bluuebunny/crossref_metadata_2025 huggingface dataset:
Criteria for first- and second-order vibrational resonances and correct evaluation of the Darling-Dennison resonance coefficients using the canonical Van Vleck perturbation theory
Authors: Krasnoshchekov Sergey V. , Isayeva Elena V. , Stepanov Nikolay F.
Published: December 2014

The second-order vibrational Hamiltonian of a semi-rigid polyatomic molecule when resonances are present can be reduced to a quasi-diagonal form using second-order vibrational perturbation theory. Obtaining exact vibrational energy levels requires subsequent numerical diagonalization of the Hamiltonian matrix including the first- and second-order resonance coupling coefficients. While the first-order Fermi resonance constants can be easily calculated, the evaluation of the second-order Darling-Dennison constants requires more complicated algebra for seven individual cases with different numbers of creation-annihilation vibrational quanta. The difficulty in precise evaluation of the Darling-Dennison coefficients is associated with the previously unrecognized interference with simultaneously present Fermi resonances that affect the form of the canonically transformed Hamiltonian. For the first time, we have presented the correct form of the general expression for the evaluation of the Darling-Dennison constants that accounts for the underlying effect of Fermi resonances. The physically meaningful criteria for selecting both Fermi and Darling-Dennison resonances are discussed and illustrated using numerical examples.
Time dependent hydraulic falls and trapped waves over submerged obstructions
Authors: Page C. , Părău E. I.
Published: December 2014

We consider the classical problem of a free surface flowing past one or more disturbances in a channel. The fluid is assumed to be inviscid and incompressible, and the flow, irrotational. Both the effects of gravity and surface tension are considered. The stability of critical flow steady solutions, which have subcritical flow upstream of the disturbance and supercritical flow downstream, is investigated. We compute the initial steady solution using boundary integral equation techniques based on Cauchy integral formula and advance the solution forward in time using a mixed Euler-Lagrange method along with Adams-Bashforth-Moulton scheme. Both gravity and gravity-capillary critical flow solutions are found to be stable. The stability of solutions with a train of waves trapped between two disturbances is also investigated in the pure gravity and gravity-capillary cases.
The effects of variable fluid properties on thin film stability
Authors: D’Alessio S. J. D. , Seth C. J. M. P. , Pascal J. P.
Published: December 2014

A theoretical investigation has been conducted to study the impact of variable fluid properties on the stability of gravity-driven flow of a thin film down a heated incline. The incline is maintained at a uniform temperature which exceeds the temperature of the ambient gas above the fluid and is thus responsible for heating the thin fluid layer. The variable fluid properties are allowed to vary linearly with temperature. It is assumed that long-wave perturbations are most unstable. Based on this, a stability analysis was carried out whereby the governing linearized perturbation equations were expanded in powers of the wavenumber which is a small parameter. New interesting results illustrating how the critical Reynolds number and perturbation phase speed depend on the various dimensionless parameters have been obtained.
Radiative transitions of excited ions moving slowly in plasmas
Authors: Hu Hongwei , Zhao Yongtao , Li Zhen , Li Fuli , Dong Chenzhong , Zhou Xianming , Chen Wencong , Li Peng
Published: December 2014

The electric dipole transitions of excited ions moving slowly in plasmas are studied. The results show that some transitions forbidden for excited ions at rest become allowed for moving excited ions. The transition rates change with varying speed of the ions. Forbidden transitions are strongly influenced by the speed, non-forbidden transitions are weakly influenced.
Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling
Authors: Wang Hong , Lee Sung-Min , Wang James L. , Lin Hua-Tay
Published: December 2014

Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 108 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications, such as piezoelectric fuel injectors in heavy-duty diesel engines.
The effect of molecular mobility on electronic transport in carbon nanotube-polymer composites and networks
Authors: Shenogin Sergei , Lee Jonghoon , Voevodin Andrey A. , Roy Ajit K.
Published: December 2014

A multiscale modeling approach to the prediction of electrical conductivity in carbon nanotube (CNT)–polymer composite materials is developed, which takes into account thermally activated molecular mobility of the matrix and the CNTs. On molecular level, a tight-binding density functional theory and non-equilibrium Green's function method are used to calculate the static electron transmission function in the contact between two metallic carbon nanotubes that corresponds to electron transport at 0 K. For higher temperatures, the statistical distribution of effective contact resistances is considered that originates from thermal fluctuations of intermolecular distances caused by molecular mobility of carbon nanotube and the polymer matrix. Based on this distribution and using effective medium theory, the temperature dependence of macroscopic electrical resistivity for CNT-polymer composites and CNT mats is calculated. The predicted data indicate that the electrical conductivity of the CNT-polymer composites increases linearly with temperature above 50 K, which is in a quantitative agreement with the experiments. Our model predicts a slight nonlinearity in temperature dependence of electric conductivity at low temperatures for percolated composites with small CNT loading. The model also explains the effect of glass transition and other molecular relaxation processes in the polymer matrix on the composite electrical conductivity. The developed multiscale approach integrates the atomistic charge transport mechanisms in percolated CNT-polymer composites with the macroscopic response and thus enables direct comparison of the prediction with the measurements of macroscopic material properties.
Effect of Joule heating on isoelectric focusing of proteins in a microchannel
Authors: Yoo Kisoo , Shim Jaesool , Dutta Prashanta
Published: December 2014

Electric field-driven separation and purification techniques, such as isoelectric focusing (IEF) and isotachophoresis, generate heat in the system that can affect the performance of the separation process. In this study, a new mathematical model is presented for IEF that considers the temperature rise due to Joule heating. We used the model to study focusing phenomena and separation performance in a microchannel. A finite volume-based numerical technique is developed to study temperature-dependent IEF. Numerical simulation for narrow range IEF (6 < pH < 10) is performed in a straight microchannel for 100 ampholytes and two model proteins: staphylococcal nuclease and pancreatic ribonuclease. Separation results of the two proteins are obtained with and without considering the temperature rise due to Joule heating in the system for a nominal electric field of 100 V/cm. For the no Joule heating case, constant properties are used, while for the Joule heating case, temperature-dependent titration curves and thermo-physical properties are used. Our numerical results show that the temperature change due to Joule heating has a significant impact on the final focusing points of proteins, which can lower the separation performance considerably. In the absence of advection and any active cooling mechanism, the temperature increase is the highest at the mid-section of a microchannel. We also found that the maximum temperature in the system is a strong function of the ΔpK  value of the carrier ampholytes. Simulation results are also obtained for different values of applied electric fields in order to find the optimum working range considering the simulation time and buffer temperature. Moreover, the model is extended to study IEF in a straight microchip where pH is formed by supplying H+ and OH−, and the thermal analysis shows that the heat generation is negligible in ion supplied IEF.
Room-temperature near-infrared silicon carbide nanocrystalline emitters based on optically aligned spin defects
Authors: Muzha A. , Fuchs F. , Tarakina N. V. , Simin D. , Trupke M. , Soltamov V. A. , Mokhov E. N. , Baranov P. G. , Dyakonov V. , Krueger A. , Astakhov G. V.
Published: December 2014

Bulk silicon carbide (SiC) is a very promising material system for bio-applications and quantum sensing. However, its optical activity lies beyond the near infrared spectral window for in-vivo imaging and fiber communications due to a large forbidden energy gap. Here, we report the fabrication of SiC nanocrystals and isolation of different nanocrystal fractions ranged from 600 nm down to 60 nm in size. The structural analysis reveals further fragmentation of the smallest nanocrystals into ca. 10-nm-size clusters of high crystalline quality, separated by amorphization areas. We use neutron irradiation to create silicon vacancies, demonstrating near infrared photoluminescence. Finally, we detect room-temperature spin resonances of these silicon vacancies hosted in SiC nanocrystals. This opens intriguing perspectives to use them not only as in-vivo luminescent markers but also as magnetic field and temperature sensors, allowing for monitoring various physical, chemical, and biological processes.
Role of recombination pathway competition in spatially resolved cathodoluminescence spectroscopy
Authors: Toth Milos , Zachreson Cameron , Aharonovich Igor
Published: December 2014

Cathodoluminescence (CL) analysis enables characterization of optoelectronic materials and devices with high spatial resolution. However, data interpretation is complicated by the competitive nature of the CL generation process. Specifically, spatially resolved CL profiles are affected by both CL center distributions, and by the unknown distributions of recombination centers that do not generate peaks in measured CL spectra. Here, we use depth-resolved CL to show that the contribution of the latter can be deduced and removed from spatially resolved CL data. The utility of this technique is demonstrated using CL depth profiles of color centers in diamond.
Tuning the optical emission of MoS2 nanosheets using proximal photoswitchable azobenzene molecules
Authors: Li Juan , Wierzbowski Jakob , Ceylan Özlem , Klein Julian , Nisic Filippo , Anh Tuan Le , Meggendorfer Felix , Palma Carlos-Andres , Dragonetti Claudia , Barth Johannes V. , Finley Jonathan J. , Margapoti Emanuela
Published: December 2014

We report photoluminescence measurements performed on monolayer- and two-layer-MoS2 placed on two types of mixed self-assembled monolayers (mSAMs) of photoswitchable azobenzene molecules. The two mSAMs differ via the electronegative character of the azobenzene derivatives. Thin layers of a transition metal dichalcogenide—MoS2—were mechanically exfoliated on mSAM to allow for direct interaction between the molecules and the MoS2 layers. When the MoS2 nanosheet is in contact with the electropositive azobenzene molecules in trans configuration, an emission side band at lower energies and at low excitation powers suggest n-type doping. The photoisomerization of the molecules from trans to cis configuration lowers the doping, quenching the side band and enhancing the overall PL efficiency by a factor of ∼3. Opposite results were observed with the chlorinated, more electronegative molecules, exhibiting a reversed trend in the PL efficiency between trans and cis, but with an overall larger intensity. The type of doping induced by the two types of mSAMs was determined by Kelvin probe force microscopy technique.
Large magnetoresistance from long-range interface coupling in armchair graphene nanoribbon junctions
Authors: Li Suchun , Son Young-Woo , Quek Su Ying
Published: December 2014

In recent years, bottom-up synthesis procedures have achieved significant advancements in atomically controlled growth of several-nanometer-long graphene nanoribbons with armchair-shaped edges (AGNRs). This greatly encourages us to explore the potential of such well-defined AGNRs in electronics and spintronics. Here, we propose an AGNR based spin valve architecture that induces a large magnetoresistance up to 900%. We find that, when an AGNR is connected perpendicularly to zigzag-shaped edges, the AGNR allows for long-range extension of the otherwise localized edge state. The huge magnetoresistance is a direct consequence of the coupling of two such extended states from both ends of the AGNR, which forms a perfect transmission channel. By tuning the coupling between these two spin-polarized states with a magnetic field, the channel can be destroyed, leading to an abrupt drop in electron transmission.
On the nature of the linewidth enhancement factor in p-doped quantum dash based lasers
Authors: Joshi Siddharth , Chimot Nicolas , Ramdane Abderrahim , Lelarge François
Published: December 2014

P-doped quantum dash based lasers have shown superior dynamic performance as compared to their un-doped counterparts. This improvement in performance is strongly observed in line-width enhancement factor. These devices show a dramatic reduction in the αH parameter, resulting in very low chirp. This letter discusses the nature line-width enhancement factor of p-doped quantum dash lasers as opposed to un-doped counterparts. Owing to the p-doping a low and bias-stable alpha parameter is demonstrated.
High thermal stability and low density variation of carbon-doped Ge2Sb2Te5 for phase-change memory application
Authors: Zhou Wangyang , Wu Liangcai , Zhou Xilin , Rao Feng , Song Zhitang , Yao Dongning , Yin Weijun , Song Sannian , Liu Bo , Qian Bo , Feng Songlin
Published: December 2014

Carbon-doped Ge2Sb2Te5 (GSTC) film has been experimentally studied as a thermal stable material for high temperature applications. The 10-yr data retention temperature is remarkably increased through C doping. Furthermore, GSTC films have better interface properties after annealing at 410 °C for 30 min. The density variation of GSTC film is significantly improved, which is very important to device reliability. X-ray photoelectron spectroscopy results reveal that the thermal stability enhancement of GSTC film attributes to the forming of C-Ge, C-Sb, and C-Te bonds. The perfect thermal stability makes GSTC materials a good candidate in the actual production of phase-change memory.
Controlling the quantity of α-Fe inside multiwall carbon nanotubes filled with Fe-based crystals: The key role of vapor flow-rate
Authors: Boi Filippo S. , Maugeri Serena , Guo Jian , Lan Mu , Wang Shanling , Wen Jiqiu , Mountjoy Gavin , Baxendale Mark , Nevill George , Wilson Rory M. , He Yi , Zhang Sijie , Xiang Gang
Published: December 2014

The growth control of α-Fe inside multiwall carbon nanotubes has challenged researchers for more than a decade owing to the coexistence of this phase with Fe3C and γ-Fe. Previously, long heating treatments of 20 h have been used to decompose the encapsulated Fe-phases in C and Fe; however, these methods were limited by an unusual oxidation process leading to nanotube decomposition. In this letter, we report an alternative chemical vapour deposition approach that through an accurate control of the ferrocene-vapour flow-rate allows to achieve the direct encapsulation of 95% of α-Fe without additional heating treatments.
Plasmonic enhancement in hybrid organic/Si heterojunction solar cells enabled by embedded gold nanoparticles
Authors: Xia Zhouhui , Song Tao , Sun Jun , Lee Shuit-Tong , Sun Baoquan
Published: December 2014

We investigate the incorporation of gold nanoparticles (Au NPs) into poly(3,4-ethylenedioxythiophene)/polystyrenesulfonate for organic/Si heterojunction hybrid solar cells. The incorporation of Au NPs can enhance the short-circuit current density (Jsc), consequently, leading to a higher power conversion efficiency (PCE). The hybrid devices incorporating Au NPs with optimized size achieve a PCE of over 12.9% with about 10% enhancement of the Jsc compared with that of reference ones. Au NPs with different sizes are incorporated to explore the mechanism for the enhanced device performance. According to the detailed experimental characterization and numerical simulation results, the increased PCE is attributed to the light scattering and the local electromagnetic field enhancement, which is originated from the excitation of the localized surface plasmon resonance of Au NPs.
Beef longissimus eating quality increases up to 20 weeks of storage and is unrelated to meat colour at carcass grading
Authors: Hughes J. M. , McPhail N. G. , Kearney G. , Clarke F. , Warner R. D.
Published: December 2014

Optimal beef meat colour is associated with increased consumer acceptance, whereas dark or pale meat has a reduced desirability. Dark beef also has a variable eating quality and reduced shelf-life. We hypothesised that a poor meat colour at carcass grading would generate an unacceptable eating quality after vacuum-packed chilled storage for up to 20 weeks, due to the unfavourable pH conditions commonly associated with light and dark muscles. At three beef processing plants, beef longissimus muscles from 81 pasture- and grain-fed cattle (mix of Bos taurus and Bos indicus × Bos taurus) were graded at ~24 h post-slaughter for meat colour. The carcasses were allocated to light, medium and dark colour groups, with n = 27 carcasses per colour group. From the 81 carcasses, a total of 162 longissimus lumborum (LL) muscles was collected and half LLs were randomly allocated to three ageing times (2, 12, 20 weeks) within colour group and six half LLs were used per colour group within storage period and plant. Vacuum-packed muscles were stored at –1.0 ± 0.5°C for the designated period and sampled for biochemical and sensory assessments. The effects of colour group, storage week and carcass traits were analysed. Dark muscles had higher pH than the lighter ones (P < 0.05). The carcass trait dentition, feed type and fat depth did not influence the eating quality (P > 0.05). After 2, 12 and 20 weeks of vacuum-packed chilled storage; eating quality was similar for all 3 meat-colour groups (P > 0.05). With increasing storage time, all eating-quality attributes improved (P < 0.001 for all). Lipid oxidation increased with storage time and although values at 20 weeks were slightly above accepted levels for rancidity detection, MQ4 scores indicated that the meat would still be categorised as a three-star product, indicative of the opportunity to store the longissimus lumborum (LL) for this length of time, while maintaining an acceptable eating quality, regardless of meat colour at carcass grading.
Bounded mean oscillation and the uniqueness of active scalar equations
Authors: Azzam Jonas , Bedrossian Jacob
Published: December 2014

We consider a number of uniqueness questions for several wide classes of active scalar equations, unifying and generalizing the techniques of several authors. As special cases of our results, we provide a significantly simplified proof to the known uniqueness result for the 2D Euler equations in

L
1

∩
B
M
O

L^1 \cap BMO

and provide a mild improvement to the recent results of Rusin for the 2D inviscid surface quasi-geostrophic (SQG) equations, which are now to our knowledge the best results known for this model. We also obtain what are (to our knowledge) the strongest known uniqueness results for the Patlak-Keller-Segel models with nonlinear diffusion. We obtain these results via technical refinements of energy methods which are well-known in the

L
2

L^2

setting but are less well-known in the

H
˙

−
1

\dot {H}^{-1}

setting. The

H
˙

−
1

\dot {H}^{-1}

method can be considered a generalization of Yudovich’s classical method and is naturally applied to equations such as the Patlak-Keller-Segel models with nonlinear diffusion and other variants. Important points of our analysis are an

L
p

L^p

-

B
M
O

BMO

interpolation lemma and a Sobolev embedding lemma which shows that velocity fields

v
v

with

∇
v
∈
B
M
O

\nabla v \in BMO

are locally log-Lipschitz; the latter is known in harmonic analysis but does not seem to have been connected to this setting.
Formal constructions in the Brauer group of the function field of a 𝑝-adic curve
Authors: Brussel Eric , Tengan Eduardo
Published: December 2014

We study the relationship between the cohomology of the function field of a curve over a complete discretely valued field and that of the function ring of curves resulting over its residue field. The results are applied to prove the existence of noncrossed product division algebras and indecomposable division algebras of unequal period and index over the function field of any

p
p

-adic curve, generalizing the results and methods of a previous work of the authors and McKinnie.
Irreducible induced representations of Fell bundle 𝐶*-algebras
Authors: Ionescu Marius , Williams Dana
Published: December 2014

We give precise conditions under which irreducible representations associated to stability groups induce to irreducible representations for Fell bundle

C
∗

C^*

-algebras. This result generalizes an earlier result of Echterhoff and the second author. Because the Fell bundle construction subsumes most other examples of

C
∗

C^*

-algebras constructed from dynamical systems, our result percolates down to many different constructions including the many flavors of groupoid crossed products.
Exploring the epidemiology of carbapenem-resistant Gram-negative bacteria in west London and the utility of routinely collected hospital microbiology data
Authors: Freeman R. , Moore L. S. P. , Charlett A. , Donaldson H. , Holmes A. H.
Published: December 2014

Objectives

The objective of this study was to identify carbapenem-resistant organisms using routinely collected local microbiology data and describe the epidemiology of carbapenem resistance in two London teaching hospitals.

Methods

Data on inpatients infected or colonized with Gram-negative organisms between March 2009 and February 2012 were extracted. A computer algorithm was developed incorporating internationally recognized criteria to distinguish carbapenem-resistant organisms. Multivariable analysis was conducted to identify factors associated with infection or colonization with carbapenem-resistant organisms. Binomial regression was performed to detect changes in resistance trends over time.

Results

Yearly incidence of carbapenem resistance was observed to be increasing, with significant increasing trends in Acinetobacter baumannii (47.1% in 2009–10 to 77.2% in 2011–12; P < 0.001) and Enterobacter spp. (2.2% in 2009–10 to 11.5% in 2011–12; P < 0.001). Single-variable and multivariable analysis demonstrated differences in the proportion of carbapenem-resistant isolates across all variables investigated, including age, sex and clinical specialty; in the latter organism-specific niches were identified. Patients in the youngest age group (16–24 years old) had the highest odds of being infected or colonized with carbapenem-resistant isolates of Escherichia coli, Klebsiella spp. or Pseudomonas aeruginosa. Furthermore, proportions of carbapenem-resistant organisms differed between the hospitals.

Conclusions

Carbapenem resistance is an emerging problem within the UK inpatient healthcare setting. This is not an issue confined to the Enterobacteriaceae and fine-resolution surveillance is needed to identify at-risk groups. Regular analysis of routinely collected data can provide insight into the evolving carbapenem-resistance threat, with the ability to inform efforts to prevent the spread of resistance.
Actinomadura rayongensis sp. nov., isolated from peat swamp forest soil
Authors: Phongsopitanun Wongsakorn , Tanasupawat Somboon , Suwanborirux Khanit , Ohkuma Moriya , Kudo Takuji
Published: December 2014

A novel actinomycete strain RY35-68T, isolated from a peat swamp forest soil sample in Rayong Province, Thailand, was characterized using a polyphasic approach. The strain belonged to the genus

Actinomadura

based on morphological and chemotaxonomic characteristics. Cell-wall analysis revealed the presence of meso-diaminopimelic acid and N-acetylmuramic acid in the peptidoglycan layer. The diagnostic sugar in whole-cell hydrolysates was identified as madurose. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The major cellular fatty acids were C16 : 0 and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The genomic DNA G+C content was 73.7 mol%. On the basis of 16S rRNA gene sequence similarity analysis, strain RY35-68T was closely related to the species

Actinomadura atramentaria

JCM 6250T (97.5 %). The value of DNA–DNA relatedness between strain RY35-68T and

A. atramentaria

JCM 6250T was 37.6–42.6 %. On the basis of its phenotypic characteristics and these results mentioned, this strain could be distinguished from the closely related type strain and represents a novel species of the genus

Actinomadura

, for which the name Actinomadura rayongensis sp. nov. (type strain RY35-68T = JCM 19830T = TISTR 2211T = PCU 332T) is proposed.
Crystal structure of [(2R,3R,4S)-3,4-bis(acetyloxy)-5-iodo-3,4-dihydro-2H-pyran-2-yl]methyl acetate
Authors: Zukerman-Schpector Julio , Caracelli Ignez , Stefani Hélio A. , Shamim Anwar , Tiekink Edward R.T.
Published: December 2014

In the title compound, C12H15IO7, the 3,4-dihydro-2H-pyran ring is in a distorted half-boat conformation with the atom bearing the acetyloxy group adjacent to the C atom bearing the methylacetate group lying 0.633 (6) Å above the plane of the remaining ring atoms (r.m.s. deviation = 0.0907 Å). In the crystal, molecules are linked into a supramolecular chain along theaaxis through two C—H...O interactions to the same acceptor carbonyl O atom; these chains pack with no specific intermolecular interactions between them.
Crystal structure of (Z)-4-[1-(4-acetylanilino)ethylidene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one
Authors: Mahfouz Refaat M. , Demircioğlu Zeynep , Abbady Mohamed S. , Büyükgüngör Orhan
Published: December 2014

In the solid state, the title compound, C20H19N3O2, adopts the keto–amine tautomeric form, with the H atom attached to the N atom, which participates in an intramolecular N—H...O hydrogen bond with anS(6) ring motif. The dihedral angles between the pyrazole ring and the phenyl and benzene rings are 3.69 (10) and 46.47 (9)°, respectively. In the crystal, molecules are linked by weak C—H...O hydrogen bonds, generatingC(16) chains propagating in [301]. Weak aromatic π–π stacking interactions [centroid–centroid distances = 3.6123 (10) and 3.6665 (10) Å] link the chains into a three-dimensional network.
Crystal structure ofN-(propan-2-ylcarbamothioyl)benzamide
Authors: Jasinski Jerry P. , Akkurt Mehmet , Mohamed Shaaban K. , Gad Mohamed A. , Albayati Mustafa R.
Published: December 2014

In the crystal structure of the title compound, C11H14N2OS, the six atoms of the central C2N2OS residue are coplanar (r.m.s. deviation = 0.002 Å), which facilitates the formation of an intramolecular N—H...O hydrogen bond, which closes anS(6) loop. The terminal phenyl ring is inclined with respect to the central plane [dihedral angle = 42.10 (6)°]. The most prominent feature of the crystal packing is the formation of {...HNCS}2synthons resulting in centrosymmetric dimers.
Crystal structure of the one-dimensional metal–organic polymercatena-poly[[tris(μ-2,4,6-trimethylbenzoato-κ2O:O′)dizinc]-μ-2,4,6-trimethylbenzoato-κ2O:O′]
Authors: Yamamura Masaki , Nabeshima Tatsuya
Published: December 2014

The title complex, [Zn2(C10H11O2)4]n, has a one-dimensional polymeric structure. The asymmetric unit consists of two zinc atoms bridged by three 2,4,6-trimethylbenzoate anions and one bidentate bridging 2,4,6-trimethylbenzoate anion. The [Zn2(C9H11CO2)3] cluster units are intermolecularly linked to form a one-dimensional polymer, which propagates in the direction of the crystallographicbaxis. The Zn atoms adopt a tetrahedral geometry. The Zn—O bond lengths in the intramolecular bridges are slightly shorter than those in the intermolecular bridges.
Using Grounded Theory Method to Capture and Analyze Health Care Experiences
Authors: Foley Geraldine , Timonen Virpi
Published: December 2014

Objective

Grounded theory (GT) is an established qualitative research method, but few papers have encapsulated the benefits, limits, and basic tenets of doing GT research on user and provider experiences of health care services. GT can be used to guide the entire study method, or it can be applied at the data analysis stage only.

Methods

We summarize key components of GT and common GT procedures used by qualitative researchers in health care research. We draw on our experience of conducting a GT study on amyotrophic lateral sclerosis patients' experiences of health care services.

Findings

We discuss why some approaches in GT research may work better than others, particularly when the focus of study is hard‐to‐reach population groups. We highlight the flexibility of procedures in GT to build theory about how people engage with health care services.

Conclusion

GT enables researchers to capture and understand health care experiences. GT methods are particularly valuable when the topic of interest has not previously been studied. GT can be applied to bring structure and rigor to the analysis of qualitative data.
How Do Rural Households Cope with Economic Shocks? Insights from Global Data using Hierarchical Analysis
Authors: Börner Jan , Shively Gerald , Wunder Sven , Wyman Miriam
Published: December 2014

Unanticipated events can cause considerable economic hardship for poor rural households. Some types of negative shocks, for example weather‐related agricultural losses and vector‐borne diseases, are expected to occur more frequently as a result of climate change. In this paper we measure the role of household‐ and location‐specific characteristics in conditioning behavioural responses to a wide range of idiosyncratic and covariate shocks. We use data from 8,000 rural households in 25 developing countries, compiled in the global database of the Poverty Environment Network. We employ a hierarchical multinomial logit model to identify the importance of characteristics observed at different levels of aggregation on a set of strategies aimed at coping with economic shocks. Results indicate that in response to idiosyncratic shocks, households tend to deplete financial and durable assets, whereas covariate and thus often climate‐related shocks predominantly result in reduced consumption. Households in sites characterised by high asset wealth tend to cope with shocks in a more proactive way than those in sites with average or below average asset wealth, but the role of asset types in conditioning shock responses varies across regions. Our findings have implications for rural development and climate change adaptation strategies.
Total intravenous general anaesthesia vs. spinal anaesthesia for total hip arthroplasty: a randomised, controlled trial
Authors: HARSTEN A. , KEHLET H. , LJUNG P. , TOKSVIG‐LARSEN S.
Published: December 2014

Background

The choice of anaesthetic technique for patients undergoing joint arthroplasty is debatable. The hypothesis of this study was that general anaesthesia would generate a more favourable recovery profile than spinal anaesthesia.

Methods

We randomly allocated 120 patients to either intrathecal bupivacaine or general anaesthesia with target‐controlled infusion of remifentanil and propofol. Length of hospital stay assessed as meeting discharge criteria was the primary outcome parameter. Other outcome parameters were actual time of discharge, pain, use of rescue pain medication, blood loss, length of stay in the post‐operative care unit, dizziness, post‐operative nausea, need of urinary catheterisation and patient satisfaction.

Results

General anaesthesia resulted in slightly reduced length of hospital stay (26 vs. 30 h, P = 0.004), less nausea (P = 0.043) and dizziness (P < 0.001). General anaesthesia patients had higher pain scores during the first two post‐operative hours (P < 0.001) but lower after 6 h compared with the spinal anaesthesia group (P < 0.01 and P < 0.05). General anaesthesia patients had better orthostatic function compared with spinal anaesthesia patients (P = 0.008). Patients in the spinal anaesthesia group fulfilled the discharge criteria from the post‐operative care unit earlier compared with the general anaesthesia patients (P = 0.004). General anaesthesia patients requested a change in the method of anaesthesia for a subsequent operation less often than the spinal anaesthesia patients (5 vs. 13, P = 0.022).

Conclusion

General anaesthesia resulted in a more favourable recovery profile compared with spinal anaesthesia.
Impaired fasting pyloric compliance in gastroparesis and the therapeutic response to pyloric dilatation
Authors: Gourcerol G. , Tissier F. , Melchior C. , Touchais J. Y. , Huet E. , Prevost G. , Leroi A. M. , Ducrotte P.
Published: December 2014

Background

Pyloric pressure and compliance have never been investigated in health nor gastroparesis.

Aim

We hypothesised that pyloric pressure and/or compliance may be altered in gastroparesis.

Methods

Fasting pyloric pressure and compliance were investigated in 21 healthy volunteers (HV), 27 gastroparetic patients (GP) and 5 patients who had undergone oesophagectomy without pyloroplasty as positive controls. Under videofluoroscopic control, pyloric compliance and pressure were measured by the EndoFLIP technique. Gastric emptying half time (T1/2) using 13C–octanoic acid breath test, as well as symptoms and quality of life (GIQLI score) were also monitored.

Results

Mean fasting pyloric compliance was measured at 25.2 ± 2.4 mm²/mmHg in HV, and was lower both in GP (16.9 ± 2.1 mm²/mmHg; P < 0.05) and patients with oesophagectomy (10.9 ± 2.9 mm²/mmHg; P < 0.05). By contrast, fasting pyloric pressure was not different among groups. Fasting pyloric compliance and pressure correlated with T1/2 in GP (R = −0.43; P = 0.04). Fasting pyloric compliance, but not pressure, correlated with symptoms and GIQLI score. Pyloric dilation in 10 GP with low fasting pyloric compliance (<10 mm²/mmHg) increased compliance from 7.4 ± 0.4 to 20.1 ± 4.9 mm²/mmHg (P < 0.01) and improved the GIQLI score from 72.5 ± 5.5 to 89.3 ± 6.1 (P = 0.04).

Conclusion

This prospective study assessed pyloric compliance for the first time, and showed that fasting pyloric compliance is decreased in gastroparetic patients and is associated with T1/2, symptoms and quality of life. This suggests that pyloric compliance may be a new relevant metric in gastroparetic patients, and may be useful to target patients for pyloric dilation or botulinum toxin injection.
An Evaluation of the Effectiveness of Anti‐money Laundering and Anti‐terrorism Financing Legislation: Perceptions of Bank Compliance Officers in Malaysia
Authors: Pok Wee Ching , Omar Normah , Sathye Milind
Published: December 2014

The present study sought to ascertain the perceptions of anti‐money laundering and counter‐financing of terrorism (AML/CFT) compliance officers of banks in Malaysia in order to develop an understanding of how well they understand the risks and how well they have implemented the obligations imposed by the regime. We examine these issues for the first time in the literature via the theory of crying wolf. A structured questionnaire survey of compliance officers of banks in Malaysia was followed by focus group discussions held at the Malaysian Institute of Bankers. We expect that the industry would consider suitable steps to improve the compliance culture, particularly in Islamic banks, and the regulators would watch such banks more diligently. Banks considered avoiding penalties, improving brand image and improving customer perceptions to be the rationale for implementing the AML/CFT legislation. Most conventional bank officers considered their organisations’ compliance culture to be high or very high, while this was not found to be the case in Islamic banks.
Comparison of systematic transrectal biopsy to transperineal magnetic resonance imaging/ultrasound‐fusion biopsy for the diagnosis of prostate cancer
Authors: Borkowetz Angelika , Platzek Ivan , Toma Marieta , Laniado Michael , Baretton Gustavo , Froehner Michael , Koch Rainer , Wirth Manfred , Zastrow Stefan
Published: December 2014

Objectives

To compare targeted, transperineal magnetic resonance imaging (MRI)/ultrasound (US)‐fusion biopsy to systematic transrectal biopsy in patients with previous negative or first prostate biopsy and to evaluate the gain in diagnostic information with systematic biopsies in addition to targeted MRI/US‐fusion biopsies.

Patients and Methods

In all, 263 consecutive patients with suspicion of prostate cancer were investigated. All patients were evaluated by 3‐T multiparametric MRI (mpMRI) applying the European Society of Urogenital Radiology criteria. All patients underwent MRI/US‐fusion biopsy transperineally (mean nine cores) and additionally a systematic transrectal biopsy (mean 12 cores).

Results

In all, 195 patients underwent repeat biopsy and 68 patients underwent first biopsy. The median age was 66 years, median PSA level was 8.3 ng/mL and median prostate volume was 50 mL. Overall, the prostate cancer detection rate was 52% (137/263). MRI/US‐fusion biopsy detected significantly more cancer than systematic prostate biopsy (44% [116/263] vs 35% [91/263]; P = 0.002). In repeat biopsy, the detection rate was 44% (85/195) in targeted and 32% (62/195) in systematic biopsy (P = 0.002). In first biopsy, the detection rate was 46% (31/68) in targeted and 43% (29/68) in systematic biopsy (P = 0.527). In all, 80% (110/137) of biopsy confirmed prostate cancers were clinically significant. For the upgrading of Gleason score, 44% (32/72) more clinically significant prostate cancer was detected by using additional targeted biopsy than by systematic biopsy alone. Conversely, 12% (10/94) more clinically significant cancer was found by systematic biopsy additionally to targeted biopsy.

Conclusions

MRI/US‐fusion biopsy was associated with a higher detection rate of clinically significant prostate cancer while taking fewer cores, especially in patients with prior negative biopsy. Due to a high portion of additional tumours with Gleason score ≥7 detected in addition to targeted biopsy, systematic biopsy should still be performed additionally to targeted biopsy.
Patient experience and satisfaction with Onabotulinumtoxin A for refractory overactive bladder
Authors: Malde Sachin , Dowson Christopher , Fraser Olivia , Watkins Jane , Khan Muhammed S. , Dasgupta Prokar , Sahai Arun
Published: December 2014

Objective

To evaluate the patient experience of our dedicated botulinum toxin A (BTX‐A) service using a validated patient‐reported experience measure (PREM) and assess patient‐reported satisfaction with treatment.

Materials and Methods

The first 100 patients who underwent BTX‐A treatment for refractory idiopathic detrusor overactivity (IDO) in our institution were contacted for telephone interview. They had all been assessed, injected and followed up in a dedicated BTX‐A clinic. Patients were asked to complete a validated PREM – the Client Satisfaction Questionnaire (CSQ‐8) – as well as a questionnaire developed in our department to assess satisfaction with the results of the treatment. Most patients received 200 U OnabotulinumtoxinA (Botox®) via an outpatient local anaesthetic flexible cystoscopy technique.

Results

Complete data was available for 72 patients. In all, 49 patients were continuing to receive BTX‐A treatment while 23 had opted for no further injections. The overall mean (sd) CSQ‐8 satisfaction score was 38.3 (3.3), indicating a high level of patient satisfaction with the service offered in our institution. There was a significant difference in total satisfaction scores between those still receiving BTX‐A (mean score 29.8) and those who have discontinued treatment (mean score 25.1) (P < 0.01). Overall patient satisfaction with the result of the treatment was high with an overall mean (sd) score of 8.6 (2.0) on a visual analogue scale. Of those who had discontinued BTX‐A, most were either using conservative measures only (44%) or had recommenced anticholinergic medications.

Conclusion

Overall patient satisfaction with the dedicated BTX‐A service offered in our institution is high and can result in a positive patient experience. The use of PREMs are advocated in order to fully capture the patient's views of the quality of services and treatments they receive.
Pilomyxoid Astrocytoma (PMA) Shows Significant Differences in Gene Expression vs. Pilocytic Astrocytoma (PA) and Variable Tendency Toward Maturation to PA
Authors: Kleinschmidt‐DeMasters Bette K. , Donson Andrew M. , Vogel Hannes , Foreman Nicholas K.
Published: December 2014

Pilomyxoid astrocytomas (PMAs) manifest a more aggressive clinical course than pilocytic astrocytomas (PAs). Development of effective therapies demands a better biological understanding of PMA. We first conducted gene expression microarray analysis of 9 PMA and 13 PA from infra‐ and supratentorial sites. Unsupervised hierarchical clustering analysis demonstrated that tumors are grouped according to anatomic site, not diagnosis. Gene expression profiles were then contrasted between eight PMAs and six PAs, all supratentorial/hypothalamic/chiasmal. Clinical outcome of PMAs varied, with four out of four patients with diencephalic syndrome succumbing to disease, one of whom showed bulky metastatic leptomeningeal spread at autopsy, with bimodal maturation to PA in some areas and de‐differentiation to glioblastoma in others. A surviving child has undergone multiple surgical debulking, with progressive maturation to PA over time. Ontology‐enrichment analysis identified overexpression in PMAs of extracellular matrix and mitosis‐related genes. Genes overexpressed in PMA vs. PA, ranked according to fold‐change, included developmental genes H19, DACT2, extracellular matrix collagens (COL2A1; COL1A1) and IGF2BP3 (IMP3), the latter previously identified as an adverse prognostic factor in PMA and PA.
ZEB1 Promotes Invasion in Human Fetal Neural Stem Cells and Hypoxic Glioma Neurospheres
Authors: Kahlert Ulf D. , Suwala Abigail K. , Raabe Eric H. , Siebzehnrubl Florian A. , Suarez Maria J. , Orr Brent A. , Bar Eli E. , Maciaczyk Jaroslaw , Eberhart Charles G.
Published: December 2014

Diffuse spread through brain parenchyma and the presence of hypoxic foci rimmed by neoplastic cells are two cardinal features of glioblastoma, and low oxygen is thought to drive movement of malignant gliomas in the core of the lesions. Transcription factors associated with epithelial‐to‐mesenchymal transition (EMT) have been linked to this invasion, and we found that hypoxia increased in vitro invasion up to fourfold in glioblastoma neurosphere lines and induced the expression of ZEB1. Immunohistochemical assessment of 295 surgical specimens consisting of various types of pediatric and adult brain cancers showed that ZEB1 expression was significantly higher in infiltrative lesions than less invasive tumors such as pilocytic astrocytoma and ependymoma. ZEB1 protein was also present in human fetal periventricular stem and progenitor cells and ZEB1 inhibition impaired migration of in vitro propagated human neural stem cells. The induction of ZEB1 protein in hypoxic glioblastoma neurospheres could be partially blocked by the HIF1alpha inhibitor digoxin. Targeting ZEB1 blocked hypoxia‐augmented invasion of glioblastoma cells in addition to slowing them in normoxia. These data support the role for ZEB1 in invasive and high‐grade brain tumors and suggest its key role in promoting invasion in the hypoxic tumor core as well as in the periphery.
Differential factors associated with challenge‐proven food allergy phenotypes in a population cohort of infants: a latent class analysis
Authors: Peters R. L. , Allen K. J. , Dharmage S. C. , Lodge C. J. , Koplin J. J. , Ponsonby A.‐L. , Wake M. , Lowe A. J. , Tang M. L. K. , Matheson M. C. , Gurrin L. C. ,   the HealthNuts study
Published: December 2014

Background

Food allergy, eczema and wheeze are early manifestations of allergic disease and commonly co‐occur in infancy although their interrelationship is not well understood. Data from population studies are essential to determine whether there are differential drivers of multi‐allergy phenotypes. We aimed to define phenotypes and risk factors of allergic disease using latent class analysis (LCA).

Methods

The HealthNuts study is a prospective, population‐based cohort of 5276 12‐month‐old infants in Melbourne, Australia. LCA was performed using the following baseline data collected at age 12 months: food sensitization (skin prick test ≥ 2 mm) and allergy (oral food challenge) to egg, peanut and sesame; early (< 4 months) and late‐onset eczema; and wheeze in the first year of life. Risk factors were modelled using multinomial logistic regression.

Results

Five distinct phenotypes were identified: no allergic disease (70%), non‐food‐sensitized eczema (16%), single egg allergy (9%), multiple food allergies (predominantly peanut) (3%) and multiple food allergies (predominantly egg) (2%). Compared to the baseline group of no allergic disease, shared risk factors for all allergic phenotypes were parents born overseas (particularly Asia), delayed introduction of egg, male gender (except for single egg allergy) and family history of allergic disease, whilst exposure to pet dogs was protective for all phenotypes. Other factors including filaggrin mutations, vitamin D and the presence of older siblings differed by phenotype.

Conclusions and clinical relevance

Multiple outcomes in infancy can be used to determine five distinct allergy phenotypes at the population level, which have both shared and separate risk factors suggesting differential mechanisms of disease.