bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atypically low spontaneous sister chromatid exchange formation in uveal melanoma
Authors: Hoh Leslie , Gravells Polly , Canovas David , Ul‐Hassan Aliya , Rennie Ian G. , Bryant Helen , Sisley Karen 
Published: October 2010

AbstractUveal melanoma (UM) is the most common primary intraocular cancer of adults and is characterized by several well‐established chromosomal changes. More recently, a specific mutation of guanine nucleotide binding protein Gq alpha subunit (GNAQ) has also been identified in a proportion of UM. Although some of these alterations have been suggested to be early changes, the genetic alterations responsible for the development of UM have yet to be clearly determined. Cancers are characterized by increased genetic instability, and analysis of established cancer cell lines and blood from cancer patients has universally been associated with an increased level of sister chromatid exchange (SCE). We have observed that the spontaneous frequency of SCE in primary cultures of UM and UM‐derived cell lines is decreased below normal baseline levels, a phenomenon unique to UM when compared with multiple other cancers. This finding was specific to the tumor and not found in lymphocytes from the patients. Although we cannot exclude the possibility that low SCE (LSCE) is peculiar to the uveal melanocytes lineage, as it was consistently observed in all UM studied, regardless of other genetic defects, we propose that this phenomenon contributes to the molecular pathogenesis of UM. © 2010 Wiley‐Liss, Inc.
CNBP: A multifunctional nucleic acid chaperone involved in cell death and proliferation control
Authors: Calcaterra Nora B. , Armas Pablo , Weiner Andrea M. J. , Borgognone Mariana 
Published: October 2010

AbstractCellular nucleic acid binding protein (CNBP) has been implicated in vertebrate craniofacial development and in myotonic dystrophy type 2 (DM2) and sporadic inclusion body myositis (sIBM) human diseases. In these seemingly unrelated biological processes, CNBP appears to be involved in controlling cell death and proliferation rates. Low levels of CNBP may reduce rate of global protein synthesis, thereby reducing proliferation and increasing apoptosis. Conversely, CNBP might affect transcription of genes required for cell proliferation. Experimental evidences gathered so far make it difficult to ascertain or rule out any of these possibilities. Moreover, both possibilities may not be mutually exclusive. CNBP is a small and strikingly conserved single‐stranded nucleic acid binding protein that is able to bind DNA as well as RNA. CNBP has a broad spectrum of targets, ranging from regulatory sites in gene promoters to translational regulatory elements in mRNA untranslated regions. Biochemical experiments have recently shed light on the possible mechanism of action for CNBP, which may act as a nucleic acid chaperone catalyzing the rearrangement of G‐rich nucleic acid secondary structures likely relevant for transcriptional and/or translational gene regulation. This review focuses on the involvement of CNBP in vertebrate craniofacial development and human DM2 and sIBM diseases, as well as on the biochemical and structural features of CNBP and its cellular and molecular mechanism of action. © 2010 IUBMB IUBMB Life, 62(10): 707–714, 2010
Functional and structural aspects of helicobacter pylori acidic stress response factors
Authors: Zanotti Giuseppe , Cendron Laura 
Published: October 2010

AbstractHelicobacter pylori is a striking example of adaptation of a bacterium to a very peculiar niche, the human stomach. Despite being a neutralophile, a sophisticated control of gene expression allows it to live and to proliferate in an environment that cycles from nearly neutral to very acidic. Despite the numerous studies performed on the mechanisms of acid adaptation, the physiological function of a large part of the genes products that are up‐regulated or down‐regulated is often not clear, in particular in the context of the response of the bacterium to an acidic stress. In this review, we discuss the molecular and functional aspects of some of the proteins that are commonly found overexpressed during the acid stress. © 2010 IUBMB IUBMB Life, 62(10): 715–723, 2010
A fitting formula for the falloff curves of unimolecular reactions, II: Tunneling effects
Authors: Zhang Peng , Law Chung K. 
Published: October 2010

AbstractBy taking into account effects of tunneling on the shape of the falloff curves of unimolecular reaction rate constants based on Troe's weak collision integral, a fitting formula for these curves is developed and then examined for several tunneling‐affected reactions. It is demonstrated that, compared to the widely used Troe's formula, the present expression not only substantially enhances the accuracy in fitting for tunneling‐affected reactions, but it is also computationally more efficient in its evaluation. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 43: 31–42, 2011
Monitoring fish oil volatiles to assess the quality of fish oil
Authors: Sullivan Jenna C. , Budge Suzanne M. 
Published: October 2010

AbstractThe fish oil industry is continuously growing; however there is a lack of analytical methods to assess fish oil quality that correlate with the results obtained through sensory testing. Solid phase microextraction (SPME) provides a means to monitor the concentration of oxidative volatiles in fish oil. Because volatile oxidation products are responsible for the off‐flavours found in oxidized fish oil, this technique may be used as a substitute for sensory panels. Principal component analysis (PCA), combined with sensory panels, can be used to determine the oxidation products that are most correlated with degradation of the sensory properties of the oil. This creates the potential for development of methods that can determine when the sensory qualities of oil have deteriorated beyond an acceptable level.
Controlled Fluorescence Resonance Energy Transfer from Multiple Fluorophores in Layer‐by‐Layer Assemblies
Authors: Kim Ki‐Se , Yoo Seong Il , Kim Minsoo , Sohn Byeong‐Hyeok 
Published: October 2010

AbstractWe demonstrate precise control of multiple FRET within LbL assemblies to produce simultaneous light emission with enhanced intensity from a single excitation with a blue wavelength. Three different fluorescent dyes were attached to neat polyelectrolytes and then incorporated into the LbL assembly. With designed deposition sequence, the layer of blue‐absorbing dyes was placed in the adjacent layer of green‐ and red‐emitting dyes, while the layers of emitting dyes were separated with each other beyond their Förster radius by inserting neat polyelectrolytes between them. The LbL assemblies not only allowed FRET from the absorbing dyes to the emitting dyes but also prohibited FRET between the emitting dyes to produce simultaneously enhanced green and red emission. magnified image
Reversible Electrogelation in Poly(acrylic acid) Aqueous Solutions Triggered by Redox Reactions of Counterions
Authors: He Shuying , Ren Biye , Liu Xinxing , Tong Zhen 
Published: October 2010

AbstractA facile, electrically induced reversible gelation in a PAA aqueous solution containing Fe ions has been realized. The PAA solution is converted into a homogeneous hydrogel when the ferrous ions are electro‐oxidized to ferric ions and this gel is restored to solution by electro‐reduction of the ferric ions to ferrous ions. This sol/gel transition is completely reversible by changing the electrode polarity. The stoichiometric relation between the gel weight and charge quantity is investigated by chronocoulometry and no saturation for gelation is observed even after 5 000 s. The cyclic voltammetry and polarization current have been measured on this gelation system to reveal the kinetic reversibility and redox species of the electrode process under specified electric potential.
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Synthesis and Photovoltaic Properties of Conjugated Copolymers with Benzo[1,2‐b:4,5‐b′]dithiophene and Bis(thiophene)phthalimide Units
Authors: Zhang Guobing , Fu Yingying , Zhang Qing , Xie Zhiyuan 
Published: October 2010

AbstractTwo new donor/acceptor copolymers PBDTPhBT1 and PBDTPhBT2 with alternating benzodithiophene (BDT) and bisthiophene‐phthalimide (PhBT) units were synthesized by Stille coupling reaction. The copolymers showed identical optical bandgaps of 1.98 eV. The HOMO energy levels are −5.35 and −5.32 eV for PBDTPhBT1 and PBDTPhBT2, respectively. The bulk heterojunction solar cell devices based on these copolymers as donors and PC71BM as acceptor displayed high open‐circuit voltages of 0.90–0.93 V and achieved power conversion efficiency of 1.54% under the illumination of AM 1.5, 100 mW · cm−2.
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Nanofibers by Green Electrospinning of Aqueous Suspensions of Biodegradable Block Copolyesters for Applications in Medicine, Pharmacy and Agriculture
Authors: Sun Jinyuan , Bubel Kathrin , Chen Fei , Kissel Thomas , Agarwal Seema , Greiner Andreas 
Published: October 2010

AbstractPoly(hexamethylene adipate)‐PEO block copolymers (PHA‐b‐PEO) with different PEO contents were synthesized and processed to aqueous suspensions with high solid contents by a solvent displacement method followed by dialysis. The best suspension displayed a solid content of 16 wt.‐% and an average particle size of 108 nm. This suspension was mixed with a small amount of high molecular weight PEO and Brij78 and electrospun into corresponding nanofibers. After extraction with water, nanofibers of PHA‐b‐PEO were obtained. Electrospinning of aqueous suspensions of biodegradable polyesters alleviates concerns regarding safety, toxicology and environmental problems, which are associated with spinning of such polyesters from harmful organic solvents and thereby offers novel perspectives for applications in medicine, pharmacy and agriculture. Electrospinning of polymers from aqueous suspensions avoiding harmful organic solvents is suggested to be “green electrospinning”. magnified image
Anionic Synthesis and Rheological Characterization of Poly(p‐methylstyrene) Model Comb Architectures with a Defined and Very Low Degree of Long Chain Branching
Authors: Kempf Michael , Barroso Vitor C. , Wilhelm Manfred 
Published: October 2010

AbstractA method is presented for the synthesis of defined sparsely branched polystyrene‐based homopolymer model combs. By the use of poly(p‐methylstyrene) (PpMS) as backbone and side chains, a low, but well controlled amount of branching of typically less than 1 mol‐% (e.g., 1 branch per approx. 200 backbone C‐atoms) can be achieved. The used anionic synthesis offers full control of the molecular weight in combination with low polydispersity. Molecular weight and polydispersity were determined by SEC‐MALLS, confirming the well defined synthesis with low polydispersity ($\overline {{\rm M}} _{{\rm w}} /\overline {{\rm M}} _{{\rm n}} $ < 1.07). The melt rheological properties of the synthesized linear and comb polymers were obtained in both oscillatory shear and uniaxial extensional flow. Using the so‐called van Gurp–Palmen plot, clear differences between both synthesized topologies are clearly seen. The appearance of a second minimum for lower values of the complex modulus in shear is a clear indication of a second relaxation process attributable to the entangled side chains. The presence of the entangled side chains is responsible for the observed strain hardening obtained in extensional viscosity experiments, as compared to the linear polymers. These model samples open up the possibility to compare different advanced rheological methods, e.g., FT‐rheology or extensional rheology, towards limiting sensitivity. magnified image
Anisotropic Micro‐ and Nano‐Capsules
Authors: Shchepelina Olga , Kozlovskaya Veronika , Kharlampieva Eugenia , Mao Wenbin , Alexeev Alexander , Tsukruk Vladimir V. 
Published: October 2010

AbstractIn this work, we introduce anisotropically shaped, ultrathin micro‐ and nano‐capsules fabricated by layer‐by‐layer approach. The original cubic and tetrahedral shapes of the template particles were replicated to produce hollow capsules with well‐defined edges. Introducing tannic acid as a component of LbL shells resulted in enhanced chemical stability of these hollow polymer structures under a wide pH range due to high pKa value. Computational studies demonstrated increased mechanical stability of the anisotropic capsules under osmotic pressure variation due to sharp edges and vertices acting as a reinforcing frame in contrast to spherical microcapsules that undergo random buckling. magnified image
Interface microstructure of Stellite‐6 coatings on a 12%Cr steel after long term thermal exposure
Authors: Leinenbach C. , Al‐Badri A. , Roth M. 
Published: October 2010

Abstract9–12% Cr steels are widely used in turbine parts in steam power plants because of their good mechanical properties and corrosion resistance at elevated temperatures. However, parts like valve seats and spindles are prone to oxidation, particle erosion or wear. This requires the application of protective coatings with adequate mechanical properties, wear and spalling resistance. Cobalt based coatings like Stellite 6 are applied for service temperatures up to 550°C, but steam temperatures of up to 700°C are planned for future power plants in order to decrease the CO2 exhaustion. In this work, the interfacial microstructure of Stellite 6 coated 12% Cr steel before and after long term annealing at elevated temperatures (up to 625°C and 10 000 h) was characterized. The experimental results were compared with the results of additional thermodynamic simulations. It could be shown that a thin (˜20 μm), hard and brittle interlayer with a complex microstructure forms during annealing, which can affect the long term integrity of such components.9–12% Cr Stähle sind aufgrund ihrer guten mechanischen Eigenschaften und der relativ guten Korrosionsbeständigkeit bei erhöhten Temperaturen weitverbreitete Werkstoffe für Turbinenkomponenten in Dampfkraftwerken. Bestimmte Teile wie Ventilsitze oder ‐spindeln unterliegen einer ausgeprägten Beanspruchung verursacht durch Oxidation, Partikelerosion und Reibverschleiß. Aus diesem Grund werden häufig Schutzschichten mit angepassten mechanischen Eigenschaften, guten Verschleißeigenschaften sowie geringer Neigung zum Ablösen vom Grundwerkstoff eingesetzt. Beschichtungen aus Kobaltbasislegierungen wie z. B. Stellit 6 werden schon seit langen bei Betriebstemperaturen bis ca. 550°C verwendet. Für die Zukunft sind jedoch Frischdampftemperaturen von 700°C und mehr geplant, wodurch die CO2‐Emission von Kraftwerken reduziert werden soll. Im Rahmen dieser Arbeit wurde die grenzflächennahe Mikrostruktur von mit Stellit 6 beschichtetem 12%Cr‐Stahl vor und nach einer Langzeitauslagerung bis zu 10 000 h bei Temperaturen von bis zu 625°C charakterisiert. Die experimentellen Ergebnisse wurden mit den Ergebnissen ergänzender thermodynamischer Simulationen verglichen. Es konnte gezeigt werden, dass eine dünne (˜20 μm) harte und spröde Reaktionszwischenschicht mit komplexer Mikrostruktur während der Auslagerung entsteht, die sich negativ auf die Langzeitstabilität von entsprechenden Komponenten auswirken kann.
Very high cycle fatigue behavior of helical compression springs
Authors: Kaiser B. , Berger C. 
Published: October 2010

AbstractVorgestellt werden Vorgehensweise und Ergebnisse von Dauerschwingversuchen bis 109 Schwingspiele, die im Rahmen eines Forschungsvorhabens an zylindrischen Schraubendruckfedern mit zwei Drahtdurchmessern aus drei verschiedenen Werkstoffen vorgenommen wurden. Das Forschungsprojekt wurde zusammen mit einer Arbeitsgruppe des Verbands der Deutschen Federnindustrie (VDFi) initiiert und durchgeführt. Die Versuchsfedern wurden aus zwei ölschlussvergüteten SiCr‐ und SiCrV‐legierten Ventilfederstahldrähten und aus einem nichtrostenden Federstahldraht mit Drahtdurchmessern von 1,6 mm und 3,0 mm hergestellt und abschließend kugelgestrahlt. Die gebrochenen Federn wurden stereo‐ und rasterelektronenmikroskopisch sowie metallographisch untersucht, um das Bruchverhalten und die Schädigungsmechanismen zu analysieren. Die Versuchsfedern zeigen unterschiedliche Schwingfestigkeitseigenschaften und Versagensmechanismen im Bereich extrem hoher Schwingspielzahlen.This paper reports on procedure and research results of long‐term fatigue tests up to a number of 109 cycles on helical compression springs with two basic dimensions, made of three different spring materials. The corresponding research project was initiated together with a working group of the Association of German Springs' Industry (VDFi – Verband der Deutschen Federnindustrie). The test springs were manufactured of two oil hardened and tempered SiCr‐ and SiCrV‐alloyed valve spring steel wires and of one stainless steel wire with diameters of 1.6 mm and 3.0 mm and finally shot peened. Fractured test springs were investigated by stereo‐microscope, Scanning Electron Microscope (SEM) and by means of metallographic microsections in order to analyse the fracture behavior and the failure mechanisms. It becomes obvious that the various spring types in test exhibit different fatigue properties and also different failure mechanisms in the VHCF regime.
Investigating of polysulfide and epoxy‐polysulfide copolymer curing
Authors: Abdouss M. , Farajpour T. , Derakhshani M. 
Published: October 2010

AbstractPolysulfide can be cured in various methods. In this work, the effect of various oxidative curing agents (manganese dioxide and para quinonedioxime) in presence of curing accelerator (Diphenylguanidine) on mechanical‐dynamical properties and cure time of polysulfide resin (G4) was investigated. Results showed that mentioned oxidative curing agents have no remarkable effect on mechanical properties and cure time. But preferred method is preparation of polysulfide‐epoxy copolymer. This copolymer is a new class of liquid polymer composition containing block copolymers, with alternating blocks of polysulfide and polyepoxide. in different epoxy/polysulfide ratio, the epoxy‐polysulfide copolymer showd different tensile strenght, elongation, hardness, gel time, viscosity and Tg, but epoxy free polysulfide approximately revealed constant mechanical and dynamical properties so that epoxidized polysulfide had excellent mechanical properties and suitable curring times in comparison with those samples which were cured in other methods. FT‐IR spectroscopy, viscometry and GPC were used to verify the formation of epoxy‐polysulfide copolymer. Results obtained from DMTA and SEM showed that phase separation of epoxy resin from the copolymer matrix took place and The glass transition temperature (Tg) of the cured copolymer was between the cured epoxy and polysulfide glass transition temperatures.
Decreased striatal dopamine receptor binding in primary focal dystonia: A D2 or D3 defect?
Authors: Karimi Morvarid , Moerlein Stephen M. , Videen, Tom O. , Luedtke Robert R. , Taylor Michelle , Mach Robert H. , Perlmutter Joel S. 
Published: October 2010

AbstractDystonia is an involuntary movement disorder characterized by repetitive patterned or sustained muscle contractions causing twisting or abnormal postures. Several lines of evidence suggest that abnormalities of dopaminergic pathways contribute to the pathophysiology of dystonia. In particular, dysfunction of D2‐like receptors that mediate function of the indirect pathway in the basal ganglia may play a key role. We have demonstrated with positron emission tomography that patients with primary focal cranial or hand dystonia have reduced putamenal specific binding of [18F]spiperone, a nonselective D2‐like radioligand with nearly equal affinity for serotonergic 5‐HT(2A) sites. We then repeated the study with [18F]N‐methyl‐benperidol (NMB), a more selective D2‐like receptor radioligand with minimal affinity for 5‐HT(2A). Surprisingly, there was no decrease in NMB binding in the putamen of subjects with dystonia. Our findings excluded reductions of putamenal uptake greater than 20% with 95% confidence intervals. The analysis of the in vitro selectivity of NMB and spiperone demonstrated that NMB was highly selective for D2 receptors relative to D3 receptors (200‐fold difference in affinity), whereas spiperone has similar affinity for all three of the D2‐like receptor subtypes. These findings when coupled with other literature suggest that a defect in D3, rather than D2, receptor expression may be associated with primary focal dystonia. © 2010 Movement Disorder Society.
Apomorphine effect on pain threshold in Parkinson's disease: A clinical and positron emission tomography study
Authors: Dellapina Estelle , Gerdelat‐Mas Angélique , Ory‐Magne Fabienne , Pourcel Laure , Galitzky Monique , Calvas Fabienne , Simonetta‐Moreau Marion , Thalamas Claire , Payoux Pierre , Brefel‐Courbon Christine 
Published: October 2010

AbstractPatients with Parkinson's disease (PD) frequently experience pain that could be in part due to central modification of nociception. In this randomized controlled double blind study, we compared the effect of apomorphine versus placebo on pain thresholds and pain‐induced cerebral activity in 25 patients with PD. Subjective pain threshold (using thermal stimulation, thermotest), objective pain threshold (nociceptive flexion reflex), and cerebral activity (HO PET) during noxious and innocuous stimulations were performed. Neither subjective nor objective pain thresholds nor pain activation profile were modified by apomorphine compared with placebo in 25 PD patients. Apomorphine has no effect on pain processing in PD. We suggest that other monoamine systems than dopaminergic system could be involved. © 2010 Movement Disorder Society.
Exercise elevates dopamine D2 receptor in a mouse model of Parkinson's disease: In vivo imaging with [18F]fallypride
Authors: Vučcković Marta G. , Li Quanzheng , Fisher Beth , Nacca Angelo , Leahy Richard M. , Walsh John P. , Mukherjee Jogesh , Williams Celia , Jakowec Michael W. , Petzinger Giselle M. 
Published: October 2010

AbstractThe purpose of the current study was to examine changes in dopamine D2 receptor (DA‐D2R) expression within the basal ganglia of MPTP mice subjected to intensive treadmill exercise. Using Western immunoblotting analysis of synaptoneurosomes and in vivo positron emission tomography (PET) imaging employing the DA‐D2R specific ligand [18F]fallypride, we found that high intensity treadmill exercise led to an increase in striatal DA‐D2R expression that was most pronounced in MPTP compared to saline treated mice. Exercise‐induced changes in the DA‐D2R in the dopamine‐depleted basal ganglia are consistent with the potential role of this receptor in modulating medium spiny neurons (MSNs) function and behavioral recovery. Importantly, findings from this study support the rationale for using PET imaging with [18F]fallypride to examine DA‐D2R changes in individuals with Parkinson's Disease (PD) undergoing high‐intensity treadmill training. © 2010 Movement Disorder Society.