bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous determination of acetylsalicylic acid and salicylic acid in human plasma by isocratic high‐pressure liquid chromatography with post‐column hydrolysis and fluorescence detection
Authors: Hobl Eva‐Luise , Jilma Bernd , Ebner Josef , Schmid Rainer W. 
Published: November 2012

ABSTRACTA selective, sensitive and rapid high‐performance liquid chromatography method with post‐column hydrolysis and fluorescence detection was developed for the simultaneous quantification of acetylsalicylic acid and its metabolite salicylic acid in human plasma. Following the addition of 2‐hydroxy‐3‐methoxybenzoic acid as internal standard and simple protein precipitation with acetonitrile, the analytes were separated on a ProntoSIL 120 C18 ace‐EPS column (150 × 2 mm, 3 µm) protected by a C8 guard column (5 µm). The mobile phase, 10 mm formic acid in water (pH 2.9) and acetonitrile (70:30, v/v), was used at a flow rate of 0.35 mL/min. After on‐line post‐column hydrolysis of acetylsalicylic acid (ASA) to salicylic acid (SA) by addition of alkaline solution, the analytes were measured at 290 nm (λex) and 400 nm (λem). The method was linear in the concentration ranges between 0.05 and 20 ng/μL for both ASA and SA with a lower limit of quantification of 25 pg/μL for SA and 50 pg/μL for ASA. The limit of detection was 15 pg/μL for SA and 32.5 pg/μL for ASA. The analysis of ASA and SA can be carried out within 8 min; therefore this method is suitable for measuring plasma concentrations of salicylates in clinical routine. Copyright © 2012 John Wiley & Sons, Ltd.
Neuroanatomy of the female abdominopelvic region: A review with application to pelvic pain syndromes
Authors: Shoja Mohammadali M. , Sharma Amit , Mirzayan Nadine , Groat Chris , Watanabe Koichi , Loukas Marios , Shane Tubbs R. 
Published: November 2012

AbstractPelvic pain can be a life altering disease. Multiple pathologies can affect this region resulting in neurologic issues. Therefore, a thorough understanding of the nerve supply to this region is important for the clinician who treats such patients. The current review outlines the anatomy of the nervous system of the abdominopelvic region with special attention to this anatomy in the female. Clin. Anat. 26:66–76, 2013. © 2012 Wiley Periodicals, Inc.
Augmentation of ADAMTS9 gene expression by IL‐1β is reversed by NFκB and MAPK inhibitors, but not PI3 kinase inhibitors
Authors: Uysal Sema , Ünal Zahide Nur , Erdoğan Serpil , Akyol Sümeyya , Ramazan Yiğitoğlu M. , Hirohata Satoshi , Işık Bünyamin , Demircan Kadir 
Published: November 2012

The pathways involved in the regulation of a disintegrin and metalloproteinase with thrombospondin motifs 9 (ADAMTS9) expression have not yet been elucidated. Therefore, the aim of this study was to investigate the involvement of nuclear factor‐κB (NF‐κB), mitogen activated protein kinases (MAPK) and Phosphatidylinositol 3‐kinase (PI3 kinase) in ADAMTS9 gene regulation, with special focus on the involvement of NF‐κB in IL‐1β‐induced ADAMTS9 expression. The OUMS‐27 chondrosarcoma cells were exposed to IL‐1β. They were pretreated with 20 μM PD98059 (specific inhibitor of p44/42 kinase), 10 μM SB203580 (specific inhibitor of p38 kinase), 20 μM SB600125 (MAPK inhibitor), and 1 μM Wortmannin and 10 μM LY294002 (specific inhibitors of PI3 kinase) for 30 min and subsequently incubated with IL‐1β. For the effects of NF‐κB and IκB inhibitors, cells were pretreated with curcumin or BAY117085 for 30 min and subsequently incubated with IL‐1β. BAY117085 and different concentrations of curcumin were applied to the cells just after the first experiment to determine their concentration effect on ADAMTS9 gene expression. After total RNA was extracted, they were reversely transcribed with random primers and then real‐time polymerase chain reaction (PCR) was performed on cDNA samples.There was a significant difference between control and stimulated cells in terms of ADAMTS9/β‐actin ratio. Wortmannin and LY294002 did not have any repressive effect on the OUMS‐27 whereas SB203580 and SP600125 were found to decrease the expression of ADAMTS9 gene. BAY 117085 and curcumin, which are two NF‐κB inhibitors, led to a decrease in the ratio of ADAMTS9/β‐actin. As a conclusion, the pathways MAPK and NF‐κB were thought to be responsible pathways for the induction of ADAMTS9 gene. Copyright © 2012 John Wiley & Sons, Ltd.
The Effect of the Fluorine Substitution on the Enantioselective Oxidation of Sulfides with Chiral Titanium Catalysts: A Combined Computational and Experimental Investigation
Authors: Capozzi Maria Annunziata M. , Capitelli Francesco , Bottoni Andrea , Calvaresi Matteo , Cardellicchio Cosimo 
Published: November 2012

AbstractThe results of a combined computational‐experimental study of the oxidation of various fluorinated aryl benzyl sulfides using tert‐butyl hydroperoxide (TBHP) in the presence of a complex of titanium and (S,S)‐hydrobenzoin are presented. As observed in previous studies for other aryl benzyl sulfides, the reaction leads to enantiopure sulfoxides (ee>98 %) in good isolated yields (81–96 %) except the case of pentafluorobenzyl pentafluorophenyl sulfide for which a lower ee (61 %) is observed. DFT computations on a model‐system formed by the substrate, the oxidant TBHP and the [(S,S)‐hydrobenzoin]2‐Ti complex satisfactorily explain this unexpected item. The enantioselectivity is governed by the relative energy of the two diastereomeric octahedral complexes that form if TBHP approaches the initial complex between substrate and [(S,S)‐hydrobenzoin]2‐Ti before the oxygen transfer. For pentafluorobenzyl pentafluorophenyl sulfide, the two octahedral complexes are almost degenerate and, thus, they form in similar amounts. As the two corresponding diastereomeric transition states are similar in energy, the probability to follow one or the other diastereomeric reaction channel becomes comparable, which leads to the lower enantiomeric excess experimentally observed. Our computations indicate that the particular “folded conformation”, adopted by the substrate only if both phenyl rings are fluorinated, is the key factor that determines the near degeneracy of the two diastereomeric octahedral complexes.
Unusual Salt‐Induced Color Modulation through Aggregation‐Induced Emission Switching of a Bis‐cationic Phenylenedivinylene‐Based π Hydrogelator
Authors: Bhattacharya Santanu , Samanta Suman K. 
Published: November 2012

AbstractThe synthesis, hydrogelation, and aggregation‐induced emission switching of the phenylenedivinylene bis‐N‐octyl pyridinium salt is described. Hydrogelation occurs as a consequence of π‐stacking, van der Waals, and electrostatic interactions that lead to a high gel melting temperature and significant mechanical properties at a very low weight percentage of the gelator. A morphology transition from fiber‐to‐coil‐to‐tube was observed depending on the concentration of the gelator. Variation in the added salt type, salt concentrations, or temperature profoundly influenced the order of aggregation of the gelator molecules in aqueous solution. Formation of a novel chromophore assembly in this way leads to an aggregation‐induced switch of the emission colors. The emission color switches from sky blue to white to orange depending upon the extent of aggregation through mere addition of external inorganic salts. Remarkably, the salt effect on the assembly of such cationic phenylenedivinylenes in water follow the behavior predicted from the well‐known Hofmeister effects. Mechanistic insights for these aggregation processes were obtained through the counterion exchange studies. The aggregation‐induced emission switching that leads to a room‐temperature white‐light emission from a single chromophore in a single solvent (water) is highly promising for optoelectronic applications.
Mutual Lewis Acid–Base Interactions of Cations and Anions in Ionic Liquids
Authors: Holzweber Markus , Lungwitz Ralf , Doerfler Denise , Spange Stefan , Koel Mihkel , Hutter Herbert , Linert Wolfgang 
Published: November 2012

AbstractSolute properties are known to be strongly influenced by solvent molecules due to solvation. This is due to mutual interaction as both the properties of the solute and of the solvent strongly depend on each other. The present paper is based on the idea that ionic liquids are cations solvated by anions and anions solvated by cations. To show this (in this system strongly pronounced) interaction the long time established donor–acceptor concept for solvents and ions in solution by Viktor Gutmann is extended to ionic liquids. A number of solvent parameters, such as the Kamlet–Abboud–Taft and the Dimroth–Reichardt ET scale for ionic liquids neglect this mutual influence, which, however, seems to be in fact necessary to get a proper description of ionic liquid properties. It is shown how strong such parameters vary when the influence of the counter ion is taken into account. Furthermore, acceptor and donor numbers for ionic liquids are presented.
FeIII Quinolylsalicylaldimine Complexes: A Rare Mixed‐Spin‐State Complex and Abrupt Spin Crossover
Authors: Harding David J. , Sertphon Darunee , Harding Phimphaka , Murray Keith S. , Moubaraki Boujemaa , Cashion John D. , Adams Harry 
Published: November 2012

AbstractA new synthesis of (8‐quinolyl)‐5‐methoxysalicylaldimine (Hqsal‐5‐OMe) is reported and its crystal structure is presented. Two FeIII complexes, [Fe(qsal‐5‐OMe)2]Cl⋅solvent (solvent=2 MeOH⋅0.5 H2O (1) and MeCN⋅H2O (2)) have been prepared and their structural, electronic and magnetic properties studied. [Fe(qsal‐5‐OMe)2] Cl⋅2 MeOH⋅0.5 H2O (1) exhibits rare crystallographically independent high‐spin and low‐spin FeIII centres at 150 K, whereas [Fe(qsal‐5‐OMe)2]Cl⋅ MeCN⋅H2O (2) is low spin at 100 K. In both structures there are extensive π–π and CH⋅⋅⋅π interactions. SQUID magnetometry of 2 reveals an unusual abrupt stepped‐spin crossover with T1/2=245 K and 275 K for steps 1 and 2, respectively, with a slight hysteresis of 5 K in the first step and a plateau of 15 K between the steps. In contrast, 1 is found to undergo an abrupt half‐spin crossover also with a hysteresis of 10 K. The two compounds are the first FeIII complexes of a substituted qsal ligand to exhibit abrupt spin crossover. These conclusions are supported by 57Fe Mössbauer spectroscopy. Both complexes exhibit reversible reduction to FeII at −0.18 V and irreversible oxidation of the coordinated qsal‐5‐OMe ligand at +1.10 V.
Encapsulating Sulfur into Hierarchically Ordered Porous Carbon as a High‐Performance Cathode for Lithium–Sulfur Batteries
Authors: Ding Bing , Yuan Changzhou , Shen Laifa , Xu Guiyin , Nie Ping , Zhang Xiaogang 
Published: November 2012

AbstractA three‐dimensional (3D) hierarchical carbon–sulfur nanocomposite that is useful as a high‐performance cathode for rechargeable lithium–sulfur batteries is reported. The 3D hierarchically ordered porous carbon (HOPC) with mesoporous walls and interconnected macropores was prepared by in situ self‐assembly of colloidal polymer and silica spheres with sucrose as the carbon source. The obtained porous carbon possesses a large specific surface area and pore volume with narrow mesopore size distribution, and acts as a host and conducting framework to contain highly dispersed elemental sulfur. Electrochemical tests reveal that the HOPC/S nanocomposite with well‐defined nanostructure delivers a high initial specific capacity up to 1193 mAh g−1 and a stable capacity of 884 mAh g−1 after 50 cycles at 0.1 C. In addition, the HOPC/S nanocomposite exhibits high reversible capacity at high rates. The excellent electrochemical performance is attributed exclusively to the beneficial integration of the mesopores for the electrochemical reaction and macropores for ion transport. The mesoporous walls of the HOPC act as solvent‐restricted reactors for the redox reaction of sulfur and aid in suppressing the diffusion of polysulfide species into the electrolyte. The “open” ordered interconnected macropores and windows facilitate transportation of electrolyte and solvated lithium ions during the charge/discharge process. These results show that nanostructured carbon with hierarchical pore distribution could be a promising scaffold for encapsulating sulfur to approach high specific capacity and energy density with long cycling performance.
Tuning the Nature of the Fluorescent State: A Substituted Polycondensed Dye as a Case Study
Authors: Sissa Cristina , Calabrese Valentina , Cavazzini Marco , Grisanti Luca , Terenziani Francesca , Quici Silvio , Painelli Anna 
Published: November 2012

AbstractAn extensive spectroscopic analysis is presented of an elongated polycondensed dye with a donor–acceptor substitution. The charge‐transfer (CT) state, polarized along the long molecular axis, is close in energy to a local excitation (LE) of the polycondensed system, roughly polarized along the short molecular axis, which makes this system particularly suitable to investigate the subtle LE/CT interplay. An essential‐state model is presented that quantitatively reproduces absorption and fluorescence spectra, as well as fluorescence emission and excitation anisotropy spectra collected in solvents of different polarity and viscosity, which sets a sound basis for the understanding of how solvent polarity and solvent relaxation affect the nature of low‐lying excitations. The markedly different fluorescence emission and excitation anisotropy spectra measured in glassy and liquid polar solvents unambiguously demonstrate the major role played by solvent relaxation in the definition of fluorescence properties of the dye.
Origin of the Magnetic Anisotropy in Heptacoordinate NiII and CoII Complexes
Authors: Ruamps Renaud , Batchelor Luke J. , Maurice Rémi , Gogoi Nayanmoni , Jiménez‐Lozano Pablo , Guihéry Nathalie , de Graaf Coen , Barra Anne‐Laure , Sutter Jean‐Pascal , Mallah Talal 
Published: November 2012

AbstractThe nature and magnitude of the magnetic anisotropy of heptacoordinate mononuclear NiII and CoII complexes were investigated by a combination of experiment and ab initio calculations. The zero‐field splitting (ZFS) parameters D of [Ni(H2DAPBH)(H2O)2](NO3)2⋅2 H2O (1) and [Co(H2DAPBH)(H2O)(NO3)](NO3) [2; H2DAPBH=2,6‐diacetylpyridine bis‐ (benzoyl hydrazone)] were determined by means of magnetization measurements and high‐field high‐frequency EPR spectroscopy. The negative D value, and hence an easy axis of magnetization, found for the NiII complex indicates stabilization of the highest MS value of the S=1 ground spin state, while a large and positive D value, and hence an easy plane of magnetization, found for CoII indicates stabilization of the MS=±1/2 sublevels of the S=3/2 spin state. Ab initio calculations were performed to rationalize the magnitude and the sign of D, by elucidating the chemical parameters that govern the magnitude of the anisotropy in these complexes. The negative D value for the NiII complex is due largely to a first excited triplet state that is close in energy to the ground state. This relatively small energy gap between the ground and the first excited state is the result of a small energy difference between the dxy and ${{\rm{d}}_{x^2 - y^2 } }$ orbitals owing to the pseudo‐pentagonal‐bipyramidal symmetry of the complex. For CoII, all of the excited states contribute to a positive D value, which accounts for the large magnitude of the anisotropy for this complex.
Interfacing Click Chemistry with Automated Oligonucleotide Synthesis for the Preparation of Fluorescent DNA Probes Containing Internal Xanthene and Cyanine Dyes
Authors: Astakhova I. Kira , Wengel Jesper 
Published: November 2012

AbstractDouble‐labeled oligonucleotide probes containing fluorophores interacting by energy‐transfer mechanisms are essential for modern bioanalysis, molecular diagnostics, and in vivo imaging techniques. Although bright xanthene and cyanine dyes are gaining increased prominence within these fields, little attention has thus far been paid to probes containing these dyes internally attached, a fact which is mainly due to the quite challenging synthesis of such oligonucleotide probes. Herein, by using 2′‐O‐propargyl uridine phosphoramidite and a series of xanthenes and cyanine azide derivatives, we have for the first time performed solid‐phase copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) click labeling during the automated phosphoramidite oligonucleotide synthesis followed by postsynthetic click reactions in solution. We demonstrate that our novel strategy is rapid and efficient for the preparation of novel oligonucleotide probes containing internally positioned xanthene and cyanine dye pairs and thus represents a significant step forward for the preparation of advanced fluorescent oligonucleotide probes. Furthermore, we demonstrate that the novel xanthene and cyanine labeled probes display unusual and very promising photophysical properties resulting from energy‐transfer interactions between the fluorophores controlled by nucleic acid assembly. Potential benefits of using these novel fluorescent probes within, for example, molecular diagnostics and fluorescence microscopy include: Considerable Stokes shifts (40–110 nm), quenched fluorescence of single‐stranded probes accompanied by up to 7.7‐fold light‐up effect of emission upon target DNA/RNA binding, remarkable sensitivity to single‐nucleotide mismatches, generally high fluorescence brightness values (FB up to 26), and hence low limit of target detection values (LOD down to <5 nM).
Structural and Dynamic Basis of Human Cytochrome P450 7B1: A Survey of Substrate Selectivity and Major Active Site Access Channels
Authors: Cui Ying‐Lu , Zhang Ji‐Long , Zheng Qing‐Chuan , Niu Rui‐Juan , Xu Yu , Zhang Hong‐Xing , Sun Chia‐Chung 
Published: November 2012

AbstractCytochrome P450 (CYP) 7B1 is a steroid cytochrome P450 7α‐hydroxylase that has been linked directly with bile salt synthesis and hereditary spastic paraplegia type 5 (SPG5). The enzyme provides the primary metabolic route for neurosteroids dehydroepiandrosterone (DHEA), cholesterol derivatives 25‐hydroxycholesterol (25‐HOChol), and other steroids such as 5α‐androstane‐3β,17β‐diol (anediol), and 5α‐androstene‐3β,17β‐diol (enediol). A series of investigations including homology modeling, molecular dynamics (MD), and automatic docking, combined with the results of previous experimental site‐directed mutagenesis studies and access channels analysis, have identified the structural features relevant to the substrate selectivity of CYP7B1. The results clearly identify the dominant access channels and critical residues responsible for ligand binding. Both binding free energy analysis and total interaction energy analysis are consistent with the experimental conclusion that 25‐HOChol is the best substrate. According to 20 ns MD simulations, the Phe cluster residues that lie above the active site, particularly Phe489, are proposed to merge the active site with the adjacent channel to the surface and accommodate substrate binding in a reasonable orientation. The investigation of CYP7B1–substrate binding modes provides detailed insights into the poorly understood structural features of human CYP7B1 at the atomic level, and will be valuable information for drug development and protein engineering.
Syntheses of the Hexahydroindene Cores of Indanomycin and Stawamycin by Combinations of Iridium‐Catalyzed Asymmetric Allylic Alkylations and Intramolecular Diels–Alder Reactions
Authors: Gärtner Martin , Satyanarayana Gedu , Förster Sebastian , Helmchen Günter 
Published: November 2012

AbstractShort and concise syntheses of the hexahydroindene cores of the antibiotics indanomycin (X‐14547 A) and stawamycin are presented. Key methods used are an asymmetric iridium‐catalyzed allylic alkylation, a modified Julia olefination, a Suzuki–Miyaura coupling, and an intramolecular Diels–Alder reaction.
Highly Stable Amorphous Calcium Phosphate Porous Nanospheres: Microwave‐Assisted Rapid Synthesis Using ATP as Phosphorus Source and Stabilizer, and Their Application in Anticancer Drug Delivery
Authors: Qi Chao , Zhu Ying‐Jie , Zhao Xin‐Yu , Lu Bing‐Qiang , Tang Qi‐Li , Zhao Jing , Chen Feng 
Published: November 2012

AbstractHighly stable amorphous calcium phosphate (ACP) porous nanospheres with a relatively uniform size and an average pore diameter of about 10 nm have been synthesized by using a microwave‐assisted hydrothermal method with adenosine 5′‐triphosphate disodium salt (ATP) as the phosphorus source and stabilizer. The as‐prepared ACP porous nanospheres have a high stability in the phosphate buffer saline (PBS) solution for more than 150 h without phase transformation to hydroxyapatite, and the morphology and size were essentially not changed. The important role of ATP and effects of experimental conditions on the formation of ACP porous nanospheres were also investigated. The ACP porous nanospheres were characterized by X‐ray powder diffraction (XRD), Fourier‐transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). This method is facile, rapid, surfactant‐free and environmentally friendly. The as‐prepared ACP porous nanospheres are efficient for anticancer drug (docetaxel) loading and release. The ACP porous nanosphere drug‐delivery system with docetaxel shows a high ability to damage tumor cells, thus, is promising for the application in anticancer treatment.
Self‐Assembled Vesicles with Functionalized Membranes
Authors: Gruber Benjamin , König Burkhard 
Published: November 2012

AbstractBiological membranes play a key role for the function of living organisms. Thus, many artificial systems have been designed to mimic natural cell membranes and their functions. A useful concept for the preparation of functional membranes is the embedding of synthetic amphiphiles into vesicular bilayers. The dynamic nature of such noncovalent assemblies allows the rapid and simple development of bio‐inspired responsive nanomaterials, which find applications in molecular recognition, sensing or catalysis. However, the complexity that can be achieved in artificial functionalized membranes is still rather limited and the control of their dynamic properties and the analysis of membrane structures down to the molecular level remain challenging.
Borated Titania, a New Option for the Selective Enrichment of cis‐Diol Biomolecules
Authors: Wang Shao‐Ting , Chen Di , Ding Jun , Yuan Bi‐Feng , Feng Yu‐Qi 
Published: November 2012

AbstractAs low abundance cis‐diol biomolecules are of great significance in biological organisms, preparation of materials for the selective enrichment of such compounds is highly favorable for the development of the related proteomics and metabolomics. To this end, we have prepared monolithic borated titania by a non‐aqueous sol‐gel strategy as a new inorganic affinity material for the specific capture of nucleosides, glycopeptides and glycoproteins. Benefiting from the inorganic framework, this material prevented the hydrophobic interference, which was somewhat inevitable for the mainstream organic‐based boronate affinity materials. The prepared material was carefully characterized by scanning electron microscope (SEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and nitrogen‐sorption experiments to investigate the morphology and elemental composition. The excellent performance of borated titania on enrichment of cis‐diol biomolecules was demonstrated by extracting the glycopeptides from horseradish peroxidase (HRP) digestion, standard glycoproteins, and nucleosides from a human‐urine matrix. This kind of inorganic affinity material offers a new option for selective enrichment or separation of cis‐diol biomolecules.