bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonmigrating tidal signature in the distributions of equatorial plasma bubbles and prereversal enhancement
Authors: Kil Hyosub , Kwak Young‐Sil , Lee Woo Kyoung , Krall Jonathan , Huba Joseph D. , Oh Seung‐Jun 
Published: March 2015

AbstractSome wave‐like features in the longitudinal distribution of equatorial plasma bubbles understood in association with diurnal eastward propagating zonal wave number 3 nonmigrating tide (DE3) in the dayside. However, whether or not the wave features are the daytime DE3 signature has not yet been rigorously investigated. This study investigates (1) the existence of the DE3 signature in the longitudinal distribution of bubbles by analyzing the first Republic of China (ROCSAT‐1) satellite data acquired in 2000–2002 and (2) the role of daytime DE3 in the creation of bubbles by examining the linear growth rate of the generalized Rayleigh‐Taylor (R‐T) instability. The linear growth rate is derived from the “Sami2 is Another Model of the Ionosphere” model simulation results. In the longitudinal distribution of bubbles derived from ROCSAT‐1 observations, the wave number 4 component, the representative characteristic of DE3, is a weak feature. In addition, the amplitude and phase of the wave number 4 component do not show a consistent behavior in comparison with those of DE3. Our numerical calculation results show that the linear growth rate of the R‐T instability is not sensitive to the variation of the daytime vertical plasma drift. These results indicate that the DE3 signature in the occurrence rate of bubbles is not obvious and the effect of daytime DE3 on the creation of bubbles is negligible.
Six hundred thirty‐eight years of summer temperature variability over the Bhutanese Himalaya
Authors: Krusic P. J. , Cook E. R. , Dukpa D. , Putnam A. E. , Rupper S. , Schaefer J. 
Published: March 2015

AbstractHigh‐resolution tree ring reconstructions from the Himalaya provide essential context for assessing impacts of future climate change on regional water reserves and downstream agriculture. Here we evaluate a small network of tree ring chronologies from Bhutan to produce a 638 year summer temperature reconstruction, from 1376–2013 (Common Era) C.E. Relative to the 1950–2013 C.E. average summer temperature three prominent cold periods stand out, two in the midfifteenth century, and one in the late seventeenth century. The warmest period began in the first decade of the 21st century coinciding with the timing of general glacier recession in the eastern Himalaya that continues to the present. The Bhutan temperature reconstruction exhibits a significant correlation to known volcanic eruptions (p = 97%) and anomalously cold periods appear to align with solar irradiance minima in the fifteenth, late seventeenth, and early nineteenth centuries, implying a link between solar variability and decadal‐scale temperature variability.
Magnetosheath plasma stability and ULF wave occurrence as a function of location in the magnetosheath and upstream bow shock parameters
Authors: Soucek Jan , Escoubet C. Philippe , Grison Benjamin 
Published: March 2015

AbstractWe present the results of a statistical study of the distribution of mirror and Alfvén‐ion cyclotron (AIC) waves in the magnetosheath together with plasma parameters important for the stability of ULF waves, specifically ion temperature anisotropy and ion beta. Magnetosheath crossings registered by Cluster spacecraft over the course of 2 years served as a basis for the statistics. For each observation we used bow shock, magnetopause, and magnetosheath flow models to identify the relative position of the spacecraft with respect to magnetosheath boundaries and local properties of the upstream shock crossing. A strong dependence of both plasma parameters and mirror/AIC wave occurrence on upstream ΘBn and MA is identified. We analyzed a joint dependence of the same parameters on ΘBn and fractional distance between shock and magnetopause, zenith angle, and length of the flow line. Finally, the occurrence of mirror and AIC modes was compared against the respective instability thresholds. We noted that AIC waves occurred nearly exclusively under mirror stable conditions. This is interpreted in terms of different characters of nonlinear saturation of the two modes.
Solar cycle dependence of substorm occurrence and duration: Implications for onset
Authors: Chu Xiangning , McPherron Robert L. , Hsu Tung‐Shin , Angelopoulos Vassilis 
Published: March 2015

AbstractMagnetospheric substorms represent a major energy release process in Earth's magnetosphere. Their duration and intensity are coupled to solar wind input, but the precise way the solar wind energy is stored and then released is a matter of considerable debate. Part of the observational difficulty has been the gaps in the auroral electrojet index traditionally used to study substorm properties. In this study, we created a midlatitude positive bay (MPB) index to measure the strength of the substorm current wedge. Because this index is based on midlatitude magnetometer data that are available continuously over several decades, we can assemble a database of substorm onsets lasting 31 years (1982–2012). We confirmed that the MPB onsets have a good agreement (±2 min) with auroral onsets as determined by optical means on board the IMAGE mission and that the MPB signature of substorms is robust and independent of the stations' position relative to ionospheric currents. Using the MPB onset, expansion, and recovery as a proxy of the respective substorm quantities, we found that the solar cycle variation of substorm occurrence depends on solar wind conditions and has a most probable value of 80 min. In contrast, the durations of substorm expansion and recovery phases do not change with the solar cycle. This suggests that the frequency of energy unloading in the magnetosphere is controlled by solar wind conditions through dayside reconnection, but the unloading process related to flux pileup in the near‐Earth region is controlled by the magnetosphere and independent of external driving.
Monofluoromethylation of Tetrahydroisoquinolines by Visible‐light Induced Direct C(sp3)H Bond Activation
Authors: Li Weipeng , Zhu Yunhuang , Duan Yingqian , Zhang Muliang , Zhu Chengjian 
Published: March 2015

AbstractA visible‐light photoredox‐catalyzed reaction of tetrahydroisoquinolines with β‐fluorinated gem‐diols results in the formation of C1‐monofluoromethylated tetrahydroisoquinolines via C(sp3)H bond activation. This protocol provides a new method to introduce a CF group with stable, easily‐prepared monofluorinated gem‐diol as CF source. A mechanistic investigation is presented based on control experiments.magnified image
Staphylococcus aureus impairs the airway epithelial barrier in vitro
Authors: Malik Zacki , Roscioli Eugene , Murphy Jae , Ou Judy , Bassiouni Ahmed , Wormald Peter‐John , Vreugde Sarah 
Published: March 2015

BackgroundChronic rhinosinusitis (CRS) is a cluster of disorders that result in sinonasal mucosal inflammation. Staphylococcus aureus (S. aureus) is associated with severe and recalcitrant CRS. The purpose of our study was to investigate the effect of S. aureus on respiratory epithelial barrier structure and function.MethodsConditioned media from S. aureus reference strains (American Type Culture Collection [ATCC] 13565, 14458, and 25923) was applied to air‐liquid interface (ALI) cultures of primary human nasal epithelial cells (HNECs) and transepithelial electrical resistance (TEER) was measured to assess cell‐to‐cell integrity. Electron microscopy was used to gauge the ciliated area and tight junctions (TJs). Additionally, the expression of the TJ protein zona occludens‐1 (ZO‐1) was examined via immunofluorescence. Statistical analysis was performed using analysis of variance (ANOVA) with pairwise Bonferroni‐adjusted t tests.ResultsSecreted products applied to ALI cultures from S. aureus strain 13565 caused a concentration‐dependent decline in electrical impedance compared to controls and reference strains 14458 and 25923 (p < 0.001). Electron microscopy showed a distinct separation between adjacent cells apically, in the region of TJs. The ciliated area was not affected; however, ZO‐1 expression became discontinuous in HNECs exposed to the 13565 strain's conditioned media.ConclusionConditioned media of the S. aureus strain 13565 damages the airway epithelium by disrupting the TJs between primary HNECs grown at an ALI. These findings suggest that strain‐specific S. aureus–secreted product(s) compromise epithelial barrier function, which may constitute 1 of the roles played by S. aureus in the pathophysiology of recalcitrant CRS. Further research is required to uncover the relevant molecular mechanisms.
Chirale Sulfoxidliganden für die asymmetrische Katalyse
Authors: Trost Barry M. , Rao Meera 
Published: March 2015

AbstractStickstoff‐, Sauerstoff‐ und Phosphorliganden mit chiralen Grundgerüsten sind die historischen Arbeitspferde für asymmetrische übergangsmetallkatalysierte Reaktionen. Dagegen wurden am Schwefelatom chirale Sulfoxide überwiegend als chirale Auxiliare für diastereoselektive Reaktionen verwendet. Obwohl diese Verbindungen gegenüber den üblichen Ligandengerüsten mehrere deutliche Vorteile bieten, z. B. die Nähe der chiralen Information zum Metallzentrum und die Fähigkeit, zwischen S‐ und O‐Koordinierung zu wechseln, entwickelten sie sich erst in jüngster Zeit zu einer vielseitigen Klasse chiraler Liganden. In diesem Aufsatz wird die Geschichte der Entwicklung chiraler Sulfoxidliganden für die asymmetrische Katalyse eingehend besprochen. Darüber hinaus geben wir kurze Beschreibungen der Metall‐Sulfoxid‐Bindung und der Synthesestrategien für enantiomerenreine Sulfoxide. Abschließend werden Einblicke in die künftige Entwicklung dieser nur wenig genutzten Ligandenklasse gegeben.
Self‐Discriminating Termination of Chiral Supramolecular Polymerization: Tuning the Length of Nanofibers
Authors: Kumar Jatish , Tsumatori Hiroyuki , Yuasa Junpei , Kawai Tsuyoshi , Nakashima Takuya 
Published: March 2015

AbstractDirecting the supramolecular polymerization towards a preferred type of organization is extremely important in the design of functional soft materials. Proposed herein is a simple methodology to tune the length and optical chirality of supramolecular polymers formed from a chiral bichromophoric binaphthalene by the control of enantiomeric excess (ee). The enantiopure compound gave thin fibers longer than a few microns, while the racemic mixture favored the formation of nanoparticles. The thermodynamic study unveils that the heterochiral assembly gets preference over the homochiral assembly. The stronger heterochiral binding over homochiral one terminated the elongation of fibrous assembly, thus leading to a control over the length of fibers in the nonracemic mixtures. The supramolecular polymerization driven by π–π interactions highlights the effect of the geometry of a twisted π‐core on this self‐sorting assembly.
Z‐Selective Cross Metathesis with Ruthenium Catalysts: Synthetic Applications and Mechanistic Implications
Authors: Herbert Myles B. , Grubbs Robert H. 
Published: March 2015

AbstractOlefin cross metathesis is a particularly powerful transformation that has been exploited extensively for the formation of complex products. Until recently, however, constructing Z‐olefins using this methodology was not possible. With the discovery and development of three families of ruthenium‐based Z‐selective catalysts, the formation of Z‐olefins using metathesis is now not only possible but becoming increasingly prevalent in the literature. In particular, ruthenium complexes containing cyclometalated NHC architectures developed in our group have been shown to catalyze various cross metathesis reactions with high activity and, in most cases, near perfect selectivity for the Z‐isomer. The types of cross metathesis reactions investigated thus far are presented here and explored in depth.
A Pyrene‐Fused N‐Heteroacene with Eleven Rectilinearly Annulated Aromatic Rings
Authors: Kohl Bernd , Rominger Frank , Mastalerz Michael 
Published: March 2015

AbstractA highly soluble pyrene‐fused undecacene is realized by end‐capping the rectilinear aromatic π‐plane with triptycenylene units. Besides the good solubility, the compound shows a high tendency to crystallize. Two polymorphs from dichlorobenzene and chloroform are described. In the polymorph from chloroform, half of the molecules are strongly bent out of the π‐plane by 26.4°.
Reversible 1,1‐Hydroboration: Boryl Insertion into a CN Bond and Competitive Elimination of HBR2 or RH
Authors: Yang Deng‐Tao , Mellerup Soren K. , Wang Xiang , Lu Jia‐Sheng , Wang Suning 
Published: March 2015

AbstractBoranes with the general formula of HBR2 have been found to undergo a facile 1,1‐hydroboration reaction with pyrido[1,2‐a]isoindole (A), resulting in insertion of a BR2 unit into a CN bond and the formation of a variety of BN heterocycles. Investigation on the thermal reactivity of the BN heterocycles revealed that these molecules have two distinct and competitive thermal elimination pathways: HBR2 elimination (or retro‐hydroboration) versus RH elimination, depending on the R group on the B atom and the chelate backbone. Mechanistic aspects of these highly unusual reactions have been established from both experimental and computational evidence. Adduct formation between HBR2 and A was found to be the key intermediate in 1,1‐hydroboration of A.
Beyond Acid Strength in Zeolites: Soft Framework Counteranions for Stabilization of Carbocations on Zeolites and Its Implication in Organic Synthesis
Authors: Cabrero‐Antonino Jose R. , Leyva‐Pérez Antonio , Corma Avelino 
Published: March 2015

AbstractThe generation of a carbocation with an acid depends not only on the acid strength but also on the ability of the counteranion to stabilize the positive charge left behind. Here we report that despite their relatively weak acidity, zeolites are able to generate and stabilize medium‐size (molecular weight ≈300 Da) delocalized carbocations on their surface under mild reaction conditions, as it can be done by strong Brønsted or Lewis acids in solution. The zeolite thus acts as a soft macroanion, prolonging the lifetime of the carbocation sufficiently to perform multifunctionalization reactions with amides, thioamides, and phenols, with high yield and selectivity. Biological studies show that some of the products obtained here present significant inhibition activity against colon cancer cells, illustrating the new possibilities of zeolites to prepare complex organic molecules.
Identifying key habitats for the conservation of Chilean dolphins in the fjords of southern Chile
Authors: Viddi Francisco A. , Harcourt Robert G. , Hucke‐Gaete Rodrigo 
Published: March 2015

Abstract

In the face of environmental degradation, animals with limited plasticity are likely to be the most vulnerable.
Habitat selection by the threatened, endemic Chilean dolphin (Cephalorhynchus eutropia) was investigated in the northern Patagonian fjords, an area of extraordinary biological productivity.
Generalized additive models were undertaken to assess the ecological determinants of Chilean dolphin spatial distribution and habitat selection. Data were collected from dedicated fine‐scale marine surveys conducted during the austral summer of 2007, 2008 and 2009
Modelling techniques provide strong support for Chilean dolphins aggregating in distinct hotspots, preferring shallow water, near rivers and in areas where the influence of tidal regime is greater.
The preference for coastal shallow waters and river influenced habitats by Chilean dolphins puts them in direct conflict with a growing aquaculture industry and hydropower projects. The models predict areas of high densities of Chilean dolphins and excluding these areas from new developments would provide clear protection to the habitat most important to this poorly known endemic Chilean species.
Copyright © 2015 John Wiley & Sons, Ltd.
Composite State Feedback of the Finite Frequency H∞ Control for Discrete‐Time Singularly Perturbed Systems
Authors: Xu Jing , Cai Chenxiao , Zou Yun 
Published: March 2015

AbstractThis paper mainly is concerned with the finite frequency H∞ control for the discrete‐time singularly perturbed systems. A state feedback controller is designed to stabilize the whole system and to satisfy the desired design specifications. The generalized Kalman–Yakubovich–Popov (GKYP) lemma is used to convert the related frequency domain inequalities in finite frequency ranges to feasible linear matrix inequalities. Based on the Lyapunov stability method, stable conditions are obtained for discrete‐time singularly perturbed systems. A bounded real lemma then is derived, which characterizes the H∞ norm performance in specific frequency ranges. Furthermore, the approach for the design of a composite state feedback controller is put forward combined with the unique frequency characteristics of singularly perturbed systems. Detailed analysis of the performance achieved by the piecewise composite controller is provided when it is applied to the original system, and the effectiveness and merits of the proposed controller are illustrated with a numerical result.
SENP1 regulates cell migration and invasion in neuroblastoma
Authors: Xiang‐ming Yan , Zhi‐qiang Xu , Ting Zhang , Jian Wang , Jian Pan , Li‐qun Yuan , Ming‐cui Fu , Hong‐liang Xia , Xu Cao , Yun Zhou 
Published: March 2015

AbstractNeuroblastoma (NB) is an embryonic solid tumor derived from precursor cells of the sympathetic nervous system, and accounts for 11% of childhood cancers and around 15% of cancer deaths in children. SUMOylation and deSUMOylation are dynamic mechanisms regulating a spectrum of protein activities. The SUMO proteases (SENP) remove SUMO conjugate from proteins, and their expression is deregulated in diverse cancers. However, nothing is known about the role of SENPs in NBL. In the present study, we found that SENP1 expression was significantly high in metastatic NB tissues compared with primary NB tissues. Overexpression of SENP1 promoted NB cells migration and invasion. Inhibition of SENP1 could significantly suppress NB cell migration and invasion. Moreover, we found that SENP1 could regulate the expression of CDH1, MMP9, and MMP2. In summary, the data presented here indicate a significant role of SENP1 in the regulation of cell migration and invasion in NB and suppress SENP1 expression as promising candidates for novel treatment strategies of NB.
Teaching bioprocess engineering to undergraduates: Multidisciplinary hands‐on training in a one‐week practical course
Authors: Henkel Marius , Zwick Michaela , Beuker Janina , Willenbacher Judit , Baumann Sandra , Oswald Florian , Neumann Anke , Siemann‐Herzberg Martin , Syldatk Christoph , Hausmann Rudolf 
Published: March 2015

AbstractBioprocess engineering is a highly interdisciplinary field of study which is strongly benefited by practical courses where students can actively experience the interconnection between biology, engineering, and physical sciences. This work describes a lab course developed for 2nd year undergraduate students of bioprocess engineering and related disciplines, where students are challenged with a real‐life bioprocess‐engineering application, the production of recombinant protein in a fed‐batch process. The lab course was designed to introduce students to the subject of operating and supervising an experiment in a bioreactor, along with the analysis of collected data and a final critical evaluation of the experiment. To provide visual feedback of the experimental outcome, the organism used during class was Escherichia coli which carried a plasmid to recombinantly produce enhanced green fluorescent protein (eGFP) upon induction. This can easily be visualized in both the bioreactor and samples by using ultraviolet light. The lab course is performed with bioreactors of the simplest design, and is therefore highly flexible, robust and easy to reproduce. As part of this work the implementation and framework, the results, the evaluation and assessment of student learning combined with opinion surveys are presented, which provides a basis for instructors intending to implement a similar lab course at their respective institution. © 2015 by the International Union of Biochemistry and Molecular Biology, 43(3):189–202, 2015.
Structural Biology Turned on Its Head
Authors: Bouvignies Guillaume , Blackledge Martin 
Published: March 2015

AbstractNMR spectroscopy and ITC have recently been combined to demonstrate how phosphorylation of the intrinsically disordered eukaryotic translation initiation factor 4E‐binding protein 2 (4E‐BP2) induces folding into a stable three‐dimensional structure. The classical structure–function paradigm is inverted, with phosphorylation‐induced folding inhibiting binding to the eukaryotic translation initiation factor 4E (eIF4E) and thereby contributing to regulation of the interaction.
Electrosynthesis of Metal–Organic Frameworks: Challenges and Opportunities
Authors: Al‐Kutubi Hanan , Gascon Jorge , Sudhölter Ernst J. R. , Rassaei Liza 
Published: March 2015

AbstractThe front cover artwork is provided by the Organic Materials & Interfaces and Catalysis Engineering Groups at Delft University of Technology (The Netherlands). The image shows the electrosynthesis of a metal–organic framework (MOF) when using anodic dissolution. The metal ions, released through electrode oxidation, combine with the linker to form the final frameworks. Read the full text of the Article at 10.1002/celc.201402429.
Ultrafast Intramolecular Relaxation and Wave‐Packet Motion in a Ruthenium‐Based Supramolecular Photocatalyst
Authors: Wächtler Maria , Guthmuller Julien , Kupfer Stephan , Maiuri Margherita , Brida Daniele , Popp Jürgen , Rau Sven , Cerullo Giulio , Dietzek Benjamin 
Published: March 2015

AbstractThe hydrogen‐evolving photocatalyst [(tbbpy)2Ru(tpphz)Pd(Cl)2]2+ (tbbpy=4,4′‐di‐tert‐butyl‐2,2′‐bipyridine, tpphz=tetrapyrido[3,2‐a:2′,3′‐c:3′′,2′′‐h:2′′′,3′′′‐j]phenazine) shows excitation‐wavelength‐dependent catalytic activity, which has been correlated to the localization of the initial excitation within the coordination sphere. In this contribution the excitation‐wavelength dependence of the early excited‐state relaxation and the occurrence of vibrational coherences are investigated by sub‐20 fs transient absorption spectroscopy and DFT/TDDFT calculations. The comparison with the mononuclear precursor [(tbbpy)2Ru(tpphz)]2+ highlights the influence of the catalytic center on these ultrafast processes. Only in the presence of the second metal center, does the excitation of a 1MLCT state localized on the central part of the tpphz bridge lead to coherent wave‐packet motion in the excited state.
Evidence of Amine–CO2 Interactions in Two Pillared‐Layer MOFs Probed by X‐ray Crystallography
Authors: Hu Xiao‐Li , Gong Qi‐Han , Zhong Rong‐Lin , Wang Xin‐Long , Qin Chao , Wang Hao , Li Jing , Shao Kui‐Zhan , Su Zhong‐Min 
Published: March 2015

AbstractTwo pillared‐layer metal–organic frameworks (MOFs; PMOF‐55 and NH2‐PMOF‐55) based on 1,2,4‐triazole and terephthalic acid (bdc)/NH2‐bdc ligands were assembled and display framework stabilities, to a certain degree, in both acid/alkaline solutions and toward water. They exhibit high CO2 uptakes and selective CO2/N2 adsorption capacities, with CO2/N2 selectivity in the range of 24–27, as calculated by the ideal adsorbed solution theory method. More remarkably, the site and interactions between the host network and the CO2 molecules were investigated by single‐crystal X‐ray diffraction, which showed that the main interaction between the CO2 molecules and PMOF‐55 is due to multipoint supramolecular interactions of CH⋅⋅⋅O, C⋅⋅⋅O, and O⋅⋅⋅O. Amino functional groups were shown to enhance the CO2 adsorption and identified as strong adsorption sites for CO2 by X‐ray crystallography.