bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcriptional control of Rohon‐Beard sensory neuron development at the neural plate border
Authors: Rossi Christy Cortez , Kaji Takao , Artinger Kristin Bruk
Published: September 2009

Double in situ hybridization of a 2 somite zebrafish embryo stained with prdm1a (red) and sox19a (green) to reveal the neural plate border and neural plate respectively. Cover image collected with the help of C. Cave and advice from M. A. Wright in A. B. Ribera's lab. From Cortez‐Ross et al., Developmental Dynamics 238:931–943. © 2009 Wiley‐Liss, Inc.
Two New Helical Compounds Based on Pitch‐Tunable Keggin Clusters
Authors: Pang Hai‐jun , Zhang Chun‐jing , Peng Jun , Wang Yong‐hui , Sha Jing‐quan , Tian Ai‐xiang , Zhang Peng‐peng , Chen Yuan , Zhu Min , Su Zhong‐min
Published: September 2009

Two isostructural compounds, {[Cu2(DF)2H2O]2SiW12O40}·2H2O (1) and {[Cu2(DF)2H2O]2GeMo12O40}·2H2O (2) (DF = 4,5‐diazafluoren‐9‐one), were synthesized and characterized by routine methods and single‐crystal X‐ray diffraction. In the compounds, each Keggin cluster links five copper dimers [Cu2(DF)2H2O]2+ in an unusual asymmetrical pentacoordination mode to form 3D networks with left‐ and right‐handed helical chains. Notably, by comparing 1 and 2 with other helical compounds with Keggin clusters as connectors, we found that the pitches of those compounds are mainly dominated by the coordination modes of the Keggin clusters, suggesting that the Keggin clusters are pitch‐tunable synthons. Furthermore, the luminescent and electrochemical properties of the title compound were studied. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Trichocladinols A–C, Cytotoxic Metabolites from a Cordyceps‐Colonizing Ascomycete Trichocladium opacum
Authors: Guo Huijuan , Sun Bingda , Gao Hao , Niu Shubin , Liu Xingzhong , Yao Xinsheng , Che Yongsheng
Published: September 2009

Trichocladinols A–C (1–3), three new metabolites, and the known massarigenin A (4), have been isolated from cultures of a Cordyceps‐colonizing ascomycete Trichocladium opacum. Their structures were elucidated by NMR spectroscopy and X‐ray crystallography. The absolute configuration of 1 was assigned by using the modified Mosher method and that of 3 was determined by X‐ray crystallographic analysis of its (S)‐MTPA ester. Compounds 1–3 showed modest cytotoxic effects against the human tumor cell lines HeLa and MCF‐7. Structurally, compounds 1 and 2 possess a previously undescribed 2,9‐dioxatricyclo[5.2.1.03,8]dec‐4‐ene skeleton.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Supported Chiral Monodentate Ligands in Rhodium‐Catalysed Asymmetric Hydrogenation and Palladium‐Catalysed Asymmetric Allylic Alkylation
Authors: Swennenhuis Bert H. G. , Chen Ruifang , van Leeuwen Piet W. N. M. , de Vries Johannes G. , Kamer Paul C. J.
Published: September 2009

A family of monodentate polystyrene‐supported phosphites, phosphoramidites and phosphanes has been prepared and evaluated as ligands in rhodium‐catalysed asymmetric hydrogenation and palladium‐catalysed asymmetric allylic alkylation. The supported ligands yielded active and enantioselective catalysts, which in selected cases match the performance of the nonsupported counterparts. As expected, the performance of the supported ligands in the rhodium‐catalysed hydrogenation depends on the nature of the ligand, the type of polymeric support, as well as on the substrate. Additionally, the supported ligands have been applied in the monodentate ligand combination approach, by combining them with nonsupported monodentate ligands. The partially supported heteroligand combinations possess different catalytic properties than the related nonsupported combinations. The heteroligand species, however, are not formed selectively, and nonsupported homoleptic complexes also contribute to the overall activity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Gene expression analysis identifies over‐expression of CXCL1, SPARC, SPP1, and SULF1 in gastric cancer
Authors: Junnila Siina , Kokkola Arto , Mizuguchi Toru , Hirata Koichi , Karjalainen‐Lindsberg Marja‐Liisa , Puolakkainen Pauli , Monni Outi
Published: September 2009

To elucidate gene expression signatures associated with gastric carcinogenesis, we performed a genome‐wide expression analysis of 46 Finnish and 20 Japanese gastric tissues. Comparative analysis between Finnish and Japanese datasets identified 58 common genes that were differentially expressed between cancerous and non‐neoplastic gastric tissues. Twenty‐six of these genes were up‐regulated in cancer and 32 down‐regulated. Of these genes, 64% were also differentially expressed in another unrelated publicly available dataset. The expression levels of four of the up‐regulated genes, CXCL1, SPARC, SPP1 and SULF, were further analyzed in 82 gastric tissues using quantitative real‐time RT‐PCR. This analysis validated the results from the microarray analysis as the expression of these four genes was significantly higher in the cancerous tissue compared with the normal tissue (fold change 3.4–8.9). Over‐expression of CXCL1 also positively correlated with improved survival. To conclude, irrespective of the microarray platform or patient population, a common gastric cancer gene expression signature of 58 genes, including CXCL1, SPARC, SPP1, and SULF, was identified. These genes represent potential biomarkers for gastric cancer. © 2009 Wiley‐Liss, Inc.
The use of transient pressure analysis at the Dounreay Shaft Isolation Project
Authors: Pollard Rick , Jones Warren , Whitfield John
Published: September 2009

This paper provides an assessment of the use of pressure fall‐off data during the Dounreay Shaft Isolation Project. The instrumentation controlling the injection of grout monitors and records both the pressure and the flow rate throughout the process, so pressure fall‐off data is collected during any pauses to, and at the end of, each grout injection. The shapes of the pressure fall‐off vs time curves have been examined qualitatively and categorised. The fall‐off data has also been examined using PanSystem well test software, which creates the pressure change and pressure derivative curves, then attempts to simulate the fall‐off curve by iteration after selection of a flow and boundary model chosen from the wide range available. The implications that the shapes of the pressure and derivative curves and the flow and boundary models have for the grout curtain have been examined. The caveats that surround the quantitative use of results from Pan‐System analyses for a cement grout rather than a Newtonian fluid are discussed.

Diese Veröffentlichung handelt von der Beurteilung des Einsatzes und der Analyse von Daten zum Druckabfall im Zuge der Injektion am Schachtabdichtungsprojekt Dounreay, Schottland, UK. Die Instrumentation der Baustelle war darauf ausgelegt, Messwerte von Druck und Injektionsrate anzuzeigen, aufzuzeichnen und als Diagramm darzustellen. Damit war es möglich, in jeder Injektionsunterbrechung (also bei Rate = Null) und zu jedem Passenende Druckabfalldaten aufzuzeichnen. Die Form dieser Druckabfallkurven gegen die Zeit wurde qualitativ untersucht und kategorisiert. Eine weitere Interpretation dieser Daten erfolgte mittels des Programms “PanSystem”. Bei dieser Methodik werden die Druckänderungen über kleine Zeitinkremente errechnet und deren Ableitung über die Zeit in Kurvenform dargestellt. Durch iterative Simulation und Eingabe von Randbedingungen (“boundaries”) für das jeweilige Strömungsmodell – ausgewählt aus einer weiten Bandbreite von Möglichkeiten – ergibt sich die Möglichkeit, u. a. die Strömungsdimension, Strömungshindernisse und Reichweite der Injektion zu prognostizieren. Die daraus gezogenen Schlüsse für den Injektionsschirm wurden für die qualitative Abnahme der Arbeiten mitverwendet. In dem vorliegenden Artikel wird auch auf die möglichen Vorbehalte eingegangen, die sich aus den rheologischen Abweichungen von Injektionsmischungen gegenüber einer Newtonschen Flüssigkeit ergeben.
Notches formed by shear failures in tunnels (cherry pit mechanism) – advances in the progress of failure
Authors: Preh Alexander , Poisel Rainer
Published: September 2009

Rabcewicz was the first to describe the shear failure of cavities in rock (“Cherry pit mechanism”), which he observed in detail not only in tunnelling but also in mining and described into very advanced phases. He also developed an analytical model for this mechanism according to the limit equilibrium hypothesis, which permitted the estimation of the required support resistance. On the basis of model tests, Feder developed an extensive set of formulae for the process of failure. Using the finite difference code FLAC2D and the discrete element code PFC2D, the model presented by Rabcewicz and Feder has been developed further. It will be demonstrated that the process of failure can be split into two phases. In the late failure phase (large deformations), the mechanism observed in the mathematical model differs from the descriptions of Rabcewicz and Feder. While the break surfaces according to Rabcewicz and Feder form exclusively in the area near the cavity, break surfaces form in the mathematical model starting from the interstice of the side wall and extending far into the rock mass, and lead to the formation of trapezoidal regions in the crown and in the invert, which are pressed against each other.

Rabcewicz beschrieb als erster das Scherbruchversagen von Gebirgshohlräumen (“Cherry pit mechanism”), das er nicht nur im Tunnel‐ sondern auch im Bergbau eingehend beobachtete und bis in weit fortgeschrittene Phasen beschrieb. Für diesen Mechanismus entwickelte er auch ein analytisches Modell nach der Grenzgleichgewichtshypothese, das die Abschätzung von erforderlichen Ausbauwiderständen erlaubte. Auf der Basis von Modellversuchen entwickelte Feder einen umfangreichen Formelapparat für den Bruchablauf. Mithilfe des Finiten Differenzen Codes FLAC2D und des Diskreten Elemente Codes PFC2D wurden die Modellvorstellung von Rabcewicz und Feder weiterentwickelt. Es wird gezeigt, dass sich der Versagensablauf in zwei Phasen unterteilen lässt. In den späten Phasen des Versagens (große Verformungen) unterscheidet sich der in den numerischen Modellen beobachtete Mechanismus von den Beschreibungen von Rabcewicz und Feder. Während sich Bruchflächen bei Rabcewicz und Feder ausschließlich in den Nahbereichen des Hohlraums ausbilden, bilden sich in den numerischen Modellen Bruchflächen aus, die ausgehend von den Spitzen der Ulmenzwickel bis tief ins Gebirge reichen und zur Bildung von trapezförmigen Bereichen in der Firste und in der Sohle führen, die gegeneinander gedrückt werden.
Tunnel excavation material – high value raw material
Authors: Resch Daniel , Lassnig Klaus , Galler Robert , Ebner Fritz
Published: September 2009

A project called “Recycling of Tunnel Excavation Material” has been running since November 2008, supported by the Austrian Research Promotion Agency (FFG) and eminent Austrian client organisations and companies engaged in tunnelling and hydropower station construction, to investigate the possible recycling of tunnel excavation material at eleven selected Austrian tunnel and hydropower projects. This is intended to demonstrate economical and environmentally positive recycling. Test strategies are also to be developed for the evaluation of the reusability of tunnel excavation material from the point of view of construction management and economics, both for the individual projects and also relevant to the main lithologies likely to be encountered in Austrian tunnels.

Seit November 2008 wird in einem von der Forschungsförderungsgesellschaft (FFG) und namhaften Auftraggebern und Baufirmen des österreichischen Kraftwerks‐ und Tunnelbaus unterstützten Forschungsprojekt “Recycling von Tunnelausbruchmaterial” die mögliche Wiederverwertung von Ausbruchmaterial an elf ausgewählten österreichischen Tunnel‐ und Kraftwerksprojekten der Zukunft untersucht. Eine wirtschaftliche und umweltschonende Wiederverwertung soll nachgewiesen werden. Weiters werden für die einzelnen Projekte und die in Österreich bei Tunnelausbrüchen zu erwartenden Hauptlithologien Versuchsstrategien zur Beurteilung der Wiederverwendbarkeit von Tunnelausbruchmaterial aus baubetrieblicher und bauwirtschaftlicher Sicht ermittelt.
Concepts to overcome squeezing geological conditions at the Koralm tunnel
Authors: Wagner Hanns , Handke Dieter , Matter Jürg , Fabbri Davide , Keiper Knut
Published: September 2009

The Koralm tunnel forms the central part of the route of the Koralmbahn railway from Graz to Klagenfurt in the section Deutschlandsberg‐ St. Andrä. The tunnel, split into three construction contracts (KAT 1,2 and 3) connects the federal states of Carinthia and Styria in Austria with a length of 32.8 km. Continuous tunnelling is intended for the section through the central mountain complex of the Koralpe. The very variable geological conditions (rock and loose ground sections, overburden of up to approx. 1,200 m, possible high water pressures and pronounced zones of faulting and fracturing) represent a major challenge for the implementation of mechanical tunnelling (tunnelling, lining and logistics concepts). The present article discusses the geological and hydrogeological conditions as well as the basic concepts for support and machine system and the particular measures to overcome squeezing rock conditions.

Der Koralmtunnel bildet das zentrale Trassenstück der Koralmbahn Graz‐Klagenfurt im Abschnitt Deutschlandsberg‐St. Andrä. Der in drei Baulose (KAT 1, 2 und 3) gegliederte Tunnel verbindet auf einer Gesamtlänge von 32,8 km die Bundesländer Steiermark und Kärnten in Österreich. Für die Durchörterung des zentralen Gebirgskomplexes der Koralpe sind kontinuierliche Vortriebe vorgesehen. Die stark wechselnden geologischen Randbedingungen (Fest‐ und Lockergesteinsabschnitte, Überlagerungen bis ca. 1.200 m, mögliche hohe Wasserdrücke sowie ausgeprägte Störungs‐ und Zerrüttungszonen) stellen höchste Anforderungen an die Realisierung des Maschinenvortriebs (Vortriebs‐, Ausbauund Logistikkonzept). Im vorliegenden Beitrag werden die geotechnischen und hydrogeologischen Randbedingungen analysiert sowie die Grundkonzepte für Ausbausicherung und Maschinensystem und die besonderen Vorkehrungen zur Bewältigung der druckhaften Gebirgsverhältnisse vorgestellt.
S1 Danube‐Lobau tunnel – recycling of tunnel spoil material
Authors: Schröfelbauer Thomas , Schreitl Bernhard , Kitzler Christian
Published: September 2009

An important part of the S1 Vienna outer ring expressway is the tunnel under the Danube and Lobau with a length of 8.3 m. The ground to be tunnelled through is marked by Quaternary gravels and also by silt/clay with sand layers with low silt content. About 6 km are thus to be bored by two closed tunnel boring machines. A detailed material recycling plan for the entire S1 was produced for the processing of the excavation spoil. The excavated material was categorised according to its quality into various categories for appropriate recycling. The greatest possible free play for economic solutions has to be balanced with high requirements for the protection of people and the environment.

Ein wesentlicher Bestandteil der S1 Wiener Außenring Schnellstraße ist der Tunnel unter Donau und Lobau mit 8,3 km Länge. Der zu durchfahrende Untergrund ist gekennzeichnet durch quartäre Kiese einerseits und Schluff/Ton mit schluffarmen Sandschichten andererseits. Rund 6 km sollen daher in geschlossener Bauweise mit zwei Tunnelbohrmaschinen hergestellt werden. Zur Abwicklung der anfallenden Ausbruchmassen wurde ein detailliertes Massenverwertungskonzept für die gesamte S1 erstellt. Die anfallenden Massen wurden dazu nach ihrer Qualität in mehrere Kategorien eingeteilt, die einer entsprechenden Verwertung zugeführt werden. Größtmögliche Spielräume für wirtschaftliche Lösungen sind dabei mit den hohen Anforderungen an den Schutz von Mensch und Umwelt in Einklang zu bringen.
Comparing 3 T and 1.5 T MRI for tracking Alzheimer's disease progression with tensor‐based morphometry
Authors: Ho April J. , Hua Xue , Lee Suh , Leow Alex D. , Yanovsky Igor , Gutman Boris , Dinov Ivo D. , Leporé Natasha , Stein Jason L. , Toga Arthur W. , Jack Clifford R. , Bernstein Matt A. , Reiman Eric M. , Harvey Danielle J. , Kornak John , Schuff Norbert , Alexander Gene E. , Weiner Michael W. , Thompson Paul M. ,   the Alzheimer's Disease Neuroimaging Initiative
Published: September 2009

A key question in designing MRI‐based clinical trials is how the main magnetic field strength of the scanner affects the power to detect disease effects. In 110 subjects scanned longitudinally at both 3.0 and 1.5 T, including 24 patients with Alzheimer's Disease (AD) [74.8 ± 9.2 years, MMSE: 22.6 ± 2.0 at baseline], 51 individuals with mild cognitive impairment (MCI) [74.1 ± 8.0 years, MMSE: 26.6 ± 2.0], and 35 controls [75.9 ± 4.6 years, MMSE: 29.3 ± 0.8], we assessed whether higher‐field MR imaging offers higher or lower power to detect longitudinal changes in the brain, using tensor‐based morphometry (TBM) to reveal the location of progressive atrophy. As expected, at both field strengths, progressive atrophy was widespread in AD and more spatially restricted in MCI. Power analysis revealed that, to detect a 25% slowing of atrophy (with 80% power), 37 AD and 108 MCI subjects would be needed at 1.5 T versus 49 AD and 166 MCI subjects at 3 T; however, the increased power at 1.5 T was not statistically significant (α = 0.05) either for TBM, or for SIENA, a related method for computing volume loss rates. Analysis of cumulative distribution functions and false discovery rates showed that, at both field strengths, temporal lobe atrophy rates were correlated with interval decline in Alzheimer's Disease Assessment Scale‐cognitive subscale (ADAS‐cog), mini‐mental status exam (MMSE), and Clinical Dementia Rating sum‐of‐boxes (CDR‐SB) scores. Overall, 1.5 and 3 T scans did not significantly differ in their power to detect neurodegenerative changes over a year. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Evidence for modulation of opioidergic activity in central vestibular processing: A [18F] diprenorphine PET study
Authors: Baier Bernhard , Bense Sandra , Birklein Frank , Buchholz Hans‐Georg , Mischke Anja , Schreckenberger Matthias , Dieterich Marianne
Published: September 2009

Animal and functional imaging studies had identified cortical structures such as the parieto‐insular vestibular cortex, the retro‐insular cortex, or the anterior cingulate cortex belonging to a vestibular cortical network. Basic animal studies revealed that endorphins might be important transmitters involved in cerebral vestibular processing. The aim of the present study was therefore to analyse whether the opioid system is involved in vestibular neurotransmission of humans or not. Changes in opioid receptor availability during caloric air stimulation of the right ear were studied with [18F] Fluoroethyl‐diprenorphine ([18F]FEDPN) PET scans in 10 right‐handed healthy volunteers and compared to a control condition. Decrease in receptor availability to [18F]FEDPN during vestibular stimulation in comparison to the control condition was significant at the right posterior insular cortex and the postcentral region indicating more endogenous opioidergic binding in these regions during stimulation. These data give evidence that the opioidergic system plays a role in the right hemispheric dominance of the vestibular cortical system in right‐handers. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Respiratory–swallow phase patterns and their relationship to swallowing impairment in patients treated for oropharyngeal cancer
Authors: Brodsky Martin B. , McFarland David H. , Dozier Thomas S. , Blair Julie , Ayers Christopher , Michel Yvonne , Gillespie M. Boyd , Day Terry A. , Martin‐Harris Bonnie
Published: September 2009

Background.

Unstable respiratory–swallowing coordination has been associated with disorders and disease. The goals of this study were (1) to describe respiratory–swallow patterns in patients with dysphagia consequent to treatments for cancers of the oropharynx and (2) to determine the association between respiratory–swallow patterns, airway invasion, and overall severity of swallowing impairment.

Methods.

This prospective, cross‐sectional design compared respiratory–swallow patterns in 20 patients treated for oropharyngeal cancer and 20 healthy, age‐matched control participants. Nasal airflow direction was synchronously recorded with videofluoroscopic imaging in participants who swallowed 5‐mL thin liquid barium boluses.

Results.

Respiratory–swallow patterns differed between groups. Most control participants initiated and completed swallowing bracketed by expiratory airflow. Swallowing in patients often interrupted inspiratory flow and was associated with penetration or aspiration of the bolus.

Conclusions.

We suggest nonexpiratory bracketed respiratory–swallowing phase patterns in patients with oropharyngeal cancer may place patients at greater risk of airway penetration or aspiration during swallowing. © 2009 Wiley Periodicals, Inc. Head Neck, 2010
Globular adiponectin inhibits angiotensin II‐induced nuclear factor κB activation through AMP‐activated protein kinase in cardiac hypertrophy
Authors: Wang Cheng , Li Li , Zhang Zhi‐Guo , Fan Dong , Zhu Yi , Wu Li‐Ling
Published: September 2009

Activation of nuclear factor κB (NF‐κB) has been found necessary for cardiac hypertrophic growth in vivo and in vitro experiments. Adiponectin, an adipocyte‐derived polypeptide, suppresses cardiac hypertrophy in response to pressure overload. Here we investigated the potential effect of adiponectin on NF‐κB activation in hypertrophic neonatal rat ventricular myocytes (NRVMs) and related signal transduction pathway. We treated NRVMs with globular adiponectin (gAd) before angiotensin II (AngII) stimulation. Pretreating cells with gAd reduced the increased incorporation of [3H]‐leucine and the mRNA levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) stimulated by AngII, indicating gAd inhibited AngII‐induced cardiac hypertrophic signaling. Moreover, gAd pretreatment suppressed inhibitory protein κB (I‐κB) phosphorylation and decreased p65 nuclear translocation, DNA‐binding and transcription activity of NF‐κB. Meanwhile, gAd promoted AMP‐activated protein kinase (AMPK) phosphorylation, which is a downstream signaling mediator of adiponectin. Pharmacological activator of AMPK could inhibit AngII‐induced NF‐κB translocation, and inhibitor of AMPK or a dominant‐negative AMPK adenovirus suppressed gAd‐mediated inhibition of I‐κB phosphorylation and NF‐κB activation. When AMPK was inhibited, the suppressive effect of gAd on ANP mRNA expression was reduced. Our data indicate that gAd inhibits cardiac hypertrophic signaling through AMPK mediated suppression of NF‐κB activation. J. Cell. Physiol. 222:149–155, 2010. © 2009 Wiley‐Liss, Inc.
Calcium‐stimulated mitogen‐activated protein kinase activation elicits Bcl‐xL downregulation and Bak upregulation in notexin‐treated human neuroblastoma SK‐N‐SH cells
Authors: Chen Ku‐Chung , Liu Wen‐Hsin , Kao Pei‐Hsiu , Chang Long‐Sen
Published: September 2009

Notechis scutatus scutatus notexin induced apoptotic death of SK‐N‐SH cells accompanied with downregulation of Bcl‐xL, upregulation of Bak, mitochondrial depolarization, and ROS generation. Upon exposure to notexin, Ca2+‐mediated JNK and p38 MAPK activation were observed in SK‐N‐SH cells. Production of ROS was a downstream event followed by Ca2+‐mediated mitochondrial alteration. Notexin‐induced cell death, mitochondrial depolarization, and ROS generation were suppressed by SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor). Moreover, phospho‐p38 MAPK and phospho‐JNK were proved to be involved in Bcl‐xL degradation, and overexpression of Bcl‐xL attenuated the cytotoxic effect of notexin. Bak upregulation was elicited by p38 MAPK‐mediated ATF‐2 activation and JNK‐mediated c‐Jun activation. Suppression of Bak upregulation by ATF‐2 siRNA or c‐Jun siRNA attenuated notexin‐evoked mitochondrial depolarization and rescued viability of notexin‐treated cells. Taken together, our data indicate that notexin‐induced apoptotic death of SK‐N‐SH cells is mediated through mitochondrial alteration triggering by Ca2+‐evoked p38 MAPK/ATF‐2 and JNK/c‐Jun signaling pathways. J. Cell. Physiol. 222:177–186, 2010. © 2009 Wiley‐Liss, Inc.
Generation of neural crest progenitors from human embryonic stem cells
Authors: Chimge Nyam‐Osor , Bayarsaihan Dashzeveg
Published: September 2009

The neural crest (NC) is a transient population of multipotent progenitors arising at the lateral edge of the neural plate in vertebrate embryos, which then migrate throughout the body to generate diverse array of tissues such as the peripheral nervous system, skin melanocytes, and craniofacial cartilage, bone and teeth. The transient nature of neural crest stem cells make extremely challenging to study the biology of these important cells. In humans induction and differentiation of embryonic NC occurs very early, within a few weeks of fertilization giving rise to technical and ethical issues surrounding isolation of early embryonic tissues and therefore severely limiting the study of human NC cells. For that reason our current knowledge of the biology of NC mostly derives from the studies of lower organisms. Recent progress in human embryonic stem cell research provides a unique opportunity for generation of a useful source of cells for basic developmental studies. The development of cost‐effective, time and labor efficient improved differentiation protocols for the production of human NC cells is a critical step toward a better understanding of NC biology. J. Exp. Zool. (Mol. Dev. Evol.) 314B:95–103, 2010. © 2009 Wiley‐Liss, Inc.
Improvements in carotid plaque imaging using a new eight‐element phased array coil at 3T
Authors: Balu Niranjan , Yarnykh Vasily L. , Scholnick Joshua , Chu Baocheng , Yuan Chun , Hayes Cecil
Published: September 2009

Purpose

To design and compare an eight‐channel phased array (PA) coil for carotid imaging to an established four‐channel PA design at 3T.

Materials and Methods

An eight‐channel PA (8PA) coil was designed specifically for imaging the carotid bifurcation and compared with the existing four‐channel (4PA) design using a phantom and by in vivo black‐blood magnetic resonance imaging (MRI). The 8PA and 4PA were compared in terms of coverage, signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR).

Results

The 8PA showed up to 1.7‐fold improvement in SNR at a depth of 3.5 cm and greater longitudinal coverage at a given SNR on a phantom. The 8PA showed improved vessel wall SNR for high spatial resolution (0.63 mm2) PD, T1, and T2 (1.7, 1.7, 1.6 times, respectively; P ≤ 0.002) and improved CNR (1.7, 1.6, 1.5 times, respectively; P ≤ 0.002). Ultrahigh‐resolution (0.27 mm2) T1‐weighted images showed better SNR and CNR (1.4 times, P ≤ 0.0001) on 8PA compared to 4PA.

Conclusion

Carotid imaging studies may benefit from the improved SNR and larger coverage provided by use of the 8PA. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Assessment of lipids in skeletal muscle by LCModel and AMARES
Authors: Weis Jan , Johansson Lars , Ortiz‐Nieto Francisco , Ahlström Håkan
Published: September 2009

Purpose

To process single voxel spectra of the human skeletal muscle by using an advanced method for accurate, robust, and efficient spectral fitting (AMARES) and by linear combination of model spectra (LCModel). To determine absolute concentrations of extra‐ (EMCL) and intramyocellular lipids (IMCL).

Materials and Methods

Single‐voxel proton magnetic resonance spectroscopy (PRESS) was used to obtain the spectra of the calf muscles. Unsuppressed water line was used as a concentration reference. A new prior knowledge for AMARES was proposed to estimate the concentrations of EMCL and IMCL. The prior knowledge was derived from the spectrum of vegetable oil. The results were compared with the values estimated by LCModel. Absolute concentrations of total lipid content in millimoles per kilogram wet weight were used for the comparisons.

Results

Absolute concentrations of total lipid content in skeletal muscle were estimated by AMARES and LCModel. Very good correlation of the total fat (EMCL + IMCL) and IMCL concentrations was achieved between both data processing approaches.

Conclusion

Assessment the absolute concentrations of muscular lipids by AMARES and LCModel can be performed with comparable accuracy. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Quantitative assessment of myocardial T2 relaxation times in cardiac amyloidosis
Authors: Sparrow Patrick , Amirabadi Afsaneh , Sussman Marshall S. , Paul Narinder , Merchant Naeem
Published: September 2009

Purpose

To evaluate cardiac MRI (CMR) in the diagnosis of cardiac amyloidosis by comparing the T2 relaxation times of left ventricular myocardium in a pilot patient group to a normal range established in healthy controls.

Materials and Methods

Forty‐nine patients with suspected amyloidosis‐related cardiomyopathy underwent comprehensive CMR examination, which included assessment of myocardial T2 relaxation times, ventricular function, resting myocardial perfusion, and late gadolinium enhancement (LGE) imaging. T2‐weighted basal, mid, and apical left ventricular slices were acquired in each patient using a multislice T2 magnetization preparation spiral sequence. Slice averaged T2 relaxation times were subsequently calculated offline and compared to the previously established normal range.

Results

Twelve of the 49 patients were confirmed to have cardiac amyloidosis by biopsy. There was no difference in mean T2 relaxation times between the amyloid cases and normal controls (51.3 ± 8.1 vs. 52.1 ± 3.1 msec, P = 0.63). Eleven of the 12 amyloid patients had abnormal findings by CMR, eight having LGE involving either ventricles or atria and four demonstrating resting subendocardial perfusion defects.

Conclusion

CMR is a potentially valuable tool in the diagnosis of cardiac amyloidosis. However, calculation of myocardial T2 relaxation times does not appear useful in distinguishing areas of amyloid deposition from normal myocardium. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.
Chemical characterisation of Nephrops norvegicus from Portuguese coast
Authors: Lourenço Helena M , Anacleto Patrícia , Afonso Cláudia , Martins Maria F , Carvalho Maria L , Lino Ana R , Nunes Maria L
Published: September 2009

BACKGROUND: Among seafood products, crustaceans are an important group owing to their nutritional benefits and high market value. The aim of this study was to evaluate the proximate composition as well as essential and non‐essential elements in the edible muscle of Nephrops norvegicus (Norway lobster).

RESULTS: The studied crustacean showed a high protein level of about 210 g kg−1 and a mineral level of about 24 g kg−1. The pattern for the elements studied was Cl > Na > K > P > S > Ca > Mg > Br > Fe > Sr ≈ Zn > Cu > Mn > Rb > Se > Ni > Cr. Regarding non‐essential elements, the average total Hg content was 0.40 mg kg−1, but two samples exceeded the legal limit set by the European Union (EU) for Hg in crustaceans (0.50 mg kg−1). The levels of Pb and Cd found in all samples were below the EU limits (0.50 mg kg−1 for both metals).

CONCLUSION: Nephrops norvegicus is a good source of protein and contains most minerals at levels sufficient to satisfy the dietary reference intake. The amounts of Pb and Cd are not a concern. Hg levels indicate some contamination; however, taking into account the type of consumption of this species, it can be concluded that this does not represent a risk in terms of the human diet. Copyright © 2009 Society of Chemical Industry
Association of a functional polymorphism of PTPN22 encoding a lymphoid protein phosphatase in bilateral Meniere's disease
Authors: Lopez‐Escamez Jose A. , Saenz‐Lopez Pablo , Acosta Lourdes , Moreno Antonia , Gazquez Irene , Perez‐Garrigues Herminio , Lopez‐Nevot Alicia , Lopez‐Nevot Miguel A.
Published: September 2009

Objectives/Hypothesis:

Bilateral Meniere's disease (BMD) is a severe disease that usually results in bilateral severe or profound sensorineural hearing loss and chronic disequilibrium with loss of vestibular function. We examined single nucleotide polymorphisms (SNPs) in the PTPN22 and CTLA4 genes in Caucasian patients with BMD to assess the possible association between these polymorphism and the predisposition and clinical expression of this disease.

Study Design:

A case control study.

Methods:

The functional protein tyrosine phosphatase type 22 (PTPN22) SNP (rs2476601, 1858C/T) and CTLA4 SNP (rs231775, 49A/G) were analyzed in 52 patients with BMD and 348 healthy controls by a TaqMan 5′ allelic discrimination assay. Data were analyzed by a χ2 test with Fisher exact test.

Results:

No association was found between the +49A/G CTLA4 genotype and BMD patients. However, the heterozygote PTPN22 1858C/T genotype was present at a significantly higher frequency in BMD patients than in controls (odds ratio = 2.25, 95% confidence interval: 1.09–4.62; P = .04).

Conclusions:

These results suggest that the PTPN22 1858C/T genotype may confer differential susceptibility to BMD in the Spanish population and support an autoimmune etiology for BMD. Laryngoscope, 2010
Long‐term outcomes from the English national comparative audit of surgery for nasal polyposis and chronic rhinosinusitis
Authors: Hopkins Claire , Slack Robert , Lund Valerie , Brown Peter , Copley Lynn , Browne John
Published: September 2009

Objectives/Hypothesis:

We present a large, prospective cohort study following patients who underwent surgery for chronic rhinosinusitis (CRS), with or without nasal polyps, in hospitals in England and Wales. Five‐year outcomes will be reported, and we will revisit a previous analysis of the effectiveness of extensive surgery in the treatment of nasal polyposis.

Methods:

Baseline clinical data was collected for 3,128 patients undergoing surgery for CRS (with or without nasal polyps). Outcomes are described in terms of the proportion of patients undergoing revision surgery and mean Sino‐Nasal Outcome Test (SNOT‐22) scores.

Results:

A total of 1,459 (52.2%) patients responded to 5‐year follow‐up. Revision surgery rates increased at each time point. Of the patients responding, 279 patients (19.1%) had undergone further surgery during the 5 years since their original operation. Of the patients with polyps, 20.6% had undergone revision compared to 15.5% of patients with CRS alone. The mean SNOT‐22 score for all patients was 28.2 (standard deviation [SD] = 22.4) at 5 years after surgery. This is remarkably similar to the results observed at 3 months (25.5), 12 months (27.7), and 36 months (27.7), and represents a 14‐point improvement over the baseline score. Polyp patients report better SNOT‐22 scores at 5 years (mean = 26.2; SD = 21.6) than patients with CRS alone (mean = 33.3; SD = 23.7). Of the patients who had originally received simple polypectomy, 21.2% had undergone revision surgery compared to 20.0% of patients who had also received additional sinus surgery. The difference in unadjusted revision surgery rates is not statistically significant (χ2 = 0.22; P = .64). However, the difference becomes statistically significant when a multivariate logistic regression is used to adjust for baseline characteristics, with patients undergoing additional sinus surgery being less likely to undergo further surgery within the study period (adjusted odds ratio = 0.66; P = .04).

Conclusions:

We have shown sinonasal surgery to be safe and effective in reducing the symptoms associated with CRS over a 5‐year period. The reduction in symptoms is large, with no significant decline in symptomatic improvement from 12 to 60 months postsurgery. However, revision surgery rates approach 20% over this time, and patients should be counseled accordingly prior to surgery. Laryngoscope, 2009
Reciprocative sliding friction and wear properties of electrical discharge machined ZrO2‐based composites
Authors: Bonny Koenraad , De Baets Patrick , Samyn Pieter , Lobbestael Filip , Vleugels Jozef , Lauwers Bert , Liu Weidong
Published: September 2009

Hot‐pressed, laboratory‐made, ZrO2‐based composites with 40 vol. % WC, TiCN or TiN were surface finished by electrical discharge machining in order to compare their reciprocating sliding friction and wear response against WC–6wt%Co cemented carbide in unlubricated conditions. Sliding experiments were performed using a Plint TE77 pin‐on‐flat wear test rig, revealing a strong impact of the secondary phase on the tribological behaviour of the ZrO2‐based composites. The worn surfaces and wear debris were characterised by scanning electron microscopy, energy dispersive X‐ray analysis and surface topography scanning, pointing out abrasion, polishing and adhesion as main wear mechanisms. The most favourable friction and wear characteristics were encountered with ZrO2–WC composites compared to the other grades with equal amount of volumetric secondary phase. Copyright © 2009 John Wiley & Sons, Ltd.
Observation of lubrication conditions using an ultrasonic technique
Authors: Takeuchi A.
Published: September 2009

Evaluation of lubrication conditions for a real frictional surface, such as a steel bearing, becomes an important issue for safe operation of a machine. In this paper, an application of ultrasonic technique is attempted for a purpose of evaluating the lubrication conditions. Ultrasonic waves emitted towards a hydrodynamic lubrication interface are reflected multiple times in oil film, and an echo height of reflected waves from the boundary is dependent on film thickness. The results of this study indicated that the ultrasonic technique is able to measure film thickness of approximately 50 nm in the case of a standstill surface having extremely small surface roughness. Furthermore, a potential for estimating the oil film thickness between a piston ring and cylinder is also indicated. In addition, in the case of a ball bearing, quantitative measurement of a size of dent, which forms the origin of flaking, is important for an evaluation of lubrication conditions. This becomes possible with an observation of a change in the echo height reflected from a boundary surface between a housing and an outer ring of the ball bearing. In this study, quantitative measurement of an indentation having 0.32 mm width on a raceway surface of an inner ring was achieved. Copyright © 2009 John Wiley & Sons, Ltd.
Poly(N‐isopropylacrylamide) Brush Fabricated by Surface‐Initiated Photopolymerization and its Response to Temperature
Authors: Jia Xinyan , Jiang Xuesong , Liu Rui , Yin Jie
Published: September 2009

A well‐defined, high‐density poly(N‐isopropylacrylamide) (PNIPAM) brush was fabricated through a novel and reliable strategy by the combination of the self‐assembly of a monolayer of dendritic photoinitiator and surface‐initiated photopolymerization. The whole fabrication process of the PNIPAM brush was followed by water contact angles, X‐ray photoelectron spectroscopy, and atomic force microscopy. Characterization of the PNIPAM brush, such as molecular weight and thickness determination, were measured by gel permeation chromatography, and ellipsometry, and the graft density was estimated. The temperature response of the PNIPAM brush was further investigated and the result verified the coil‐to‐globule transition of the PNIPAM chains in water from low to high temperature.

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A Novel Type of Vesicles Based on Ionic and π–π Interactions
Authors: Gröhn Franziska , Klein Katja , Koynov Kaloian
Published: September 2009

Electrostatic self‐assembly can be used to form supramolecular vesicles in aqueous solution. Vesicles consist of cationic G8 poly(amidoamine) dendrimers and the trivalent sulfonate dye Ar27. No classical amphiphiles are present but the interplay of electrostatics, π–π interaction and geometric factors influences the structure formation. Labeled guest molecules, both small molecules and peptides, can be included inside these vesicles and vesicles imaged by fluorescence techniques. The structure was studied by dynamic and static light scattering, small‐angle neutron scattering, confocal laser scanning microscopy, and fluorescence correlation spectroscopy. The study indicates the prospect of constructing functional nanoobjects by the self‐assembly of charged molecules in aqueous solution.

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Single‐Step Electrospinning of Bimodal Fiber Meshes for Ease of Cellular Infiltration
Authors: Gentsch Rafael , Boysen Bjoern , Lankenau Andreas , Börner Hans G.
Published: September 2009

Bimodal fiber meshes with fiber diameters differing by one order of magnitude, are electrospun in a simple one‐step process, using a standard single syringe electrospin setup. The nano‐ and microfiber meshes combine the benefits of nanofibers (cell adhesion, proliferation) with those of microfibers (open structure, large pore size) and are therefore interesting as scaffolds for cellular infiltration.

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Effect of Solvent Molecular Size on the Self‐Assembly of Amphiphilic Diblock Copolymer in Selective Solvent
Authors: Li Wei , Jiang Wei
Published: September 2009

Real‐space self‐consistent field theory (SCFT) is employed to study the effect of solvent molecular size on the self‐assembly of amphiphilic diblock copolymer in selective solvent. The phase diagrams in wide ranges of interaction parameters and solvent molecular size were obtained in present study. The results indicate that the solvent molecular size is a key factor that determines the self‐assembly of amphiphilic diblock copolymer. The self‐assembled morphology changes from circle‐like micelle to line‐like micelle, then to loop‐like micelle by decreasing the solvent molecular size in a wide range of solvent selectivity. We analyze and discuss this change in terms of the solvent solubility and the entropy contribution.

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Hyperpolarized 13C magnetic resonance detection of carboxypeptidase G2 activity
Authors: Jamin Yann , Gabellieri Cristina , Smyth Lynette , Reynolds Steven , Robinson Simon P. , Springer Caroline J. , Leach Martin O. , Payne Geoffrey S. , Eykyn Thomas R.
Published: September 2009

Carboxypeptidase G2 (CPG2) is a bacterial enzyme that is currently employed in a range of targeted cancer chemotherapy strategies such as gene‐directed enzyme prodrug therapy (GDEPT). Employing dynamic nuclear polarization (DNP) and natural abundance 13C magnetic resonance spectroscopy (MRS), we observed the CPG2‐mediated conversion of a novel hyperpolarized reporter probe 3,5‐difluorobenzoyl‐L‐glutamic acid (3,5‐DFBGlu) to 3,5‐difluorobenzoic acid (3,5‐DFBA) and L‐glutamic acid (L‐Glu) in vitro. Isotopic labeling of the relevant nuclei with 13C in 3,5‐DFBGlu or related substrates will yield a further factor of 100 increase in the signal‐to‐noise. We discuss the feasibility of translating these experiments to generate metabolic images of CPG2 activity in vivo. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Assessment of intervertebral disc degeneration with magnetic resonance single‐voxel spectroscopy
Authors: Zuo Jin , Saadat Ehsan , Romero Adan , Loo Kimberly , Li Xiaojuan , Link Thomas M. , Kurhanewicz John , Majumdar Sharmila
Published: September 2009

This study examined the feasibility of using short‐echo water‐suppressed point‐resolved spectroscopy (PRESS) on a clinical 3T magnetic resonance (MR) scanner for evaluating biochemical changes in degenerated bovine and cadaveric human intervertebral discs. In bovine discs (N = 17), degeneration was induced with papain injections. Degeneration of human cadaveric discs (N = 27) was assessed using the Pfirrmann grading on T2‐weighted images. Chemicals in the carbohydrate region (Carb), the choline head group (Cho), the N‐acetyl region (N‐acetyl), and the lipid and lactate region (Lac+Lip) were quantified using 1H PRESS, and were compared between specimens with different degrees of degeneration. The correlation between the spectroscopic findings and glycosaminoglycan (GAG) quantification using biochemical assays was determined. Significant differences were found between the ratios (N‐acetyl/Cho, N‐acetyl/Lac+Lip) acquired before and after papain injection in bovine discs. For human cadaveric discs, significant differences in the ratios (N‐acetyl/Carb, N‐acetyl/Lac+Lip) were found between discs having high and low Pfirrmann scores. Significant correlations were found between N‐acetyl/Lac+Lip and GAG content in bovine discs (R = 0.77, P = 0.0007) and cadaveric discs (R = 0.83, P < 0.0001). Significant correlation between N‐acetyl/Cho and GAG content was also found in cadaver discs (R = 0.64, P = 0.0039). This study demonstrates for the first time that short‐echo PRESS on a clinical 3T MR scanner can be used to noninvasively and can reproducibly quantify metabolic changes associated with degeneration of intervertebral discs. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Measurement of glycine in human prefrontal brain by point‐resolved spectroscopy at 7.0 tesla in vivo
Authors: Choi Changho , Douglas Deborah , Hawesa Halima , Jindal Ashish , Storey Charles , Dimitrov Ivan
Published: September 2009

Measurement of glycine in human frontal brain by an optimized point‐resolved spectroscopy sequence at 7 T is reported. Echo time dependencies of the overlapping coupled resonances of myo‐inositol, free choline, and threonine were investigated with density matrix simulations, incorporating the slice‐selective radiofrequency and gradient pulses. The numerical simulations indicated that the selectivity of the 3.55‐ppm glycine singlet is maximized at (TE1, TE2) = (101, 51) ms. Phantom experiments indicated that the myo‐inositol peak amplitude between 3.5 and 3.6 ppm is reduced by a factor of 30 following the optimized point‐resolved spectroscopy, as predicted by the simulation. From LCModel analyses, the glycine concentration in the medial prefrontal cortex in healthy adults was estimated, with a mean Cramér‐Rao lower bound of 7 ± 1% (mean ± standard deviation; n = 7), to be 0.8 ± 0.1 mM, with reference to total creatine at 8 mM. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
In vivo assessments of mucus dynamics in the rat lung using a Gd‐Cy5.5‐bilabeled contrast agent for magnetic resonance and optical imaging
Authors: Blé François‐Xavier , Schmidt Philipp , Cannet Catherine , Kneuer Rainer , Karmouty‐Quintana Harry , Bergmann Reinhard , Coote Kevin , Danahay Henry , Zurbruegg Stefan , Gremlich Hans‐Ulrich , Beckmann Nicolau
Published: September 2009

Dysfunctions in mucociliary clearance are associated with the accelerated loss of lung function in several respiratory diseases. Approaches enabling the in vivo visualization of mucus dynamics in rodents at high resolution and sensitivity would be beneficial for experimental lung research. We describe the synthesis and characterization of two bilabeled amino dextran–based probes binding specifically to mucin. Labeling of secreted mucus and of mucin in goblet cells in the lungs of lipopolysaccharide‐challenged rats has been demonstrated in vivo with near‐infrared fluorescence and MRI and confirmed by histology. The effects of uridine triphosphate were then studied in lipopolysaccharide‐challenged rats by simultaneously administering the imaging probe and the compound. The data suggest that uridine triphosphate increased the mucociliary clearance, but at the same time induced a release of mucin from goblet cells, thus not contributing to the overall reduction of mucus in the lung. The approach outlined here enables one to derive information on mucus clearance, as well as secretion. Such a global view on mucus dynamics may prove invaluable when testing new pharmacological agents aimed at improving mucociliary clearance. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.