bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copolymerization of N‐Vinylcarbazole and Vinyl Acetate via Reversible Addition‐Fragmentation Chain Transfer (RAFT) Polymerization
Authors: Zhu Jian , Zhu Xiulin , Cheng Zhenping , Zhang Zhengbiao 
Published: January 2008

AbstractSummary: The reversible addition–fragmentation chain transfer (RAFT) random copolymerization of N‐vinylcarbazole (NVC) and vinyl acetate (VAc) was carried out using s‐benzyl‐o‐ethyl dithiocarbonate (BED) as the chain transfer agent and 2,2′‐azoisobutyronitrile (AIBN) as the initiator in 1,4‐dioxane solution at 70 °C. The polymerization showed the characteristics of ‘living’ free radical polymerization behaviors: first order kinetics, linear relationships between molecular weight and conversion, and narrow polydispersity of the polymers. The reactivity ratios of NVC and VAc were calculated via the Kelen–Tudos (KT) and non‐linear error in variable (EVM) methods and showed as r1 = 1.938 ± 0.191, r2 = 0.116 ± 0.106. The thermal behavior of the copolymers with different content of NVC and VAc was investigated by DSC and TGA. The results showed that the introduction of a VAc segment into copolymer significantly reduced the Tg of the NVC homopolymers. FT‐IR spectra, fluorescence spectra, and cyclic voltammetric behavior of these copolymers were also measured and compared with those of NVC homopolymers. The copolymers showed similar oxidative behavior to the NVC homopolymer. However, there was only one reductive potential peak shown for the copolymers at about 0.058 V.
Characterization of Polymer Architectures by Multidetection Size Exclusion Chromatography
Authors: Puskas Judit E. , Foreman Elizabeth A. , Dos Santos Lucas M. , Soytaş Serap Hayat 
Published: January 2008

AbstractSummary: This paper discusses the analysis of star‐branched and dendritic polyisobutylenes (PIBs) using branching parameters based on radii of gyration Rg,z and hydrodynamic radii Rh,z. Rg,z and Rh,z were measured by Size Exclusion Chromatography equipped with a Wyatt Technology Viscostar viscometer (VIS), a Wyatt Optilab DSP RI detector, a Wyatt DAWN EOS 18 angle Multiangle Light Scattering (MALS) detector and a Wyatt Quasi‐elastic Light Scattering QELS detector. Branching parameters were calculated from these measurements and compared with those computed for these architectures.
Approximation of the Navier–Stokes system with variable viscosity by a system of Cauchy–Kowaleska type
Authors: de Araújo G. M. , de Menezes S. B. , Gúzman R. B. 
Published: January 2008

AbstractIn this paper, we study the existence of weak solutions when n⩽4 of the mixed problem for the Navier–Stokes equations defined in a bounded domain Q using approximation by a system of Cauchy–Kowaleska type. Periodical solutions are also analyzed. Copyright © 2008 John Wiley & Sons, Ltd.
1H NMR spectroscopy of ascitic fluid: discrimination between malignant and benign ascites and comparison of the results with conventional methods
Authors: Bala Lakshmi , Sharma Abhinav , Yellapa Radha Krishna , Roy Raja , Choudhuri G. , Khetrapal C. L. 
Published: January 2008

AbstractIt is often difficult to distinguish benign ascites from malignant ascites by conventional examination of ascitic fluid. Therefore, 1H NMR spectroscopy of ascitic fluid specimens was explored as a one‐shot experiment to identify potentially interesting metabolic indices that might help to differentiate between the two. Seventy ascitic fluid specimens (15 cytologically positive for malignant cells, eight cytologically negative for malignant cells but remaining suspicious for malignant ascites, and 47 due to liver cirrhosis) were subjected to 1H NMR spectroscopy for quantitative estimation of 14 metabolites. Mean concentrations of the metabolites were compared with the Mann–Whitney U test. Multivariate discriminant function analysis was performed to determine important descriptors in the discrimination process. The sensitivity and specificity of the proposed model were compared with conventional methods using ascitic fluid protein and serum ascitic albumin gradient. Then, probable predictions for the doubtful cases were made using the proposed model. Patients with malignant ascites had significantly higher mean concentrations (µM) of β‐hydroxybutyrate (594 vs 61), lactate (5384 vs 2104), acetone (136 vs 69), and acetoacetate (122 vs 48) than patients with cirrhotic ascites, and significantly lower concentrations of glutamine (359 vs 615), citrate (62 vs 118), glucose (4933 vs 8411), tyrosine (44 vs 124), and phenylalanine (51 vs 93) (P < 0.05 for all). In the discriminant function analysis model, the best discrimination (P < 0.001) was achieved when β‐hydroxybutyrate, lactate, citrate and tyrosine were considered together as markers. Sensitivity and specificity of the proposed model, ascitic fluid protein and serum ascitic albumin gradient were found to be 100% and 97.9%, 53.3% and 76.6%, and 60% and 87.2%, respectively. The proposed model put five of the eight doubtful cases in the malignant group. This is encouraging and may provide useful information for clinical purposes. Copyright © 2008 John Wiley & Sons, Ltd.
A general solution to the identification of moving vehicle forces on a bridge
Authors: González A. , Rowley C. , OBrien E. J. 
Published: January 2008

AbstractBridge weigh‐in‐motion systems measure bridge strain caused by the passing of a truck to estimate static axle weights. For this calculation, they commonly use a static algorithm that takes the bridge influence line as reference. Such a technique relies on adequate filtering to remove bridge dynamics and noise. However, filtering can lead to the loss of a significant component of the underlying signal in bridges where the vibration does not have time to complete sufficient number of cycles and in cases of closely spaced axles traveling at high vehicle speeds. In order to overcome these limitations and also to provide additional information on the dynamics of the applied forces, this paper presents an algorithm based on first‐order Tikhonov regularization and dynamic programming. First, strain measurements are simulated using an elaborate three‐dimensional vehicle and orthotropic bridge interaction system. Then, strain is contaminated with noise and input into the moving force identification algorithm. The procedure to implement the algorithm and to derive the applied forces from the simulated strain record is described. Vehicle axle forces are shown to be accurately predicted for smooth and rough road profiles and a range of speeds. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of collision‐activated dissociation gas and collision energy on the fragmentation of dipyridamole and its rapid and sensitive liquid chromatography/electrospray ionization tandem mass spectrometric determination in human plasma
Authors: Yadav Manish , Patel Dharmesh , Singhal Puran , Prasad Rajendra , Goswami Sailendra , Shrivastav Pranav S. , Pande Umesh C. 
Published: January 2008

AbstractThe effect of nitrogen as the collision‐activated dissociation (CAD) gas on the fragmentation of dipyridamole was investigated in the range of 10–90 eV collision energy. The results support the collision model reported elsewhere, that the degree of ion fragmentation increases with the increasing mass of the collision gas. A simple, sensitive and high‐throughput liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed for the determination of dipyridamole, a platelet aggregation inhibitor in human plasma, using granisetron as internal standard (IS). The method involved liquid–liquid extraction of the analyte and IS from 0.5 mL human plasma with diethyl ether. The chromatographic separation was achieved under isocratic conditions and the ion transitions for dipyridamole (m/z 505.40 → 429.60) and the IS (m/z 313.10 → 138.20) were monitored on a triple quadrupole mass spectrometer, operating in positive ion multiple reaction monitoring (MRM) mode. The method was validated over the concentration range 5.1–4499.1 ng/mL for dipyridamole. The method was rugged and rapid with a total run time of 1.2 min. It was successfully applied to a pivotal bioequivalence study in 67 healthy human subjects after oral administration of a 75 mg extended release formulation under fasting condition. Copyright © 2008 John Wiley & Sons, Ltd.
The interaction of human serum albumin with titanium studied by means of atomic force microscopy
Authors: Van De Keere Isabel , Willaert Ronnie , Tourwé Els , Hubin Annick , Vereecken Jean 
Published: January 2008

AbstractTitanium is frequently used as a biomaterial for implants in orthopaedics and cardiovascular devices. Understanding the biocompatibility, which is strongly influenced by the adsorption of proteins onto the surface, is very important to improve implants. The surface chemistry of an implant material and its influence on the interaction with body fluid is crucial in that perspective. The main goal of this study was to investigate the conformation of human serum albumin (HSA) with commercially pure titanium (CP Ti) on a molecular level. Both ex situ and in situ AFM imaging showed the conformation of HSA on CP Ti and on mica, which was used as a reference material. Single molecules and aggregates of albumin were observed. HSA can be recognised by the globular shape. The conformation of the adsorbed HSA molecules was different on titanium and mica, for both the ex situ and in situ imaging. The difference in wettability between both substrates caused a larger spread of the protein on the CP Ti surface and thus resulted in a larger perturbation of the native structure of HSA as compared to mica. Copyright © 2008 John Wiley & Sons, Ltd.
Electroless deposition of polyaniline: synthesis and characterization
Authors: Attout A. , Yunus S. , Bertrand P. 
Published: January 2008

AbstractPolyaniline (PANi), as conductive polymer, constitutes an attractive material for electronic and optical applications. Different from electropolymerization and chemical oxidative polymerization, electroless deposition is another method for synthesizing PANi. Aniline can polymerize slowly and spontaneously on platinum or palladium surface in an aqueous acid solution of the monomer. This reaction proceeds via an electrochemical mechanism that involves the reduction of dissolved oxygen as cathodic and oxidation of aniline as anodic half‐reactions at the metal/solution interface. PANi, obtained by electroless synthesis, was compared to chemical oxidative and electropolymerized ones by XPS and SEM. The product of electroless deposition is found to be chemically similar to the others but its morphology is different. The PANi film growth and morphology are studied as a function of time and temperature. Copyright © 2008 John Wiley & Sons, Ltd.
Pyrite oxidation in acidic medium: overall reaction pathway
Authors: Demoisson Frédéric , Mullet Martine , Humbert Bernard 
Published: January 2008

AbstractThis study investigated the oxidation processes of pyrite by dissolved oxygen. Synthetic pyrite suspensions have reacted with dissolved oxygen in a closed‐thermostated system for 20 h and at pH values of 2.0 and 3.5. Special emphasis was made on the characterization of the solid phase formed during the reaction process, using X‐ray photoelectron spectroscopy (XPS) and confocal Raman microspectrometry. The results revealed a strong heterogeneity of the samples with the identification of two different micrometric areas. Eg and Ag Raman pyrite modes were characterized by wavenumber drifts, from 0 to 6, correlated with the shine changes of the micrometric probed area. XPS analyses provided evidence of the distribution of iron and sulfur species at the reacted pyrite surface. The Fe(2p3/2) signals showed an increase in the binding energy range typical of Fe(III)S and Fe(III)O compounds. The S(2p) XPS signals included contribution from disulfide, monosulfide, elemental sulfur, and sulfate. Elemental sulfur should be protected from sublimation under ultrahigh vacuum, possibly by an overlaying of other species such as Fe(III) (oxyhydr)oxide species. An overall reaction pathway of the pyrite in oxidizing (Cr(VI), dissolved oxygen, Fe(III)), and acidic media (pH ⩽3.5) has been established from the present results and previous papers. Copyright © 2008 John Wiley & Sons, Ltd.
Immobilization stress suppresses cutaneous delayed‐type hypersensitivity reaction induced by gastrointestinal sensitization in mice: association with Langerhans cell of the forestomach
Authors: Tamiya Hisashi , Kobayashi Hiromi , Yamanaka Kazuhoshi , Fujita Naoko , Tsuruta Daisuke , Mizuno Nobuyuki , Ishii Masamitsu 
Published: January 2008

AbstractPsychological stress (PS) has various influences on allergic diseases. Although gastrointestinal sensitization induces hypersensitivity reactions in the skin, such as urticaria and dermatitis, due to food or drug allergy, the effect of PS on the gastrointestinal sensitization phase remains unclear. We administered 2,4,6‐trinitrochlorobenzene (TNCB) to BALB/c mice intragastrically (gastrointestinal sensitization). After 4 days, we elicited a cutaneous delayed‐type hypersensitivity (DTH) reaction by applying TNCB to the ear. We examined the effects of immobilization stress (IS) before gastrointestinal sensitization and elicitation on the cutaneous DTH (CDTH) by measurement of the thickness of the swollen ear, morphological changes and the number of Ia molecule‐positive Langerhans cells (Ia + LC) in the forestomach, and serum corticosterone (CORT) concentration. In addition, we studied the effect of pre‐administration of a glucocorticoid receptor antagonist (RU486). CDTH was suppressed significantly with application of IS for more than 6 h prior to gastrointestinal sensitization. Simultaneously, Ia + LC became smaller and round in shape and decreased in number. The serum CORT concentration doubled following IS for more than 2 h, and these changes were suppressed by pre‐administration of RU486. The results indicate that IS suppresses gastrointestinal sensitization, probably in association with suppression of the antigen‐presenting function of the Ia + LC by elevation of steroid hormones. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis, Crystal Structure and Characterization of Hexakis[2‐methoxy‐4‐formylphenoxy]cyclotriphosphazene
Authors: Tümer Yasemin , Bati Hümeyra , Çalişkan Nezihe , Yüksektepe Çi˘dem , Büyükgüngör Orhan 
Published: January 2008

AbstractThe new cyclotriphosphazene derivative N3P3(OC6H3OCH3COH)6 (1) was synthesized from hexachlorocyclotriphosphazene, N3P3Cl6, and 4‐hydroxy‐3‐methoxybenzaldehyde in acetonitrile in the presence of K2CO3. The structure of 1 was verified by means of elemental analysis, IR, 1H NMR, 13C NMR, 31P NMR spectra, thermal analysis and X‐ray diffraction.
A New Supramolecular Assembly Formed by Melamine and Sulfuric Acid
Authors: Heine Axel , Gloe Kerstin , Doert Thomas , Gloe Karsten 
Published: January 2008

AbstractPolymeric melaminium sulfate [(LH2)2(SO4)2]n has been synthesized by reaction of melamine L with sulfuric acid in aqueous solution. The compound was characterized by elemental analysis, 1H NMR, ESI MS and a single crystal X‐ray diffraction analysis. The architecture of the assembly formed is based on hydrogen bonded dimers of diprotonated melaminium cations (LH2)2+ which are linked by a hydrogen bonded network with sulfate ions forming 2D sheets. A 3D polymeric structure results from the presence of mutual hydrogen bonds between sulfate ions and melaminium cations in different sheets. Significant π‐π stacking is also present between the aromatic cations in this supramolecular arrangement.
Hydrated Zinc p‐Aminobenzoate [Zn(p‐H2NC6H4COO)2(H2O)]·H2O from a Layered Zinc Hydroxide
Authors: v. Prondzinski Nina , Merz Klaus 
Published: January 2008

AbstractA new pillard crystal packing of a hydrated [Zn(PABA)2(H2O)]·H2O (PABA = p‐aminobenzoate) (1) was obtained starting from a layered zinc hydroxide with PABA as organic substrate. Compound 1 was characterized in the solid state by crystal structure analysis and in solution by 13C‐ and 1H‐NMR spectroscopy. In contrast to the known hydrate of [Zn(PABA)2]·1.5H2O the water molecules of crystal packing of 1 are involved in the coordination sphere of the zinc atoms, forming hydrogen bonding interactions between amino groups of PABA and water molecules.
Synthesis and Crystal Structures of Two New Layered Manganese(II) Diphosphonates: Mn2[{(O3PCH2)2NHR}(H2O)F]·H2O
Authors: Meng Lei , Li Jing , Sun Zhen‐Gang , Zheng Xue‐fang , Dong Da‐Peng , Chen Hui , Zhu Yan‐Yu , Zhao Yan , Zhang Jing 
Published: January 2008

AbstractTwo manganese phosphonates Mn2[{(O3PCH2)2NHR}(H2O)F]·H2O (R = −C6H11 (1), −CH2C5H4N (2)) have been synthesized by hydrothermal reaction and characterized by single–crystal X–ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The two isomorphous compounds feature layered structures in ab plane, in which the tetramers comprised of two MnO4F2 and two MnO5F polyhedra are cross–linked via phosphonate oxygen atoms to form MnII phosphonate layers. The organic groups of the ligands are orientated toward the interlayer space.
Disparities in Surgical Care: Strategies for Enhancing Provider–Patient Communication
Authors: Bigby JudyAnn , Ashley Stanley W. 
Published: January 2008

AbstractPatient–provider communication is critical to eliminating disparities in healthcare. Both the patient and the physician bring a variety of assumptions to the therapeutic partnership. As illustrated in a surgical case, these are based not only on race and ethnicity but also on a host of other factors, which may affect both partners’ perceptions of reality and their subsequent behavior. Communication is an essential component of quality and is necessary to improve patients’ understanding of the content of their care, their ability to make informed choices, and their ability to adhere to recommended therapies. There are a variety of practical strategies to enhance awareness of these issues and improve communication that we need to begin to incorporate into surgical culture.
Impact of Adenoma Weight and Ectopic Location of Parathyroid Adenoma on Localization Study Results
Authors: Erbil Yeşim , Barbaros Umut , Tükenmez Mustafa , İşsever Halim , Salmaslıoğlu Artür , Adalet Işık , Özarmağan Selçuk , Tezelman Serdar 
Published: January 2008

AbstractAlthough the sensitivity of preoperative localization techniques is high for solitary parathyroid adenomas, negative imaging study results are inevitable. The weight and location of the parathyroid adenoma may contribute to the negative results. We aimed to study the impact of adenoma weight and ectopic location of the parathyroid adenoma on ultrasonography and sestamibi scan results.
The patients were divided into two groups according to adenoma location. Group 1 consisted of 36 patients with ectopic location, and group 2 consisted of 149 patients with normal location. Parathyroid adenoma weight and the results of imaging studies were determined in all patients.
Of 185 patients operated on for hyperparathyroidism, 36 (19.4%) had ectopic parathyroid glands. There was a positive correlation between adenoma weight and positive imaging studies, whereas ectopic location did not correlate with negative imaging study results. There was no significant difference between the ectopic adenoma ratio of patients with negative and positive imaging study results. The weight of the ectopic parathyroid adenoma was significantly lower in patients with negative imaging study results than in patients with positive imaging study results (p = 0.001). According to the analysis of variance, patients with higher‐weight adenomas have positive imaging study results irrespective of ectopic location.
For both normal and ectopic adenoma locations, adenoma weight was found only to be a factor that positively influences imaging study results.
Amniotic fluid iodine concentrations do not vary in pregnant women with varying iodine intake
Authors: García-Fuentes Eduardo , Gallo Manuel , García Laureano , Prieto Stephanie , Alcaide-Torres Javier , Santiago Piedad , Velasco Inés , Soriguer Federico 
Published: January 2008

Iodine deficiency is an important clinical and public health problem. Its prevention begins with an adequate intake of iodine during pregnancy. International agencies recommend at least 200 μg iodine per d for pregnant women. We assessed whether iodine concentrations in the amniotic fluid of healthy pregnant women are independent of iodine intake. This cross-sectional, non-interventional study included 365 consecutive women who underwent amniocentesis to determine the fetal karyotype. The amniocentesis was performed with abdominal antisepsis using chlorhexidine. The iodine concentration was measured in urine and amniotic fluid. The study variables were the intake of iodized salt and multivitamin supplements or the prescription of a KI supplement. The mean level of urinary iodine was 139·0 (sd94·5) μg/l and of amniotic fluid 15·81 (sd7·09) μg/l. The women who consumed iodized salt and those who took a KI supplement had significantly higher levels of urinary iodine than those who did not (P = 0·01 andP = 0·004, respectively). The urinary iodine levels were not significantly different in the women who took a multivitamin supplement compared with those who did not take this supplement, independently of iodine concentration or multivitamin supplement. The concentrations of iodine in the amniotic fluid were similar, independent of the dietary iodine intake. Urine and amniotic fluid iodine concentrations were weakly correlated, although the amniotic fluid values were no higher in those women taking a KI supplement. KI prescription at recommended doses increases the iodine levels in the mother without influencing the iodine levels in the amniotic fluid.
Memory and metamemory in schizophrenia: a liberal acceptance account of psychosis
Authors: Moritz S. , Woodward T. S. , Jelinek L. , Klinge R. 
Published: January 2008

BackgroundIn previous studies we suggested that liberal acceptance (LA) represents a fundamental cognitive bias in schizophrenia and may explain why patients are more willing to accept weak response alternatives and display overconfidence in incorrect responses. The aim of the present study was to test a central assumption of the LA account: false alarms in schizophrenia should be particularly increased when the distractor–target resemblance is weak relative to a control group.MethodSixty-eight schizophrenia patients were compared to 25 healthy controls on a visual memory task. At encoding, participants studied eight complex displays, each consisting of a unique pairing of four stimulus attributes: symbol, shape, position and colour. At recognition, studied items were presented along with distractors that resembled the targets to varying degrees (i.e. the match between distractors and targets ranged from one to three attributes). Participants were required to make old/new judgements graded for confidence.ResultsThe hypotheses were confirmed: false recognition was increased for patients compared to controls for weakly and moderately related distractors only, whereas strong lure items induced similar levels of false recognition for both groups. In accordance with prior research, patients displayed a significantly reduced confidence gap and enhanced knowledge corruption compared to controls. Finally, higher neuroleptic dosage was related to a decreased number of high-confident ratings.ConclusionsThese data assert that LA is a core mechanism contributing to both enhanced acceptance of weakly supported response alternatives and metamemory deficits, and this may be linked to the emergence of positive symptomatology.