bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraskeletal osteosarcoma: An uncommon variant with rare metastatic sites detected with FDG PET/CT
Authors: Puranik Ameya D. , Purandare Nilendu C. , Bal Munita M. , Shah Sneha , Agrawal Archi , Rangarajan Venkatesh 
Published: June 2014

AbstractExtraskeletal osteosarcoma (ESOS) is a rare malignancy, which commonly presents with metastatic disease. Like their osteogenic counterparts, these tumors commonly metastasize to lungs and bones. We report the fluoro-deoxyglucose positron emission tomography findings in a case of ESOS presenting with a combination of rare metastatic sites such as brain, kidney and the bone marrow.
Arguing for the Immortality of the Soul in the Palinode of thePhaedrus
Authors: Moore Christopher 
Published: June 2014

ABSTRACTThis article argues that in his second speech of the Phaedrus (the “palinode”), Socrates gives an intentionally fallacious argument. He gives this argument, starting “all/every soul is immortal” (245c6–246a2), to show his speech-loving friend Phaedrus how—rather than simply to tell him that—analytic as much as imagistic speech can persuade without deserving conviction. This argument joins four others that recent Phaedrus scholarship has shown to be deliberately misconstructed. The entire dialogue has Socrates demonstrating to Phaedrus that the proper attitude to speech is active and critical scrutiny. “Philosophy”—toward which Socrates wants to turn Phaedrus—is not the rhetorical mode “speaking in sequential inferences” but is instead a kind of shared listening and conversation, an association committed to “making a person most thoughtful.” Yet inducting someone into philosophy still depends on some rhetorical mode: the kind that reveals a person's need for a commitment to investigation.
Numerical modeling of erosional and depositional bank processes in migrating river bends with self‐formed width: Morphodynamics of bar push and bank pull
Authors: Eke Esther , Parker Gary , Shimizu Yasuyuki 
Published: June 2014

AbstractMeandering rivers display active communication between bank erosion and bar deposition processes. How does this occur? How does the river select its width? To answer these questions, we implement a model for meander migration where both bank processes (erosion and deposition) are considered independently. Bank erosion is modeled as erosion of purely noncohesive bank material damped by natural slump block armoring; channel deposition is modeled via flow‐retarded vegetal encroachment. Both processes are tied to a slope‐dependent channel forming Shields number; banks with near‐bank Shields number below this value undergo deposition, and those above it undergo erosion. Channel‐forming Shields number must increase with slope, as dictated by available data and model performance. Straight channel modeling shows that a channel arrives at an equilibrium width from any initial condition. For the channel bend, the river always approaches an asymptotic state where width reduces slowly in time and where bank erosion and deposition occur at nearly equal rates. Before this state is reached, however, the river follows a phase‐plane trajectory with four possible regimes: (a) both banks erode, (b) both banks deposit, (c) both banks migrate outward, but with a faster depositing bank (bar push), and (d) both banks migrate outward, but with a faster eroding bank (bank pull). The trajectory of migration on the phase plane depends on initial conditions and input parameters controlling the rate of depositional and erosional migration. All input parameters have specific physical meaning, and the potential to be measured in the field.
What does CloudSat reveal about global land precipitation detection by other spaceborne sensors?
Authors: Behrangi Ali , Tian Yudong , Lambrigtsen Bjorn H. , Stephens Graeme L. 
Published: May 2014

AbstractCurrent orbital land precipitation products have serious shortcomings in detecting light rain and snowfall, the most frequent types of global precipitation. The missed precipitation is then propagated into the merged precipitation products that are widely used. Precipitation characteristics such as frequency and intensity and their regional distribution are expected to change in a warming climate. It is important to accurately capture those characteristics to understand and model the current state of the Earth's climate and predict future changes. In this work, the precipitation detection performance of a suite of precipitation sensors, commonly used in generating the merged precipitation products, are investigated. The high sensitivity of CloudSat Cloud Profiling Radar (CPR) to liquid and frozen hydrometeors enables superior estimates of light rainfall and snowfall within 80°S–80°N. Three years (2007–2009) of CloudSat precipitation data were collected to construct a climatology reference for guiding our analysis. In addition, auxiliary data such as infrared brightness temperature, surface air temperature, and cloud types were used for a more detailed assessment. The analysis shows that no more than 50% of the tropical (40°S–40°N) precipitation occurrence is captured by the current suite of precipitation measuring sensors. Poleward of 50° latitude, a combination of various factors such as an abundance of light rainfall, snowfall, shallow precipitation‐bearing clouds, and frozen surfaces reduces the space‐based precipitation detection rate to less than 20%. This shows that for a better understanding of precipitation from space, especially at higher latitudes, there is a critical need to improve current precipitation retrieval techniques and sensors.
Physical properties of ambient and laboratory‐generated secondary organic aerosol
Authors: O'Brien Rachel E. , Neu Alexander , Epstein Scott A. , MacMillan Amanda C. , Wang Bingbing , Kelly Stephen T. , Nizkorodov Sergey A. , Laskin Alexander , Moffet Ryan C. , Gilles Mary K. 
Published: June 2014

AbstractThe size and thickness of organic aerosol particles collected by impaction in five field campaigns were compared to those of laboratory‐generated secondary organic aerosols (SOA). Scanning transmission X‐ray microscopy was used to measure the total carbon absorbance (TCA) by individual particles as a function of their projection areas on the substrate. Particles with higher viscosity/surface tension can be identified by a steeper slope on a plot of TCA versus size because they flatten less upon impaction. The slopes of the ambient data are statistically similar indicating a small range of average viscosities/surface tensions across five field campaigns. Steeper slopes were observed for the plots corresponding to ambient particles, while smaller slopes were indicative of the laboratory‐generated SOA. This comparison indicates that ambient organic particles have higher viscosities/surface tensions than those typically generated in laboratory SOA studies.
Visualisierung von Maustumoren mit einem lipidierten Cathepsin‐S‐Substrat
Authors: Hu Hai‐Yu , Vats Divya , Vizovisek Matej , Kramer Lovro , Germanier Catherine , Wendt K. Ulrich , Rudin Markus , Turk Boris , Plettenburg Oliver , Schultz Carsten 
Published: May 2014

AbstractDie Synthese und Anwendung zweier für Cathepsin S spezifischer Sonden wird beschrieben. Um den langfristigen Verbleib der Sonden am Zielort und eine hohes Signal/Rausch‐Verhältnis zu erzielen, wurde ein Lipidierungsansatz über das Einfügen eines Palmitinsäurerestes eingesetzt. Nach Cathepsin‐S‐induzierter Spaltung in Zellen und im transplantierten Tumormausmodell stieg die Fluoreszenz durch Entlöschen stark an, und wir beobachteten eine intrazelluläre Anreicherung der Fluoreszenz im Tumorgewebe. Im Vergleich zur nichtlipidierten Sonde lieferte die lipidierte Sonde ein anhaltendes starkes Fluoreszenzsignal im Tumor. Dies zeigt, dass nichtinvasive Tumoridentifikation per Fluoreszenz möglich ist. Das Prinzip der Lipidierungs‐vermittelten Verabreichung kann potenziell auch auf zytotoxische Verbindungen erweitert werden, um Tumormasse zu reduzieren.
Coordination and Redox Isomerization in the Reduction of a Uranium(III) Monoarene Complex
Authors: La Pierre Henry S. , Kameo Hajime , Halter Dominik P. , Heinemann Frank W. , Meyer Karsten 
Published: May 2014

AbstractSynthetic studies on the redox chemistry of trivalent uranium monoarene complexes were undertaken with a complex derived from the chelating tris(aryloxide)arene ligand (Ad,MeArO)3mes3−. Cyclic voltammetry of [{(Ad,MeArO)3mes}UIII] (1) revealed a nearly reversible and chemically accessible reduction at −2.495 V vs. Fc/Fc+—the first electrochemical evidence for a formally divalent uranium complex. Chemical reduction of 1 indicates that reduction induces coordination and redox isomerization to form a uranium(IV) hydride, and addition of a crown ether results in hydride insertion into the coordinated arene to afford uranium(IV) complexes. This stoichiometric reaction sequence provides structural insight into the mechanism of arene functionalization at diuranium inverted sandwich complexes.
Synthesis and Characterization of a Uranium(II) Monoarene Complex Supported by δ Backbonding
Authors: La Pierre Henry S. , Scheurer Andreas , Heinemann Frank W. , Hieringer Wolfgang , Meyer Karsten 
Published: May 2014

AbstractThe low‐temperature (<−35 °C) reduction of the trivalent uranium monoarene complex [{(Ad,MeArO)3mes}U] (1), with potassium spheres in the presence of a slight excess of 2.2.2‐cryptand, affords the quantitative conversion of 1 into the uranium(II) monoarene complex [K(2.2.2‐crypt)][((Ad,MeArO)3mes)U] (1‐K). The molecular and electronic structure of 1‐K was established experimentally by single‐crystal X‐ray diffraction, variable‐temperature 1H NMR and X‐band EPR spectroscopy, solution‐state and solid‐state magnetism studies, and optical absorption spectroscopy. The electronic structure of the complex was further investigated by DFT calculations. The complete body of evidence confirms that 1‐K is a uranium(II) monoarene complex with a 5f 4 electronic configuration supported by δ backbonding and that the nearly reversible, room‐temperature reduction observed for 1 at −2.495 V vs. Fc/Fc+ is principally metal‐centered.
Thermally Driven Polymorphic Transition Prompting a Naked‐Eye‐Detectable Bending and Straightening Motion of Single Crystals
Authors: Shima Tatsuya , Muraoka Takahiro , Hoshino Norihisa , Akutagawa Tomoyuki , Kobayashi Yuka , Kinbara Kazushi 
Published: May 2014

AbstractThe amplification of molecular motions so that they can be detected by the naked eye (107‐fold amplification from the ångström to the millimeter scale) is a challenging issue in the development of mechanical molecular devices. In this context, the perfectly ordered molecular alignment of the crystalline phase has advantages, as demonstrated by the macroscale mechanical motions of single crystals upon the photochemical transformation of molecules. In the course of our studies on thermoresponsive amphiphiles containing tetra(ethylene glycol) (TEG) moieties, we serendipitously found that thermal conformational changes of TEG units trigger a single‐crystal‐to‐single‐crystal polymorphic phase transition. The single crystal of the amphiphile undergoes bending and straightening motion during both heating and cooling processes at the phase‐transition temperatures. Thus, the thermally triggered conformational change of PEG units may have the advantage of inducing mechanical motion in bulk materials.
A 3D Aluminoborate Open Framework Interpenetrated by 2D Zinc–Amine Coordination‐Polymer Networks in Its 11‐Ring Channels
Authors: Wei Li , Wei Qi , Lin Zhi‐En , Meng Qin , He Huan , Yang Bai‐Feng , Yang Guo‐Yu 
Published: May 2014

AbstractA new inorganic–organic hybrid solid, [Zn(dap)2][AlB5O10], combining the structural features of 3D open‐framework inorganic solids and 2D metal–organic coordination polymers has been synthesized under solvothermal conditions. The compound displays extensive luminescence and moderate second‐harmonic‐generation efficiency.
A Bioinspired Catalytic Oxygenase Cascade to Generate Complex Oxindoles
Authors: Wang Yao , Bauer Jonathan O. , Strohmann Carsten , Kumar Kamal 
Published: May 2014

AbstractCatalytic, selective, and controlled oxidative functionalization of CH bonds using molecular oxygen as an oxidant remains highly desirable and equally challenging in the development of synthetic methodologies. Presented herein is a one‐pot oxygenase cascade reaction wherein a copper(I)‐catalyzed oxygenase reaction transforms the allylic methyl group in 3‐methylidene oxindoles into an aldehyde, which then undergoes an aldol–oxa‐Michael addition sequence with β‐ketoesters to yield dihydrofuran‐bearing oxindoles.
Substratinduzierte Konformationsänderungen in Klasse‐I‐Terpencyclasen
Authors: Baer Philipp , Rabe Patrick , Fischer Katrin , Citron Christian A. , Klapschinski Tim A. , Groll Michael , Dickschat Jeroen S. 
Published: May 2014

AbstractWir präsentieren kristallographische und funktionelle Daten einer Selina‐4(15),7(11)‐dien‐Synthase (SdS) aus Streptomyces pristinaespiralis in offener und geschlossener (Ligand‐gebundener) Konformation. Durch Analyse einer Substrat‐induzierten Konformationsänderung des G1/2‐Helixbruchmotivs wurde ein Induced‐Fit‐Mechanismus identifiziert. Diese Konformationsänderung hebt eine bis dahin unbeschriebene Effektortriade, bestehend aus dem Pyrophosphat‐Sensor Arg178, dem Linker Asp181 und dem Effektor Gly182‐O, hervor. Dieses Strukturmotiv ist hoch konserviert in Klasse‐I‐Terpencyclasen von Bakterien, Pilzen und Pflanzen, einschließlich der epi‐Isozizaen‐Synthase (3KB9), der Aristolochen‐Synthase (4KUX), der Bornyldiphosphat‐Synthase (1N20), der Limonen‐Synthase (2ONG), der 5‐epi‐Aristolochen‐Synthase (5EAT) und der Taxa‐4(5),11(12)‐dien‐Synthase (3P5R). Strukturbasierte Mutageneseexperimente in Kombination mit der Analyse der Produktspektren stützen die mechanistischen Modelle der Carbokationbildung und ‐stabilisierung in der SdS.
Palladium‐Catalyzed Insertion of an Allene into an Aminal: Aminomethylamination of Allenes by CN Bond Activation
Authors: Hu Jianhua , Xie Yinjun , Huang Hanmin 
Published: May 2014

AbstractA new and atom‐economic palladium‐catalyzed aminomethylamination of allenes with aminals by CN bond activation is described. This direct and operationally simple method provides a fundamentally novel approach for the synthesis of 1,3‐diamines. Mechanistic studies suggest that a unique cationic π‐allylpalladium complex containing an aminomethyl moiety is generated as a key intermediate through the carbopalladation of the allene with a cyclometalated palladium–alkyl species.
A Reagent for the One‐Step Preparation of Potassium Acyltrifluoroborates (KATs) from Aryl‐ and Heteroarylhalides
Authors: Erős Gábor , Kushida Yo , Bode Jeffrey W. 
Published: May 2014

AbstractPotassium acyltrifluoroborates (KATs) are fascinating functional groups whose further exploration is limited by poor synthetic access. Documented herein is the design and synthesis of a new reagent for their one‐step preparation from aryl‐ and heteroarylhalides. The reagent is a stable, soluble zwitterion prepared by S‐alkylation of a novel thioformamide trifluoroboronate. The KATs are prepared by adding one equivalent of nBuLi to a mixture of the aryl halide and the reagent at −78 °C. This protocol is suitable for the preparation of KATs containing pyridines, esters, nitro groups, and halides.
Rhodium(I)‐Catalyzed Cycloisomerization of Benzylallene‐Alkynes through CH Activation
Authors: Kawaguchi Yasuaki , Yasuda Shigeo , Kaneko Akira , Oura Yuki , Mukai Chisato 
Published: May 2014

AbstractThe efficient RhI‐catalyzed cycloisomerization of benzylallene‐alkynes produced the tricyclo[9.4.0.03,8]pentadecapentaene skeleton through a CH bond activation in good yields. A plausible reaction mechanism proceeds via oxidative addition of the acetylenic CH bond to RhI, an ene‐type cyclization to the vinylidenecarbene–RhI intermediate, and an electrophilic aromatic substitution with the vinylidenecarbene species. It was proposed based on deuteration and competition experiments.
A Tantalum Nitride Photoanode Modified with a Hole‐Storage Layer for Highly Stable Solar Water Splitting
Authors: Liu Guiji , Shi Jingying , Zhang Fuxiang , Chen Zheng , Han Jingfeng , Ding Chunmei , Chen Shanshan , Wang Zhiliang , Han Hongxian , Li Can 
Published: May 2014

AbstractPhotoelectrochemical (PEC) water splitting is an ideal approach for renewable solar fuel production. One of the major problems is that narrow bandgap semiconductors, such as tantalum nitride, though possessing desirable band alignment for water splitting, suffer from poor photostability for water oxidation. For the first time it is shown that the presence of a ferrihydrite layer permits sustainable water oxidation at the tantalum nitride photoanode for at least 6 h with a benchmark photocurrent over 5 mA cm−2, whereas the bare photoanode rapidly degrades within minutes. The remarkably enhanced photostability stems from the ferrihydrite, which acts as a hole‐storage layer. Furthermore, this work demonstrates that it can be a general strategy for protecting narrow bandgap semiconductors against photocorrosion in solar water splitting.
In Vivo Imaging of Mouse Tumors by a Lipidated Cathepsin S Substrate
Authors: Hu Hai‐Yu , Vats Divya , Vizovisek Matej , Kramer Lovro , Germanier Catherine , Wendt K. Ulrich , Rudin Markus , Turk Boris , Plettenburg Oliver , Schultz Carsten 
Published: May 2014

AbstractThe synthesis and evaluation of two cathepsin S‐specific probes is described. For long‐term retention of the probe at the target site and a high signal‐to‐noise ratio, we introduced a lipidation approach via the simple attachment of palmitoic acid to the reporter. After cathepsin S‐specific cleavage in cultured cells and in a grafted tumor mouse model, fluorescence increased owing to dequenching and we observed an intracellular accumulation of the fluorescence in the target tissue. The lipidated probe provided a prolonged and strongly fluorescent signal in tumors when compared to the very similar non‐lipidated probe, demonstrating that non‐invasive tumor identification is feasable. The homing principle by probe lipidation might also work for selective administration of cytotoxic compounds to specifically reduce tumor mass.
Selective Functionalization of P4 by Metal‐Mediated CP Bond Formation
Authors: Heinl Sebastian , Reisinger Sabine , Schwarzmaier Christoph , Bodensteiner Michael , Scheer Manfred 
Published: May 2014

AbstractA new and selective one‐step synthesis was developed for the first activation stage of white phosphorus by organic radicals. The reactions of NaCpR with P4 in the presence of CuX or FeBr3 leads to the clean formation of organic substituted P4 butterfly compounds CpR2P4 (CpR: CpBIG=C5(4‐nBuC6H4)5 (1 a), Cp′′′=C5H2tBu3 (1 b), Cp*=C5Me5 (1 c) und Cp4iPr=C5HiPr4 (1 d)). The reaction proceeds via the activation of P4 by CpR radicals mediated by transition metals. The newly formed organic derivatives of P4 have been comprehensively characterized by NMR spectroscopy and X‐ray crystallography.
Iterative Assembly of Two Separate Polyketide Chains by the Same Single‐Module Bacterial Polyketide Synthase in the Biosynthesis of HSAF
Authors: Li Yaoyao , Chen Haotong , Ding Yanjiao , Xie Yunxuan , Wang Haoxin , Cerny Ronald L. , Shen Yuemao , Du Liangcheng 
Published: May 2014

AbstractAntifungal HSAF (heat‐stable antifungal factor, dihydromaltophilin) is a polycyclic tetramate macrolactam from the biocontrol agent Lysobacter enzymogenes. Its biosynthetic gene cluster contains only a single‐module polyketide synthase–nonribosomal peptide synthetase (PKS‐NRPS), although two separate hexaketide chains are required to assemble the skeleton. To address the unusual biosynthetic mechanism, we expressed the biosynthetic genes in two “clean” strains of Streptomyces and showed the production of HSAF analogues and a polyene tetramate intermediate. We then expressed the PKS module in Escherichia coli and purified the enzyme. Upon incubation of the enzyme with acyl‐coenzyme A and reduced nicotinamide adenine dinucleotide phosphate (NADPH), a polyene was detected in the tryptic acyl carrier protein (ACP). Finally, we incubated the polyene–PKS with the NRPS module in the presence of ornithine and adenosine triphosphate (ATP), and we detected the same polyene tetramate as that in Streptomyces transformed with the PKS‐NRPS alone. Together, our results provide evidence for an unusual iterative biosynthetic mechanism for bacterial polyketide–peptide natural products.
A Highly Modular One‐Pot Multicomponent Approach to Functionalized Benzo[b]phosphole Derivatives
Authors: Wu Bin , Santra Mithun , Yoshikai Naohiko 
Published: May 2014

AbstractBenzo[b]phosphole derivatives have attracted significant attention for their unique optoelectronic properties with potential for application in materials science. Herein we report a modular approach to a benzo[b]phosphole derivative based on a one‐pot sequential coupling of an arylzinc reagent, an alkyne, dichlorophenylphosphine (or phosphorus trichloride and a Grignard reagent), and an oxidant (for example H2O2, S, or Se). The approach allows for the construction of a library of previously inaccessible, structurally diverse benzo[b]phosphole derivatives with unprecedented ease.
A comprehensive review of alkaline–surfactant–polymer (ASP) flooding
Authors: Sheng James J. 
Published: May 2014

ABSTRACTAlkaline–surfactant–polymer (ASP) flooding is a combination process in which alkali, surfactant, and polymer are injected in the same slug. Because of the synergy of these three components, ASP is the current worldwide focus of research and field trial in chemical enhanced oil recovery (EOR).This paper is to provide a comprehensive review of the ASP process. The reviewed topics include the following:ASP synergy and its EOR mechanismsScreening criteriaLaboratory workNumerical simulation workSummary of pilots and large‐scale applicationsProject economicsChemicals usedWater qualityMobility control requirementProblems associated with ASP flooding and possible solutionsIn addition to the comprehensive review, future developments are also discussed. Data and analyzed results presented in this review will provide the reader with the updated information about ASP and a guide to read relevant papers for those who are new to chemical EOR. The survey data also provide operators with some reference data for their project design and optimization. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Electrogenerated chemiluminescence of tris(2‐phenylpyridine)iridium(III) in water, acetonitrile and trifluorethanol
Authors: Robinson Wesley D. , Richter Mark M. 
Published: May 2014

AbstractThe spectroscopic, electrochemical and coreactant electrogenerated chemiluminescence (ECL) properties of Ir(ppy)3 (where ppy = 2‐phenylpyridine) have been obtained in aqueous buffered (KH2PO4), 50 : 50 (v/v) acetonitrile–aqueous buffered (MeCN–KH2PO4) and 30% trifluoroethanol (TFE) solutions. Tri‐n‐propylamine was used as the oxidative‐reductive ECL coreactant. The photoluminescence (PL) efficiency (ϕem) of Ir(ppy)3 in TFE (ϕem ≈ 0.029) was slightly higher than in 50 : 50 MeCN–KH2PO4 (ϕem ≈ 0.0021) and water (ϕem ≈ 0.00016) compared to a Ru(bpy)32+ standard solution in water (Φem ≈ 0.042). PL and ECL emission spectra were nearly identical in all three solvents, with dual emission maxima at 510 and 530 nm. The similarity between the ECL and PL spectra indicate that the same excited state is probably formed in both experiments. ECL efficiencies (ϕecl) in 30% TFE solution (ϕecl = 0.0098) were higher than aqueous solution (ϕecl = 0.00092) system yet lower than a 50% MeCN–KH2PO4 solution (ϕecl = 0.0091). Copyright © 2014 John Wiley & Sons, Ltd.