of the ISIS model is assessed via two test cases: dynamics of a single long polyelectrolyte chain and the self‐assembly of polyelectrolyte diblock copolymers in aqueous solutions with variable ionic strength. The results are in good agreement with previous experimental observations and theoretical predictions, which indicates that our polyelectrolyte model can be used to effectively and efficiently capture salt‐dependent conformational features of large‐scale polyelectrolyte systems in aqueous solutions, especially at the salt‐dominated regime.
MRS water resonance frequency in childhood brain tumours: a novel potential biomarker of temperature and tumour environment
Authors: Babourina‐Brooks Ben , Wilson Martin , Arvanitis Theodoros N. , Peet Andrew C. , Davies Nigel P.
Published: August 2014

1H MRS thermometry has been investigated for brain trauma and hypothermia monitoring applications but has not been explored in brain tumours. The proton resonance frequency (PRF) of water is dependent on temperature but is also influenced by microenvironment factors, such as fast proton exchange with macromolecules, ionic concentration and magnetic susceptibility. 1H MRS has been utilized for brain tumour diagnostic and prognostic purposes in children; however, the water PRF measure may provide complementary information to further improve characterization. Water PRF values were investigated from a repository of MRS data acquired from childhood brain tumours and children with apparently normal brains. The cohort consisted of histologically proven glioma (22), medulloblastoma (19) and control groups (28, MRS in both the basal ganglia and parietal white matter regions). All data were acquired at 1.5 T using a short TE (30 ms) single voxel spectroscopy (PRESS) protocol. Water PRF values were calculated using methyl creatine and total choline. Spectral peak amplitude weighted averaging was used to improve the accuracy of the measurements. Mean PRF values were significantly larger for medulloblastoma compared with glioma, with a difference in the means of 0.0147 ppm (p < 0.05), while the mean PRF for glioma was significantly lower than for the healthy cohort, with a difference in the means of 0.0061 ppm (p < 0.05). This would suggest the apparent temperature of the glioma group was ~1.5 °C higher than the medulloblastomas and ~0.7 °C higher than a healthy brain. However, the PRF shift may not reflect a change in temperature, given that alterations in protein content, microstructure and ionic concentration contribute to PRF shifts. Measurement of these effects could also be used as a supplementary biomarker, and further investigation is required. This study has shown that the water PRF value has the potential to be used for characterizing childhood brain tumours, which has not been reported previously. © 2014 The Authors. NMR in Biomedicine published by John Wiley & Sons, Ltd.
Photoelectron emission from lithiated diamond
Authors: O'Donnell Kane M. , Martin Tomas L. , Edmonds Mark T. , Tadich Anton , Thomsen Lars , Ristein Jürgen , Pakes Christopher I. , Fox Neil A. , Ley Lothar
Published: August 2014

This paper reviews electron emission from negative electron affinity (NEA) diamond and gives account of the recent developments in alternatives to hydrogen‐termination for producing NEA diamond surfaces, particularly using lithium on oxygen‐terminated diamond. We discuss the background and motivation for using alkali metals and present both experimental and computational results that cover structure, electronic properties, photoemission, and total photoyield. Secondary yield enhancement of over 200 × is demonstrated over a reference surface with positive electron affinity.
Optical and EPR characterization of Er3+ centers in SrTiO3 single crystals
Authors: Skvortsov Alexander , Savchenko Dariya , Potucek Zdenek , Jastrabik Lubomir , Trepakov Vladimir , Dejneka Alexandr
Published: August 2014

We report on optical absorption and EPR spectroscopy studies of low Er doped (50 ppm) SrTiO3 single crystals. In the region of 400–650 nm a set of optical intra‐configurational f–f transitions from the 4I15/2 ground state to the excited 4F9/2, 4S3/2, 2H11/2, and 2H9/2 Stark sublevels of the Er3+ impurity ions were observed and identified. At T = 2 K the number of registered optical transitions evidences the presence of only one type of Er3+ centers with non‐cubic symmetry. The system of the energy levels for Er3+ excited states is determined. The X‐band EPR spectra at 5.2 K revealed the rhombic symmetry of Er3+ impurity centers. The components of a rhombic g‐tensor were defined. It was suggested that Er ions substitute Sr ions in A‐sublattice sites.
Covariant equations for geophysical fluids with an asymmetric gravitational potential and their hydrostatic limit
Authors: Charron Martin , Zadra Ayrton
Published: August 2014

Starting from the governing equations in tensor form for non‐hydrostatic fluid dynamics, the hydrostatic limit is obtained by introducing a scaling parameter. This allows the use of the same fundamental tensor equations to describe the dynamics of non‐hydrostatic and hydrostatic geophysical fluids, possibly combined with geometric approximations, while preserving the dynamical consistency of the governing equations in arbitrary coordinates. This provides the tools to reproduce in a systematic manner the quartet of equations—deep/non‐hydrostatic, deep/hydrostatic, shallow/non‐hydrostatic, and shallow/hydrostatic—presented elsewhere. This quartet is generalised to the case where the gravitational potential has no spatial symmetries.
Fair treatment comparisons in observational research
Authors: Lopiano Kenneth K. , Obenchain Robert L. , Young S. Stanley
Published: August 2014

The proliferation of electronic health records, driven by advances in technology and legislative measures, is stimulating interest in the analysis of passively collected administrative and clinical data. Observational data present exciting challenges and opportunities to researchers interested in comparing the effectiveness of different treatment regimes and, as personalized medicine requires, estimating how effectiveness varies among subgroups. In this study, we provide new motivation for the local control approach to the analysis of large observational datasets in which patients are first clustered in pretreatment covariate space and treatment comparisons are made within subgroups of similar patients. The motivation for such an analysis is that the resulting local treatment effect estimates make inherently fair comparisons even when treatment cohorts suffer variation in balance (treatment choice fraction) across pretreatment covariate space. We use an example of Simpson's paradox to show that estimates of the overall average treatment effect, which marginalize over covariate space, can be misleading. Thus, we provide an alternative definition that uses a single, shared marginal distribution to define overall treatment comparisons that are inherently fair given the observed covariates. However, we also argue that overall treatment comparisons should no longer be the focus of comparative effectiveness research; the possibility that treatment effectiveness does vary across patient subpopulations must not be left unexplored. In the spirit of the now ubiquitous concept of personalized medicine, estimating heterogeneous treatment effects in clinically relevant subgroups will allow for, within the limits of the available data, fair treatment comparisons that are more relevant to individual patients.
The Effect of Doppler Ultrasound on Early Vascular Interventions and Clinical Outcomes After Liver Transplantation
Authors: Lee Hannah , Lim Chae‐Won , Yoo Seok Ha , Koo Chang‐Hoon , Kwon Woo‐Il , Suh Kyung‐Suk , Ryu Ho Geol
Published: August 2014

Background

During the immediate postoperative period after liver transplantation (LT), postoperative bleeding and vascular complications (stenosis, thrombosis) are the two most common complications that require therapeutic decisions. Doppler ultrasound (DUS) is the established method for screening vascular patency after LT during the immediate postoperative period. The objective of our study was to evaluate the impact of DUS performed on postoperative days (POD) 1 and 2 on early vascular interventions.

Methods

We studied 200 patients who had undergone living donor or deceased donor liver transplantation between January 2011 and March 2012. Postoperative liver DUS findings of up to POD 14, including patency of hepatic artery, portal vein, and hepatic vein, were retrieved. Patients with normal DUS findings on POD 1 and POD 2 were classified as the normal early DUS group. Patients with abnormal DUS findings at POD1 or POD2 were classified as the abnormal early DUS group. Frequency of vascular interventions was compared between the two groups. Risk factors that predict vascular interventions also were assessed.

Results

On POD 1 and 2, 81.5 % (163/200) had normal DUS findings and management was not altered by subsequent DUS findings. Two patients in the normal group were found to have hepatic artery dissection and hepatic vein thrombosis on routine CT on POD 7 and received vascular intervention. DUS results in the two patients were normal until POD 6, but DUS performed after the CT on POD 7 were consistent with the CT findings. Of the 37 recipients who showed abnormal DUS findings on POD 1 or 2, the DUS findings were normalized or unchanged thereafter in 33 patients and no vascular interventions were performed. Two patients underwent hepatic artery thrombectomy on POD 2, one patient required a portal vein thrombectomy on POD 1, and one patient died on POD 3 due to bleeding. The overall incidence of vascular complication requiring vascular interventions was 2.5 %. Logistic regression identified abnormal DUS findings on POD 1 or 2 as an independent risk factor of vascular complications requiring intervention.

Conclusions

In LT recipients who demonstrate normal DUS findings in the first 2 postoperative days, additional DUS screening may have value only when clinically indicated.
A Pilot Study of BRCA Mutation Carriers’ Knowledge About the Clinical Impact of Prophylactic‐oophorectomy and Views on Fertility Consultation: A Single‐Center Pilot Study
Authors: Kim J. , Skrzynia C. , Mersereau J. E.
Published: August 2014

BRCA mutation carriers will experience early surgically induced menopause following prophylactic bilateral salpingo‐oophorectomy (PBSO). This pilot study aimed to investigate their (1) knowledge about the clinical impact of PBSO; (2) views on fertility consultation (FC)/fertility preservation (FP) treatment; and (3) difficulties in conceiving compared to non‐carriers. A cross‐sectional, single institution web‐survey was performed at a university‐based IVF center. Women aged 18–50 years who were screened for BRCA gene mutations from 2005 to 2013 were recruited via mail. Forty‐one BRCA‐positive and 110 BRCA‐negative women completed the survey (response rate: 50 %). The knowledge about the reproductive impact of PBSO was limited, with the majority of women in this highly educated sample only identifying the correct response 64 % of the time. Among BRCA mutation carriers, 24 (59 %) had positive views about FC/FP treatments. A larger proportion of women with no children at the time of BRCA testing, and those who were non‐white tended to have positive views toward FP. Women with, versus without, BRCA mutations were more likely to have difficulty in conceiving (p = 0.08). This well‐educated group had limited knowledge about the reproductive clinical impact of PBSO, or the benefit of a FP before PBSO. Most women with BRCA mutations were interested in FC/FP treatment if they had not completed childbearing at the time of screening. Targeted referrals for FC at the time of BRCA screening may help women improve knowledge and allow improved decision‐making about reproductive options.
Amide‐Based Surfactants from Methyl Glucoside as Potential Emulsifiers
Authors: Salman Salih Mahdi , Heidelberg Thorsten , Hussen Rusnah Syahila Duali , Tajuddin Hairul Anuar Bin
Published: August 2014

A series of amide‐linked surfactants from methyl glucoside was synthesized and investigated for their potential use as water‐in‐oil emulsifiers. The synthetic concept combined a nucleophilic substitution approach with a Staudinger coupling of the intermediate azide. Both straight and Guerbet‐type branched fatty acids ranging from C8 to C16 were applied. All surfactants exhibited very high Krafft temperatures, which were related to the amide linkage and exclusively formed the hexagonal H1‐phase. The Guerbet C16 surfactant enabled the formation of a stable water‐in‐oil gel at ambient temperature, which, however, required heating to form the corresponding fluid emulsion.
Plasma Polymerization Modified Polyvinylidene Fluoride (PVDF) Membrane Development and Characterization for Degumming of Soybean Oil
Authors: Onal‐Ulusoy Baran , Tur Eren , Akdoğan Ebru , Mutlu Mehmet
Published: August 2014

Unmodified and surface‐modified polyvinylidene fluoride (PVDF) membranes were tested for their ability to degum soybean crude oil and crude oil miscellas. The membrane was modified with 1,1,1,3,3,3‐hexafluoro‐2‐propanol or hexamethyldisiloxane (HMDSO) by radio‐frequency plasma polymerization at 10–100 W glow discharge power and 1–30 min contact time. The membranes were characterized by contact angle measurements, attenuated total reflectance Fourier transform infrared spectroscopy, atomic force microscopy, and scanning electron microscopy. Modification of the PVDF membrane with HMDSO at 60 W power for 5 min increased the interfacial free energy between water and solid surface from 30 ± 2 to 64 ± 2 mJ/m2. This membrane was tested for permeate flux and phospholipid rejection with crude oil and different concentrations of miscella. Although formation of the polymer film on the membrane tended to decrease membrane pore size, the modified membrane had an oil flux as good as the unmodified membrane did. In addition, the modified‐membrane improved the phospholipid rejection and removed 76 % of the phospholipids from the crude oil and 81–90 % of the phospholipids from crude oil miscellas.
Influence of flue gas cleaning system on characteristics of PM2.5 emission from coal-fired power plants
Authors: Wang Ao , Song Qiang , Tu Gongming , Wang Hui , Yue Yong , Yao Qiang
Published: August 2014

This study investigated the influence of precipitators and wet flue gas desulfurization equipment on characteristics of PM2.5 emission from coal-fired power stations. We measured size distribution and removal efficiencies, including hybrid electrostatic precipitator/bag filters (ESP/BAGs) which have rarely been studied. A bimodal distribution of particle concentrations was observed at the inlet of each precipitator. After the precipitators, particle concentrations were significantly reduced. Although a bimodal distribution was still observed, all peak positions shifted to the smaller end. The removal efficiencies of hybrid ESP/BAGs reached 99 % for PM2.5, which is considerably higher than those for other types of precipitators. In particular, the influence of hybrid ESP/BAG operating conditions on the performance of dust removal was explored. The efficiency of hybrid ESP/BAGs decreased by 1.9 % when the first electrostatic field was shut down. The concentrations and distributions of particulate matter were also measured in three coal-fired power plants before and after desulfurization devices. The results showed diverse removal efficiencies for different desulfurization towers. The reason for the difference requires further research. We estimated the influence of removal technology for particulate matter on total emissions in China. Substituting ESPs with hybrid ESP/BAGs could reduce the total emissions to 104.3 thousand tons, with 47.48 thousand tons of PM2.5.
Early phase clinical trials to identify optimal dosing and safety
Authors: Cook Natalie , Hansen Aaron R. , Siu Lillian L. , Abdul Razak Albiruni R.
Published: August 2014

The purpose of early stage clinical trials is to determine the recommended dose and toxicity profile of an investigational agent or multi‐drug combination. Molecularly targeted agents (MTAs) and immunotherapies have distinct toxicities from chemotherapies that are often not dose dependent and can lead to chronic and sometimes unpredictable side effects. Therefore utilizing a dose escalation method that has toxicity based endpoints may not be as appropriate for determination of recommended dose, and alternative parameters such as pharmacokinetic or pharmacodynamic outcomes are potentially appealing options. Approaches to enhance safety and optimize dosing include improved preclinical models and assessment, innovative model based design and dose escalation strategies, patient selection, the use of expansion cohorts and extended toxicity assessments. Tailoring the design of phase I trials by adopting new strategies to address the different properties of MTAs is required to enhance the development of these agents. This review will focus on the limitations to safety and dose determination that have occurred in the development of MTAs and immunotherapies. In addition, strategies are proposed to overcome these challenges to develop phase I trials that can more accurately define the recommended dose and identify adverse events.
Modelling of material pitting from cavitation bubble collapse
Authors: Hsiao Chao-Tsung , Jayaprakash A. , Kapahi A. , Choi J.-K. , Chahine Georges L.
Published: August 2014

Material pitting from cavitation bubble collapse is investigated numerically including two-way fluid–structure interaction (FSI). A hybrid numerical approach which links an incompressible boundary element method (BEM) solver and a compressible finite difference flow solver is applied to capture non-spherical bubble dynamics efficiently and accurately. The flow codes solve the fluid dynamics while intimately coupling the solution with a finite element structure code to enable simulation of the full FSI. During bubble collapse high impulsive pressures result from the impact of the bubble re-entrant jet on the material surface and from the collapse of the remaining bubble ring. A pit forms on the material surface when the impulsive pressure is large enough to result in high equivalent stresses exceeding the material yield stress. The results depend on bubble dynamics parameters such as the size of the bubble at its maximum volume, the bubble standoff distance from the material wall, and the pressure driving the bubble collapse. The effects of these parameters on the re-entrant jet, the following bubble ring collapse pressure, and the generated material pit characteristics are investigated.
Buoyant convection from a discrete source in a leaky porous medium
Authors: Roes Mark A. , Bolster Diogo T. , Flynn M. R.
Published: August 2014

The application of turbulent plume theory in describing the dynamics of emptying filling boxes, control volumes connected to an infinite exterior through a series of openings along the upper and lower boundaries, has yielded novel strategies for the natural ventilation of buildings. Making the plume laminar and having it fall through a porous medium yields a problem of fundamental significance in its own right, insights from which may be applied, for example, in minimizing the contamination of drinking water by geologically sequestered $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}{\mathrm{CO}}_2$ or the chemicals leached from waste piles. After reviewing the theory appropriate to rectilinear and axisymmetric plumes in porous media, we demonstrate how the model equations may be adapted to the case of an emptying filling box. In this circumstance, the long-time solution consists of two ambient layers, each of which has a uniform density. The lower and upper layers comprise fluid that is respectively discharged by the plume and advected into the box through the upper opening. Our theory provides an estimate for both the height and thickness of the associated interface in terms of, for example, the source volume and buoyancy fluxes, the outlet area and permeability, and the depth-average solute dispersion coefficient, which is itself a function of the far-field horizontal flow speed. Complementary laboratory experiments are provided for the case of a line source plume and show very good agreement with model predictions. Our measurements also indicate that the permeability, $k_f$, of the lower opening (or fissure) decreases with the density of the fluid being discharged, a fact that has been overlooked in some previous studies, wherein $k_f$ is assumed to depend only on the fissure geometry.
Different patterns of Australian adults' knowledge of foods and nutrients related to metabolic disease risk
Authors: Worsley Anthony , Wang Wei C. , Byrne Stephanie , Yeatman Heather
Published: August 2014

A nationwide survey of 2022 consumers was conducted in Australia in late 2011. A short list of questions about knowledge of the nutrient composition of common foods was administered along with questions about the respondents' food attitudes, demographics, school education and dieting practices. Overall, the results showed that nutrition knowledge was relatively high. Latent class analysis showed two groups of consumers with ‘high’ and ‘low’ knowledge of nutrition. Higher knowledge was positively associated with age, female sex, university education, experience of home economics or health education at school, having a chronic disease, and attitudes to food issues, and negatively with type 1 diabetes or the use of diabetes-control diets. The implications of the findings for nutrition communication are discussed.
Mannoheptulose has differential effects on fasting and postprandial energy expenditure and respiratory quotient in adult Beagle dogs fed diets of different macronutrient contents
Authors: McKnight Leslie L. , Flickinger Elizabeth A. , France James , Davenport Gary M. , Shoveller Anna K.
Published: August 2014

The present study aimed to determine the effects of mannoheptulose (MH) (8 mg/kg) on energy expenditure (EE), respiratory quotient (RQ) and glycaemic response in healthy adult Beagle dogs (n8; 9·62 (sem0·31) kg; body condition score 4·5). The study was designed as replicated 4 × 4 Latin squares with a 2 × 2 factorial treatment structure. The dietary treatments were low carbohydrate (CHO) relative to fat diet (LC; 31 % CHO, 28 % fat) with placebo (0 mg/kg) or MH supplement and high CHO relative to fat diet (HC; 54 % CHO, 11 % fat) with placebo (0 mg/kg) or MH supplement. Dogs were fed to maintain body weight (HC and HC+MH3625 (sem295) kJ and LC and LC+MH3542 (sem284) kJ). Resting and postprandial (0–4 h; 5–10 h; 11–17 h; 18–23 h) EE and RQ were determined by indirect calorimetry (days 12 or 14). Glycaemic response to a meal (24 h) and plasma MH concentrations were determined on days 12 or 14. Plasma MH followed first-order kinetics, confirming that MH is absorbed and available to the animal. In the presence of high dietary CHO, MH increased postprandial EE (5–10 h only), suggesting MH increased dietary induced thermogenesis. In contrast to earlier reports, MH did not affect serum glucose or insulin in the present study. Irrespective of MH, dogs adapted RQ to diet composition and dogs consuming the LC diet had a greater incremental AUC for glucose, but not insulin, than dogs consuming the HC diet.
Millimetre-Wave Site Characteristics at the Australia Telescope Compact Array
Authors: Indermuehle Balthasar T. , Burton Michael G.
Published: August 2014

We present a millimetre-wave site characterisation for the Australia Telescope Compact Array (ATCA) based on nearly 9 yr of data from a seeing monitor operating at this facility. The seeing monitor, which measures the phase fluctuations in the signal from a geosynchronous satellite over a 230-m baseline caused by water vapour fluctuations along their sight lines, provides an almost gapless record since 2005, with high time resolution. We determine the root mean square (rms) of the path length variations as a function of time of day and season. Under the assumption of the ‘frozen screen’ hypothesis, we also determine the Kolmogorov exponent, α, for the turbulence and the phase screen speed. From these, we determine the millimetre-wave seeing at λ = 3.3 mm. Based on the magnitude of the rms path length variations, we estimate the expected fraction of the available observing time when interferometry could be successfully conducted using the ATCA, as a function of observing frequency and antenna baseline, for the time of day and the season. We also estimate the corresponding observing time fractions when using the water vapour radiometers installed on the ATCA in order to correct for the phase fluctuations occurring during the measurement of an astronomical source.
Multinationals and Economic Development in Italy during the Twentieth Century
Authors: Colli Andrea
Published: August 2014

As a host country for foreign direct investment, conventional measures suggest that Italy is not a very attractive location. However, based upon a new database of the one hundred largest multinationals in the country, this article shows that foreign firms consistently played a crucial role in Italy's industrial activities throughout the twentieth century. A detailed analysis of investment patterns, distribution across industries, and entry modes reveals that they concentrated their investment in sectors of high technological and scale intensity, such as chemicals and pharmaceuticals, where domestic capabilities and competition remained weak during much of the period.