bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic review of phaeochromocytoma in pregnancy
Authors: Biggar M A , Lennard T W J
Published: November 2012

Background

Phaeochromocytoma in pregnancy is a rare and potentially dangerous situation for mother and fetus. This review aimed to assess current mortality rates and how medical and surgical management affect these.

Methods

Articles in English published between 2000 and 2011 were obtained from a MEDLINE search. Eligible publications presented women diagnosed with phaeochromocytoma in the antenatal or immediate postnatal period, and reported management and outcomes.

Results

A total of 135 reports were identified. After applying inclusion criteria, 77 pregnancies involving 78 fetuses were analysed. Fetal and maternal mortality rates were 17 per cent (13 of 78) and 8 per cent (6 of 77) respectively. Better outcomes were achieved when the diagnosis of phaeochromocytoma was made in the antenatal period than when it was made during labour or immediately postpartum (survival of both mother and fetus(es) in 48 of 56 versus 12 of 21 respectively; P = 0·012). When the diagnosis was made before 23 weeks' gestation, there was no difference in outcomes when phaeochromocytoma surgery was carried out in the second trimester, compared with when it was postponed to the third trimester or after delivery (fetal death 2 of 18 versus 2 of 8 respectively; P = 0·563).

Conclusion

This review, although limited by the rarity of the condition and level of available evidence, demonstrated that survival rates are improved if the diagnosis of phaeochromocytoma can be established antenatally. With diagnosis before 23 weeks' gestation, no definite advantage of proceeding with tumour removal during the second trimester could be demonstrated.
The problem of the poor control arm in surgical randomized controlled trials
Authors: Strobel O , Büchler M W
Published: November 2012

Greater attention needed to achieve equipoise in surgical trials
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

A 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

Pelvic 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

The 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

The 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

Solute 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

A 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

A 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

An 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

The 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

Double‐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

Cytochrome 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

Short 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

Highly 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

Biological 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

As 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.
Preparation of a Hyper‐cross‐linked Polymer Monolithic Column and Its Application to the Sensitive Determination of Genomic DNA Methylation
Authors: Chen Ming‐Luan , Liu Yu‐Li , Xing Xi‐Wen , Zhou Xiang , Feng Yu‐Qi , Yuan Bi‐Feng
Published: November 2012

A hyper‐cross‐linked polymer monolithic column, poly(methacrylatoethyl trimethyl ammonium‐co‐vinylbenzene chloride‐co‐divinylbenzene) (MATE‐co‐VBC‐co‐DVB) with phenyl and quaternary ammonium groups was successfully prepared in the current study. The prepared monolith possesses large specific surface area, narrow mesopore size distribution and high column efficiency. The poly(MATE‐co‐VBC‐co‐DVB) monolithic column was demonstrated to have strong anion exchange/reversed‐phase (SAX/RP) mixed‐mode retention for analytes on capillary liquid chromatography (cLC). By using this monolithic column, we developed a rapid and sensitive method for the detection of DNA methylation. Our results showed that six nucleobases (adenine, guanine, cytosine, thymine, uracil, and 5‐methylcytosine (5‐mC)) can be baseline separated within 15 min by electrostatic repulsion and hydrophobic interactions between nucleobases and the monolithic stationary phase. The limit of detection (LOD, signal/noise=3) of 5‐mC is 0.014 pmol and endogenous 5‐mC can be distinctly detected by using only 10 ng genomic DNA, which is comparable to that obtained by mass spectrometry analysis. Furthermore, by using the method developed here, we found that DNA methylation inhibitor 5‐azacytidine (5‐aza‐C) and 5‐aza‐2′‐deoxycytidine (5‐aza‐CdR) could induce a significant decrease of genome‐wide DNA methylation in human lung carcinoma cells (A549) and cervical carcinoma cells (HeLa).
Template Syntheses of Copper(II) Complexes from Arylhydrazones of Malononitrile and their Catalytic Activity towards Alcohol Oxidations and the Nitroaldol Reaction: Hydrogen Bond‐Assisted Ligand Liberation and E/Z Isomerisation
Authors: Kopylovich Maximilian N. , Mizar Archana , Guedes da Silva M. Fátima C. , Mac Leod Tatiana C. O. , Mahmudov Kamran T. , Pombeiro Armando J. L.
Published: November 2012

A one‐pot template condensation of 2‐(2‐(dicyanomethylene)hydrazinyl)benzenesulfonic acid (H2L1, 1) or 2‐(2‐(dicyanomethylene)hydrazinyl)benzoic acid (H2L2, 2) with methanol (a), ethylenediamine (b), ethanol (c) or water (d) on copper(II), led to a variety of metal complexes, that is, mononuclear [Cu(H2O)2(κO1,κN2 L1a] (3) and [Cu(H2O)(κO1,κN3 L1b)] (4), tetranuclear [Cu4(1 κO1,κN2:2 κO1 L2a)3‐(1 κO1, κN2:2 κO2 L2a)] (5), [Cu2(H2O)(1 κO1, κN2:2 κO1 L2c)‐(1 κO1,1 κN2:2 κO1,2 κN1‐ L2c)]2 (6) and [Cu2(H2O)2(κO1,κN2‐ L1dd)‐(1 κO1,κN2:2 κO1 L1dd)(μ‐H2O)]2⋅ 2 H2O (7⋅2 H2O), as well as polymer‐ ic [Cu(H2O)(κO1,1 κN2:2 κN1 L1c)]n (8) and [Cu(NH2C2H5)(κO1,1 κN2:2 κN1L2a)]n (9). The ligands 2‐SO3H‐C6H4‐(NH)NC{(CN)[C(NH2)‐(NCH2CH2NH2)]} (H2L1b, 10), 2‐CO2H‐C6H4‐(NH)N{C(CN)[C(OCH3)‐(NH)]} (H2L2a, 11) and 2‐SO3H‐C6H4‐(NH)NC{C(O)‐(NH2)}2 (H2L1dd, 12) were easily liberated upon respective treatment of 4, 5 and 7 with HCl, whereas the formation of cyclic zwitterionic amidine 2‐(SO3−)C6H4NNC(C(NH+)CH2CH2NH)(CNHCH2CH2NH) (13) was observed when 1 was treated with ethylenediamine. The hydrogen bond‐induced E/Z isomerization of the (HL1d)− ligand occurs upon conversion of [{Na(H2O)2(μ‐H2O)2}(HL1d)]n (14) to [Cu(H2O)6][HL1d]2⋅2 H2O (15) and [{CuNa(H2O)‐(κN1,1 κO2:2 κO1 L1d)2}K0.5(μ‐O)2]n⋅H2O (16). The synthesized complexes 3–9 are catalyst precursors for both the selective oxidation of primary and secondary alcohols (to the corresponding carbonyl compounds) and the following diastereoselective nitroaldol (Henry) reaction, with typical yields of 80–99 %.
Structure Sensitivity of CO Oxidation on Co3O4: A DFT Study
Authors: Pang Xian‐Yong , Liu Chang , Li Dui‐Chun , Lv Cun‐Qin , Wang Gui‐Chang
Published: November 2012

The reaction mechanism of CO oxidation on the Co3O4 (110) and Co3O4 (111) surfaces is investigated by means of spin‐polarized density functional theory (DFT) within the GGA+U framework. Adsorption situation and complete reaction cycles for CO oxidation are clarified. The results indicate that 1) the U value can affect the calculated energetic result significantly, not only the absolute adsorption energy but also the trend in adsorption energy; 2) CO can directly react with surface lattice oxygen atoms (O2f/O3f) to form CO2 via the Mars–van Krevelen reaction mechanism on both (110)‐B and (111)‐B; 3) pre‐adsorbed molecular O2 can enhance CO oxidation through the channel in which it directly reacts with molecular CO to form CO2 [O2(a)+CO(g)→CO2(g)+O(a)] on (110)‐A/(111)‐A; 4) CO oxidation is a structure‐sensitive reaction, and the activation energy of CO oxidation follows the order of Co3O4 (111)‐A(0.78 eV)>Co3O4 (111)‐B (0.68 eV)>Co3O4 (110)‐A (0.51 eV)>Co3O4 (110)‐B (0.41 eV), that is, the (110) surface shows higher reactivity for CO oxidation than the (111) surface; 5) in addition to the O2f, it was also found that Co3+ is more active than Co2+, so both O2f and Co3+ control the catalytic activity of CO oxidation on Co3O4, as opposed to a previous DFT study which concluded that either Co3+ or O2f is the active site.
Nanoporous PdTi Alloys as Non‐Platinum Oxygen‐Reduction Reaction Electrocatalysts with Enhanced Activity and Durability
Authors: Liu Yunqing , Xu Caixia
Published: November 2012

A nanoporous PdTi (NP‐PdTi) alloy with uniform ligament size and controllable bimetallic ratio was easily fabricated by a one‐step mild dealloying process of PdTiAl (precursor alloy). NP‐PdTi consisted of an interconnected network of nanoscale ligaments with bicontinuous hollow channels extending in all three dimensions. Electrocatalytic measurements indicated that NP‐PdTi had superior electrocatalytic activity in the oxygen reduction reaction (ORR) with enhanced specific and mass activities as well higher methanol tolerance relative to Pt/C. Interestingly, NP‐PdTi showed higher catalytic durability than Pt/C with a lower decrease in the ORR activity and electrochemical surface area of the metal upon 5000 potential cycles in an acidic solution. DFT calculations demonstrated that alloying Pd with Ti could bring favorable electronic perturbation with the downshifted d‐band center of Pd, leading to a weakened PdO bond and improved ORR performance. The excellent electrocatalytic performance in ORR renders NP‐PdTi alloys attractive as efficient cathode electrocatalysts in fuel‐cell‐related technologies.
Gene expression profiling revealed specific spermatogonial stem cell genes in mouse
Authors: Yang Lele , Wu Wei , Qi Huayu
Published: November 2012

Mammalian spermatogenesis originates from spermatogonial stem cells (SSCs), which undergo mitosis, meiosis and spermiogenesis in order to generate mature spermatozoa. SSCs are adult stem cells that can both self‐renew and differentiate. To maintain pluripotency, SSCs are regulated by both extrinsic factors secreted from surrounding somatic cells and intrinsic factors including specific gene expression programs. Using fluorescent labeled germ line stem cells, mouse gonocytes and SSCs were purified up to 97% by improved FACS method. Through microarray analyses, global gene expression profiles of gonocytes, SSCs, and differentiated cells were compared. A large number of distinctive genes were found to be enriched in respective cell populations, indicating different functional requirements of each cell type. Functional clustering analyses revealed that while gonocytes and SSCs preferentially express genes implicated in gene expression regulation and epigenetic modifications, differentiated cells including somatic cells are enriched with genes encoding proteins involved in various cellular activities. Further in situ hybridization and RT‐PCR experiments confirmed SSC specific expression of several genes of which functions have not been characterized in SSCs. The comparative gene expression profiling provides a useful resource for gene discovery in relation to SSC regulation and opens new avenues for the study of molecular mechanisms underlying SSC self‐renewal and differentiation. genesis 51:83–96, 2013. © 2012 Wiley Periodicals, Inc.
Optimization of dry‐season sap flow measurements in an oak semi‐arid open woodland in Spain
Authors: Reyes‐Acosta J. Leonardo , Lubczynski Maciek W.
Published: November 2012

In sap flow studies, there is no method complying with high efficiency and versatility of sap flow measurements. To improve that, we propose combining two methods: (1) thermal dissipation probe (TDP) known to be efficient and cost effective and (2) heat field deformation (HFD) known to be versatile. For that purpose, we used a step‐wise TDP sap flux density (Jp) optimization method consisting of (1) natural temperature gradient (NTG) correction applying the cyclic heat dissipation (CHD) method, (2) night flow ΔTmax correction using HFD data as reference and (3) radial‐azimuthal correction using HFD as reference. We applied this optimization method on Quercus ilex (Q.i.) and Quercus pyrenaica (Q.p.) trees in a Spanish semi‐arid open woodland during dry season. The NTG correction resulted in substantial reduction of Jp as compared with standard TDP. The subsequent ΔTmax night flow correction resulted in the increase of NTG‐corrected Jp and good agreement with the outermost 2 cm of HFD measurements for both species. The final radial‐azimuthal adjustment of TDP Jp resulted not only, in a good agreement with HFD Jp, but also provided novel ecohydrological insights such as: (1) evidence of continuous night flow in all Q.p. trees and some Q.i. trees, (2) exponential reduction of Jp with sapwood depth for both species, (3) significantly larger Jp in the outermost 1 cm of sapwood for Q.p. than for Q.i. and (4) high azimuthal Jp variability for both species. The presented study offers efficient and versatile method of tree sap flow measurements that contributed to a better understanding of water‐related dynamics of Q.i. and Q.p. under water‐stress conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Myeloid leukemia cells with a B7‐2+ subpopulation provoke Th‐cell responses and become immuno‐suppressive through the modulation of B7 ligands
Authors: Dolen Yusuf , Esendagli Gunes
Published: November 2012

Expression of the B7 family molecules in acute myeloid leukemia (AML) has been demonstrated by independent clinical studies. Intriguingly, the expression of the most potent costimulatory molecules B7‐2 (CD86) and B7‐H2 (ICOS Ligand) on AML cells has been associated with poor prognosis and disease severity. Here, this phenomenon was modeled in vitro with the myeloid leukemia cell line HL‐60, which is capable of differentiating through the FAB M2/M3 and M4/M5 immunophenotypes. These derivatives of HL‐60 harbored a B7‐2+ subpopulation and recapitulated the distribution of B7 ligands previously reported in primary AML cases. B7‐2+ AML cells significantly contributed to T‐cell responses. This costimulatory activity enabled helper (Th)‐cell activation, proliferation, and production of Th1‐associated cytokines. Conversely, even a short‐term incubation with stimulated T cells resulted in upregulation of inhibitory B7‐H1 (PD‐L1) and B7‐DC (PD‐L2), and downregulation of stimulatory B7‐H2 molecules on leukemia cells. Purified from iHL‐60‐T‐cell co‐cultures, these myeloid leukemia cells severely suppressed Th‐cell responses specifically through the PD‐1 pathway. In conclusion, Th‐cell responses can be directly supported by B7‐2+ leukemia subpopulations. However, this interaction can facilitate the acquisition of a suppressive character that may contribute to immune evasion in myeloid leukemia.
Application of short‐end injection procedure in CE
Authors: Glatz Zdeněk
Published: November 2012

CE is well known for its many advantages, including the speed of the analyses; most of which can be accomplished in less than 10 min. However many potential fields of application such as pharmaceutical research and industry and clinical diagnostics require analyses of large numbers of samples and so need an even shorter analysis time to be practical. There are generally three main options for enhancing the throughput of electromigration methods – using microchip or multi‐capillary systems or modifying the method preformed on single capillary instruments. The latter option will probably be the method of choice for most laboratories, since they are only equipped with classical commercial CE instrumentation. Although several approaches can be used – higher electric field, EOF modification, external pressure application during analysis, this article reviews one of the simplest and at the same time most used, the so‐called short‐end injection procedure.
Switching between MIMO‐TDMA and MIMO‐CDMA
Authors: Wang Jui Teng
Published: November 2012

The throughput analyses for MIMO‐TDMA (multiple‐input multiple‐output with time division multiple access) and MIMO‐CDMA (multiple‐input multiple‐output with code division multiple access) are performed. These analyses show that there is a crossover in the throughput for MIMO‐TDMA and MIMO‐CDMA. Also, they show that the signal‐to‐noise ratio (SNR) and the number of co‐channel users under multiple access control can determine that either MIMO‐TDMA or MIMO‐CDMA has the advantage in the throughput. We solve one equation that equalizes the upper bounds of throughput and use its solution as the threshold of SNR for the threshold‐based switching algorithm, which switches to MIMO‐TDMA if the received SNR is larger than the threshold of SNR and switches to MIMO‐CDMA otherwise. Simulation results show that the threshold of SNR approximates the crossover SNR (for which MIMO‐TDMA and MIMO‐CDMA have the same throughput) so that the threshold‐based switching scheme (which adopts the threshold based switching algorithm) can switch to the scheme (MIMO‐TDMA or MIMO‐CDMA) that has the largest throughput. Copyright © 2012 John Wiley & Sons, Ltd.
Rugose corals from the Upper Ordovician Sholeshook Limestone of southwest Wales with an assessment of the coral affinities and biofacies
Authors: Baars C.
Published: November 2012

Limestone horizons of Upper Ordovician (Katian) age in southwest Wales contain diverse fossil faunas including rugose corals. The existence of Ordovician Rugosa in Wales was first reported by Murchison in the 1830s, but since then hardly any specimens have been documented systematically until this present study. Newly collected material from the area around Llanddowror (Carmarthenshire) has now confirmed the diversity of rugose corals in the Sholeshook Limestone (Katian age), an arenaceous limestone originating from the shelf edge of the palaeocontinent Avalonia. The majority of the specimens are preserved as moulds. This means that in many instances preservation of the fossils was insufficient for specific identification; nevertheless, it was possible to document a diverse rugose coral fauna, including Helicelasma, probable Grewingkia and Kenophyllum, and a potential early mucophyllid. While associated with considerable difficulties, as some diagnostic features of Rugosa are not visible in moulds, it is demonstrated here that the work with such specimens can result in faunal information which would otherwise be unobtainable. An assemblage of rugose and tabulate corals in the Sholeshook Limestone can be differentiated from a similar assemblage in the neighbouring Robeston Wathen Limestone which has a slightly different lithology. The fauna has strong similarities with other Avalonian (Irish, English, Belgian) as well as Baltic (Estonian and Norwegian) rugose coral faunas. Copyright © 2012 John Wiley & Sons, Ltd.
Placental stem cell correction of murine intermediate maple syrup urine disease
Authors: Skvorak Kristen J. , Dorko Kenneth , Marongiu Fabio , Tahan Veysel , Hansel Marc C. , Gramignoli Roberto , Gibson Michael K. , Strom Stephen C.
Published: November 2012

There is improved survival and partial metabolic correction of a mouse intermediate maple syrup urine disease (iMSUD) model after allogenic hepatocyte transplantation, confirming that a small number of enzyme-proficient liver-engrafted cells can improve phenotype. However, clinical shortages of suitable livers for hepatocyte isolation indicate a need for alternative cell sources. Human amnion epithelial cells (hAECs) share stem cell characteristics without the latter's safety and ethical concerns and differentiate to hepatocyte-like cells. Eight direct hepatic hAEC transplantations were performed in iMSUD mice over the first 35 days beginning at birth; animals were provided a normal protein diet and sacrificed at 35 and 100 days. Treatment at the neonatal stage is clinically relevant for MSUD and may offer a donor cell engraftment advantage. Survival was significantly extended and body weight was normalized in iMSUD mice receiving hAEC transplantations compared with untreated iMSUD mice, which were severely cachectic and died ≤28 days after birth. Branched chain α-keto acid dehydrogenase enzyme activity was significantly increased in transplanted livers. The branched chain amino acids leucine, isoleucine, valine, and alloisoleucine were significantly improved in serum and brain, as were other large neutral amino acids.

Conclusion
: Placental-derived stem cell transplantation lengthened survival and corrected many amino acid imbalances in a mouse model of iMSUD. This highlights the potential for their use as a viable alternative clinical therapy for MSUD and other liver-based metabolic diseases. (Hepatology 2013)
Circulating stem cell–like epithelial cell adhesion molecule–positive tumor cells indicate poor prognosis of hepatocellular carcinoma after curative resection
Authors: Sun Yun-Fan , Xu Yang , Yang Xin-Rong , Guo Wei , Zhang Xin , Qiu Shuang-Jian , Shi Ruo-Yu , Hu Bo , Zhou Jian , Fan Jia
Published: November 2012

Epithelial cell adhesion molecule–positive (EpCAM+) hepatocellular carcinoma (HCC) cells may constitute a tumor-initiating subpopulation in tumorigenic cell lines and HCC specimens. In the present study, EpCAM+ circulating tumor cells (CTCs) were identified prospectively in HCC patients undergoing curative resection, and the prognostic significance and their stem cell–like characteristics were investigated further. Blood samples from 123 HCC patients were tested prior to resection and 1 month thereafter. CTCs were present in 66.67% of patients, and the cell count measured in 7.5 mL of blood (CTC7.5) ranged between 1 and 34. Fifty-one patients had CTC7.5 of ≥2 preoperatively, and these patients developed tumor recurrence earlier than those with CTC7.5 of <2 CTCs (

P

< 0.001). A preoperative CTC7.5 of ≥2 was an independent prognostic factor for tumor recurrence (

P

< 0.001). Its prognostic significance also applied to patients with alpha-fetoprotein (AFP) levels of ≤400 ng/mL or subgroups with low recurrence risk (all

P

< 0.05). A significant decrease of CTC-positive rates (66.67% to 28.15%,

P

< 0.05) and CTC7.5 values (2.60 ± 0.43 to 1.00 ± 0.36,

P

< 0.05) was observed 1 month after resection. Patients with consistent CTC7.5 <2 had lower recurrence rates than those with values consistently ≥2 (15.5% versus 87.50%,

P

< 0.001). EpCAM+ CTCs displayed cancer stem cell biomarkers (CD133 and ABCG2), epithelial-mesenchymal transition, Wnt pathway activation, high tumorigenic potential, and low apoptotic propensity.

Conclusion

: Stem cell–like phenotypes are observed in EpCAM+ CTCs, and a preoperative CTC7.5 of ≥2 is a novel predictor for tumor recurrence in HCC patients after surgery, especially in patient subgroups with AFP levels of ≤400 ng/mL or low tumor recurrence risk. EpCAM+ CTCs may serve as a real-time parameter for monitoring treatment response and a therapeutic target in HCC recurrence.
Chronic intermittent hypoxia aggravates intrahepatic endothelial dysfunction in cirrhotic rats
Authors: Hernández-Guerra Manuel , de Ganzo Zaida Adrián , González-Méndez Yanira , Salido Eduardo , Abreu Pedro , Moreno Miguel , Felipe Vanesa , Abrante Beatriz , Quintero Enrique
Published: November 2012

Chronic intermittent hypoxia (CIH) occurs with obstructive sleep apnea syndrome (OSAS) and provokes systemic endothelial dysfunction, which is associated with oxidative stress and low nitric oxide (NO) bioavailability. Cirrhotic livers exhibit intrahepatic endothelial dysfunction, which is characterized by an impaired endothelium-dependent response to vasodilators and hyperresponse to vasoconstrictors. We hypothesized that CIH may also contribute to intrahepatic endothelial dysfunction in cirrhosis. Normal and cirrhotic rats were exposed for 14 days to repetitive cycles of CIH mimicking OSAS in humans, or caged with room air (handled controls [HC]). Hepatic endothelial function was assessed in isolated and perfused rat livers by dose-response curves to acetylcholine (ACh) and methoxamine (Mtx). In a group of cirrhotic rats,

in vivo

systemic and hepatic hemodynamic parameters were evaluated at baseline and after volume expansion. In addition, liver samples were obtained to assess endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), NO bioavailability, and nitrotyrosinated proteins as a marker of oxidative stress. Cirrhotic rats exposed to CIH exhibited an attenuated vasodilatory response to ACh and hyperresponse to Mtx compared with HC rats. During volume expansion, similar portal pressure increases were observed in CIH and HC rats, although the mean arterial pressure increase was lower after CIH. These functional responses were associated with the presence of increased hepatic oxidative stress without changes in p-eNOS after CIH exposure. In normal rats, no hemodynamic changes were found.

Conclusion

: CIH exacerbates intrahepatic endothelial dysfunction in cirrhotic rats, which is associated with increased oxidative stress that may reduce NO bioavailability. Clinical studies are needed to assess whether OSAS contributes to endothelial impairment in human patients with cirrhosis.