bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regionalism and Changing Regional Order in the Pacific Islands
Authors: Tarte Sandra 
Published: May 2014

AbstractInstitutional developments in Pacific Islands regionalism have been dramatic in recent years. These include the changing role of the Parties to the Nauru Agreement, a grouping of eight ‘tuna‐rich’ Pacific Island states that is transforming the dynamics of regional fisheries; the emergence of a more activist Melanesian Spearhead Group, which comprises the four largest economies of the Pacific Islands and is leading the process of regional economic integration; and the establishment of the Pacific Islands Development Forum, which promises a more inclusive ‘regionalism through partnerships’ approach in addressing climate change and sustainable development issues. This new dynamism is driven by the discontent of a growing number of island states with the established regional order, defined by prevailing institutions, power and ideas, and by a desire to assert greater control over their own futures. Against the backdrop of an increasingly dynamic geopolitical and geo‐economic landscape, Pacific Island states are using alternative regional frameworks to develop new approaches to the challenges facing them.
Trinuclear [CoIII2–LnIII] (Ln=Tb, Dy) Single‐Ion Magnets with Mixed 6‐Chloro‐2‐Hydroxypyridine and Schiff Base Ligands
Authors: Liu Cai‐Ming , Zhang De‐Qing , Hao Xiang , Zhu Dao‐Ben 
Published: May 2014

AbstractThe Schiff base ligand N1,N3‐bis(3‐methoxysalicylidene)diethylenetriamine (H2valdien) and the co‐ligand 6‐chloro‐2‐hydroxypyridine (Hchp) were used to construct two 3d–4f heterometallic single‐ion magnets [Co2Dy(valdien)2(OCH3)2(chp)2]⋅ClO4⋅5 H2O (1) and [Co2Tb(valdien)2(OCH3)2(chp)2]⋅ClO4⋅2 H2O⋅CH3OH (2). The two trinuclear [CoIII2LnIII] complexes behave as a mononuclear LnIII magnetic system because of the presence of two diamagnetic cobalt(III) ions. Complex 1 has a molecular symmetry center, and it crystallizes in the C2/c space group, whereas complex 2 shows a lower molecular symmetry and crystallizes in the P21/c space group. Magnetic investigations indicated that both complexes are field‐induced single‐ion magnets, and the CoIII2–DyIII complex possesses a larger energy barrier [74.1(4.2) K] than the CoIII2–TbIII complex [32.3(2.6) K].
Cooperative Catalysis: Electron‐Rich FeH Complexes and DMAP, a Successful “Joint Venture” for Ultrafast Hydrogen Production
Authors: Rommel Susanne , Hettmanczyk Lara , Klein Johannes E. M. N. , Plietker Bernd 
Published: May 2014

AbstractA series of defined iron–hydrogen complexes was prepared in a straightforward one‐pot approach. The structure and electronic properties of such complexes were investigated by means of quantum‐chemical analysis. These new complexes were then applied in the dehydrogenative silylation of methanol. The complex (dppp)(CO)(NO)FeH showed a remarkable activity with a TOF of more than 600 000 h−1 of pure hydrogen gas within seconds.
Multiple testing in fMRI: An empirical case study on the balance between sensitivity, specificity, and stability
Authors: Durnez Joke , Roels Sanne P. , Moerkerke Beatrijs 
Published: May 2014

Functional Magnetic Resonance Imaging is a widespread technique in cognitive psychology that allows visualizing brain activation. The data analysis encompasses an enormous number of simultaneous statistical tests. Procedures that either control the familywise error rate or the false discovery rate have been applied to these data. These methods are mostly validated in terms of average sensitivity and specificity. However, procedures are not comparable if requirements on their error rates differ. Moreover, less attention has been given to the instability or variability of results. In a simulation study in the context of imaging, we first compare the Bonferroni and Benjamini–Hochberg procedures. Considering Bonferroni as a way to control the expected number of type I errors enables more lenient thresholding compared to familywise error rate control and a direct comparison between both procedures. We point out that while the same balance is obtained between average sensitivity and specificity, the Benjamini–Hochberg procedure appears less stable. Secondly, we have implemented the procedure of Gordon et al. () (originally proposed for gene selection) that includes stability, measured through bootstrapping, in the decision criterion. Simulations indicate that the method attains the same balance between sensitivity and specificity. It improves the stability of Benjamini–Hochberg but does not outperform Bonferroni, making this computationally heavy bootstrap procedure less appealing. Third, we show how stability of thresholding procedures can be assessed using real data. In a dataset on face recognition, we again find that Bonferroni renders more stable results.
A 1,2‐propylene oxide sensor utilizing cataluminescence on CeO2 nanoparticles
Authors: Liu Hongmei , Zhang Yantu , Zhen Yanzhong , Ma Yuan , Zuo Weiwei 
Published: May 2014

ABSTRACTA simple and sensitive gas sensor was proposed for the determination of 1,2‐propylene oxide (PO) based on its cataluminescence (CTL) by oxidation in the air on the surface of CeO2 nanoparticles. The luminescence characteristics and optimal conditions were investigated in detail. Under optimized conditions, the linear range of the CTL intensity versus the concentration of PO was 10–150 ppm, with a correlation coefficient (r) of 0.9974 and a limit of detection (S/N = 3) of 0.9 ppm. The relative standard deviation for 40 ppm PO was 1.2% (n = 7). There was no or only weak response to common foreign substances including acetone, formaldehyde, ethyl acetate, acetic acid, chloroform, propanol, carbon tetrachloride, ether and methanol. There was no significant change in the catalytic activity of the sensor for 100 h. The proposed method was simple and sensitive, with a potential of detecting PO in the environment and industry. Copyright © 2014 John Wiley & Sons, Ltd.
Applications of micelle enhancement in luminescence‐based analysis
Authors: Alarfaj Nawal A. , El‐Tohamy Maha F. 
Published: May 2014

AbstractMicelles are self‐assembled aggregates that arrange themselves into spheres in aqueous media. When the surfactant concentration reaches the critical micelle concentration, extensive aggregation of the surfactant monomers occurs to form micelles. A micelle has both a hydrophilic and a hydrophobic part. This allows them to form a spherical shape and for their glycolipid and phospholipid components to form lipid bilayers. The importance of micelles is increasing because of their wide analytical applications. Recently, colloidal carrier systems have received much attention in the field of analytical chemistry, especially in luminescence enhancement applications. Copyright © 2014 John Wiley & Sons, Ltd.
Predicting pneumonia mortality using CURB‐65, PSI, and patient characteristics in patients presenting to the emergency department of a comprehensive cancer center
Authors: Gonzalez Carmen , Johnson Tami , Rolston Kenneth , Merriman Kelly , Warneke Carla , Evans Scott 
Published: May 2014

AbstractThe prognostic accuracy of the CURB‐65 criteria and pneumonia severity index (PSI) in immunocompromised cancer patients with pneumonia is unknown. We sought to determine whether CURB‐65 and PSI predict 28‐day mortality in cancer patients with pneumonia, and identify other factors that predispose cancer patients with pneumonia to a high mortality risk. We assessed sensitivities, specificities, predictive values, and areas under the receiver operating curve area under the curve (AUC) of the CURB‐65 and PSI in predicting the 28‐day mortality of cancer patients presenting to our institution's emergency department with pneumonia. We used the DeLong and Clarke–Pearson approach to determine whether the addition of other risk factors improved the scales' performances. The overall and pneumonia‐related 28‐day mortality rates were 20.2% (n = 44) and 17.4% (n = 38), respectively. In predicting 28‐day mortality, the CURB‐65 score had sensitivity of 45% and specificity of 81%, and the PSI score had sensitivity of 82% and specificity of 34%. The CURB‐65 and PSI discriminated poorly between fatal and nonfatal pneumonia cases (AUCs, 0.664 and 0.658, respectively; 95% confidence interval [CI], 0.57–0.75 for each). The addition of radiation therapy (RT) within 4 weeks and stem cell transplant (SCT) significantly improved the AUCs of the CURB‐65 (0.75; 95% CI, 0.67–0.83) and PSI (0.73; 95% CI, 0.65‐0.82). Inadequate performances of CURB‐65 and PSI demonstrate that a tool for predicting pneumonia‐related mortality in cancer patients and other immunocompromised populations is needed. Pneumonia patients who have undergone recent RT or (SCT) are at a high risk of dying from pneumonia and require special consideration when assessing pneumonia‐related mortality risk.
Induction of dedifferentiated male mouse adipose stromal vascular fraction cells to primordial germ cell‐like cells
Authors: Cui Guanghui , Qi Zhengyu , Zhang Yanmin , Long Xia , Qin Jie , Guo Xin 
Published: May 2014

AbstractThe adipose stromal vascular fraction (SVF) contains abundant mesenchymal stem cell populations that have a limited ability to self‐renew and differentiate. Male mouse adipose SVF cells were dedifferentiated by reprogramming factors (c‐Myc, Oct4, Sox2, and Klf4) to form embryonic stem cell‐like cells (ESCLCs), which upgraded their limited differentiation potential. The ESCLCs were induced to differentiate toward epiblast‐like cells (EpiLCs) and primordial germ cell‐like cells (PGCLCs) by culturing in media supplied with activin A and BMP‐4, respectively. The derived ESCLCs possess embryonic stem cell features and can automatically form embryonic bodies. After culture in EpiLC induction medium for 2–3 days, ESCLCs formed flattened epithelial structures that were different from their original water drop‐like colonies, and the expression of pluripotency‐related genes decreased. When the cells that had been cultured in EpiLC induction medium for 2 days were isolated and cultured in PGCLC induction medium for 4–6 days, they formed typical water drop‐like colonies again. Moreover, expression of the pluripotency‐related genes and the primordial germ cell (PGC) specification‐related genes increased. During progression from ESCLCs toward EpiLCs and PGCLCs, the levels of histone methylases H3K9me2 and H3K27me3 kept changing, which resembled those seen in PGC specification. The derived PGCLCs expressed SSEA‐1, Blimp‐1, and Stella. Furthermore, methylation of Igf2r and Snrpn was retained, but H19 and Kcnq1ot1 methylation levels were slightly reduced compared to non‐PGCLCs, suggesting that the derived PGCLCs may have initiated the process of imprint erasure.
On Ammonia Binding to the Oxygen‐Evolving Complex of Photosystem II: A Quantum Chemical Study
Authors: Schraut Johannes , Kaupp Martin 
Published: May 2014

AbstractA recent EPR study (M. Perrez Navarro et al., Proc. Natl. Acad. Sci.­ 2013, 110, 15561) provided evidence that ammonia binding to the oxygen‐evolving complex (OEC) of photosystem II in its S2 state takes place at a terminal‐water binding position (W1) on the “dangler” manganese center MnA. This contradicted earlier interpretations of 14N electron‐spin‐echo envelope modulation (ESEEM) and extended X‐ray absorption fine‐structure (EXAFS) data, which were taken to indicate replacement of a bridging oxo ligand by an NH2 unit. Here we have used systematic broken‐symmetry density functional theory calculations on large (ca. 200 atom) model clusters of an extensive variety of substitution patterns and core geometries to examine these contradictory pieces of evidence. Computed relative energies clearly favor the terminal substitution pattern over bridging‐ligand arrangements (by about 20–30 kcal mol−1) and support W1 as the preferred binding site. Computed 14N EPR nuclear‐quadrupole coupling tensors confirm previous assumptions that the appreciable asymmetry may be accounted for by strong, asymmetric hydrogen bonding to the bound terminal NH3 ligand (mainly by Asp61). Indeed, bridging NH2 substitution would lead to exaggerated asymmetries. Although our computed structures confirm that the reported elongation of an Mn–Mn distance by about 0.15 Å inferred from EXAFS experiments may only be reproduced by bridging NH2 substitution, it seems possible that the underlying EXAFS data were skewed by problems due to radiation damage. Overall, the present data clearly support the suggested terminal NH3 coordination at the W1 site. The finding is significant for the proposed mechanistic scenarios of OEC catalysis, as this is not a water substrate site, and effects of this ammonia binding on catalysis thus must be due to more indirect influences on the likely substrate binding site at the O5 bridging‐oxygen position.
Carborane Dyads for Photoinduced Electron Transfer: Photophysical Studies on Carbazole and Phenyl‐o‐carborane Molecular Assemblies
Authors: Kwon Soonnam , Wee Kyung‐Ryang , Cho Yang‐Jin , Kang Sang Ook 
Published: May 2014

Abstracto‐Carborane‐based donor–acceptor dyads comprising an o‐carboranyl phenyl unit combined with N‐carbazole (1) or 4‐phenyl‐N‐carbazole (2) were prepared, and their dyad characters were confirmed by steady‐state photochemistry and photodynamic experiments as well as electrochemical studies. The absorption and electrochemical properties of the dyads were essentially the sum of those of the carbazole and o‐carboranyl phenyl units; this indicates negligible interaction between the carbazole and o‐carborane units in the ground state. However, the emission spectra of 1 and 2 indicated that carbazole fluorescence was effectively quenched and a new charge‐transfer (CT) emission was observed in solvents, varying from hexane to acetonitrile, which exhibited large Stoke shifts. The CT emission properties of o‐carborane‐based dyads were further analyzed by using Lippert–Mataga plots to show that unit charge separation occurred to form a charge‐separated species in the excited state, namely, 1⋅2. This excited‐state species was confirmed by nanosecond transient absorption spectra and spectroelectrochemical measurements; the photoexcitation of carbazole generated the CT state in which a radical cation and anion were formed at the carbazole and o‐carborane units, respectively, within a few nanoseconds. DFT calculations corroborated the presence of this CT species and showed localized populations of the highest singly occupied molecular orbital on 2 in the reduced anionic state. As a result, molecular assemblies formed by linking the carbazole group with the o‐carborane cage through a phenylene or multi‐phenylene spacer revealed that the photoinduced electron‐transfer process occurred intramolecularly.
Intercalation Study of Low‐Molecular‐Weight Hyperbranched Polyethyleneimine into Graphite Oxide
Authors: Tsoufis Theodoros , Katsaros Fotios , Sideratou Zili , Kooi Bart J. , Karakassides Michael. A. , Siozios Anastasios 
Published: May 2014

AbstractWe report for the first time the intercalation of low‐molecular‐weight hyperbranched polyethyleneimine (PEI) into graphite oxide (GO) for the facile, bulk synthesis of novel graphene‐based hybrid (GO‐PEI) materials exhibiting tailored interlayer galleries. The size of the intercalant as well as the loading in GO were systematically investigated to determine their contribution to the basal spacing of the resulting materials. Powder X‐ray diffraction measurements demonstrated the generation of constrained hybrid systems along the c axis that exhibit considerably increased interlayer distances compared with the starting, pristine GO. The results of X‐ray photoelectron and FTIR studies are consistent with a “grafting‐to” process of the intercalated PEI with the oxygen functional groups present along the GO framework. Furthermore, it was found that a great number of the nitrogen‐containing groups in PEI still remain available within the newly formed, confined micro‐environment of intercalated GO galleries. The increased surface area of the GO‐PEI hybrids in conjunction with the remaining available active groups of intercalated PEI render the synthesised hybrids very attractive candidates as nanostructured adsorbents.
Hierarchically Ordered Self‐Assembly of Amphiphilic Bifullerenes
Authors: Wasserthal Lennard , Schade Boris , Ludwig Kai , Böttcher Christoph , Hirsch Andreas 
Published: May 2014

AbstractA series of novel functionalised dumbbell‐shaped bifullerenes in which two [5.0] pentakis‐adducts of C60 are covalently connected by cyclic bismalonates were synthesised. These dimeric compounds, carrying various combinations of hydrophilic and hydrophobic addends, self‐assemble in aqueous solution towards supramolecular architectures of different structural complexity as observed by cryogenic transmission electron microscopy (cryo‐TEM). The detailed analysis of the image data revealed an unprecedented hierarchical aggregation behaviour. Whereas completely hydrophilic substituted bifullerenes formed profoundly monodisperse populations of small oligomeric elementary micelles consisting of only three or four bifullerene molecules in a supposedly bent conformation, their amphiphilic equivalents underwent a hierarchical two‐step assembly process towards larger spherical and even rod‐like structures. The data suggest that the hierarchical assembly process is driven by hydrophobic interactions of preformed tetrameric elementary micelles.
Development of a Ruthenium/Phosphite Catalyst System for Domino Hydroformylation–Reduction of Olefins with Carbon Dioxide
Authors: Liu Qiang , Wu Lipeng , Fleischer Ivana , Selent Detlef , Franke Robert , Jackstell Ralf , Beller Matthias 
Published: May 2014

AbstractInvited for the cover of this issue is the group of Matthias Beller at the Leibniz‐Institut für Katalyse e.V. an der Universität Rostock. The image depicts how ruthenium catalysts can effectively decreases the activation energy to promote the activation of CO2. Read the full text of the article at 10.1002/chem.201400358.
A Multifunctional Magnetic Material under Pressure
Authors: Rodríguez‐Velamazán J. Alberto , Fabelo Oscar , Beavers Christine M. , Natividad Eva , Evangelisti Marco , Roubeau Olivier 
Published: May 2014

AbstractFeII(Metz)6](FeIIIBr4)2 (Metz=1‐methyltetrazole) is one of the rare systems combining spin‐crossover and long‐range magnetic ordering. A joint neutron and X‐ray diffraction and magnetometry study allows determining its collinear antiferromagnetic structure, and shows an increase of the Néel temperature from 2.4 K at ambient pressure, to 3.9 K at 0.95 GPa. Applied pressure also enables a full high‐spin to low‐spin switch at ambient temperature.
3,3′‐Bi(1,2,4‐oxadiazoles) Featuring the Fluorodinitromethyl and Trinitromethyl Groups
Authors: Kettner Marcos A. , Karaghiosoff Konstantin , Klapötke Thomas M. , Sućeska Muhamed , Wunder Swetlana 
Published: May 2014

AbstractHere we report on the preparation of two hydrogen atom free 3,3′‐bi(1,2,4‐oxadiazole) derivatives. 5,5′‐Bis(fluorodinitromethyl)‐3,3′‐bi(1,2,4‐oxadiazole) was synthesised by fluorination of diammonium 5,5′‐bis(dinitromethanide)‐3,3′‐bi(1,2,4‐oxadiazole). For our previously reported analogue 5,5′‐bis(trinitromethyl)‐3,3′‐bi(1,2,4‐oxadiazole), a new synthetic route starting from new 3,3′‐bi(1,2,4‐oxadiazolyl)‐5,5′‐diacetic acid was developed. In this course also hitherto unknown 5,5′‐dimethyl‐3,3′‐bi(1,2,4‐oxadiazole) was isolated. The compounds were characterised by multinuclear NMR spectroscopy, IR and Raman spectroscopy, elemental analysis as well as mass spectrometry. X‐ray diffraction studies were performed and the crystal structures for the 5,5'‐dimethyl and 5,5'‐(fluorodinitromethyl) derivatives are reported. The energetic 5,5'‐(fluorodinitromethyl) and 5,5'‐(trinitromethyl) compounds do not contain any hydrogen atoms and show remarkable high densities. Furthermore, the thermal stabilities and sensitivities were determined by differential scanning calorimetry (DSC) and standardised impact and friction tests. The heats of formation were calculated by the atomisation method based on CBS‐4M enthalpies. With these values and the room‐temperature X‐ray densities, several detonation and propulsion parameters, such as the detonation velocity and pressure as well as the specific impulse of mixtures with aluminium, were computed using the EXPLO5 code.
Cross‐Conjugated Hexaphyrins and Their Bis‐Rhodium Complexes
Authors: Naoda Koji , Sung Young Mo , Lim Jong Min , Kim Dongho , Osuka Atsuhiro 
Published: May 2014

AbstractA cross‐conjugated hexaphyrin that carries two meso‐oxacyclohexadienylidenyl (OCH) groups 9 was synthesized from the condensation of 5,10‐bis(pentafluorophenyl)tripyrrane with 3,5‐di‐tert‐butyl‐4‐hydroxybenzaldehyde. The reduction of 9 with NaBH4 afforded the Möbius aromatic [28]hexaphyrin 10. Bis‐rhodium complex 11, prepared from the reaction of 10 with [{RhCl(CO)2}2], displays strong Hückel antiaromatic character because of the 28 π electrons that occupy the conjugated circuit on the enforced planar structure. The oxidation of 11 with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) yielded complexes 12 and 13 depending upon the reaction conditions. Both 12 and 13 are planar owing to bis‐rhodium metalation. Although complex 12 bears two meso‐OCH groups at the long sides and is quinonoidal and nonaromatic in nature, complex 13 bears 3,5‐di‐tert‐butyl‐4‐hydroxyphenyl and OCH groups and exhibits a moderate diatropic ring current despite its cross‐conjugated electronic circuit. The diatropic ring current increases upon increasing the solvent polarity, most likely due to an increased contribution of an aromatic zwitterionic resonance hybrid.
Supramolecular Tetrad Featuring Covalently Linked Bis(porphyrin)–Phthalocyanine Coordinated to Fullerene: Construction and Photochemical Studies
Authors: KC Chandra B. , Lim Gary N. , Karr Paul A. , D'Souza Francis 
Published: May 2014

AbstractA multimodular donor–acceptor tetrad featuring a bis(zinc porphyrin)–(zinc phthalocyanine) ((ZnP–ZnP)–ZnPc) triad and bis‐pyridine‐functionalized fullerene was assembled by a “two‐point” binding strategy, and investigated as a charge‐separating photosynthetic antenna‐reaction center mimic. The spectral and computational studies suggested that the mode of binding of the bis‐pyridine‐functionalized fullerene involves either one of the zinc porphyrin and zinc phthalocyanine (Pc) entities of the triad or both zinc porphyrin entities leaving ZnPc unbound. The binding constant evaluated by constructing a Benesi–Hildebrand plot by using the optical data was found to be 1.17×105 M−1, whereas a plot of “mole‐ratio” method revealed a 1:1 stoichiometry for the supramolecular tetrad. The mode of binding was further supported by differential pulse voltammetry studies, in which redox modulation of both zinc porphyrin and zinc phthalocyanine entities was observed. The geometry of the tetrad was deduced by B3LYP/6‐31G* optimization, whereas the energy levels for different photochemical events was established by using data from the optical absorption and emission, and electrochemical studies. Excitation of the zinc porphyrin entity of the triad and tetrad revealed ultrafast singlet–singlet energy transfer to the appended zinc phthalocyanine. The estimated rate of energy transfer (kENT) in the case of the triad was found to be 7.5×1011 s−1 in toluene and 6.3×1011 s−1 in o‐dichlorobenzene, respectively. As was predicted from the energy levels, photoinduced electron transfer from the energy‐transfer product, that is, singlet‐excited zinc phthalocyanine to fullerene was verified from the femtosecond‐transient spectral studies, both in o‐dichlorobenzene and toluene. Transient bands corresponding to ZnPc⋅+ in the 850 nm range and C60⋅− in the 1020 nm range were clearly observed. The rate of charge separation, kCS, and rate of charge recombination, kCR, for the (ZnP–ZnP)–ZnPc⋅+:Py2C60⋅− radical ion pair (from the time profile of 849 nm peak) were found to be 2.20×1011 and 6.10×108 s−1 in toluene, and 6.82×1011 and 1.20×109 s−1 in o‐dichlorobenzene, respectively. These results revealed efficient energy transfer followed by charge separation in the newly assembled supramolecular tetrad.