bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spontaneous Assembly into Pseudopolyrotaxane Between Cyclodextrins and Biodegradable Polyphosphoester Ionomers
Authors: Tamura Atsushi , Tokunaga Masahiro , Iwasaki Yasuhiko , Yui Nobuhiko 
Published: March 2014

The development of novel biodegradable supermolecules is of importance in designing functionalized biomaterials utilized in the field of tissue engineering and drug delivery. In this regard, the focus here is on biocompatible and biodegradable polyphosphoester ionomers, and their pseudopolyrotaxane (PPRX) formation with α‐, β‐, or γ‐cyclodextrins (CDs) is examined. Poly(2‐hydroxy‐2‐oxo‐1,3,2‐dioxaphosphorane) (PHP) is found to form a precipitate upon mixing with α‐CD in water. Also, precipitation is observed by mixing PHP and γ‐CD, although its yield is lower than with α‐CD. The stoichiometry ratio of PHP monomer unit:α‐CD is determined to be 1:1 from the 1H NMR spectra of the precipitate. The wide‐angle X‐ray diffraction pattern of the precipitate between PHP and α‐CD clearly supports the formation of PPRX, and its crystalline structure is well consistent with previously reported α‐CD‐based PPRXs. This finding contributes to the design of novel supramolecular biomaterials.
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Alcohol intake and risk of Parkinson's disease: A meta‐analysis of observational studies
Authors: Zhang Dongfeng , Jiang Hong , Xie Junxia 
Published: March 2014

ABSTRACTBackgroundThe association of alcohol intake with risk of Parkinson's disease remains unclear.MethodsPertinent studies were identified in PubMed and EMBASE. The fixed‐effect or random‐effect model was selected based on heterogeneity. The dose‐response relationship was assessed by restricted cubic splines.ResultsWe included 32 articles, involving 677,550 subjects (9994 cases). The smoking‐adjusted risk of Parkinson's disease for the highest versus lowest level of alcohol intake was relative risk (RR) 0.78 (95% confidence interval [CI], 0.67‐0.92) overall, 0.86 (95% CI, 0.75‐0.995) in prospective studies, and 0.74 (95% CI, 0.58‐0.96) in matched case‐control studies. A significant association was found with beer (0.59; 95% CI, 0.39‐0.90) but not with wine and liquor, and for males (0.65; 95% CI, 0.47‐0.90) after a sensitivity analysis but not for females. The risk of Parkinson's disease decreased by 5% (0.95; 95% CI, 0.89‐1.02) for every 1 drink/day increment in alcohol intake in a linear (Pfor nonlinearity = 0.85) dose‐response manner.ConclusionsAlcohol intake, especially beer, might be inversely associated with risk of Parkinson's disease © 2014 International Parkinson and Movement Disorder Society
Peptide‐Based Proteasome Inhibitors in Anticancer Drug Design
Authors: Micale Nicola , Scarbaci Kety , Troiano Valeria , Ettari Roberta , Grasso Silvana , Zappalà Maria 
Published: March 2014

AbstractThe identification of the key role of the eukaryotic 26S proteasome in regulated intracellular proteolysis and its importance as a target in many pathological conditions wherein the proteasomal activity is defective (e.g., malignancies, autoimmune diseases, neurodegenerative diseases, etc.) prompted several research groups to the development of specific inhibitors of this multicatalytic complex with the aim of obtaining valid drug candidates. In regard to the anticancer therapy, the peptide boronate bortezomib (Velcade®) represents the first molecule approved by FDA for the treatment of multiple myeloma in 2003 and mantle cell lymphoma in 2006. Since then, a plethora of molecules targeting the proteasome have been identified as potential anticancer agents and a few of them reached clinical trials or are already in the market (i.e., carfilzomib; Kyprolis®). In most cases, the design of new proteasome inhibitors (PIs) takes into account a proven peptide or pseudopeptide motif as a base structure and places other chemical entities throughout the peptide skeleton in such a way to create an efficacious network of interactions within the catalytic sites. The purpose of this review is to provide an in‐depth look at the current state of the research in the field of peptide‐based PIs, specifically those ones that might find an application as anticancer agents.
Global analysis of virus dynamics model with logistic mitosis, cure rate and delay in virus production
Authors: Vargas‐De‐León Cruz , Chí Noé Chan , Vales Eric Ávila 
Published: March 2014

AbstractIn this paper, we study a virus dynamics model with logistic mitosis, cure rate, and intracellular delay. By means of construction of a suitable Lyapunov functionals, obtained by linear combinations of Volterra—type functions, composite quadratic functions and Volterra—type functionals, we provide the global stability for this model. IfR0, the basic reproductive number, satisfiesR0 ≤ 1, then the infection‐free equilibrium state is globally asymptotically stable. Our system is persistent ifR0 > 1. On the other hand, ifR0 > 1, then infection‐free equilibrium becomes unstable and a unique infected equilibrium exists. The local stability analysis is carried out for the infected equilibrium, and it is shown that, if the parameters satisfy a condition, the infected equilibrium can be unstable and a Hopf bifurcation can occur. We also have that ifR0 > 1, then the infected equilibrium state is globally asymptotically stable if a sufficient condition is satisfied. We illustrate our findings with some numerical simulations. Copyright © 2014 John Wiley & Sons, Ltd.
Detection of glutamate, glutamine, and glutathione by radiofrequency suppression and echo time optimization at 7 tesla
Authors: An Li , Li Shizhe , Murdoch James B. , Araneta Maria Ferraris , Johnson Christopher , Shen Jun 
Published: March 2014

PurposeTo achieve detection of glutamate (Glu), glutamine (Gln), and glutathione (GSH) by minimizing the N‐acetyl‐aspartate (NAA) multiplet signals at 2.49 ppm using a echo time (TE) ‐optimized PRESS pulse sequence and a novel J‐suppression radiofrequency pulse.MethodsUsing density matrix simulations, a PRESS sequence with (TE1, TE2) = (69, 37) ms and an inserted 90° J‐suppression pulse were found to minimize the NAA multiplet at 2.49 ppm.ResultsNAA phantom experiments confirmed the successful suppression of the NAA multiplet at 2.49 ppm. A study of eight healthy volunteers found both Glu and Gln to be significantly higher in gray matter (GM) dominant medial prefrontal cortex voxels than in white matter (WM) dominant right frontal cortex voxels. Time‐course 1H spectra acquired during intravenous [U‐13C6]glucose infusion showed gradually changing Glu C4 and Gln C4 proton resonance signals in a spectral pattern predicted by numerical simulations.ConclusionReliable detection of Glu, Gln, and GSH was achieved. Glu and Gln levels were significantly higher in frontal lobe GM than in frontal lobe WM. It is feasible to use the proposed proton MR spectroscopy method to measure the kinetics of 13C incorporation into Glu and Gln during infusion of 13C labeled glucose. Magn Reson Med 73:451–458, 2015. © 2014 Wiley Periodicals, Inc.
A double‐quadrature radiofrequency coil design for proton‐decoupled carbon‐13 magnetic resonance spectroscopy in humans at 7T
Authors: Roig Eulalia Serés , Magill Arthur W. , Donati Guillaume , Meyerspeer Martin , Xin Lijing , Ipek Ozlem , Gruetter Rolf 
Published: March 2014

PurposeCarbon‐13 magnetic resonance spectroscopy (13C‐MRS) is challenging because of the inherent low sensitivity of 13C detection and the need for radiofrequency transmission at the 1H frequency while receiving the 13C signal, the latter requiring electrical decoupling of the 13C and 1H radiofrequency channels. In this study, we added traps to the 13C coil to construct a quadrature‐13C/quadrature‐1H surface coil, with sufficient isolation between channels to allow simultaneous operation at both frequencies without compromise in coil performance.MethodsIsolation between channels was evaluated on the bench by measuring all coupling parameters. The quadrature mode of the quadrature‐13C coil was assessed using in vitro 23Na gradient echo images. The signal‐to‐noise ratio (SNR) was measured on the glycogen and glucose resonances by 13C‐MRS in vitro, compared with that obtained with a linear‐13C/quadrature‐1H coil, and validated by 13C‐MRS in vivo in the human calf at 7T.ResultsIsolation between channels was better than −30 dB. The 23Na gradient echo images indicate a region where the field is strongly circularly polarized. The quadrature coil provided an SNR enhancement over a linear coil of 1.4, in vitro and in vivo.ConclusionIt is feasible to construct a double‐quadrature 13C‐1H surface coil for proton decoupled sensitivity enhanced 13C‐NMR spectroscopy in humans at 7T. Magn Reson Med 73:894–900, 2015. © 2014 Wiley Periodicals, Inc.
Wavelet analysis of quadriceps power spectra and amplitude under varying levels of contraction intensity and velocity
Authors: Croce Ronald , Miller John , Chamberlin Kent , Filipovic David , Smith Wayne 
Published: March 2014

ABSTRACTIntroduction: We investigated the effect of contraction intensity [100%, 75%, 50%, and 25% maximum voluntary contraction (MVC)] and movement velocity (50°, 100°, 200°, and 400°/s) on surface electromyography root mean square amplitude (SEMGRMS) and median frequency (SEMGMDF) of rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM). Methods: SEMGs during knee extension were resolved into their respective frequencies using wavelet transformations. Results: RF, VL, and VM muscles displayed increased SEMGMDF as contraction intensity increased from 25% to 50% MVC and from 75% to 100% MVC, and each muscle displayed its own unique frequency shifting patterns. The SEMGMDF was not influenced by movement velocity. SEMGRMS increased in all 3 muscles as contraction intensity increased and was influenced by movement velocity, with the highest values observed at 400° and 200°/s. Conclusions: We infer that increasing contraction intensity facilitates greater recruitment of fast‐twitch muscle fibers, but there are differing responses in RF, VL, and VM muscles. Muscle Nerve 50: 844–853, 2014
Interface Jacobian‐based Co‐Simulation
Authors: Sicklinger S. , Belsky V. , Engelmann B. , Elmqvist H. , Olsson H. , Wüchner R. , Bletzinger K.‐U. 
Published: March 2014

SUMMARYCo‐simulation is a prominent method to solve multi‐physics problems. Multi‐physics simulations using a co‐simulation approach have an intrinsic advantage. They allow well‐established and specialized simulation tools for different fields and signals to be combined and reused with minor adaptations in contrast to the monolithic approach. However, the partitioned treatment of the coupled system poses the drawback of stability and accuracy challenges. If several different subsystems are used to form the co‐simulation scenario, these issues are especially important. In this work, we propose a new co‐simulation algorithm based on interface Jacobians. It allows for the stable and accurate solution of complex co‐simulation scenarios involving several different subsystems. Furthermore, the Interface Jacobian‐based Co‐Simulation Algorithm is formulated such that it enables parallel execution of the participating subsystems. This results in a high‐efficient procedure. Furthermore, the Interface Jacobian‐based Co‐Simulation Algorithm handles algebraic loops as the co‐simulation scenario is defined in residual form. Copyright © 2014 John Wiley & Sons, Ltd.
Simplified first‐trimester fetal cardiac screening (four chamber view and ventricular outflow tracts) in a low‐risk population
Authors: Orlandi Emanuela , Rossi Cinzia , Perino Antonio , Musicò Giulia , Orlandi Francesco 
Published: March 2014

ABSTRACTObjectivesOur aim was to assess the accuracy of a simplified fetal cardiac study, inclusive of four‐chamber view (4CV) and ventricular outflow tracts, performed during the 11–14 week screening by well‐trained obstetricians to detect congenital heart diseases (CHDs).MethodsA transabdominal ultrasound was performed on 4820 singleton pregnant women at 11–14 weeks to visualize the visceral site, the 4CV, and the outflow tracts. Neonatal outcomes were recorded 6 and 12 months after birth.ResultsAmong the 4820 patients reviewed, 790 were excluded because of loss at prenatal or postnatal follow‐up (649 cases), or inability to obtain adequate first‐trimester sonographic cardiac evaluation (141 cases). Among the 4030 included cases, 32 CHD cases were detected (20 major and 12 minor); 18 of the major (90%) and five of the minor (42%) were detected or suspected in the first trimester, one major and six minor in the second trimester, and one major and one minor only after birth.ConclusionsA simplified protocol is an effective tool to screen for CHD at 11–14 weeks. © 2014 John Wiley & Sons, Ltd.
Effects of acid treatment at different temperatures on the surface dielectric properties of low‐density polyethylene
Authors: Simonović Kosta , Petronijević Ivan , Kostoski Dušan , Dojčilović Jablan , Luyt Adriaan S , Dudić Duško 
Published: March 2014

AbstractThe surface dielectric properties of acid‐etched low‐density polyethylene (LDPE) were analysed in the frequency range from 20 Hz to 200kHz. Samples were treated with various acids for a period of one hour, at temperatures ranging from 20 to 70 °C. After the treatment, the samples were analysed with Fourier transform infrared spectroscopy, revealing chemical and crystallinity changes on the surface, as a direct result of the treatment. The sample surfaces were analysed using atomic force microscopy. The micrographs show that the acid treatment increases the roughness of the samples. Compared to untreatedLDPE, the etched samples may exhibit significantly different conductance values at low frequencies. It is also observed that an increase in the acid treatment temperature can result in lower values of conductance and susceptance compared to untreated samples.LDPEfilms with low value of surfaceACconductivity after acid treatment are potentially useful substrates for high‐speed electro‐sensing applications. The presented results indicate that a suitable choice of acid treatment ofLDPEcan effect surface polarization while preserving low values of surfaceACconductivity of the polymer. © 2014 Society of Chemical Industry
Solution structure of lysine‐free (K0) ubiquitin
Authors: Huang Tao , Li Jess , Byrd R. Andrew 
Published: March 2014

AbstractLysine‐free ubiquitin (K0‐Ub) is commonly used to study the ubiquitin‐signaling pathway, where it is assumed to have the same structure and function as wild‐type ubiquitin (wt‐Ub). However, the K0‐Ub 15N heteronuclear single quantum correlation NMR spectrum differs significantly from wt‐Ub and the melting temperature is depressed by 19°C, raising the question of the structural integrity and equivalence to wt‐Ub. The three‐dimensional structure of K0‐Ub was determined by solution NMR, using chemical shift and residual dipolar coupling data. K0‐Ub adopts the same backbone structure as wt‐Ub, and all significant chemical shifts can be related to interactions impacted by the K to R mutations.
Database search of spontaneous reports and pharmacological investigations on the sulfonylureas and glinides‐induced atrophy in skeletal muscle
Authors: Mele Antonietta , Calzolaro Sara , Cannone Gianluigi , Cetrone Michela , Conte Diana , Tricarico Domenico 
Published: March 2014

AbstractThe ATP‐sensitive K+ (KATP) channel is an emerging pathway in the skeletal muscle atrophy which is a comorbidity condition in diabetes. The “in vitro” effects of the sulfonylureas and glinides were evaluated on the protein content/muscle weight, fibers viability, mitochondrial succinic dehydrogenases (SDH) activity, and channel currents in oxidative soleus (SOL), glycolitic/oxidative flexor digitorum brevis (FDB), and glycolitic extensor digitorum longus (EDL) muscle fibers of mice using biochemical and cell‐counting Kit‐8 assay, image analysis, and patch‐clamp techniques. The sulfonylureas were: tolbutamide, glibenclamide, and glimepiride; the glinides were: repaglinide and nateglinide. Food and Drug Administration‐Adverse Effects Reporting System (FDA‐AERS) database searching of atrophy‐related signals associated with the use of these drugs in humans has been performed. The drugs after 24 h of incubation time reduced the protein content/muscle weight and fibers viability more effectively in FDB and SOL than in the EDL. The order of efficacy of the drugs in reducing the protein content in FDB was: repaglinide (EC50 = 5.21 × 10−6) ≥ glibenclamide(EC50 = 8.84 × 10−6) > glimepiride(EC50 = 2.93 × 10−5) > tolbutamide(EC50 = 1.07 × 10−4) > nateglinide(EC50 = 1.61 × 10−4) and it was: repaglinide(7.15 × 10−5) ≥ glibenclamide(EC50 = 9.10 × 10−5) > nateglinide(EC50 = 1.80 × 10−4) ≥ tolbutamide(EC50 = 2.19 × 10−4) > glimepiride(EC50=–) in SOL. The drug‐induced atrophy can be explained by the KATP channel block and by the enhancement of the mitochondrial SDH activity. In an 8‐month period, muscle atrophy was found in 0.27% of the glibenclamide reports in humans and in 0.022% of the other not sulfonylureas and glinides drugs. No reports of atrophy were found for the other sulfonylureas and glinides in the FDA‐AERS. Glibenclamide induces atrophy in animal experiments and in human patients. Glimepiride shows less potential for inducing atrophy.
Concise Review: The Role of C-kit Expressing Cells in Heart Repair at the Neonatal and Adult Stage
Authors: Hesse Michael , Fleischmann Bernd K. , Kotlikoff Michael I. 
Published: March 2014

AbstractIschemic heart disease is the number one cause of morbidity and mortality in the developed world due to the inability of the heart to replace lost myocytes. The cause of postinfarction myogenic failure has been a subject of intense scientific investigation and much controversy. Recent data indicate a brief perinatal developmental window exists during which postinfarction myogenesis, and substantial heart regeneration, occurs. By contrast, repair of an equivalent injury of the adult heart results in prominent revascularization without myogenesis. Here, we review recent experiments on neonatal postinjury myogenesis, examine the mechanistic hypotheses of dedifferentiation and precursor expansion, and discuss experiments indicating that postinfarction revascularization derives primarily from cardiac vascular precursors. These data have profound consequences for the understanding of human heart repair, as they address the long standing question as to whether human postinfarction myogenic failure is due to the loss of precursors existent at the neonatal stage or to a context-dependent inhibition of these precursors within the infarct, and suggest strategies for the recapitulation of neonatal myogenic capacity and the augmentation of revascularization. Stem Cells 2014;32:1701–1712
Vulnerability of steel moment‐resisting frames under effects of forward directivity
Authors: Gerami Mohsen , Abdollahzadeh Davood 
Published: March 2014

SummaryIn near‐fault regions, forward directivity causes long‐period pulse‐like motions with high amplitude and short duration perpendicular to the fault surface. Pulse‐like motions have important roles in forming the distribution of damages over the structure height. Recent studies indicate that the number of spans influences the demand distribution over the moment frame's height. Considering the destruction of the buildings near causative fault in Bam earthquake, Iran (2003) demonstrates that most damages are concentrated in the ground floor of moment frames. Hence, in this study, forward directivity effect on vulnerability distribution of steel moment‐resisting frames with a few number of spans has been studied by nonlinear dynamic analysis of five structural models with different heights under 20 earthquake records. Related to frames height, results showed that 70% to 90% of forward directivity effects are accumulated in lower one‐third or half of model's height. Also, in near field of fault, growing rate of ductility demand at lower parts of model's height is two times higher than that of far‐fault regions. In addition, it was observed that ductility capacity in lower half of low‐rise or one‐third of high‐rise models has a key role in stability of moment frames under near‐fault pulse‐like motions. Copyright © 2014 John Wiley & Sons, Ltd.
Sensorless IPMSM position estimation based on multi SVPWM with elimination of inverter nonlinear effects
Authors: Gu Minglei , Ogasawara Satoshi , Takemoto Masatsugu 
Published: March 2014

AbstractThis paper presents a position‐sensorless interior permanent magnet synchronous motor (IPMSM) control system at low and zero speed based on a multi‐space‐vector pulse‐width modulation (MSVPWM) pattern with the elimination of nonlinear inverter effects. In conventional sensorless methods based on the MSVPWM pattern, the high‐frequency (HF) components of voltage and current are used to estimate the rotor position information. However, the inverter nonlinear effects, such as forward voltage drops and deadtime, distort the HF components of the voltage and current so that an error occurs in the position estimation. Therefore, an improved position estimation scheme is developed in this paper. The compensated HF components of the voltage taking account of the inverter nonlinear effects can be used to decrease the estimation error. The proposed method can be implemented without increasing any hardware cost. Experimental results confirm the effectiveness of the proposed method. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Gradually Releasing Responsibility to Students Writing Persuasive Text
Authors: Read Sylvia , Landon‐Hays Melanie , Martin‐Rivas Alicia 
Published: March 2014

AbstractThe emphasis on improving writing instruction, especially the writing of non‐narrative texts, may lead some teachers to seek effective ways to teach students. The IMSCI model, a scaffolded model for writing instruction, is useful for planning effective instruction. This article describes a research project conducted in a 4th grade classroom emphasizing the combined benefits of scaffolded instruction and genre study and testing scaffolded persuasive writing lessons based on the IMSCI model. Researchers wrote lesson plans using the IMSCI model as the underlying structure and tied the lessons to science objectives for fourth grade. Teachers implemented the lessons in their classrooms and student essays were collected as data. Results from this study suggest there are positive outcomes in student writing as a result of a focus on genre in a scaffolded instructional setting.