bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of laryngopharyngeal reflux in patients with premalignant or early carcinomas of the larynx
Authors: Lewin Jan S. , Gillenwater Ann M. , Garrett J. David , Bishop‐Leone Julie K. , Nguyen Dominic D. , Callender David L. , Ayers Gregory D. , Myers Jeffrey N. 
Published: February 2003

AbstractBACKGROUNDAn association between laryngopharyngeal reflux (LPR) and laryngeal carcinoma has been suggested, but remains unproven. The current pilot study was performed to determine the incidence of LPR among patients with early laryngeal carcinomas or dysplasia and to examine the associations between levels of LPR and histologic stage, smoking status, the symptom of heartburn, and body position during reflux episodes.METHODSBehavioral and 24 hour pH monitoring data were prospectively acquired and analyzed for 40 previously untreated adults with dysplasia, T1or T2 laryngeal carcinomas.RESULTSEighty‐five percent of patients had LPR. No significant association was shown between the level of LPR and histologic stage or smoking status. Heartburn did not predict LPR. The incidence of LPR in the upright body position was 91%, compared with 9% in the supine position, among patients with LPR.CONCLUSIONSWhen compared to available normative data, the current findings show a high incidence of LPR in patients with premalignant and early laryngeal cancer. These findings highlight the need for a matched‐control study evaluating LPR as a potential predisposing factor for laryngeal carcinoma. Cancer 2003;97:1010–4. © 2003 American Cancer Society.DOI 10.1002/cncr.11158
Combination chemotherapy for desmoid tumors
Authors: Okuno Scott H. , Edmonson John H. 
Published: February 2003

AbstractBACKGROUNDDesmoid tumor (aggressive fibromatosis) is an aggressive fibroblastic proliferation of well circumscribed, locally invasive, differentiated fibrous tissue. For patients with desmoid tumors that are not amenable to surgery or radiation therapy, the use of hormonal agents and nonsteroidal antiinflammatory drugs (NSAIDs) have been attempted, with some success. The use of chemotherapy also has been reported to have activity.METHODSSeven patients (5 males and 2 females) with a median age of 40 years (range, 17–66 years) who received cytotoxic chemotherapy (combinations of cyclophosphamide and doxorubicin; mitomycin, doxorubicin, and cisplatin; and ifosfamide and etoposide) for desmoid tumor were reviewed retrospectively. Five patients were found to have recurrent tumors. Four patients had familial adenomatous polyposis. Four patients had failed tamoxifen and six had failed NSAIDs prior to receiving cytotoxic chemotherapy. In six patients the desmoid tumor was intraabdominal and one tumor had occurred on the buttock.RESULTSPatients received a median number of six cycles of chemotherapy (range, two to eight cycles). Objective disease regression occurred in 3 patients. There was an apparent clinical benefit in six patients with the duration of benefit ranging from 3 months to 15 years. The chemotherapy was well tolerated and no treatment‐related mortality was reported.CONCLUSIONSThe results of the current study indicate that the use of combination chemotherapy for desmoid tumors may provide long‐term clinical benefits. Cancer 2003;97:1134–35. © 2003 American Cancer Society.DOI 10.1002/cncr.11189
Complete cytogenetic and molecular responses to interferon‐α‐based therapy for chronic myelogenous leukemia are associated with excellent long‐term prognosis
Authors: Kantarjian Hagop M. , O'Brien Susan , Cortes Jorge E. , Shan Jianqin , Giles Francis J. , Rios Mary Beth , Faderl Stefan H. , Wierda William G. , Ferrajoli Alessandra , Verstovsek Srdan , Keating Michael J. , Freireich Emil J. , Talpaz Moshe 
Published: February 2003

AbstractBACKGROUNDLittle is known regarding long‐term prognosis among patients with Philadelphia chromosome (Ph)‐positive chronic myelogenous leukemia (CML) who achieve a complete cytogenetic response (0% Ph‐positive cells) after treatment with interferon‐α.METHODSThe authors analyzed 512 patients with Ph‐positive, early chronic‐phase CML who were treated with interferon‐based therapies between 1981–1995 for the incidence and durability of complete cytogenetic response, and in relation to long‐term prognosis.RESULTSOne hundred forty patients (27%) achieved a complete cytogenetic response. Their 10‐year survival rate was 78%. At the time of last follow‐up, 44 patients (31%, 9% of the total) were alive, 21 in first and 23 in second durable complete cytogenetic response (median, 127 months; range, 88–191 months); 39 patients had not received any therapy for a median of 50 months (range, 11–139 months). Analysis by reverse transcriptase‐polymerase chain reaction in 78 patients during complete cytogenetic response showed 46 who had achieved at least 1 complete molecular response. Five of these 78 patients had died by the time of last follow‐up, but only 2 had died of disease‐specific causes. Recurrence rates were significantly lower and cytogenetic response durations were significantly longer among patients who achieved at least one complete molecular response.CONCLUSIONSAchieving a complete cytogenetic or molecular response after therapy with interferon‐α appears to be associated with excellent long‐term prognosis. Approximately 10% of patients reportedly can achieve durable complete cytogenetic response, with or without continuation of interferon. This finding emphasizes the potential of long‐term event‐free survival in CML patients outside the context of allogeneic stem cell transplantation, which may be improved with new therapies such as imatinib mesylate. Cancer 2003;97:1033–41. © 2003 American Cancer Society.DOI 10.1002/cncr.11223
Robust direction‐of‐arrival estimation against array sensor errors using Hopfield neural network
Authors: Yamaoka Tateo , Masada Shiori , Sato Satoshi , Hamada Nozomu 
Published: February 2003

AbstractWhen direction‐of‐arrival estimation methods based on eigenvalue expansion such as MUSIC and ESPRIT are applied to an ideal sensor array, high resolution can be attained. However, if there exist array sensor errors due to sensor position errors and degradation of the phase shifters, significant errors may arise in the estimation results. Also, in order to obtain sufficient estimation accuracy, a relatively high signal‐to‐noise ratio is required in the array input. In this paper, the Hopfield neural network is employed for direction‐of‐arrival estimation and a direction‐of‐arrival estimation method that is robust to array errors by virtue of using training signals is proposed. By means of computer simulation, the method is compared with that of MUSIC and its effectiveness is verified. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 19–28, 2003; Pub‐lished online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10062
A neural network model of memory system using hippocampus
Authors: Ito Makoto , Kuroiwa Jousuke , Miyake Shogo 
Published: February 2003

AbstractWhen an episodic memory is to be transferred from short‐term memory to long‐term memory, there must be a buffer mechanism that temporarily stores the content of the short‐term memory as a mid‐term memory. It is considered that the hippocampus plays that role. In composing an episodic memory, there must be not only the association of different events without a time factor (spatial pattern), but also the association of different events containing time factors (time sequence pattern). This paper proposes a hippocampus neural network model, based on anatomical and physiological knowledge. The model features the following points. (i) By applying a learning rule where the input history is considered in the hippocampus CA3, which is regarded to have the associative recall function, it is made possible for the model to learn the time sequence pattern. (ii) The orthogonal coding function is provided in the gyrus dentatus, and the decoding function is provided in the hippocampus CA1. It is expected that the memory capacity of the hippocampus will be enlarged by providing the orthogonal coding function. It is shown by a numerical simulation that the mid‐term memory can learn spatial and time sequence patterns, and that associative recall of the memory contents can be realized. This result implies that the proposed hippocampus model can retain episodic memory as a mid‐term memory. The obtained results agree with physiological data, and demonstrate the effectiveness of the proposed model. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(6): 86–97, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1010
Sequential Metathesis in Oxa‐ and Azanorbornene Derivatives
Authors: Arjona Odón , Csákÿ Aurelio G. , Plumet Joaquín 
Published: February 2003

AbstractRing‐opening metathesis (ROM), when applied to the synthesis of bicyclic alkenes, is the basis of ring‐opening‐metathesis polymerisation (ROMP). This polymerisation reaction can be suppressed in the presence of a second open‐chain olefin thus combining the ROM with an intermolecular cross metathesis (CM). In conveniently substituted bicyclic derivatives a third metathetical reaction — ring closing metathesis (RCM) — can be achieved, giving new substituted bicyclic systems. In this account the results of these tandem metathetical reactions performed on oxa‐ and azabicyclic norbornenic derivatives are highlighted. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A New Crystalline Zwitterionic Product from the Reaction of Bu3P and DMAD
Authors: Aitken R. Alan , Costello Stephen J. , Slawin Alexandra M. Z. , Wilson Neil J. 
Published: February 2003

AbstractTributylphosphane reacts with DMAD to give the crystalline adduct 2 which is stabilised by extensive delocalisation and whose formation involves an unusual rearrangement. The isomeric structure 7 for the previously reported adduct with triphenylphosphane is supported by 13C NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Investigations into the Regioselective C‐Deuteration of Acyclic and Exocyclic Enolates
Authors: Eames Jason , Coumbarides Gregory S. , Suggate Michael J. , Weerasooriya Neluka 
Published: February 2003

AbstractResults are reported on the regioselective C‐deuteration of a series of related acyclic and exocyclic enolates derived from substituted aryl ketones. We comment on factors, such as the presence of additives and the structural nature of the enolate, that influence the observed C‐deuteration and discuss the role of the deuterium donor. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Columbetdione, a New Cyclopentene Derivative from the Fruiting Bodies of Tricholoma columbetta (Basidiomycetes) − Structure and Synthesis
Authors: Vadalà Alessandro , Finzi Paola Vita , Zanoni Giuseppe , Vidari Giovanni 
Published: February 2003

AbstractA chemical investigation of the fruiting bodies of Tricholoma columbetta (Agaricaceae, Basidiomycetes) led to the isolation of columbetdione, an unprecedented cyclopentene derivative. The structure was determined by spectroscopic methods and molecular modelling and unambiguously confirmed by total synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Straightforward Synthesis of Labeled and Unlabeled Pyrimidine d4Ns via 2′,3′‐Diyne seco Analogues through Olefin Metathesis Reactions
Authors: Gillaizeau Isabelle , Lagoja Irene M. , Nolan Steve P. , Aucagne Vincent , Rozenski Jef , Herdewijn Piet , Agrofoglio Luigi A. 
Published: February 2003

AbstractThe synthesis of dideoxynucleosides (ddNs) or didehydro‐dideoxynucleosides (d4Ns) from nucleosides has been extensively reviewed. While previously described methods are based on the modification of the 2′‐ and/or 3′‐OH group of the intact ribose moiety, the use of a ring‐closing metathesis (RCM) for the formation of the unsaturated cyclic system of nucleosides could be a straightforward approach to the d4Ns. Thus, as part of our drug labeling program, this paper reports a straightforward synthesis of 2′,3′‐didehydro‐2′,3′‐dideoxyuridine (d4U) and [1′,2′,3′,4′,5′‐13C5,6‐13C,1,3‐15N2]d4T using the RCM protocol. This paper discusses the preparation of nucleoside dienes and the activity of ruthenium‐based metathesis catalysts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Determination of the Absolute Configuration of Hydroxyiridals by Chiroptical and NMR Spectroscopic Methods
Authors: Lamshöft Marc , Schmickler Hans , Marner Franz‐Josef 
Published: February 2003

AbstractHydroxyiridals − monocyclic triterpenoids − are found abundantly in sword lilies. They feature a homofarnesyl side chain that is hydroxylated at one of the allylic methylene groups, which gives rise to a chiral carbon atom. The absolute configuration of six hydroxyiridals from different sources was determined by the exciton chirality method and by NMR spectroscopy of the diastereoisomeric MTPA and MPA esters. All three measurements gave consistent results, establishing the (R) configuration for all of the hydroxyiridals. The reliability of these methods for the stereochemical analysis of acyclic secondary allylic alcohols was confirmed by applying them to a synthetic model compound of known configuration. In the course of this study, two new iridals − 16,26‐dihydroxyiridal 7 and 18,19‐epoxyiridal 8 − were isolated from extracts of I. versicolor and the iridal fraction of I. missouriensis was analyzed thoroughly. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture: Eur. J. Org. Chem. 4/2003
Authors: van Axel Castelli Valeria , Dalla Cort Antonella , Mandolini Luigi , Reinhoudt David N. , Schiaffino Luca 
Published: February 2003

AbstractThe cover picture shows the four‐body productive complex involved in the rate‐determining step of the addition of a triethylamine‐activated benzenethiol to a uranyl−salophenactivated 2‐cyclopenten‐1‐one. The background offers a view of the complex rate equation ad hoc developed for the above (two reactant)‐(two catalyst) system involving complexation catalysis and product inhibition. Details are discussed in the article by L. Mansolini, D. N. Reinhoudt et al. on p. 627 ff.
Synthesis of Pyrrole Derivatives through Functionalization of 3,4‐Bis(lithiomethyl)dihydropyrroles
Authors: Barluenga José , Fañanás Francisco J. , Sanz Roberto , Ignacio José M. 
Published: February 2003

AbstractBis(2‐lithioallyl)amines 2, substituted at the double bonds, undergo intramolecular carbolithiation of a lithiated double bond in different solvents to afford dilithiated dihydropyrroles 3. Treatment of these dianions with electrophiles allows the preparation of functionalized pyrrole derivatives 5 and 6. Interestingly, treatment of these dianions with carboxylic esters selectively affords either keto or hydroxy compounds (9 or 10), depending on the conditions. Several experiments have been carried out in order to clarify the mechanism of this selective transformation. Finally, dilithiated dihydropyrrole 3a could be transformed in a three‐step procedure into the corresponding 3,4‐bis(bromomethyl) derivative 31, which can easily be converted into bicyclic pyrrole compounds 32−33 by treatment with different nucleophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Determination of Ytterbium Traces by Cathodic Stripping Voltammetry
Authors: Mlakar Marina 
Published: February 2003

AbstractThe method of ytterbium(III) trace concentration in the presence of 2‐thenoyltrifluoroacetone (TTA) and polyethyleneglycol (PEG) in ammonium chloride is described. The adsorption was performed at the HMDE at −1.0 V using linear scan voltammetry and square‐wave voltammetry. The relationship between properties of the SW response of the mixed ligand complex and parameters of a charge transfer were analyzed using theoretical data of SW redox processes.
Influence of the Mixed Adsorption Layer of 1‐Butanol/Toluidine Isomers on the Two Step Electroreduction of Zinc(II) Ions
Authors: Saba J. , Nieszporek J. , Gugala D. , Sienko D. , Szaran J. 
Published: February 2003

AbstractStudies of mixed adsorption layers with respect to their influence on kinetics of Zn2+ ions reduction indicate dynamics of this process in the presence of inhibitor and accelerating substances. This effect can be seen as a much greater increase of standard constant rates compared with a similar increase without the inhibitor. 1‐Butanol was used as an inhibitor in the studies and p‐toluidine and m‐toluidine as accelerating substances. The adsorption measurements show that in the range of Zn2+ ion reduction potentials in the solutions containing 1‐butanol and the definite isomer of toluidine, toluidine plays a dominant role in establishing equilibrium in the mixed adsorption layer. The obtained values of the true standard constant rates of the transfer of the first electron ks1t and the second electron ks2t indicate that in each of the studied systems the stage of the first electron transfer is more strongly accelerated compared with the stage of the second electron transfer. The linear character of the dependence ks1t and ks2t in the function of the surface excess and in the function of 1‐butanol concentration indicates that active complexes are formed for each case of the mixed adsorption layer.
Potential‐Controlled Chromatography of Short‐Chain Carboxylic Acids
Authors: Knizia M. W. , Vuorilehto K. , Schrader J. , Sell D. 
Published: February 2003

AbstractA chromatographic column was constructed which could be operated with an electrically conductive stationary phase of graphite particles. This column allowed chromatographic experiments at variable electric potentials of the column material. The chromatographic behavior of selected carboxylic acids was significantly influenced at positive column potentials. An equimolar mixture of three different carboxylic acids were separated at a potential of +600 mV (versus. Ag/AgCl). Surprisingly, the stereoisomers maleic and fumaric acid, which are identical in molecular mass and charge, could also be separated. Further improvements to the chromatographic performance were achieved by applying potential drops and linear potential gradients.
Mediated Electrocatalysis at the Electrodes Covered with [MIII(bpy)3](ClO4)3 (M=Co and Fe) in the Presence of Electroactive Solutes
Authors: Winkler Krzysztof , Plonska Marta E. , Basa Anna , Lach Magdalena , Balch Alan L. 
Published: February 2003

AbstractElectron transfer processes for selected redox systems (ferrocene0/+, decamethylferrocene0/+, N,N,N′,N′‐tetramethyl‐1,4‐phenylenediamine0/+, 7,7,8,8‐tetracyano‐quinonedimethane0/−/2−, cobaltocene0/+, C600/−, and benzoquinone0/−) at electrodes modified by precipitation of electrochemically inactive [MIII(bpy)3](ClO4)3 (M=Co and Fe, bpy=2,2′‐bipyridine) layers have been investigated by cyclic voltammetry and electrochemical quartz crystal microbalance studies. The mediation of heterogeneous electron transfer is observed for these systems. For an electrode modified with [MIII(bpy)3](ClO4)3, the rate of the electrocatalytic mediation process depends on the formal potential of the redox system. If the formal potential of the redox system is close to the potential of [CoII(bpy)3]2+ oxidation (as is the case with the decamethylferrocene0/+, N,N,N′,N′‐tetramethyl‐1,4‐phenylenediamine0/+ and 7,7,8,8‐tetracyanoquinonedimethane0/− systems), the rate of the electrode reaction is limited by the rate of the chemical reduction of the [CoIII(bpy)3](ClO4)3 solid phase by the reduced form of redox couple. For C60 and benzoquinone, which have more negative formal potentials for reduction, the rate of diffusion of the electroactive reactant to the electrode surface limits the rate of electrode process. The kinetics of mediated electrocatalysis are also affected by the solvent. In the case of the Fe(III)‐based layer, the diffusion of the electroactive reactant in the solution is the rate determining step for the catalytic process at the modified electrode for all studied systems. Electrodes modified with [FeIII(bpy)3](ClO4)3 have been used for the quantitative determination of electroactive compounds. For ferrocene and decamethylferrocene, a linear relationship between the catalytic reduction current and the concentration of reactant in the solution has been observed over the concentration range from 1 to 50 mM.
Enhancement of selectivity and resolution in the enantioseparation of uncharged compounds using mixtures of oppositely charged cyclodextrins in capillary electrophoresis
Authors: Abushoffa Adel M. , Fillet Marianne , Servais Anne‐Catherine , Hubert Philippe , Crommen Jacques 
Published: February 2003

AbstractThe enantiomeric separation of some nonsteroidal anti‐inflammatory drugs (NSAIDs) was investigated in capillary electrophoresis (CE) using dual systems with mixtures of charged cyclodextrin (CD) derivatives. A significant enhancement of selectivity and resolution could be achieved in the enantioseparation of these analytes in their uncharged form by the simultaneous addition of two oppositely charged CD derivatives to the background electrolyte. The combination of the single‐isomer cationic CD, permethyl‐6‐monoamino‐6‐monodeoxy‐β‐CD (PMMAβCD) and the single‐isomer polyanionic CD, heptakis‐6‐sulfato‐β‐cyclodextrin (HSβCD) in a pH 2.5 phosphoric acid‐triethanolamine buffer, was designed and employed for the enantioseparation of profens. The improvement in selectivity and resolution can be attributed to the fact that the two CDs, which lead to independent and enantioselective complexation with the analyte enantiomers, have not only opposite effects on the electrophoretic mobility of these compounds but also opposite affinity patterns towards the enantiomers of these compounds. Binding constants for these enantiomers with each CD were determined using linear regression approach, in order to be able to predict the effect of the concentrations of the two CDs on enantiomeric selectivity and resolution in such dual systems.
Synthesis, analytical characterization and use of octakis(2,3‐di‐O‐methyl‐6‐O‐sulfo)‐γ‐cyclodextrin, a novel, single‐isomer, chiral resolving agent in low‐pH background electrolytes
Authors: Busby M. Brent , Lim Peniel , Vigh Gyula 
Published: February 2003

AbstractThe third member of the family of single‐isomer, sulfated γ‐cyclodextrins, the sodium salt of octakis(2,3‐di‐O‐methyl‐6‐O‐sulfo)‐γ‐cyclodextrin has been synthesized, analytically characterized and used for the capillary electrophoretic separation of the enantiomers of nonionic, weak acid and weak base analytes in low‐pH aqueous background electrolytes. Though octakis(2,3‐di‐O‐methyl‐6‐O‐sulfo)‐γ‐cyclodextrin complexes less strongly with many of the analytes tested than the other members of the single‐isomer, 6‐O‐sulfo γ‐cyclodextrin family, such as octa(6‐O‐sulfo)‐γ‐cyclodextrin and octakis(2,3‐di‐O‐acetyl‐6‐O‐sulfo)‐γ‐cyclodextrin, it offers excellent separation selectivities, often complementary to those of both the single‐isomer, 6‐O‐sulfo β‐cyclodextrins and 6‐O‐sulfo γ‐cyclodextrins. Rapid, efficient enantiomer separations were observed for a large number of structurally diverse analytes in acidic aqueous background electrolytes.