bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical correction of the medial rotation contracture in obstetric brachial plexus palsy
Authors: Nath R. K. , Lyons A. B. , Melcher S. E. , Paizi M.
Published: December 2007

The medial rotation contracture caused by weak external rotation secondary to obstetric brachial plexus injury leads to deformation of the bones of the shoulder. Scapular hypoplasia, elevation and rotation deformity are accompanied by progressive dislocation of the humeral head. Between February and August 2005, 44 children underwent a new surgical procedure called the ‘triangle tilt’ operation to correct this bony shoulder deformity. Surgical levelling of the distal acromioclavicular triangle combined with tightening of the posterior glenohumeral capsule (capsulorrhaphy) improved shoulder function and corrected the glenohumeral axis in these patients. The posture of the arm at rest was improved and active external rotation increased by a mean of 53° (0° to 115°) in the 40 children who were followed up for more than one year.

There was a mean improvement of 4.9 points (1.7 to 8.3) of the Mallet shoulder function score after surgical correction of the bony deformity.
Comments on Preference Revelation for Public Policy Decisions
Authors: Rothenberg Jerome
Published: December 2007

1. These are good papers. I found them rewarding. I shall have some remarks for all three, but most of this discussion refers to the Tideman and Clark papers (not, however, for reasons of quality). This Tideman paper is an exceptionally full survey, and very well done. There is solid analysis and reasonable judgement. It is quite a useful work. The Clark paper is most helpful to the reader in providing a great deal of background very clearly, The situational distinctions among the dimensions of public policy and citizen attitudes are especially illuminating.

Both papers explicitly specify criteria for evaluating different public decision rules. In view of the fact that these are often only implicit in public policy analysis, a potentially highly misleading procedure when there is such a variety of rules to examine, this overtness is an important strength.

Besides these rather similar general attractions, the Clark paper emphasizes that ‘measuring instruments … (should be) … only as precise and complex as necessary for the decision at hand’. Since precision and complexity entail sometimes considerable cost to investigators or policy officials, this inherently economic principle is hard to resist.
Selection criteria of Eucalyptus globulus Labill. for production of chemithermomechanical pulps (CTMP)
Authors: Kojima Yasuo , Isaji Shinichi , Yoon Seung-Lak , Ona Toshihiro
Published: December 2007

Utilization of rapidly growing trees, such as eucalypts, for high-yield mechanical pulps is limited by low brightness owing to high contents of alkali and neutral extractives. Wood supply problems have developed in many areas of the world and new sources of high-yield pulp are needed. Ten Eucalyptus globulus trees were selected from two plantation sites to evaluate suitability as raw material for high-quality and high-yield pulp. Chemithermomechanical pulp (CTMP) was prepared from tree chips pretreated with sodium sulfite prior to refining. Characteristics of the CTMP were correlated with chemical and physical properties of the wood. There was a linear relationship between the content of alcohol-benzene extractives in wood and CTMP brightness. Klason lignin content in wood was inversely correlated with pulp sheet density, which is an important characteristic affecting the physical properties of pulp. The content of alkali extractives were inversely correlated with pulp yields. Color reversion was tested by exposing CTMP sheets to heat and light. Heat-induced yellowing of CTMP was of a low level and satisfied requirements for printing paper. The rate of yellowing was inversely associated with extractives and can be reduced by antioxidants.
A Case for Professional Level Staffing for Microforms
Authors: Madsen Debora
Published: December 2007

Microforms in today's academic libraries appear to be understaffed and left behind in the electronic age. At best, microform collections experience benign neglect. At worst, administrators view microforms as an obsolete format that has little merit in today's digital world. Despite the fact that microform collections in many academic libraries represent a large financial investment, staffing is almost entirely by paraprofessionals and students. In some of the largest libraries, service for microform collections consists of machine help only.
Statewide Digitization Planners Conference Summary Report
Authors: Lytle Amy
Published: December 2007

For several years, a group of leaders representing statewide and large regional collaborative digitization programs has been meeting at the American Library Association (ALA) Annual and Mid-winter conferences. These 1.5-hour meetings include brief presentations on topics of mutual interest, such as technical issues, emerging standards, and funding. These meetings also serve as a forum for sharing program updates, including concerns and achievements. The usefulness of these meetings, and the desire to extend participation to program representatives who do not normally attend the ALA conferences, especially staff from museums and historical societies, led to discussion of holding a national conference to focus on issues that large-scale collaborative digitization projects have in common.
Prenatal and Adolescent Exposure to Tobacco Smoke Modulates the Development of White Matter Microstructure
Authors: Jacobsen Leslie K. , Picciotto Marina R. , Heath Christopher J. , Frost Stephen J. , Tsou Kristen A. , Dwan Rita A. , Jackowski Marcel P. , Constable Robert T. , Mencl W. Einar
Published: December 2007

Prenatal exposure to maternal smoking has been linked to cognitive and auditory processing deficits in offspring. Preclinical studies have demonstrated that exposure to nicotine disrupts neurodevelopment during gestation and adolescence, possibly by disrupting the trophic effects of acetylcholine. Given recent clinical and preclinical work suggesting that neurocircuits that support auditory processing may be particularly vulnerable to developmental disruption by nicotine, we examined white matter microstructure in 67 adolescent smokers and nonsmokers with and without prenatal exposure to maternal smoking. The groups did not differ in age, educational attainment, IQ, years of parent education, or symptoms of inattention. Diffusion tensor anisotropy and anatomical magnetic resonance images were acquired, and auditory attention was assessed, in all subjects. Both prenatal exposure and adolescent exposure to tobacco smoke was associated with increased fractional anisotropy (FA) in anterior cortical white matter. Adolescent smoking was also associated with increased FA of regions of the internal capsule that contain auditory thalamocortical and corticofugal fibers. FA of the posterior limb of the left internal capsule was positively correlated with reaction time during performance of an auditory attention task in smokers but not in nonsmokers. Development of anterior cortical and internal capsule fibers may be particularly vulnerable to disruption in cholinergic signaling induced by nicotine in tobacco smoke. Nicotine-induced disruption of the development of auditory corticofugal fibers may interfere with the ability of these fibers to modulate ascending auditory signals, leading to greater noise and reduced efficiency of neurocircuitry that supports auditory processing.
Electrical Stimulation of the Midbrain for Hearing Restoration: Insight into the Functional Organization of the Human Central Auditory System
Authors: Lim Hubert H. , Lenarz Thomas , Joseph Gert , Battmer Rolf-Dieter , Samii Amir , Samii Madjid , Patrick James F. , Lenarz Minoo
Published: December 2007

The cochlear implant can restore speech perception in patients with sensorineural hearing loss. However, it is ineffective for those without an implantable cochlea or a functional auditory nerve. These patients can be implanted with the auditory brainstem implant (ABI), which stimulates the surface of the cochlear nucleus. Unfortunately, the ABI has achieved limited success in its main patient group [i.e., those with neurofibromatosis type 2 (NF2)] and requires a difficult surgical procedure. These limitations have motivated us to develop a new hearing prosthesis that stimulates the midbrain with a penetrating electrode array. We recently implanted three patients with the auditory midbrain implant (AMI), and it has proven to be safe with minimal movement over time. The AMI provides loudness, pitch, temporal, and directional cues, features that have shown to be important for speech perception and more complex sound processing. Thus far, all three patients obtain enhancements in lip reading capabilities and environmental awareness and some improvements in speech perception comparable with that of NF2 ABI patients. Considering that our midbrain target is more surgically exposable than the cochlear nucleus, this argues for the use of the AMI as an alternative to the ABI. Fortunately, we were able to stimulate different midbrain regions in our patients and investigate the functional organization of the human central auditory system. These findings provide some insight into how we may need to stimulate the midbrain to improve hearing performance with the AMI.
How Pleasant and Unpleasant Stimuli Combine in Different Brain Regions: Odor Mixtures
Authors: Grabenhorst Fabian , Rolls Edmund T. , Margot Christian , da Silva Maria A. A. P. , Velazco Maria Ines
Published: December 2007

Many affective stimuli are hedonically complex mixtures containing both pleasant and unpleasant components. To investigate whether the brain represents the overall affective value of such complex stimuli, or the affective value of the different components simultaneously, we used functional magnetic resonance imaging to measure brain activations to a pleasant odor (jasmine), an unpleasant odor (indole), and a mixture of the two that was pleasant. In brain regions that represented the pleasantness of the odors such as the medial orbitofrontal cortex (as shown by activations that correlated with the pleasantness ratings), the mixture produced activations of similar magnitude to the pleasant jasmine, but very different from the unpleasant indole. These regions thus emphasize the pleasant aspects of the mixture. In contrast, in regions representing the unpleasantness of odors such as the dorsal anterior cingulate and midorbitofrontal cortex the mixture produced activations that were relatively further from the pleasant component jasmine and closer to the indole. These regions thus emphasize the unpleasant aspects of the mixture. Thus mixtures that are found pleasant can have components that are separately pleasant and unpleasant, and the brain can separately and simultaneously represent the positive and negative hedonic value of a complex affective stimulus that contains both pleasant and unpleasant olfactory components. This type of representation may be important for affective decision making in the brain in that separate representations of different affective components of the same sensory stimulus may provide the inputs for making a decision about whether to choose the stimulus or not.
Role of obesity in colorectal carcinogenesis
Authors: Hagymási Krisztina , Tulassay Zsolt
Published: December 2007

Az elhízás a második leggyakoribb megelőzhető halálok. A szív- és érrendszeri betegségek, a 2-es típusú cukorbetegség, a daganatos betegségek, valamint az idő előtti halálozás kockázatát növeli. A túlsúly és az elhízás a daganatok okozta halálozás 14, illetve 20%-áért felelős férfiakban, illetve nőkben. A szerzők az elhízás, a metabolikus szindróma, illetve a kapcsolódó anyagcsere-eltérések, valamint a vastagbéldaganatok közötti összefüggést tekintik át. Ismertetik a gyulladás, a hyperinsulinaemia, az inzulinszerű növekedési faktor-I és az adipokinek szerepét a vastagbélrák kialakulásában.
Multidimensionally stimuli‐responsive phase transition of aqueous solutions of poly((N,N‐dimethylamino)ethyl methacrylate) and poly(N,N‐dimethyl‐N‐(methacryloyl)ethyl ammonium butane sulfonate)
Authors: Gao Jun , Zhai Guangqun , Song Yan , Jiang Bibiao
Published: December 2007

Free radical polymerization of N,N‐(dimethylamino)ethyl methacrylate and N,N‐dimethyl‐N‐(methacryloyloxy)ethyl ammonium butane sulfonate was carried out to prepare PDMAEMA and PDMABS. Proton nuclear magnetic resonance spectroscopy indicated that both PDMAEMA and PDMABS exhibited an electrolyte‐responsive conformational dynamics in D2O of different ionic strength. PDMAEMA, as a polybase, and PDMABS, as a polysulfobetaine, exhibited a series of multidimensional stimuli‐responsive phase transition behaviors. Adding NaCl would decrease the phase transition temperature (TPT) of their aqueous mixtures, because of polyelectrolyte effect for PDMAEMA and anti‐polyelectrolyte effect for PDMABS, respectively. For PDMAEMA, a low pH would facilitate the dissolution; on the other hand, for PDMABS, a maximum TPT was achieved in neutral media. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Stereoselective determination of demethyl‐ and didemethyl‐citalopram in rat plasma and brain tissue by liquid chromatography with fluorescence detection using precolumn derivatization
Authors: Millán S. , Goicolea M. A. , Sánchez A. , Gómez‐Caballero A. , Sampedro M. C. , Unceta N. , Barrio R. J.
Published: December 2007

A rapid and sensitive HPLC enantioselective method with fluorescence detection was developed to determine (−)‐(R) and (+)‐(S) enantiomers of the metabolites of citalopram, demethyl‐ and didemethyl‐citalopram in plasma and brain tissue. This assay involves pre‐column chiral derivatization with (−)‐(R)‐1‐(1‐naphthyl)ethyl isocyanate followed by separation on a normal‐phase silica column. The developed liquid–liquid extraction procedure permits quantitative determination of analytes with recoveries ranged between 81 and 88% with intra‐ and inter‐day relative standard deviations less than 10.5%. Linearity was obtained over the concentration range 5–1000 ng/mL and 100–10,000 ng/g for spiked drug‐free plasma and brain tissue, respectively, with detection limits lower than 2.1 ng/mL and 42.8 ng/g. Copyright © 2007 John Wiley & Sons, Ltd.
Recent progress in the development of derivatization reagents having a benzofurazan structure
Authors: Santa Tomofumi , Fukushima Takeshi , Ichibangase Tomoko , Imai Kazuhiro
Published: December 2007

Chemical derivatization is often used to enhance the detectability of the target compounds and to improve the separation efficiency in high‐performance liquid chromatography (HPLC). In this review, we describe the recent progress in the development of derivatization reagents having a benzofurazan structure, namely, the fluorogenic reagents, water‐soluble reagents, reagents for the analysis of peptides and proteins, and reagents for mass spectrometric detection. The application of these reagents to bio‐samples is also briefly described. Copyright © 2007 John Wiley & Sons, Ltd.
Molecular Models of the Interface between Anterior Pharynx‐Defective Protein 1 (APH‐1) and Presenilin Involving GxxxG Motifs
Authors: Jozwiak Krzysztof , Krzysko Krystiana A. , Bojarski Lukasz , Gacia Magdalena , Filipek Slawomir
Published: December 2007

γ‐Secretase is an integral membrane protease, which is a complex of four membrane proteins. Improper functioning of γ‐secretase was found to be critical in the pathogenesis of Alzheimer’s disease. Despite numerous efforts, the structure of the protease as well as its proteolytic mechanism remains poorly understood. In this work we constructed a model of interactions between two proteins forming γ‐secretase: APH‐1 and presenilin. This interface is based on a highly conserved GxxxGxxxG motif in the APH‐1 protein. It can form a tight contact with a small‐residue AxxxAxxxG motif in presenilin. Here, four binding modes based on similar structures involving GxxxG motifs in glycophorin and aquaporin were proposed and verified. The resulting best model employs antiparallel orientations of interacting helices and is in agreement with the currently accepted topology of both proteins. This model can be used for further structural characterization of γ‐secretase and its components.
Extending the Scope of Singlet‐State Spectroscopy
Authors: Sarkar Riddhiman , Ahuja Puneet , Moskau Detlef , Vasos Paul R. , Bodenhausen Geoffrey
Published: December 2007

Different decoupling sequences are tested—using various shaped radio‐frequency (RF) pulses—to achieve the longest possible lifetimes of singlet‐state populations over the widest possible bandwidths, that is, ranges of offsets and relative chemical shifts of the nuclei involved in the singlet states. The use of sinc or refocusing broadband universal rotation pulses (RE‐BURP) for decoupling during the intervals where singlet‐state populations are preserved allows one to extend the useful bandwidth with respect to prior state‐of‐the‐art methods based on composite‐pulse WALTZ decoupling. The improved sinc decoupling sequences afford a more reliable and sensitive measure of the lifetimes of singlet states in pairs of spins that have widely different chemical shifts, such as the two aromatic protons H5 and H6 in uracil. Similar advantages are expected for nucleotides in RNA and DNA. Alternative approaches, in particular frequency‐modulated decoupling sequences, also appear to be effective in preserving singlet‐state populations, even though the profiles of the apparent relaxation rate constants as a function of the offset are somewhat perturbed. The best decoupling sequences prove their utility in sustaining longer lifetimes of singlet states than previously achieved for the side‐chain tyrosine protons in bovine pancreatic trypsin inhibitor (BPTI) at 600 MHz (14.1 T), where the differences of chemical shifts between coupled protons are a challenge.
The inpatient management of physical activity in young people with anorexia nervosa
Authors: Davies Sarah , Parekh Komal , Etelapaa Kaisa , Wood David , Jaffa Tony
Published: December 2007

This study investigates the management of physical activity in young inpatients with anorexia nervosa. Through telephone interviews and postal surveys inpatient units across the UK were asked about written documents regarding physical activity management, how they viewed healthy exercise, how they assessed physical fitness to engage in activity, the management approaches taken, provision of education and support around this issue and range of activities provided. Results indicated that a variety of approaches were taken, with little consensus between units, although the majority of approaches did involve some form of restriction, frequently determined by weight criteria. There were few substantial written documents to guide practice and a range of interpretations of healthy exercise. The findings are discussed and suggestions made for research to explore this area further and to inform the development of effective interventions. Copyright © 2007 John Wiley & Sons, Ltd and Eating Disorders Association.
A new computational framework for multi‐scale ocean modelling based on adapting unstructured meshes
Authors: Piggott M. D. , Gorman G. J. , Pain C. C. , Allison P. A. , Candy A. S. , Martin B. T. , Wells M. R.
Published: December 2007

A new modelling framework is presented for application to a range of three‐dimensional (3D) multi‐scale oceanographic problems. The approach is based upon a finite element discretization on an unstructured tetrahedral mesh which is optimized to represent highly complex geometries. Throughout a simulation the mesh is dynamically adapted in 3D to optimize the representation of evolving solution structures. The adaptive algorithm makes use of anisotropic measures of solution complexity and a load‐balanced parallel mesh optimization algorithm to vary resolution and allow long, thin elements to align with features such as boundary layers. The modelling framework presented is quite different from the majority of ocean models in use today, which are typically based on static‐structured grids. Finite element (and volume) methods on unstructured meshes are, however, gaining popularity in the oceanographic community. The model presented here is novel in its use of unstructured meshes and anisotropic adaptivity in 3D, its ability to represent a range of coupled multi‐scale solution structures and to simulate non‐hydrostatic dynamics. Copyright © 2007 John Wiley & Sons, Ltd.
Development and usability testing of an operating manual for a hair‐braiding machine
Authors: You Heecheon , Young Ronda , Lee Myun W.
Published: December 2007

The present study applied the concepts and techniques of usability testing to the development of an operating manual for a hair‐braiding machine. A preliminary version of the manual was developed in four stages: (1) profiling user characteristics, (2) defining design features of the manual, (3) preparing contents, and (4) designing the format and layout of the manual. In each development stage, design factors, such as user characteristics and operating instructions, were identified and relevant methods, such as user profile analysis and hierarchical task analysis, were applied. The preliminary manual was evaluated by 5 cosmetology students (age, 18 to 25 years; training, 60 to 700 hours) by using various performance and preference measures and surveying opinions of the participants regarding likes, dislikes, and suggestions. Based on the test results, recommendations were made for better usability of the manual and revisions were made accordingly. The design and evaluation process of an operating manual presented in the study would help practitioners to develop a user‐friendly manual. © 2007 Wiley Periodicals, Inc.
Evaluation of a job‐aiding tool in inspection systems
Authors: Tetteh Edem , Jiang Xiaochun , Mountjoy Daniel , Seong Younho , McBride Maranda
Published: December 2007

Visual inspection plays a very important role in ensuring quality in the manufacturing and service industries. Two determinants of inspection performance are visual search and decision‐making. Improvement in any one of the components will have an impact on system performance. Job‐aids, accompanied by training, have proven to be effective in enhancing accuracy and reducing search time in visual inspection systems. This article aims to investigate the effects of search strategy along with task complexity and pacing on inspection performance using a job‐aiding tool. To facilitate the experiments, an enhanced job‐aiding tool in a simulated visual inspection environment was developed. This tool enables an inspector to track his or her search path in visual inspection systems. A pilot study and two experiments were conducted using this tool. The pilot study examined the effectiveness of the job‐aiding tool. The first experiment studied the effect of search strategy and task complexity on inspection system performance and the second experiment studied the impact of search strategy, task complexity, and pacing on system performance. Results from this research can be used to better design an inspection system. © 2007 Wiley Periodicals, Inc.
Matrix metalloproteinases 2 and 9 in central nervous system and their modification after vanadium inhalation
Authors: Colín‐Barenque L. , Martínez‐Hernández M. G. , Baiza‐Gutman L. A. , Avila‐Costa M. R. , Ordóñez‐Librado J. L. , Bizarro‐Nevares P. , Rodriguez‐Lara V. , Piñón‐Zarate G. , Rojas‐Lemus M. , Mussali‐Galante P. , Fortoul T. I.
Published: December 2007

Vanadium (V) derivatives are well‐known environmental pollutants and its toxicity has been related with oxidative stress. Toxicity after vanadium inhalation on the substantia nigra, corpus striatum, hippocampus and ependymal epithelium was reported previously. The purpose of this study was to analyse the role of matrix metalloproteinases 2 (MMP‐2) and 9 (MMP‐9) in the changes observed in brain tissue after chronic V inhalation. Mice were exposed to vaporized, vanadium pentoxide 0.02 m in deionized water for 1 h twice a week, and killed at 1 h, 1, 2 and 4 weeks after exposure. The brain was removed and the olfactory bulb, prefrontal cortex, striatum and hippocampus were dissected and the MMP content was obtained by zymography. The results showed that MMP‐9 increased in all the structures at the end of the exposure, although in the hippocampus this increment was evident after 1 week of exposure. When MMP‐2 was analysed in the olfactory bulb and prefrontal cortex it remained unchanged throughout the whole exposure, while in the hippocampus it increased at week 4, while in the striatum MMP‐2 increased from the second week only, through the whole experiment. These results demonstrate that V increased MMPs in different structures of the CNS and this change might be associated with the previously reported modifications, such as dendritic spine loss and neuronal cell death. The modifications in MMPs could be related with blood–brain barrier (BBB) disruption which was reported previously. Oxidative stress might also be involved in the activation of these gelatinases as part of the different mechanisms which take place in V toxicity in the CNS. Copyright © 2007 John Wiley & Sons, Ltd.
The USNS MERCY's Southeast Asia Humanitarian Cruise: The Perioperative Experience
Authors: Troup Linda
Published: December 2007

MANY PEOPLE IN SOUTHEAST ASIA are in desperate need of medical attention, but because of poverty, remoteness, and inadequate medical services, they do not receive this care.

BEGINNING IN APRIL 2006, a diverse group of health care professionals from around the world served for five months aboard the USNS MERCY, a 1,000‐bed, US Navy hospital ship.

DESCRIPTIONS OF PROCEDURES performed, local health conditions, and the experiences of volunteers during this humanitarian mission are detailed in this article. AORN J 86 (November 2007) 781–790.
Nuclear receptors: Decoding metabolic disease
Authors: Sonoda Junichiro , Pei Liming , Evans Ronald M.
Published: December 2007

Nuclear receptors (NR) are a superfamily of ligand‐activated transcription factors that regulate development, reproduction, and metabolism of lipids, drugs and energy. The importance of this family of proteins in metabolic disease is exemplified by NR ligands used in the clinic or under exploratory development for the treatment of diabetes mellitus, dyslipidemia, hypercholesterolemia, or other metabolic abnormalities. Genetic studies in humans and rodents support the notion that NRs control a wide variety of metabolic processes by regulating the expression of genes encoding key enzymes, transporters and other proteins involved in metabolic homeostasis. Current knowledge of complex NR metabolic networks is summarized here.
Dissection of the functional interaction between p53 and the embryonic proto‐oncoprotein PAX3
Authors: Underwood Timothy J. , Amin Jay , Lillycrop Karen A. , Blaydes Jeremy P.
Published: December 2007

Studies from murine embryogenesis and cancer cells derived from human melanomas have identified a critical role for the transcription factor PAX3 in the suppression of p53 protein accumulation and p53‐dependent apoptosis. Here we show, using a well‐defined over‐expression system, that PAX3 suppresses p53‐dependent transcription from promoters of p53‐responsive genes, notably BAX and HDM2‐P2, and reduces p53 protein abundance by promoting its degradation. We define the functional domains of PAX3 required for this activity, and furthermore present evidence that PAX3‐dependent inhibition of p53 is independent of binding of the N‐terminal domain of p53 to HDM2, the primary negative regulator of cellular p53 activity.
In
Ga
N
∕
Ga
N
light emitting diodes on nanoscale silicon on insulator
Authors: Tripathy S. , Lin V. K. X. , Teo S. L. , Dadgar A. , Diez A. , Bläsing J. , Krost A.
Published: December 2007

The authors report on the fabrication of InGaN∕GaN-based light emitting diodes (LEDs) on nanoscale silicon-on-insulator (SOI) substrates. The LED structures are grown on (111)-oriented 45nm thick SOI overlayer by metal organic chemical vapor deposition. Square-shaped mesa patterns are created by standard LED processing steps including multiple-mask photolithography, inductive coupled plasma etching, and contact metallization. Due to the high reflective Si∕SiO2 beneath AlN buffer and high refractive contrasts at the interfaces, the authors observed multiple interference peaks from LEDs on SOI and such effect resulted in an increased integrated electroluminescence intensity when compared to LED structures fabricated on bulk Si(111).
Metallic conductivity at the CaHfO3∕SrTiO3 interface
Authors: Shibuya Keisuke , Ohnishi Tsuyoshi , Lippmaa Mikk , Oshima Masaharu
Published: December 2007

The transport and photoluminescence properties of interfaces between amorphous CaHfO3 films and SrTiO3 single crystal substrates were investigated. Although both materials are band-gap insulators, the interfaces were metallic. The sheet carrier density was found to depend strongly on the laser fluence used during the CaHfO3 layer fabrication by pulsed laser deposition, indicating the presence of oxygen vacancies at the interface. The Hall mobility of the heterostructures saturated at 2000cm2∕Vs at low temperature. Photoluminescence spectra showed an oxygen vacancy-related emission band at around 420nm.
Characterization of ZnO:N films prepared by annealing sputtered zinc oxynitride films at different temperatures
Authors: Zhang J. P. , Zhang L. D. , Zhu L. Q. , Zhang Y. , Liu M. , Wang X. J. , He G.
Published: December 2007

N-doped ZnO films were prepared by annealing zinc oxynitride films deposited by rf reactive sputtering. Two Raman peaks were observed at 274 and 580 cm−1. According to the variation of the integral intensity of these two peaks, the nitrogen activation at 500 °C [the activation temperature (AT)] has been obtained. Below the AT, the integral intensities of them show a different variation trend. X-ray photoelectron spectroscopy (XPS) indicates the N chemical state variation for them and finds the activated Zn-N bond. Further analyses by photoluminescence (PL) spectra and spectroscopic ellipsometry (SE) have been carried out. The activated sample exhibits a symmetric emission peak at 3.22 eV assigned to be the AX0 emission at room temperature. SE investigation takes account of samples within the different temperature span divided by the AT. Different factors, such as nitrogen dopant (N)O and the nanocrystal growth, which affect the redshift of the absorption edges, have been discussed.
Low-loss quantum-dot-based saturable absorber for efficient femtosecond pulse generation
Authors: Lagatsky A. A. , Bain F. M. , Brown C. T. A. , Sibbett W. , Livshits D. A. , Erbert G. , Rafailov E. U.
Published: December 2007

We report the efficient generation of femtosecond pulses from a diode-pumped solid-state laser that has been passively mode locked using a quantum-dot-based saturable absorber. Average output powers up to 1.15W and transform-limited pulses as short as 114fs were obtained around 1040nm with a pulse repetition frequency of 107MHz from a diode-pumped Yb3+:KY(WO4)2 laser. The InGaAs quantum-dot saturable absorber was characterized to have a saturation fluence of 25μJ∕cm2 and nonsaturable losses of less than 0.2% with an initial low-signal absorption of 2.5% at 1040nm.
Fabrication and characterization of tin-based nanocrystals
Authors: Huang Shujuan , Cho Eun-Chel , Conibeer Gavin , Green Martin A. , Bellet Daniel , Bellet-Amalric Edith , Cheng Shuying
Published: December 2007

Sn-based nanocrystals were prepared by depositing Sn-rich SiO2 films using a cosputtering process and a subsequent vacuum annealing. Transmission electron microscopy (TEM) and x-ray diffraction showed formation of Sn nanocrystals evenly distributed in SiO2 matrix at relatively low annealing temperature of 400°C. The size of Sn nanocrystals increased with increasing annealing temperature. X-ray photoelectron spectroscopy revealed that Sn was partially oxidized during the cosputtering process forming Sn oxide nanoclusters of 3.4±0.6nm in diameter after annealing, as observed by TEM. The Sn-based nanocrystal films exhibited wide optical bandgap around 4.2–4.4eV and a slightly high-energy shift with increasing annealing temperature. This result is in close agreement with the absorption in the Sn oxide nanoclusters as well as Sn-related oxygen defects in the matrix.
Relieved kink effects in symmetrically graded In0.45Al0.55As∕InxGa1−xAs metamorphic high-electron-mobility transistors
Authors: Lee Ching-Sung , Liao Chen-Hsian
Published: December 2007

Kink effects in an In-rich InxGa1−xAs (x=0.53–0.63) linearly graded channel of an In0.45Al0.55As∕InxGa1−xAs metamorphic high-electron-mobility transistor have been effectively relieved by depositing a high-barrier Ni∕Au gate with the silicon nitride passivation. Complete physical investigations for the relieved kink effects have been made by comparing identical devices with/without a high-barrier Schottky gate or the surface passivation. After successfully suppressing the kink effects, the proposed device has shown a superior voltage gain of 173.8, low output conductance of 2.09mS∕mm, and excellent power-added efficiency of 54.1% with high output power (power gain) of 14.87dBm (14.53dB). Improved linearity and excellent thermal threshold coefficient (∂Vth∕∂T) of −0.14mV∕K have also been achieved. The proposed design provides good potential for high-gain and high-linearity circuit applications.
Depth sensitive exchange coupled spin structure in NiFe∕FeMn bilayer
Authors: Kim CheolGi , Seo J. H. , Parvatheeswara Rao B.
Published: December 2007

Magnetization mechanisms in NiFe and NiFe∕FeMn layered systems have been studied using vibration sample magnetometry (VSM) and transverse Kerr effect spectrometry (TKE). The TKE signal was examined at the wavelengths of 300, 500, and 700nm and at various fields from 12to85Oe at each wavelength by aiming at a depth sensitive exchange coupled magnetic profile in the probed ferromagnetic layer. An attempt has been made to correlate the features from the M-H curve profiles measured using VSM under dc magnetic field and TKE with ac magnetic field to the exchange coupled spin structures. The results point toward a short range order of biquadratic exchange coupling near the interface. Based on the data and analysis, possible spin structures were proposed and depth profiles of decomposed magnetization due to biquadratic and bilinear exchange couplings were reported.
Enhanced field emission from CuO nanowire arrays by in situ laser irradiation
Authors: Zhu Y. W. , Sow C. H. , Thong J. T. L.
Published: December 2007

Laser irradiation was found to effectively enhance the field emission current of CuO nanowire arrays. The effects of laser intensity, wavelength, emission current, and working vacuum on the enhancement have been investigated in detail. The observed laser induced enhancement in field emission current is attributed to the interplay of two factors, namely, laser induced electron transition to excited states and surface oxygen desorption. Among these factors, the contribution from extra excited electrons, which increases the number of electrons in conduction band of CuO for subsequent tunneling, is dominant. A physical process of the laser induced enhancement is discussed. This work helps to elucidate the mechanisms of electron field emission from narrow band gap nanowires and will be useful for designing future vacuum nanodevices, such as photodetectors or switches, based on field emission of nanowires.
Pressure and temperature tuning of the valence band offset in cubic superlattices: The effects of piezoelectric fields
Authors: Wen T. D. , Xu L. P. , Xiong J. J. , Zhang W. D. , Wu Mingzhong , Hochheimer H. D.
Published: December 2007

Theoretical calculations have been performed to study the effects of piezoelectric fields in superlattice systems. The results show that cubic strained superlattices and quantum wells subjected to variable temperature and pressure exhibit changes in their piezoelectric fields. We consider superlattice systems grown in arbitrary directions, with a thickness smaller and larger than the critical thickness value (undercritical and overcritical systems). In both cases (including the partially relaxed case), theory predicts the existence of a critical temperature Tm and a critical pressure pm, above which the sign of the piezoelectric fields in each layer reverses. As applications to practical systems, we calculated (1) the piezoelectric fields as a function of temperature in GaAs∕ZnSe superlattice and (2) the piezoelectric fields as a function of pressure in GaAs∕InAs, GaAs∕Si, and ZnSe∕GaAs superlattice systems. We present here the results of the effects of piezoelectric fields for three different systems (undercritical systems, overcritical systems, and partially relaxed systems), where the piezoelectric field changes under variable temperature, pressure, and thickness of the layers. We also discuss the valence band offset, which is induced by piezoelectric fields, and its dependence on temperature and pressure. In addition, we present data on the valence band offset for some practical undercritical systems. All results and conclusions are valid in a linear region of strain or stress where no phase transitions occur.
Multiplicativity of the maximal output 2-norm for depolarized Werner-Holevo channels
Authors: Michalakis S.
Published: December 2007

We study the multiplicativity of the output 2-norm for depolarized Werner-Holevo channels and show that multiplicativity holds for a product of two identical channels in this class. Moreover, it is shown that the depolarized Werner-Holevo channels do not satisfy the entrywise positivity condition introduced by King and Ruskai (e-print quant-ph∕0909181v2; e-print quant-ph∕0981026v1), which suggests that the main result is nontrivial.
Effect of nitrogen addition on the band gap, core level shift, surface energy, and the threshold field of electron emission of the SrTiO3 thin films
Authors: Bian H. J. , Chen X. F. , Pan J. S. , Zhu W. , Sun Chang Q.
Published: December 2007

The effect of nitrogen (N) doping on the behavior of field emission, surface energy and the band structure of strontium titanate (SrTiO3) thin films coated on silicon tip arrays has been examined in detail. Measurements using x-ray photoelectron spectroscopy, ellipsometry, water contact angle and field emission testing revealed that the optimal 50%-nitrogen partial pressure (PN) could improve substantially the threshold field of electron emission of the SrTiO3 films accompanied with narrowed band gap, lowered surface energy and work function and a negative energy shift of the N 1s level from 404 to 396 eV. Results evidence consistently the presence of the nonbonding lone pairs and the lone pair induced antibonding dipoles upon tetrahedron formation which is responsible for the observations. At PN below and above the optimal value physisorption and hydrogen bond likes formation like to occur.
Substrate removal for high quantum efficiency back side illuminated type-II InAs∕GaSb photodetectors
Authors: Delaunay Pierre-Yves , Nguyen Binh Minh , Hofman Darin , Razeghi Manijeh
Published: December 2007

A substrate removal technique using an InAsSb etch stop layer improves by a factor of 2 the quantum efficiency of back side illuminated type-II InAs∕GaSb superlattice photodetectors. After etching of the GaSb substrate with a CrO3 based solution, the quantum efficiency of the diodes presents Fabry-Pérot oscillations averaging at 56%. Due to the confinement of the infrared light inside the devices, the quantum efficiency for certain devices reaches 75% at 8.5μm. The implementation of this new technique to a focal plane array resulted in a decrease of the integration time from 0.23to0.08ms.
Pictures in Mind: Initial Encoding of Object Properties Varies with the Realism of the Scene Stimulus
Authors: Tatler Benjamin W , Melcher David
Published: December 2007

A fundamental question in perception is how we visually encode and retain information about a complex scene in order to allow effective operation within it. Interestingly, the stimuli used to investigate scene perception have varied greatly between studies, ranging from line drawings to coloured drawings, computer-generated scenes, photographs, and real scenes. Are findings from these different types of scene stimulus equally ecologically valid? Two experiments are reported that address this issue. In the first we compared photographic and non-photographic scenes and found that observers perform better in questions testing object memory when viewing photographs, suggesting an initial benefit for encoding information from photographs. In the second we found that whether or not non-photographic scenes obeyed realistic scene-organising properties influenced object-memory formation. Effects varied for the different question types, but again were most prominent early in viewing. We conclude that in the search for an understanding of everyday scene perception we must be very careful in our choice of scene stimuli and in our interpretation of findings from the laboratory.
Monomeric myosin V uses two binding regions for the assembly of stable translocation complexes
Authors: Heuck Alexander , Du Tung-Gia , Jellbauer Stephan , Richter Klaus , Kruse Claudia , Jaklin Sigrun , Müller Marisa , Buchner Johannes , Jansen Ralf-Peter , Niessing Dierk
Published: December 2007

Myosin-motors are conserved from yeast to human and transport a great variety of cargoes. Most plus-end directed myosins, which constitute the vast majority of all myosin motors, form stable dimers and interact constitutively with their cargo complexes. To date, little is known about regulatory mechanisms for cargo-complex assembly. In this study, we show that the type V myosin Myo4p binds to its cargo via two distinct binding regions, the C-terminal tail and a coiled-coil domain-containing fragment. Furthermore, we find that Myo4p is strictly monomeric at physiologic concentrations. Because type V myosins are thought to require dimerization for processive movement, a mechanism must be in place to ensure that oligomeric Myo4p is incorporated into cargo-translocation complexes. Indeed, we find that artificial dimerization of the Myo4p C-terminal tail promotes stabilization of myosin-cargo complexes, suggesting that full-length Myo4p dimerizes in the cocomplex as well. We also combined the Myo4p C-terminal tail with the coiled-coil region, lever arm, and motor domain from a different myosin to form constitutively dimeric motor proteins. This heterologous motor successfully translocates its cargo
in vivo
, suggesting that wild-type Myo4p may also function as a dimer during cargo-complex transport.
Prospective, Controlled, Cross-Over Trial of Alcohol-Based Hand Gel in Critical Care Units
Authors: Rupp Mark E. , Fitzgerald Teresa , Puumala Susan , Anderson James R. , Craig Rita , Iwen Peter C. , Jourdan Dawn , Keuchel Janet , Marion Nedra , Peterson Delayne , Sholtz Lee , Smith Valerie
Published: December 2007

Background.

There are limited data from prospective studies to indicate whether improvement in hand hygiene associated with the use of alcohol-based hand hygiene products results in improved patient outcomes.

Design.

A 2-year, prospective, controlled, cross-over trial of alcohol-based hand gel.

Setting.

The study was conducted in 2 medical-surgical ICUs for adults, each with 12 beds, from August 2001 to September 2003 at a university-associated, tertiary care teaching hospital.

Methods.

An alcohol-based hand gel was provided in one critical care unit and not provided in the other. After 1 year, the assignment was reversed. The hand hygiene adherence rate and the incidence of nosocomial infection were monitored. Samples for culture were obtained from nurses' hands every 2 months.

Results.

During 17,994 minutes of observation, which included 3,678 opportunities for hand hygiene, adherence rates improved dramatically after the introduction of hand gel, increasing from 37% to 68% in one unit and from 38% to 69% in the other unit (P< .001). Improvement was observed among all groups of healthcare workers. Hand hygiene rates were better at higher workloads when hand gel was available in the unit (P= .02). No substantial change in the rates of device-associated infection, infection due to multidrug-resistant pathogens, or infection due toClostridium difficilewas observed. Culture of samples from the hands of nursing staff revealed that an increased number of microbes and an increased number of microbe species was associated with longer fingernails (ie, more than 2 mm long), the wearing of rings, and/or lack of access to hand gel.

Conclusions.

The introduction of alcohol-based gel resulted in a significant and sustained improvement in the rate of hand hygiene adherence. Fingernail length greater than 2 mm, wearing rings, and lack of access to hand gel were associated with increased microbial carriage on the hands. This improvement in the hand hygiene adherence rate was not associated with detectable changes in the incidence of healthcare-associated infection.
Maize 9-Lipoxygenase ZmLOX3 Controls Development, Root-Specific Expression of Defense Genes, and Resistance to Root-Knot Nematodes
Authors: Gao Xiquan , Starr James , Göbel Cornelia , Engelberth Jürgen , Feussner Ivo , Tumlinson James , Kolomiets Michael
Published: December 2007

Root-knot nematodes (RKN) are severe pests of maize. Although lipoxygenase (LOX) pathways and their oxylipin products have been implicated in plant–nematode interactions, prior to this report there was no conclusive genetic evidence for the function of any plant LOX gene in such interactions. We showed that expression of a maize 9-LOX gene, ZmLOX3, increased steadily and peaked at 7 days after inoculation with Meloidogyne incognita RKN. Mu-insertional lox3-4 mutants displayed increased attractiveness to RKN and an increased number of juveniles and eggs. A set of jasmonic acid (JA)- and ethylene (ET)-responsive and biosynthetic genes as well as salicylic acid (SA)-dependent genes were overexpressed specifically in the roots of lox3-4 mutants. Consistent with this, levels of JA, SA, and ET were elevated in lox3-4 mutant roots, but not in leaves. Unlike wild types, in lox3-4 mutant roots, a phenylalanine ammonia lyase (PAL) gene was not RKN-inducible, suggesting a role for PAL-mediated metabolism in nematode resistance. In addition to these alterations in the defense status of roots, lox3-4 knockout mutants displayed precocious senescence and reduced root length and plant height compared with the wild type, suggesting that ZmLOX3 is required for normal plant development. Taken together, our data indicate that the ZmLOX3-mediated pathway may act as a root-specific suppressor of all three major defense signaling pathways to channel plant energy into growth processes, but is required for normal levels of resistance against nematodes.
Transparency in the Foreign Exchange Market and the Volume of International Trade
Authors: Broll Udo , Eckwert Bernhard
Published: December 2007

In this paper we study the impact of more transparency in the foreign exchange market on the ex ante expected volume of international trade. Transparency is measured by the informational content of publicly observable signals. These signals convey information about the use of policy instruments which affect the future exchange rate. We find that a higher level of transparency may increase or decrease the volume of international trade. In particular, the impact of greater transparency depends on the curvature of the firms’ marginal cost function. Furthermore, the firms’ex ante expected profits are higher when the foreign exchange market is more transparent.