bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quadriceps Muscle Function After Exercise in Men and Women With a History of Anterior Cruciate Ligament Reconstruction
Authors: Kuenze Christopher M. , Hertel Jay , Hart Joseph M. 
Published: September 2014

Context :
Sex differences in lower extremity neuromuscular function have been reported after anterior cruciate ligament reconstruction (ACLR). Research evidence supports different levels of fatigability in men and women and between patients with ACLR and healthy controls. The influence of sex on the response to continuous exercise in patients with ACLR is not clear.

Objective :
To compare quadriceps neuromuscular function after exercise between men and women with ACLR.

Design :
Descriptive laboratory study.

Setting :
Laboratory.

Patients or Other Participants :
Twenty-six active volunteers (13 men [50%]: age = 24.1 ± 4.4 years, height = 179.1 ± 9.8 cm, mass = 80.1 ± 9.4 kg, months since surgery = 43.5 ± 37.0; 13 women [50%]: age = 24.2 ± 5.6 years, height = 163.0 ± 5.9 cm, mass = 62.3 ± 8.3 kg, months since surgery = 45.8 ± 42.7) with a history of unilateral primary ACLR at least 6 months earlier.

Intervention(s) :
Thirty minutes of continuous exercise comprising 5 separate 6-minute cycles, including 5 minutes of uphill walking and 1 minute of body-weight squatting and step-ups.

Main Outcome Measure(s) :
Normalized knee-extension maximal voluntary isometric contraction torque, quadriceps superimposed-burst torque, and quadriceps central activation ratio before and after exercise. We performed separate 2 (sex: men, women) × 2 (time: preexercise, postexercise) repeated-measures analyses of variance for the 3 variables. Separate, independent-samples t tests were calculated to compare preexercise with postexercise change in all dependent variables between sexes.

Results :
A significant group-by-time interaction was present for knee-extension torque (P = .04). The percentage reduction in knee-extension maximal voluntary isometric contraction torque (men = 1.94%, women = −10.32%; P = .02) and quadriceps central activation ratio (men = −1.45%, women = −8.69%; P = .03) experienced by men was less than that observed in women.

Conclusions :
In the presence of quadriceps dysfunction, female participants experienced greater-magnitude reductions in quadriceps function after 30 minutes of exercise than male participants. This indicates a reduced ability to absorb knee-joint loads, which may have significant implications for reinjury and joint osteoarthritis in women after ACLR.
Potential drivers of sinking particle's size spectra and vertical flux of particulate organic carbon (POC): Turbulence, phytoplankton, and zooplankton
Authors: Wiedmann Ingrid , Reigstad Marit , Sundfjord Arild , Basedow Sünnje 
Published: September 2014

AbstractPhytoplankton spring blooms in temperate and high‐latitude shelf seas are commonly associated with an enhanced particulate organic carbon (POC) export of aggregates from the euphotic zone. In contrast, a postbloom situation is usually linked to a predominant POC retention, where small cells (<10 μm) and strong grazing pressure prevail. This study aimed to examine impacts of turbulence, phytoplankton, bloom stage, and zooplankton abundance on the sinking particles' size spectra and POC flux to improve the understanding of the downward flux mechanisms in the upper 100 m. We deployed sediment traps, partly modified with gel jars, at four depths along a stratification and phytoplankton bloom gradient in the Barents Sea, an Arctic shelf sea. The highest POC export (60 m: 923 mg C m−2 d−1) was found in deep‐mixed, postbloom Atlantic influenced waters, despite the high grazer abundance (12,000 individuals m−3). Particle size spectra indicated that this flux was dominated by particles of 0.05–1.00 mm equivalent spherical diameter (ESDimage) with a POC:volume ratio matching copepod fecal pellets. Large particles (0.5–2.8 mm ESDimage) dominated the flux at a stratified, late peak bloom station in Arctic Waters and a stratified, late bloom situation at the Polar Front, but with lower POC:volume ratio and POC flux (60 m: <823 mg C m−2 d−1). Accordingly, a high POC flux at the base of the euphotic zone is not necessarily driven by large phytoplankton aggregates, but can also occur during a postbloom situation in form of small fecal pellet fragments with high POC content.
A ventilation‐based framework to explain the regeneration‐scavenging balance of iron in the ocean
Authors: Tagliabue Alessandro , Williams Richard G. , Rogan Nicholas , Achterberg Eric P. , Boyd Philip W. 
Published: September 2014

AbstractOur understanding of the processes driving the patterns of dissolved iron (DFe) in the ocean interior, either in observations or models, is complicated by the combined influences of subduction from the surface mixed layer, notable subsurface sources, regeneration, and scavenging loss. We describe a ventilation‐based framework to quantify these processes in a global ocean biogeochemical model including diagnostics along potential density surfaces. There is a prevailing control of subsurface DFe by the subduction of surface DFe as preformed DFe augmented by benthic sources of DFe from hydrothermal activity and sediments. Unlike phosphate, there is often a first‐order balance with a near cancelation between regeneration and scavenging with the remaining “net regeneration” controlled by the ventilation of surface excesses in Fe‐binding ligands. This DFe framework provides a more stringent test of how the total DFe distribution is mechanistically controlled within a model and may be subsequently used to interpret observed DFe distributions.
Spark Plasma Sintering and Characterization of Graphene Platelet/Ceramic Composites
Authors: Jiang Kyle , Li Jiran , Liu Jian 
Published: September 2014

AbstractThis paper reports a study on sintering and characterization of graphene platelet (GPL)‐reinforced ceramic composites. Alumina (Al2O3) and zirconia (ZrO2) toughened Al2O3 (ZTA) composites reinforced with GPLs are fabricated, respectively, using spark plasma sintering. The microstructures and mechanical properties of the sintered samples are investigated. It is found that the addition of GPLs hinders the growth of the ceramic matrix grains and help form homogenous microstructures of the ceramic matrices. Agglomeration of GPLs occurs during the fabrication process and formation of GPL aggregates is impeded when ceramic powders of smaller particle size and a shorter milling process are used. Fracture toughness of the ceramic matrices is significantly improved by introducing GPLs. Approximately, a 26.4% and a 29% improvements in fracture toughness are achieved for GPL/Al2O3 and GPL/ZTA composites, respectively. The main toughening mechanisms induced by GPLs are pull‐out and crack bridging.
Definition of 5q11.2 microdeletion syndrome reveals overlap with CHARGE syndrome and 22q11 deletion syndrome phenotypes
Authors: Snijders Blok Charlotte , Corsten‐Janssen Nicole , FitzPatrick David R. , Romano Corrado , Fichera Marco , Vitello Girolamo Aurelio , Willemsen Marjolein H. , Schoots Jeroen , Pfundt Rolph , van Ravenswaaij‐Arts Conny M.A. , Hoefsloot Lies , Kleefstra Tjitske 
Published: September 2014

AbstractMicrodeletions of the 5q11.2 region are rare; in literature only two patients with a deletion in this region have been reported so far. In this study, we describe four additional patients and further define this new 5q11.2 microdeletion syndrome. A comparison of the features observed in all six patients with overlapping 5q11.2 deletions showed a phenotypic spectrum that overlaps with CHARGE syndrome and 22q11.2 deletion syndrome including choanal atresia, developmental delay, heart defects, external ear abnormalities, and short stature. No colobomas or abnormalities of semicircular canals and olfactory nerves were reported. Two male patients had genital abnormalities. We estimated a 2.0 Mb (53.0–55.0 Mb) Shortest Region of Overlap (SRO) for the main clinical characteristics of the syndrome. This region contains nine genes and two non‐coding microRNAs. In this region DHX29 serves as the candidate gene as it encodes an ATP‐dependent RNA‐helicase that is involved in the initiation of RNA translation. Screening a small cohort of 14 patients who presented the main features, however, did not reveal any pathogenic abnormalities of DHX29. © 2014 Wiley Periodicals, Inc.
Metallkatalysierte desalkoxylierende CAr‐C‐Kreuzkupplung – Austausch aromatischer Methoxygruppen von Arylethern unter Verwendung eines funktionalisierten Nukleophils
Authors: Leiendecker Matthias , Hsiao Chien‐Chi , Guo Lin , Alandini Nurtalya , Rueping Magnus 
Published: September 2014

AbstractDer direkte Austausch aromatischer Methoxygruppen mit einem aktivierten Kohlenstoffatom würde neue Wege für gezielte und diversitätsorientierte Synthesen bahnen. Wir zeigen hier, dass solche Reaktionen in einem Schritt mit einem difunktionellen Nukleophil und einem CAr‐OMe‐bindungsspaltenden Katalysator ablaufen können. Die gebildeten Produkte sind stabil, α‐CH‐aktiv und für diverse weitere Modifikationen geeignet.
RNA Interference Controlled by Light of Variable Wavelength
Authors: Meyer Andreas , Mokhir Andriy 
Published: September 2014

AbstractKnown molecular, “caged” siRNAs are activated by UV light. Since the light of this type is toxic to cells, the uncaging can cause undesired side effects. A modular, molecular system for designing siRNAs is reported, which can be activated by non‐toxic light in live cells. For example, siRNAs responsive to green and red light are described. The uncaging is mediated by 1O2 photogenerated on a photosensitizer, which is attached to the 3′‐terminus of the lagging strand. The 5′‐terminus of the guide strand is alkylated (“caged”) with a 9‐anthracenyl residue. The latter fragment reacts with the 1O2 with formation of the free (uncaged) 5′‐OH terminus. Simultaneously with the uncaging the photosensitizer is bleached and no more 1O2 is generated after this process is completed. The photoactivation of the siRNAs described here is not toxic to cells.
Bildung und Umlagerung von Homoserin‐Depsipeptiden und ‐proteinen durch α‐Ketosäure‐Hydroxylamin‐Ligation mit 5‐Oxaprolin
Authors: Wucherpfennig Thomas G. , Rohrbacher Florian , Pattabiraman Vijaya R. , Bode Jeffrey W. 
Published: September 2014

AbstractDie Hauptprodukte der chemischen Ligation von α‐Ketosäuren und 5‐Oxaprolin sind Ester und nicht – wie zuvor berichtet – Amide. Durch die schnell ablaufende Umlagerung in basischen Puffern lässt sich das Depsipeptidprodukt in das Amid überführen. Die Esterbildung ermöglicht Rückschlüsse auf den möglichen Mechanismus von Typ‐II‐KAHA‐Ligationen und eröffnet einen Weg zur chemischen Synthese von Depsiproteinen.
Catalytic Wittig Reactions of Semi‐ and Nonstabilized Ylides Enabled by Ylide Tuning
Authors: Coyle Emma E. , Doonan Bryan J. , Holohan Andrew J. , Walsh Killian A. , Lavigne Florie , Krenske Elizabeth H. , O'Brien Christopher J. 
Published: September 2014

AbstractThe first examples of catalytic Wittig reactions with semistabilized and nonstabilized ylides are reported. These reactions were enabled by utilization of a masked base, sodiumtert‐butyl carbonate, and/or ylide tuning. The acidity of the ylide‐forming proton was tuned by varying the electron density at the phosphorus center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement ofE selectivity up to >95:5,E/Z.
Photo‐Organocatalysis of Atom‐Transfer Radical Additions to Alkenes
Authors: Arceo Elena , Montroni Elisa , Melchiorre Paolo 
Published: September 2014

AbstractWe have found that an organic molecule as simple as p‐anisaldehyde efficiently catalyzes the intermolecular atom‐transfer radical addition (ATRA) of a variety of haloalkanes onto olefins, one of the fundamental carbon–carbon bond‐forming transformations in organic chemistry. The reaction requires exceptionally mild reaction conditions to proceed, as it occurs at ambient temperature and under illumination by a readily available fluorescent light bulb. Initial investigations support a mechanism whereby the aldehydic catalyst photochemically generates the reactive radical species by sensitization of the organic halides by an energy‐transfer pathway.
Ein Metall‐organisches Netzwerk auf Basis von Cu‐Adatom‐ Trimeren
Authors: Bebensee Fabian , Svane Katrine , Bombis Christian , Masini Federico , Klyatskaya Svetlana , Besenbacher Flemming , Ruben Mario , Hammer Bjørk , Linderoth Trolle R. 
Published: September 2014

AbstractMittels Koadsorption von Metallatomen und organischen Liganden hergestellte Koordinationsnetzwerke haben interessante Eigenschaften, z. B. in der Katalyse oder für die Datenspeicherung. Bisher basierten solche Oberflächen‐Netzwerke auf Koordination an einzelnen Metallatomen. Hier beschreiben wir hingegen die Bildung eines neuartigen Metall‐organischen Netzwerkes, das auf Kupfertrimeren als Noden basiert. Dieses Netzwerk entsteht nach dem Aufdampfen und anschließendem Heizen von Tetrahydroxybenzol (THB) auf Cu(111) im Ultrahochvakuum. Mittels STM, XPS und DFT‐Rechnungen konnte gezeigt werden, dass bei einer Temperatur von 440 K alle vier Hydroxygruppen des THB dehydriert werden. Der dabei entstehende, hochreaktive Ligand bindet anschließend an Cu‐Trimere, die in hochaufgelösten STM‐Aufnahmen sichtbar sind. Mit den gleichmäßig angeordneten und monodispersen Cu‐Trimeren stellt das hier vorgestellte Netzwerk ein zweidimensionales Analogon zu Metall‐organischen Gerüsten dar, die in der Regel ebenfalls komplexere Noden als einzelne Metallatome aufweisen.
Aktivatoren des molekularen Chaperons Hsp90 erleichtern geschwindigkeitsbestimmende Konformationsänderungen
Authors: Zierer Bettina K. , Weiwad Matthias , Rübbelke Martin , Freiburger Lee , Fischer Gunter , Lorenz Oliver R. , Sattler Michael , Richter Klaus , Buchner Johannes 
Published: September 2014

AbstractDer Reaktionszyklus des molekularen Chaperons Hsp90 ist durch ATP‐getriebene Konformationsänderungen charakterisiert, die der ATP‐Hydrolyse vorgeschaltet sind. Es gibt bereits niedermolekulare Inhibitoren von Hsp90, die mit der ATP‐Bindung konkurrieren. Wir fragten uns, ob Verbindungen existieren, die den konformationellen Zyklus beschleunigen können. In einem FRET‐basierten Screen, der Konformationsänderungen in Hsp90 detektiert, identifizierten wir zwei Verbindungen und analysierten ihre Wirkungsweise. Wir können zeigen, dass die intrinsische Inhibition von Hsp90, welche konformationelle Umlagerungen verhindert, durch diese Substanzen überwunden wird. Diese Wirkungsweise ähnelt der des Cochaperons Aha1 von Hsp90, das die ATPase‐Aktivität beschleunigt. Während beide Verbindungen Konformationsänderungen beeinflussen, so steuern sie jeweils verschiedene Aspekte der Strukturübergänge. Zudem unterscheiden sich ihre durch NMR‐Spektroskopie bestimmten Bindestellen. Unsere Studie zeigt, dass kleine Moleküle in der Lage sind, spezifische geschwindigkeitsbestimmende Übergänge in Hsp90 in ähnlicher Weise zu beschleunigen wie dies durch Protein‐Cofaktoren geschieht.
Superbenzol‐Porphyrin‐Konjugate
Authors: Lungerich Dominik , Hitzenberger Jakob F. , Marcia Mario , Hampel Frank , Drewello Thomas , Jux Norbert 
Published: September 2014

AbstractEin nichtmetalliertes Porphyrin mit zwei trans‐ständigen Hexabenzocoronen(HBC)‐Substituenten und der zugehörige Zinkkomplex wurden hergestellt. Die Verbindungen wurden ausführlich untersucht, und es zeigte sich, dass sie in der Gasphase trikationische Dimere bilden. Die Röntgenstrukturanalyse des Zinkkomplexes ergab eine ausgeprägte π‐Stapelwechselwirkung, wohingegen beim nichtmetallierten Porphyrin n‐Heptan interkaliert, was die π‐Stapelung weitgehend verhindert. Die Anregung der HBC‐Substituenten führt zu einem effizienten Energietransfer zum Porphyrinkern.
Single‐Site Copper(II) Water Oxidation Electrocatalysis: Rate Enhancements with HPO42− as a Proton Acceptor at pH 8
Authors: Coggins Michael K. , Zhang Ming‐Tian , Chen Zuofeng , Song Na , Meyer Thomas J. 
Published: September 2014

AbstractThe complex CuII(Py3P) (1) is an electrocatalyst for water oxidation to dioxygen in H2PO4−/HPO42− buffered aqueous solutions. Controlled potential electrolysis experiments with 1 at pH 8.0 at an applied potential of 1.40 V versus the normal hydrogen electrode resulted in the formation of dioxygen (84 % Faradaic yield) through multiple catalyst turnovers with minimal catalyst deactivation. The results of an electrochemical kinetics study point to a single‐site mechanism for water oxidation catalysis with involvement of phosphate buffer anions either through atom–proton transfer in a rate‐limiting OO bond‐forming step with HPO42− as the acceptor base or by concerted electron–proton transfer with electron transfer to the electrode and proton transfer to the HPO42− base.
Theranostic Iridium(III) Complexes as One‐ and Two‐Photon Phosphorescent Trackers to Monitor Autophagic Lysosomes
Authors: He Liang , Tan Cai‐Ping , Ye Rui‐Rong , Zhao Yi‐Zhi , Liu Ya‐Hong , Zhao Qiang , Ji Liang‐Nian , Mao Zong‐Wan 
Published: September 2014

AbstractDuring autophagy, the intracellular components are captured in autophagosomes and delivered to lysosomes for degradation and recycling. Changes in lysosomal trafficking and contents are key events in the regulation of autophagy, which has been implicated in many physiological and pathological processes. In this work, two iridium(III) complexes (LysoIr1 and LysoIr2) are developed as theranostic agents to monitor autophagic lysosomes. These complexes display lysosome‐activated phosphorescence and can specifically label lysosomes with high photostability. Simultaneously, they can induce autophagy potently without initiating an apoptosis response. We demonstrate that LysoIr2 can effectively implement two functions, namely autophagy induction and lysosomal tracking, in the visualization of autophagosomal–lysosomal fusion. More importantly, they display strong two‐photon excited fluorescence (TPEF), which is favorable for live cell imaging and in vivo applications.
MoS2 Nanoflowers with Expanded Interlayers as High‐Performance Anodes for Sodium‐Ion Batteries
Authors: Hu Zhe , Wang Lixiu , Zhang Kai , Wang Jianbin , Cheng Fangyi , Tao Zhanliang , Chen Jun 
Published: September 2014

AbstractMoS2 nanoflowers with expanded interlayer spacing of the (002) plane were synthesized and used as high‐performance anode in Na‐ion batteries. By controlling the cut‐off voltage to the range of 0.4–3 V, an intercalation mechanism rather than a conversion reaction is taking place. The MoS2 nanoflower electrode shows high discharge capacities of 350 mAh g−1 at 0.05 A g−1, 300 mAh g−1 at 1 A g−1, and 195 mAh g−1 at 10 A g−1. An initial capacity increase with cycling is caused by peeling off MoS2 layers, which produces more active sites for Na+ storage. The stripping of MoS2 layers occurring in charge/discharge cycling contributes to the enhanced kinetics and low energy barrier for the intercalation of Na+ ions. The electrochemical reaction is mainly controlled by the capacitive process, which facilitates the high‐rate capability. Therefore, MoS2 nanoflowers with expanded interlayers hold promise for rechargeable Na‐ion batteries.
Functionalization of P4 Using a Lewis Acid Stabilized Bicyclo[1.1.0]tetraphosphabutane Anion
Authors: Borger Jaap E. , Ehlers Andreas W. , Lutz Martin , Slootweg J. Chris , Lammertsma Koop 
Published: September 2014

AbstractReacting white phosphorus (P4) with sterically encumbered aryl lithium reagents (aryl=2,6‐dimesitylphenyl or 2,4,6‐tBu3C6H2) and B(C6F5)3 gives the unique, isolable Lewis acid stabilized bicyclo[1.1.0]tetraphosphabutane anion. Subsequent alkylation of the nucleophilic site of the RP4 anion gives access to non‐symmetrical disubstituted bicyclic tetraphosphorus compounds. This novel method enables PC bond formation in a controlled fashion using white phosphorus as starting material.
A Surface Coordination Network Based on Copper Adatom Trimers
Authors: Bebensee Fabian , Svane Katrine , Bombis Christian , Masini Federico , Klyatskaya Svetlana , Besenbacher Flemming , Ruben Mario , Hammer Bjørk , Linderoth Trolle R. 
Published: September 2014

AbstractSurface coordination networks formed by co‐adsorption of metal atoms and organic ligands have interesting properties, for example regarding catalysis and data storage. Surface coordination networks studied to date have typically been based on single metal atom centers. The formation of a novel surface coordination network is now demonstrated that is based on network nodes in the form of clusters consisting of three Cu adatoms. The network forms by deposition of tetrahydroxybenzene (THB) on Cu(111) under UHV conditions. As shown from a combination of scanning tunneling microscopy, X‐ray photoelectron spectroscopy, and density functional theory calculations, all four hydroxy groups of THB dehydrogenate upon thermal activation at 440 K. This highly reactive ligand binds to Cu adatom trimers, which are resolved by high‐resolution STM. The network creates an ordered array of mono‐dispersed metal clusters constituting a two‐dimensional analogue of metal–organic frameworks.
Developing Phospha‐Stork Chemistry Induced by a Borane Lewis Acid
Authors: Hasegawa Yasuharu , Daniliuc Constantin G. , Kehr Gerald , Erker Gerhard 
Published: September 2014

AbstractBulky vinyl phosphanes undergo carbon–carbon coupling with aryl aldehydes with the help of the Lewis acid B(C6F5)3to give isolable methylene phosphonium products. Dimesityl(vinyl)phosphane undergoes a phospha‐Stork reaction with bulky enones efficiently catalyzed by B(C6F5)3to eventually yield the corresponding substituted cyclobutane products.
Artificial Accelerators of the Molecular Chaperone Hsp90 Facilitate Rate‐Limiting Conformational Transitions
Authors: Zierer Bettina K. , Weiwad Matthias , Rübbelke Martin , Freiburger Lee , Fischer Gunter , Lorenz Oliver R. , Sattler Michael , Richter Klaus , Buchner Johannes 
Published: September 2014

AbstractThe molecular chaperone Hsp90 undergoes an ATP‐driven cycle of conformational changes in which large structural rearrangements precede ATP hydrolysis. Well‐established small‐molecule inhibitors of Hsp90 compete with ATP‐binding. We wondered whether compounds exist that can accelerate the conformational cycle. In a FRET‐based screen reporting on conformational rearrangements in Hsp90 we identified compounds. We elucidated their mode of action and showed that they can overcome the intrinsic inhibition in Hsp90 which prevents these rearrangements. The mode of action is similar to that of the co‐chaperone Aha1 which accelerates the Hsp90 ATPase. However, while the two identified compounds influence conformational changes, they target different aspects of the structural transitions. Also, the binding site determined by NMR spectroscopy is distinct. This study demonstrates that small molecules are capable of triggering specific rate‐limiting transitions in Hsp90 by mechanisms similar to those in protein cofactors.
[2+2] Photocycloaddition of 3‐Alkenyloxy‐2‐cycloalkenones: Enantioselective Lewis Acid Catalysis and Ring Expansion
Authors: Brimioulle Richard , Bach Thorsten 
Published: September 2014

AbstractBy application of substoichiometric amounts (50 mol %) of a chiral Lewis acid, the intramolecular [2+2] photocycloaddition of the title compounds was achieved with high enantioselectivity (up to 94 % ee). Upon cleavage of the cyclobutane ring the resulting tricyclic products underwent ring‐expansion reactions under acidic conditions and formed anellated seven‐ or eight‐membered‐ring systems without racemization. The ring expansion could be combined with a diastereoselective reduction (triethylsilane) or allylation (allyltrimethylsilane) upon BF3 catalysis (48–87 % yield).