bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micromorphology of Cotiga Mound, West Virginia
Authors: Cremeens D.L. 
Published: June 2005

AbstractMicromorphology samples from Cotiga Mound (ca. 2100 yr B.P.) reveal distinct microstructures associated with mound construction and post‐construction pedogenesis of the mound materials. The interface between layers of basketloads displays sharp, irregular contacts with little to no evidence of pedoturbation, suggesting rapid construction. Evidence of clay and iron translocation, along with well‐preserved charcoal fragments containing identifiable cell structure, were observed in samples collected from hearth features. Both the prepared surface and associated central burial feature at the base of the mound have a complex microstructure, characterized by charcoal layers and zones of clay accumulation, along with microstratification in the prepared surface. Clay translocation, formation of a complex void network, and ironmanganese accumulation were the dominant pedogenic processes that modified the completed mound. © 2005 Wiley Periodicals, Inc.
Paleoindian environmental change and landscape response in Barger Gulch, Middle Park, Colorado
Authors: Mayer James H. , Surovell Todd A. , Waguespack Nicole M. , Kornfeld Marcel , Reider Richard G. , Frison George C. 
Published: June 2005

AbstractMiddle Park, a high‐altitude basin in the Southern Rocky Mountains of north‐central Colorado, contains at least 59 known Paleoindian localities. At Barger Gulch Locality B, an extensive Folsom assemblage (˜10,500 14C yr B.P.) occurs within a buried soil. Radiocarbon ages of charcoal and soil organic matter, as well as stratigraphic positions of artifacts, indicate the soil is a composite of a truncated, latest‐Pleistocene soil and a younger mollic epipedon formed between ˜6000 and 5200 14C yr B.P. and partially welded onto the older soil following erosion and truncation. Radiocarbon ages from an alluvial terrace adjacent to the excavation area indicate that erosion followed by aggradation occurred between ˜10,200 and 9700 14C yr B.P., and that the erosion is likely related to truncation of the latest‐Pleistocene soil. Erosion along the main axis of Barger Gulch occurring between ˜10,000 and 9700 14C yr B.P. was followed by rapid aggradation between ˜9700 and 9550 14C yr B.P., which, along with the erosion at Locality B, coincides with the abrupt onset of monsoonal precipitation following cooling in the region ˜11,000–10,000 14C yr B.P. during the Younger Dryas oscillation. Buried soils dated between ˜9500 and 8000 14C yr B.P. indicate relative landscape stability and soil formation throughout Middle Park. Morphological characteristics displayed by early Holocene soils suggest pedogenesis under parkland vegetation in areas currently characterized by sagebrush steppe. The expansion of forest cover into lower elevations during the early Holocene may have resulted in lower productivity in regards to mammalian fauna, and may partly explain the abundance of early Paleoindian sites (˜11,000–10,000 14C yr B.P., 76%) relative to late Paleoindian sites (˜10,000–8000 14C yr B.P., 24%) documented in Middle Park. © 2005 Wiley Periodicals, Inc.
Kinetic study of hydrolysis of benzoates. Part XXIV—Variation of the ortho substituent effect with solvent in the alkaline hydrolysis of substituted phenyl benzoates
Authors: Nummert Vilve , Piirsalu Mare , Mäemets Vahur , Koppel Ilmar 
Published: June 2005

AbstractThe second‐order rate constants k2 (M−1 s−1) for the alkaline hydrolysis of meta‐, para‐ and ortho‐substituted phenyl benzoates, C6H5CO2C6H4X, in aqueous 0.5 M n‐Bu4NBr were measured spectrophotometrically. The dependence of substituent effects, especially ortho inductive, resonance and steric terms on different solvent parameters, was studied using the following equation:

where Δlog k=log kX−log kH, σI, σR0 and EsB are the inductive, resonance and steric substituent constants and E, Y and P are the solvent electrophilicity, polarity and polarizability parameters, respectively. In data treatment $\Delta E = E_{\rm S} - E_{{\rm H}_2 {\rm O}}, \ \Delta Y = Y_{\rm S} - Y_{{\rm H}_2 {\rm O}} \ {\rm and} \ \Delta P = P_{\rm S} - P_{{\rm H}_2 {\rm O}}$ were used. The solvent electrophilicity was found to be the main factor responsible for changes in the ortho, para and meta polar substituent effects with medium. The variation of the ortho inductive term with the solvent electrophilicity ES was found to be ca threefold smaller than that for para substituents, whereas the ortho resonance term appeared to vary with solvent very similarly to that for para substituents. The steric term of ortho substituents was found to be approximately independent of solvent parameters. The ortho effect caused by the supplementary inductive effect from ortho position was found to disappear in a solvent whose electrophilic solvating power is comparable to that of 60% aqueous ethanol (E ≈ 13.3). Copyright © 2005 John Wiley & Sons, Ltd.
Water‐swollen highly oxygen permeable membranes: Analytical technique and syntheses
Authors: Erdodi G. , Kennedy J. P. 
Published: June 2005

AbstractA generally accepted method for the determination of high oxygen permeabilities (Dk >100 barrers) of water‐immersed membranes is unavailable. We designed and developed a generally applicable method, together with simple equipment, to measure the oxygen permeability up to Dk ∼800 barrers of highly oxygen permeable membranes in contact with water. A theory of the methodology is also presented, giving particular attention to the boundary layer effect and the edge effect. The practical applicability of our technique is demonstrated by preparing and using highly oxygen permeable water‐logged membranes, such as polydimethylsiloxane and polysiloxane copolymers important for medicine. According to our measurements, the Dk's of polydimethylsiloxane, poly(dimethylsiloxane0.80‐co‐diethylsiloxane0.20), and poly(dimethylsiloxane0.84‐co‐diphenylsiloxane0.16) are 792 ± 26, 505 ± 10, and 249 ± 10 barrers, respectively. Evidently, the oxygen permeabilities of polysiloxanes are strongly reduced by substituting the OSiMe2 repeat unit with the structurally similar OSiEt2 and OSiPh2 repeats. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3491–3501, 2005
Advanced flame‐retardant epoxy resins from phosphorus‐containing diol
Authors: Alcón M. José , Ribera Gemma , Galià Marina , Cádiz Virginia 
Published: June 2005

AbstractPhosphorus‐containing epoxy systems were prepared from isobutylbis(hydroxypropyl)phosphine oxide (IHPO) and diglycidyl ether of bisphenol A (DGEBA). Diethyl‐N,N‐bis(2‐hydroxyethyl) aminomethyl phosphonate (Fyrol 6) could not be incorporated into the epoxy backbone by a reaction with either epichlorohydrin or DGEBA because intramolecular cyclization took place. The curing behavior of the IHPO–DGEBA prepolymer with two primary amines was studied, and materials with moderate glass‐transition temperatures were obtained. V‐0 materials were obtained when the resins were tested for ignition resistance with the UL‐94 test. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3510–3515, 2005
Characterization of the improvised explosive urea nitrate using electrospray ionization and atmospheric pressure chemical ionization
Authors: Tamiri Tsippy 
Published: June 2005

AbstractMass spectra of urea nitrate were measured in electrospray ionization and in atmospheric pressure chemical ionization in the negative mode. In both ionization methods two characteristic adduct ions containing the intact molecule [urea nitrate+NO3]− and [urea nitrate+HNO3+NO3]− are shown. The structure of the two adduct ions was deduced using measurements of isotopically labeled urea nitrate. Collision‐induced dissociation measurements of the adduct ions show typical losses enabling the identification of urea nitrate in trace amounts. Using these methods urea nitrate was identified in real cases. Copyright © 2005 John Wiley & Sons, Ltd.
Development of a rapid method for the determination of glimepiride in human plasma using liquid‐liquid extraction based on 96‐well format micro‐tubes and liquid chromatography/tandem mass spectrometry
Authors: Dotsikas Yannis , Kousoulos Constantinos , Tsatsou Georgia , Loukas Yannis L. 
Published: June 2005

AbstractA semi‐automated liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the determination of glimepiride in human plasma. The plasma samples were treated by liquid‐liquid extraction (LLE) in 1.2 mL 96‐well format micro‐tubes. Glimepiride and the internal standard (IS) glibenclamide were extracted from human plasma by LLE, using a mixture of ethyl acetate/diethyl ether 50:50 (v/v) as the organic solvent. After vortexing, centrifugation and freezing, the supernatant organic solvent was evaporated. The analyte and IS were dissolved in a small volume of a reconstitution solution, an aliquot of which was analyzed by reversed‐phase LC/MS/MS with positive ion electrospray ionization, using multiple reaction monitoring. The method proved to be sensitive and specific for both drugs, and statistical evaluation revealed excellent linearity for the range of concentrations 2.0–500.0 ng/mL with very good accuracy and inter‐ and intra‐day precisions. The proposed method enabled the rapid and reliable determination of glimepiride in pharmacokinetic or bioequivalence studies after per os administration of a 3 or 4 mg tablet of glimepiride. Copyright © 2005 John Wiley & Sons, Ltd.
On‐line desalting and determination of morphine, morphine‐3‐glucuronide and morphine‐6‐glucuronide in microdialysis and plasma samples using column switching and liquid chromatography/tandem mass spectrometry
Authors: Bengtsson Jörgen , Jansson Britt , Hammarlund‐Udenaes Margareta 
Published: June 2005

AbstractA sensitive and reproducible method for the determination of morphine and the metabolites morphine‐3‐glucuronide (M3G) and morphine‐6‐glucuronide (M6G) was developed. The method was validated for perfusion fluid used in microdialysis as well as for sheep and human plasma. A C18 guard column was used to desalt the samples before analytical separation on a ZIC HILIC (hydrophilic interaction chromatography) column and detection with tandem mass spectrometry (MS/MS). The mobile phases were 0.05% trifluoroacetic acid (TFA) for desalting and acetonitrile/5 mM ammonium acetate (70:30) for separation. Microdialysis samples (5 µL) were directly injected onto the system. The lower limits of quantification (LLOQ) for morphine, M3G and M6G were 0.50, 0.22 and 0.55 ng/mL, respectively, and the method was linear from LLOQ to 200 ng/mL. For plasma, a volume of 100 µL was precipitated with acetonitrile containing internal standards (deuterated morphine and metabolites). The supernatant was evaporated and reconstituted in 0.05% TFA before the desalting process. The LLOQs for sheep plasma were 2.0 and 3.1 ng/mL and the ranges were 2.0–2000 and 3.1–3100 ng/mL for morphine and M3G, respectively. For human plasma, the LLOQs were 0.78, 1.49 and 0.53 ng/mL and the ranges were 0.78–500, 1.49–1000 and 0.53–500 ng/mL for morphine, M3G and M6G, respectively. Copyright © 2005 John Wiley & Sons, Ltd.
Dissociation of peptide ions by fast atom bombardment in a quadrupole ion trap
Authors: Misharin Alexander S. , Silivra Oleg A. , Kjeldsen Frank , Zubarev Roman A. 
Published: June 2005

AbstractA new technique for fragmentation of cations and anions of peptides stored in ion traps including radiofrequency devices is described. The technique involves irradiation of peptide ions by a beam of particles generated by a fast atom bombardment (FAB) gun. This irradiation leads to fragmentation of NCα backbone bonds (c‐ and z‐fragments) and SS bonds for cations and Cα–C backbone bonds (a‐ and x‐fragments) for anions of peptides. The fragmentation patterns observed are hypothesized to be due to the interaction of peptide ions with metastable, electronically excited species generated by the FAB gun. Interaction of a metastable atom A* with a peptide n‐cation Mn+ leads to the electron transfer from the metastable atom to the polycation through the formation of an ion‐pair collision complex A+. · · · M(n‐1)+. and subsequent fragmentation of the peptide cation. Thus, for polycations, this metastable‐induced dissociation of ions (MIDI) is similar to the phenomenon of electron capture dissociation (ECD). Interaction of A* with an anion leads to the deexcitation of the metastable species and detachment of an electron from the anion. This in turn leads to backbone fragmentation similar to that in electron detachment dissociation (EDD). The MIDI technique is robust and efficient, and it is applicable to peptides in as low charge states as 2+ or 2−. Copyright © 2005 John Wiley & Sons, Ltd.
Comparison of negative and positive ion electrospray ionization mass spectra of calmodulin and its complex with trifluoperazine
Authors: Watt Stephen J. , Oakley Aaron , Sheil Margaret M. , Beck Jennifer L. 
Published: June 2005

AbstractThe protein calmodulin (apoCaM) undergoes a conformational change when it binds calcium. This structure of the protein (Ca4CaM) is a dumbbell‐shaped molecule that undergoes a further profound conformational change on binding of the antipsychotic drug trifluoperazine (TFP). Experimental conditions were developed to prepare samples of apoCaM, Ca4CaM and Ca4CaM/TFP that were substantially free of sodium. The effects of the conformational changes of calmodulin on the charge‐state distributions observed in positive ion and negative ion electrospray ionization (ESI) mass spectra were examined. Conversion of apoCaM into Ca4CaM was concomitant with a change in the negative ion ESI mass spectrum whereby the 16− ion was the most abundant ion observed for the apo form and the 8− ion was the most abundant for the complex. In contrast, in the positive ion ESI mass spectra of apoCaM and Ca4CaM, the most abundant species in each case was the 8+ ion. When a complex of Ca4CaM with TFP was prepared, the most abundant species was the 5+ ion. This is consistent with a conformational change of Ca4CaM that rendered some basic sites inaccessible to ionization in the ESI process. Using the same Ca4CaM/TFP mixture, no complex with TFP was observed in negative ion ESI mass spectra. These observations are discussed in the context of the structural changes that are known to occur in calmodulin, and suggestions are made to explain the apparently conflicting data. The results reported here reflect on the validity of using differences in charge‐state distributions observed in ESI mass spectra to assess conformational changes in proteins. Copyright © 2005 John Wiley & Sons, Ltd.
Structural characterization of flavonol di‐O‐glycosides from Farsetia aegyptia by electrospray ionization and collision‐induced dissociation mass spectrometry
Authors: Shahat Abdelaaty A. , Cuyckens Filip , Wang Wu , Abdel‐Shafeek Khaled A. , Husseiny Husseiny A. , Apers Sandra , Van Miert Sabine , Pieters Luc , Vlietinck Arnold J. , Claeys Magda 
Published: June 2005

AbstractThis study reports the application of mass spectrometric methods to characterize unknown flavonoids of the herb Farsetia aegyptia Turra (Crucifereae). High‐performance liquid chromatography was performed in combination with UV‐photodiode array detection (LC/UV‐DAD) and electrospray ionization mass spectrometry (LC/ESI‐MS) in both positive and negative ion modes. Collision‐induced dissociation (CID) mass spectral data were obtained off‐line by nanospray (nano‐ESI) analysis, which provided a wealth of information and led to the structural proposal of the flavonol di‐O‐glycosides present in the herb extract. In addition to the mass spectral data, we also report NMR data for the major compound which allowed the completion of its structural elucidation. The Farsetia aegyptia Turra herb extract was found to contain three flavonol di‐O‐glycosides containing a monosaccharidic residue linked to the 3‐O position and a disaccharidic residue linked to the 7‐O position; the major compound was characterized as the new flavonoid, isorhamnetin 3‐O‐α‐L‐arabinoside 7‐O‐[β‐D‐glucosyl‐1 → 2]‐αLrhamnoside. Different types of CID spectra, i.e., low‐energy [M+H]+, [M+Na]+ and [MH]− spectra as well as high‐energy [M+Na]+ spectra, were evaluated with respect to their utility to locate the O‐linked saccharidic residues in flavonol di‐O‐glycosides and to determine the sequence in the disaccharidic part. In agreement with previously published data, the 3‐O‐glycosyl residue was more readily lost from the protonated molecule than the 7‐O‐glycosyl residue. The opposite behavior was noted for the fragmentation of the deprotonated and sodiated molecules. Radical ions were observed in the high‐energy [M+Na]+ CID spectra which provided supporting information on the glycosylation positions. Copyright © 2005 John Wiley & Sons, Ltd.
Acetonitrile‐induced unfolding of the photosystem II manganese‐stabilizing protein studied by electrospray mass spectrometry
Authors: Zhang Li , Zhang Feng , Zhang Su‐Yan , Guo Yin‐Long , Xu Chun‐He 
Published: June 2005

AbstractIn this paper an acetonitrile‐induced unfolding of the manganese‐stabilizing protein (MSP) of photosystem II was discovered. More distinct unfolding states of MSP were identified than previously by using mainly electrospray ionization mass spectrometry (ESI‐MS), together with fluorescence spectra and far‐UV circular dichroism (CD) at pH 2.0, 6.2 or 11.6, and with acetonitrile concentrations from 0 to 50%. At pH 6.2 with acetonitrile concentration changing from 0 to 10%, relatively broad charge‐state distributions and poor intensity were observed in ESI‐MS, indicating the presence of coexisting conformers. It was concluded that the structure of the MSP protein is unlikely to be a tightly folded form. When the concentration of acetonitrile was 20–40%, simulating the state in the biological membrane, changes in the state of unfolding of MSP were observed to a certain extent using ESI‐MS, fluorescence and CD spectroscopy. The charge‐state distribution in ESI‐MS was found to move toward high states (from 13+ to 27+ to 15+ to 31+) with increasing acetonitrile concentration. At pH 2.0, the MSP structure is rearranged into an unfolded state, and at pH 11.6 the MSP structure is induced to assume another unordered state by deprotonation of appropriate residues. An interesting observation was that a second peak envelope emerged with 20–50% acetonitrile in the medium at pH 11.6. Copyright © 2005 John Wiley & Sons, Ltd.
Multimodal Treatment of Gastrointestinal Tract Tumors:Consequences for Surgery
Authors: Síewert J. Rüdiger , Stein Hubert J. , von Rahden Burkhard H.A. 
Published: June 2005

AbstractFormerly an exclusive business of surgery, gastrointestinal (GI) tumors are nowadays increasingly approached with multimodal strategies. Neoadjuvant concepts have had a particularly far‐reaching impact on surgery and have contributed to improved survival. Modern pre‐treatment staging and risk assessment provide the basis for decision on one of three general treatment concepts (1) Early cancers, confined to the mucosal/submucosal layers, are approached with primary surgery, without prior antineoplastic therapy. (2) Systemically metastasized tumors receive merely palliative treatment. (3) Locally advanced cancers are increasingly approached with neoadjuvant strategies. The benefit from these preoperative protocols is proven for diverse entities, but is evidently confined to a specific subgroup patients, i.e., the responders to neoadjuvant treatment. These are the ones benefiting most from subsequent surgical resection, which is required to ensure complete removal of the residual tumor tissue, as complete tumor regression occurs very rarely and cannot be proven without a specimen. The fact that responders will benefit and non‐responders will not benefit or will even deteriorate during the neoadjuvant treatment makes early response prediction most demanding. An amazing new approach is the use of position emission tomography with fluro‐desoxyglucose (FDG‐PET) to assess the “metabolic response,” which is possible as early as 14 days after initiation of the neoadjuvant protocol. This strategy offers the chance for modulating the surgical approach in accord i.e., with such metrobolic response termination of the protocol and proceeding to resection in the case of non‐response.The future of GI cancer surgery is multimodal therapy in a response‐based fashion and requires reponse‐based trials for further evaluation.
High Hospital Volume Is Associated with Better Outcomes for Breast Cancer Surgery: Analysis of 233,247 Patients
Authors: Guller Ulrich , Safford Shawn , Pietrobon Ricardo , Heberer Michael , Oertli Daniel , Jain Nitin B. 
Published: June 2005

AbstractBackground:The relationship between hospital volume and outcomes needs to be further elucidated for low‐risk procedures such as surgical therapy of localized breast cancer. The objective of this investigation was to assess the relationship between hospital volume and outcomes for breast cancer surgery.Methods:A total of 233,247 patients who underwent breast‐conserving therapy (BCT) and breast‐ablative therapy (BAT) for localized breast cancer were extracted from 13 years (1988–2000) of the Nationwide Inpatient Samples. Hospital volume was classified as low (<30 cases/year), intermediate (≥ 30 to <70cases/year), and high (≥ 70 cases/year). Multiple linear and logistic regression analyses were used to assess the risk‐adjusted association between hospital volume and outcomes.Results:In risk‐adjusted analyses, patients operated on at low‐volume hospitals were 3.04 (p = 0.03) times more likely to die after BCT compared with patients operated on at high‐volume hospitals. Similarly, low‐volume hospitals had a significantly higher likelihood of postoperative complications (odds ratio [OR] = 1.73, p = 0.01 for BCT; OR = 1.44, p < 0.001 for BAT) compared with high‐volume hospitals. Compared with low‐volume hospitals, length of hospital stay was significantly shorter and nonroutine patient discharge significantly lower for high‐volume providers for both BCT and BAT (all p < 0.001). Patients were also significantly less likely to undergo BCT if operated on in a low‐ or intermediate‐volume hospital compared with a high‐volume provider (p < 0.001).Conclusions:High‐volume hospitals had significantly lower nonroutine patient discharge, postoperative morbidity and mortality, shorter length of hospital stay, and higher likelihood of performing BCT. Referral of patients with localized breast cancer to high‐volume hospitals may be justified.
Psychological risk factors of incidence of breast cancer: a prospective cohort study in Finland
Authors: ARO A. R. , KONING H. J. DE , SCHRECK M. , HENRIKSSON M. , ANTTILA A. , PUKKALA E. 
Published: June 2005

Background. Belief that depression and other psychological factors predict breast cancer is common, but there have been few prospective epidemiological studies on this relationship.Method. The relationship between depression, personality traits, illness attitudes, life events and health history, and breast cancer risk was studied in a prospective, 6–9 year follow-up of a cohort study of 10892 Finnish women of 48–50 years of age at the baseline. Cancer cases were obtained from the Cancer Registry of Finland. Multivariate logistic regression analysis was performed controlling for socioeconomic factors, family history of cancer, parity, and health behaviours.Results. Breast cancer incidence in the cohort was 1·15 times the average in age group 50–59. There was no evidence of depression, trait anxiety, cynical distrust, or coping being significant predictors of breast cancer incidence.Conclusion. In this cohort study with the 6–9 year follow-up, psychological factors such as depression, trait anxiety, cynical distrust, or coping did not increase breast cancer risk.