bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Reaction Mechanism of the Complete Intermolecular O2 Transfer between Mononuclear Nickel and Manganese Complexes with Macrocyclic Ligands
Authors: Zapata‐Rivera Jhon , Caballol Rosa , Calzado Carmen J. , Liakos Dimitrios G. , Neese Frank 
Published: September 2014

AbstractThe recently described intermolecular O2 transfer between the side‐on Ni‐O2 complex [(12‐TMC)Ni‐O2]+ and the manganese complex [(14‐TMC)Mn]2+, where 12‐TMC and 14‐TMC are 12‐ and 14‐membered macrocyclic ligands, 12‐TMC=1,4,7,10‐tetramethyl‐1,4,7,10‐tetraazacyclododecane and 14‐TMC=1,4,8,11‐tetramethyl‐1,4,8,11‐tetraazacyclotetradecane, is studied by means of DFT methods. B3LYP calculations including long‐range corrections and solvent effects are performed to elucidate the mechanism. The potential energy surfaces (PESs) compatible with different electronic states of the reactants have been analyzed. The calculations confirm a two‐step reaction, with a first rate‐determining bimolecular step and predict the exothermic character of the global process. The relative stability of the products and the reverse barrier are in line with the fact that no reverse reaction is experimentally observed. An intermediate with a μ‐η1:η1‐O2 coordination and two transition states are identified on the triplet PES, slightly below the corresponding stationary points of the quintet PES, suggesting an intersystem crossing before the first transition state. The calculated activation parameters and the relative energies of the two transition sates and the products are in very good agreement with the experimental data. The calculations suggest that a superoxide anion is transferred during the reaction.
Domino‐Hydroformylation/Aldol Condensation Catalysis: Highly Selective Synthesis of α,β‐Unsaturated Aldehydes from Olefins
Authors: Fang Xianjie , Jackstell Ralf , Franke Robert , Beller Matthias 
Published: September 2014

AbstractA general and highly chemo‐, regio‐, and stereoselective synthesis of α,β‐unsaturated aldehydes by a domino hydroformylation/aldol condensation reaction has been developed. A variety of olefins and aromatic aldehydes were efficiently converted into various substituted α,β‐unsaturated aldehydes in good to excellent yields in the presence of a rhodium phosphine/acid–base catalyst system. In view of the easy availability of the substrates, the high atom‐efficiency, the excellent selectivity, and the mild conditions, this method is expected to complement current methodologies for the preparation of α,β‐unsaturated aldehydes.
New Insight into the Hydrocarbon‐Pool Chemistry of the Methanol‐to‐Olefins Conversion over Zeolite H‐ZSM‐5 from GC‐MS, Solid‐State NMR Spectroscopy, and DFT Calculations
Authors: Wang Chao , Chu Yueying , Zheng Anmin , Xu Jun , Wang Qiang , Gao Pan , Qi Guodong , Gong Yanjun , Deng Feng 
Published: September 2014

AbstractOver zeolite H‐ZSM‐5, the aromatics‐based hydrocarbon‐pool mechanism of methanol‐to‐olefins (MTO) reaction was studied by GC‐MS, solid‐state NMR spectroscopy, and theoretical calculations. Isotopic‐labeling experimental results demonstrated that polymethylbenzenes (MBs) are intimately correlated with the formation of olefin products in the initial stage. More importantly, three types of cyclopentenyl cations (1,3‐dimethylcyclopentenyl, 1,2,3‐trimethylcyclopentenyl, and 1,3,4‐trimethylcyclopentenyl cations) and a pentamethylbenzenium ion were for the first time identified by solid‐state NMR spectroscopy and DFT calculations under both co‐feeding ([13C6]benzene and methanol) conditions and typical MTO working (feeding [13C]methanol alone) conditions. The comparable reactivity of the MBs (from xylene to tetramethylbenzene) and the carbocations (trimethylcyclopentenyl and pentamethylbenzium ions) in the MTO reaction was revealed by 13C‐labeling experiments, evidencing that they work together through a paring mechanism to produce propene. The paring route in a full aromatics‐based catalytic cycle was also supported by theoretical DFT calculations.
Droplet Separation from the Gas Phase in Small‐Scale Ring Chamber Centrifuges
Authors: Piesche Manfred , Junker Malte , Grabe Cornelia 
Published: September 2014

AbstractHier werden laminare Strömungsvorgänge in kleinskaligen Ringkammerzentrifugen untersucht, um das Abscheideverhalten von Ölaerosolen mithilfe von Modellregeln und Ähnlichkeitsgesetzen zu beschreiben. Dabei sind die Ermittlung des Trenngrades in Abhängigkeit der Zentrifugengeometrie, die Stoffeigenschaften der kontinuierlichen und dispersen Phasen sowie Betriebsparameter wie Winkelgeschwindigkeit und Volumenstrom von Interesse. Zudem wurden experimentelle Untersuchungen durchgeführt, um den Gültigkeitsbereich, die Brauchbarkeit und die Genauigkeit der Rechenmodelle zu bewerten.
Preparation of Coals for Negativ‐Ion Laser Desorption/Ionization Mass Spectrometry
Authors: Kroll Marius Matthias , Otto Matthias 
Published: September 2014

AbstractFür die Negativ‐Ionen‐Laserdesorptions‐Ionisations‐Massenspektrometrie von Kohlen existiert nur eine geringe Anzahl an Präparationsmethoden, die jedoch eine geringe Probenkapazität aufweisen. In dieser Arbeit wird daher eine neue Probenpräparationsmethode für Kohlen vorgestellt. Dabei wird die Probe als Dispersion mit Glycerin oder Polyethylenglycol 400 und Wasser auf einen Probeträger aufgebracht. Die Messungen dieser Präparate zeigen eine hohe Probenkapazität, sind stabil und liefern gut reproduzierbare Ergebnisse.
Color scheme adjustment by fuzzy constraint satisfaction for color vision deficiencies
Authors: Yanagida Takuto , Okajima Katsunori , Mimura Hidenori 
Published: September 2014

AbstractColor schemes or color combinations are widely used in printed materials and their digital versions, including web pages. These schemes convey information and create aesthetic appeal. Consequently, graphic designers have to strike a balance between accessibility and aesthetics with the color schemes they select. However, certain color schemes make the represented information confusing when viewers have color vision deficiencies (CVDs), which may lead to decrease in discriminability between used colors. What we will call the color‐scheme‐recoloring problem is the difficulty of optimizing a color scheme so as to preserve its original design and yet be simultaneously discriminable for all viewers, with or without CVDs. To address the problem, we formulated it within a framework of a fuzzy constraint satisfaction problem, a technique of artificial intelligence, and developed a tool for graphic designers. By utilizing the practical color co‐ordinate system (PCCS), we introduce concepts used in the field of graphic design. This work combines pre‐publication recoloring techniques for CVD viewers with elements of artificial intelligence, psychophysics, and psychology. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 446–464, 2015
De Novo Design of an Endohedral Heteronuclear Dimetallofullerene (UGd)@C60 with Exceptional Structural and Electronic Properties
Authors: Dai Xing , Han Jie , Gao Yang , Wang Zhigang 
Published: September 2014

AbstractEver since the first synthesis of La@C82 and U@C28, there has been a growing interest in the study of endohedral metallofullerenes (EMFs) because of their great potential in various applications. Here we design a novel heteronuclear EMF (U‐Gd)@C60, by using density functional theory (DFT), which shows an encapsulation energy of about −5.53 eV, comparable to that of U2@C60, La2@C80, and Lu2@C76. (U‐Gd)@C60 is found to have a surprising twofold, single‐electron UGd bond that results from the strong nanoconfinement of the fullerene, dominated by uranium′s 5f and 6d and gadolinium′s 5d atomic orbitals. The ground state shows an 11‐et high spin state, and the net spins distributed on the U‐pole carbons are relatively scattered, while they are highly concentrated on the Gd‐pole carbons. The exceptional electronic characteristics of this novel EMF, containing both uranium and gadolinium atoms encapsulated, might prove useful for future applications in nuclear energy and biomedicine.
The Lineshape of the Electronic Spectrum of the Green Fluorescent Protein Chromophore, Part I: Gas Phase
Authors: Davari Mehdi D. , Ferrer Francisco J. Avila , Morozov Dmitry , Santoro Fabrizio , Groenhof Gerrit 
Published: September 2014

AbstractIn this work we present the vibrationally resolved optical absorption spectrum of p‐hydroxybenzylidene‐2,3‐dimethylimidazolinone (HBDI), the green fluorescent protein (GFP) chromophore, computed at several levels of theory, including time‐dependent DFT with various functionals and basis sets, CASSCF, CASPT2 and XMCQDPT2. We also investigated what happens to the spectrum if the ground‐ and excited‐state geometries are optimized at different levels of theory (mixed approach), as has been used previously. The vibrationally resolved absorption spectra obtained by DFT, CASPT2 and XMCQDPT2 are very similar and consist of a main absorption peak and a shoulder that is ∼1500 cm−1 higher in energy. The vibrational progression increases moderately with temperature. These spectra are in qualitative agreement with experimental action spectra, but much narrower and lack the long tail in the blue, even at high temperatures. Because our calculated emission spectra, which are equally narrow, are in good agreement with the emission of green fluorescent protein at 253 K, we argue that the action spectrum are too broad to be considered as the absorption spectrum. The CASSCF method and the mixed approaches overestimate the vibrational progressions with respect to CAM‐B3LYP, CASPT2 and XMCQDPT2, due to inaccuracies in the geometric S0→S1 displacements. Finally, we computed the vibronic spectra of four chromophore analogues with different substitutions on the rings and found that these substitutions hardly affect the lineshape in vacuum.
Ferrofluids: Synthetic Strategies, Stabilization, Physicochemical Features, Characterization, and Applications
Authors: Joseph Aswathy , Mathew Suresh 
Published: September 2014

AbstractFerrofluids (FFs) or magnetic nanofluids are incredible smart materials consisting of ultrafine magnetic nanoparticles suspended in a liquid carrier medium, which exhibit both fluidity and magnetic controllability. Studies involving the dynamics and physicochemical properties of these magnetic nanofluids are an interdisciplinary area of research attracting researchers from different fields of science and technology. Herein, a comprehensive Review on the different aspects of FF research is presented. First, the synthesis and stabilization of various types of FFs are discussed followed by their physicochemical features such as polydispersity, magnetic behavior, dipolar interactions, formation of chainlike aggregates, and long‐range ordering. The Review also details the rheological and thermal properties, dynamic instabilities, phase behavior, and particle assemblies in FFs to form complex multipolar geometries, photonic nanostructures, labyrinth structures, thin films, and droplets. Many important characterization techniques for probing FF properties are also briefly discussed, and the numerous innovative applications and future prospects of FFs are outlined.
Nickel Complex with Internal Bases as Efficient Molecular Catalyst for Photochemical H2 Production
Authors: Yang Yong , Wang Mei , Xue Liqin , Zhang Fengbo , Chen Lin , Ahlquist Mårten S. G. , Sun Licheng 
Published: September 2014

AbstractA Ni complex with internal bases that contain bipyridine‐derived ligands, [Ni(L)2(H2O)2](BF4)2 ([1](BF4)2, L=2‐(2‐pyridyl)‐1,8‐naphthyridine), and a reference complex that bears analogous bipyridine‐derived ligands but without an internal base, [Ni(L′)3](BF4)2 ([2](BF4)2, L′=2‐(2‐pyridyl)quinoline), were synthesized and characterized. The electrochemical properties of these complexes were studied in CH3CN, H2O, and a mixture of EtOH/H2O. The fluorescence spectroscopic studies suggest that both dynamic and the sphere‐of‐action static quenching exist in the fluorescein Fl2−/[1]2+ and Fl2−/[2]2+ systems. These noble‐metal‐free molecular systems were studied for photocatalytic H2 generation. Under optimal conditions, the turnover number of H2 evolution reaches 3230 based on [1]2+, whereas [2]2+ displays only approximately one third of the turnover of [1]2+. A plausible mechanism for the catalytic H2 generation by [1]2+ is presented based on DFT calculations.
Whole‐mount fluorescent in situ hybridization staining of the colonial tunicate Botryllus schlosseri
Authors: Langenbacher Adam D. , Rodriguez Delany , Di Maio Alessandro , De Tomaso Anthony W. 
Published: September 2014

SummaryBotryllus schlosseri is a colonial ascidian with characteristics that make it an attractive model for studying immunology, stem cell biology, evolutionary biology, and regeneration. Transcriptome sequencing and the recent completion of a draft genome sequence for B. schlosseri have revealed a large number of genes, both with and without vertebrate homologs, but analyzing the spatial and temporal expression of these genes in situ has remained a challenge. Here, we report a robust protocol for in situ hybridization that enables the simultaneous detection of multiple transcripts in whole adult B. schlosseri using Tyramide Signal Amplification in conjunction with digoxigenin‐ and dinitrophenol‐labeled RNA probes. Using this protocol, we have identified a number of genes that can serve as markers for developing and mature structures in B. schlosseri, permitting analysis of phenotypes induced in loss‐of‐function experiments. genesis 53:194–201, 2015. © 2014 Wiley Periodicals, Inc.
The role of calcium and predation on plate morph evolution in the three‐spined stickleback (Gasterosteus aculeatus)
Authors: Smith Carl , Spence Rowena , Barber Iain , Przybylski Mirosław , Wootton Robert J. 
Published: September 2014

AbstractWhile the genetic basis to plate morph evolution of the three‐spined stickleback (Gasterosteus aculeatus) is well described, the environmental variables that select for different plate and spine morphs are incompletely understood. Using replicate populations of three‐spined sticklebacks on North Uist, Scotland, we previously investigated the role of predation pressure and calcium limitation on the adaptive evolution of stickleback morphology and behavior. While dissolved calcium proved a significant predictor of plate and spine morph, predator abundance did not. Ecol. Evol., xxx, 2014 and xxx performed a comparable analysis to our own to address the same question. They failed to detect a significant effect of dissolved calcium on morphological evolution, but did establish a significant effect of predation; albeit in the opposite direction to their prediction.
Historical land‐use and landscape change in southern Sweden and implications for present and future biodiversity
Authors: Cui Qiao‐Yu , Gaillard Marie‐José , Lemdahl Geoffrey , Stenberg Li , Sugita Shinya , Zernova Ganna 
Published: September 2014

AbstractThe two major aims of this study are (1) To test the performance of the Landscape Reconstruction Algorithm (LRA) to quantify past landscape changes using historical maps and related written sources, and (2) to use the LRA and map reconstructions for a better understanding of the origin of landscape diversity and the recent loss of species diversity. Southern Sweden, hemiboreal vegetation zone. The LRA was applied on pollen records from three small bogs for four time windows between AD 1700 and 2010. The LRA estimates of % cover for woodland/forest, grassland, wetland, and cultivated land were compared with those extracted from historical maps within 3‐km radius around each bog. Map‐extracted land‐use categories and pollen‐based LRA estimates (in % cover) of the same land‐use categories show a reasonable agreement in several cases; when they do not agree, the assumptions used in the data (maps)‐model (LRA) comparison are a better explanation of the discrepancies between the two than possible biases of the LRA modeling approach. Both the LRA reconstructions and the historical maps reveal between‐site differences in landscape characteristics through time, but they demonstrate comparable, profound transformations of the regional and local landscapes over time and space due to the agrarian reforms in southern Sweden during the 18th and 19th centuries. The LRA was found to be the most reasonable approach so far to reconstruct quantitatively past landscape changes from fossil pollen data. The existing landscape diversity in the region at the beginning of the 18th century had its origin in the long‐term regional and local vegetation and land‐use history over millennia. Agrarian reforms since the 18th century resulted in a dramatic loss of landscape diversity and evenness in both time and space over the last two centuries leading to a similarly dramatic loss of species (e.g., beetles).
Long‐term follow‐up results of the Pacing to Avoid Cardiac Enlargement (PACE) trial
Authors: Yu Cheuk‐Man , Fang Fang , Luo Xiu‐Xia , Zhang Qing , Azlan Hussin , Razali Omar 
Published: September 2014

AimsWe report the results of long‐term follow‐up of the Pacing to Avoid Cardiac Enlargement (PACE) trial, a prospective, double‐blinded, randomized, multicentre study that confirmed the superiority of biventricular (BiV) pacing compared with right ventricular apical (RVA) pacing in prevention of LV adverse remodelling and deterioration of systolic function at 1 and 2 years.Methods and resultsPatients with bradycardia and preserved LVEF were randomized to receive RVA (n = 88) or BiV pacing (n = 89). Co‐primary endpoints were LV end‐systolic volume (LVESV) and LVEF measured by echocardiography. There were 149 patients who had extended follow‐up, with a mean duration of 4.8 ± 1.5 years (2.5–7.8 years). The primary endpoint analyses were performed in 146 patients (74 in the RVA group and 72 in the BiV group). In the RVA pacing group, the LVEF decreased while the LVESV increased progressively at follow‐up, but remained unchanged in the BiV pacing group. The differences in LVEF between the RVA and BiV groups were –6.3, –9.2, and –10.7% at 1‐year, 2‐year, and long‐term follow‐up, respectively (all P < 0.001). The corresponding differences in LVESV were +7.4, +9.9, and +13.1 mL, respectively (all P < 0.001). The deleterious effects of RVA pacing consistently occurred in all the pre‐defined subgroups. Furthermore, patients with RVA pacing had a significantly higher prevalence of heart failure hospitalization than the BiV group (23.9% vs. 14.6%, log‐rank χ2 = 7.55, P = 0.006).ConclusionLeft ventricular adverse remodelling and deterioration of systolic function continued at long‐term follow‐up in patients with RVA pacing; this deterioration was prevented by the use of BiV pacing. Also, heart failure hospitalization was more prevalent in the RVA pacing group.Trial registration CUHK_CCT00037.
Synthesis and Characterization of the Nitrophenol Energetic Ionic Salts of 5,6,7,8‐Tetrahydrotetrazolo[1,5‐b][1,2,4]triazine
Authors: Wu Jin‐Ting , Zhang Jian‐Guo , Yin Xin , He Piao , Zhang Tong‐Lai 
Published: September 2014

AbstractNitrophenol energetic ionic salts based on the 5,6,7,8‐tetrahydrotetrazolo[1,5‐b][1,2,4]triazine (TZTN, 1) cation and nitrophenol anions have been synthesized in high yields by neutralization reactions. All the salts were characterized by X‐ray single‐crystal diffraction technology, IR spectroscopy, elemental analysis, and DSC measurements. The heats of formation of 2–4 were calculated by using isodesmic reactions. The calculated detonation pressures of these salts range from 29.7 to 32.6 GPa and their detonation velocities fall between 8337 and 8613 m s–1; these properties make them competitive energetic materials. In addition, the sensitivities towards impact, friction, and flame were tested, and the results indicated that salts 2 and 3 have acceptable sensitivities, whereas salt 4 shows relatively high sensitivity towards impact and flame.
Water Loss Versus Soaking Time: Spontaneous Imbibition in Tight Rocks
Authors: Lan Qing , Ghanbari Ebrahim , Dehghanpour Hassan , Hawkes Robert 
Published: September 2014

AbstractThe combined application of multilateral horizontal drilling and multistage hydraulic fracturing has successfully unlocked unconventional tight hydrocarbon reservoirs. However, the field data show that only a small fraction of the injected water during hydraulic fracturing treatments is recovered during flowback operations. The fate of nonrecovered water and its impact on hydrocarbon production are poorly understood. This paper aims at understanding the relationship between water loss and rock petrophysical properties. It also investigates the correlation between water loss and soaking time (well shut‐in time). Extensive spontaneous imbibition experiments are conducted on downhole samples from the shale members of the Horn River Basin and from the Montney tight gas formation. These samples are characterized by measuring porosity, mineralogy and TOC. Further, a simple methodology is used to scale up the laboratory data for predicting water imbibition volume during the shut‐in period after hydraulic fracturing operations.
Rod-shaped iron oxide nanoparticles are more toxic than sphere-shaped nanoparticles to murine macrophage cells
Authors: Lee Jang Han , Ju Jae Eun , Kim Byung Il , Pak Pyo June , Choi Eun-Kyung , Lee Hoi-Seon , Chung Namhyun 
Published: September 2014

Abstract

Variable sizes of nanoparticles, ranging from nano to micro scale, are of toxicological interest. In the present study, the authors hypothesized that, in addition to the size, the shape of iron oxide (Fe2O3) nanoparticles is a major factor that contributes to particle cytotoxicity. Cytotoxicity to mouse macrophage cells (RAW 264.7) was investigated using 3 different particles: micro-sized Fe2O3 (M-Fe2O3), nano-sized Fe2O3 (N-Fe2O3), and rod-shaped Fe2O3 (R-Fe2O3). Whereas M-Fe2O3 and N-Fe2O3 were located in the vacuole as aggregates, R-Fe2O3 was often spread throughout the cytoplasm. The extent of cytotoxicity measured by the water soluble tetrazolium (WST-1) assay was in the order R-Fe2O3 ≈ N-Fe2O3 &gt; M-Fe2O3, whereas the extent revealed by the lactate dehydrogenase assay was in the order R-Fe2O3 &gt;&gt; N-Fe2O3 ≈ M-Fe2O3. In addition, the degree of tumor necrosis factor–α and reactive oxygen species (ROS) production was in the order of R-Fe2O3 &gt; N-Fe2O3 &gt; M-Fe2O3. In addition, a much higher extent of necrosis was associated with the presence of R-Fe2O3. These results suggest that the higher degree of necrosis due to R-Fe2O3 is correlated with both the higher degree of membrane damage and ROS production by R-Fe2O3 compared with the results of the other Fe2O3 particles. These results also showed that the degree of cytotoxicity of nanoparticles should be evaluated based on shape as well as size, because changes in shape and size are accompanied by alterations in surface area, which relate closely to cytotoxicity. Environ Toxicol Chem 2014;33:2759–2766. © 2014 SETAC