bluuebunny/crossref_metadata_2025 huggingface dataset:
Botulinum Toxin Use as an Adjunctive Modality in a Patient with Multiple Flexor Tendon Ruptures
Authors: Kubat Wade D. , Rekant Mark
Published: March 2008

Botulinum toxin A has been described in treatment protocols for several disease processes, from primary axillary hyperhydorosis to esophageal dysfunction. It is best known for its use in plastic and dermatological practices. Botulinum toxin has a straightforward mechanism of action. The toxin inhibits acetylcholine release at the neuromuscular junction causing a chemical denervation, which ceases contractions of the muscle. With its minimal side effect profile, botulinum toxin should be considered when muscle spasm is a detriment. This case involves an injury to the hand of a patient with a history of intermittent diffuse muscle spasms. Subsequently, due to the patient's previous upper extremity muscle spasms, repeated flexor tendon repair ruptures of the index finger occurred until botulinum toxin was administered to the offending muscle. The patient has not required any additional surgical interventions for the repaired tendon and is now actively flexing all digits. This case report demonstrates how botulinum toxin can be used in a clinical scenario when decreased muscle activity is desired to promote tendon healing.
Plasma connective tissue growth factor is a novel potential biomarker of cardiac dysfunction in patients with chronic heart failure
Authors: Koitabashi Norimichi , Arai Masashi , Niwano Kazuo , Watanabe Atai , Endoh Michiko , Suguta Masahiko , Yokoyama Tomoyuki , Tada Hiroshi , Toyama Takuji , Adachi Hitoshi , Naito Shigeto , Oshima Shigeru , Nishida Takashi , Kubota Satoshi , Takigawa Masaharu , Kurabayashi Masahiko
Published: March 2008

Background:

Connective tissue growth factor (CTGF) has been recently reported as a mediator of myocardial fibrosis; however, the significance of plasma CTGF concentration has not been evaluated in patients with heart failure. The aim of this study was to investigate the clinical utility of plasma CTGF concentration for the diagnosis of heart failure.

Methods and results:

We evaluated fifty‐two patients with chronic heart failure. The plasma concentration of CTGF and other markers of fibrosis were assessed and compared with clinical and echocardiographic data. Plasma CTGF was significantly elevated in symptomatic patients in proportion to their NYHA classes and was significantly correlated with plasma brain natriuretic peptide (BNP) concentration (r = 0.395, P < 0.01). Plasma CTGF was also correlated with plasma transforming growth factor beta (TGF‐β) (r = 0.512, P < 0.01), matrix metalloproteinase (MMP)‐2 (r = 0.391, P < 0.05) and tissue inhibitor of MMP (TIMP)‐2 (r = 0.354, P < 0.05) concentrations. Interestingly, plasma CTGF was correlated with E/E' value evaluated by tissue Doppler echocardiography (r = 0.593, P = 0.012), but not with systolic function and left ventricular mass.

Conclusion:

Our study suggests that plasma CTGF concentration is a novel diagnostic marker for cardiac dysfunction and may provide additional specific information about myocardial fibrosis in chronic heart failure patients.
Childhood Family Structure and Personality Disorders in Adulthood
Authors: Kantojärvi L. , Joukamaa M. , Miettunen J. , Läksy K. , Herva A. , Karvonen J.T. , Taanila A. , Veijola J.
Published: March 2008

Background.

The association between childhood family structure and sociodemographic characteristics and personality disorders (PDs) in a general population sample was studied.

Methods.

This study is a substudy of the prospective Northern Finland 1966 Birth Cohort Project with 1588 young adult subjects. The case-finding methods according to the DSM-III-R criteria for PDs were: (1) Structured Clinical Interview for DSM-III-R (SCID) for 321 cases who participated in a 2-phase field study, (2) Finnish Hospital Discharge Register data, and (3) analysis of the patient records in public outpatient care in 1982–1997. Statistical analyses were performed on the association between PDs and family background factors.

Results.

Altogether 110 (7.0%) of the subjects had at least one probable or definite PD. After adjusting for confounders (gender, parental social class and parental psychiatric disorder) the results indicated that single-parent family type in childhood was associated with cluster B PDs in adulthood. Being an only child in childhood was associated with cluster A PDs. No special childhood risk factors were found for cluster C PDs.

Conclusions.

Results suggest that single-parent family type at birth and being an only child in the 1960s are associated with PD in adulthood. Further studies are needed to explore the psychosocial aspects of family environment which may nowadays promote vulnerability to PDs in adulthood.
Cortisol Response To Interpersonal Stress in Young Adults With Borderline Personality Disorder: A Pilot Study
Authors: Walter Marc , Bureau Jean-François , Holmes Bjarne M. , Bertha Eszter A. , Hollander Michael , Wheelis Joan , Brooks Nancy Hall , Lyons-Ruth Karlen
Published: March 2008

Hypothalamic–pituitary–adrenal axis dysregulation after stress was found to be associated with borderline personality disorder (BPD). Nine female BPD young adults and 12 control subjects were investigated for stress reactivity and recovery after an interpersonal conflict discussion with their mothers. BPD subjects showed a delayed cortisol response after psychosocial stress.
Justice from Above or Below? Popular Strategies for Resolving Grievances in Rural China
Authors: Michelson Ethan
Published: March 2008

Research on rural conflict in China suggests that village leaders are sources of trouble and obstacles to justice and that aggrieved villagers have more trust in and receive more satisfactory redress from higher-level solutions than from local solutions. In contrast to this account of “justice from above,” evidence presented in this article from a 2002 survey of almost 3,000 households supports an alternative theory of “justice from below.” According to this latter theory, the social costs associated with appealing to higher authorities, including the legal system, for help with local disputes tend both to discourage the escalation of disputes and to produce relatively disappointing experiences and outcomes when such routes are taken. Survey respondents indicated that local solutions, often with the involvement of village leaders, were far more desirable and effective than higher-level solutions.
China's Emerging Credit Rating Industry: The Official Foundations of Private Authority
Authors: Kennedy Scott
Published: March 2008

Although China has had difficulty improving the performance of its banks and stock markets, it has struggled even more to develop a credit rating industry. Credit rating agencies (CRA), which provide bond ratings, are vital to financial markets in advanced capitalist countries, but China's credit rating companies are weak and have had little influence over the behaviour of those who issue or invest in bonds. Some argue that CRAs gain authority through their strong reputation in the eyes of market participants, but the experience of rating agencies in China supports evidence from elsewhere that their private authority is largely dependent on government mandate, a benefit China's CRAs have only recently begun to enjoy. Many private actors, from trade associations to charity groups, are struggling to gain public influence in China, but credit rating agencies may be the best barometer to measure the Chinese government's general stance towards private authority.
Making Sense of Participation: The Political Culture of Pro-democracy Demonstrators in Hong Kong
Authors: Lee Francis L. F. , Chan Joseph M.
Published: March 2008

A wave of large-scale demonstrations from 2003 to 2006 has given rise to a new pro-democracy movement in Hong Kong and raised important questions about the political activism of the Hong Kong public. This study aims at achieving a better understanding of the cultural underpinnings of Hong Kong people's protest participation (and non-participation). Following a tradition of constructivist analysis which sees culture as a set of shared and more or less structured ideas, symbols, feelings and common senses, this study examines how participants in the pro-democracy protests make sense of their experiences and the ongoing political and social changes in Hong Kong. It shows that the 1 July 2003 demonstration has indeed empowered many of its participants, but feelings of efficacy became more complicated and mixed as people continued to monitor changes in the political environment and interpret the actions of others. At the same time, beliefs and ideas that can be regarded as part of Hong Kong's culture of de-politicization remain prevalent among the protesters. The findings of the study allow us to understand why many Hong Kong people view protests as important means of public opinion expression and yet participate in them only occasionally.
The 1967 Riots in Hong Kong: The Diplomatic and Domestic Fronts of the Colonial Governor
Authors: Yep Ray
Published: March 2008

This article examines the dynamics behind the Hong Kong colonial government's policy during the 1967 riots, a turning point in the colony's development. Starting as an industrial dispute, it soon erupted into a major crisis that prompted the British to consider evacuation from the territory. While the Governor, David Trench, was preoccupied with the colossal task of maintaining order on the domestic front, his success was heavily dependent on his progress on the “diplomatic front.” His perception of British interests did not always resonate with the views of the British diplomats in China. This article argues that the prevalence of Trench's proposed policy of firm suppression of local communists over the accommodating approach, suggested by the British diplomats in Beijing, was a result of his success in persuading the officials in London of the greater utility of his proposal in preserving British interests. The limited options available to Britain and Trench's shrewdness in exploiting the sovereign's uncertainty over the future of China contributed to the Governor's success in swaying the opinions of officials in London.
Long‐term morphodynamic evolution of a tidal embayment using a two‐dimensional, process‐based model
Authors: van der Wegen M. , Roelvink J. A.
Published: March 2008

The research objective is to investigate long‐term evolution of estuarine morphodynamics with special emphasis on the impact of pattern formation. Use is made of a two‐dimensional (2‐D), numerical, process‐based model. The standard model configuration is a rectangular 80 km long and 2.5 km wide basin. Equilibrium conditions of the longitudinal profile are analyzed using the model in 1‐D mode after 8000 years. Two‐dimensional model results show two distinct timescales. The first timescale is related to pattern formation taking place within the first decades and followed by minor adaptation according to the second timescale of continuous deepening of the longitudinal profile during 1600 years. The resulting longitudinal profiles of the 1‐D and 2‐D runs are similar apart from small deviations near the mouth. The 2‐D results correspond well to empirically derived relationships between the tidal prism and the channel cross section and between the tidal prism and the channel volume. Also, comparison between the current model results and data from the Western Scheldt estuary (in terms of bar length, hypsometry, percentage of intertidal area and values for the ratio of shoal volume and channel volume against the ratio of tidal amplitude and water depth) shows satisfying agreement. On the basis of the model results a relationship for a characteristic morphological wavelength was derived on the basis of the tidal excursion and the basin width and an exponentially varying function was suggested for describing a dimensionless hypsometric curve for the basin. Furthermore, special attention is given to an analysis of the numerical morphodynamic update scheme applied.
Library of Experimental Phase Relations (LEPR): A database and Web portal for experimental magmatic phase equilibria data
Authors: Hirschmann M. M. , Ghiorso M. S. , Davis F. A. , Gordon S. M. , Mukherjee S. , Grove T. L. , Krawczynski M. , Medard E. , Till C. B.
Published: March 2008

We describe the Library of Experimental Phase Relations (LEPR), which is a new Web‐based database of experiments pertaining to magmatic phase equilibria. The database includes information from experiments related to natural or near‐natural magmatic silicate phase equilibria. At present, the database includes more than 6,600 experiments with liquids ranging in composition from komatiite to rhyolite performed at temperatures between 500 and 2500°C and at pressures up to 27.5 GPa. Here we describe the organization of data and metadata that are included in the database as well as the database structure and the implementation of its Web interface. We discuss a number of challenges and considerations related to construction of a database of experimental data that influence both the selection and presentation of the information incorporated in LEPR. Finally, we survey durations of experiments in LEPR and discuss the relationship between duration and the probability of crystal‐liquid equilibrium in petrologic experiments.
An enhancement of the ionospheric sporadic‐E layer in response to negative polarity cloud‐to‐ground lightning
Authors: Davis C. J. , Lo Kin‐Hing
Published: March 2008

Lightning data, collected using a Boltek Storm Tracker system installed at Chilton, UK, were used to investigate the mean response of the ionospheric sporadic‐E layer to lightning strokes in a superposed epoch study. The lightning detector can discriminate between positive and negative lightning strokes and between cloud‐to‐ground (CG) and inter‐cloud (IC) lightning. Superposed epoch studies carried out separately using these subsets of lightning strokes as trigger events have revealed that the dominant cause of the observed ionospheric enhancement in the Es layer is negative cloud‐to‐ground lightning.
EuCRUST‐07: A new reference model for the European crust
Authors: Tesauro Magdala , Kaban Mikhail K. , Cloetingh Sierd A. P. L.
Published: March 2008

We present a new digital model (EuCRUST‐07) for the crust of Western and Central Europe and surroundings (35°N–71°N, 25°W–35°E). Available results of seismic reflection, refraction and receiver functions studies are assembled in an integrated model at a uniform grid (15′ × 15′). The model consists of three layers: sediments and two layers of the crystalline crust. Besides depth to the boundaries, we provide average P‐wave velocities in the upper and lower parts of the crystalline crust. The new model demonstrates large differences in the Moho depth compared to previous compilations, over ±10 km in some specific areas (e.g. the Baltic Shield). Furthermore, the velocity structure of the crust is much more heterogeneous than in previous maps. EuCRUST‐07 offers a starting point for numerical modeling of deeper structures by allowing correction for crustal effects beforehand and to resolve trade‐off with mantle heterogeneities.
Quality assessment of BRDF/albedo retrievals in MODIS operational system
Authors: Shuai Yanmin , Schaaf Crystal B. , Strahler Alan H. , Liu Jicheng , Jiao Ziti
Published: March 2008

We establish the quality of the MODIS BRDF/albedo retrieval process through the use of the Root Mean Squared Error (RMSE) and Weight of Determination (WoD). These measures are constructed during the inversion process to quantify the retrieval uncertainties. RMSE provides a deviation indicator of the model‐fits while WoD evaluates the confidence of the retrieval from given angular samplings. From a statistical analysis of retrievals over a range of surface types, we establish an upper range of thresholds (0.071, 0.097) for high quality RMSE, (1.431, 1.848) for WoD of Nadir Reflectance (assuming a 45° solar zenith angle, (2.122, 2.726) for WoD of White Sky Albedo. An investigation of inversions at typical biomes located at different latitude shows the retrievals are stable with respect to random uncertainty variations in the combined MODIS Terra and Aqua observations under the investigated sun‐view geometric angular distribution. The acquired ranges suggest improved thresholds should be implemented for future reprocessing versions of the 500m MODIS operational BRDF/albedo system.
A non‐hydrostatic Rhea
Authors: Mackenzie R. A. , Iess L. , Tortora P. , Rappaport N. J.
Published: March 2008

Radiometric data obtained during Cassini's close flyby of Rhea, on 26 November 2005, has been subject to several published analyses aiming to determine the satellite's mass and quadrupole gravity moments. Combining aspects of two of these analyses we present our best, unbiased estimates of the gravity field parameters and point out how the constraint of hydrostatic equilibrium adopted by previous analysts affects the results. We present solutions based on a broad range of geophysical assumptions, such as the presence of degree 3 and 4 gravity field constrained at different levels. The result is a balanced approach which describes our current knowledge of Rhea's gravity field. In the case of a gravity field limited to second degree harmonics the most reliable estimates are GM = 153.9398 ± 0.0008 km3 s−2, 106J2 = 931.0 ± 12.0, 106C22 = 237.2 ± 4.5, and 106S22 = 3.8 ± 3.8.
Role of gyration in the oceanic general circulation: Atlantic Ocean
Authors: Jiang Hua , Huang Rui Xin , Wang Hui
Published: March 2008

Wind‐driven gyres transport volume and heat in the meridional direction, which is an important component of the climate system. The contribution of wind‐driven gyres to both poleward volume and heat fluxes can be clearly identified from numerical models by a simple diagnostic tool; thus the central location, strength, and dynamical roles of wind‐driven circulation in the climatological mean state and decadal variability of the oceanic circulation can be examined in detail. This diagnostic tool was applied to the Simple Ocean Data Assimilation data generated from a numerical model, with data assimilation. Our analysis indicates the important contribution due to wind‐driven gyres and the strong decadal variability in the volume flux, heat flux, and central location of the wind‐driven gyres in the Atlantic Ocean.
Introduction of spatial smoothness constraints via linear diffusion for optimization‐based hyperspectral coastal ocean remote‐sensing inversion
Authors: Filippi Anthony M. , Kubota Toshiro
Published: March 2008

An optimization‐based, shallow water remote‐sensing inversion algorithm was recently developed by Lee et al. (1999) that simultaneously derives bottom depth and water column inherent optical properties. Only measured remote‐sensing reflectance is required as input, which is a noted advantage; however, the algorithm is sensitive to noise. Given the observation that bottom depth and optical properties generally change slowly over the spatial domain, we applied a smoothness assumption by modifying the Lee algorithm to accommodate a spatial smoothness constraint. Spatial constraints were introduced through a linear diffusion process. The new spatial constraint model retrievals were compared with those from the original Lee model, as well as from the original model plus smoothing performed as postprocessing. Synthetic and real field data experiments were performed. For the synthetic experiments the Lee method was the most sensitive to noise and posted the largest absolute and standard errors. For the field experiments, Portable Hyperspectral Imager for Low Light Spectroscopy Sensor (PHILLS) imagery was acquired over optically shallow water. An in situ acoustic sensor mounted on a towed Hyperspectral Tethered Spectral Radiometer Buoy (HTSRB) provided measured bottom depth transects, and remote‐sensing reflectance was HTSRB derived. Bathymetry estimates were validated in this research. Lee method bottom depth retrievals were more erratic than those generated via the other methods. Unlike postsmoothing the spatial constraint method corrected large deviations of the Lee method spanning several transect points. Overall, our spatial constraint method yielded the most accurate estimates and represents a significant improvement upon the Lee method. Mean absolute estimation errors for the Lee, postprocessing, and spatial constraint methods were 0.412, 0.389, and 0.335 m, respectively.
Compositional trends in aeolian dust along a transect across the southwestern United States
Authors: Goldstein Harland L. , Reynolds Richard L. , Reheis Marith C. , Yount James C. , Neff Jason C.
Published: March 2008

Aeolian dust strongly influences ecology and landscape geochemistry over large areas that span several desert ecosystems of the southwestern United States. This study evaluates spatial and temporal variations and trends of the physical and chemical properties of dust in the southwestern United States by examining dust deposited in natural depressions on high isolated surfaces along a transect from the Mojave Desert to the central Colorado Plateau. Aeolian dust is recognized in these depressions on the basis of textural, chemical, isotopic, and mineralogical characteristics and comparisons of those characteristics to the underlying bedrock units. Spatial and temporal trends suggest that although local dust sources are important to the accumulated material in these depressions, Mojave Desert dust sources may also contribute. Depth trends in the depressions suggest that Mojave sources may have contributed more dust to the Colorado Plateau recently than in the past. These interpretations point to the important roles of far‐traveled aeolian dust for landscape geochemistry and imply future changes to soil geochemistry under changing conditions in far‐distant dust source areas.
A hybrid three‐dimensional computational model of groundwater solute transport in heterogeneous media
Authors: Kuo Yuan‐Ching , Huang Liang‐Hsiung , Tsai Tung‐Lin
Published: March 2008

This study examines a new hybrid three‐dimensional computational solution for groundwater solute transport in a layered aquifer. In this study, the horizontal length scale of the computational domain, referring to the nature geometry, is assumed much larger than the vertical length scale. Thus the computation of solute transportation in the horizontal direction is more complex than the computation in the vertical direction. Using the Dupuit‐Forchheimer approximation of groundwater flow as a reference, this study employs the vertical/horizontal splitting (VHS) concept to divide the three‐dimensional solute transport equations into depth averaged (two‐dimensional) and vertical variation (one‐dimensional) equations. The two‐dimensional equations are processed via the so‐called finite analytic method, while the one‐dimensional equations are solved analytically. The three‐dimensional solute transport is effectively reduced to a hybrid three‐dimensional model by combining the two‐dimensional computations and the one‐dimensional analytical solutions. The resultant hybrid three‐dimensional method is capable of large computational time steps and large spatial grids and is thus suitable for simulating solute transport in large‐scale sites of layered aquifers with negligible spatial variation of both thickness and hydraulic properties within each layer, where traditional numerical schemes fall short of satisfying the requirements of both accuracy and efficiency. Nevertheless, the use of this method is necessarily restricted when (1) the site is extremely heterogeneous and thus cannot be treated as layers or (2) the flows in the aquifer and in the aquitard are highly three‐dimensional. This method is verified by analytical solutions as well as by the numerical model MT3D.
Spatial proximity, physical similarity, regression and ungaged catchments: A comparison of regionalization approaches based on 913 French catchments
Authors: Oudin Ludovic , Andréassian Vazken , Perrin Charles , Michel Claude , Le Moine Nicolas
Published: March 2008

Given the contradictory results from recent studies, this paper compares classical regionalization schemes of catchment model parameters over the wide range of hydroclimates found in France. To ensure the generality of the conclusions, we used two lumped rainfall‐runoff models applied to daily data over a large set of 913 French catchments. Three types of approaches were considered: regionalization using regression, regionalization based on spatial proximity and regionalization based on physical similarity. This comparison shows that in France, where a dense network of gauging stations is available, spatial proximity provides the best regionalization solution. The regression approach is the least satisfactory, with results very close to those obtained using one median parameter set for the whole country. The physical similarity approach is intermediary. However, the results obtained with these three methods lag far behind those obtained by full model calibration. Our results also show that some improvement could be made by combining spatial proximity and physical similarity, and that there is still considerable room for progress in the field of ungaged catchment modeling.
GabiPD: Gabi Primary Database - a plant integrative ‘omics’ database in GABI-FUTURE
Authors: Riaño-Pachón Diego Mauricio , Nagel Axel , Wagner Robert , Weber Elke , Kersten Birgit
Published: March 2008

GabiPD ("http://gabi.rzpd.de":http://gabi.rzpd.de) was established within GABI-I and further developed in GABI-II and constitutes a repository and analysis platform for a wide array of heterogeneous data arising from high throughput experiments developed by members of the GABI/WPG community. Currently, data from different fronts (genomics, transcriptomics, proteomics, metabolomics) are incorporated in GabiPD, representing 14 different biological species. Last year GabiPD moved to the Max Planck Institute of Molecular Plant Physiology. In the progressing GABI-FUTURE phase, the GabiPD team has been creating a more integrative data view, expanding the tools and information provided by our well-known GreenCards. Links to different species-specific (Arabidopsis thaliana so far) GABI-resources (e.g., Aramemnon, GABI-KAT) as well as external resources (e.g., ProMEX) are being added or updated. All data types (e.g., protein spots, clones) in GabiPD are pointing to the central Gene’s GreenCard, where gene information is retrieved from genome annotation projects or large UniGene sets provided by NCBI. Moreover, the GabiPD team will perform new types of data computations, like analysis of conserved domains in protein sequences.
Hartree-Fock exchange computed using the atomic resolution of the identity approximation
Authors: Sodt Alex , Head-Gordon Martin
Published: March 2008

In this work, we apply the atomic resolution of the identity (ARI) fitting approximation to the computation of Hartree-Fock exchange. The ARI approximation is a local modification of the RI approximation that produces an energy which is differentiable with respect to nuclear motion, unlike other local applications of RI. We justify empirically the use of locality and present timing comparisons of ARI, RI, and exact computation for one-, two-, and three-dimensional carbon systems. ARI is found to reduce significantly the cost of RI for large systems, while retaining accuracy.
Dynamics at conical intersections: The influence of O–H stretching vibrations on the photodissociation of phenol
Authors: Hause Michael L. , Heidi Yoon Y. , Case Amanda S. , Crim F. Fleming
Published: March 2008

Comparing the recoil energy distributions of the fragments from one-photon dissociation of phenol-d5 with those from vibrationally mediated photodissociation shows that initial vibrational excitation strongly influences the disposal of energy into relative translation. The measurements use velocity map ion imaging to detect the H-atom fragments and determine the distribution of recoil energies. Dissociation of phenol-d5 molecules with an initially excited O–H stretching vibration produces significantly more fragments with low recoil energies than does one-photon dissociation at the same total energy. The difference appears to come from the increased probability of adiabatic dissociation in which a vibrationally excited molecule passes around the conical intersection between the dissociative state and the ground state to produce electronically excited phenoxyl-d5 radicals. The additional energy deposited in electronic excitation of the radical reduces the energy available for relative translation.
Intermediate motions as studied by solid-state separated local field NMR experiments
Authors: deAzevedo Eduardo Ribeiro , Saalwachter Kay , Pascui Ovidiu , de Souza André A. , Bonagamba Tito J. , Reichert Detlef
Published: March 2008

In this report, the application of a class of separated local field NMR experiments named dipolar chemical shift correlation (DIPSHIFT) for probing motions in the intermediate regime is discussed. Simple analytical procedures based on the Anderson–Weiss (AW) approximation are presented. In order to establish limits of validity of the AW based formulas, a comparison with spin dynamics simulations based on the solution of the stochastic Liouville–von-Neumann equation is presented. It is shown that at short evolution times (less than 30% of the rotor period), the AW based formulas are suitable for fitting the DIPSHIFT curves and extracting kinetic parameters even in the case of jumplike motions. However, full spin dynamics simulations provide a more reliable treatment and extend the frequency range of the molecular motions accessible by DIPSHIFT experiments. As an experimental test, molecular jumps of imidazol methyl sulfonate and trimethylsulfoxonium iodide, as well as the side-chain motions in the photoluminescent polymer poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene], were characterized. Possible extensions are also discussed.
Multireference Brillouin–Wigner coupled cluster method with singles, doubles, and triples: Efficient implementation and comparison with approximate approaches
Authors: Demel Ondřej , Pittner Jiří
Published: March 2008

We have developed an efficient implementation of the multireference Brillouin–Wigner coupled cluster method with full iterative treatment of connected singles, doubles, and triples. Its computational costs are too high for applications to larger molecules; however, it can be used as a useful tool for benchmarking approximate methods. Performance of the method has been tested on the ground and low-lying excited states of the oxygen molecule and on the singlet-triplet gap in methylene; the results are in good agreement with experimental data.
Hydrogen detachment of the hydrated hydrohalogen acids upon attaching an excess electron
Authors: Lee Han Myoung , Kim Kwang S.
Published: March 2008

High level ab initio calculations are employed to investigate the excess electron attachment to the hydrated hydrohalogen acids. The excess electron leads to the dissociation of hydrogen halide acids, which results in the release of a hydrogen radical. Neutral HCl, HBr, and HI are dissociated by tetrahydration. Upon binding an excess electron, these hydrated hydrohalogen acids show that (i) the H–X bond strength weakens with redshifted H–X stretching frequencies, (ii) HX can have a bound-electron state, a dissociated structure, or a zwitter-ionic structure, and (iii) HCl∕HBr is dissociated by tri/mono-hydration, while HI is dissociated even without hydration. This dissociation is in contrast to the case of electron attachment to hydrated hydrogen fluoric acids for which HF is not dissociated by more than ten water molecules.
Phosphorescence excitation spectrum of the T1(n,π*)←S transition of 4H-pyran-4-one
Authors: Hoffelt Laura M. , Springer Mitchell G. , Drucker Stephen
Published: March 2008

The phosphorescence excitation (PE) spectrum of 4H-pyran-4-one (4PN) vapor at 40–50°C was recorded near 366nm. The most intense vibronic feature in this region of the spectrum is the T1(n,π*)←S0 origin band. The value of ν0 for the 000 transition was determined to be 27291.5cm−1 by comparing the observed spectrum to a simulation in the T1←S0 origin-band region. Attached to the origin band in the PE spectrum are several Δv=0 sequence bands involving low-frequency ring modes. From the positions of these bands, together with the known ground-state combination differences, fundamental frequencies for ν18′ (ring bending), ν13′ (ring twisting), and ν10′ (in-plane ring deformation) in the T1(n,π*) excited state were determined to be 126, 269, and 288cm−1, respectively. These values represent drops of 15%, 32%, and 43%, compared to the respective fundamental frequencies in the S0 state. The changes in these ring frequencies indicate that the effects of T1(n,π*)←S0 excitation extend beyond the nominal carbonyl chromophore and involve the conjugated ring atoms as well. The delocalization may be more extensive for T1(n,π*) than for S1(n,π*) excitation.
Magnetic force microscopy study of magnetic stripe domains in sputter deposited Permalloy thin films
Authors: Amos Nissim , Fernandez Robert , Ikkawi Rabee , Lee Beomseop , Lavrenov Andrey , Krichevsky Alexander , Litvinov Dmitri , Khizroev Sakhrat
Published: March 2008

A magnetic force microscopy based study on the formation of stripe domains in Permalloy (Ni80Fe20) thin films is presented. Our results show that the critical thickness for stripe domain initiation depended on the sputtering rate, the substrate temperature, and the film thickness. Beyond the stripe domain formation, an increase of the period of a highly ordered array of stripe domains was evident with increasing film thickness. Thin films sputtered at room temperature with thickness variation between ∼80 and ∼350nm exhibited square-root growth dependency on stripe domains periodicity from ∼150to∼380nm, respectively. Above a certain thickness, the domain period decreased and the periodicity deteriorated with the array becoming more random, which is a strong indicator of relatively high structural perpendicular anisotropy. To illustrate, Permalloy sputtered at 100°C initially showed linear dependence in stripe domain periodicity growth up until ∼650nm thick films. The magnetic stripe domain structure began breaking down for thicker Permalloy films. Our data also suggested that the perpendicular anisotropy responsible for the formation of stripe domains might have resulted from strain-caused magnetostriction and the thin-film microstructure shape effect.
Probing multilayer spintronic structures with photoelectron and x-ray emission spectroscopies excited by x-ray standing waves (invited)
Authors: Yang S.-H. , Sell B. C. , Fadley C. S.
Published: March 2008

We discuss a newly developed x-ray standing-wave∕wedge (swedge) method for probing the composition, magnetization, and electronic densities of states in buried interfaces and layers in spintronic nanostructures. In work based on photoemission, this method has permitted determining concentration and magnetization profiles through giant magnetoresistive (GMR) and magnetic tunnel junctions structures, as well as individual layer densities of states near the Fermi level in a tunnel junction. Using x-ray emission and resonant inelastic x-ray scattering for detection has permitted probing deeper layers and interfaces in a GMR structure. Various future applications of this method in nanomagnetism are suggested, including using more energetic hard x-ray standing waves so as to probe more deeply below a surface and standing-wave excitation in spectromicroscopy to provide depth sensitivity.
Thickness of the pinned layer as a controlling factor in domain wall formation during training in IrMn-based spin valves
Authors: Park Jun , Watson Shannon M. , Furjanic C. M. , Draganova D. K. , Eisenberg S. D. , Tighe D. J. , Kienzle P. A. , Carey M. J. , Borchers J. A. , Sparks P. D. , Eckert J. C.
Published: March 2008

Studies of CoFe-based spin valves with antiferromagnetic IrMn layers as thin as 1.6nm have demonstrated that a domain wall parallel to the surface develops in the pinned layer after training at the magnetoresistance (MR) maximum. To investigate the effects of domain wall formation on the MR, we have studied the depth profile of the vector magnetization in comparable spin valves, with pinned ferromagnetic (FM) layer thicknesses, from 1to15nm, using polarized neutron reflectivity. At the maximum MR achieved after training, the antiparallel magnetization of the pinned layer, in a 2nm sample, is reduced to 5% of its saturation value, suggesting the formation of domain walls perpendicular to the surface. In a 9nm sample, the pinned layer magnetization is instead canted away from the field at the MR maximum. A transition from perpendicular to parallel domain wall formation occurs for pinned layer thicknesses greater than 4nm, and the magnitude of the maximum MR subsequently depends on the type of domain wall that develops.
Reversal mechanisms in alternating width nanowires
Authors: Goolaup S. , Adeyeye A. O. , Singh N. , Gubbiotti G.
Published: March 2008

The magnetization reversal mechanism in closely packed alternating width nanowires consisting of two sets of Ni80Fe20 nanowires of different widths w1=330nm and w2=580nm, alternated in an array is presented. For all the wire thicknesses studied, the reversal mechanism of the alternating width wire array is markedly different from the homogeneous width wire array. The magnetization reversal mechanism of the alternating width nanowires is due to the distinct switching fields of the two wires constituting the array, even though the wires are closely packed.
Control of microstructure in (001)-orientated FePt–SiO2 granular films
Authors: Wu Yun-Chung , Wang Liang-Wei , Lai Chih-Huang , Chang Ching-Ray
Published: March 2008

Highly ordered L10 FePt–SiO2 granular films with a (001)-preferred orientation were obtained by depositing atomic-scale [Fe∕Pt∕SiO2(tox)] multilayers on glass substrates and subsequently annealing multilayers at the temperature of as low as 350°C. The tox value plays an important role on both microstructure and magnetic properties. The average grain sizes of samples A, B, and C (tox=0.11,0.28,0.56) are 12.12, 15.46, and 5.14nm, respectively, and the corresponding perpendicular coercivities are 6800, 5550, and 7700Oe. Due to different microstructures, samples show distinct coercivity dependence on annealing time.
Optical control over electron g factor and spin decoherence in (In,Ga)As∕GaAs quantum dots
Authors: Rietjens J. H. H. , Quax G. W. W. , Bosco C. A. C. , Nötzel R. , Silov A. Yu. , Koopmans B.
Published: March 2008

We have studied the dependence of the electron in-plane g factor and spin decoherence time on the built-in electric field (Ei) at the position of a single layer of self-assembled (In,Ga)As∕GaAs quantum dots (QDs). Control of Ei is achieved by inducing screening charges in a p-i-n GaAs matrix with a continuous wave (cw) laser. Using a time-resolved pump-probe technique to measure the spin dynamics via the magneto-optical Kerr effect, we observe a large hole spin decoherence time of 440ps. Measurements as function of the cw laser power and, thus, of Ei show that the electron spin decay time in the QDs depends strongly on Ei and decreases from 310to110ps with increasing Ei. We attribute this effect to increasing tunneling rates of electrons out of the QDs at high Ei. We observe a slight increase of the electron g factor from 0.40±0.03 to 0.46±0.04 with increasing Ei, which might be a result of a changing wavefunction as a result of a different confinement potential due to Ei.
Relationship between surface coverage and end group functionality of molecularly thin perfluoropolyether films
Authors: Chen Haigang , Jhon Myung S.
Published: March 2008

The relationship between surface coverage and film thickness for perfluoropolyether (PFPE) films with different functional end groups was investigated by measuring the dispersive surface energy. It was found that the strength of end group functionality played an important role in the surface coverage; i.e., PFPE with the stronger end group functionality has the smaller surface coverage. Molecular dynamics simulations with a bead-spring model were employed to investigate the conformation of PFPE films, where the anisotropic radii of gyration were analyzed as a function of the strength of end group functionality. It was found that PFPE became flatter if the strength of end group functionality decreased, which, in turn, increased the surface coverage.
Spin transfer precessional dynamics in Co60Fe20B20 nanocontacts
Authors: Rippard W. H. , Pufall M. R. , Schneider M. L. , Garello K. , Russek S. E.
Published: March 2008

We report on the precessional dynamics in spin transfer oscillators having Co60Fe20B20 free layers as a function of annealing time at 225°C. Repeated annealing reduces the critical current Ic by roughly a factor of 3 and increases the tunability of the oscillation frequency with current df∕dI. The decrease in Ic correlates with an increasing giant magnetoresistance (GMR) during the first 3h of annealing. For longer times, df∕dI continues to increase, although the GMR does not. The variations in the macroscopic Co60Fe20B20 magnetization parameters and contact dimensions with annealing are not sufficient to account for the later changes.
Effect of Ni–Zn ferrite on bandwidth and radiation efficiency of embedded antenna for mobile phone
Authors: Bae S. , Hong Y. K. , Lyle A.
Published: March 2008

Performance of inverted F meander antenna with a lossy ferrite film was investigated and compared to air-core antenna with the same design. We have fabricated ferrite film antenna using 3μm thick plated Ni0.21Zn0.45Fe2.34O4. Loss tanδμ of the plated ferrite was about 1.5 around 500MHz. It was found that bandwidth significantly increased by the use of lossy ferrite, while radiation efficiency (RE) decreased. However, the RE increases as the thickness of lossy ferrite film decreases below 10μm. The fractional bandwidth of ferrite film antenna was found to be 13.8%, which shows a 431% as compared to an air-core antenna. The center frequency (fc) for ferrite film antenna decreased from 584to534MHz of the air-core antenna. This implies 7.5% decrease in the fc, while the gain of the ferrite was not much lower than the air-core antenna. Lossy ferrite thin film has been found to be effective in broadening of bandwidth, while retaining an acceptable gain.
Anomalous magnetic responsiveness of giant magnetoresistive heads under specific electromagnetic interference frequencies using quasistatic tester
Authors: Kruesubthaworn Anan , Pratoomthip Aphaiphak , Siritaratiwat Apirat , Ungvichian Vichate
Published: March 2008

The giant magnetoresistive (GMR) heads have been used in the computer industry for decade. Recently, the anomalous performance caused by cell phones or external electromagnetic interference (EMI) is reported [V. Kraz and A. Wallash, J. Electrost. 54, 39 (2002)]; [Kruesubthaworn et al., J. Magn. Magn. Mater. 316, e142 (2007)] This prompts an experimental study of an anomalous magnetic disturbance to the heads under ascending and descending frequency variations. The rf generator with predetermined output is set for 30–1000MHz swept frequency in both directions, with the antenna being horizontal and vertical orientations. Five quasistatic tester (QST) parameters; magnetoresistive (MR) resistance, MR amplitude, asymmetry, Barkhausen noise, and hysteresis are used as markers in the EMI sensitivity study of head gimbal assembly. It is found that the worst change of MR amplitude is 10.2% (marginally over the norm), which occurs at 910MHz during ascending swept frequency and horizontal polarization. The largest variation of hysteresis parameter is 21.8% (1.5 times over the norm) during 940MHz descending swept frequency and horizontal polarization. The remaining parameters have small effects, less than 6.5%. During the EMI exposure, QST transfer curves show significant departure from the frequencies of 500–580, 700–850, and 900–1000MHz. However, the trace separation is returned back to the preexposure condition. The scanning electron microscope evaluation of the GMR head after the exposure appears to be normal. Therefore, these parameter disturbances are not adequate to cause visible damage, but since some parameters are over the manufacturing accepted QST values, it may cause a latently failed head.
Crystalline structure and magnetic properties of Fe2CrSi Heusler alloy films: New ferromagnetic material for high-performance magnetic random access memory
Authors: Yoshimura S. , Asano H. , Nakamura Y. , Yamaji K. , Takeda Y. , Matsui M. , Ishida S. , Nozaki Y. , Matsuyama K.
Published: March 2008

A new Heusler alloy, Fe2CrSi, which has high spin polarization (P), low saturation magnetization (Ms), and a low Curie temperature (TC), was investigated in order to fabricate high-performance magnetic tunnel junctions (MTJs) with a high tunnel magnetoresistance ratio and with low critical current for the spin-transfer switching method, or a low switching field for the thermally assisted magnetization reversal technique. The main results are as follows: (1) P and the magnetic moment of Fe2CrSi with an L21 structure were 0.98 and 1.98μB∕f.u., respectively, according to density of states calculations. (2) Fe2CrSi films show the (100) orientation with a B2 structure on a MgO substrate upon a thermal treatment with optimum temperature and duration. (3) Fe2CrSi films have Ms and TC values of 385emu∕cm3 and 630K, respectively. (4) The (100) oriented epitaxial MTJs are produced with Fe2CrSi films fabricated with the optimized thermal treatment condition. It is found that the Fe2CrSi Heusler alloy films are a suitable ferromagnetic material for high-performance magnetic random access memory.
Spin torque switching in perpendicular films at finite temperature
Authors: Zhu Ru , Visscher P. B.
Published: March 2008

We show how the phase diagram for spin torque switching in the case of perpendicular anisotropy is altered at nonzero temperature. The hysteresis region in which the parallel and antiparallel states coexist shrinks, and a new region of telegraph noise appears. In a small sample, the region of coexistence of a precessional and parallel state can disappear entirely. We show that the phase diagram for both zero and nonzero temperatures can be understood and calculated by plotting an effective energy as a function of angle. A combinatorial analysis is useful for systematically describing the phase diagram.
Neutron emission generated during wire array Z-pinch implosion onto deuterated fiber
Authors: Klir D. , Kravarik J. , Kubes P. , Rezac K. , Anan’ev S. S. , Bakshaev Yu. L. , Blinov P. I. , Chernenko A. S. , Kazakov E. D. , Korolev V. D. , Meshcherov B. R. , Ustroev G. I. , Juha L. , Krasa J. , Velyhan A.
Published: March 2008

The implosion of both cylindrical and conical wire arrays onto a deuterated polyethylene fiber was studied on the S-300 pulsed power generator [A. S. Chernenko et al., Proceedings of the 11th International Conference on High Power Particle Beams (Academy of Science of Czech Republic, Prague, 1996), p. 154]. Neutron measurements were used to obtain information about acceleration of fast deuterons. An average neutron yield approached 109 on the current level of 2MA. In the case of conical wire arrays, side-on neutron energy spectra peaked at 2.48±0.05MeV with 450±100keV full width at half-maximum. In the downstream direction, the peak neutron energy and the width of a neutron spectrum were 2.65±0.10MeV and 350±100keV, respectively. The total number of fast deuterons was 1015 and their average kinetic energy was about 150keV. Most of the deuterons were directed toward the cathode. The broad width of neutron spectra in the side-on direction implied a high radial component of deuteron velocity. With regard to the emission time, neutron pulses temporally correlated with hard x rays and also with measured voltage. The neutron emission lasted on average 30±5ns and it was observed during the stagnation and at the beginning of the expansion of a plasma column. At this moment, the plasma impedance reached 0.2–0.4Ω. In the post-stagnation phase, this value was formed significantly by enhanced plasma resistance. Similar experimental results were observed also with cylindrical wire arrays imploding onto a deuterated fiber.