bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toll‐like receptor 4 Asp299Gly polymorphism in respiratory syncytial virus epidemics
Authors: Löfgren Johan , Marttila Riitta , Renko Marjo , Rämet Mika , Hallman Mikko 
Published: May 2010

AbstractThe respiratory syncytial virus (RSV) antigen serves as ligand for Toll‐like receptor (TLR) 4 that is a transmembrane signaling receptor in macrophages and dendritic cells. According to current evidence single nucleotide polymorphism involving amino acid 299 influences the susceptibility to severe RSV infections. The Asp299Gly allele has been shown to influence the TLR4‐mediated signaling causing conformational change in the extracellular domain that recognizes pathogen‐associated molecular patterns. The aim was to study the association between the TLR4 Asp299Gly polymorphism and the susceptibility to severe RSV bronchiolitis in infants. Altogether 312 cases and 356 controls, selected on the basis place of residence, date of birth, gender, and gestation at birth, were studied. When adjusted for multiple dependent variables, no allele or genotype frequency difference was found between the cases and the controls. Post hoc analysis revealed that during the year 2000 epidemics, the Gly299Gly genotype associated with protection against severe RSV and during 2004 epidemics Gly299Gly genotype and 299Gly allele associated with severe RSV. To conclude, we could not confirm the association of the Gly299 allele with severe RSV. This is consistent with the evidence that the susceptibility to severe RSV infection is principally dependent on environmental and constitutional factors. We propose that the risk of severe RSV infection may additionally depend on the interaction between individual TLR4 genotype and the particular RSV group causing bronchiolitis. Pediatr Pulmonol. 2010; 45:687–692. © 2010 Wiley‐Liss, Inc.
Tracheal gas insufflation with partial liquid ventilation to treat LPS‐induced acute lung injury in juvenile piglets
Authors: Guo Zhong‐Liang , Liang Yong‐Jie , Lu Guo‐Ping , Wang Jun‐Chen , Ren Tao , Zheng Yong‐Hua , Gong Jing‐Yu , Yu Jerry 
Published: May 2010

AbstractObjectivesPartial liquid ventilation (PLV) with perfluorocarbons (PFC) seems not superior to conventional ventilation clinically. We hypothesized that a combination of continuous tracheal gas insufflation (TGI) with protective strategy of PLV (low dose of PFC, low inflation pressure, moderate inhalation of oxygen and moderate anesthesia) would improve cardiopulmonary function in acute lung injury.MethodsTwenty‐four healthy juvenile piglets were anesthetized and mechanically ventilated at PEEP of 2 cmH2O with a peak inspiratory pressure of 10 cmH2O and FIO2 of 0.4. The piglets were challenged with lipopolysaccharide and randomly assigned to four groups (n = 6 each): (1) mechanical ventilation alone (MV); (2) PLV with perfluorodecalin (10 ml/kg); (3) TGI with continuous airway flow 2 L/min; and (4) combination of PLV and TGI. The outcome was assessed functionally and histologically.ResultsAll treatments except MV improved pH, PaO2/FIO2, PaCO2, ventilation efficacy index (VEI) and tidal volume. Both PLV‐associated treatments also improved heart rate, respiratory rate, pulse contour cardiac output, systemic vascular resistance, dynamic lung compliance, mean airway resistance and mean airway pressure. The combination group resulted in higher PaO2/FIO2, VEI and a better lung histology score than any other treatments.ConclusionsThe new protective strategy may provide a better treatment for sepsis‐induced acute lung injury. Pediatr Pulmonol. 2010; 45:700–707. © 2010 Wiley‐Liss, Inc.
Phosphorus‐Based Nanothermites: A New Generation of Pyrotechnics Illustrated by the Example of n‐CuO/Red P Mixtures
Authors: Comet Marc , Siegert Benny , Schnell Fabien , Pichot Vincent , Ciszek Fabrice , Spitzer Denis 
Published: May 2010

AbstractThe use of aluminium nanoparticles (e.g. Al 50P) with various metallic oxides to prepare superthermites was reported in numerous recent papers. These compositions have exceptional energetic performances, but their fabrication cannot be scaled up due to the difficulty in producing or supplying aluminium nanopowders. The use of red phosphorus as an alternative reducing agent in nanothermite compositions was found to be very promising. Surprisingly, although this substance is a component of many explosive compositions, it was never tested with metallic oxide nanoparticles. In a preliminarily study, the reactivity of different metallic oxides with red phosphorus was screened. These tests led to classify the oxides according to their combustion potential, by ascending order: NiO<Fe2O3 $\rm{ \ll }$ CuO $\rm{ \ll }$ PbO2. The CuO/P mixture possesses an impressive reactivity, and its combustion residues are less hazardous than those formed with PbO2 insofar as lead derivatives are generally more toxic than their copper counterparts. CuO‐based P‐nanothermites were prepared by physically mixing copper(II) oxide nanoparticles with micrometre‐sized red phosphorus particles. The phosphorus content was varied from 16 to 50 wt.‐% in order to investigate the effect of the mass ratio on the reactivity of CuO/P materials. The impact sensitivity of CuO/P nanothermites is moderate (27–39 J), but their friction (<5–8 J) and electrostatic discharge sensitivities (<0.12–0.21 mJ) are extremely high. The combustion of P‐nanothermites (P‐NT) gives droplets of molten copper with a typical fractal structure after cooling down.
Linear Actuation Using Milligram Quantities of CL‐20 and TAGDNAT
Authors: Tappan Alexander S. , Basiliere Marc , Ball J. Patrick , Snedigar Shane , Fischer Gary J. , Salton Jonathan 
Published: May 2010

AbstractThere are numerous applications for small‐scale actuation utilizing pyrotechnics and explosives. In certain applications, especially when multiple actuation strokes are needed, or actuator reuse is required, it is desirable to have all gaseous combustion products with no condensed residue in the actuator cylinder. Toward this goal, we have performed experiments on utilizing milligram quantities of high explosives to drive a millimeter‐diameter actuator with a stroke of 30 mm. Calculations were performed to select proper material quantities to provide 0.5 J of actuation energy. This was performed utilizing the thermochemical code Cheetah to calculate the impetus for numerous propellants and to select quantities based on estimated efficiencies of these propellants at small scales. Milligram quantities of propellants were loaded into a small‐scale actuator and ignited with an ignition increment and hot wire ignition. Actuator combustion chamber pressure was monitored with a pressure transducer and actuator stroke was monitored using a laser displacement meter. Total actuation energy was determined by calculating the kinetic energy of reaction mass motion against gravity. Of the materials utilized, the best performance was obtained with a mixture of 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20) and bis‐triaminoguanidinium(3,3′dinitroazotriazolate) (TAGDNAT).
Telerehabilitation mediated physiotherapy assessment of ankle disorders
Authors: Russell Trevor G. , Blumke Robert , Richardson Bradley , Truter Piers 
Published: May 2010

AbstractBackground and Purpose. Musculoskeletal injuries are the most common source of chronic pain and disability. The ankle joint is the most common of these injuries and without adequate rehabilitation function can be severely impaired. Access to physiotherapy rehabilitation services can be limited due to geographical remoteness and a shortage of services in rural and remote areas. Telerehabilitation is a potential solution to bridge this service delivery gap. The aim of this study was to determine the criterion validity and reliability of conducting a remote musculoskeletal assessment of the ankle joint complex using telerehabilitation technologies compared with a face‐to‐face assessment. Methods. This study utilized a repeated measures design to assess 15 subjects (mean age 24.5, SD 10.8 years) presenting with ankle pain. Conventional face‐to‐face assessments were compared with assessments performed via a telerehabilitation system. Results. A similar agreement of 93.3% in patho‐anatomical diagnosis and an 80% exact agreement (χ2 = 4.267; p < 0.04) in primary systems diagnosis was found between face‐to‐face and telerehabilitation assessments. Clinical observations were found to have very strong agreement (k = 0.92) for categorical data and significant agreement (93.3% agreement; χ2 = 234.4; p < 0.001) for binary data. A high level of inter‐ and intrarater reliability was found for the telerehabilitation assessments. Conclusions. This study demonstrates the criterion validity and reliability of remote musculoskeletal assessments of the ankle joint complex using telerehabilitation. Copyright © 2010 John Wiley & Sons, Ltd.
Functional dissection of an intrinsically disordered protein: Understanding the roles of different domains of Knr4 protein in protein–protein interactions
Authors: Dagkessamanskaia Adilia , Durand Fabien , Uversky Vladimir N. , Binda Matteo , Lopez Frédéric , El Azzouzi Karim , Francois Jean Marie , Martin‐Yken Hélène 
Published: May 2010

AbstractKnr4, recently characterized as an intrinsically disordered Saccharomyces cerevisiae protein, participates in cell wall formation and cell cycle regulation. It is constituted of a functional central globular core flanked by a poorly structured N‐terminal and large natively unfolded C‐terminal domains. Up to now, about 30 different proteins have been reported to physically interact with Knr4. Here, we used an in vivo two‐hybrid system approach and an in vitro surface plasmon resonance (BIAcore) technique to compare the interaction level of different Knr4 deletion variants with given protein partners. We demonstrate the indispensability of the N‐terminal domain of Knr4 for the interactions. On the other hand, presence of the unstructured C‐terminal domain has a negative effect on the interaction strength. In protein interactions networks, the most highly connected proteins or “hubs” are significantly enriched in unstructured regions, and among them the transient hub proteins contain the largest and most highly flexible regions. The results presented here of our analysis of Knr4 protein suggest that these large disordered regions are not always involved in promoting the protein–protein interactions of hub proteins, but in some cases, might rather inhibit them. We propose that this type of regions could prevent unspecific protein interactions, or ensure the correct timing of occurrence of transient interactions, which may be of crucial importance for different signaling and regulation processes.
DE‐loop mutations affect β2 microglobulin stability, oligomerization, and the low‐pH unfolded form
Authors: Santambrogio Carlo , Ricagno Stefano , Colombo Matteo , Barbiroli Alberto , Bonomi Francesco , Bellotti Vittorio , Bolognesi Martino , Grandori Rita 
Published: May 2010

Abstractβ2 microglobulin (β2m) is the light chain of class‐I major histocompatibility complex (MHC‐I). Its accumulation in the blood of patients affected by kidney failure leads to amyloid deposition around skeletal joints and bones, a severe condition known as Dialysis Related Amyloidosis (DRA). In an effort to dissect the structural determinants of β2m aggregation, several β2m mutants have been previously studied. Among these, three single‐residue mutations in the loop connecting strands D and E (W60G, W60V, D59P) have been shown to affect β2m amyloidogenic properties, and are here considered. To investigate the biochemical and biophysical properties of wild‐type (w.t.) β2m and the three mutants, we explored thermal unfolding by Trp fluorescence and circular dichroism (CD). The W60G mutant reveals a pronounced increase in conformational stability. Protein oligomerization and reduction kinetics were investigated by electrospray‐ionization mass spectrometry (ESI‐MS). All the mutations analyzed here reduce the protein propensity to form soluble oligomers, suggesting a role for the DE‐loop in intermolecular interactions. A partially folded intermediate, which may be involved in protein aggregation induced by acids, accumulates for all the tested proteins at pH 2.5 under oxidizing conditions. Moreover, the kinetics of disulfide reduction reveals specific differences among the tested mutants. Thus, β2m DE‐loop mutations display long‐range effects, affecting stability and structural properties of the native protein and its low‐pH intermediate. The evidence presented here hints to a crucial role played by the DE‐loop in determining the overall properties of native and partially folded β2m.
The transcription repressor NmrA is subject to proteolysis by three Aspergillus nidulans proteases
Authors: Zhao Xiao , Hume Samantha L. , Johnson Christopher , Thompson Paul , Huang Junyong , Gray Joe , Lamb Heather K. , Hawkins Alastair R. 
Published: May 2010

AbstractThe role of specific cleavage of transcription repressor proteins by proteases and how this may be related to the emerging theme of dinucleotides as cellular signaling molecules is poorly characterized. The transcription repressor NmrA of Aspergillus nidulans discriminates between oxidized and reduced dinucleotides, however, dinucleotide binding has no effect on its interaction with the zinc finger in the transcription activator AreA. Protease activity in A. nidulans was assayed using NmrA as the substrate, and was absent in mycelium grown under nitrogen sufficient conditions but abundant in mycelium starved of nitrogen. One of the proteases was purified and identified as the protein Q5BAR4 encoded by the gene AN2366.2. Fluorescence confocal microscopy showed that the nuclear levels of NmrA were reduced approximately 38% when mycelium was grown on nitrate compared to ammonium and absent when starved of nitrogen. Proteolysis of NmrA occurred in an ordered manner by preferential digestion within a C‐terminal surface exposed loop and subsequent digestion at other sites. NmrA digested at the C‐terminal site was unable to bind to the AreA zinc finger. These data reveal a potential new layer of control of nitrogen metabolite repression by the ordered proteolytic cleavage of NmrA. NmrA digested at the C‐terminal site retained the ability to bind NAD+ and showed a resistance to further digestion that was enhanced by the presence of NAD+. This is the first time that an effect of dinucleotide binding to NmrA has been demonstrated.
Extremal black holes, attractor equations, and harmonic functions
Authors: Mohaupt T. , Waite K. 
Published: May 2010

AbstractWe review the construction of multi‐centered black hole solutions through dimensional reduction over time. This method does not rely on Killing spinor equations or gradient flow equations, but on solving the second order field equations in terms of harmonic functions. The black hole attractor equations are obtained directly from the field equations.
The μ‐problem, the NMSSM and string theory
Authors: Ramos‐Sánchez S. 
Published: May 2010

AbstractWe discuss recent developments on the solution of the so‐called supersymmetric μ‐problem in the context of heterotic orbifolds. In particular, an approximate R symmetry can induce an admissible μ‐term in Minkowski vacua of orbifold models with the MSSM spectrum. A natural solution to the μ‐problem is offered by explicitly string derived NMSSMs. These models also ameliorate the fine‐tuning of the MSSM.
Geometric flows and applications
Authors: Petropoulos P.M. 
Published: May 2010

AbstractI present some applications of geometric flows in string theory and gravity. In some circumstances time evolution in string theory can be approximately identified with Ricci‐flow parametric evolution of spatial sections. In four dimensions, homogeneous, self‐dual, gravitational instantons of general relativity evolve in time exactly as geometric flows of homogeneous three‐manifolds. For non‐relativistic versions of gravity, this property persists in any dimension, under the assumption of detailed‐balance condition.
Facet formation for laser diodes on nonpolar and semipolar GaN
Authors: Rass Jens , Wernicke Tim , Kremzow Raimund , John Wilfred , Einfeldt Sven , Vogt Patrick , Weyers Markus , Kneissl Michael 
Published: May 2010

AbstractDifferent technologies have been evaluated in order to create vertical and smooth facets for GaN‐based laser diodes on non‐ and semipolar substrates. Laser assisted scribing and cleaving proved to be a suitable method to create c‐, a‐ and m‐plane facets for devices grown on nonpolar, polar and semipolar GaN planes. The RMS roughness measured by atomic force microscopy was found to be less than 1 nm. Semipolar facets showed tilted or multifaceted cleavage planes. Dry etching using inductively coupled plasma etching (ICP) resulted in vertical facets for devices grown on polar c‐plane GaN, while the facets of semipolar $(11\overline 2 2)$ GaN on sapphire exhibited a slight tilt depending on the crystal orientation. Wet chemical postprocessing of semipolar facets can improve the tilt angle but suffers from a roughening of the facets due to selective dislocation etching. By using a focussed ion beam (FIB) it is possible to create vertical and smooth facets independent of the crystal orientation.
High‐output‐power AlGaN/GaN ultraviolet‐light‐emitting diodes by activation of Mg‐doped p‐type AlGaN in oxygen ambient
Authors: Nagata Kengo , Ichikawa Tomoki , Takeda Kenichiro , Nagamatsu Kentaro , Iwaya Motoaki , Kamiyama Satoshi , Amano Hiroshi , Akasaki Isamu 
Published: May 2010

AbstractWe demonstrated activation annealing of Mg‐doped p‐type Al0.17Ga0.83N in different gases. The hole concentration of Al0.17Ga0.83N annealed in oxygen is higher than that annealed in nitrogen or air. A hole concentration of 1.3 × 1016 cm−3 at room temperature was achieved by annealing in oxygen flow at 900 °C. Secondary ion mass spectroscopy shows that hydrogen dissociation from Mg‐doped Al0.17Ga0.83N is found to be enhanced by annealing in a flow of oxygen, compared with annealing in a flow of nitrogen. We confirmed the effect of activation annealing in oxygen flow on the performance of UV light‐emitting diode (LED). At a DC current of 100 mA, the output power of the LED annealed in oxygen flow at 900 °C is four times higher than that of the LED annealed in nitrogen flow at 800 °C.
Electroluminescence properties of Eu‐doped GaN‐based red light‐emitting diode by OMVPE
Authors: Nishikawa Atsushi , Kawasaki Takashi , Furukawa Naoki , Terai Yoshikazu , Fujiwara Yasufumi 
Published: May 2010

AbstractWe investigated the electroluminescence (EL) properties of europium (Eu)‐doped GaN‐based red light‐emitting diode (LED). Under current injection, the energy transfer from the GaN host material to Eu3+ ions successfully occurred and the red emission from Eu3+ ions was observed with naked eyes under normal lighting conditions at room temperature (RT). The operation voltage was as low as 2.4 V. The dominant peak was observed at a wavelength of 621 nm and its intensity increased with increasing applied voltage. The several peaks beside the main peak appeared with higher injected currents in the EL spectrum. The light output power, which was integrated over the main peak, as a function of injected current shows the saturated behaviour in the high injected current region. As a result, the external quantum efficiency was still lower than the conventional GaN‐based blue and green LEDs at high injected current. However, this result suggests a novel way to realize GaN‐based red LEDs, which leads to realize a monolithic device composed of red, green and blue GaN‐based LEDs for full‐colour display or lighting technology.
In‐clustering effects in InAlN and InGaN revealed by high pressure studies
Authors: Gorczyca I. , Suski T. , Kamińska A. , Staszczak G. , Schenk H. P. D. , Christensen N. E. , Svane A. 
Published: May 2010

AbstractElectronic band structure calculations of InAlN and InGaN under pressure are presented for two different arrangements of the In atoms, uniform and clustered. The band gap pressure coefficients exhibit strong bowing, and the effect is especially large when indium atoms are clustered. The theoretical results are compared with the results of photoluminescence measurements performed at high hydrostatic pressures on InAlN and InGaN quasi‐bulk epilayers. We discuss the modification of the uppermost valence band due to formation of In clusters which, together with the related lattice relaxations, may be a possible source of the observed phenomena.
Structural properties of MBE AlInN and AlGaInN barrier layers for GaN‐HEMT structures
Authors: Kirste Lutz , Lim Taek , Aidam Rolf , Müller Stefan , Waltereit Patrick , Ambacher Oliver 
Published: May 2010

AbstractA high‐resolution X‐ray diffraction and X‐ray reflectivity study of the structural properties of AlInN/GaN and AlGaInN/GaN high electron mobility transistor structures deposited by molecular beam epitaxy on metal organic chemical vapor deposition GaN/Al2O3 and GaN/SiC templates is presented. A new AlN/GaN/AlN triple‐interlayer is implemented to improve the interface properties between barrier layer and GaN buffer for a higher mobility of the polarization induced two‐dimensional electron gas. Layer properties and structural parameters like concentration, interface quality, layer thickness, strain and crystalline perfection are analyzed. Best structural properties are achieved for an AlGaInN layer with AlN/GaN/AlN interlayer deposited on a GaN/4H‐SiC (00.1) template.
Fabrication of freestanding 2″‐GaN wafers by hydride vapour phase epitaxy and self‐separation during cooldown
Authors: Lipski Frank , Wunderer Thomas , Schwaiger Stephan , Scholz Ferdinand 
Published: May 2010

AbstractUsing a dielectric mask, structured by optical lithography, freestanding 2″‐GaN wafers were prepared by hydride vapour phase epitaxy (HVPE) and self‐separation during cooldown. The mask was deposited on a GaN template grown on sapphire by metal organic vapour phase epitaxy (MOVPE) and it was shown that the instability of a SiN mask at growth temperature supports the further self‐separation. Testing different mask geometries, a hexagonally shaped pattern with a period of 30 µm and an opening of 3 µm showed best performance. This mask allowed the growth and separation of a full 2″ GaN wafer by utilizing the stress arising during cooldown from thermal mismatch to the substrate. Thickness inhomogenity was below 10% and the samples show good surface morphology.
Fabrication of blue and green non‐polar InGaN/GaN multiple quantum well light‐emitting diodes on LiAlO2(100) substrates
Authors: Liu Bin , Han Ping , Xie Zili , Zhang Rong , Liu Chengxiang , Xiu Xiangqian , Hua Xuemei , Lu Hai , Chen Peng , Zheng Youdou , Zhou Shengming 
Published: May 2010

AbstractThe non‐polar m‐plane InGaN/GaN light‐emitting diodes (LEDs) grown by metal‐organic chemical vapor deposition (MOCVD) on LiAlO2(100) substrates were investigated. The structure of LEDs is composed by GaN p–n junction and five InGaN/GaN multiple quantum wells (MQWs). They emit blue or green light, respectively, with different indium composition of InGaN as active layers in the MQWs. Third‐order satellite peaks are observed in high resolution X‐ray diffraction spectrum, indicating good quantum well interfaces. For 800 × 800 µm2 blue LED device, the output power achieves 3 mW under 200 mA injection current. The electroluminescence (EL) spectra of both non‐polar blue and green InGaN/GaN LEDs show that the EL peak wavelength of LEDs almost saturates at certain position with increasing injection currents. This proves the absence of polarization fields in the active region present in c‐plane structures.