bluuebunny/crossref_metadata_2025 huggingface dataset:
Is NIH funding predictive of greater research productivity and impact among academic otolaryngologists?
Authors: Svider Peter F. , Mauro Kevin M. , Sanghvi Saurin , Setzen Michael , Baredes Soly , Eloy Jean Anderson
Published: September 2012

Objectives/Hypothesis:

The h‐index is an accurate and reliable indicator of scholarly productivity that takes into account relevance, significance, and influence of research contributions. As such, it is an effective, objective bibliometric that can be used to evaluate academic otolaryngologists for decisions regarding appointment and advancement. In this study, we evaluate the impact of NIH funding on scholarly productivity in otolaryngology.

Study Design:

Analysis of bibliometric data of academic otolaryngologists.

Methods:

Funding data for the 20 otolaryngology departments with the largest aggregate total of NIH grants for the fiscal years (FY) 2011 and 2012 was obtained using the National Institutes of Health Research Portfolio Online Reporting Tools Expenditures and Reports (RePORTER) Database. H‐indices were calculated using the Scopus online database, and then compared to funding data at both the departmental and individual level.

Results:

Faculty members in otolaryngology departments who received NIH funding had significantly greater research productivity and impact, as measured by the h‐index, than their nonfunded peers. H‐indices increased with greater NIH funding levels, and investigators with MD degrees tended to have higher mean NIH funding levels than those with PhDs. While there was no correlation between average h‐index and NIH funding totals at the level of departments, there was greater correlation upon examination of NIH funding levels of individual investigators.

Conclusions:

The h‐index has a strong relationship with, and may be predictive of, grant awards of NIH‐funded faculty members in otolaryngology departments. This bibliometric may be useful in decisions regarding appointment and advancement of faculty members within academic otolaryngology departments. Laryngoscope, 2013
What can Head‐Final Languages Tell us about Syntactic Priming (and vice versa)?
Authors: Arai Manabu
Published: September 2012

Syntactic priming, a phenomenon that previous exposure to a particular syntactic structure makes the structure more accessible in subsequent utterances, has widely been observed in both language production and comprehension. Previous research using this paradigm revealed a great deal about processing and representations of syntactic structures. Based on previous findings, it is recently proposed that priming plays a central role in the language processing and learning system. Such a claim often presumes that syntactic priming occurs in the same way across languages. Increasing evidence demonstrates priming in many different languages but what is challenging is to establish that syntactic priming is underlain by the same mechanism across languages. Perhaps the strongest test of such a common mechanism account is to examine the phenomenon in languages that are typologically different from English and other Germanic languages on which the majority of previous studies were conducted. To address this issue, this article reviews the previous studies conducted in head‐final languages. Finding that syntactic priming occurs in a similar way between head‐final languages and head‐initial languages would provide strong support to the common mechanism of priming across languages. Although evidence is still limited, previous studies support that syntactic priming occurs in head‐final languages in a similar way and possibly by the same mechanism as in head‐initial languages. I also discuss implications of the results of those studies for the syntactic representations and processing in head‐final languages.
VPS35 mutation in Japanese patients with typical Parkinson's disease
Authors: Ando Maya , Funayama Manabu , Li Yuanzhe , Kashihara Kenichi , Murakami Yoshitake , Ishizu Nobutaka , Toyoda Chizuko , Noguchi Katsuhiko , Hashimoto Takashi , Nakano Naoki , Sasaki Ryogen , Kokubo Yasumasa , Kuzuhara Shigeki , Ogaki Kotaro , Yamashita Chikara , Yoshino Hiroyo , Hatano Taku , Tomiyama Hiroyuki , Hattori Nobutaka
Published: September 2012

Vacuolar protein sorting 35 (VPS35) was recently reported to be a pathogenic gene for late‐onset autosomal dominant Parkinson's disease (PD), using exome sequencing. To date, VPS35 mutations have been detected only in whites with PD. The aim of the present study was to determine the incidence and clinical features of Asian PD patients with VPS35 mutations. We screened 7 reported nonsynonymous missense variants of VPS35, including p.D620N, known as potentially disease‐associated variants of PD, in 300 Japanese index patients with autosomal dominant PD and 433 patients with sporadic PD (SPD) by direct sequencing or high‐resolution melting (HRM) analysis. In addition, we screened 579 controls for the p.D620N mutation by HRM analysis. The p.D620N mutation was detected in 3 patients with autosomal dominant PD (1.0%), in 1 patient with SPD (0.23%), and in no controls. None of the other reported variants of VPS35 were detected. Haplotype analysis suggested at least 3 independent founders for Japanese patients with p.D620N mutation. Patients with the VPS35 mutation showed typical tremor‐predominant PD. We report Asian PD patients with the VPS35 mutation. Although VPS35 mutations are uncommon in PD, the frequency of such mutation is relatively higher in Japanese than reported in other populations. In VPS35, p.D620N substitution may be a mutational hot spot across different ethnic populations. Based on the clinical features, VPS35 should be analyzed in patients with PD, especially autosomal dominant PD or tremor‐predominant PD. © 2012 Movement Disorder Society
Effects of surface modification of carbon nanotube on platinum nanoparticle deposition using supercritical carbon dioxide fluid
Authors: Watanabe Mitsuhiro , Akimoto Tatsunori , Kondoh Eiichi
Published: September 2012

Platinum nanoparticles were fabricated on multiwalled carbon nanotubes (MWCNTs) by using supercritical fluid deposition. In this technique, deposition was carried out in a supercritical carbon dioxide fluid via hydrogen reduction of a dissolved platinum complex. The deposition temperature and deposition‐time dependences on the particle size and density were investigated. The obtained metallic nanoparticles/MWCNT nanocomposites were characterized by using transmission electron microscopy and scanning transmission electron microscopy. Crystalline pure platinum nanoparticles were clearly observed on the surfaces of MWCNTs. Most of the particles observed were smaller than 5 nm in diameter. The density of the particles increased with temperature between 393 and 423 K and decreased above 423 K. The nucleation of the nanoparticles took place within a deposition time of 60 min, and then agglomeration and coarsening occurred, resulting in an increase of the particle size. It was found that the surface topography of the carbon support greatly influences the platinum nucleation density. Indeed, when the MWCNTs were treated with hydrogen plasma prior to platinum deposition, the density of the nanoparticles markedly increased. The impact of the hydrogen plasma treatment on the particle‐size dependences was also investigated.
Bonding and optical contrast in phase change memory materials
Authors: Robertson J. , Huang B.
Published: September 2012

The large optical contrast between crystalline and amorphous phases of phase change memory materials is shown to arise from a large increase in the optical matrix elements which occurs when resonant bonding is present. Resonance requires aligned p orbitals, and is lost in the amorphous phases, irrespective of coordination number. Transitions in resonance can be engineered by superlattice structures.
High‐gain observers for leak location in subterranean pipelines of liquefied petroleum gas
Authors: Torres L. , Verde C. , Besançon G. , González O.
Published: September 2012

This paper describes a scheme based on high‐gain observers to detect and locate leaks in subterranean pipelines of liquefied petroleum gas (LPG). In fact, sub‐observers connected in cascade are used to generate residuals that allow to detect when a leak occurs and, above all, to isolate the region of the pipeline where the leak is located. Once the region is identified, a dedicated observer is employed to more precisely estimate the leak position as well as its coefficient. The approach is validated with data from a real industrial LPG pipeline. Copyright © 2012 John Wiley & Sons, Ltd.
Fault detection and isolation for networked control systems with finite frequency specifications
Authors: Long Yue , Yang Guang‐Hong
Published: September 2012

The fault detection and isolation (FDI) problem with finite frequency specifications is addressed in this paper under the framework of geometric approach for networked control systems subject to communication constraints and packet losses. The considered communication constraint is that only one of the transmission nodes is allowed to gain access to the shared channel. Also, those transmission nodes are scheduled to transmit data according to a specified stochastic protocol. Then by virtues of the common unobservable subspace and the finite frequency stochastic H −  index, a novel FDI scheme is developed in which a set of FDI filters that perform the FDI task with only partially available measurements are designed such that each residual is only sensitive to one fault in certain frequency domain and decoupled from the others. Further, less conservative conditions including some previous existing results have been presented to construct the FDI filters. Finally, an example is given to illustrate the effectiveness of the proposed method.Copyright © 2012 John Wiley & Sons, Ltd.
Direct imaging of the surface distribution of immobilized cleavable polyethylene oxide‐polybutadiene‐polyethylene oxide triblock surfactants by atomic force microscopy
Authors: Schilke Karl F. , Snider Joshua L. , Jansen Lauren E. , McGuire Joseph
Published: September 2012

Cleavable amphiphilic triblock surfactants with methoxypolyethylene oxide (PEO) side‐chains attached to polybutadiene (PBD) center blocks by ester linkages were synthesized. The PEO–PBD–PEO triblocks were adsorbed on hydrophobic silicon wafers and covalently stabilized by γ‐irradiation. The PEO side‐chains were then cleaved from the PBD backbones by acid hydrolysis. Decoration of the immobilized centerblocks with β‐cyclodextrin allowed direct imaging by standard atomic force microscopy techniques. Widely varied surface coverage, layer morphology and distributions of the PBD centerblocks were observed on surfaces coated with different triblock concentrations and PEO:PBD ratios. Surfaces coated from 1 mg/mL solutions of triblocks (near the critical aggregation concentration (CAC), 0.28–0.53 mg/mL) were sparsely coated, and triblocks containing 75–85% PEO exhibited negligible surface coverage, possibly due to poor adsorption or facile desorption during rinsing. Dense surface packings, albeit some with evident defects sufficiently large to allow for protein adsorption, were produced from 10 mg/mL triblock solutions (an order of magnitude above the CAC). This proof‐of‐concept report describes a method that may be useful in optimizing surface coatings on model substrates, and thus lend insight into optimization of coating conditions for economical production of non‐fouling triblock‐based PEO coatings on clinically relevant biomedical materials. Copyright © 2012 John Wiley & Sons, Ltd.
Boundaries and student self‐disclosure in authentic, integrated learning activities and assignments
Authors: Booth Melanie
Published: September 2012

How do we navigate the boundary challenges that arise when activities and assignments that are intended to foster and assess authentic and integrated student learning result in students disclosing private information?
Millennial values and boundaries in the classroom
Authors: Espinoza Chip
Published: September 2012

This chapter explores differences in generational values and behaviors. Understanding these differences will help faculty members set interpersonal boundaries that create an environment in which both student and teacher feel respected, appreciated, and capable.
Cisterna magna width at 11–13 weeks in the detection of posterior fossa anomalies
Authors: Garcia‐Posada R. , Eixarch E. , Sanz M. , Puerto B. , Figueras F. , Borrell A.
Published: September 2012

Objective

To construct reference ranges for cisterna magna (CM) width at 11–13 weeks' gestation in healthy fetuses and determine whether open spina bifida and posterior fossa anomalies could be diagnosed in the first trimester.

Methods

This was a retrospective study. CM width reference ranges were constructed based on the measurements obtained from 80 healthy fetuses with normal postnatal outcome undergoing routine first‐trimester ultrasound at 11–13 weeks, using the Lambda‐Mu‐Sigma method. CM was measured in the fetal mid‐sagittal view, as routinely used for nuchal translucency assessment. In addition, first‐trimester ultrasound images in 11 fetuses with open spina bifida or posterior fossa anomalies, most of which were diagnosed later in pregnancy, were retrospectively reviewed, and CM measurements were compared against reference ranges.

Results

CM width was noted to increase with gestational age in normal fetuses. The anomalies in the 11 fetuses we reviewed were: open spina bifida (n = 5), megacisterna magna (n = 3), Blake's pouch cyst (n = 2) and posterior fossa arachnoid cyst (n = 1). All fetuses with open spina bifida had a CM width below the 5th percentile. In the two fetuses with Blake's pouch cyst and in two with megacisterna magna, CM width was above the 95th percentile. In one of the fetuses with a megacisterna magna and the one with an arachnoid cyst, CM width was within normal range.

Conclusion

We have constructed reference ranges for CM width at 11–13 weeks using the mid‐sagittal view. It appears that first‐trimester CM width can be used as a marker for the early detection of open spina bifida. However, our findings need to be confirmed in prospective large series. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Classification and discrimination of some cosmetic face powders using XRF spectrometry with chemometric data analysis
Authors: Kulikov Elizabeth , Latham Kay , Adams Michael J.
Published: September 2012

Cosmetic foundation powders are one of the most commonly used cosmetic products in modern society. In recent years, the so‐called mineral‐based foundation products have become increasing popular in the cosmetic consumer market and can demand a premium price from the consumer. Manufacturers and suppliers often refer to mineral foundations as being ‘chemical free’, implying that these materials contain no potential skin irritants. However, there are no laws determining the use of the term ‘mineral cosmetic’ and interpretation of the use of the term is at the discretion of the manufacturer.

In this study, wavelength‐dispersive X‐ray fluorescence spectrometry has been employed for multi‐elemental analysis of 39 mineral and traditional ingredient cosmetic powders. Quantitative measurements were obtained for Al, Bi, Ca, Fe, K, Mg, Si, Ti and Zn. Using cluster analysis and principal components analysis, we could clearly identify the samples as being of traditional or mineral formulation, and in the case of the mineral samples, specific manufacturers could be distinguished. Of the samples examined, samples from two suppliers marketed as mineral‐based were determined as being indistinguishable from traditional formulations. Copyright © 2012 John Wiley & Sons, Ltd.
Clinical and biochemical features associated with BCS1L mutation
Authors: Al‐Owain Mohammed , Colak Dilek , Albakheet Albandary , Al‐Younes Banan , Al‐Humaidi Zainab , Al‐Sayed Moeen , Al‐Hindi Hindi , Al‐Sugair Abdulaziz , Al‐Muhaideb Ahmed , Rahbeeni Zuhair , Al‐Sehli Abdullah , Al‐Fadhli Fatima , Ozand Pinar T. , Taylor Robert W. , Kaya Namik
Published: September 2012

Our study describes a novel phenotype in a series of nine Saudi patients with lactic acidosis, from four consanguineous families three of which are related. Detailed genetic studies including linkage, homozygosity mapping and targeted sequencing identified a causative mutation in the BCS1L gene. All affected members of the families have an identical mutation in this gene, mutations of which are recognized causes of Björnstad syndrome, GRACILE syndrome and a syndrome of neonatal tubulopathy, encephalopathy, and liver failure (MIM 606104) leading to isolated mitochondrial respiratory chain complex III deficiency. Here we report the appearance of a novel behavioral (five patients) and psychiatric (two patients) phenotype associated with a p.Gly129Arg BCS1L mutation, differing from the phenotype in a previously reported singleton patient with this mutation. The psychiatric symptoms emanated after childhood, initially as hypomania later evolving into intermittent psychosis. Neuroradiological findings included subtle white matter abnormalities, whilst muscle histopathology and respiratory chain studies confirmed respiratory chain dysfunction. The variable neuro‐psychiatric manifestations and cortical visual dysfunction are most unusual and not reported associated with other BCS1L mutations. This report emphasizes the clinical heterogeneity associated with the mutation in BCS1L gene, even within the same family and we recommend that defects in this gene should be considered in the differential diagnosis of lactic acidosis with variable involvement of different organs.
Mass Spectrometry of the Lithium Adducts of Diacylglycerols Containing Hydroxy FA in Castor Oil and Two Normal FA
Authors: Lin Jiann‐Tsyh , Chen Grace Q. , Hou Ching T.
Published: September 2012

Castor oil can be used in industry. The molecular species of triacylglycerols containing hydroxy fatty acids (FA) in castor oil have been identified. We report here the identification of twelve diacylglycerols (DAG) containing hydroxy FA in castor oil using positive ion electrospray ionization mass spectrometry of the lithium adducts. They were RR (diricinolein, R is ricinoleate), RL, RS, R‐diOH18:0, R‐diOH18:1, R‐diOH18:2, R‐triOH18:0, R‐triOH18:1, R‐triOH18:2, diOH18:0‐diOH18:1, diOH18:1‐diOH18:1 and diOH18:1‐diOH18:2. The MS2 fragment ions, [M + Li − FA]+ and [FA + Li]+, from the lithium adducts of DAG containing hydroxy FA (one or two hydroxy FA), were used for the identification. The additional fragment ions from the neutral losses of FA lithium salts [M + Li − FALi]+ were used for the identification of eleven DAG containing two normal FA in a soybean oil bioconversion product. The MS2 fragment ions from the neutral losses of FA lithium salts [M + Li − FALi]+ were not detected from the DAG containing hydroxy FA. The DAG containing FA with more hydroxyl groups than the other FA on the same DAG molecule tended to have a prominent fragment ion [FA + Li]+ and an undetectable fragment ion [M + Li − FA]+ while the FA was the more hydroxylated FA. Also the less hydroxylated FA of a DAG tended to have a prominent fragment ion [M + Li − FA]+ and an undetectable fragment ion [FA + Li]+ while the FA was the less hydroxylated FA.
Quadricepsplasty for congenital dislocation of the knee and congenital quadriceps contracture
Authors: Tercier Stéphane , Shah Hitesh , Joseph Benjamin
Published: September 2012

Purpose

We encountered problems with the Curtis and Fisher technique of quadricepsplasty for congenital quadriceps contracture, including wound dehiscence, insufficient lengthening of the quadriceps and instability of the knee. We modified the operative technique to address these three problems. We undertook this study to evaluate the results of the modified technique of quadricepsplasty to determine if we succeeded in overcoming these limitations of the original technique.

Methods

Twenty children (33 knees) underwent the modified Curtis and Fisher quadricepsplasty through a lateral incision; a long tongue of the rectus femoris was raised and the vasti mobilised without dividing the lateral retinaculae till the collateral ligaments. The children were followed up for a mean period of 63 months and evaluated. The healing of the wound, active and passive range of motion (ROM) of the knee, the stability of the knee, quadriceps power and knee function were assessed.

Results

Primary wound healing occurred in 32 of 33 knees. Adequate lengthening of the quadriceps sufficient to facilitate knee flexion to 90° was possible. Considerable improvement in the ROM was noted. In non-syndromic congenital dislocation of the knee (CDK), the quadriceps power was Grade 5, but minor degrees of extensor lag was noted. In a proportion of patients, minor degrees of joint instability was present. The majority of children were community walkers. The overall results were better in non-syndromic CDK than in children with arthrogryposis, but differences of some variables were not significant.

Conclusion

The modifications to the original Curtis and Fisher technique overcame the specific problems they were expected to avoid.
Time for Children: Trends in the Employment Patterns of Parents, 1967–2009
Authors: Fox Liana , Han Wen-Jui , Ruhm Christopher , Waldfogel Jane
Published: September 2012

Using data from the 1967–2009 years of the March Current Population Surveys (CPS), we examine two important resources for children’s well-being: time and money. We document trends in parental employment, from the perspective of children, and show what underlies these trends. We find that increases in family work hours mainly reflect movements into jobs by parents—particularly mothers, who in prior decades would have remained at home. This increase in market work has raised incomes for children in the typical two-parent family but not for those in lone-parent households. Time use data from 1975 and 2003–2008 reveal that working parents spend less time engaged in primary childcare than their counterparts without jobs but more than employed peers in previous cohorts. Analysis of 2004 work schedule data suggests that non-daytime work provides an alternative method of coordinating employment schedules for some dual-earner families.
Nation-Work: A Praxeology of Making and Maintaining Nations
Authors: Surak Kristin
Published: September 2012

This article bridges the literatures on nationalist projects and everyday nationhood by elucidating a repertoire of actions shared by both. Analysis of such “nation-work” contributes to the cognitive turn in ethnicity and nationalism research by showing how ethnonational categorization operates. Examining variation in this domain shows that though nationalism may project an image of a homogeneous “we”, internal heterogeneity is crucial for refining the experience and performance of membership in the nation.
Toll‐like receptor 3 activation differentially regulates phagocytosis of bacteria and apoptotic neutrophils by mouse peritoneal macrophages
Authors: Deng Tingting , Feng Xueying , Liu Peipei , Yan Keqin , Chen Yongmei , Han Daishu
Published: September 2012

Toll‐like receptor (TLR) activation by microbial pathogens triggers inflammatory responses against microbes. The phagocytic clearance of invading microbes and apoptotic immune cells is essential to resolve inflammation. However, the relationship between TLR activation and phagocytosis is poorly understood. We found that TLR3 activation promotes bacterial uptake through the activation of interferon‐regulating factor 3 (IRF3) and inhibits phagocytosis of apoptotic neutrophils through the activation of nuclear factor‐κB (NF‐κB) by mouse peritoneal macrophages. The TLR signals that regulate the phagocytic ability of macrophages were also induced by TLR4 and TLR5 activation. Further, we demonstrated that TLR‐induced tumor necrosis factor‐α and interferon‐β contributed to the differential phagocytosis of apoptotic neutrophils and bacteria by macrophages. Moreover, activation of IRF3 upregulated the expression of some receptors involved in bacterial uptake, whereas activation of NF‐κB downregulated the expression of molecules that facilitate the phagocytosis of apoptotic cells. These results describe an effect of TLR‐triggered innate immunity on the phagocytic activity of macrophages.
Spectral effects of UV on psoriasis
Authors: Weatherhead Sophie C. , Farr Peter M. , Reynolds Nicholas J.
Published: September 2012

Ultraviolet B (UVB) is a highly effective, relatively safe, affordable and widely used therapeutic option for moderate psoriasis. Several types of UVB lamp are available to treat psoriasis, both broadband and narrowband, allowing a choice of spectral emission. However despite years of clinical use, the mechanism of action of UVB in clearing psoriasis remained incompletely understood. Moreover, there has been little insight into how the relative effectiveness of different UVB wavelengths linked to the mechanism of action, although it is known that the action spectrum for clearance of psoriasis differs from the action spectrum of erythema. This paper examines the existing literature from which our current treatments have evolved, and offers new insight into the use of keratinocyte apoptosis as a biomarker which may help to optimise UV treatment in the future. When combined with a systems biology approach, this potential biomarker may provide insight into which wavelengths of UV are the most effective in clearing psoriasis, allowing a more rational and potentially an individually tailored approach to optimising phototherapy for psoriasis.
Dynamic changes in genomic histone association and modification during activation of the ASNS and ATF3 genes by amino acid limitation
Authors: Balasubramanian Mukundh N. , Shan Jixiu , Kilberg Michael S.
Published: September 2012

Amino acid deprivation of mammalian cells triggers several signalling pathways, the AAR (amino acid response), that results in transcriptional activation. For the ASNS (asparagine synthetase) and ATF3 (activating transcription factor 3) genes, increased transcription occurs in conjunction with recruitment of ATF4 to the gene. In HepG2 cells, analysis of the ASNS and ATF3 genes during AAR activation revealed increases in histone H3K4me3 (histone 3 trimethylated Lys4) and H4Ac (acetylated histone 4) levels, marks associated with active transcription, but a concurrent loss of total H3 protein near the promoter. The dynamic nature of AAR-regulated transcription was illustrated by a decline in ASNS transcription activity within minutes after removal of the AAR stress and a return to basal levels by 2 h. Reversal of ASNS transcription occurred in parallel with decreased promoter-associated H4Ac and ATF4 binding. However, the reduction in histone H3 and increase in H3K4me3 were not reversed. In yeast, persistence of H3K4me3 has been proposed to be a ‘memory’ mark of gene activity that alters the responsiveness of the gene, but the time course and magnitude of ASNS induction was unaffected when cells were challenged with a second round of AAR activation. The results of the present study document changes in gene-associated nucleosome abundance and histone modifications in response to amino-acid-dependent transcription.
Intense green and red upconversion emission of Er3+,Yb3+ co-doped CaZrO3 obtained by a solution combustion reaction
Authors: Singh Vijay , Kumar Rai Vineet , Haase Markus
Published: September 2012

CaZrO3 phosphors co-doped with Er3+ and Yb3+ ions have been prepared by the urea combustion route. The formation of the orthorhombic phase of CaZrO3 was confirmed by powder x-ray diffraction. The absorption in the 280–1800 nm region and excitation spectrum corresponding to the emission at 545 nm for CaZrO3:Er3+/CaZrO3:Er3+,Yb3+ phosphors have been recorded. Upon excitation at 978 nm, the material displays strong energy transfer upconversion emission in the green and red spectral regions. The upconversion emission of the CaZrO3:Er3+,Yb3+ co-doped material shows an increased red-to-green ratio, indicating cross relaxation between Er3+ ions.
Measurement of resonant mode of piezoelectric thin plate using speckle interferometry and frequency-sweeping function
Authors: Chang Ching-Yuan , Ma Chien-Ching
Published: September 2012

This study proposes a frequency-sweeping function of electronic speckle pattern interferometry, based on standard deviation in the temporal domain. The proposed method facilities the measurement of resonant vibration, and provides stable and clear interference fringes. This study investigated the third in-plane eigenmode of a thin piezoelectric plate, using the finite element method and an impedance analyzer to verify the dynamic response obtained using the proposed method. We analyzed the vibration amplitude of interference fringes to obtain quantitative results on the sub-micron scale. The close agreement between the experimental results demonstrates the effectiveness of using the frequency-sweeping function to obtain the resonant states and provides an accurate prediction of resonance. Furthermore, statistical analysis of interference fringes obtained using the subtractive, mean, and the standard deviation method is performed. The result shows that the standard deviation method provides higher quality and stability of fringe pattern.
Effect of MgO spacer and annealing on interface and magnetic properties of ion beam sputtered NiFe/Mg/MgO/CoFe layer structures
Authors: Bhusan Singh Braj , Chaudhary Sujeet
Published: September 2012

The effect of variation in the thickness of ion assisted ion beam sputtered MgO spacer layer deposited at oxygen ion assisted energy of 50 eV on the extent of magnetic coupling of NiFe and CoFe layers in Si/NiFe(10 nm)/Mg(1 nm)/MgO(2,4,6 nm)/CoFe(10 nm) sandwich structure is investigated. At MgO spacer layer thickness of 4 nm, the separate reversal of magnetizations of the two ferromagnetic layers is observed in the hystresis loop recorded along easy direction. This results in a 3.5 Oe wide plateau like region during magnetization reversal, which became 4.5 Oe at 6 nm thin MgO. At 2 nm thin MgO, the absence of plateau during magnetization reversal region revealed ferromagnetic coupling between the two ferromagnetic layers, which is understood to arise due to the growth of very thin and low density (1.22 gm/cc) MgO spacer layer, indicating the presence of pinholes as revealed by x-ray reflectometry. After vaccum annealing (200 °C/1 h), the plateau region for 4 and 6 nm thin MgO case decreased to 1.5 Oe and 2.0 Oe, respectively, due to enhanced interface roughness/mixing. In addition, an enhancement of the in-plane magnetic anisotropy is also observed.
Effect of grain boundary on the electromechanical response of ferroelectric polycrystals
Authors: Shu Weilin , Wang Jie , Zhang Tong-Yi
Published: September 2012

The effect of grain boundaries on the electromechanical response of a ferroelectric polycrystal subjected to an electric field or stress is investigated numerically by using a phase field model. The grain boundaries in the phase field model are regarded as dielectrics in which the ferroelectric properties are degraded completely. The phase field simulations show that the presence of dielectric grain boundaries results in a large build-in depolarizing field in grains. The depolarizing field has a significant influence on the coercive field, the switching behaviour of ferroelectric domain under an electric field or stress, and the piezoelectric and dielectric properties of the ferroelectric polycrystal. It is found that both coercive field and remnant polarization decrease with the increase of the thickness of dielectric grain boundary. However, the piezoelectric coefficient and permittivity of the ferroelectric polycrystal become larger when the thickness of dielectric grain boundary increases. The enhancement of dielectric and piezoelectric properties by the dielectric grain boundary suggests a new degree of freedom to tune the electromechanical response of ferroelectric polycrystalline materials.
Comparison of the performance of exact-exchange-based density functional methods
Authors: Liu Fenglai , Proynov Emil , Yu Jian-Guo , Furlani Thomas R. , Kong Jing
Published: September 2012

How to describe nondynamic electron correlation is still a major challenge to density functional theory (DFT). Recent models designed particularly for this problem, such as Becke'05 (B05) and Perdew-Staroverov-Tao-Scuseria (PSTS) functionals employ the exact-exchange density, the efficient calculation of which is technically quite challenging. We have recently implemented self-consistently the B05 functional based on an efficient resolution-identity (RI) technique. In this study, we report a self-consistent RI implementation of the PSTS functional. In contrast to its original implementation, our version brings no limitation on the choice of the basis set. We have also implemented the Mori-Sanchez-Cohen-Yang-2 (MCY2) functional, another recent DFT method that includes full exact exchange. The performance of PSTS, B05, and MCY2 is validated on thermochemistry, reaction barriers, and dissociation energy curves, with an emphasis on nondynamic correlation effects in the discussion. All three methods perform rather well in general, B05 and MCY2 being on average somewhat better than PSTS. We include also results with other functionals that represent various aspects of the development in this field in recent years, including B3LYP, M06-HF, M06-2X, ωB97X, and TPSSh. The performance of the heavy-parameterized functionals M06-2X and ωB97X is on average better than that of B05, MCY2, and PSTS for standard thermodynamic properties and reactions, while the latter functionals do better in hydrogen abstraction reactions and dissociation processes. In particular, B05 is found to be the only functional that yields qualitatively correct dissociation curves for two-center symmetric radicals like \documentclass[12pt]{minimal}\begin{document}${\rm He}_{2}^{+}$\end{document} He 2+. Finally, we compare the performance of all these functionals on a strongly correlated exemplary case system, the NO dimer. Only PSTS, B05, and MCY2 describe the system qualitatively correctly. Overall, this new type of functionals show good promise of overcoming some of the difficulties DFT encounters for systems with strong nondynamic correlation.
Large size metallic glass gratings by embossing
Authors: Ma J. , Yi J. , Zhao D. Q. , Pan M. X. , Wang W. H.
Published: September 2012

Bulk metallic glasses have excellent thermoforming ability in their wide supercooled liquid region. We show that large-size metallic glass grating (∼8 × 8 mm2) with fine periodicity and ultra smooth surface feature can be readily fabricated by hot embossing. The method for fabrication of gratings is proved to be much cheaper, and requires low pressure and short time (less than 30 s). The metallic glass gratings exhibit comparable optical properties such as rainbow-like spectrum when shone by fluorescent lamp light.
Influence of a strong laser field on Coulomb explosion and stopping power of energetic H3+ clusters in plasmas
Authors: Wang Gui-Qiu , E Peng , Wang You-Nian , Hu Zhang-Hu , Gao Hong , Wang Yao-Chuan , Yao Li , Zhong Hai-Yang , Cheng Li-Hong , Yang Kun , Liu Wei , Xu Dian-Guo
Published: September 2012

The influence of a high-intensity laser field on the Coulomb explosion and stopping power for a swift H3+ cluster ion in a plasma target is studied by means of the molecular dynamic (MD) method based on the linearized Vlasov–Poisson theory. Excitations of the plasma are described by the classical plasma dielectric function. In the presence of the laser field, the general expressions for the induced potential in the target and the interaction force among the ions within the cluster are derived. Based on the numerical solution of the equations of motion for the constituent ions, the Coulomb explosion patterns and the cluster's stopping power are discussed for a range of laser parameters. Numerical results show that the laser field affects the correlation between the ions and contributes to weaken the wake effect and the stopping power as compared to the laser-free case. On the other hand, the stopping power ratio of H3+ cluster is higher than the situation of dicluster of H2+ due to the vicinage effect in the cluster.
Optical absorption spectra of gold clusters Aun (n = 4, 6, 8,12, 20) from long-range corrected functionals with optimal tuning
Authors: Koppen Jessica V. , Hapka Michał , Szczęśniak Małgorzata M. , Chałasiński Grzegorz
Published: September 2012

Absorption UV spectra of gold clusters Aun (n = 4, 6, 8, 12, 20) are investigated using the time-dependent density functional theory (TDDFT). The calculations employ several long-range corrected xc functionals: ωB97X, LC-ωPBEh, CAM-B3LYP* (where * denotes a variant with corrected asymptote of CAM-B3LYP), and LC-ωPBE. The latter two are subject to first-principle tuning according to a prescription of Stein et al. [Phys. Rev. Lett. 105, 266802 (2010)10.1103/PhysRevLett.105.266802] by varying the range separation parameter. TDDFT results are validated for Au4 and Au8 against the equation-of-motion coupled cluster singles and doubles results and the experiment. Both long-range correction and the inclusion of a fixed portion of the exact exchange in the short-range are essential for the proper description of the optical spectra of gold. The ωB97X functional performs well across all studied cluster sizes. LC-ωPBEh, with parameters recommended by Rohrdanz et al. [J. Chem. Phys. 130, 054112 (2009)10.1063/1.3073302], affords the best performance for clusters of n > 4. The optimally tuned CAM-B3LYP* features the range separation parameter of 0.33 for Au4 and 0.25 for all the larger clusters. For LC-ωPBE the tuning procedure resulted in incorrect transition energies and oscillator strengths despite the fact that the optimized functional showed the accurate linear dependence on fractional electron numbers. Aun (n = 4, 6, 8) feature optical gaps above of 3 eV and Au20 of ∼2.9 eV. In Au12 this gap narrows to ∼2.1 eV. The calculated spectrum for Au20 involves intensity being concentrated in only a few transitions with the absorption maximum at 3.5 eV. The intense 3.5 eV absorption is present in all cluster sizes of n > 4. The calculated HOMO-LUMO gaps for all cluster sizes are within 0.5 eV of the difference between the vertical ionization potential and electron affinity. The reasons for this and for the failure of conventional xc functionals for optical spectra of gold are discussed.
Experimental and theoretical studies of the decomposition of new imidazole based energetic materials: Model systems
Authors: Yu Zijun , Bernstein Elliot R.
Published: September 2012

Decomposition of three imidazole based model energetic systems (2-nitroimidazole, 4-nitroimidazole, and 1-methyl-5-nitroimidazole) is investigated both experimentally and theoretically. The initial decomposition mechanism for these three nitroimidazoles is explored with nanosecond energy resolved spectroscopy, and quantum chemical theory at the complete active space self-consistent field (CASSCF) level. The NO molecule is observed as an initial decomposition product from these three nitroimidazoles subsequent to UV excitation. A unique, excitation wavelength independent dissociation channel is observed for these three nitroimidazoles that generates the NO product with a rotationally cold (∼50 K) and a vibrationally mildly hot (∼800 K) distribution. Potential energy surface calculations at the CASSCF/6-31G(d) level of theory illustrate that conical intersections play an important and essential role in the decomposition mechanism. Electronically excited S2 nitroimidazole molecules relax to the S1 state through the (S2/S1)CI conical intersection, and undergo a nitro-nitrite isomerization to generate the NO product from the S1 potential energy surface. Nevertheless, NO2 elimination and nitro-nitrite isomerization are expected to be competitive reaction mechanisms for the decomposition of these molecules on the ground state potential energy surface from the Franck-Condon equilibrium geometry through thermal dissociation.
Magnetic properties of MoS2: Existence of ferromagnetism
Authors: Tongay Sefaattin , Varnoosfaderani Sima S. , Appleton Bill R. , Wu Junqiao , Hebard Arthur F.
Published: September 2012

We report on the magnetic properties of MoS2 measured from room temperature down to 10 K and magnetic fields up to 5 T. We find that single crystals of MoS2 display ferromagnetism superimposed onto large temperature-dependent diamagnetism and have observed that ferromagnetism persists from 10 K up to room temperature. We attribute the existence of ferromagnetism partly to the presence of zigzag edges in the magnetic ground state at the grain boundaries. Since the magnetic measurements are relatively insensitive to the interlayer coupling, these results are expected to be valid in the single layer limit.
Influence of surface plasmon propagation on leakage radiation microscopy imaging
Authors: Guebrou S. Aberra , Laverdant J. , Symonds C. , Vignoli S. , Bessueille F. , Bellessa J.
Published: September 2012

We study in this Letter, the effect of the surface plasmon (SP) propagation and coherence on the images obtained by leakage radiation microscopy. The studied system is a set of nanocrystals deposited on a thin silver film supporting surface plasmon modes. More than 70% of the emission in this typical system comes from non-local emission. The diameter of the influence circle around the detection point is of the order of magnitude of the plasmon propagation length. We also present an original method to measure the propagation length (Lspp) of surface plasmons in complex systems by a two Young's slits experiment. This method can be useful for complex systems with a very short propagation length.
Ordered ZnO nanorods-based heterojunction light-emitting diodes with graphene current spreading layer
Authors: Zhang S. G. , Zhang X. W. , Si F. T. , Dong J. J. , Wang J. X. , Liu X. , Yin Z. G. , Gao H. L.
Published: September 2012

Ordered ZnO nanorods-based heterojunction light-emitting diodes (LEDs) have been fabricated by adopting few-layer graphene as a current spreading layer. The strong emission at low currents infers the high interfacial quality between GaN and ordered ZnO nanorods, and the current spreading effect resulting from graphene. The improved electroluminescence performance was achieved compared to the ZnO nanorods-based LED with a conventional indium-tin-oxide electrode, which can be attributed to the stable, reliable, and low resistance ohmic-contacts between graphene and ZnO nanorods, as well as the high transmittance of graphene. These results demonstrate feasibility of using graphene as electrodes for high-efficiency ZnO nanorods-based LEDs.
Energy transfer in finite-size exciton-phonon systems: Confinement-enhanced quantum decoherence
Authors: Pouthier Vincent
Published: September 2012

Based on the operatorial formulation of the perturbation theory, the exciton-phonon problem is revisited for investigating exciton-mediated energy flow in a finite-size lattice. Within this method, the exciton-phonon entanglement is taken into account through a dual dressing mechanism so that exciton and phonons are treated on an equal footing. In a marked contrast with what happens in an infinite lattice, it is shown that the dynamics of the exciton density is governed by several time scales. The density evolves coherently in the short-time limit, whereas a relaxation mechanism occurs over intermediated time scales. Consequently, in the long-time limit, the density converges toward a nearly uniform distributed equilibrium distribution. Such a behavior results from quantum decoherence that originates in the fact that the phonons evolve differently depending on the path followed by the exciton to tunnel along the lattice. Although the relaxation rate increases with the temperature and with the coupling, it decreases with the lattice size, suggesting that the decoherence is inherent to the confinement.
Recovery improvement of graphene-based gas sensors functionalized with nanoscale heterojunctions
Authors: Kang Il-Suk , So Hye-Mi , Bang Gyeong-Sook , Kwak Jun-Hyuk , Lee Jeong-O , Won Ahn Chi
Published: September 2012

We report a development of reduced graphene oxide (rGO)-based gas sensors with a practical recovery by facile functionalization with tin dioxide nanoclusters. Upon the introduction of UV illumination to this nanostructure, the reaction on surfaces of tin dioxide nanoclusters was activated and thereby the nanoscale heterojunction barriers between the rGO sheet and the nanoclusters were developed. This lowered the conductance to quickly recover, which was intensified as the cluster density has reached to the percolation threshold. However, after the formation of the cluster percolating network, the sensor response has totally changed into a deterioration of the sensitivity as well as the recovery.
Study of the precursor and non-precursor implosion regimes in wire array Z-pinches
Authors: Papp D. , Ivanov V. V. , Jones B. , Haboub A. , Anderson A. A. , Altemara S. D. , Talbot B. R.
Published: September 2012

Star-like and closely spaced nested wire array configurations were investigated in precursor and non-precursor implosions. Closely spaced nested cylindrical arrays have inner and outer arrays with equal wire numbers, and inner and outer wires aligned to each other. The gap between the outer and inner wires is not more than 1 mm. Calculation of magnetic fields shows that the small gap results in a reversed, outward j × B force on the inner wires. Closely spaced arrays of 6–16 wires with outer diameter of 16 mm and with gaps of ΔR = 0.25–1 mm were tested. 6–8-wire arrays with a gap of ΔR = 0.4–1 mm imploded without precursor, but precursor was present in loads with 12–16 wires and ΔR = 0.25–1 mm. Implosion dynamics of closely spaced arrays was similar to that of star-like arrays. Implosion time was found to decrease with decreased wire numbers. Star array configurations were designed with a numerical scheme to implode with or without precursor. The lack of precursor resulted in a marginal improvement in total x-ray yield and power, and up to 20% increase in Al K-shell yield. The Al K-shell radiated energy was found to increase with decreasing the number of arrays in closely spaced and star-like wire arrays.
Effect of dietary supplementation with Acacia karroo leaves on fatty acid profiles and consumer sensory attributes of Xhosa lop-eared goats under artificial haemonchosis
Authors: Marume U. , Hugo A. , Chimonyo M. , Muchenje V. , Dzama K.
Published: September 2012

The effect of Acacia karroo supplementation on fatty acid profiles and sensory attributes of Xhosa lop-eared goats meat was evaluated in 18 4-month-old goats exposed to a single dose of 6000 L3 Haemonchus contortus larvae. The goats were allotted into two groups: non-supplemented (NSP) and supplemented (AK). The AK goats received 200 g of fresh A. karroo leaves. At the end of the experiment, all the goats were slaughtered to determine the fatty acid profiles and sensory perceptions. Faecal larval counts decreased significantly in the AK group as the infection progressed, while it increased in the NSP group. At necropsy, the NSP group had significantly higher worm counts than the AK group. The AK group contained significantly higher (P < 0.05) amounts of intramuscular fat and had almost twice (P < 0.05) the total polyunsaturated fatty acids and polyunsaturated fatty acid/monounsaturated fatty acid ratio. Furthermore, the AK goats also had higher amounts (P < 0.05) of n-3. Mean sensory scores for juiciness and tenderness were superior in the AK goats (P < 0.05). In conclusion, A. karroo supplementation positively influenced the fatty acid composition and sensory attributes of chevon from goats infected with H. contortus.