bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combined convective and diffusive simulations: VERB‐4D comparison with 17 March 2013 Van Allen Probes observations
Authors: Shprits Yuri Y. , Kellerman Adam C. , Drozdov Alexander Y. , Spence Harlan E. , Reeves Geoffrey D. , Baker Daniel N. 
Published: September 2015

AbstractThis study is focused on understanding the coupling between different electron populations in the inner magnetosphere and the various physical processes that determine evolution of electron fluxes at different energies. Observations during the 17 March 2013 storm and simulations with a newly developed Versatile Electron Radiation Belt‐4D (VERB‐4D) are presented. Analysis of the drift trajectories of the energetic and relativistic electrons shows that electron trajectories at transitional energies with a first invariant on the scale of ~100 MeV/G may resemble ring current or relativistic electron trajectories depending on the level of geomagnetic activity. Simulations with the VERB‐4D code including convection, radial diffusion, and energy diffusion are presented. Sensitivity simulations including various physical processes show how different acceleration mechanisms contribute to the energization of energetic electrons at transitional energies. In particular, the range of energies where inward transport is strongly influenced by both convection and radial diffusion are studied. The results of the 4‐D simulations are compared to Van Allen Probes observations at a range of energies including source, seed, and core populations of the energetic and relativistic electrons in the inner magnetosphere.
Theoretical basis for operational ensemble forecasting of coronal mass ejections
Authors: Pizzo V. J. , de Koning C. , Cash M. , Millward G. , Biesecker D. A. , Puga L. , Codrescu M. , Odstrcil D. 
Published: September 2015

AbstractWe lay out the theoretical underpinnings for the application of the Wang‐Sheeley‐Arge‐Enlil modeling system to ensemble forecasting of coronal mass ejections (CMEs) in an operational environment. In such models, there is no magnetic cloud component, so our results pertain only to CME front properties, such as transit time to Earth. Within this framework, we find no evidence that the propagation is chaotic, and therefore, CME forecasting calls for different tactics than employed for terrestrial weather or hurricane forecasting. We explore a broad range of CME cone inputs and ambient states to flesh out differing CME evolutionary behavior in the various dynamical domains (e.g., large, fast CMEs launched into a slow ambient, and the converse; plus numerous permutations in between). CME propagation in both uniform and highly structured ambient flows is considered to assess how much the solar wind background affects the CME front properties at 1 AU. Graphical and analytic tools pertinent to an ensemble approach are developed to enable uncertainties in forecasting CME impact at Earth to be realistically estimated. We discuss how uncertainties in CME pointing relative to the Sun‐Earth line affects the reliability of a forecast and how glancing blows become an issue for CME off‐points greater than about the half width of the estimated input CME. While the basic results appear consistent with established impressions of CME behavior, the next step is to use existing records of well‐observed CMEs at both Sun and Earth to verify that real events appear to follow the systematic tendencies presented in this study.
Katalytische decarboxylierende Kreuzkupplung von Arylchloriden mit Benzoaten ohne aktivierende ortho‐Substituenten
Authors: Tang Jie , Biafora Agostino , Gooßen Lukas J. 
Published: September 2015

AbstractDie Einschränkung decarboxylierender Kreuzkupplungen auf ortho‐substituierte oder heterocyclische Carboxylate wurde mittels holistischer Optimierung eines dimetallischen Cu/Pd‐Katalysatorsystems überwunden. Die Kombination von CuI/Me4phen als Decarboxylierungs‐ und [(MeCN)4Pd](OTf)2/XPhos als Kreuzkupplungskatalysator ermöglicht die Synthese von Biarylen aus kostengünstigen Arylchloriden und Kaliumbenzoaten, unabhängig von ihren Substitutionsmustern.
Das Redox‐ und Koordinationsverhalten des Hexaphosphabenzol‐Liganden in [(Cp*Mo)2(μ,η6:η6‐P6)] gegenüber den “nackten” Kationen Cu+, Ag+ und Tl+
Authors: Fleischmann Martin , Dielmann Fabian , Gregoriades Laurence J. , Peresypkina Eugenia V. , Virovets Alexander V. , Huber Sebastian , Timoshkin Alexey Y. , Balázs Gábor , Scheer Manfred 
Published: September 2015

AbstractObwohl der cyclo‐P6‐Komplex [(Cp*Mo)2(μ,η6:η6‐P6)] (1) vor 30 Jahren beschrieben wurde, ist nur sehr wenig über seine Chemie bekannt. Hier berichten wir über die Synthese von Komplex 1 in hohen Ausbeuten, eines weiteren Komplexes 2, der einen beispiellosen cyclo‐P10‐Liganden besitzt, und die Reaktivität von 1 gegenüber den “nackten” Kationen Cu+, Ag+ und Tl+. Neben der Bildung der einfachen Oxidationsprodukte 3 a,b, die eine bis‐allylische Verzerrung des cyclo‐P6‐Mitteldecks zeigen, werden [M(1)2]+‐Komplexe beschrieben, die verzerrt quadratisch‐planar (M=Cu (4 a), Ag (4 b)) oder verzerrt tetraedrisch koordinierte (M=Cu (5)) M+‐Kationen aufweisen. Die verwendeten Lösungsmittel ermöglichen die Kontrolle der Reaktionsprodukte, was für Cu+ mittels Pulver‐XRD belegt wurde und durch DFT‐Rechnungen bestätigt wird. Die Reaktion mit Tl+ ergibt ein schichtartiges zweidimensionales Koordinationsnetzwerk im Festkörper.
Photoinduced Copper‐Catalyzed Regioselective Synthesis of Indoles: Three‐Component Coupling of Arylamines, Terminal Alkynes, and Quinones
Authors: Sagadevan Arunachalam , Ragupathi Ayyakkannu , Hwang Kuo Chu 
Published: September 2015

AbstractThe first successful example of a visible‐light‐induced copper‐catalyzed process for CH annulation of arylamines with terminal alkynes and benzoquinone is described. This three‐component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one‐step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom‐economical approach for the preparation of complex indoles from easily accessible starting materials under visible‐light irradiation, without the need for expensive metals and harsh reaction conditions.
Squaramide‐Catalyzed Synthesis of Enantioenriched Spirocyclic Oxindoles via Ketimine Intermediates with Multiple Active Sites
Authors: Sun Qiang‐Sheng , Zhu Hua , Chen Yong‐Jian , Yang Xiao‐Di , Sun Xing‐Wen , Lin Guo‐Qiang 
Published: September 2015

AbstractA new method for the construction of five‐membered spirocyclic oxindoles is based on a Michael–Mannich cascade reaction of a ketimine intermediated catalyzed by a bifunctional quinine‐derived squaramide. The desired products were obtained in excellent yields (up to 94 %) and stereoselectivities (up to >20:1 d.r., >99 % ee). A scaled‐up variant also proceeded smoothly showing that the one‐pot reaction might find application in the synthesis of bioactive‐compound libraries.
Everyday artefacts: subsistence and quality of life at the Prisoner Barracks, Port Arthur, Tasmania
Authors: D'Gluyas Caitlin , Gibbs Martin , Hamilton Chloe , Roe David 
Published: September 2015

ABSTRACTThis study focuses on the archaeology of the c.1835–1877 Prisoner Barracks constructed at Port Arthur, the domestic quarters for civilian, military and incarcerated occupants spanning almost the entire convict period. Faunal and artefact analyses of the assemblage uncovered at this site were used to provide a more complex understanding of institutional life. The quality of life of the occupants, and how they chose to improve it, is identified through a range of documentary and archaeological sources. It is shown that the barracks complex was a place of domestic life within the confines of an institution. It is evident in the material culture that everyday activities of occupants included the preparation of food, presentation of the home and self, manual tasks such as the production of domestic items, and recreational activities including tobacco smoking and hunting. By assessing indicators of quality of life within an institutional framework, namely the supply of local and imported goods and the material culture of recreation, this work is able to explore potential activities of the occupants that are often hidden from official records. This is examined through a number of scalar units, considering global, local and individual perspectives of the Prisoner Barracks’ landscape.
T‐shaped trichome‐specific expression of monoterpene synthase ADH2 using promoter–β‐GUS fusion in transgenic Artemisia annua L.
Authors: Fu Xueqing , Shi Pu , Shen Qian , Jiang Weimin , Tang Yueli , Lv Zongyou , Yan Tingxiang , Li Ling , Wang Guofeng , Sun Xiaofen , Tang Kexuan 
Published: September 2015

AbstractArtemisinin, a sesquiterpene lactone isolated from Artemisia annua L. (sweet wormwood), is extensively used in the treatment of malaria. In order to better understand the metabolism of terpenes in A. annua and the influence of terpene synthases on artemisinin yield, the expression pattern of a monoterpene alcohol dehydrogenase (ADH2) has been studied using transgenic plants expressing promoter–β‐glucuronidase (GUS) fusion. ADH2 played a major role in monoterpenoid biosynthesis including carveol, borneol, and artemisia ketone through in vitro biochemical analysis. In this study, the ADH2 promoter was cloned by the genome walking method. A number of putative cis‐acting elements were predicted in promoter region, suggesting that the ADH2 is driven by a complex regulation mechanism. ADH2 gene was highly expressed in old leaves, whereas the artemisinin biosynthetic genes were mainly expressed in bud and young leaves. The expression of ADH2 gene increased quickly during leaf development, revealed by qRT‐PCR. GUS expression analysis in different tissues of transgenic A. annua demonstrates that ADH2 expression is exclusively located to T‐shaped trichome, not glandular secretory trichome.
Improved expression and immobilization of Geobacillus thermoleovorans CCR11 thermostable recombinant lipase
Authors: Badillo‐Zeferino Giselle‐Lilian , Ruiz‐López Irving‐Israel , Oliart‐Ros Rosamaŕıa , Sánchez‐Otero María‐Guadalupe 
Published: September 2015

AbstractProduction of recombinant thermo‐alkali‐stable lipase LipMatCCR11, expressed in Escherichia coli BL21 (DE3), was investigated via response surface methodology by using a face‐centered design with three levels of each factor. Additionally, improvement of the catalytic performance of expressed lipase was assessed by immobilization on microporous polypropylene. Results showed that inducer (isopropyl β‐d‐1‐thiogalactopyranoside [IPTG]) concentration and temperature were found to be the significant factors (P < 0.05). The maximum lipase expression was obtained at IPTG 0.6 mM, 16 °C, and 18 H, with a specific lipase activity of 7.29 × 106 U/mg, which was 36.4 times higher (over 1,300‐fold increase) than lipase activity measured under nonoptimized conditions. On the other hand, immobilized lipase showed a high biocatalytic activity, particularly in the synthesis of aroma esters.
Associations among ancestry, geography and breast cancer incidence, mortality, and survival in Trinidad and Tobago
Authors: Warner Wayne A. , Morrison Robert L. , Lee Tammy Y. , Williams Tanisha M. , Ramnarine Shelina , Roach Veronica , Slovacek Simeon , Maharaj Ravi , Bascombe Nigel , Bondy Melissa L. , Ellis Matthew J. , Toriola Adetunji T. , Roach Allana , Llanos Adana A. M. 
Published: September 2015

AbstractBreast cancer (BC) is the most common newly diagnosed cancer among women in Trinidad and Tobago (TT) and BC mortality rates are among the highest in the world. Globally, racial/ethnic trends in BC incidence, mortality and survival have been reported. However, such investigations have not been conducted in TT, which has been noted for its rich diversity. In this study, we investigated associations among ancestry, geography and BC incidence, mortality and survival in TT. Data on 3767 incident BC cases, reported to the National Cancer Registry of TT, from 1995 to 2007, were analyzed in this study. Women of African ancestry had significantly higher BC incidence and mortality rates (Incidence: 66.96; Mortality: 30.82 per 100,000) compared to women of East Indian (Incidence: 41.04, Mortality: 14.19 per 100,000) or mixed ancestry (Incidence: 36.72, Mortality: 13.80 per 100,000). Geographically, women residing in the North West Regional Health Authority (RHA) catchment area followed by the North Central RHA exhibited the highest incidence and mortality rates. Notable ancestral differences in survival were also observed. Women of East Indian and mixed ancestry experienced significantly longer survival than those of African ancestry. Differences in survival by geography were not observed. In TT, ancestry and geographical residence seem to be strong predictors of BC incidence and mortality rates. Additionally, disparities in survival by ancestry were found. These data should be considered in the design and implementation of strategies to reduce BC incidence and mortality rates in TT.
TEM1 expression in cancer‐associated fibroblasts is correlated with a poor prognosis in patients with gastric cancer
Authors: Fujii Satoshi , Fujihara Ayano , Natori Kei , Abe Anna , Kuboki Yasutoshi , Higuchi Youichi , Aizawa Masaki , Kuwata Takeshi , Kinoshita Takahiro , Yasui Wataru , Ochiai Atsushi 
Published: September 2015

AbstractThe cancer stroma, including cancer‐associated fibroblasts (CAFs), is known to contribute to cancer cell progression and metastasis, suggesting that functional proteins expressed specifically in CAFs might be candidate molecular targets for cancer treatment. The purpose of the present study was to explore the possibility of using TEM1 (tumor endothelial marker 1), which is known to be expressed in several types of mesenchymal cells, as a molecular target by examining the impact of TEM1 expression on clinicopathological factors in gastric cancer patients. A total of 945 consecutive patients with gastric cancer who underwent surgery at the National Cancer Center Hospital East between January 2003 and July 2007 were examined using a tissue microarray approach. TEM1 expression in CAFs or vessel‐associated cells was determined using immunohistochemical staining. Three items (CAF‐TEM1‐positivity, CAF‐TEM1‐intensity, and vessel‐TEM1‐intensity) were then examined to determine the correlations between the TEM1 expression status and the recurrence‐free survival (RFS), overall survival (OS), cancer‐related survival (COS), and other clinicopathological factors. Significant correlations between CAF‐TEM1‐positivity or CAF‐TEM1‐intensity and RFS, OS, or COS were observed (P < 0.001, Kaplan–Meier curves); however, no significant correlation between vessel‐TEM1‐intensity and RFS, OS, or COS was observed. A univariate analysis showed that CAF‐TEM1‐positivity and CAF‐TEM1‐intensity were each correlated with a scirrhous subtype, tumor depth, nodal status, distant metastasis, serosal invasion, lymphatic or venous vessel infiltrations, and pTMN stage. This study suggests that the inhibition of TEM1 expression specifically in the CAFs of gastric carcinoma might represent a new strategy for the treatment of gastric cancer.
cis‐Peptide Bonds: A Key for Intestinal Permeability of Peptides?
Authors: Marelli Udaya Kiran , Ovadia Oded , Frank Andreas Oliver , Chatterjee Jayanta , Gilon Chaim , Hoffman Amnon , Kessler Horst 
Published: September 2015

AbstractRecent structural studies on libraries of cyclic hexapeptides led to the identification of common backbone conformations that may be instrumental to the oral availability of peptides. Furthermore, the observation of differential Caco‐2 permeabilities of enantiomeric pairs of some of these peptides strongly supports the concept of conformational specificity driven uptake and also suggests a pivotal role of carrier‐mediated pathways for peptide transport, especially for scaffolds of polar nature. This work presents investigations on the Caco‐2 and PAMPA permeability profiles of 13 selected N‐methylated cyclic pentaalanine peptides derived from the basic cyclo(‐D‐Ala‐Ala4‐) template. These molecules generally showed moderate to low transport in intestinal epithelia with a few of them exhibiting a Caco‐2 permeability equal to or slightly higher than that of mannitol, a marker for paracellular permeability. We identified that the majority of the permeable cyclic penta‐ and hexapeptides possess an N‐methylated cis‐peptide bond, a structural feature that is also present in the orally available peptides cyclosporine A and the tri‐N‐methylated analogue of the Veber–Hirschmann peptide. Based on these observations it appears that the presence of N‐methylated cis‐peptide bonds at certain locations may promote the intestinal permeability of peptides through a suitable conformational preorganization.
Classical Keggin Intercalated into Layered Double Hydroxides: Facile Preparation and Catalytic Efficiency in Knoevenagel Condensation Reactions
Authors: Jia Yueqing , Fang Yanjun , Zhang Yingkui , Miras Haralampos N. , Song Yu‐Fei 
Published: September 2015

AbstractThe family of polyoxometalate (POM) intercalated layered double hydroxide (LDH) composite materials has shown great promise for the design of functional materials with numerous applications. It is known that intercalation of the classical Keggin polyoxometalate (POM) of [PW12O40]3− (PW12) into layered double hydroxides (LDHs) is very unlikely to take place by conventional ion exchange methods due to spatial and geometrical restrictions. In this paper, such an intercalated compound of Mg0.73Al0.22(OH)2 [PW12O40]0.04⋅0.98 H2O (Mg3Al‐PW12) has been successfully obtained by applying a spontaneous flocculation method. The Mg3Al‐PW12 has been fully characterized by using a wide range of methods (XRD, SEM, TEM, XPS, EDX, XPS, FT‐IR, NMR, BET). XRD patterns of Mg3Al‐PW12 exhibit no impurity phase usually observed next to the (003) diffraction peak. Subsequent application of the Mg3Al‐PW12 as catalyst in Knoevenagel condensation reactions of various aldehydes and ketones with Z‐CH2‐Z′ type substrates (ethyl cyanoacetate and malononitrile) at 60 °C in mixed solvents (V2‐propanol:Vwater=2:1) demonstrated highly efficient catalytic activity. The synergistic effect between the acidic and basic sites of the Mg3Al‐PW12 composite proved to be crucial for the efficiency of the condensation reactions. Additionally, the Mg3Al‐PW12‐catalyzed Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate demonstrated the highest turnover number (TON) of 47 980 reported so far for this reaction.
A Porphyrin Coordination Cage Assembled from Four Silver(I) Triazolyl‐Pyridine Complexes
Authors: Ballester Pablo , Claudel Mickaël , Durot Stéphanie , Kocher Lucas , Schoepff Laetitia , Heitz Valérie 
Published: September 2015

AbstractThe synthesis of a zinc(II) porphyrin 1 with four appended triazolyl–pyridine chelates is reported. Complexation of the porphyrin peripheral ligands with AgI ions in a 1:2 binding stoichiometry afforded quantitatively the coordination cage [Ag4(1)2]4+. The assembly and disassembly processes of the cage were investigated in solution using UV/Vis spectroscopy. The mathematical analysis of the data obtained in the UV/Vis titration of 1 with AgI confirmed the assembly in CH2Cl2/MeOH (90:10) solution of a species having a 1:2 porphyrin/silver stoichiometry and assigned to it an overall stability constant of 5.0×1026 M−5. The use of a model system allowed an independent assessment of a microscopic binding constant value (Km) for the interaction between the triazolyl‐pyridine ligand and AgI. The coincidence that existed between the Km values extracted from the model system and the titration of 1 provided an indication of the quality and fit of the data analysis. It also allowed the calculation of the average effective molarity (EM) value for the three intramolecular processes that led to the cage assembly as 2.6 mM. Simulated speciation profiles supported the conclusion that at millimolar concentration and working under strict stoichiometric control of the silver/porphyrin ratio, the cage [Ag4(1)2]4+ was the species exclusively assembled in solution. On the other hand, when the concentration of added AgI was approximately 2.6 mM, 50 % of the coordination cage disassembled into open aggregates.
Azobenzene‐Bridged Porphyrin Nanorings: Syntheses, Structures, and Photophysical Properties
Authors: Huang Weiming , Lee Seung‐Kyu , Sung Young Mo , Peng Fulei , Yin Bangshao , Ma Ming , Chen Bo , Liu Shubin , Kirk Steven Robert , Kim Dongho , Song Jianxin 
Published: September 2015

AbstractAzobenzene‐bridged β‐to‐β and meso‐to‐meso porphyrin nanorings were successfully synthesized by a palladium‐catalyzed Suzuki–Miyaura coupling reaction in a logical synthesis. The dimeric structure was confirmed by XRD analysis. The azo linkages in di‐ and tetramers are in the all‐trans conformation, whereas in the trimers one azo linkage can be interconverted between cis and trans under external stimulation. When trimeric isomers are heated to 333 K or higher, the azo linkages will be in the all‐trans configurations: the pure all‐trans trimer can be kept in the dark for several months. Fluorescence anisotropy and pump‐power‐dependent decay results revealed excitation energy transfer for azobenzene‐bridged zinc–porphyrin nanorings. The distances between porphyrin units of these azobenzene‐bridged porphyrin arrays are almost the same, but the exciton energy hopping (EEH) times for each wheel are markedly different. The dimer and meso‐to‐meso tetramer possess relatively short excitation energy transfer (EET) times (1.28 and 2.48 ps, respectively) due to their good planarity and rigidity. In contrast, the EET time for the trimeric zinc(II)–porphyrin array (6.9 ps) is relatively long due to its nonradiative decay pathway (i.e., cis/trans isomerization of azobenzene). Both di‐ and tetramers exhibit relatively high fluorescence quantum yields, whereas the trimers show weak emission because of structural differences.
Phase‐Transfer Activation of Transition Metal Catalysts
Authors: Tuba Robert , Xi Zhenxing , Bazzi Hassan S. , Gladysz John A. 
Published: September 2015

AbstractWith metal‐based catalysts, it is quite common that a ligand (L) must first dissociate from a catalyst precursor (L′nML) to activate the catalyst. The resulting coordinatively unsaturated active species (L′nM) can either back react with the ligand in a k−1 step, or combine with the substrate in a k2 step. When dissociation is not rate determining and k−1[L] is greater than or comparable to k2[substrate], this slows the rate of reaction. By introducing a phase label onto the ligand L and providing a suitable orthogonal liquid or solid phase, dramatic rate accelerations can be achieved. This phenomenon is termed “phase‐transfer activation”. In this Concept, some historical antecedents are reviewed, followed by successful applications involving fluorous/organic and aqueous/organic liquid/liquid biphasic catalysis, and liquid/solid biphasic catalysis. Variants that include a chemical trap for the phase‐labeled ligands are also described.
A Dual‐Response Fluorescent Probe Reveals the H2O2‐Induced H2S Biogenesis through a Cystathionine β‐Synthase Pathway
Authors: Yi Long , Wei Lv , Wang Runyu , Zhang Changyu , Zhang Jie , Tan Tianwei , Xi Zhen 
Published: September 2015

AbstractThe two signaling molecules H2S and H2O2 play key roles in maintaining intracellular redox homeostasis. The biological relationship between H2O2 and H2S remains largely unknown in redox biology. In this study, we rationally designed and synthesized single‐ and dual‐response fluorescent probes for detecting both H2O2 and H2S in living cells. The dual‐response probe was shown to be capable of mono‐ and dual‐detection of H2O2 and H2S selectively and sensitively. Detailed bioimaging studies based on the probes revealed that both exogenous and endogenous H2O2 could induce H2S biogenesis in living cells. By using gene‐knockdown techniques with bioimaging, the H2S biogenesis was found to be majorly cystathionine β‐synthase (CBS)‐dependent. Our finding shows the first direct evidence on the biological communication between H2O2 (ROS) and H2S (RSS) in vivo.