bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of thermal, rheological, and physical properties of amorphous poly(ethylene terephthalate)/organoclay nanocomposite films
Authors: Gökkurt Tolga , Durmus Ali , Sariboga Vedat , Öksüzömer M. A. Faruk
Published: January 2013

Thermal, rheological, and physical properties of amorphous poly(ethylene terephthalate) (PET)/organoclay nanocomposite films which were successfully prepared with melt processing method using a PET/organoclay masterbatch were studied in detail. Structural and physical properties of the films were characterized by the UV–Vis spectroscopy, XRD and SEM analysis, DSC, DMA, and rheological tests and gas permeability measurements. Cold‐crystallization behavior of the samples was analyzed by the DSC and DMA methods. Aspect ratio of the organoclay layers were determined with the Nielsen and Halpin‐Tsai models based on the gas permeability and DMA data, respectively. It was found that the organoclay reduced the nonisothermal cold‐crystallization rate of PET chains by restricting the segmental motion of the polymer in the solid state. On the other hand, the organoclay enhanced the nonisothermal melt‐crystallization of PET due to the nucleation effect. Aspect ratio (Af) of the clay layers were found to be about 20 by using the gas permeability and DMA data. Aspect ratio value was also confirmed by the analysis of SEM images of the samples. A physical model for the sample microstructure was offered that the stacks with the thickness of 20–30 nm and the lateral size of 400–600 nm, probably consisting of 5–8 layers, were uniformly dispersed in the PET structure. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Investigation of the crystallization behavior of isotactic polypropylene polymerized with different Ziegler‐Natta catalysts
Authors: Kang Jian , Li Jingping , Chen Shaohua , Peng Hongmei , Wang Bin , Cao Ya , Li Huilin , Chen Jinyao , Gai Jinggang , Yang Feng , Xiang Ming
Published: January 2013

Detailed characterization of the crystallization behavior is important for obtaining better structure property correlations of the isotactic polypropylene (iPP), however, attributed to the complexity in ZN‐iPP polymerization, the relationship between crystallization behavior and the stereo‐defect distribution of iPP is still under debate. In this study, the crystallization kinetics of the primary nucleation, crystal growth and overall crystallization of two iPP samples (PP‐A and PP‐B) with nearly same average isotacticity but different stereo‐defect distribution (the stereo‐defect distribution of PP‐B is more uniform than PP‐A) were investigated. The results of isothermal crystallization kinetics showed that the overall crystallization rate of PP‐A was much higher than that of PP‐B; but the analysis of self‐nucleation isothermal crystallization kinetics and the polarized optical microscopy (POM) observation indicated that the high overall crystallization rate of PP‐A was attributed to the high primary nucleation rate of the resin. The stereo‐defect distribution plays an important role in determining both the nucleation kinetics and crystal grow kinetics, and thus influence the overall crystallization kinetics. A more uniform distribution of stereo‐defects restrains the crystallization rate of iPP, moreover, it has more influence on nucleation kinetics, comparing with the crystal growth. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
A simple, inexpensive, real‐time interferometric cure monitoring system for optically cured polymers
Authors: Schwerzel Robert E. , Jariwala Amit S. , Rosen David W.
Published: January 2013

Optically cured polymers play a crucial role in many commercial applications, ranging from UV‐cured inks, coatings, and dental fillings to the optical fabrication of three‐dimensional prototypes by means of stereolithography. However, our understanding of the detailed processes that occur in the curing of these materials is often limited by the practical difficulty of observing the cure process in real time, under “real‐world” conditions. This article reports the simple implementation of a free‐space Mach‐Zehnder interferometer that can be constructed inexpensively from readily available components, and demonstrates its utility in monitoring the UV curing of a typical acrylate photopolymer system in real time. In particular, it is shown that this system can sensitively track the induction period, the light‐induced photopolymerization reaction, and the subsequent dark reaction that continues after the irradiation has been halted. This Interferometric Cure Monitor, or “ICM,” thus provides a valuable addition to other analytical methods, both for improving the quality control of existing commercial processes and for aiding the development of improved photopolymer formulations. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Purification of long helical capsid of newcastle disease virus from Escherichia coli using anion exchange chromatography
Authors: Yap Chee Fai , Tan Wen Siang , Sieo Chin Chin , Tey Beng Ti
Published: January 2013

NPΔc375 is a truncated version of the nucleocapsid protein of Newcastle disease virus (NDV) which self‐assembles into a long helical structure. A packed bed anion exchange chromatography (PB‐AEC), SepFastTM Supor Q pre‐packed column, was used to purify NPΔc375 from clarified feedstock. This PB‐AEC column adsorbed 76.2% of NPΔc375 from the clarified feedstock. About 67.5% of the adsorbed NPΔc375 was successfully eluted from the column by applying 50 mM Tris‐HCl elution buffer supplemented with 0.5 M NaCl at pH 7. Thus, a recovery yield of 51.4% with a purity of 76.7% which corresponds to a purification factor of 6.5 was achieved in this PB‐AEC operation. Electron microscopic analysis revealed that the helical structure of the NPΔc375 purified by SepFastTM Supor Q pre‐packed column was as long as 490 nm and 22–24 nm in diameter. The antigenicity of the purified NPΔc375 was confirmed by enzyme‐linked immunosorbent assay. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 564–567, 2013
Model for Conformational Relaxation of Flexible Conjugated Polymers: Application to p‐Phenylenevinylene Trimers in Nonpolar Solvents
Authors: Galvão Adelino M. , Di Paolo Roberto E. , Maçanita António L. , Naqvi K. Razi
Published: January 2013

Photoexcitation of flexible conjugated polymers is invariably followed by a fast conformational/torsional relaxation towards a configuration favouring coplanarity of the conjugated segments. In general, the experimental relaxation rate constant (kCR) depends on the solvent viscosity (η) and temperature (T), and is not proportional to T/η. A theory capable of explaining the observed dependence of kCR on T and η over a wide range of these variables is not available. This gap is filled here by presenting a stochastic model that includes the participation of the oligomer side chain in storing and dissipating the stresses induced by photoexcitation. The model is able to account for the softening of solute–solvent interactions and its predictions are found to be in excellent agreement with the observed relaxation rate constants of a series of substituted p‐phenylenevinylene trimers [ChemPhysChem 2009, 10, 448–454] on T, η and the size of the side‐chains.
Emission of Ultrashort Electromagnetic Pulses from Electron Bunches Formed and Accelerated by Laser Beams with Tilted Amplitude Fronts
Authors: Galkin A.L. , Korobkin V.V. , Romanovsky M.Yu. , Shiryaev O.B. , Trofimov V.A.
Published: January 2013

The dynamics of an electron in a standing wave generated by a pair of counterpropagating linearly polarized relativistically intense laser pulses and the emission of electromagnetic radiation by the electron are analyzed. The pulses are assumed to have tilted amplitude fronts and asymmetric focal spots. The analysis of the dynamics is performed by solving numerically the Newton equation with the corresponding Lorentz force, and the emission of radiation is simulated based on the Lienard‐Wiechert potentials. The electrons are accelerated by the direct action of the standing wave field and are shown to form a small short bunch. For relativistic intensities, the energies gained by the electrons reach several GeV. It is demonstrated that the radiation emitted by the electrons in the bunch is a single electromagnetic pulse confined to a narrow solid angle and having an attosecond duration. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Generation of Quantum Beams in Large Clusters Irradiated by Super‐Intense, High – Contrast Femtosecond Laser Pulses
Authors: Faenov A. Ya. , Pikuz T. A. , Fukuda Y. , Skobelev I. Yu. , Nakamura T. , Bulanov S. V. , Hayashi Y. , Kotaki H. , Pirozhkov A. S. , Kawachi T. , Chen L. M. , Zhang L. , Yan W. C. , Yuan D. W. , Mao J. Y. , Wang Z. H. , Ma J. L. , Fortov V. E. , Kato Y. , Kando M.
Published: January 2013

A short review of our experimental studies on generation of photon and particle beams in submicron clusters irradiated by intense, high‐contrast (∼ 108–1010) femtosecond laser pulses is presented. It is shown that highlyefficient laser‐cluster interaction allows creating bright sources of X‐ray, high‐energy electron and ion beams. The examples of applications of femtosecond‐laser‐produced cluster plasmas (FLPCP) for X‐ray and ion beams radiography are presented. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Laser Pulse Parameters on the Properties of e–e+ Plasmas Created from Vacuum
Authors: Blaschke D. B. , Kämpfer B. , Panferov A. D. , Prozorkevich A. V. , Smolyansky S. A.
Published: January 2013

We use the low density approximation within the kinetic theory approach to vacuum creation of an e–e+ pair plasma (EPPP) in a strong laser field in order to investigate the dependence of the observed EPPP on the form and parameters of a single laser pulse. The EPPP distribution function is calculated for an arbitrary time dependence of the electric field in the multiphoton domain (adiabaticity parameter γ > 1). The dependence on the field strength, the form and spectrum of the field pulse is investigated on the basis both analytical and numerical methods. The obtained results can be useful for examining some observable secondary processes associated with the dynamical Schwinger effect. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interaction of Ultra High Intensity Laser Pulse with Structured Target and Fast Particle Generation in a Stable Mode
Authors: Andreev A. A. , Platonov K. Yu.
Published: January 2013

It is shown that the relief structure with optimum parameters can significantly increase the short‐pulse laser absorption, which is connected with the enhancement of moving electrons between relief ledges. Analytical modeling and numerical simulations confirm this argumentation. In the considered cases, degradation of a structure by a laser pre‐pulse is the most important factor and for this scheme to work, one needs a very high‐contrast laser‐pulse and a nanosecond laser pre‐pulse duration. The limitation on laser pulse duration is not so strong because after destruction of a first relief a secondary dynamic structure of ion density appears. Thus, high absorption connected with a relief existence continues during a long time that gives a possibility for structure targets to be more efficient compared to a plane one. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reaching Vacuum Harmonic Generation and Approaching the Schwinger Limit with X‐Rays
Authors: Borisov A. B. , McCorkindale J. C. , Poopalasingam S. , Longworth J. W. , Rhodes C. K.
Published: January 2013

The derivation of an elementary figure of merit shows that the attainment of ultrahigh intensities suitable for probing the dynamics of the vacuum state is significantly facilitated by the use of coherent x‐ray sources in the kiloelectronvolt regime. For the Xe(M) system at 𝒽ω ∼ 1 keV, estimates indicate that an intensity sufficient for the observation of vacuum harmonic generation (∼ 1027 W/cm2) can be reached with pulse energies in the 10 – 100 mJ range. Recent measurements indicate that x‐ray yield of Xe(M) 4f → 3d emission from Xe clusters in self‐trapped plasma channels produced with femtosecond 248 nm pulses can be readily extended into this range. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and Characterization of Zinc Ketoiminate and Zinc Alkoxide–/Phenoxide–Ketoiminate Complexes
Authors: Di Iulio Carlo , Middleton Mathew , Kociok‐Köhn Gabriele , Jones Matthew D. , Johnson Andrew L.
Published: January 2013

Dimeric methylzinc ketoiminate complexes bis{4‐[(2,6‐diisopropylphenyl)imido]pentan‐1‐one}methylzinc, [{L1}ZnMe]2, and bis{1‐phenyl‐3[(2,6‐diisopropylphenyl)imido]butan‐1‐one}methylzinc, [{L2}ZnMe]2 have been synthesized and completely characterized along with the homoleptic zinc complex bis{1‐phenyl‐3[(2,6‐diisopropylphenyl)imido]butan‐1‐one}zinc, [{L2}2Zn] by means of single‐crystal X‐ray structure analysis and NMR spectroscopy. The related dimeric zinc phenoxide–ketoiminate complexes [{L3}Zn]2·(dmso)2, [{L4}Zn]2·(dmso)2, [{L5}Zn]2·(dmso)2, [{L6}Zn]2·(dmso)2 and [{L4}Zn]2·(hmpa)2 (dmso = dimethyl sulfoxide; hmpa = hexamethylphosphoramide) have also been synthesized along with the tetrameric zinc alkoxide–ketoiminate complex [{L7}Zn]4. In preliminary studies the complexes described in this report were assessed for their activity in the ring‐opening polymerization of rac‐lactide, either in the solution state (in the presence of benzyl alcohol initiator), or under industrially preferred melt conditions (130 °C no solvent). It could be shown that these compounds are able to act as initiators for lactide polymerization, with molecular weights (Mn) of up to 102050 g/mol.
Synthesis, Structure and Catalytic Properties of Dinuclear MoVI Complexes with Ditopic Diaminotetraphenols
Authors: Riisiö Antti , Lehtonen Ari , Hänninen Mikko M. , Sillanpää Reijo
Published: January 2013

MoVI complexes with novel ditopic diaminotetraphenol ligands have been prepared by using a one‐pot procedure in methanol or DMSO with [MoO2(acac)2] (acac = acetylacetonate) as the molybdenum source. The complexes were characterised with X‐ray diffraction, NMR spectroscopic studies, elemental analysis and IR spectroscopy. In the solid state, the compounds represent either a rodlike molecular or oxido‐bridged polymeric structure. The catalytic activity of the complexes was investigated by oxidising benzyl alcohol and 1‐phenylethanol with hydrogen peroxide to the corresponding aldehyde and ketone, respectively. Furthermore, the catalytic activity was surveyed also in epoxidation of cyclooctene.
Spin‐State Tuning in Iron(II) Triazamacrocyclic Complexes
Authors: Tolla Azam S. , Banerjee Atanu , Stjepanovic Slavica , Li Jia , Brennessel William W. , Loloee Reza , Chavez Ferman A.
Published: January 2013

The structures of [FeII(tacn)2](OTf)2·DMF (1·DMF), [FeII(tacd)2](OTf)2 (2), and [FeII(tacud)2](OTf)2 (3) (OTf = triflate, tacn = 1,4,7‐triazacyclononane, tacd = 1,4,7‐triazacyclodecane, tacud = 1,4,8‐triazacycloundecane) are reported. In the solid state, compounds 1 and 2 exhibit temperature‐dependent gradual and reversible one‐step spin crossover between the high‐spin (S = 2) and low‐spin (S = 0) states with estimated spin‐conversion equilibria (T1/2) of 330 and 320 K, respectively. Compound 1 exhibits somewhat reversible magnetic behavior during the heating and cooling cycle, whereas 2 is more reversible. Compound 2 is only the third example of a spin‐crossover compound possessing secondary amine ligands exclusively. Complex 3 is high spin at the temperatures measured. Systematic comparison of the properties of 1–3 indicates that the structural–magnetic properties correlate with the ligand‐donor strength. There is also a close correlation with the room‐temperature solution spin state and E1/2 in acetonitrile for these compounds.
PHYSICAL ACTIVITY AND HEALTH OUTCOMES: EVIDENCE FROM CANADA
Authors: Humphreys Brad R. , McLeod Logan , Ruseski Jane E.
Published: January 2013

Health production models include participation in physical activity as an input. We investigate the relationship between participation in physical activity and health using a bivariate probit model. Participation is identified with an exclusion restriction on a variable reflecting sense of belonging to the community. Estimates based on data from Cycle 3.1 of the Canadian Community Health Survey indicate that participation in physical activity reduces the reported incidence of diabetes, high blood pressure, heart disease, asthma, and arthritis as well as being in fair or poor health. Increasing the intensity above the moderate level and frequency of participation in physical activity appears to have a diminishing marginal impact on adverse health outcomes. Our results provide support for guidelines about engaging in exercise regularly to achieve health benefits. Copyright © 2013 John Wiley & Sons, Ltd.
Teacher Scaffolding of Academic Language in an Advanced Placement U.S. History Class
Authors: Gritter Kristine , Beers Scott , Knaus Robert W.
Published: January 2013

This article examines teacher scaffolding of academic language in an Advanced Placement United State History (APUSH) course throughout a school year for one student who received a perfect score on the end of year APUSH exam. Data includes four months of observation of teacher instructional strategies to scaffold student writing and vignettes of student writing with marked academic language change over time. We conclude that to construct effective arguments in writing, students need narrative continuity across the big ideas of history and sophisticated language to convey this knowledge in their writing. Teachers can scaffold this as part of their instruction and evidence of success can appear in student writing.
Non‐linear optical microscopy of kidney tumours
Authors: Galli Roberta , Sablinskas Valdas , Dasevicius Darius , Laurinavicius Arvydas , Jankevicius Feliksas , Koch Edmund , Steiner Gerald
Published: January 2013

The unregulated cancer cell growth leads to strong alterations in morphology and composition of the tissue. The combination of coherent anti‐Stokes Raman scattering, two‐photon excited fluorescence and second harmonic generation enables a high resolution imaging with strong information on tissue composition and can then provide useful information for tumour diagnosis. Here we present the potential of multimodal non‐linear microscopy for imaging of renal tumours. Using cryosections of human oncocytoma and carcinoma, the method gave a detailed insight in cancer morphology and composition, enabling to discern between normal kidney tissue, tumour and necrosis. Several features significant for the diagnosis were clearly visualised without use of any staining. Translation of this method in clinical pathology will greatly improve speed and quality of the analyses. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The association between fracture site and obesity in men: A population-Based cohort study
Authors: Premaor Melissa O , Compston Juliet E , Fina Avilés Francesc , Pagès-Castellà Aina , Nogués Xavier , Díez-Pérez Adolfo , Prieto-Alhambra Daniel
Published: January 2013

A site-dependent association between obesity and fracture has been reported in postmenopausal women. In this study we investigated the relationship between body mass index (BMI) and fracture at different skeletal sites in older men (≥65 years). We carried out a population-based cohort study using data from the Sistema d‘Informació per al Desenvolupament de l‘Investigació en Atenció Primària (SIDIAPQ) database. SIDIAPQ contains the primary care and hospital admission computerized medical records of >1300 general practitioners (GPs) in Catalonia (Northeast Spain), with information on a representative 30% of the population (>2 million people). In 2007, 186,171 men ≥65 years were eligible, of whom 139,419 (74.9%) had an available BMI measurement. For this analysis men were categorized as underweight/normal (BMI < 25 kg/m2, n = 26,298), overweight (25 ≤ BMI < 30 kg/m2, n = 70,851), and obese (BMI ≥ 30 kg/m2, n = 42,270). Incident fractures in the period 2007 to 2009 were ascertained using International Classification of Diseases, 10th edition (ICD-10) codes. A statistically significant reduction in clinical spine and hip fractures was observed in obese (relative risk [RR], 0.65; 95% confidence interval [CI], 0.53–0.80 and RR, 0.63; 95% CI, 0.54–0.74, respectively), and overweight men (RR, 0.77; 95% CI, 0.64–0.92 and RR, 0.63; 95% CI 0.55–0.72, respectively) when compared with underweight/normal men. Additionally, obese men had significantly fewer wrist/forearm (RR, 0.77; 95% CI, 0.61–0.97) and pelvic (RR, 0.44; 95% CI, 0.28–0.70) fractures than underweight/normal men. Conversely, multiple rib fractures were more frequent in overweight (RR, 3.42; 95% CI, 1.03–11.37) and obese (RR, 3.96; 95% CI, 1.16–13.52) men. In this population-based cohort of older men, obesity was associated with a reduced risk of clinical spine, hip, pelvis, and wrist/forearm fracture and increased risk of multiple rib fractures when compared to normal or underweight men. Further work is needed to identify the mechanisms underlying these associations.
In Obese Postmenopausal Women, Bone Microarchitecture and Strength Are Not Commensurate to Greater Body Weight: The Os des Femmes de Lyon (OFELY) Study
Authors: Sornay-Rendu Elisabeth , Boutroy Stephanie , Vilayphiou Nicolas , Claustrat Bruno , Chapurlat Roland D
Published: January 2013

Obesity is associated with higher areal bone density (aBMD) but its protective effect on the risk of fracture is controversial. We aimed to analyze bone microarchitecture and biomechanical properties in obese (OB) postmenopausal French women compared with normal weight (NW) women. A matched case-control study from the Os des Femmes de Lyon (OFELY) cohort was conducted in 63 OB women (body mass index [BMI] > 30, mean age 69 ± 8 years) age-matched with 126 NW women (19 ≤ BMI ≤ 25). Bone architecture was measured with high-resolution pQCT at the distal radius and tibia and bone strength was assessed by micro–finite element analysis (µFEA). aBMD, total body fat mass (FM) and lean mass (LM) were measured by dual-energy X-ray absorptiometry (DXA). aBMD was 15% higher at the total hip in OB compared with NW women. At the radius, OB had 13% and 14% higher volumetric total and trabecular bone densities, 11% higher cortical thickness, 13% greater trabecular number, and 22% lower distribution of trabecular separation compared with NW (p adjusted for height, physical activity, and medication use, <0.01 for all). Differences of a similar magnitude were found at the distal tibia. At both sites, µFEA showed significant higher values of bone strength in OB compared to controls. After normalizing values for individual body weight, we observed that all the parameters were relatively lower in OB compared to NW women. The increase of FM was fourfold greater than the increase of LM in OB. The effect of FM on bone parameters was more pronounced at the tibia compared to the non–weight-bearing site. Nevertheless, the coefficients of correlation were about one-half of those of LM for the biomechanical parameters. We conclude that higher absolute values of bone densities, cortical and trabecular architecture, and strength indices were not in proportion to the excess of BMI and particularly of FM in obese postmenopausal French women.
Randomized controlled trials in therapeutic apheresis
Authors: Winters Jeffrey L.
Published: January 2013

The literature on the use of therapeutic apheresis is often criticized for the preponderance of low to very low quality evidence. Shehata et al. examined the apheresis literature published between 1976 and 1999 and found a lack of randomized controlled trials with those identified demonstrating significant limitations. To determine if this has improved, MEDLINE was searched for randomized controlled therapeutic apheresis trials. In addition, the Clinicaltrials.gov database was also searched for actively recruiting randomized controlled therapeutic apheresis trials. The results revealed that the total and average number of publications per year examining therapeutic apheresis has increased substantially in the period 2000–2012 compared to 1976–1999. This was associated with a small increase in the average number of randomized controlled trials reported each year, but these trials represented a smaller percentage of the therapeutic apheresis literature published compared to the 1976–1999 time range. The reported trials continued to have very small numbers of enrolled patients raising questions about their ability to determine whether apheresis represents an effective therapy. Finally, according to the Clinicaltrials.gov database, a small number of randomized controlled trials of therapeutic apheresis are enrolling patients. Despite an increasing emphasis on evidence‐based medicine and the need for quality randomized controlled clinical trials, there is still a lack of such trials when it comes to therapeutic apheresis. There continues to be a need for more and better designed randomized trials in therapeutic apheresis. J. Clin. Apheresis 28:48–55, 2013. © 2013 Wiley Periodicals, Inc.
Tiling 3‐Uniform Hypergraphs With
Authors: Czygrinow Andrzej , DeBiasio Louis , Nagle Brendan
Published: January 2013

Let denote the hypergraph consisting of two triples on four points. For an integer n, let denote the smallest integer d so that every 3‐uniform hypergraph G of order n with minimum pair‐degree contains vertex‐disjoint copies of . Kühn and Osthus (J Combin Theory, Ser B 96(6) (2006), 767–821) proved that holds for large integers n. Here, we prove the exact counterpart, that for all sufficiently large integers n divisible by 4,

math imageA main ingredient in our proof is the recent “absorption technique” of Rödl, Ruciński, and Szemerédi (J. Combin. Theory Ser. A 116(3) (2009), 613–636).
Quantitative assessment of systolic and diastolic left ventricular twist using Fourier Analysis of Stimulated echoes (FAST) and CSPAMM
Authors: Reyhan Meral , Ennis Daniel B.
Published: January 2013

Purpose:

To evaluate Fourier Analysis of Stimulated echoes (FAST) and CSPAMM for the quantification of left ventricular (LV) systolic and diastolic function and compare it with the previously validated FAST+SPAMM technique.

Materials and Methods:

LV short‐axis tagged images were acquired with CSPAMM and SPAMM in healthy volunteers (n = 13). The FAST method was used to automatically estimate LV systolic and diastolic twist parameters from rotation of the stimulated echo and stimulated anti‐echo about the middle of k‐space subsequent to ∼3 min of user interaction.

Results:

There was no significant difference between measures obtained for FAST+CSPAMM and FAST+SPAMM for mean peak twist (13.5 ± 2.7° versus 11.9 ± 4.0°), torsion (3.4 ± 0.8°/cm versus 2.9 ± 1.0°/cm), twisting rate (76.8 ± 22.2°/s versus 68.2 ± 23.4°/s), untwisting rate (−102.7 ± 24.6°/s versus −106.6 ± 32.4°/s), normalized untwisting rate (−7.9 ± 2.2/s versus −9.9 ± 4.4/s), and time of peak twist (279 ± 23 ms versus 293 ± 25 ms) (all P > 0.01). FAST+CSPAMM also provided measures of duration of untwisting (148 ± 21 ms) and the ratio of rapid untwist to peak twist (0.8 ± 0.3). Bland‐Altman analysis of FAST+CSPAMM and FAST+SPAMM twist data demonstrates excellent agreement with a bias of 1.1° and 95% confidence intervals of [−3.3°, 5.2°].

Conclusion:

FAST+CSPAMM is a semi‐automated method that provides a quick and quantitative assessment of LV systolic and diastolic twist and torsion. J. Magn. Reson. Imaging 2013;37:678–683. © 2013 Wiley Periodicals, Inc.
In vivo comparison of myocardial T1 with T2 and T2* in thalassaemia major
Authors: Feng Yanqiu , He Taigang , Carpenter John‐Paul , Jabbour Andrew , Alam Mohammed Harith , Gatehouse Peter D. , Greiser Andreas , Messroghli Daniel , Firmin David N. , Pennell Dudley J.
Published: January 2013

Purpose:

To compare myocardial T1 against T2 and T2* in patients with thalassemia major (TM) for myocardial iron characterization.

Materials and Methods:

A total of 106 TM patients (29 ± 10 years; 58 males) were studied on a 1.5 Tesla scanner using dedicated T1, T2*, and T2 relaxometry sequences. A single mid‐ventricular short axis slice was acquired within a breath‐hold.

Results:

In patients with myocardial iron overload (T2* < 20 ms; n = 52), there were linear correlations between T2 and T2* (r = 0.82; P = 0.0), and between T1 and T2* (r = 0.83; P = 0.0). In patients with no myocardial iron (n = 54), T2* values were scattered with no significant correlation against T2 or T1. For all patients (n = 106) there was a strong linear correlation (r = 0.93; P = 0.0) between myocardial T1 and T2.

Conclusion:

In patients with iron overload, myocardial T2 and T1 are correlated with T2*. In patients with low or normal myocardial iron concentration, other factors become dominant in affecting T2* values as shown by scattered T2* data. Myocardial T1 correlates linearly with T2 measurements in all patients suggesting that these two relaxation parameters avoid extrinsic magnetic field inhomogeneity effects and may potentially provide improved myocardial tissue characterization. J. Magn. Reson. Imaging 2013;38:588–593. © 2013 Wiley Periodicals, Inc.
3D coronary MR angiography at 1.5 T: Volume‐targeted versus whole‐heart acquisition
Authors: Jin Hang , Zeng Meng‐Su , Ge Mei‐Ying , Yun Hong , Yang Shan
Published: January 2013

Purpose:

To compare volume‐targeted acquisition with whole‐heart acquisition in 1.5‐T free‐breathing 3D coronary magnetic resonance angiography (MRA) with parallel imaging.

Materials and Methods:

The major coronary arteries were imaged in 36 subjects using the whole‐heart and volume‐targeted acquisitions with comparable imaging parameters. The quantitative and semiquantitative data derived from these two acquisition methods were analyzed statistically, with P < 0.05 considered significant.

Results:

Both the right coronary artery (RCA) / left circumflex artery (LCX)‐ and the left main (LM) / left anterior descending (LAD)‐targeted acquisitions had similar results in navigator efficiencies and apparent signal‐to‐noise ratio (SNR) in comparison with whole‐heart acquisition. Apparent contrast‐to‐noise ratio (CNR) of the volume‐targeted imaging was significantly higher than that of the whole‐heart imaging. The imaging time required for a whole‐heart scan was significantly longer than each of the RCA/LCX‐ and LM/LAD‐targeted acquisitions. However, the sum of scanning times derived from volume‐targeted imaging was significantly longer than that of whole‐heart acquisition. Both RCA/LCX‐ and LM/LAD‐targeted acquisition yield higher vessel sharpness and overall image quality in comparison with whole‐heart acquisition. The lengths of the major coronary arteries were not significantly different for the whole‐heart and volume‐targeted approaches. The whole‐heart method was obviously superior to the volume‐targeted method in terms of visualization of the posterior descending artery.

Conclusion:

For current 1.5‐T navigator coronary MRA, volume‐targeted and whole‐heart acquisitions have their own advantages and the choice of methods may vary in accordance with the different aims of clinical practice. J. Magn. Reson. Imaging 2013;38:594–602. © 2013 Wiley Periodicals, Inc.
Postoperative evaluation of superficial temporal artery‐middle cerebral artery bypass using an MR angiography technique with combined white‐blood and black‐blood sequences
Authors: Tsuchiya Kazuhiro , Imai Masamichi , Nitatori Toshiaki , Kimura Tokunori
Published: January 2013

Purpose:

To assess the performance of the hybrid of opposite‐contrast MR angiography (HOP MRA) technique, which combines flow dephasing and compensating sequences, in the postoperative evaluation of superficial temporal artery (STA)‐middle cerebral artery (MCA) bypass.

Materials and Methods:

Both 3D‐HOP MRA and 3D‐time‐of‐flight (TOF) MRA at 1.5 Tesla were performed in 19 patients after STA‐MCA bypass. The two techniques were visually evaluated to compare the visualization of distal MCA branches and the length and number of depicted recipient MCA branches. Additionally, for the depicted recipient MCA branches, the contrast‐to‐noise ratio (CNR) and length were compared between the two techniques.

Results:

The 3D‐HOP MRA provided better visualization of the recipient MCA branches than 3D‐TOF MRA in 10 of the 19 patients, while the depicted recipient MCA branches were longer on 3D‐HOP MRA than on 3D‐TOF MRA in 9 patients. Although not statistically significant, the average number of depicted recipient branches by 3D‐HOP MRA (2.16) was greater than that by 3D‐TOF MRA (1.79). 3D‐HOP MRA was significantly superior to 3D‐TOF MRA in both CNR (119.0 versus 74.3) and length of the recipient MCA branches (72.0 versus 49.9 pixels).

Conclusion:

3D‐HOP MRA is superior to 3D‐TOF MRA for the detailed evaluation of STA‐MCA bypass. J. Magn. Reson. Imaging 2013;38:671–676. © 2013 Wiley Periodicals, Inc.
Molecular characterization of norovirus GII strains identified in Albania
Authors: Donia Domenica , Cenko Fabian , Divizia Maurizio
Published: January 2013

Noroviruses (NoVs) are considered as the leading cause of diarrheal diseases in all groups of age. In the last decade the number of NoV outbreaks worldwide is increasing. Data published by the systems of NoV surveillance show the GII.4 strain as the human predominant genotype circulating worldwide and new genetic variants of GII.4 were associated with epidemic events. In Albania the economy transformation has damaged significantly the environment and a large circulation of enteric viruses was reported in the past with the presence of NoV among the genotyped strains. This study aimed to characterize, by molecular analysis, the NoV GII strains detected in Albania during two time periods: in 2010 from the outbreak occurred in Ballsh and in 2002–2003 from sporadic cases of diarrhoea. A total of 21 Nov GII strains were characterized. The NoV GII.4 was genotyped more frequently and it was related closely to the pandemic variants recorded in GenBank. During 2002–2003, six NoV GII recombinant strains have been characterized. J. Med. Virol. 85:731–736, 2013. © 2013 Wiley Periodicals, Inc.
Hepatitis E virus isolated from rabbits is genetically heterogeneous but with very similar antigenicity to human HEV
Authors: Wang Song , Dong Chen , Dai Xing , Cheng Xianfeng , Liang Jiuhong , Dong Min , Purdy Michael A. , Meng Jihong
Published: January 2013

Rabbit hepatitis E virus (HEV) in China may represent a novel HEV genotype, although no consensus has been reached. It is unclear whether the ORF2 capsid protein containing the immunodominant epitopes from rabbit HEV differs from those of human HEV. In this study, 661 bile samples collected from domestic rabbits in Jiangsu province, eastern China were amplified by RT‐nPCR using a set of HEV universal ORF2 primers. All 42 (6.4%) positive PCR products were sequenced. Phylogenetic analysis using the ORF2 sequences of 557 bp in length showed the Jiangsu isolates were separate from HEV genotypes 1, 2, 3, 4, avian HEV and rat HEV, and clustered together with rabbit HEV sequences. These 42 isolates were divided into five branches including two newly identified in the present study. Comparison with rabbit HEV sequences from China available in GenBank, using a 298 bp ORF2 segment, showed these sequences clustered together into a unique rabbit HEV clade, and were divided into eight sub‐branches with high genetic heterogeneity. In addition, 267 serum samples collected from domestic rabbits, serial serum samples from two rhesus monkeys experimentally infected with HEV genotype 1 or 4, and serial serum samples from two New‐Zealand rabbits infected experimentally with rabbit HEV were tested simultaneously by EIA using recombinant truncated ORF2 capsid proteins derived from rabbit and human HEV. The virtually identical results obtained suggest that rabbit and human HEV ORF2 antigens contain very similar immunodominant epitopes. All these data are helpful to identify the biological characteristics of the newly identified rabbit HEV. J. Med. Virol. 85:627–635, 2013. © 2013 Wiley Periodicals, Inc.
Self‐calibration three‐dimensional light field display based on scalable multi‐LCDs
Authors: Peng Yifan , Li Haifeng , Wang Rui , Zhong Qing , Han Xiang , Cao Zisheng , Liu Xu
Published: January 2013

Approach to achieve self‐calibration three‐dimensional (3D) light field display is investigated in this paper. The proposed 3D light field display is constructed up on spliced multi‐LCDs, lens and diaphragm arrays, and directional diffuser. The light field imaging principle, hardware configuration, diffuser characteristic, and image reconstruction simulation are described and analyzed, respectively. Besides the light field imaging, a self‐calibration method is proposed to improve the imaging performance. An image sensor is deployed to capture calibration patterns projected onto and then reflected by the polymer dispersed liquid crystal film, which is attached to and shaped the diffuser. These calibration components are assembled with the display unit and can be switched between display mode and calibration mode. In the calibration mode, the imperfect imaging relations of optical components are captured and calibrated automatically. We demonstrate our design by implementing the prototype of proposed 3D light field display by using modified off‐the‐shelf products. The proposed approach successfully meets the requirement of real application on scalable configuration, fast calibration, large viewing angular range, and smooth motion parallax.
Morale as a Moderator of the Combat Exposure‐PTSD Symptom Relationship
Authors: Britt Thomas W. , Adler Amy B. , Bliese Paul D. , Moore DeWayne
Published: January 2013

We examined morale as a moderator of the relationship between combat exposure and posttraumatic stress disorder (PTSD) symptoms in a longitudinal study of U.S. soldiers who had participated in a deployment to Iraq. Soldiers (N = 636) completed assessments at 4 (Time 1) and 10 (Time 2) months following their combat deployment. Combat exposure (both breadth and perceived stressfulness), morale, and PTSD symptoms were assessed at Time 1, and PTSD symptoms were assessed again at Time 2. Results of multivariate multiple regressions revealed that morale at Time 1 interacted with both the breadth and stressfulness of combat exposure to predict PTSD symptoms at both Time 1 and Time 2, even when partialling out the effect of unit support. The slope of the given combat exposure and PTSD symptoms relationship was weaker when reports of morale were higher (with the effect size of the interaction ranging from .01 to .04). The results suggest that morale may buffer soldiers from the negative consequences of combat stressors.
A 7‐Year Follow‐Up Study on the Mental Health of North Korean Defectors in South Korea
Authors: Jeon Woo‐Taek , Eom Jin‐Sup , Min Sung Kil
Published: January 2013

This study was conducted to describe the relationship of past trauma and current stress on the mental health of North Korean (NK) defectors living in South Korea 7 years after a baseline assessment. Of the 200 who participated in the initial study, 106 participated in follow‐up. Previous data regarding past traumatic events experienced in North Korea and during defection, past posttraumatic stress disorder (PTSD), and their current stress levels were correlated with the participants’ current mental health status including depression, anxiety, and PTSD. The rate of PTSD in the sample and the scores on the PTSD symptom scale decreased significantly from the baseline. The participants’ current mental health was negatively related to previous traumatic experiences in North Korea and past symptoms of PTSD, but unrelated to previous trauma experienced during defection. In addition, although current mental health was negatively related to only current culture‐related stress, it was unrelated to the level of current ordinary life stress. The results of this study suggest that PTSD symptoms decreased during the 7 years between assessments, and that current culture‐related stress is the most important variable related to the mental health of NK defectors living in South Korea.
CO2 laser revision stapedotomy
Authors: Albers Andreas E. , Schönfeld Uwe , Kandilakis Kostas , Jovanovic Sergije
Published: January 2013

Objectives/Hypothesis

To evaluate the safety and efficacy of the one‐shot noncontact technique in stapedotomy for revision stapes surgery with a CO2 laser combined with a scanning system.

Study Design

Prospective study.

Methods

Intraoperative findings and hearing results of 106 patients who underwent revision CO2 laser stapedotomy because of conductive or sensorineural hearing loss or vertigo were analyzed.

Results

Leading pathologies were displacement of the prosthesis, incus erosion, fibrous adhesions, and bony reobliteration or a too long or too short prosthesis. Surgery was successfully performed in all cases with a noncontact technique resulting in significantly improved postoperative air and bone conduction. The rate of permanent complications was 0.9%. A comparison of the effect of higher laser energies used for the perforation of bony stapes footplates and lower energies for neomembranes revealed no significant difference in hearing results, underscoring the safety of the technique.

Conclusions

To avoid any manipulation of the conductive hearing chain that may cause sensorineural hearing loss, we adapted the noncontact technique previously introduced by us for use in revision stapedotomy. This technique was successfully applied to improve conductive and sensorineural hearing loss as well as vertigo in first and second revision stapedotomy cases. Because the rate of postoperative complications was comparable to what is achieved with other laser systems, we conclude that the method has at least an equal level of safety. In conclusion, we advocate the use of a noncontact technique as suitable for an early revision of failed stapedotomy.

Level of Evidence

2b
Incidence of thyroid cancer surrounding three mile island nuclear facility: The 30‐year follow‐up
Authors: Levin Roger J. , De Simone Nicole F. , Slotkin Jaime F. , Henson Baker L.
Published: January 2013

Objectives/Hypothesis

Original data reported a potential increased incidence of thyroid cancer surrounding the Three Mile Island (TMI) nuclear facility. A causal link to the accident, however, was indeterminate. Our objective was to determine if data 30 years later will change original conclusions, explore thyroid cancer incidence rates near nuclear power plants, and better understand effects of chronic low level radiation.

Study Design

Retrospective cross‐sectional study.

Methods

Retrospective data for specific Pennsylvania counties were provided by the Pennsylvania Cancer Registry Dataset for thyroid cancer using the Epidemiological Query and Mapping System search engine. Our study examines thyroid cancer incidence from 1985 through 2009 analyzed by year, county, and age.

Results

Thirty years after the TMI accident, an increased incidence of thyroid cancer is seen in counties south of TMI and in high‐risk age groups. The average incidence rates from 1990 through 2009 were greater than expected in York, Lancaster, Adams, and Chester Counties.

Conclusions

Thyroid cancer incidence since the TMI accident was greater than expected in the counties analyzed when compared to local and national population growth. This supports a link to chronic low level radiation exposure and thyroid cancer development. Despite these findings, a direct correlation to the accident remains uncertain as incidence rates may coincide with other factors, and original data were limited.

Level of Evidence

2b Laryngoscope, 123:2064–2071, 2013
Subclassification of chronic rhinosinusitis
Authors: Han Joseph K.
Published: January 2013

Objectives/Hypothesis

There are variants of chronic rhinosinusitis (CRS). Therefore, the objectives of this study were to phenotype the subclasses of CRS as well as characterize their polyps with histology and cellular–intracellular biomarkers.

Study Design

Prospective case‐control study.

Methods

Demographic data, quality‐of‐life (QoL) questionnaires, nasal endoscopy (NE), and computed tomography (CT) scores were obtained. CRS was divided into seven subclasses: aspirin‐exacerbated respiratory disease (AERD), asthmatic sinusitis with and without allergy, nonasthmatic sinusitis with and without allergy, allergic fungal sinusitis (AFS), and cystic fibrosis (CF). Histopathologic and immunohistochemistry of nasal polyps were recorded. CD3, CD4, CD8, CD19, CD45, and CD56 data were collected. Interleukin (IL)4, IL5, IL13, IL17, and interferon (IFN)‐γ were measured.

Results

Eight‐four subjects were in this study. Two QoL questionnaires were inadequate at distinguishing the control group from CRS. NE and CT were able to differentiate between the control group and all CRS subclasses (P<.01). Asthmatic sinusitis, AERD, and AFS had high NE and CT scores, nasal polyps, eosinophils, mast cell, and hypercellularity. Asthmatic sinusitis, nonasthmatic sinusitis, and AERD had higher CD4 cells than control group (P<.05). Even though asthmatic sinusitis and AFS are mediated by Th2, AFS had differing levels of Th2 cytokines. Each nonasthmatic sinusitis had purulence and low CT score. Each nonasthmatic sinusitis had higher CD4 cells and IFN‐γ than control (P<.05). CF is associated with purulence, high CT score, high polymorphonuclear leukocytes, high plasma cells, and high mast cells.

Conclusions

Well‐characterized and distinct groups of CRS have been defined for targeted treatment and research studies.

Level of Evidence

2b Laryngoscope, 123:S15–S27, 2013
Retropharyngeal lymph node dissection in oropharyngeal cancer treated with transoral robotic surgery
Authors: Moore Eric J. , Ebrahimi Ardalan , Price Daniel L. , Olsen Kerry D.
Published: January 2013

Objectives/Hypothesis

Assess the role of retropharyngeal lymph node dissection in oropharyngeal squamous cell carcinoma treated with transoral robotic surgery (TORS).

Study Design

Prospective case series.

Methods

Retrospective analysis of 72 patients with oropharyngeal squamous carcinoma treated with transoral oropharyngectomy, neck dissection, and retropharyngeal node dissection.

Results

Eight of 55 (14.5%) patients with tonsil primaries had retropharyngeal metastases in contrast to none with tongue base primaries. The presence of pathologically positive retropharyngeal nodes was associated with clinical tumor (T) (P=.002) and node (N) stage (P=.007), preoperative computed tomography (CT) (P<.001), and positron emission tomography (PET)‐CT scan (P<.001). The negative predictive value of early T (Tx,1‐2) and N stage (N0‐N2a) was 91.7% and 100%, respectively. Preoperative CT and PET‐CT both yielded a positive predictive value of 100%, while the negative predictive value of imaging was optimized to 95.3% when these modalities were combined.

Conclusions

In patients with tonsil cancer the risk of retropharyngeal metastases is negligible in the presence of clinically T1‐2, N0‐N2a disease and negative CT and PET‐CT. We estimate that 40% of patients meet these criteria and may safely forego treatment of the retropharyngeal nodes. Approximately 10% of patients will have positive imaging and we recommend retropharyngeal node dissection at the time of surgery to treat macroscopic disease. In the remaining patients at risk for retropharyngeal node involvement, adjuvant radiotherapy is generally indicated based on other adverse features, and these nodes may be incorporated into the treatment field.

Level of Evidence

4. Laryngoscope, 2013