bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Microfabrication of Topographical and Chemical Cues for the Guided Growth of Neural Cell Networks on Polyamidoamine Hydrogels
Authors: Dos Reis Gabriel , Fenili Fabio , Gianfelice Antonella , Bongiorno Gero , Marchesi Davide , Scopelliti Pasquale Emanuele , Borgonovo Antonio , Podestà Alessandro , Indrieri Marco , Ranucci Elisabetta , Ferruti Paolo , Lenardi Cristina , Milani Paolo 
Published: May 2010

AbstractCell patterning is an important tool for organizing cells in surfaces and to reproduce in a simple way the tissue hierarchy and complexity of pluri‐cellular life. The control of cell growth, proliferation and differentiation on solid surfaces is consequently important for prosthetics, biosensors, cell‐based arrays, stem cell therapy and cell‐based drug discovery concepts. We present a new electron beam lithography method for the direct and simultaneous fabrication of sub‐micron topographical and chemical patterns, on a biocompatible and biodegradable PAA hydrogel. The localized e‐beam modification of a hydrogel surface makes the pattern able to adsorb proteins in contrast with the anti‐fouling surface. By also exploiting the selective attachment, growth and differentiation of PC12 cells, we fabricated a neural network of single cells connected by neuritis extending along microchannels. E‐beam microlithography on PAA hydrogels opens up the opportunity of producing multifunctional microdevices incorporating complex topographies, allowing precise control of the growth and organization of individual cells.magnified image
Donor–π–Acceptor Polymer with Alternating Triarylborane and Triphenylamine Moieties
Authors: Li Haiyan , Jäkle Frieder 
Published: May 2010

AbstractA luminescent main chain donor–π–acceptor‐type polymer (4) was prepared via organometallic polycondensation reaction followed by post modification. With both electron‐rich amine and electron‐deficient borane moieties embedded in the main chain, 4 exhibits an interesting ambipolar character: it can be reduced and oxidized electrochemically at moderate potentials and shows a strong solvatochromic effect in the emission spectra. Complexation studies show that 4 selectively binds to fluoride and cyanide; quantitative titration with cyanide reveals a two‐step binding process.magnified image
Radical Desorption Kinetics in Emulsion Polymerization, 2 – Brownian Dynamics Simulation of Radical Desorption in Non‐Homogeneous Particles
Authors: Hernandez Hugo F. , Tauer Klaus 
Published: May 2010

AbstractOne of the most important events in free‐radical emulsion polymerization is desorption of radicals from the polymer particles to the aqueous phase. Desorption takes place by diffusion of radicals inside the particle toward the surface and transfer to the aqueous phase. The rate of desorption can be determined theoretically for homogeneous spherical particles. For more complex cases, analytical solutions become difficult or impossible to obtain and a numerical approach is better suited for estimating desorption rate coefficients. In this paper, Brownian dynamics simulation is used for the estimation of desorption rate coefficients in emulsion polymerization systems of increased complexity, in particular for non‐homogeneous polymer particles.magnified image
The equine oocyte: Factors affecting meiotic and developmental competence
Authors: Hinrichs Katrin 
Published: May 2010

AbstractThere is currently much interest in assisted reproduction techniques in the horse, however, many aspects of oocyte maturation, fertilization, and embryo development in the horse differ from those in other species. Because of the close attachment of the equine oocyte to the follicle wall, scraping of the follicle is the most effective method for oocyte recovery. A notable feature of equine oocytes is that those with expanded cumuli (Ex oocytes), which originate from atretic follicles, have higher meiotic competence (ability to mature to metaphase II in vitro) than do oocytes with compact cumuli (Cp oocytes). Cp oocytes originate in viable follicles but are largely juvenile. Recovery and culture of equine oocytes immediately after slaughter yields a higher maturation rate than that obtained from oocytes after ovary storage; this is related to damage to chromatin in Cp oocytes during storage. In contrast, developmental competence (rate of blastocyst development in vitro) is higher in oocytes recovered from the ovary after a delay. The optimum duration of maturation varies based on cumulus morphology and time of recovery from the ovary, but there is no difference in developmental competence between Ex and Cp oocytes. Because standard in vitro fertilization is not repeatable in the horse, oocyte transfer (surgical transfer of oocytes to the oviducts of inseminated mares) has been developed to allow fertilization of isolated oocytes. Fertilization in vitro may be achieved using intracytoplasmic sperm injection; culture of injected oocytes in a medium with high glucose can yield over 30% blastocyst development. Mol. Reprod. Dev. 77: 651–661, 2010. © 2010 Wiley‐Liss, Inc.
Dual‐band water and lipid suppression for MR spectroscopic imaging at 3 Tesla
Authors: Zhu He , Ouwerkerk Ronald , Barker Peter B. 
Published: May 2010

AbstractA dual‐band water and lipid suppression sequence was developed for multislice sensitivity‐encoded proton MR spectroscopic imaging of the human brain. The presaturation scheme consisted of five dual‐band frequency‐modulated radiofrequency pulses based on hypergeometric functions integrated with eight outer volume suppression (OVS) pulses. The flip angles of the dual‐band pulses were optimized through computer simulations to maximize suppression factors over a range of transmitter amplitude of radiofrequency field and water and lipid T1 values. The resulting hypergeometric dual band with OVS (HGDB + OVS) sequence was implemented at 3 T in a multislice sensitivity‐encoded proton MR spectroscopic imaging experiment and compared to a conventional water suppression scheme (variable pulse power and optimized relaxation delays (VAPOR)) with OVS. The HGDB sequence was significantly shorter than the VAPOR sequence (230 versus 728 msec). Both HGDB + OVS and VAPOR + OVS produced good water suppression, while lipid suppression with the HGDB + OVS sequence was far superior. In sensitivity‐encoded proton MR spectroscopic imaging data, artifacts from extracranial lipid signals were significantly lower with HGDB + OVS. The shorter duration of HGDB compared to VAPOR also allows reduced pulse repetition time values in the multislice acquisition. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
An efficient gridding reconstruction method for multishot non‐Cartesian imaging with correction of off‐resonance artifacts
Authors: Meng Yuguang , Lei Hao 
Published: May 2010

AbstractAn efficient iterative gridding reconstruction method with correction of off‐resonance artifacts was developed, which is especially tailored for multiple‐shot non‐Cartesian imaging. The novelty of the method lies in that the transformation matrix for gridding (T) was constructed as the convolution of two sparse matrices, among which the former is determined by the sampling interval and the spatial distribution of the off‐resonance frequencies and the latter by the sampling trajectory and the target grid in the Cartesian space. The resultingTmatrix is also sparse and can be solved efficiently with the iterative conjugate gradient algorithm. It was shown that, with the proposed method, the reconstruction speed in multiple‐shot non‐Cartesian imaging can be improved significantly while retaining high reconstruction fidelity. More important, the method proposed allows tradeoff between the accuracy and the computation time of reconstruction, making customization of the use of such a method in different applications possible. The performance of the proposed method was demonstrated by numerical simulation and multiple‐shot spiral imaging on rat brain at 4.7 T. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Gadolinium‐labeled quantum dots for molecular magnetic resonance imaging: R1 versus R2 mapping
Authors: Oostendorp Marlies , Douma Kim , Hackeng Tilman M. , Post Mark J. , van Zandvoort Marc A. M. J. , Backes Walter H. 
Published: May 2010

AbstractQuantum dots labeled with paramagnetic gadolinium chelates can be applied as contrast agent for preclinical molecular MRI combined with fluorescence microscopy. Besides increasing the longitudinal relaxation rate, gadolinium‐labeled quantum dots may increase the transverse relaxation rate, which might be related to their magnetic properties. Furthermore, molecular MRI experiments are primarily conducted at high magnetic fields, where longitudinal relaxation rate becomes less effective, and the use of transverse relaxation rate as a source of contrast may become attractive. Consequently, the optimal method of contrast enhancement using gadolinium‐labeled quantum dots is a priori unknown. The objective of this study was to compare longitudinal relaxation rate– and transverse relaxation rate–based contrast enhancement, proton visibility, and changes thereof induced by gadolinium‐labeled quantum dots targeted to the angiogenic vasculature of murine tumors, using in vivo longitudinal and transverse relaxation rate mapping. At a field strength of 7 T, longitudinal relaxation rate–based measures were superior to transverse relaxation rate–based measures in detecting both the level and spatial extent of contrast agent–induced relaxation rate changes. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Comparative SNR for high‐throughput mouse embryo MR microscopy
Authors: Zhang Xiaoli , Schneider Jurgen E. , Portnoy Sharon , Bhattacharya Shoumo , Henkelman R. Mark 
Published: May 2010

AbstractMR microscopy is being explored as a useful imaging tool to phenotype mouse embryos due to its volume coverage with three‐dimensional isotropic resolution. However, the main limitation for mouse embryo MR microscopy is the signal‐to‐noise ratio. Large numbers of embryos are needed for phenotypic screening, making high throughput essential. Two high‐throughput imaging approaches, multi‐embryo shared‐coil (shared) and multi‐embryo individual‐coil (individual), have been developed for phenotyping mouse embryos. This study quantitatively compares the signal‐to‐noise ratio at equivalent times between these two established methods by compensating for differences that result from field strength. While the individual method provides 3.3 times as much signal‐to‐noise ratio as the shared method at equivalent conditions, it is more difficult and expensive to implement. Furthermore, the number of embryos that can be imaged concurrently is limited by the number of receiver channels. The objective of this study is to provide measured comparative data to guide choices for high‐throughput mouse embryo MR microscopy and other similar applications. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Spatially resolved assessment of serotonin‐induced bronchoconstrictive responses in the rat lung using 3He ventilation MRI under spontaneous breathing conditions
Authors: Mosbah Karim , Stupar Vasile , Berthezène Yves , Beckmann Nicolau , Crémillieux Yannick 
Published: May 2010

AbstractThe effect on lung ventilation of bronchoconstriction induced by serotonin (intravenous injection of 50 μg/kg of serotonin) was imaged using a hyperpolarized 3He MR ventilation protocol in spontaneously breathing rats. Lung function maps assessing airflow obstruction, a key feature in clinical pneumology, were derived from dynamic image series acquired after inhalation of 3He gas. Dynamic ventilation 3He MR images spanning a respiratory cycle were obtained using a retrospective cine image reconstruction procedure. Two parameters, defined as signal amplitude and maximum signal decay rate, were derived from the time course of the MR signal for each pixel. These parameters were averaged over regions of interest placed in the lower part of the right and left lungs and submitted to statistical analysis. A homogeneous and significant decrease of signal amplitude and maximum signal decay rate after serotonin injection was observed for each rat on the parametric color maps. The data indicate that dynamic ventilation HP 3He MRI can be used to assess, in a spatially resolved manner, the ventilation function of spontaneously breathing rats and the effects of agents eliciting short‐lasting bronchoconstriction. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Improvement of hyperemic myocardial oxygen extraction fraction estimation by a diffusion‐prepared sequence
Authors: McCommis Kyle S. , Koktzoglou Ioannis , Zhang Haosen , Goldstein Thomas A. , Northrup Benjamin E. , Li Debiao , Gropler Robert J. , Zheng Jie 
Published: May 2010

AbstractMyocardial oxygen extraction fraction (OEF) during hyperemia can be estimated using a double‐inversion‐recovery‐prepared T2‐weighted black‐blood sequence. Severe irregular electrocardiogram (ECG) triggering due to elevated heart rate and/or arrhythmias may render it difficult to adequately suppress the flowing left ventricle blood signal and thus potentially cause errors in the estimates of myocardial OEF. Thus, the goal of this study was to evaluate another black‐blood technique, a diffusion‐weighted‐prepared turbo spin echo sequence for its ability to determine regional myocardial OEF during hyperemia. Control dogs and dogs with acute coronary artery stenosis were imaged with both the double‐inversion‐recovery‐ and diffusion‐weighted‐prepared turbo spin echo sequences at rest and during either dipyridamole or dobutamine hyperemia. Validation of MRI OEF estimates was performed using blood sampling from the artery and coronary sinus in control dogs. The two methods showed comparable correlations with blood sampling results (R2 = 0.9). Similar OEF estimations for all dogs were observed, except for the group of dogs with severe coronary stenosis during dobutamine stress. In these dogs, the diffusion‐weighted method provided more physiologically reasonable OEF (hyperemic OEF = 0.75 ± 0.08 versus resting OEF of 0.6) than the double‐inversion‐recovery method (hyperemic OEF = 0.56 ± 0.10). Diffusion‐weighted preparation may be a valuable alternative for more accurate oxygenation measurements during irregular ECG‐triggering. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Steadiness in plantar flexor muscles and its relation to postural sway in young and elderly adults
Authors: Kouzaki Motoki , Shinohara Minoru 
Published: May 2010

AbstractTo investigate the functional significance of force fluctuations during voluntary contraction with a select muscle group, we examined the association between force fluctuations during voluntary contraction with plantar flexor muscles and postural sway during quiet standing in 20 young and 20 elderly adults. Young and elderly subjects maintained a quiet standing position on a force platform. They also performed a force‐matching task with unilateral isometric plantar flexion. A positive correlation was found in young and elderly adults between the coefficient of variation (CV) of center of pressure during quiet standing and the CV of force during plantar flexion only at contraction intensities of ≤5% maximum voluntary contraction that corresponded to muscle activity during quiet standing. The electromyogram power in the medial gastrocnemius was greater in the elderly than in young adults by ∽10 HZ during quiet standing and at low contraction intensities during plantar flexion. Fluctuations in motor output during low‐intensity plantar flexion were associated with postural sway during quiet standing in both young and elderly adults. Muscle Nerve, 2010
Transgenic overexpression of laminin α1 chain in laminin α2 chain–deficient mice rescues the disease throughout the lifespan
Authors: Gawlik Kinga I. , Durbeej Madeleine 
Published: May 2010

AbstractSeveral approaches to treat laminin α2 chain–deficient congenital muscular dystrophy (MDC1A) in mouse models have been undertaken. Most have shown promising results in young animals. However, older animals have only been characterized to some extent. Herein we analyze the lifespan of laminin α2 chain–deficient mice with transgenic overexpression of laminin α1 chain. Further outcome measures included internalized myonuclei, heart fibrosis, grip strength, and serum creatine kinase activity. We show that laminin α2‐chain–deficient animals that overexpress laminin α1 chain survive to up to 1.5–2 years of age. Furthermore, they displayed improved skeletal and heart muscle morphology, near‐normal muscle strength, and normalized creatine kinase levels. Such an improvement of the dystrophic phenotype that persists to old age has not been previously demonstrated in mice. Our findings hold promise with regard to the efficient treatment of MDC1A patients in the future. Muscle Nerve, 2010
Membranen aus dem Computer?
Authors: Hofmann Dieter 
Published: May 2010

AbstractWie gewinnt man energiesparend Sauerstoff aus Luft, reduziert die Belastung der Atemluft mit Benzol in Tankstellen und trennt Ethanol aus wässrig‐ethanolischen Gemischen ab? Diese und viele weitere Vorgänge der Stofftrennung gelingen mit Polymermembranen. Das Interesse an der Entwicklung von neuen Polymeren mit verbesserten Eigenschaften ist daher groß; ein wichtiges Werkzeug dafür ist Molecular Modelling.
Dendrimere: Das Forschungsgebiet wächst und verzweigt sich
Authors: Lüning Ulrich 
Published: May 2010

AbstractKaskadenmoleküle durch repetitive Reaktionen aufzubauen und dann gezielt zu modifizieren ‐dieser Ansatz birgt viel Potential. Dendrimere sind längst kein Thema mehr nur für die Grundlagenforschung, auch Industriefirmen haben Projekte initiiert oder bieten bereits Produkte auf Dendrimerbasis an.
bac+5: Mit Baguette, Käse und Rotwein
Authors: Krüger Anke 
Published: May 2010

AbstractFrankreich als Studienort ist zwar nicht exotisch, aber gerade für Chemiker immer noch ziemlich ungewöhnlich. Dabei bietet unser größtes Nachbarland vielfältige Möglichkeiten, einen Teil des Studiums oder die gesamte Ausbildung dort zu absolvieren.
Das Phantom wurde Programm
Authors: Feil Sylvia 
Published: May 2010

AbstractDas Phantom der chemischen Fakultät in Madison ist fast 40 Jahre alt. Aber es spukt nicht des Nachts durch die Räume, wohnt nicht in Katakomben. In der Hauptstadt von Wisconsin im mittleren Westen der USA geht alles mit rechten Dingen zu: Das Phantom ist für gewöhnlich ein Privatdozent. Die Universität von Wisconsin lud bereits 55 Gastprofessoren ein, von denen weit über die Hälfte aus Deutschland kamen.
„Gene prospecting”︁ ‐ die Jagd nach Geninformation
Authors: Maelicke Alfred 
Published: May 2010

AbstractMikroarrayverfahren haben die Analyse von genetischem Material revolutioniert. Schon kann man im „Netz”︁ mit dem MGuide eine Selbstbauanleitung für einen Microarrayroboter finden. Das „gene prospecting”︁, die Suche nach Bioinformation im Land der Gene und im Stil der früheren Gold‐ und Ölsucher ist auf seinem Höhepunkt angelangt.
Elektronische Drehscheiben für die Laborversorgung
Authors: Cuggolz Ernst 
Published: May 2010

AbstractWährend im US‐Markt bereits einige E–Commerce‐Anbieter das Labor versorgen, fehlt in Europa noch eine Schaltstelle, die ausschließlich für den Einkauf und die Informationsvermittlung arbeitet. eLabsEurope ‐ ein neuer Anbieter mit Ambitionen ‐ startet seinen Dienst mit Venture‐Kapital und zeigt, wie ein solitäres E‐Commerce‐System arbeitet
Neue Methoden der quantitativen Fluoreszenzanalyse in der Mikroskopie
Authors: Maass Martin , Pfuhl Andreas 
Published: May 2010

AbstractFür die Lokalisierung von Proteinen in Zellen eignen sich licht‐ und elektronenmikroskopische Verfahren. Dazu werden Proteine über eine Antikörperkopplung oder über die Cosysnthese eines fluoreszierenden Proteins markiert.
50 Jahre GDCh‐Mitgliedschaft ‐Wir gratulieren!
Authors: Erker Gerhard , Dieck Heindirk Tom 
Published: May 2010

AbstractIm Jahre 2000 feiern zahlreiche Kolleginnen und Kollegen das goldene Jubiläum ihrer GDCh–Mitgliedschaft und damit 50 Jahre fruchtbarer und erfolgreicher Zusammenarbeit. Unseren treuen und langjährigen Mitgliedern danken wir, dass sie den Weg ins neue Millennium gemeinsam mit uns beschritten haben. Bleiben Sie noch recht lange aktiv an unserer Seite! Unsere Grüße und Glückwünsche gelten
Die Brennstoffzelle: eine Zukunftstechnologie
Authors: Friedrich Kaspar Andreas 
Published: May 2010

AbstractBrennstoffzellen gelten als Schlüsselelemente einer künftigen Energieversorgung. Auf ihnen ruhen die Hoffnungen der Automobilindustrie auf schadstofffreie Motoren; sie sind aber genauso gefragt für die dezentrale, umweltfreundliche Energieversorgung von Gebäuden oder Industrieanlagen.
Chemie zwischen Effekthascherei und Sachlichkeit
Authors: Vaupel Elisabeth 
Published: May 2010

AbstractAusstellungen zur Chemie haben immer damit zu kämpfen, dass eine attraktive, publikumswirksame Präsentation von Rohstoffen, Produkten und Verfahren sehr schwer ist. Die Weltausstellungen des 19. Jahrhunderts dokumentieren dieses Problem und zeigen, dass die Interessen der Laien über Jahrzehnte ignoriert wurden.
Chemie auf der Expo: Ein Mix aus Gefühl und Wissenschaft
Authors: Guggolz Ernst 
Published: May 2010

AbstractAuch für die Expo 2000 gilt: „Alles ist Chemie”︁. Deutlich wird das in Hannover im und rund ums „Chemidrom”︁ in Halle 7, im „Science Tunnel”︁ in Halle 4 und beim dreitägigen „Global Dialogue: Science & Technology ‐ Think the Future”︁. Doch die Aussteller von Auto bis Zug übergehen in Hannover und bei den weltweiten Projekten häufig ihre chemische Basis.
Chemische Sensoren in der Wassertechnologie
Authors: Nießner Reinhard 
Published: May 2010

AbstractDie vermeintlich simple Matrix Wasser ist alles andere als trivial. Die enorme Vielfalt an Analyten in ihren verschiedensten Erscheinungsformen und enorm unterschiedlichen Matrixzusammensetzungen haben ein breites Vordringen von Sensoren bislang verhindert. Hoffnung auf ein höheres Anwendungs‐ und Verbreitungspotential machen die enormen Fortschritte der Chiptechnologien und der optischen Sensorik.
Wo liegt die Zukunft der chemischen Industrie ?
Authors: Meyer‐Galow Erhard 
Published: May 2010

AbstractDie chemische Industrie wird derzeit vom Kapitalmarkt nicht gerade bevorzugt. Die Firmen der New Economy, denen die Chemie oft zum Leben verholfen hat, laufen ihr den Rang ab. In den nächsten Dekaden gibt es aber genug Raum für die Chemie, um ein Feuerwerk an Innovationen bei Produkten und Prozessen zu entzünden.
Promotion of Chemical Research Transcends National Boundaries
Authors: Schmidt Karlhenz , Chemie Referatsleiter 
Published: May 2010

AbstractIn the autumn of 1999, nine European national research promotion organisations took the unprecedented step of soliciting joint, transnational applications for chemical research grants. The nine also agreed upon joint evaluation of the applications, while maintaining national financing of the research. The role of this initiative by the Chairmen of European Research Councils' Chemistry Committees (CERC 3) is specifically to supplement – and not to challenge – existing programmes of the European Union (EU), the European Science Foundation (ESF) and the European Committee on Science and Technology (COST). Thirteen transnational application packages have been submitted so far by 50 working groups from eight European countries. The research is to be conducted in the highly topical fields „Topological Stereochemistry, Topological Chirality”︁ and „Molecules at Complex Surfaces: Bond Forming, Bond Breaking and Dynamics”︁.
Neurodegenerative Erkrankungen: Auslösung durch zufälligen Zelltod?
Authors: Maelicke Alfred 
Published: May 2010

AbstractAuch genetisch bedingte neurodegenerative Erkrankungen brechen gewöhnlich erst in späteren Lebensphasen aus. Erfordert der Krankheitsausbruch ‐ wie bisher angenommen ‐vorausgehende kumulative Zellschädigungen oder ist er eher ein singuläres Zufallsereignis?
www.chemie‐im‐fokus.de
Authors: Hoer Renate 
Published: May 2010

AbstractDie Gesellschaft Deutscher Chemiker (GDCh) hat gemeinsam mit dem Fonds der Chemischen Industrie (FCI) eine neue Internetadresse eingerichtet, die sich speziell an Schüler richtet; www.chemie‐im‐fokus‐de.