bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synaptic localization of neuroligin 2 in the rodent retina: Comparative study with the dystroglycan‐containing complex
Authors: Lui Leona , Levinson Joshua N. , Noël Geoffroy , Handrigan Gregory R. , Richman Joy M. , El‐Husseini Alaa , Moukhles Hakima 
Published: October 2009

AbstractSeveral recent studies have shown that neuroligin 2 (NL2), a component of the cell adhesion neurexins–neuroligins complex, is localized postsynaptically at hippocampal and other inhibitory synapses throughout the brain. Other studies have shown that components of the dystroglycan complex are also localized at a subset of inhibitory synapses and are coexpressed with NL2 in brain. These data prompted us to undertake a comparative study between the localization of NL2 and the dystroglycan complex in the rodent retina. First, we determined that NL2 mRNA is expressed both in the inner and in the outer nuclear layers. Second, we found that NL2 is localized both in the inner and in the outer synaptic plexiform layers. In the latter, the horseshoe‐shaped pattern of NL2 and its extensive colocalization with RIM2, a component of the presynaptic active zone at ribbon synapses, argue that NL2 is localized presynaptically at photoreceptor terminals. Third, comparison of NL2 and the dystroglycan complex distribution patterns reveals that, despite their coexpression in the outer plexiform layer, they are spatially segregated within distinct domains of the photoreceptor terminals, where NL2 is selectively associated with the active zone and the dystroglycan complex is distally distributed in the lateral regions. Finally, we report that the dystroglycan deficiency in the mdx3cv mouse does not alter NL2 localization in the outer plexiform layer. These data show that the NL2‐ and dystroglycan‐containing complexes are differentially localized in the presynaptic photoreceptor terminals and suggest that they may serve distinct functions in retina. © 2009 Wiley‐Liss, Inc.
DHA diet reduces AD pathology in young APPswe/PS1ΔE9 transgenic mice: Possible gender effects
Authors: Perez Sylvia E. , Berg Brian M. , Moore Kenneth A. , He Bin , Counts Scott E. , Fritz Jason J. , Hu Yuan‐Shih , Lazarov Orly , Lah James J. , Mufson Elliott J. 
Published: October 2009

AbstractEpidemiological and clinical trial findings suggest that consumption of docosahexaenoic acid (DHA) lowers the risk of Alzhemier's disease (AD). We examined the effects of short‐term (3 months) DHA enriched diet on plaque deposition and synaptic deficts in forebrain of young APPswe/PS1ΔE9 transgenic (tg) and non‐transgenic (ntg) mice. Gas chromatography revealed a significant increase in DHA concomitant with a decrease of arachidonic acid in both brain and liver in mice fed with DHA. Female tg mice consumed relatively more food daily than ntg female mice, independent of diet. Plaque load was significantly reduced in the cortex, ventral hippocampus and striatum of female APPswe/PS1ΔE9 tg mice on DHA diet compared to female tg mice on control diet. Immunoblot quantitation of the APOE receptor, LR11, which is involved in APP trafficking and Aβ production, were unchanged in mice on DHA or control diets. Moreover drebrin levels were significantly increased in the hippocampus of tg mice on the DHA diet. Finally, in vitro DHA treatment prevented amyloid toxicity in cell cultures. Our findings support the concept that increased DHA consumption may play and important role in reducing brain insults in female AD patients. © 2009 Wiley‐Liss, Inc.
Qualitätskontrolle bei Laserschweißnähten
Authors: Döttinger Christoph 
Published: October 2009

AbstractIm Eiltempo hat das Laserschweißen als Innovatives Fügeverfahren einen festen Platz in der Automobilindustrie erobert. Adäquate Methoden zur Qualitätskontrolle und Fehlerdiagnose konnten hier nur schwer Schritt halten. Abhilfe schaffen kann hier eine neue Generation automatischer Prüfanlagen für Laserschweißnähte, die von der Thermosensorik GmbH aus Erlangen entwickelt wurde: Buchstäblich blitzschnell, d.h. in wenigen 100 Millisekunden, durchläuft die von einem Blitz angeregte Wärmewelle das Karosseriebauteil. Gleichzeitig wird ein Infrarotvideo der gegenüberliegenden Bauteiloberfläche aufgenommen. Dieses gibt Aufschluss über die Qualität der Schweißnaht. Doch wie funktioniert dieses Verfahren?
Hoch intensiv und scharf gebündelt
Authors: Hopp Georg 
Published: October 2009

AbstractIn der Lasermaterialbearbeitung sind technische Gase unverzichtbar. Durch die Auswahl des passenden Schutzgases oder die Entwicklung eines maßgeschneiderten Gasgemischs sowie eines hochwertigen Versorgungssystems lassen sich wirtschaftliche und qualitative Faktoren des Schweiß‐ und Schneidprozesses maßgeblich beeinflussen. Damit können höhere Produktionsraten und bessere Bearbeitungsqualitäten bei gleichzeitig sinkenden Kosten erzielt werden. So führen beispielsweise in der Blechbearbeitung Helium‐Gemische mit Argon oder Wasserstoff oft zu besseren Resultaten als reines Helium. Von den Vorteilen dieser Gase und Gasgemische profitieren nicht nur Großunternehmen, sondern auch kleine und mittelständische Betriebe. Die Bedeutung der Gase für den Laserschweißprozess wird mit der Verbreitung des Laserhybrid‐Verfahrens noch weiter steigen.
SCHWEISSEN & SCHNEIDEN 2009
Authors: Middeldorf Klaus 
Published: October 2009

AbstractDie großen Messen sind derzeit gute Plätze um ein aktuelles Bild von der Wirtschaftslage zu bekommen. Auf der SCHWEISSEN & SCHNEIDEN war die Stimmung gut, ein vorsichtiger Optimismus war zu spüren. Mit dem Hauptgeschäftsführer des DVS – Deutscher Verband für Schweißen und Verwandte Verfahren e. V. sprach Andreas Thoß über die Rolle der Laserverfahren in der Fügetechnik und über die aktuelle Marktentwicklung.
High‐frequency mode conversion technique for stiff lesion detection with magnetic resonance elastography (MRE)
Authors: Mariappan Yogesh K. , Glaser Kevin J. , Manduca Armando , Romano Anthony J. , Venkatesh Sudhakar K. , Yin Meng , Ehman Richard L. 
Published: October 2009

AbstractA novel imaging technique is described in which the mode conversion of longitudinal waves is used for the qualitative detection of stiff lesions within soft tissue using magnetic resonance elastography (MRE) methods. Due to the viscoelastic nature of tissue, high‐frequency shear waves attenuate rapidly in soft tissues but much less in stiff tissues. By introducing minimally‐attenuating longitudinal waves at a significantly high frequency into tissue, shear waves produced at interfaces by mode conversion will be detectable in stiff regions, but will be significantly attenuated and thus not detectable in the surrounding soft tissue. This contrast can be used to detect the presence of stiff tissue. The proposed technique is shown to readily depict hard regions (mimicking tumors) present in tissue‐simulating phantoms and ex vivo breast tissue. In vivo feasibility is demonstrated on a patient with liver metastases in whom the tumors are readily distinguished. Preliminary evidence also suggests that quantitative stiffness measurements of stiff regions obtained with this technique are more accurate than those from conventional MRE because of the short shear wavelengths. This rapid, qualitative technique may lend itself to applications in which the localization of stiff, suspicious neoplasms is coupled with more sensitive techniques for thorough characterization. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Viable tumor tissue detection in murine metastatic breast cancer by whole‐body MRI and multispectral analysis
Authors: Barck Kai H. , Willis Brandon , Ross Jed , French Dorothy M. , Filvaroff Ellen H. , Carano Richard A. D. 
Published: October 2009

AbstractWhole‐body MRI combined with a semiautomated hierarchical multispectral image analysis technique was evaluated as a method for detecting viable tumor tissue in a murine model of metastatic breast cancer (4T1 cell line). Whole‐body apparent diffusion coefficient, T2, and proton density maps were acquired in this study. The viable tumor tissue segmentation included three‐stage k‐means clustering of the parametric maps, morphologic operations, application of a size threshold, and reader discrimination of the segmented objects. The segmentation results were validated by histologic evaluation, and the detection accuracy of the technique was evaluated at three size thresholds (15, 100, and 500 voxels). The accuracy was 88.9% for a 500‐voxel size threshold, and the area under receiver operating characteristic curve was 0.84. The regions of segmented viable tumor tissue within the primary tumors were found mostly on the periphery of the tumors in agreement with the histologic findings. The presented technique was found capable of detecting metastases and segmenting the viable tumor from necrotic regions within tumors found in this model. It offers a noninvasive, whole‐body, viable tumor tissue detection method for preclinical and potentially clinical applications such as tumor screening and evaluating therapeutic efficacy. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Superparamagnetic iron oxide nanoparticles as a dual imaging probe for targeting hepatocytes in vivo
Authors: Lee Chang‐Moon , Jeong Hwan‐Jeong , Kim Eun‐Mi , Kim Dong Wook , Lim Seok Tae , Kim Hyoung Tae , Park In‐Kyu , Jeong Yong Yeon , Kim Jin Woong , Sohn Myung‐Hee 
Published: October 2009

AbstractHepatocyte‐specific targeting agents are useful for evaluation of the hepatocytic function and the monitoring of disease progress. Superparamagnetic iron oxide nanoparticles (SPION) bearing terminal galactose groups exhibit a high affinity for the asialoglycoprotein receptor on the hepatocyte surface. In this study, we synthesized and characterized the dual probe SPION detectable by both nuclear and MR imaging modality for specifically targeting hepatocytes in vivo. SPION with 12‐nm diameter were functionalized with dopamine. Surface modification of the SPION was performed to target asialoglycoprotein receptor on hepatocytes, using lactobionic acid. Transmission electron microscope images demonstrated that SPION displayed highly uniform characteristics in terms of both particle size and shape. The X‐ray diffraction pattern of SPION revealed a nanocrystal structure of magnetite. To radiolabel the magnetite with 99mTc, diethylenetriaminepentaacetic acid was conjugated to unreacted functional groups of dopamine. 99mTc‐labeled lactobionic acid‐SPION showed high accumulation in liver, with 38.43 ± 6.45% injected dose per gram. In MR imaging, the reduction of the T2 signal in the liver by lactobionic acid‐SPION was approximately 50.8 ± 7.3%. Competition studies and transmission electron microscope images of liver tissues demonstrated that the lactobionic acid‐SPION were localized in hepatocytes. Therefore, the lactobionic acid‐SPION may be used as a hepatocyte‐targeted dual contrast agent for both nuclear and MR imaging. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Characterizing healthy and diseased white matter using quantitative magnetization transfer and multicomponent T2 relaxometry: A unified view via a four‐pool model
Authors: Levesque Ives R. , Pike G. Bruce 
Published: October 2009

AbstractNuclear magnetic resonance relaxation and magnetization transfer in cerebral white matter can be described using a four‐pool model: two for water protons (in separate myelin and intra/extracellular compartments) and two for protons associated with the lipids and proteins of biologic membranes (of myelin and nonmyelin semisolids). This model was used to gain insight into the observations from multicomponent quantitative T2 relaxometry and quantitative magnetization transfer imaging, both based on simplified white matter models and experimentally feasible in vivo. Using a set of coupled Bloch equations describing the behavior of the magnetization in a four‐pool model of white matter, simulations of the quantitative T2 relaxometry and quantitative magnetization transfer imaging techniques were performed. Pathology‐inspired modifications were made to the four‐pool model to gauge their impact on quantitative T2 relaxometry and quantitative magnetization transfer imaging observations. Our results show that changes in the rate of water movement between microanatomic compartments may impact otherwise stable quantitative T2 relaxometry observations; that the measure of the quantitative magnetization transfer imaging–based semisolid pool population is robust, despite the presence of two distinct semisolid components; and that quantitative magnetization transfer imaging compartment size estimates are not influenced by changes in the T2 of the intra/extracellular water pool. The four‐pool model, while impractical for in vivo characterization, yields important insight into the interpretation of changes observed with these quantitative MRI methods based on simplified models of white matter. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Investigation and modeling of magnetization transfer effects in two‐dimensional multislice turbo spin echo sequences with low constant or variable flip angles at 3 T
Authors: Weigel Matthias , Helms Gunther , Hennig Juergen 
Published: October 2009

AbstractMagnetization transfer effects represent a major source of contrast in multislice turbo spin echo sequences (TSE)/fast spin echo sequences. Generally, low refocusing flip angles have become common in such MRI sequences, especially to mitigate specific absorption rate problems. Since the strength of magnetization transfer effects is related to the radiofrequency power and therefore specific absorption rate applied, magnetization transfer induced signal attenuations are investigated for a variety of TSE sequences with low constant and variable flip angles. Noticeable differences between the sequences have been observed. In particular, fewer signal attenuations are observed for TSE with low flip angles such as hyperecho‐TSE and smooth transitions between pseudo steady states–TSE, leading to contrast that is less dependent on the number of slices. It is shown that the strength of the magnetization transfer‐induced signal attenuations can be understood and described by a physical framework, which is based on the mean square flip angle of a given TSE sequence. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Characterization of T2* heterogeneity in human brain white matter
Authors: Li Tie‐Qiang , Yao Bing , van Gelderen Peter , Merkle Hellmut , Dodd Stephen , Talagala Lalith , Koretsky Alan P. , Duyn Jeff 
Published: October 2009

AbstractRecent in vivo MRI studies at 7.0 T have demonstrated extensive heterogeneity of T2* relaxation in white matter of the human brain. In order to study the origin of this heterogeneity, we performed T2* measurements at 1.5, 3.0, and 7.0 T in normal volunteers. Formalin‐fixed brain tissue specimens were also studied using T2*‐weighted MRI, histologic staining, chemical analysis, and electron microscopy. We found that T2* relaxation rate (R2* = 1/T2*) in white matter in living human brain is linearly dependent on the main magnetic field strength, and the T2* heterogeneity in white matter observed at 7.0 T can also be detected, albeit more weakly, at 1.5 and 3.0 T. The T2* heterogeneity exists also in white matter of the formalin‐fixed brain tissue specimens, with prominent differences between the major fiber bundles such as the cingulum (CG) and the superior corona radiata. The white matter specimen with substantial difference in T2* has no significant difference in the total iron content, as determined by chemical analysis. On the other hand, evidence from histologic staining and electron microscopy demonstrates these tissue specimens have apparent difference in myelin content and microstructure. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Delayed gadolinium‐enhanced magnetic resonance imaging (dGEMRIC) of hip joint cartilage in femoroacetabular impingement (FAI): Are pre‐ and postcontrast imaging both necessary?
Authors: Bittersohl Bernd , Hosalkar Harish S. , Kim Young‐Jo , Werlen Stefan , Siebenrock Klaus A. , Mamisch Tallal C. 
Published: October 2009

AbstractThe purpose of this study was to assess if delayed gadolinium MRI of cartilage using postcontrast T1 (T1Gd) is sufficient for evaluating cartilage damage in femoroacetabular impingement without using noncontrast values (T10). T1Gd and ΔR1 (1/T1Gd − 1/T10) that include noncontrast T1 measurements were studied in two grades of osteoarthritis and in a control group of asymptomatic young‐adult volunteers. Differences between T1Gd and ΔR1 values for femoroacetabular impingement patients and volunteers were compared. There was a very high correlation between T1Gd and ΔR1 in all study groups. In the study cohort with Tonnis grade 0, correlation (r) was −0.95 and −0.89 with Tonnis grade 1 and −0.88 in asymptomatic volunteers, being statistically significant (P < 0.001) for all groups. For both T1Gd and ΔR1, a statistically significant difference was noted between patients and control group. Significant difference was also noted for both T1Gd and ΔR1 between the patients with Tonnis grade 0 osteoarthritis and those with grade 1 changes. Our results prove a linear correlation between T1Gd and ΔR1, suggesting that T1Gd assessment is sufficient for the clinical utility of delayed gadolinium MRI of cartilage in this setting and additional time‐consuming T10 evaluation may not be needed. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Reconstruction from free‐breathing cardiac MRI data using reproducing kernel Hilbert spaces
Authors: Cîndea Nicolae , Odille Freddy , Bosser Gilles , Felblinger Jacques , Vuissoz Pierre‐André 
Published: October 2009

AbstractThis paper describes a rigorous framework for reconstructing MR images of the heart, acquired continuously over the cardiac and respiratory cycle. The framework generalizes existing techniques, commonly referred to as retrospective gating, and is based on the properties of reproducing kernel Hilbert spaces. The reconstruction problem is formulated as a moment problem in a multidimensional reproducing kernel Hilbert spaces (a two‐dimensional space for cardiac and respiratory resolved imaging). Several reproducing kernel Hilbert spaces were tested and compared, including those corresponding to commonly used interpolation techniques (sinc‐based and splines kernels) and a more specific kernel allowed by the framework (based on a first‐order Sobolev RKHS). The Sobolev reproducing kernel Hilbert spaces was shown to allow improved reconstructions in both simulated and real data from healthy volunteers, acquired in free breathing. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.
2D modelling of a dry joint masonry wall retaining a pulverulent backfill
Authors: Colas A. S. , Morel J. C. , Garnier D. 
Published: October 2009

AbstractThis work focuses on an analysis of dry joint retaining structures based on yield design theory: the stability of the masonry is assessed using rigid block and shear failure mechanisms in the wall and its backfill. An application of this simulation on 2D scale‐down brick and wood models is then addressed, showing close agreement between theoretical predictions and experimental results. Further development on this work, including application of this theory on dry‐stone retaining walls, is discussed as a conclusion. Copyright © 2009 John Wiley & Sons, Ltd.
A coupled model for prediction of settlement and gas flow in MSW landfills
Authors: Yu L. , Batlle F. , Lloret A. 
Published: October 2009

AbstractPrediction of long‐term settlement and control of gas pollution to the environment are two principle concerns during the management of municipal solid waste (MSW) landfills. The behavior of settlement and gas flow in MSW landfills is complicated due to the combined effect of mechanical deformation of the solid skeleton and continuous biodegradation of the waste. A one‐dimensional settlement and gas flow model is presented in this paper, which is capable of predicting time evolution of settlement as well as temporal and spatial distribution of gas pressure within multi‐layered landfills under a variety of operating scenarios. The analytical solution to the novel model is evaluated with numerical simulation and field measurements. The resulting efficiency and accuracy highlight the capability of the proposed model to reproduce the settlement behavior and gas flow in MSW landfills. The influences of operating conditions and waste properties on settlement and gas pressure are examined for typical MSW landfills. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of pile installation on adjacent structures
Authors: Henke S. 
Published: October 2009

AbstractPile installation leads to significant changes in the main state variables of the surrounding soil. In addition, the installation process may have an influence on adjacent or intersecting structures such as pile grillages. In this paper, three‐dimensional numerical analyses are presented to investigate the effects of pile driving with open or closed cross‐sections on the surrounding soil and on adjacent structures. Two different installation methods are used: quasi‐static pile jacking and vibratory pile driving. The numerical models are evaluated and verified using data from field tests performed in situ during the construction of the quay wall at the container terminal CT4 in Bremerhaven.Two case studies are presented to characterize the main influence factors for additional loading on adjacent structures due to pile installation.Finally, a parametric study is conducted showing the influence of the installation method, pile cross‐section and distance of a pile from an existing structure on the additional loading for this structure. Copyright © 2009 John Wiley & Sons, Ltd.
Synchronously synthesizing and immobilizing porphyrins on crosslinked polystyrene microspheres and preliminary study on catalytic activity of supported metalloporphyrins
Authors: Gao Baojiao , Zhang Guohai , Li Yanbin , Du Ruikui 
Published: October 2009

AbstractA novel method for immobilizing porphyrins as well as metalloporphyrins (MPs) on polymeric supports was found, and it is the way to synchronously synthesize and immobilize porphyrins on polymeric microspheres. By using 4‐hydroxybenzaldehyde (HBA)‐bound crosslinked polystyrene (CPS) microspheres, pyrrole, and benzaldehyde in a solution as co‐reactants and through the Adler's reaction between solid–liquid phases, it was successfully realized to simultaneously synthesize and immobilize phenyl porphyrin (PP) on CPS microspheres, resulting in PP‐supported microspheres PP–CPS. With the same method, substituted PPs, 4‐chlorophenyl porphyrin (CPP) and 4‐nitrophenyl porphyrin (NPP), were also successfully immobilized on CPS microspheres by using substituted benzaldehydes, 4‐chlorobenzaldehyde and 4‐nitrobenzaldehyde, as one reactant in the solution, respectively, and other two porphyrin‐supported microspheres, CPP–CPS and NPP–CPS, were obtained. The effects of various factors on the process of synchronously synthesizing and immobilizing porphyrins on CPS microspheres were mainly studied. Further, the coordination reaction of cobalt salt with PP–CPS as well as CPP–CPS and NPP–CPS was conducted, forming three solid catalysts, CoPP–CPS, CoCPP–CPS, and CoNPP–CPS. The catalytic properties of these catalysts in the catalytic oxidation of ethylbenzene to acetophenone by dioxygen were preliminarily examined. The experimental results indicate that the Adler's reaction between solid–liquid phases, namely the reaction between HBA‐bound CPS microspheres and pyrrole as well as free benzaldehyde or analogs in the solution can favorably be carried out. For this process, the fitting protonic acid catalyst is p‐nitrobenzoic acid and appropriate solvent is dimethyl sulfoxide (DMSO). By comparison, the process of preparing CPP–CPS microspheres is easier to be carried out. The obtained three solid catalysts can effectively catalyze the oxidation of ethylbenzene to acetophenone by dioxygen. In comparison, the catalytic activity of CoNPP–CPS is the highest. Copyright © 2009 John Wiley & Sons, Ltd.