bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Synthesis of Tryptamine Derivatives via a Direct, One‐Pot Reductive Alkylation of Indoles.
Authors: Righi Marika , Topi Francesca , Bartolucci Silvia , Bedini Annalida , Piersanti Giovanni , Spadoni Gilberto 
Published: November 2012

AbstractThe method can be used to synthesize melatonin (VIII) and luzindole (IIIe), an MT2 melatonin receptor antagonist.
ChemInform Abstract: Docking, Synthesis and Pharmacological Activity of Novel Urea‐Derivatives Designed as p38 MAPK Inhibitors.
Authors: Moreira Lima Lidia , et al. et al. 
Published: November 2012

AbstractThe title inhibitors are designed by bioisosteric replacement of thiophene by a quinoline nucleus, maintaining the urea pharmacophoric group and the ester subunit present in the prototype GK‐00687.
Timing and related artifacts in multidimensional NMR
Authors: Marion Dominique 
Published: November 2012

AbstractThe information content of multidimensional NMR spectra is limited by the presence of several kinds of artifacts that originate from incorrect timing of evolution periods. The objective of this review is to provide tools for successful implementation of published pulse sequences, in which timing and pulse compensations are often implicit. We will analyze the constraints set by the use of Fourier transformation, the spin precession during rectangular or shaped pulses, the Bloch‐Siegert effects due to pulse on other spins and the delay introduced by the filters for the acquisition dimension. A frequency‐dependent phase correction or an incorrect scaling of the first data point leads to baseline offsets or curvature due to the properties of the Fourier transform. Because any r.f. pulse has a finite length, chemical shift is always active during excitation, flip‐back, inversion, and refocusing pulses. Rectangular or selective shaped pulses can be split into three periods: an ideal rotation surrounded by two chemical shift evolution periods, which should be substracted from the adjacent delays to avoid linear phase correction. Bloch‐Siegert effects originate from irradiation at frequencies near those observed in the spectrum and can lead to phase or frequency shifts. They can be minimized by simultaneous irradiation on both sides of the observed spins. In terms of timing, the very end of the pulse sequence the acquisition behaves differently since the data are filtered by either analog or digital means. This additional delay is filter and spectrometer specific and should be tuned to minimize the required phase correction. Combined together, all these adjustments lead to perfectly phased spectra with flat baseline and no peak shifts or distortion. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40A: 326–340, 2012.
Alkali‐Metal Azides Interacting with Metal–Organic Frameworks
Authors: Armata Nerina , Cortese Remedios , Duca Dario , Triolo Roberto 
Published: November 2012

AbstractInteractions between alkali‐metal azides and metal–organic framework (MOF) derivatives, namely, the first and third members of the isoreticular MOF (IRMOF) family, IRMOF‐1 and IRMOF‐3, are studied within the density functional theory (DFT) paradigm. The investigations take into account different models of the selected IRMOFs. The mutual influence between the alkali‐metal azides and the π rings or Zn centers of the involved MOF derivatives are studied by considering the interactions both of the alkali‐metal cations with model aromatic centers and of the alkali‐metal azides with distinct sites of differently sized models of IRMOF‐1 and IRMOF‐3. Several exchange and correlation functionals are employed to calculate the corresponding interaction energies. Remarkably, it is found that, with increasing alkali‐metal atom size, the latter decrease for cations interacting with the π‐ring systems and increase for the azides interacting with the MOF fragments. The opposite behavior is explained by stabilization effects on the azide moieties and determined by the Zn atoms, which constitute the inorganic vertices of the IRMOF species. Larger cations can, in fact, coordinate more efficiently to both the aromatic center and the azide anion, and thus stabilizing bridging arrangements of the azide between one alkali‐metal and two Zn atoms in an η2 coordination mode are more favored.
Mechanistic Studies on the Transformation of Ethanol into Ethene over Fe‐ZSM‐5 Zeolite
Authors: Maihom Thana , Khongpracha Pipat , Sirijaraensre Jakkapan , Limtrakul Jumras 
Published: November 2012

AbstractEthanol, through the utilization of bioethanol as a chemical resource, has received considerable industrial attention as it provides an alternative route to produce more valuable hydrocarbons. Using a density functional theory approach incorporating the M06‐L functional, which includes dispersion interactions, a large 34T nanocluster model of Fe‐ZSM‐5 zeolite in which T is a Si or Al atom is employed to examine both the stepwise and concerted mechanisms of the transformation of ethanol into ethene. For the stepwise mechanism, ethanol dehydration commences from the first hydrogen abstraction of the ethanol OH group to form the ethoxide‐hydroxide intermediate with a low activation energy of 17.7 kcal mol−1. Consequently, the ethoxide‐hydroxide intermediate is decomposed into ethene through hydrogen abstraction from the ethoxide methyl carbon to either the OH group of hydroxide or the oxygen of the ethoxide group with high activation energies of 64.8 and 63.5 kcal mol−1, respectively. For the concerted mechanism, ethanol transformation into the ethene product occurs in a single step without intermediate formation, with an activation energy of 32.9 kcal mol−1.
Combining Spectroscopy and Theory to Evaluate Structural Models of Metalloenzymes: A Case Study on the Soluble [NiFe] Hydrogenase from Ralstonia eutropha
Authors: Horch Marius , Rippers Yvonne , Mroginski Maria A. , Hildebrandt Peter , Zebger Ingo 
Published: November 2012

AbstractHydrogenases catalyse the reversible cleavage of molecular hydrogen into protons and electrons. While most of these enzymes are inhibited under aerobic conditions, some hydrogenases are catalytically active even at ambient oxygen levels. In particular, the soluble [NiFe] hydrogenase from Ralstonia eutropha H16 couples reversible hydrogen cycling to the redox conversion of NAD(H). Its insensitivity towards oxygen has been formerly ascribed to the putative presence of additional cyanide ligands at the active site, which has been, however, discussed controversially. Based on quantum chemical calculations of model compounds, we demonstrate that spectroscopic consequences of the proposed non‐standard set of inorganic ligands are in contradiction to the underlying experimental findings. In this way, the previous model for structure and function of this soluble hydrogenase is disproved on a fundamental level, thereby highlighting the efficiency of computational methods for the evaluation of experimentally derived mechanistic proposals.
Grafting of ω‐Alkyl Ferrocene Radicals to Carbon Surfaces By Means Of Electrocatalysis with Subnanomolar Transition‐Metal (Pd, Pt, or Au) Layers
Authors: Jouikov Viatcheslav , Simonet Jacques 
Published: November 2012

AbstractElectroreduction of ω‐iodoalkyl ferrocenes (Fc‐Cn‐I) was achieved in non‐aqueous media at carbon electrodes covered with extremely small amounts of transition metals (Γ≤10−9 mol cm−2) galvanostatically deposited onto the surface. Upon such a coverage with metals such as palladium, gold, platinum, and rhodium, the cleavage of the CI bond becomes a one‐electron process leading, within the potential range from −1.0 to −1.5 V vs. Ag/AgCl, to the formation of a free alkyl radical. The addition of these radicals onto the carbon surface may occur to a large extent at the graphitized zones (radical attack on C sites) and dense ferrocene layers, attached to the solid support by alkyl linkers, can thus be formed. Other metals such as copper, nickel, and cobalt were successfully used in this process. The residual metal deposits could be eliminated by simple sonication of the resulting carbon interfaces.
Electrochemical Properties of the Poly(3,4‐ethylenedioxythiophene) Doped with Taurine Ligands
Authors: Kupis Justyna , Migdalski Jan , Lewenstam Andrzej 
Published: November 2012

AbstractPoly(3,4‐ethylenedioxythiophene) films doped with Taurine ligands (PEDOT‐Tau films) were deposited from aqueous solution and made sensitive towards Mg2+or Ca2+ions by conditioning in a mixture of 0.5 M Taurine with saturated magnesium or calcium hydroxide. Potentiometric responses towards selected cations as well as potential transient responses were described. The elemental analysis, morphology and topography were studied to elucidate potentiometric behavior of PEDOT‐Tau films. The elemental analysis was made for freshly deposited and sensitized for magnesium and calcium films by using X‐ray Photoelectron Spectroscopy (XPS), Energy Dispersive Analysis of X‐ray (EDAX) and Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA‐ICP‐MS). The morphology and topography of such films were inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM).
Toward Universal Design in Public Transportation Systems: An Analysis of Low‐Floor Bus Passenger Behavior with Video Observations
Authors: Hwangbo Hwan , Kim Jiyeon , Kim Sunwoong , Ji Yong Gu 
Published: November 2012

AbstractThis study aims to investigate the relationship between ergonomic comfort and the provision of accessibility features for mobility‐impaired persons in the use of public transportation systems in Korea. To deal with mobility issues in a public transportation environment, we chose the low‐floor bus as our research subject because it is the representative of a barrier‐free design solution. We collected data via video observation, which can overcome the limitations of traditional accessibility‐focused studies and laboratory studies by providing data on real usage patterns. We developed a framework to analyze the gathered data which includes user, space, tools, activities, and context. As a result, we observed existing difficulties of mobility‐impaired persons in terms of moving and supporting their bodies on the bus, despite the application of accessibility features. Furthermore, the design only for accessibility of mobility‐disabled persons can cause unexpected predicaments for the passengers who do not have physical handicaps. Drawing on these findings, we concluded that the concept of universal design in public transportation environments must be introduced in Korea. This study suggests video observation as a useful methodology for collecting data in dynamic environments. Additionally, our study is expected to contribute to how the concept of universal design can be implemented, and stimulate issues for ergonomic research based on our behavior pattern analysis.
Perfluorinated Bis(dihydrooxazole) Complexes Immobilized on Fluorous Reversed‐Phase Silica Gel as Recyclable Catalysts for Enantioselective DielsAlder Reactions
Authors: Hensle Eva M. , Bannwarth Willi 
Published: November 2012

AbstractThe three different perfluoroalkyl‐tagged bis(dihydrooxazole)copper complexes 19–21 were synthesized and immobilized noncovalently on fluorous reversed‐phase silica gel (FRPSG) by fluorousfluorous interactions (Schemes 2 and 3). These supported catalysts were successfully applied to asymmetric DielsAlder reactions in H2O and in CH2Cl2 (Scheme 4). Besides high conversion of the dienophile, we observed enantiomer excesses of up to 88% in H2O and 97% in CH2Cl2, and we were able to recover and re‐use these catalytic systems several times. Despite the relatively high catalyst loading, the leaching of copper was remarkably low ranging from 2.4 to 5.9 ppm.
The critical role of mast cell‐derived hypoxia‐inducible factor‐1α in human and mice melanoma growth
Authors: Jeong Hyun‐Ja , Oh Hyun‐A , Nam Sun‐Young , Han Na‐Ra , Kim Young‐Sick , Kim Jeong‐Hwa , Lee Seok‐Jong , Kim Min‐Ho , Moon Phil‐Dong , Kim Hyung‐Min , Oh Hyun‐A 
Published: November 2012

AbstractMast cells play an important role in tumorigenesis. Histamine released from mast cells stimulates new vessel formation by acting through the histamine1 (H1) receptor. Despite the evidence of the role of mast cells in tumor growth and angiogenesis, the potential mechanism remains to be elucidated. Therefore, we investigated the role of mast cell‐derived HIF‐1α in melanoma growth. Here, we identify that the most positive cells for HIF‐1α staining are seen in mast cells of human and animal melanoma tissue. The number of the stromal cell types (fibroblasts, macrophages and endothelial cells) was also increased in melanoma tissues. In activated bone marrow‐derived mast cells (BMMCs), expressions of HIF‐1α and VEGF were increased. Histamine also induced the expressions of HIF‐1α and VEGF in BMMCs. H1 receptor antagonists significantly improved overall survival rates and substantially suppressed tumor growth as well as the infiltration of mast cells and levels of VEGF through the inhibition of HIF‐1α expression in B16F10 melanoma‐bearing mice. Furthermore, the injection of HIF‐1α depleted BMMCs markedly inhibited the growth of tumors and migration of mast cells and increased the survival rate of the mice. These findings emphasize that the growth of melanoma can actually be exacerbated by mast cell‐derived HIF‐1α. In aggregate, our results reveal a novel role for mast cell‐derived HIF‐1α in the melanoma microenvironment and have important implications for the design of therapeutic strategies.
Tricyclic antidepressant use and risk of fractures: A meta-analysis of cohort and case-control studies
Authors: Wu Qing , Qu Wenchun , Crowell Michael D , Hentz Joseph G , Frey Keith A 
Published: November 2012

Abstract
Because studies of the association between tricyclic antidepressant (TCA) treatment and risk of fracture have shown inconsistent findings, we sought to assess whether people who take TCAs are at increased risk of fracture. Relevant studies published by June 2012 were identified through database searches of Scopus, MEDLINE, EMBASE, PsycINFO, ISI Web of Science, and WorldCat Dissertations and Theses from their inception, and manual searching of reference lists. Only original studies that examined the association between TCA treatment and risk of fracture were included. Two investigators independently conducted literature searches, study selection, study appraisal, and data abstraction using a standardized protocol. Disagreements were resolved by consensus. Twelve studies met inclusion criteria. Because of the heterogeneity of these studies, random-effects models were used to pool estimates of effect. Overall, TCA use was associated with significantly increased fracture risk (relative risk [RR], 1.45; 95% confidence interval [CI], 1.31–1.60; p &lt; 0.001). Increased fracture risk associated with TCA use was also observed in studies that adjusted for bone mineral density (RR, 1.54; 95% CI, 1.24–1.90; p &lt; 0.001) or depression (RR, 1.49; 95% CI, 1.28–1.67; p &lt; 0.001). Strength of association with TCA exposure duration ≥6 weeks (RR, 1.13; 95% CI, 1.00–1.28) was substantially weaker than association with TCA exposure duration &lt;6 weeks (RR, 2.40; 95% CI, 1.41–4.08). Prior TCA exposure had no significant effect on fracture risk (RR, 1.04; 95% CI, 0.86–1.26; p = 0.70). After accounting for publication bias, we found the overall association between TCA use and fracture risk to be slightly weaker (RR, 1.36; 95% CI, 1.24–1.50) but still significant (p &lt; 0.001). Findings of this meta-analysis indicate that treatment with TCAs may convey an increased risk of fracture, independent of depression and bone mineral density. © 2013 American Society for Bone and Mineral Research.
Partial reductions in mechanical loading yield proportional changes in bone density, bone architecture, and muscle mass
Authors: Ellman Rachel , Spatz Jordan , Cloutier Alison , Palme Rupert , Christiansen Blaine A , Bouxsein Mary L 
Published: November 2012

Abstract
Although the musculoskeletal system is known to be sensitive to changes in its mechanical environment, the relationship between functional adaptation and below-normal mechanical stimuli is not well defined. We investigated bone and muscle adaptation to a range of reduced loading using the partial weight suspension (PWS) system, in which a two-point harness is used to offload a tunable amount of body weight while maintaining quadrupedal locomotion. Skeletally mature female C57Bl/6 mice were exposed to partial weight bearing at 20%, 40%, 70%, or 100% of body weight for 21 days. A hindlimb unloaded (HLU) group was included for comparison in addition to age-matched controls in normal housing. Gait kinematics was measured across the full range of weight bearing, and some minor alterations in gait from PWS were identified. With PWS, bone and muscle changes were generally proportional to the degree of unloading. Specifically, total body and hindlimb bone mineral density, calf muscle mass, trabecular bone volume of the distal femur, and cortical area of the femur midshaft were all linearly related to the degree of unloading. Even a load reduction to 70% of normal weight bearing was associated with significant bone deterioration and muscle atrophy. Weight bearing at 20% did not lead to better bone outcomes than HLU despite less muscle atrophy and presumably greater mechanical stimulus, requiring further investigation. These data confirm that the PWS model is highly effective in applying controllable, reduced, long-term loading that produces predictable, discrete adaptive changes in muscle and bone of the hindlimb. © 2012 American Society for Bone and Mineral Research © 2013 American Society for Bone and Mineral Research
Identification, characterization, and isolation of a common progenitor for osteoclasts, macrophages, and dendritic cells from murine bone marrow and periphery
Authors: Jacome-Galarza Christian E , Lee Sun-Kyeong , Lorenzo Joseph A , Aguila Hector Leonardo 
Published: November 2012

Abstract
Osteoclasts are specialized bone-resorbing cells that derive from monocyte precursors. We have identified three populations of cells with high osteoclastogenic potential in murine bone marrow, which expressed the phenotype B220-CD3-CD11b−/low CD115+ and either CD117hi, CD117intermediate, or CD117low. We have evaluated these populations for their ability to also generate macrophages and dendritic cells. At a single-cell level, the population expressing higher CD117 levels was able to generate bone-resorbing osteoclasts, phagocytic macrophages, and antigen-presenting dendritic cells in vitro with efficiencies of more than 90%, indicating that there exists a common developmental pathway for these cell types. Cells with osteoclastogenic potential also exist in blood and peripheral hematopoietic organs. Their functional meaning and/or their relationship with bone marrow progenitors is not well established. Hence, we characterized murine peripheral cell populations for their ability to form osteoclasts, macrophages, and dendritic cells in vitro. The spleen and peripheral blood monocyte progenitors share phenotypic markers with bone marrow progenitors but differ in their expression of CD11b, which was low in bone marrow but high in periphery. We propose that circulating monocyte progenitors are derived from a common bone marrow osteoclasts/macrophage/dendritic cell progenitor (OcMDC), which we have now characterized at a clonal level. However, the lineage relationship between the bone marrow and peripheral monocyte progenitors has yet to be defined. © 2013 American Society for Bone and Mineral Research.
Brain perfusion imaging: How does it work and what should I use?
Authors: McGehee Blake E. , Pollock Jeffrey M. , Maldjian Joseph A. 
Published: November 2012

AbstractIn the last 15 years there has been a relative explosion in the number of magnetic resonance imaging (MRI) techniques and developments related to cerebral perfusion. Given the variety of perfusion methods available, it is often difficult to decide which technique would be best for a particular clinical question or patient. In this review article we discuss the more common techniques, review how they are performed, and summarize the optimal technique or techniques for a variety of clinical situations. J. Magn. Reson. Imaging 2012; 36:1257–1272. © 2012 Wiley Periodicals, Inc.
Biocompatible Multishell Architecture for Iron Oxide Nanoparticles
Authors: Wotschadlo Jana , Liebert Tim , Clement Joachim H. , Anspach Nils , Höppener Stephanie , Rudolph Tobias , Müller Robert , Schacher Felix H. , Schubert Ulrich S. , Heinze Thomas 
Published: November 2012

AbstractThe coating of super‐paramagnetic iron oxide nanoparticles (SPIONs) with multiple shells is demonstrated by building a layer assembled from carboxymethyldextran and poly(diallydimethylammonium chloride). Three shells are produced stepwise around aggregates of SPIONs by the formation of a polyelectrolyte complex. A growing particle size from 96 to 327 nm and a zeta potential in the range of +39 to −51 mV are measured. Microscopic techniques such as TEM, SEM, and AFM exemplify the core‐shell structures. Magnetic force microscopy and vibrating sample magnetometer measurements confirm the architecture of the multishell particles. Cell culture experiments show that even nanoparticles with three shells are still taken up by cells. magnified image
Localization errors in MR spectroscopic imaging due to the drift of the main magnetic field and their correction
Authors: Tal Assaf , Gonen Oded 
Published: November 2012

Purpose: To analyze the effect of B0 field drift on multivoxel MR spectroscopic imaging and to propose an approach for its correction.Theory and Methods: It is shown, both theoretically and in a phantom, that for ∼30 min acquisitions a linear B0 drift (∼0.1 ppm/h) will cause localization errors that can reach several voxels (centimeters) in the slower varying phase encoding directions. An efficient and unbiased estimator is proposed for tracking the drift by interleaving short (∼
), nonlocalized acquisitions on the nonsuppressed water each pulse repetition time, as shown in 10 volunteers at 1.5 and 3 T.Results: The drift is shown to be predominantly linear in both the phantom and volunteers at both fields. The localization errors are observed and quantified in both phantom and volunteers. The unbiased estimator is shown to reliably track the instantaneous frequency in vivo despite only using a small portion of the FID.Conclusion: Contrary to single‐voxel MR spectroscopy, where it leads to line broadening, field drift can lead to localization errors in the longer chemical shift imaging experiments. Fortunately, this drift can be obtained at a negligible cost to sequence timing, and corrected for in post processing. Magn Reson Med, 70:895–904, 2013. © 2012 Wiley Periodicals, Inc.