bluuebunny/crossref_metadata_2025_split huggingface dataset:
A possible explanation on the changes in the spatial structure of ENSO from CMIP3 to CMIP5
Authors: Yeh Sang‐Wook , Ham Yoo‐Geun , Kirtman Ben P. 
Published: December 2013

AbstractThis study examines changes in the structure of El Niño‐Southern Oscillation (ENSO) amplitude using the historical climate simulations of the World Climate Research Program Coupled Model Intercomparison Project (CMIP) phase‐3 and phase‐5 coupled general circulation models (CGCMs). The analysis focuses on the “so‐called” Bjerknes feedback. The Bjerknes feedback affects the sea surface temperature (SST) variability differently between the CMIP3 and CMIP5 models. In the CMIP5 models, the strength of the Bjerknes feedback is associated with the amplitude of ENSO, whereas the changes in the strength of Bjerknes feedback are not associated with changes in ENSO amplitude in CMIP3 CGCMs. The relationship between the Bjerknes feedback and the SST anomaly variance is suggested as a possible explanation for the eastward shift in the SST anomaly variance in CMIP5 relative to CMIP3.
Equatorial broad plasma depletions associated with the enhanced fountain effect
Authors: Lee Woo Kyoung , Kil Hyosub , Kwak Young‐Sil , Paxton Larry J. , Zhang Yongliang , Galkin Ivan , Batista Inez S. 
Published: December 2013

AbstractBroad plasma depletions (BPDs), plasma depletions whose longitudinal width is over several hundred kilometers, have been detected in the equatorial F region by low‐earth‐orbit satellites during both magnetically quiet and magnetically disturbed periods. A few hypotheses were suggested to explain the creation of BPDs, but the underlying mechanism of this phenomenon is still under debate. We investigate the origin of BPDs by analyzing the simultaneous in situ and optical observations of the ionosphere on 30 May 2003 (Kp = 8+), 24 April 2012 (Kp = 7−), and 31 October 2012 (Kp = 0+). BPDs on 30 May 2003 were detected by the Republic of China Satellite‐1 at an altitude of 600 km, and BPDs on the other days were detected by the Communication/Navigation Outage Forecasting System satellite near an altitude of 400 km. Our results show that the detection of BPDs is closely associated with background ionospheric morphology; BPDs are detected on the days when the equatorial ionization anomaly (EIA) is intense and the crests of the EIA have moved poleward. Measurements of upward plasma motion support the existence of ionospheric uplift at BPD locations. These observations and the detection of BPDs near the magnetic equator lead to the interpretation that the satellite detection of BPDs during those 3 days is likely related to the uplift of the F peak height above the satellite orbits.
A new estimate of the China temperature anomaly series and uncertainty assessment in 1900–2006
Authors: Wang Jinfeng , Xu Chengdong , Hu Maogui , Li Qinxiang , Yan Zhongwei , Zhao Ping , Jones Phil 
Published: December 2013

AbstractWhile global warming during the last century has been well recognized, the magnitude of the climate warming in regions such as China over the past 100 years still has some uncertainty due to limited observations during the early years. Several series of temperature anomalies for the 20thcentury in China have been independently developed by different groups. The uncertainty arises mainly from the sparse observations before 1950, where statistics are sensitive to the small and potentially biased sample. In this study, BSHADE‐MSN (Biased Sentinel Hospitals Areal Disease Estimation and Means of Stratified Nonhomogeneous Surface), a combination of two novel distinct statistical methods that are applicable with different sample situations to a spatial heterogeneous surface, is applied to estimate annual mean temperature anomalies for China. This method takes into account prior knowledge of geographical spatial autocorrelation and nonhomogeneity of target domains, remedies the biased sample, and maximizes an objective function for the best linear unbiased estimation (BLUE) of the regional mean quantity. For the period 1900–1999, the overall trend estimated by BSHADE‐MSN is 0.80°C with a 95% confidential interval between 0.41°C and 1.18°C. This is significantly lower than that calculated by Climate Anomaly Method (CAM) and Block Kriging. The new temperature anomaly series for China exhibits slightly warmer conditions for the period before 1950 than existing studies. All the methods applied so far agree well with each other for the period after 1950, when there are sufficient stations across the country for the estimation of temperature anomaly series. Cross validation shows that the new regional mean temperature anomaly series has smaller estimation error variance and higher accuracy than those based on the other methods assessed in this study.
Comparison of magnetic perturbation data from LEO satellite constellations: Statistics of DMSP and AMPERE
Authors: Knipp D. J. , Matsuo T. , Kilcommons L. , Richmond A. , Anderson B. , Korth H. , Redmon R. , Mero B. , Parrish N. 
Published: December 2013

AbstractDuring the past decade engineering‐grade magnetic field measurements from the low Earth orbiting (LEO) Iridium constellation of communication satellites have been available to the geospace science community as a tool to map field‐aligned currents. The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) applied to Iridium measurements markedly improved the temporal and spatial resolution of these data. We developed new methods to compare data from the latest improvement to AMPERE with those from a constellation of four LEO Defense Meteorological Satellite Program (DMSP) spacecraft that carry high‐resolution magnetometers. To perform the comparisons, we transformed all data to a common coordinate frame and altitude (110 km) and developed a means of computing spacecraft magnetic conjunctions. These conjunctions yield discrepancies in the magnetic field perturbations measured at each proximate spacecraft. During the geomagnetic disturbance of 29–30 May 2010, the vector differences in the horizontal perturbations at closest approach (typically a few tens of kilometers) had mean, median, and standard deviation values of 132 nT, 112 nT, and 90 nT, respectively. The DMSP spacecraft tend to report larger perturbations in the northern polar cap and cusp regions, especially during active intervals. We attribute some of the differences to limitations of spacecraft‐attitude knowledge that propagate into AMPERE data. Overall, for the magnetic storm, we provide clear evidence that AMPERE data can provide high‐resolution auroral zone data in good agreement with DMSP data for use in data assimilation algorithms. Such dual‐use commercial data can provide important global augmentation to the nation's space weather monitoring capabilities.
Copper(I)/N‐Heterocyclic Carbene (NHC)‐Catalyzed Addition of Terminal Alkynes to Trifluoromethyl Ketones for Use in Continuous Reactors
Authors: Correia Camille A. , McQuade D. Tyler , Seeberger Peter H. 
Published: December 2013

AbstractA copper(I)/N‐heterocyclic carbene complex‐catalyzed addition of terminal alkynes to trifluoromethyl ketones at low loading is described. The developed process functions well using a range of terminal alkynes but functions best when an aryl trifluoromethyl ketone is used. This substrate scope is well‐suited for the production of active pharmaceutical ingredients (APIs) such as efavirenz. In this vein, we demonstrate that the described method can be translated into a flow process laying the framework for a completely continuous synthesis of efavirenz in the future.magnified image
Orthopedics management of acromicric dysplasia: Follow up of nine patients
Authors: Klein Céline , Le Goff Carine , Topouchian Vicken , Odent Sylvie , Violas Philippe , Glorion Christophe , Cormier‐Daire Valérie 
Published: December 2013

AbstractAcromicric dysplasia (AD) is an autosomal dominant disorder characterized by short stature, short extremities, stiff joint and skeleton features including brachymetacarpia, cone‐shaped epiphyses, internal notch of the femoral head, and delayed bone age. Recently, we identified fibrillin 1 (FBN1) as the disease gene of AD. The aim of our study was to further describe the long‐term follow up of AD patients with an emphasis on orthopedic management. Nine patients with FBN1 mutations were included in the study ranging in age from 5.5 to 64 years. For all, detailed clinical and radiological data were available. Results: Birth parameters were always normal and patients progressively developed short stature <−3 SD. Carpal tunnel syndrome was observed in four patients. We found discrepancy between the carpal bone age and the radius and ulna epiphysis bone ages, a variable severity of hip dysplasia with acetabular dysplasia, epiphyseal and metaphyseal femoral dysplasia resembling Legg–Perthes–Calvé disease and variable pelvic anteversion and hyperlordosis. Orthopedic surgery was required in two patients for hip dysplasia, in one for limb lengthening and in three for carpal tunnel syndrome. Our observations expand the AD phenotype and emphasize the importance of regular orthopedic survey. © 2013 Wiley Periodicals, Inc.
Synthesis, Characterization, and Sensing Behavior of an N‐heteropentacene
Authors: Li Gang , Gao Junkuo , Zhang Qichun 
Published: December 2013

AbstractAn N‐heteropentacene, 1,2,5,6‐tetra(5‐hexylthiophene‐2‐yl)‐hexaazapentacene (4HP), was synthesized through one‐step cyclocondensation reaction. The binding behavior of 4HP toward various cations (Ca2+, Cd2+, Co2+, Cr2+, Cu2+ Fe3+, Hg2+, K+, Li+, Mg2+, Mn2+, Na+, Ni2+, Zn2+, and Pb2) was investigated by UV/vis and fluorescence spectroscopy. 4HP demonstrated a selective and sensitive response towards Cu2+ ion, and the detection limit reached 1.2 μM in N,N‐dimethylformamide solution.
Photo‐Cross‐Linking Probes for Trapping G‐Quadruplex DNA
Authors: Verga Daniela , Hamon Florian , Poyer Florent , Bombard Sophie , Teulade‐Fichou Marie‐Paule 
Published: December 2013

AbstractWe have developed a straightforward synthetic pathway to a set of six photoactivatable G‐quadruplex ligands with a validated G4‐binding motif (the bisquinolinium pyridodicarboxamide PDC‐360A) tethered through various spacers to two different photo‐cross‐linking groups: benzophenone and an aryl azide. The high quadruplex‐versus‐duplex selectivity of the PDC core was retained in the new derivatives and resulted in selective alkylation of two well‐known G‐quadruplexes (human telomeric G4 and oncogene promoter c‐myc G4) under conditions of harsh competition. The presence of two structurally different photoactivatable functions allowed the selective alkylation of G‐quadruplex structures at specific nucleobases and irreversible G4 binding. The topology and sequence of the quadruplex matrix appear to influence strongly the alkylation profile, which differs for the telomeric and c‐myc quadruplexes. The new compounds are photoactive in cells and thus provide new tools for studying G4 biology.
Formylborane Formation with Frustrated Lewis Pair Templates
Authors: Sajid Muhammad , Kehr Gerald , Daniliuc Constantin G. , Erker Gerhard 
Published: December 2013

AbstractBoranes R2BH react with carbon monoxide by forming the respective borane carbonyl compounds R2BH(CO). The formation of (C6F5)2BH(CO) derived from the Piers borane, HB(C6F5)2, is a typical example. Subsequent CO‐hydroboration does not take place, since the formation of the formylborane is usually endothermic. However, an “η2‐formylborane” was formed by CO‐hydroboration with the Piers borane at vicinal phosphane/borane frustrated Lewis pair (FLP) templates. Subsequent treatment with pyridine liberated the intact formylborane from the FLP framework, and (pyridine)(C6F5)2BCHO was then isolated as a stable compound. This product underwent typical reactions of carbonyl compounds, such as Wittig olefination.
Dehydrierende Meyer‐Schuster‐Umlagerung: Gold‐katalysierte Synthese von Alkinen
Authors: Yu Yang , Yang Weibo , Pflästerer Daniel , Hashmi A. Stephen K. 
Published: December 2013

AbstractLeicht zugängliche Propargylester werden durch eine oxidative Gold‐katalysierte Reaktion in die invertierten Alkinylketone überführt. Der Gagosz‐Katalysator in Kombination mit PhI(OAc)2 erweist sich als das beste System für diese Umwandlung, und 18 Beispiele mit Ausbeuten bis zu 80 % werden beschrieben. Die Ergebnisse lassen darauf schließen, dass die Dreifachbindung im Produkt durch Eliminierung aus einer Vinylgold‐Zwischenstufe entsteht. Formal ist diese neue Reaktion eine dehydrierende Meyer‐Schuster‐Umlagerung.
Oxidative Addition von 2‐Halogenazolen – direkte Synthese von Palladium(II)‐Komplexen mit protischen NH,NH‐funktionalisierten NHC‐Liganden
Authors: Das Rajorshi , Daniliuc Constantin G. , Hahn F. Ekkehardt 
Published: December 2013

AbstractDie Chemie der N‐heterocyclischen Carbene (NHCs) wird von N,N′‐dialkylierten oder ‐diarylierten Derivaten dominiert. Derartige Carbenliganden werden normalerweise durch C2‐Deprotonierung von Azoliumkationen oder durch reduktive Entschwefelung von Azol‐2‐thionen erhalten. Wir beschreiben hier eine einfache Prozedur für die Synthese von Komplexen mit NH,NH‐NHC‐Liganden, die durch oxidative Addition von 2‐Halogenazolen an Komplexe mit nullwertigen Übergangsmetallen erhalten werden.
Metal–Organic Organopolymeric Hybrid Framework by Reversible [2+2] Cycloaddition Reaction
Authors: Park In‐Hyeok , Chanthapally Anjana , Zhang Zhenjie , Lee Shim Sung , Zaworotko Michael J. , Vittal Jagadese J. 
Published: December 2013

AbstractOrganic polymers are usually amorphous or possess very low crystallinity. The metal complexes of organic polymeric ligands are also difficult to crystallize by traditional methods because of their poor solubilities and their 3D structures can not be determined by single‐crystal X‐ray crystallography owing to a lack of single crystals. Herein, we report the crystal structure of a 1D ZnII coordination polymer fused with an organic polymer ligand made in situ by a [2+2] cycloaddition reaction of a six‐fold interpenetrated metal–organic framework. It is also shown that this organic polymer ligand can be depolymerized in a single‐crystal‐to‐single‐crystal (SCSC) fashion by heating. This strategy could potentially be extended to make a range of monocrystalline metal organopolymeric complexes and metal–organic organopolymeric hybrid materials. Such monocrystalline metal complexes of organic polymers have hitherto been inaccessible for materials researchers.
Overcoming the Unexpected Functional Inversion of a PqsR Antagonist in Pseudomonas aeruginosa: An In Vivo Potent Antivirulence Agent Targeting pqs Quorum Sensing
Authors: Lu Cenbin , Maurer Christine K. , Kirsch Benjamin , Steinbach Anke , Hartmann Rolf W. 
Published: December 2013

AbstractThe virulence regulator PqsR of Pseudomonas aeruginosa is considered as an attractive target for attenuating the bacterial pathogenicity without eliciting resistance. However, despite efforts and desires, no promising PqsR antagonist has been discovered thus far. Now, a surprising functionality change of a highly affine PqsR antagonist in P. aeruginosa is revealed, which is mediated by a bacterial signal molecule synthase and responsible for low cellular potency. Blockade of the susceptible position led to the discovery of the first antivirulence compound that is potent in vivo and targets PqsR, thus providing a proof of concept for this novel antivirulence therapy.
Dehydrogenative Meyer–Schuster‐Like Rearrangement: A Gold‐Catalyzed Reaction Generating an Alkyne
Authors: Yu Yang , Yang Weibo , Pflästerer Daniel , Hashmi A. Stephen K. 
Published: December 2013

AbstractEasily accessible propargylic esters are converted to the inverted alkynyl ketones in an oxidative gold‐catalyzed reaction. Gagosz’s catalyst in combination with PhI(OAc)2 is the best system for this conversion and 18 examples with yields up to 80 % are reported. The results indicate that the triple bond in the product is formed by elimination from a vinylgold intermediate. In a formal sense the new conversion overall is a dehydrogenative Meyer–Schuster rearrangement.
Total Synthesis of (−)‐Ophiodilactone A and (−)‐Ophiodilactone B
Authors: Matsubara Takaaki , Takahashi Keisuke , Ishihara Jun , Hatakeyama Susumi 
Published: December 2013

AbstractThe first asymmetric total synthesis of (−)‐ophiodilactone A and (−)‐ophiodilactone B, isolated from the ophiuroid (Ophiocoma scolopendrina), is reported. The key features of the synthesis include the highly stereocontrolled construction of the structurally congested γ‐lactone/δ‐lactone skeleton through an asymmetric epoxidation, diastereoselective iodolactonization, and intramolecular epoxide‐opening with a carboxylic acid, and biomimetic radical cyclization of ophiodilactone A to ophiodilactone B.
The Strongest Brønsted Acid: Protonation of Alkanes by H(CHB11F11) at Room Temperature
Authors: Nava Matthew , Stoyanova Irina V. , Cummings Steven , Stoyanov Evgenii S. , Reed Christopher A. 
Published: December 2013

AbstractWhat is the strongest acid? Can a simple Brønsted acid be prepared that can protonate an alkane at room temperature? Can that acid be free of the complicating effects of added Lewis acids that are typical of common, difficult‐to‐handle superacid mixtures? The carborane superacid H(CHB11F11) is that acid. It is an extremely moisture‐sensitive solid, prepared by treatment of anhydrous HCl with [Et3SiHSiEt3][CHB11F11]. It adds H2O to form [H3O][CHB11F11] and benzene to form the benzenium ion salt [C6H7][CHB11F11]. It reacts with butane to form a crystalline tBu+ salt and with n‐hexane to form an isolable hexyl carbocation salt. Carbocations, which are thus no longer transient intermediates, react with NaH either by hydride addition to re‐form an alkane or by deprotonation to form an alkene and H2. By protonating alkanes at room temperature, the reactivity of H(CHB11F11) opens up new opportunities for the easier study of acid‐catalyzed hydrocarbon reforming.
Photoactivity of Poly(lactic acid) nanocomposites modulated by TiO2 nanofillers
Authors: Li Yonghui , Chen Caihong , Li Jun , Susan Sun Xiuzhi 
Published: December 2013

ABSTRACTPhotoactivity of poly(lactic acid) (PLA) nanocomposites is of great interest for rational design of products for either short‐term/single‐use or long‐term/durable applications. We prepared PLA/TiO2 nanocomposite films through a solution mixing/film casting method. Results showed that photodegradability/photostability of PLA could be well modulated by selecting appropriate TiO2 nanofillers. TiO2 nanoparticles and nanowires were characterized using X‐ray diffraction, UV–Vis–NIR spectrophotometer, and scanning electron microscopy. Changes in color, weight, structure, thermal stability, and phase transitions of PLA and nanocomposite films before and after UV irradiation were evaluated to study photoactivity characteristics. Pure PLA exhibited moderate photodegradability, but the photodegradability and photostability of PLA nanocomposites (PNA) were significantly enhanced by NanoActive (NA) TiO2 nanoparticles and A type TiO2 nanowires, respectively. Pure PLA had a weight loss of 27% after 38 days of UV irradiation. The weight loss of photodegradable (PD) PNA (PNA = PLA with 1% NA TiO2) reached 38%, whereas that of photostable (PS) nanocomposites (P3AW) (P3AW = PLA with 3% A type TiO2 nanowire) was only 5%. PD PLA exhibited characteristic peaks of carboxylic acid OH stretching and CC double bond after UV irradiation in Fourier‐transform infrared spectra, whereas spectra of PS PLA remained almost the same. Thermal decomposition temperatures, glass transition temperatures, and melting temperatures of PD PLAs decreased dramatically after UV irradiation, but no obvious changes were observed for those of PS PLAs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40241.
Effects of inorganic fillers on the flame‐retardant and mechanical properties of rigid polyurethane foams
Authors: Cheng Jia‐Ji , Shi Bo‐Bo , Zhou Fu‐Bao , Chen Xiao‐Yu 
Published: December 2013

AbstractRigid polyurethane foam (RPUF) composites filled with expandable graphite (EG), hollow glass microspheres (HGM), and glass fibers (GF) have been synthesized and characterized by limiting oxygen index, radiation ignition, compressing and torsion testing, and scanning electron microscopy. The results indicate HGM and GF benefit to the mechanical properties, while EG is good for flame retardancy. Proper ingredient of additive can lead to good flame retardancy and mechanical properties of the RPUF. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40253.
Switchable Substrates for Analyzing and Engineering Cellular Functions
Authors: Nakanishi Jun 
Published: December 2013

AbstractCellular activity is highly dependent on the extracellular environment, which is composed of surrounding cells and extracellular matrices. This focus review summarizes recent advances in chemically and physically engineered switchable substrates designed to control such cellular microenvironments by application of an external stimulus. Special attention is given to their molecular design, switching strategies, and representative examples for bioanalytical and biomedical applications.
Simultaneous determination of some dihydroxybenzenesulphonic acid derivatives and their degradation product and main impurity (hydroquinone) by ion‐pair liquid chromatography
Authors: Tolba M. M. 
Published: December 2013

ABSTRACTA simple and sensitive high‐performance liquid chromatography method was developed and validated for the determination of calcium dobesilate (DOB) or ethamsylate (ETM) in the presence of their degradation product, hydroquinone (HQ). The analyses were carried out on Promosil C18 column (4.6 mm × 250 mm, 5 µm particle size) using an ion‐pair mobile phase consisting of methanol–1.5 mm tetra‐butyl ammonium bromide in 0.06 m phosphate buffer (25 : 75, v/v) at pH 6.0 with fluorescence detection at 286/333 nm. Pindolol was used as an internal standard. The proposed method was found to be rectilinear over the concentration ranges of 0.05–0.5 µg/mL for DOB, 0.1–0.8 µg/mL for ETM and 0.005–0.1 µg/mL for HQ. The method was applied for the determination of the studied drugs in different dosage forms and biological fluids. The results of the proposed method were statistically compared with those obtained by the comparison methods revealing no significance differences in the performance of the methods regarding accuracy and precision. Moreover, applying a time‐programmed fluorescence technique was valuable for the detection of trace amounts of HQ as an impurity and allowed purity testing of ETM or DOB within the BP pharmacopeial limit (0.1%). Copyright © 2013 John Wiley & Sons, Ltd.
Fallenbewegungen fleischfressender Pflanzen
Authors: Poppinga Simon , Metzger Amélie , Speck Olga , Masselter Tom , Speck Thomas 
Published: December 2013

AbstractLangsame Pflanzenbewegungen laufen vornehmlich mit hydraulischen “Motoren” ab, d. h. die auftretenden Verformungen werden durch eine Verschiebung von Wasser zwischen Zellen und Geweben hervorgerufen. Vor allem bei großen und schnellen Strukturen (zum Beispiel den Schnappfallen der carnivoren Venusfliegenfalle) treten elastische Instabilitäten auf und beschleunigen den Bewegungsvorgang deutlich. Die bei den vorgestellten carnivoren Pflanzen zur Anwendung kommenden mechanischen “Tricks” lassen sich in abstrahierter Form mittels einfacher physikalischer Handmodelle veranschaulichen und tragen zum Verständnis der involvierten Prozesse bei.