bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐frequency oscillations as a new biomarker in epilepsy
Authors: Zijlmans Maeike , Jiruska Premysl , Zelmann Rina , Leijten Frans S.S. , Jefferys John G.R. , Gotman Jean 
Published: August 2011

AbstractThe discovery that electroencephalography (EEG) contains useful information at frequencies above the traditional 80Hz limit has had a profound impact on our understanding of brain function. In epilepsy, high‐frequency oscillations (HFOs, >80Hz) have proven particularly important and useful. This literature review describes the morphology, clinical meaning, and pathophysiology of epileptic HFOs. To record HFOs, the intracranial EEG needs to be sampled at least at 2,000Hz. The oscillatory events can be visualized by applying a high‐pass filter and increasing the time and amplitude scales, or EEG time‐frequency maps can show the amount of high‐frequency activity. HFOs appear excellent markers for the epileptogenic zone. In patients with focal epilepsy who can benefit from surgery, invasive EEG is often required to identify the epileptic cortex, but current information is sometimes inadequate. Removal of brain tissue generating HFOs has been related to better postsurgical outcome than removing the seizure onset zone, indicating that HFOs may mark cortex that needs to be removed to achieve seizure control. The pathophysiology of epileptic HFOs is challenging, probably involving populations of neurons firing asynchronously. They differ from physiological HFOs in not being paced by rhythmic inhibitory activity and in their possible origin from population spikes. Their link to the epileptogenic zone argues that their study will teach us much about the pathophysiology of epileptogenesis and ictogenesis. HFOs show promise for improving surgical outcome and accelerating intracranial EEG investigations. Their potential needs to be assessed by future research. Ann Neurol 2012;71:169–178
Systemic inflammation induces axon injury during brain inflammation
Authors: Moreno Beatriz , Jukes John‐Paul , Vergara‐Irigaray Nuria , Errea Oihana , Villoslada Pablo , Perry V. Hugh , Newman Tracey A. 
Published: August 2011

AbstractObjective:Axon injury is a key contributor to the progression of disability in multiple sclerosis (MS). Systemic infections, which frequently precede relapses in MS, have been linked to clinical progression in Alzheimer's disease. There is evidence of a role for the innate immune system in MS lesions, as axonal injury is associated with macrophage activation. We hypothesize that systemic inflammation leads to enhanced axonal damage in MS as a consequence of innate immune system activation.Methods:Monophasic experimental allergic encephalomyelitis (EAE) was induced in a cohort of Lewis rats. The animals received a systemic challenge with either an inflammagen (lipopolysaccharide [LPS]) or saline as a control, at 1, 3, or 6 weeks into the remission phase of the disease. The clinical outcome, cellular recruitment to lesions, degree of tissue damage, and cytokine profiles were measured.Results:We found that systemic inflammation activates the central nervous system (CNS) innate immune response and results in a switch in the macrophage/microglia phenotype. This switch was accompanied by inducible nitric oxide synthase (iNOS) and interleukin‐1β (IL‐1β) expression and increased axon injury. This increased injury occurred independently of the re‐emergence of overt clinical signs.Interpretation:Our evidence indicates that microglia/macrophages, associated with lesions, respond to circulating cytokines, produced in response to an inflammatory event outside the CNS, by producing immune mediators that lead to tissue damage. This has implications for people with MS, in which prevention and stringent management of systemic infectious diseases may slow disease progression. ANN NEUROL 2011;70:932–942
Tribological behavior of polyetheretherketone composites containing short carbon fibers and potassium titanate whiskers in dry sliding against steel
Authors: Ma N. , Lin G. M. , Xie G. Y. , Sui G. X. , Yang R. 
Published: August 2011

AbstractPolyetheretherketone (PEEK) composites reinforced by short carbon fibers (SCF) and potassium titanate whiskers (PTW) were prepared using twin‐screw extrusion compounding and injection molding. The tribological properties of hybrid composites were investigated in dry sliding condition against steel. The effects of filler contents on the wear behavior were studied. It was found that the hybrid composite showed an excellent tribological property in dry sliding condition. Applied load had great effect on the tribological behavior of the composites. In most cases, the friction coefficient of the composite decreased with the load rising. The composites with higher CF contents showed outstanding tribological performances at low load but could worsen the wear behavior at high load. Because of the positive effect of PTW, high PTW loading composites presented low wear rate at low load. At high loads, the composites with lower PTW contents had better wear resistance. The scanning electron microscopy (SEM) observation revealed that abrasion wear was attributed to the lower wear resistance of the high PTW content composite at high load. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation of chitosan‐coated magnetite nanoparticles and application for immobilization of laccase
Authors: Kalkan Nuzhet Ayca , Aksoy Serpil , Aksoy Eda Ayse , Hasirci Nesrin 
Published: August 2011

AbstractIn this study, immobilization of laccase (L) enzyme on magnetite (Fe3O4) nanoparticles was achieved, so that the immobilized enzyme could be used repeatedly. For this purpose, Fe3O4 nanoparticles were coated and functionalized with chitosan (CS) and laccase from Trametes versicolor was immobilized onto chitosan‐coated magnetic nanoparticles (Fe3O4‐CS) by adsorption or covalent binding after activating the hydroxyl groups of chitosan with carbodiimide (EDAC) or cyanuric chloride (CC). For chitosan‐coated magnetic nanoparticles, the thickness of CS layer was estimated as 1.0–4.8 nm by TEM, isoelectric point was detected as 6.86 by zeta (ζ)‐potential measurements, and the saturation magnetization was determined as 25.2 emu g−1 by VSM, indicating that these nanoparticles were almost superparamagnetic. For free laccase and immobilized laccase systems, the optimum pH, temperature, and kinetic parameters were investigated; and the change of the activity against repeated use of the immobilized systems were examined. The results indicated that all immobilized systems retained more than 71% of their initial activity at the end of 30 batch uses. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Impaired dendritic cell proinflammatory cytokine production in psoriatic arthritis
Authors: Wenink Mark H. , Santegoets Kim C. M. , Butcher John , van Bon Lenny , Lamers‐Karnebeek Femke G. M. , van den Berg Wim B. , van Riel Piet L. C. M. , McInnes Iain B. , Radstake Timothy R. D. J. 
Published: August 2011

AbstractObjectiveThe pathogenesis of psoriatic arthritis (PsA) remains poorly understood. The underlying chronic inflammatory immune response is thought to be triggered by unknown environmental factors potentially arising from a defective immune function. We undertook this study to determine whether an impaired acute inflammatory response by dendritic cells (DCs) might compromise the clearance of bacteria and predispose to chronic inflammation.MethodsWe determined cytokine production by DCs from healthy controls and from patients with rheumatoid arthritis, PsA, and psoriasis in response to Mycobacterium tuberculosis, Mycobacterium avium paratuberculosis, and a range of other bacteria and Toll‐like receptor (TLR) ligands. Phenotypic differences involved in cellular responses against (myco)bacteria were determined by quantitative polymerase chain reaction and flow cytometry.ResultsThe secretion of proinflammatory cytokines by PsA DCs was impaired upon in vitro challenge with mycobacteria and TLR‐2 ligands. This impairment was associated with elevated serum levels of C‐reactive protein. The expression of TLR‐2 and other receptors known to mediate mycobacterial recognition was unaltered. In contrast, the intracellular TLR inhibitors suppressor of cytokine signaling 3 and A20 were more highly expressed in DCs from PsA patients. PsA DCs further demonstrated up‐regulated levels of ATG16L1, NADPH oxidase 2, and LL37, which are molecules implicated in the immune response against intracellular bacteria.ConclusionOur findings indicate that DCs from PsA patients have a disordered immune response toward some species of (myco)bacteria. This might predispose to impaired immune responses to, and in turn impaired clearance of, these bacteria, setting the stage for the chronic inflammation of joints, entheses, skin, and the gut.
Biodiversität und Klima: Wandel in vollem Gange!
Authors: Streit Bruno , Böhning‐Gaese Katrin , Mosbrugger Volker 
Published: August 2011

AbstractDer globale Wandel ist in vollem Gange und betrifft nicht nur das Klima, sondern auch die Biodiversität. Gleichzeitig führen weltweite Änderungen in der Land‐ und Wassernutzung sowie invasive Arten zu rasanten Veränderungen unserer Lebensgemeinschaften. Die Menschheit ist auf vielfältige Weise von diesem Wandel betroffen. Globaler Wandel wird in vielen Ländern zu steigender Armut und politischen Unruhen führen. Die Erforschung der Ursachen und Folgen von Biodiversitäts‐ und Klimaveränderungen und ihre Diskussion in der Gesellschaft stellen eine zentrale Herausforderung dar.
Brieftauben
Authors: Mehlhorn Julia , Rehkämper Gerd 
Published: August 2011

AbstractDas hervorragende Heimfindevermögen von Brieftauben beschäftigt sowohl Wissenschaftler als auch Züchter, die ihre Tiere an Wettflügen teilnehmen lassen. Brieftauben ziehen unter anderem einen Sonnenkompass, das Erdmagnetfeld, Landmarken und Geruchsinformationen zur Heimfindung heran. Auch spielen Erfahrung und Motivation eine große Rolle. Durch die intensive Selektion durch den Menschen hat sich die Brieftaube zu einem Tier entwickelt, welches optimal in seinen Gehirn‐ und Flugleistungen an das Absolvieren unbekannter Strecken angepasst ist. Dies wird vor allem bei den noch heute zahlreich stattfindenden Wettflügen deutlich, bei denen die Tiere zu Höchstleistungen gebracht werden.
Das Weltnaturerbe Wattenmeer in Deutschland ist komplett
Authors: Janke Klaus 
Published: August 2011

AbstractIn seiner jüngsten Sitzung in Paris hat das UNESCO‐Welterbe‐Komitee am 27.06.2011 beschlossen, den Nationalpark Hamburgisches Wattenmeer als Teil des Weltnaturerbes Wattenmeer in die Liste der Welterbestätten der Menschheit einzuschreiben. Damit holt Hamburg seine mit den Niederlanden, Niedersachsen und Schleswig‐Holstein ursprünglich gemeinsam beschlossene Anmeldung nach. Der Nationalpark ist jetzt ein anerkanntes Schutzgebiet von Weltrang und komplettiert zugleich den deutschen Anteil des grenzüberschreitenden Welterbegebietes.
RNA‐Editing in Pflanzen: dem Editor auf der Spur
Authors: Knoop Volker 
Published: August 2011

AbstractVor 20 Jahren wurde RNA‐Editing in Pflanzen entdeckt: Darunter versteht man den gezielten Austausch von Cytidinen zu Uridinen an spezifischen Positionen in den RNAs der Mitochondrien und Chloroplasten. Wie extrem RNA‐Editing in Pflanzen werden kann, zeigen jetzt die mitochondrialen Genome von Bärlappgewächsen mit tausenden solcher Editing‐Stellen. Das Laubmoos Physcomitrella patens hingegen ist besonders arm an RNA‐Editing und damit ein ausgezeichneter Modellorganismus, um den zugrundeliegenden Mechanismen auf die Spur zu kommen.
Molekulare Uhr ohne Gene
Authors: Brennicke Axel 
Published: August 2011

AbstractBei Bakterien, Pflanzen und Tieren ticken innere Uhren in einem Räderwerk von Genen und Proteinen. Da bei diesen Organismen völlig unterschiedliche Moleküle beteiligt sind, ist man bisher von parallelen, unabhängigen Evolutionswegen ausgegangen. Jetzt wurden nicht nur in photosynthetischen Einzellern, sondern auch in den roten Blutkörperchen von Menschen neue Uhren gefunden, die auf reiner Proteinbasis funktionieren. Noch ist nicht ganz klar, ob dies echte Uhrwerke sind oder ob sie Zeiger einer neuen Uhr sind und als Sensoren auf die unterschiedlichen Temperaturen von Tag und Nacht reagieren.
Der High‐Dose‐Hook‐Effekt
Authors: Schrödel Andrea 
Published: August 2011

AbstractQuantitative Analysen, wie beispielsweise die Bestimmung von Tumormarkern (Antigennachweis mittels Immunassay) sind störanfällig und können mit einem Fehler behaftet sein. Neben Fehlbestimmungen durch Kreuzreaktivitäten sollte der Hook‐Effekt nie außer Acht gelassen werden. Durch diesen Effekt können in Immunassays falsch negative Signale erhalten werden, obwohl eine Menge Analyt in der zu vermessenden Probe vorhanden ist. Handelt es sich um einen diagnostischen Test, würde somit der betreffende Patient ein falsch negatives Ergebnis bescheinigt bekommen und sich in trügerischer Sicherheit wiegen. Doch was genau ist eigentlich dieser “Hook‐Effekt”?
Austern – mehr als Luxus
Authors: Seif Abdi Gharib , Kronberg Inge 
Published: August 2011

AbstractBeim Begriff “Austern” denkt der Feinschmecker an “fines de claires” oder “Sylter Royal”, der Ökologe an Karl August Möbius (1825–1908). Er prägte an Austernbeständen der norddeutschen Küste den Begriff “Biozönose” (1877) und wurde damit zum Mitbegründer der Ökologie als Wissenschaft. Inzwischen ist die von ihm untersuchte Europäische Auster (Ostrea edulis) in der Deutschen Bucht verschwunden, Ursachen sind Überfischung und Parasitenbefall. Stattdessen breitet sich die Pazifische Auster Crassostrea gigas im Wattenmeer aus, die aus Aquakulturen entwich. Weltweit nimmt die Dichte natürlich vorkommender Austern an den Küsten ab, was nicht nur ein wirtschaftliches, sondern auch ein ökologisches Problem ist.
Der wirkliche Gerolf Steiner
Authors: Bückmann Detlef 
Published: August 2011

AbstractAn dieser Stelle wurde im Jahr 2006 des Zoologen Harald Stümpke gedacht (BIUZ 2/2006, S. 128). Er hat in lustiger Weise die von Christian Morgenstern erfundene Tiergruppe der Nasobeme zoologisch bearbeitet. Der Name des wirklichen Autors ist nur erwähnt: Gerolf Steiner. War das ein Witzbold? Keinesfalls, sondern ein sensibler, nachdenklich, ja grüblerisch veranlagter Forscher mit dem Blick für Probleme, die sonst nicht gesehen oder die ignoriert werden, und eine der vielschichtigsten Persönlichkeiten der deutschen Biologie im vergangenen Jahrhundert.
Feasibility of transcatheter closure in unselected patients with secundum atrial septal defect, using amplatzer devices and a modified sizing balloon technique
Authors: Kammache Issam , Mancini Julien , Ovaert Caroline , Habib Gilbert , Fraisse Alain 
Published: August 2011

AbstractObjectives: We aimed to assess (1) the role of surgical versus transcatheter closure techniques and (2) the impact of a modified implantation technique to optimize closure of secundum septal defects with the Amplatzer device. Background: Despite several comparative studies, the respective roles of surgical and transcatheter closure are not clarified. Additionally, the impact of modified method of implantation on device closure remains unknown. Methods: Fifty‐seven unselected patients were referred for secundum atrial septal defect closure in 2009, at a median age and weight of 27.5 (0.8–88) years and 40.6 (5.6–97) kg, respectively. Transcatheter closure was attempted in 53 cases under transesophagal echocardiography guidance in children (n = 28) and intracardiac echocardiography guidance in adults. If standard closure failed, a sizing balloon catheter inflated in the left atrium was used as a support to secure the position of the device upon deployment. Results: Fifty of the 57 cases (88%) were successfully closed with a median Amplatzer Septal Occluder size of 20 (10–40) mm, using the sizing balloon technique in eight (16%) cases. No major complication occurred. A trivial residual shunt remained in two patients (4%) whereas a mild mitral regurgitation appeared in one. By univariate analysis, a deficient superior–posterior rim and a large defect (>15 mm2/m2) were associated with the use of the sizing balloon technique (P = 0.04 and 0.03, respectively). A deficient superior–posterior rim and pulmonary hypertension were associated with failure to close the defect (P = 0.02 and 0.03, respectively). Conclusion: The majority of secundum atrial septal defect is amenable to transcatheter closure, using a modified implantation technique in 16% of cases. © 2011 Wiley‐Liss, Inc.
New Molecular Markers for Prostate Tumor Imaging: A Study on 2‐Methylene Substituted Fatty Acids as New AMACR Inhibitors
Authors: Morgenroth Agnieszka , Urusova Elizaveta A. , Dinger Cornelia , Al‐Momani Ehab , Kull Thomas , Glatting Gerhard , Frauendorf Holm , Jahn Olaf , Mottaghy Felix M. , Reske Sven N. , Zlatopolskiy Boris D. 
Published: August 2011

AbstractThe development of prostate carcinoma is associated with alterations in fatty acid metabolism. α‐Methylacyl‐CoA racemase (AMACR) is a peroxisomal and mitochondrial enzyme that catalyses interconversion between the (S)/(R)‐isomers of a range of α‐methylacyl‐CoA thioesters. AMACR is involved in the β‐oxidation of the dietary branched‐chain fatty acids and bile acid intermediates. It is highly expressed in prostate (more than 95 %), colon (92 %), and breast cancers (44 %) but not in the respective normal or hyperplastic tissues. Thus, targeting of AMACR could be a new strategy for molecular imaging and therapy of prostate and some other cancers. Unlabeled 2‐methylenacyl‐CoA thioesters (12 a–c) were designed as AMACR binding ligands. The thioesters were tested for their ability to inhibit the AMACR‐mediated epimerization of (25R)‐THC‐CoA and were found to be strong AMACR inhibitors. Radioiodinated (E)‐131I‐13‐iodo‐2‐methylentridec‐12‐enoic acid (131I‐7 c) demonstrated preferential retention in AMACR‐positive prostate tumor cells (LNCaP, LNCaP C4‐2wt and DU145) compared with both AMACR‐knockout LNCaP C4‐2 AMACR‐siRNA and benign BPH1 prostate cell lines. A significant protein‐bound radioactive fraction with main bands at 47 (sum of molecular weights of AMACR plus 12 c), 70, and 75 kDa was detected in LNCaP C4‐2 wt cells. In contrast, only negligible amounts of protein‐bound radioactivity were found in LNCaP C4‐2 AMACR‐siRNA cells.
Syntheses of Group 4 ansa‐Trovacene Complexes and Conversion of [1]Silatrovacenophanes into Paramagnetic Metallopolymers by Ring‐Opening Polymerization
Authors: Adams Christopher J. , Braunschweig Holger , Fuß Marco , Kraft Katharina , Kupfer Thomas , Manners Ian , Radacki Krzysztof , Whittell George R. 
Published: August 2011

AbstractAn improved protocol for the selective dilithiation of [V(η5‐C5H5)(η7‐C7H7)] has been developed, which afforded [V(η5‐C5H4Li)(η7‐C7H6Li)]⋅PMDTA (5; PMDTA=N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine) in almost quantitative yield (98 %). In the solid state, the species features a dimeric structure with two terminal and two bridging lithium atoms, with the latter connecting both sandwich subunits. Reaction with suitable Group 4 dihalide compounds enabled the isolation of highly strained silicon‐ and germanium‐bridged [1]trovacenophanes 6 and 7. Similarly, reaction of 5 with Cl2Sn2tBu4 afforded the rather unstrained complex [V(η5‐C5H4)(η7‐C7H6)Sn2tBu4] (8), which together with 7 represent the first trovacenophanes to incorporate heavier analogues of silicon in the ansa‐bridge. Ring‐opening polymerization reactions of [V(η5‐C5H4)(η7‐C7H6)SiRR′] (2 a: R=R′=Me; 6: R=Me, R′=iPr) were performed by heating in a solution of toluene in the presence of the Karstedt catalyst, which resulted in the formation of the corresponding soluble poly(trovacenylsilanes) in yields of 41 and 33 %, respectively. As estimated by gel permeation chromatography (GPC), the macromolecules possess molecular weights of Mn=10 010 and 5580 g mol−1 with polydispersity indices of 2.31 and 1.64 for 9 and 10, respectively. ESR spectroscopic studies on 9 and 10 revealed only a single broad resonance in each case without any identifiable 51V hyperfine coupling.
Chemie des Graphens
Authors: Balasubramanian Kannan , Burghard Marko 
Published: August 2011

AbstractEs bedarf noch intensiver Forschung, bis elektronische Bauelemente auf Graphenbasis praktische Anwendung finden. Die Haupthürde besteht darin, verlässliche chemische Verfahren zu finden, mit welchen Graphen strukturiert funktionalisiert werden kann, um lokal eine Bandlücke einzuführen, ohne gleichzeitig Defekte in das Kohlenstoffgitter einzubauen. In dieser Hinsicht kann sicher einiges von der weiter entwickelten Chemie der Kohlenstoff‐Nanoröhren als eindimensionale Gegenstücke des Graphens gelernt werden. Deutlich näher steht hingegen der praktische Einsatz von Graphen in flexiblen, transparenten Elektroden, in (bio‐)chemischen Sensoren oder als Verstärkerkomponente von Werkstoffen. Allerdings setzt die hierfür erforderliche Herstellung größerer Graphenmengen noch nennenswerte Fortschritte in der Überführung von Graphenoxid in reines Graphen voraus. Eine große Herausforderung ist dabei nicht nur die quantitative Entfernung der sauerstoffhaltigen funktionellen Gruppen, sondern auch das Ausheilen von ungeordneten, sp2‐gebundenen Regionen.
Fe(V)‐Nitrid als NH3‐Generator
Authors: Jaenicke Lothar 
Published: August 2011

AbstractSchon seit längerem ist bekannt, dass Koordinationsverbindungen, die Eisenzentren in hohen Oxidationsstufen enthalten, die Funktion von reaktiven Zwischenstufen in der Biokatalyse haben, so z.B. bei der mikrobiellen Stickstoff‐Fixierung durch FeMo‐Nitrogenasen oder der zellulären Oxidation mit Hämkomplexen. Auch für das Haber‐Bosch‐Verfahren wurde bereits vor 20 Jahren von G. Ertl postuliert, dass “Oberflächen‐Nitride” bei dieser Katalyse eine entscheidende Rolle spielen. Daher wurde und wird noch immer nach hochvalenten Eisen‐Nitrido‐Komplexen gesucht, die als biomimetische Modelle in katalytischen Umsetzungen dienen können.
Ozonschicht und Klimawandel
Authors: Welter Kira 
Published: August 2011

AbstractIn diesem Frühjahr warnten Atmosphärenforscher vor einer erhöhten Sonnenbrandgefahr in Europa. Hintergrund waren ungewöhnlich niedrige Ozonwerte über dem Nordpol. In den nächsten Jahren rechnen die Wissenschaftler mit weiteren zeitlich begrenzten, erheblichen Ozonverlusten in der Region. Fast 25 Jahre nach dem Verbot ozonzerstörender Substanzen ist nicht nur der Südpol sondern auch der Nordpol weiterhin von Ozonverlust‐Perioden betroffen. Verantwortlich für den diesjährigen starken Rückgang sind die noch immer in der Luft vorhandenen Fluorchlorkohlenwasserstoffe (FCKW) und Halone, die früher beispielsweise in Sprühdosen oder Feuerlöschern eingesetzt wurden, sowie niedrige Temperaturen in der Stratosphäre der Polarregion. Nun glauben immer mehr Forscher, dass das Schicksal der Ozonschicht außerdem an die Entwicklung des Klimas gekoppelt ist.
Atmospheric Lead in PM2.5 after Leaded Gasoline Phase‐out in Jeddah City, Saudi Arabia
Authors: Aburas Hani M. , Zytoon Mohamed A. , Abdulsalam Mohammed I. 
Published: August 2011

AbstractThe objective of the present study is the assessment of Jeddah ambient air quality in terms of PM2.5, and the associated lead 7 years after phasing out leaded gasoline in Saudi Arabia. Twenty‐four air samples were collected at four locations throughout Jeddah during the period from December 23, 2008 to April 6, 2009. The collected PM2.5‐samples were analyzed by ICP‐MS for determination of lead. The average atmospheric PM2.5 concentration was 50.8 µg/m3. Atmospheric PM2.5‐concentrations were higher than the 24‐h U.S. National Ambient Air Quality Standards (NAAQS) in 14 sample events. The average lead concentration for all samples was 0.07326 µg/m3. Atmospheric lead concentration was dependent on the sampling location. Concentrations at the two southern locations were higher than at the two northern locations. Southern locations had higher lead concentrations due to very high traffic density, in addition to their proximity to industrial zone. In general, the results of this study show a considerable decrease in atmospheric lead concentration 7 years after phasing out leaded gasoline. The study recommends further studies to accurately determine the current sources of atmospheric lead.