bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cover Picture: A Novel Bis(zinc–porphyrin)–Oxoporphyrinogen Donor–Acceptor Triad: Synthesis, Electrochemical, Computational and Photochemical Studies (Eur. J. Org. Chem. 3/2006)
Authors: Hill Jonathan P. , Sandanayaka Atula S. D. , McCarty Amy L. , Karr Paul A. , Zandler Melvin E. , Charvet Richard , Ariga Katsuhiko , Araki Yasuyuki , Ito Osamu , D'Souza Francis 
Published: January 2006

AbstractThe cover picture shows an example of an oxoporphyrinogen molecule substituted at macrocyclic nitrogen atoms with zinc–porphyrins (oxoporphyrinogen gets zinc–porphyrin “wings”). The electrochemical and photochemical behaviour of this unprecedented tetrapyrrolic triad has been investigated using physical and computational methods. Evidence for the energy transfer and charge separation between the zinc–porphyrin “wings” and the quinonoid oxoporphyrinogen scaffold is discussed in the article by J. P. Hill, O. Ito, F. D'Souza et al. on p. 595 ff.
An observation of unusual temperature effects for enantioselective CZE employing highly sulfated‐β‐cyclodextrin
Authors: Westall Anne , Malmström Torsten , Petersson Patrik 
Published: January 2006

AbstractIn this paper data are presented suggesting that for enantiomers of basic and neutral analytes, the concentrations of highly sulfated CDs typically used are above the optimum since lower concentrations result in unacceptable migration times. This situation arises because of the high binding affinities often obtained with sulphated CDs. In a system being over the optimum CD concentration increasing the temperature of the capillary offers a capability to improve selectivity and reduce migration times.
Recent advances of transient isotachophoresis‐capillary electrophoresis in the analysis of small ions from high‐conductivity matrices
Authors: Timerbaev Andrei R. , Hirokawa Takeshi 
Published: January 2006

AbstractSince its invasion into the field of small ion analysis, quantitation of trace ionic analytes has always been a challenging task for CE, especially when dealing with highly saline samples. This review summarizes the method's progress and significant developments in the area due to its combination with on‐line preconcentration by transient ITP (tITP). Principles of tITP stacking in high‐conductivity solutions and operational preconcentration modes are considered. The most important application areas covered in this review include the analysis of seawater and biological fluids (urine, serum, etc.). Examples cited in this review demonstrate that tITP‐CE is now on a certain way of becoming a recognized technique when the determination of trace ionic species in loaded matrices is the aim.
Emission reduction of NOx and CO by optimization of the automatic control system in a coal‐fired stoker boiler
Authors: Schnelle Karl B. , Laungphairojana Atip , Debelak Kenneth A. 
Published: January 2006

AbstractTo date research on NOX and CO emission reduction in stoker‐fired boilers has been devoted to combustion modification to the overfire air, diverting air to a selected set of burners, using modified low‐NOX burners, using flue gas recirculation or flue gas treatment with specially controlled catalyst and additives. This study introduces a concept that focuses on the dynamics of the boiler and the automatic control system. The objective of this study was to reduce the NO and CO emissions by restructuring the automatic control system and then tuning the control system with parameters that have been optimized with emission reduction as the objective. Dynamic data were obtained from a step‐input test of either the underfire air or the overfire air. These data were used to model the boiler with a transfer function describing the emissions. The analyzer dynamic response was included in the overall model. The control parameters were determined from this overall emissions transfer function by mathematical optimization. These control parameters constituted the initial values in the automatic control system used for the final tests in the boiler. Additional adjustments to reduce the emissions were carried out during boiler operation. A low controller gain and a fast reset time were found to be the most suitable setting for the control system. The NO emissions controlled by the overfire air and CO emissions controlled by the underfire air produced the best results. Through this process, emission reduction in boiler No. 7 of the steam plant at Vanderbilt University of NO from 0.349 to 0.292 lb/106 BTU and CO emission from 0.135 to 0.0821 lb/106 BTU was obtained from the optimization of the control parameters of the automatic control system. © 2006 American Institute of Chemical Engineers Environ Prog, 2006
STAT3 ser727 phosphorylation and its association with negative estrogen receptor status in breast infiltrating ductal carcinoma
Authors: Yeh Yao‐Tsung , Ou‐Yang Fu , Chen I‐Fen , Yang Sheau‐Fang , Wang Yuan‐Yung , Chuang Hung‐Yi , Su Jinu‐Huang , Hou Ming‐Feng , Yuan Shyng‐Shiou F. 
Published: January 2006

AbstractAlthough it is known that STAT3 transcriptional activity is modulated by phosphorylation at serine residue 727, the role of STAT3 serine phosphorylation in breast cancer remains mostly unexplored. In this study, we examined the expression patterns of serine residue 727‐phosphorylated STAT3 (p‐ser727‐STAT3) in breast infiltrating ductal carcinoma tissues and nearby noncancer tissues by using immunoblotting techniques, and correlated the expression profiles with clinicopathological characteristics. A significantly elevated p‐ser727‐STAT3 expression was observed in 61.8% (42/68) of breast cancer tissues as compared to corresponding noncancer tissues (p < 0.001). Further, immunohistochemical analysis also showed an increased nuclear p‐ser727‐STAT3 staining in cancer lesions. The increased p‐ser727‐STAT3 expression in breast infiltrating ductal carcinoma tissues correlated significantly with negative estrogen receptor (ER) status, increased stage of cancer and increased tumor size (p = 0.001, 0.024 and 0.014, individually). Intriguingly, we noticed that the expression levels of p‐ser727‐STAT3 in ER‐negative breast cancer cell lines were higher than those in ER‐positive breast cancer cell lines. In ER‐positive MCF7 cells, treatment with ERα‐specific siRNA increased, whereas treatment with anticancer drug tamoxifen decreased the expression of p‐ser727‐STAT3, phenomena not observed in ER‐negative MDA‐MB‐231 cells. In conclusion, our results suggest that p‐ser727‐STAT3 may be involved in the pathogenesis of breast cancer in an ER‐dependent manner. © 2006 Wiley‐Liss, Inc.
Prognostic impact of orotate phosphoribosyl transferase among 5‐fluorouracil metabolic enzymes in resectable colorectal cancers treated by oral 5‐fluorouracil‐based adjuvant chemotherapy
Authors: Ochiai Takumi , Nishimura Kazuhiko , Noguchi Hajime , Kitajima Masayuki , Tsukada Akira , Watanabe Emiko , Nagaoka Isao , Futagawa Shunji 
Published: January 2006

AbstractOrotate phosphoribosyl transferase (OPRT) is the main enzyme that involves in phosphoribosylation of 5‐fluorouracil (5‐FU), an essential step that leads to tumor growth inhibition. In our study, the prognostic relevance of OPRT, thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) in resectable colorectal cancer (CRC) patients treated by oral 5‐FU were compared to further clarify the prognostic value of OPRT. Tumor tissue was collected from 90 CRC patients and the patients were followed for 5.2 years (Median). TS, DPD and OPRT activities in the extract of tumor tissue were determined enzymatically. The cut‐off value of OPRT (0.147 nmol/(min mg), TS (0.044 pmol/mg) and DPD (72.10 pmol/(min mg) were determined by maximal χ2 method. Among these 5‐FU metabolic enzymes, only high OPRT group demonstrated significantly better disease‐free survival (DFS) (p = 0.0152) and better overall survival (p = 0.0078). In Cox regression analysis, node status (p < 0.0005) and OPRT (p = 0.044) were significant factors for DFS. OPRT activity in tumor tissue was a predictor of prognosis in resectable CRC patients treated by oral 5‐FU‐based adjuvant chemotherapy, and was useful to pick‐up high risk patients independent from known prognosis factors. © 2006 Wiley‐Liss, Inc.
Quantification of the expression and inducibility of 12 rat cytochrome P450 isoforms by quantitative RT–PCR
Authors: Caron Etienne , Rioux Nathalie , Nicolas Olivier , Lebel‐Talbot Hugo , Hamelin Bettina A. 
Published: January 2006

AbstractThe administration of xenobiotics may significantly alter the expression of cytochromes P450 (CYPs), thereby leading to potentially toxic cellular, physiologic, and pharmacologic responses. Indeed, an important task in the development of new therapeutic entities is to evaluate efficiently and quantitatively their potential effects on the expression level of different CYPs. In this report, reverse transcriptase polymerase chain reaction (RT–PCR) was used to measure basal and induced mRNA of a wide range of rat CYP isoforms. Rats (n= 3 per treatment) were treated with five prototype inducers of CYP isoforms or with vehicle only. RT and PCR efficiencies were determined using appropriate RNA and DNA standards. Messenger RNA was quantified by PicoGreen standard curves and normalized to cyclophilin. Quantitative RT–PCR was used successfully to demonstrate that CYP isoforms were induced at the mRNA level following drug administration. Notably, phenobarbital resulted in significant induction of CYP2B1, CYP2B2, CYP2C6, CYP2C13, CYP2E1, CYP3A1, and CYP3A2. 3‐Methylcholanthrene induced CYP1A1, CYP1A2, and CYP1B1. CYP2C11 expression was highly variable and suppressed by pyridine, whereas the expression of CYP2E1 was suppressed by dexamethasone. We demonstrated that quantitative RT–PCR can be used to evaluate efficiently the effect of compounds on the expression of a wide range of CYP isoforms. The technique is advantageous over others in that it is very sensitive, efficient and applicable to highly homologous CYP isoforms. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:368–378, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20103
18F‐labelling of a potent nonpeptide CCR1 antagonist: synthesis of 1‐(5‐chloro‐2‐{2‐[(2R)‐4‐(4‐[18F]fluorobenzyl)‐2‐methylpiperazin‐1‐yl]‐2‐oxoethoxy}phenyl)urea in an automated module
Authors: Mäding P. , Füchtner F. , Johannsen B. , Steinbach J. , Hilger C. S. , Friebe M. , Halks‐Miller M. , Horuk R. , Mohan R. 
Published: January 2006

AbstractThe synthesis of 1‐(5‐chloro‐2‐{2‐[(2R)‐4‐(4‐[18F]fluorobenzyl)‐2‐methylpiperazin‐1‐yl]‐2‐oxoethoxy}phenyl)urea ([18F]4), a potent nonpeptide CCR1 antagonist, is described as a module‐assisted two‐step one‐pot procedure. The final product was obtained utilizing the reductive amination of the formed 4‐[18F]fluorobenzaldehyde (2) with a piperazine derivative 3 and sodium cyanoborohydride. After HPLC purification of the final product [18F]4, its solid phase extraction, formulation and sterile filtration, the isolated (not decay‐corrected) radiochemical yields of [18F]4 were between 7 and 13% (n=28). The time of the entire manufacturing process did not exceed 95 min. The radiochemical purity of [18F]4 was higher than 95%, the chemical purity ⩾60% and the enantiomeric purity >99.5%. The specific radioactivity was in the range of 59–226 GBq/µmol at starting radioactivities of 23.6–65.0 GBq [18F]fluoride. Copyright © 2006 John Wiley & Sons, Ltd.
Simple synthesis of [1‐11C]acetate
Authors: Le Bars D. , Malleval M. , Bonnefoi F. , Tourvieille C. 
Published: January 2006

Abstract[1‐11C]Acetate is prepared by carboxylation of a Grignard reagent, CH3MgBr, on a simple polyethylene loop with cyclotron‐produced [11C]carbon dioxide, followed by hydrolysis and purification on solid‐phase extraction cartridges. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and liposome encapsulation of a novel 18F‐conjugate of ω‐conotoxin GVIA for the potential imaging of N‐type Ca2+ channels in the brain by positron emission tomography
Authors: Azarian Vahe , Gangloff Anne , Seimbille Yann , Delaloye Sibylle , Czernin Johannes , Phelps Michael E. , Silverman Daniel H.S. 
Published: January 2006

Abstractω‐Conotoxin GVIA is a potent, irreversible antagonist of N‐type voltage gated Ca2+ channels. A radiofluorinated analogue of GVIA could be useful in assessing regional synaptic density of the brain, in vivo, using positron emission tomography. N‐hydroxy succinimidyl 4‐[18F]fluorobenzoate was employed to site‐specifically label GVIA, preserving native binding affinity. The tracer was characterized with MALDI‐TOF mass spectrometry and colorimetric protein assay. Radiochemical decay‐corrected yield of the lysine‐24 labeled analogue of [18F]GVIA was 5%. Specific activity of this species was determined to be 1.2 × 105 Ci/mmol. Encapsulation of the tracer in sulfatide containing liposomes, a potential method for enhancing blood–brain penetrance, was accomplished with 40% efficiency. Copyright © 2006 John Wiley & Sons, Ltd.
Evolution and homology of the astragalus in early amniotes: New fossils, new perspectives
Authors: O'Keefe F. Robin , Sidor Christian A. , Larsson Hans C.E. , Maga Abdoudaye , Ide Oumarou 
Published: January 2006

AbstractThe reorganization of the ankle in basal amniotes has long been considered a key innovation allowing the evolution of more terrestrial and cursorial behavior. Understanding how this key innovation arose is a complex problem that largely concerns the homologizing of the amniote astragalus with the various ossifications in the anamniote tarsus. Over the last century, several hypotheses have been advanced homologizing the amniote astragalus with the many ossifications in the ankle of amphibian‐grade tetrapods. There is an emerging consensus that the amniote astragalus is a complex structure emerging via the co‐ossification of several originally separate elements, but the identities of these elements remain unclear. Here we present new fossil evidence bearing on this contentious question. A poorly ossified, juvenile astragalus of the large captorhinid Moradisaurus grandis shows clear evidence of four ossification centers, rather than of three centers or one center as posited in previous models of astragalus homology. Comparative material of the captorhinid Captorhinikos chozaensis is also interpretable as demonstrating four ossification centers. A new, four‐center model for the homology of the amniote astragalus is advanced, and is discussed in the context of the phylogeny of the Captorhinidae in an attempt to identify the developmental transitions responsible for the observed pattern of ossification within this clade. Lastly, the broader implications for amniote phylogeny are discussed, concluding that the neomorphic pattern of astragalus ossification seen in all extant reptiles (including turtles) arose within the clade Diapsida. J. Morphol. © 2006 Wiley‐Liss, Inc.
Ultrastructure of tarsal sensilla and other integument structures of two Pseudocellus species (Ricinulei, Arachnida)
Authors: Talarico Giovanni , Palacios‐Vargas José G. , Fuentes Silva Mariano , Alberti Gerd 
Published: January 2006

AbstractRicinuleids are one of the least investigated groups of Arachnida. In particular, knowledge of their ultrastructure is poor. Observations of the distal tarsomeres of ricinuleids show differences in their shape and equipment of surface structures. Legs I and II are used by the Ricinulei to explore their surroundings with tentative movements. The tarsomeres of these legs show similarities in shape and surface structures that distinguish them from those of legs III and IV. In this study, 11 different structures of the tarsomere surfaces of two cave‐dwelling species, Pseudocellus pearsei and P. boneti from México, were investigated for the first time with scanning and transmission electron microscopy and discussed regarding their possible function: 1) a single treelike ramifying seta resembles a no pore single‐walled (np‐sw) sensillum; 2) setae occurring in a small number and possessing a bipartite shaft represent terminal pore single‐walled (tp‐sw) sensilla. The surface of the proximal half of the shaft shows small branches. The distal half has a smooth surface; 3) long setae with conspicuous longitudinal lamellae show characteristics of chemoreceptive wall pore single‐walled (wp‐sw) sensilla; 4) frequent small wp‐sw sensilla with flat and irregular lamellae; 5) very short wp‐sw sensilla occurring solitary or in groups; 6) a few short setae with smooth surface correspond to wp‐sw sensilla; 7) a single short clubbed seta articulating in a flat pit is considered to be a np‐sw sensillum; 8) common long setae with a pointed tip show characteristics of mechanoreceptive np‐sw sensilla; 9) ventral setae with adhesive and mechanosensory function are accompanied by multicellular “class III” glands; 10) slit organs with mechanoreceptive function; and 11) dome‐like tubercles with no indication of sensorial function. Several of these sensilla form a sensory field on the dorsofrontal surface which is particularly pronounced on the distal tarsomeres of legs I and II. J. Morphol. © 2006 Wiley‐Liss, Inc.
Preparative separation of a multicomponent peptide mixture by mass spectrometry
Authors: Yang Xinli , Mayer Philip S. , Tureček František 
Published: January 2006

AbstractWe report on the first multiplex preparative separation by mass spectrometry of bio‐organic molecules in the 200–350 Da mass range that is typical for synthetic drugs. A five‐component mixture consisting of two di‐ and three tripeptides has been separated by mass using a specially designed mass spectrometer. The instrument for preparative separations consists of an electrospray ionization (ESI) source, ion transfer optics, an electrostatic sector, and an inhomogeneous‐field magnetic mass analyzer that achieves linear mass dispersion of ion beams. Protonated peptides produced by electrospray were separated, nondestructively landed on a 16‐channel array of dry collector plates, and reconstituted in solution. The preparation procedures and the instrumental conditions have been optimized to maximize the ion currents. The significant features of the special mass spectrometer are high ion currents and simultaneous separation and collection of mixture components. Copyright © 2006 John Wiley & Sons, Ltd.
Study of phytochelatins and other related thiols as complexing biomolecules of As and Cd in wild type and genetically modified Brassica juncea plants
Authors: Navaza Ana Pereira , Montes‐Bayón Maria , LeDuc Danika L. , Terry Norman , Sanz‐Medel Alfredo 
Published: January 2006

AbstractThe accumulation of As and Cd in Brassica juncea plants and the formation of complexes of these elements with bioligands such as glutathione and/or phytochelatins (PCs) is studied. The genetic manipulation of these plants to induce higher As and Cd accumulation has been achieved by overexpressing the genes encoding for gamma‐glutamyl cysteine synthetase (γ‐ECS) and glutathione synthetase (GS). These two enzymes are responsible for glutathione (GSH) formation in plants, which is the first step in the production of PCs. The biomass produced in both the wild type and the genetically modified plants, has been evaluated. Additionally, the total Cd and As concentration accumulated in the plant tissues was measured by inductively coupled plasma mass spectrometry (ICP‐MS) after extraction. Speciation studies on the extracts were conducted using size exclusion liquid chromatography (SEC) coupled online with ICP‐MS to monitor As, Cd and S. For further purification of the As fractions, reversed phase high performance liquid chromatography (RP‐HPLC) was used. Structural elucidation of the PCs and other thiols, as well as their complexes with As and Cd, was performed by electrospray‐quadrupole‐time‐of‐flight (ESI‐Q‐TOF). In both the Cd and As exposed plants it was possible to observe the presence of oxidized PC2 ([M + H]+, m/z 538), GS‐PC2(‐Glu) ([M + H]+, m/z 716) as well as reduced GSH ([M + H]+, m/z 308) and oxidized glutathione (GSSG) ([M + H]+, m/z 613). However, only the GS plants exhibited the presence of As(GS)3 complex ([M + H]+, m/z 994) that was further confirmed by MS/MS. This species is reported for the first time in B. juncea plant tissues. Copyright © 2006 John Wiley & Sons, Ltd.
Mass spectrometric characterization of efaproxiral (RSR13) and its implementation into doping controls using liquid chromatography–atmospheric pressure ionization‐tandem mass spectrometry
Authors: Thevis Mario , Krug Oliver , Schänzer Wilhelm 
Published: January 2006

AbstractEfaproxiral (2‐[4‐[[(3,5‐dimethylanilino)carbonyl]methyl]phenoxyl]‐2‐methylpropionic acid, formerly referred to as RSR13) is prohibited in sports according to the World Anti‐Doping Agency (WADA). The drug as well as structurally related compounds and a stable isotope‐labeled derivative have been synthesized to elucidate the fragmentation pathway of efaproxiral, using electrospray ionization (ESI) and tandem mass spectrometry by employing a novel linear ion trap—orbitrap hybrid mass spectrometer—in positive and negative ionization modes. The elimination of 2‐methyl acrylic acid (−86 u) has been identified as a major fragmentation process in both charge states. Negative ionization and collision‐induced dissociation (CID) caused an additional release of carbon dioxide (−44 u), and positive ionization the loss of formic acid (−46 u). Efaproxiral was incorporated into an existing screening procedure for doping controls using solid‐phase extraction (SPE) followed by liquid chromatography‐tandem mass spectrometry, enabling a limit of detection of 2.5 ng/ml and interday precisions ranging from 7.9 to 13.0%. Copyright © 2006 John Wiley & Sons, Ltd.
Zirconocene Propylene Polymerisation: Controlling Termination Reactions
Authors: Tynys Antti , Eilertsen Jan L. , Rytter Erling 
Published: January 2006

AbstractSummary: Propylene was polymerised at varying trimethylaluminium (TMA) concentration with two metallocenes activated by methylaluminoxane (MAO) in an attempt to better understand the effect of TMA on the activation process, catalyst activity and termination reactions. A chemical treatment of MAO solution with 2,6‐di‐tert‐butyl‐p‐cresol was used to obtain TMA‐free polymerisation conditions. The metallocene precursors under investigation were diphenylmethyl(cyclopentadienyl)(9‐fluorenyl)zirconium dichloride (1) and rac‐dimethylsilylbis(4‐tert‐butyl‐2‐methyl‐cyclopentadienyl)zirconium dichloride (2). Chain transfer to aluminium was the dominating termination route for 1/MAO accompanied with β‐H/β‐CH3 transfer to Zr and β‐H transfer to monomer. It was found that β‐H/β‐CH3 transfer to Zr was favoured over the β‐H transfer to monomer at elevated temperatures, and that polymerisation and β‐H transfer to monomer depended on the same critical reaction. For 2/MAO the detected termination routes were β‐H transfer to Zr and chain transfer to aluminium. A strong activity dependency on TMA concentration was observed. With 1/MAO high TMA concentration decreased and stabilised the activity, whereas TMA free polymerisation conditions at 40 °C increased markedly the activity, indicating that TMA coordinated to the active site of 1/MAO. Surprisingly, with more sterically hindered 2/MAO, high TMA concentration increased the activity and nearly complete activity loss occurred at TMA‐free polymerisation conditions at 40 °C.Metallocene precursors for investigation of propylene polymerisation.magnified imageMetallocene precursors for investigation of propylene polymerisation.