bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitive profiling of biogenic amines in urine using CE with transient isotachophoretic preconcentration
Authors: Xu Zhongqi , Okada Jiro , Timerbaev Andrei R. , Hirokawa Takeshi 
Published: October 2009

AbstractA transient ITP‐CZE system is proposed for the determination of biogenic amines in urine. The complete separation and identification of dopamine, tyramine (TA), tryptamine (T), serotonin, epinephrine, norepinephrine, and normetanephrine have been achieved in a twofold diluted urine sample (in which the analytes were below the LODs by normal CZE). The tITP preconcentration conditions were created by introducing a 30 mM solution of NaOH, containing 0.1% hydroxypropylcellulose (pH 6.5 adjusted with MES), and 0.1 M HCl before and after the sample zone to work as leading and terminating electrolytes, respectively. This allowed the LODs of direct UV absorption detection to be decreased down to the 10–8 M level that is comparable with the sensitivity thresholds of LIF detection or inline SPE‐CE. The RSDs of migration time and peak area for real‐biofluid analysis were in the range of 0.1–4.5% and 0.8–16% (n=3), respectively. Quantification of dopamine, TA, T, and serotonin was performed using internal calibration. To the best of our knowledge, this is the first report on probing urinal biogenic amines and their metabolites by tITP‐CZE.
Kinetics of neuromuscular changes during low‐frequency electrical stimulation
Authors: Papaiordanidou Maria , Guiraud David , Varray Alain 
Published: October 2009

AbstractThe purpose of the study was to examine the time course of neuromuscular fatigue components during a low‐frequency electrostimulation (ES) session. Three bouts of 17 trains of stimulation at 30 HZ (4 s on, 6 s off) were used to electrically induce fatigue in the plantar flexor muscles. Before and after every 17‐train bout, torque, electromyographic activity [expressed as root mean square (RMS) and median frequency (MF) values], evoked potentials (M‐wave and H‐reflex), and the level of voluntary activation (LOA, using twitch interpolation technique) were assessed. Torque during maximal voluntary contraction decreased significantly from the very first stimulation bout (−6.6 ± 1.11%, P < 0.001) and throughout the session (−10.32 ± 1.68% and −11.53 ± 1.27%, for the second and third bouts, respectively). The LOA and RMS/Mmax values were significantly decreased during the ES session (−2.9 ± 1.07% and −17.5 ± 6.14%, P < 0.01 and P< 0.001, respectively, at the end of the protocol), while MF showed no changes. The Hmax/Mmax ratio and Mmax were not significantly modified during the session. All twitch parameters were significantly potentiated after the first bout and throughout the session (P < 0.001). The maximal torque decrease was evident from the early phase of a low‐frequency ES protocol, with no concomitant inhibition of motoneuron excitability or depression of muscle contractile properties. These results are consistent with an early failure of the central drive to the muscle. Muscle Nerve, 2010
Early effects of carbachol on the morphology of motor endplates of mammalian skeletal muscle fibers
Authors: Voigt Tilman 
Published: October 2009

AbstractLong‐term disturbance of the calcium homeostasis of motor endplates (MEPs) causes necrosis of muscle fibers. The onset of morphological changes in response to this disturbance, particularly in relation to the fiber type, is presently unknown. Omohyoid muscles of mice were incubated for 1–30 minutes in 0.1 mM carbachol, an acetylcholine agonist that causes an inward calcium current. In these muscles, the structural changes of the sarcomeres and the MEP sarcoplasm were evaluated at the light‐ and electron‐microscopic level. Predominantly in type I fibers, carbachol incubation resulted in strong contractures of the sarcomeres underlying the MEPs. Owing to these contractures, the usual beret‐like form of the MEP‐associated sarcoplasm was deformed into a mushroom‐like body. Consequently, the squeezed MEPs partially overlapped the adjacent muscle fiber segments. There are no signs of contractures below the MEPs if muscles were incubated in carbachol in calcium‐free Tyrode's solution. Carbachol induced inward calcium current and produced fiber‐type–specific contractures. This finding points to differences in the handling of calcium in MEPs. Possible mechanisms for these fiber‐type–specific differences caused by carbachol‐induced calcium entry are assessed. Muscle Nerve, 2009
Joint angle dependence of intermuscle difference in postactivation potentiation
Authors: Miyamoto Naokazu , Mitsukawa Naotoshi , Sugisaki Norihide , Fukunaga Tetsuo , Kawakami Yasuo 
Published: October 2009

AbstractThe purpose of this study was to examine the effect of ankle joint angle on the intermuscle difference in postactivation potentiation (PAP) between the medial gastrocnemius (MG) and soleus (SOL) muscles. At the neutral position of joint angle, dorsiflexion of 20°, and plantarflexion of 20°, twitch responses were evoked by stimulating the posterior tibial nerve with supramaximal intensity before and after a 10‐s maximal voluntary plantarflexion at each joint angle. Mechanical properties of the MG and SOL muscles were assessed simultaneously and separately by using mechanomyography (MMG), and the extent of potentiation of each muscle was evaluated by peak‐to‐peak amplitude of the MMG signal. The MG showed greater potentiation than the soleus after the conditioning MVC in the neutral and dorsiflexion position, while in the plantarflexion position no significant difference was found in PAP between MG and SOL. These results suggest that the difference in the magnitude of PAP between synergistic muscles is determined by a combination of the joint angle‐ and fiber composition‐dependence of PAP. Muscle Nerve, 2010
Synthesis and properties of bismuth oxide nanoshell coated polyaniline nanoparticles for promising photovoltaic properties
Authors: Mahmoud Waleed E. , Al‐Ghamdi A. A. 
Published: October 2009

AbstractA novel heterostructure made of polyaniline (PANI) nanoparticles coated by nanolayer of bismuth oxide Bi2O3 was synthesized. The structure was characterized by scanning electron microscopy, X‐ray diffraction, and transmission electron microscopy. These characterizations showed that the bismuth oxide nanoshell was pure and crystalline, and has thickness in the range of 10 nm. The experiment on photoluminescence (PL) of Bi2O3 nanoshell coated polyaniline nanoparticle, at room temperature, shows an emission band peaked at around 385 nm. When compared with the PL spectrum of Bi2O3 nanoparticles, about 100 times PL enhancement was found in the PL spectrum of Bi2O3 nanoshell coated polyaniline nanoparticle. The current density versus voltage (J–V) measurements in dark and illumination showed that this heterojunction has 4 orders of magnitude rectification in the dark and 3 orders of magnitude rectification under illumination. The obtained power conversion efficiency of polyaniline nanoparticles coated by nanoshell of bismuth oxide (η = 7.453%) was much enhanced compared with polyaniline alone (η = 8.33 × 10−4%) this indicates that the prepared heterostructure represents a promising photovoltaic solar cell. Copyright © 2009 John Wiley & Sons, Ltd.
Blood‐feeding and immunogenic Aedes aegypti saliva proteins
Authors: Wasinpiyamongkol Ladawan , Patramool Sirilaksana , Luplertlop Natthanej , Surasombatpattana Pornapat , Doucoure Souleymane , Mouchet François , Séveno Martial , Remoue Franck , Demettre Edith , Brizard Jean‐Paul , Jouin Patrick , Biron David G. , Thomas Frédéric , Missé Dorothée 
Published: October 2009

AbstractMosquito‐transmitted pathogens pass through the insect's midgut (MG) and salivary gland (SG). What occurs in these organs in response to a blood meal is poorly understood, but identifying the physiological differences between sugar‐fed and blood‐fed (BF) mosquitoes could shed light on factors important in pathogens transmission. We compared differential protein expression in the MGs and SGs of female Aedes aegypti mosquitoes after a sugar‐ or blood‐based diet. No difference was observed in the MG protein expression levels but certain SG proteins were highly expressed only in BF mosquitoes. In sugar‐fed mosquitoes, housekeeping proteins were highly expressed (especially those related to energy metabolism) and actin was up‐regulated. The immunofluorescence assay shows that there is no disruption of the SG cytoskeletal after the blood meal. We have generated for the first time the 2‐DE profiles of immunogenic Ae. aegypti SG BF‐related proteins. These new data could contribute to the understanding of the physiological processes that appear during the blood meal.
Computational studies of the cone and 1,2,3 alternate calix[6]arene bis‐crown‐4 isomers: structures, NMR shifts, atomic charges, and steric compression
Authors: Lawson Meghan N. , Blanda Michael T. , Staggs Sara J. , Sederholm Lauren N. , Easter David C. 
Published: October 2009

AbstractThe cone and 1,2,3 alternate isomers of calix[6]arene bis‐crown‐4 were investigated computationally. Structural optimizations, energies, bond distances, and Mulliken charges were calculated by the application of the B3LYP/6‐31g(d) method/basis, followed by NMR calculations via both B3LYP/6‐31g(d) and HF/6‐31g(d). Calculations were completed at three different levels of imposed symmetry, and two calculations investigated the chloroform solvent effects. Better NMR results were obtained from HF/6‐31g(d) calculations that did not impose molecular symmetry constraints. Consideration of solvent effects improved ground state energies, but other improvements were minimal and not significant enough to justify the added computational expense of solvent calculations. Overall results are consistent with known experimental assignments and were valuable for assigning previously unknown NMR peaks. Net charges, electrostatic forces, and local dipoles – but not bond lengths – are strongly correlated to spectroscopic manifestations of steric compression. Copyright © 2009 John Wiley & Sons, Ltd.
Photochromic behavior of several new synthesized dyes via Zincke salts
Authors: Mahmoodi N. O. , Mamaghani M. , Ghanadzadeh A. , Arvand M. , Fesanghari M. 
Published: October 2009

AbstractSynthesis of several ‘dyes’, analogs of retinal imine visual pigment via nucleophilic attack of some secondary amines to pyridinium salts following precyclic ring‐opening reaction, is discussed. The photochromic properties of these dyes have been studied by UV‐Vis spectroscopy under irradiation of UV light. Copyright © 2009 John Wiley & Sons, Ltd.
PRIMO/PRIMONA: A coarse‐grained model for proteins and nucleic acids that preserves near‐atomistic accuracy
Authors: Gopal Srinivasa M. , Mukherjee Shayantani , Cheng Yi‐Ming , Feig Michael 
Published: October 2009

AbstractThe new coarse graining model PRIMO/PRIMONA for proteins and nucleic acids is proposed. This model combines one to several heavy atoms into coarse‐grained sites that are chosen to allow an analytical, high‐resolution reconstruction of all‐atom models based on molecular bonding geometry constraints. The accuracy of proposed reconstruction method in terms of structure and energetics is tested and compared with other popular reconstruction methods for a variety of protein and nucleic acid test sets. Proteins 2010. © 2009 Wiley‐Liss, Inc.
Protein structure prediction begins well but ends badly
Authors: Saunders Rhodri , Deane Charlotte M. 
Published: October 2009

AbstractThe accurate prediction of protein structure, both secondary and tertiary, is an ongoing problem. Over the years, many approaches have been implemented and assessed. Most prediction algorithms start with the entire amino acid sequence and treat all residues in an identical fashion independent of sequence position. Here, we analyze blind prediction data to investigate whether predictive capability varies along the chain. Free modeling results from recent critical assessment of techniques for protein structure prediction (CASP) experiments are evaluated; as is the most up‐to‐date data from EVA, a fully automated blind test of secondary structure prediction servers. The results demonstrate that structure prediction accuracy is dependent on sequence position. Both secondary structure and tertiary structure predictions are more accurate in regions near the amino(N)‐terminus when compared with analogous regions near the carboxy(C)‐terminus. Eight of 10 secondary structure prediction algorithms assessed by EVA perform significantly better in regions at the N‐terminus. CASP data shows a similar bias, with N‐terminal fragments being predicted more accurately than fragments from the C‐terminus. Two analogous fragments are taken from each model, the N‐terminal fragment begins at the start of the most N‐terminal secondary structure element (SSE), whereas the C‐terminal fragment finishes at the end of the most C‐terminal SSE. Each fragment is locally superimposed onto its respective native fragment. The relative terminal prediction accuracy (RMSD) is calculated on an intramodel basis. At a fragment length of 20 residues, the N‐terminal fragment is predicted with greater accuracy in 79% of cases. Proteins 2010. © 2009 Wiley‐Liss, Inc.
Solution structure and dynamics of human ubiquitin conjugating enzyme Ube2g2
Authors: Ju Tingting , Bocik William , Majumdar Ananya , Tolman Joel R. 
Published: October 2009

AbstractUbe2g2 is an E2 enzyme which functions as part of the endoplasmic reticulum‐associated degradation (ERAD) pathway responsible for identification and degradation of misfolded proteins in the endoplasmic reticulum. In tandem with a cognate E3 ligase, Ube2g2 assembles K48‐linked polyubiquitin chains and then transfers them to substrate, leading ultimately to proteasomal degradation of the polyubiquitin‐tagged substrate. We report here the solution structure and backbone dynamics of Ube2g2 solved by nuclear magnetic resonance spectroscopy. Although the solution structure agrees well with crystallographic structures for the E2 core, catalytically important loops (encompassing residues 95–107 and 130–135) flanking the active site cysteine are poorly defined. 15N spin relaxation and residual dipolar coupling analysis directly demonstrates that these two loops are highly dynamic in solution. These results suggest that Ube2g2 requires one or more of its protein partners, such as cognate E3, acceptor ubiquitin substrate or thiolester‐linked donor ubiquitin, to assume its catalytically relevant conformation. Within the NMR structural ensemble, interactions were observed between His94 and the highly mobile loop residues Asp98 and Asp99, supporting a possible role for His94 as a general base activated by the carboxylate side‐chains of Asp98 or Asp99. Proteins 2010. © 2009 Wiley‐Liss, Inc.
Photoluminescence properties of blue‐emitting Sr2LiSiO4F:Ce3+,Li+ phosphor
Authors: Zhang Xinmin , Seo Hyo Jin 
Published: October 2009

AbstractSr2LiSiO4F:Ce3+,Li+ phosphors have been synthesized by solid‐state reaction. The photoluminescence (PL) emission and excitation behavior of blue‐emitting Sr2LiSiO4F:Ce3+,Li+ phosphors have been reported. Three dominant bands centered at about 250, 280, and 340 nm characterized the excitation spectra, which are consistent with the diffuse reflection spectra. Under the excitation of different UV light, the peak of the emission spectrum shifts. The PL excitation spectra monitored by different emission wavelength, the PL excitation spectra of different dopant concentration, and the optimum dopant content have been studied in detail.
Simultaneous stress and defect luminescence study on silicon
Authors: Gundel Paul , Schubert Martin C. , Warta Wilhelm 
Published: October 2009

AbstractInternal stress is strongly correlated with the mechanical stability of silicon wafers and with the distribution of defects and thus the minority carrier lifetime, which is often the limiting parameter for multicrystalline (mc) silicon solar cells. Therefore, internal stress is a highly relevant parameter for mc silicon. In this paper, a qualitative internal stress measurement technique by photoluminescence spectroscopy for mc silicon is presented. This technique is based on the stress‐induced‐bandgap energy shift. Stress measurements are compared to defect luminescence images, which are gathered in the same measurement. The method is evaluated by stress measurements with micro‐Raman spectroscopy.
Diffraction from quasi one‐dimensional crystals and nanotubes
Authors: Damnjanović M. , Vuković T. , Milošević I. 
Published: October 2009

AbstractIntensity distribution for diffraction from arbitrary quasi one‐dimensional crystal is calculated with the help of symmetry classification of such systems onto 15 conformation classes. Characteristic features of patterns are discussed. In particular, carbon nanotubes are single‐orbit systems generated by the fifth family line groups. It is shown how the identification of single‐wall tubes can be performed in two steps: at first we reconstruct the line group from the pattern, and afterwards the chirality indices are found easily due to the bi‐unique correspondence of the single‐wall carbon nanotubes and their symmetry groups. A comment on the diffraction from double‐ and multi‐wall nanotubes is made.
Properties of the exponential EWMA chart with parameter estimation
Authors: Ozsan Guney , Testik Murat Caner , Weiß Christian H. 
Published: October 2009

AbstractCount rates may reach very low levels in production processes with low defect levels. In such settings, conventional control charts for counts may become ineffective since the occurrence of many samples with zero defects would cause control statistic to be consistently zero. Consequently, the exponentially weighted moving average (EWMA) control chart to monitor the time between successive events (TBE) or counts has been introduced as an effective approach for monitoring processes with low defect levels. When the counts occur according to a Poisson distribution, the TBE observations are distributed as exponential. Although the assumption of exponential distribution is a reasonable choice as a model of TBE observations, its parameter, i.e. the mean (also the standard deviation), is rarely known in practice and its estimate is used in place of the unknown parameter when constructing the exponential EWMA chart. In this article, we investigate the effects of parameter estimation on the performance measures (average run length, standard deviation, and percentiles of the run length distribution) of the exponential EWMA control chart. A comprehensive analysis of the conditional performance measures of the chart shows that the effect of estimation can be serious, especially if small samples are used. An investigation of the marginal performance measures, which are calculated by averaging the conditional performance measures over the distribution of the parameter estimator, allows us to provide explicit sample size recommendations in constructing these charts to reach a satisfactory performance in both the in‐control and the out‐of‐control situation. Copyright © 2009 John Wiley & Sons, Ltd.
Stabilization of linear systems with input delay and saturation—A parametric Lyapunov equation approach
Authors: Zhou Bin , Lin Zongli , Duan Guangren 
Published: October 2009

AbstractThis paper studies the problem of stabilizing a linear system with delayed and saturating feedback. It is known that the eigenstructure assignment‐based low‐gain feedback law (globally) stabilizes a linear system in the presence of arbitrarily large delay in its input, and semi‐globally stabilizes it when the input is also subject to saturation, as long as all its open‐loop poles are located in the closed left‐half plane. Based on a recently developed parametric Lyapunov equation‐based low‐gain feedback design method, this paper presents alternative, but simpler and more elegant, feedback laws that solve these problems. The advantages of this new approach include its simplicity, the capability of giving explicit conditions to guarantee the stability of the closed‐loop system, and the ease in scheduling the low‐gain parameter on line to achieve global stabilization in the presence of actuator saturation. Copyright © 2009 John Wiley & Sons, Ltd.
A simple analysis of a simple crossover trial with a dichotomous outcome measure
Authors: Schouten Hubert , Kester Arnold 
Published: October 2009

AbstractFor the two‐treatment two‐period crossover trial with a dichotomous outcome measure a simple and straightforward analysis is proposed: compute the treatment difference for each of the treatment sequences AB and BA, and then average over the sequence groups. The mean difference is used in the statistical test and in the computation of the 95 per cent confidence interval. The method is generalized to the case of a crossover trial including more than two treatments. Copyright © 2009 John Wiley & Sons, Ltd.
Conversation with a master: Brian L. Cochran
Authors: Carpenter Lauren , Mehrain Michael , Hart Gary C. 
Published: October 2009

AbstractBrian Cochran was born in 1930 and raised in Los Angeles, California. He attended the University of California, Los Angeles (UCLA), and graduated in 1954. He met his wife‐to‐be, Nancy, at UCLA, and they were married in March 1954 before Brian went into the Air Force. Brian spent 2 years with the Air Force at Elmendorf Air Force Base in Anchorage, Alaska. Copyright © 2009 John Wiley & Sons, Ltd.
Orthorhombic HP‐PrO2 – High‐Pressure Synthesis and Crystal Structure
Authors: Haberer Almut , Huppertz Hubert 
Published: October 2009

AbstractThe high‐pressure phase of PrO2 was synthesized under conditions of 5.5 GPa and 1000 °C in a Walker‐type multianvil apparatus. The crystal structure was determined on the basis of single‐crystal X‐ray diffraction data collected at room temperature. The title compound crystallizes in the orthorhombic α‐PbCl2‐type structure with the lattice parameters a = 637.6(3) pm, b = 384.4(2) pm, and c = 703.1(3) pm. The praseodymium ion is ninefold coordinated, the oxygen ions show either tetrahedral or square‐pyramidal coordination spheres.