bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prolonged QT interval in pediatric sickle cell disease
Authors: Mueller Brigitta U. , Martin Kahlil J. , Dreyer William , Bezold Louis I. , Mahoney Donald H. 
Published: August 2005

AbstractWe recently cared for a patient with sickle cell disease (SCD) who presented with cardiac arrest and was found to have a prolonged corrected QT interval (QTc). This prompted us to perform a retrospective review of all electrocardiograms performed in patients with SCD during the last two years. Among 142 patients with ECG results, we identified 12 patients (8 males and 4 females), who had one or more documented measurements of prolonged QTc intervals. The relatively high prevalence of borderline or moderately prolonged QTc intervals in our patient population warrants further investigation. Pediatric Blood Cancer 2006;47:831–833. © 2005 Wiley‐Liss, Inc.
Utility of electrophoretically derived protein mass estimates as additional constraints in proteome analysis of human serum based on MS/MS analysis
Authors: Kim Jin Young , Lee Jeong Hwa , Park Gun Wook , Cho Kun , Kwon Kyung‐Hoon , Park Young Mok , Cho Sang Yun , Paik Young‐Ki , Yoo Jong Shin 
Published: July 2005

AbstractThe proteome of a HUPO human serum reference sample was analyzed using multidimensional separation techniques at both the protein and the peptide levels. To eliminate false‐positive identifications from the search results, we employed a data filtering method using molecular weight (MW) correlations derived from denaturing 1‐DE. First, the six most abundant serum proteins were removed from the sample using immunoaffinity chromatography. 1‐DE was then used to fractionate the remaining serum proteins according to the MW. Gel bands were isolated and in‐gel digested with trypsin, and the resulting peptides were analyzed by 2‐D LC/ESI‐MS/MS. A SEQUEST search using the MS/MS results identified 494 proteins. Of these, 202 were excluded formally using protein data filtering as they were single‐assignment proteins and their theoretical and electrophoretically‐derived MWs did not correlate at high confidence. To evaluate this method, the results were compared with those of 1‐D LC/MALDI‐TOF/TOF and HUPO Plasma Proteome Project analyses. Our data filtering approach proved valuable in analysis of complex, large‐scale proteomes such as human serum.
Novel active ester‐bridged copolynorbornene materials containing terminal functional hydroxyl, amino, methacryloyl, or ammonium groups via ring‐opening metathesis polymerization
Authors: Liaw Der‐Jang , Chen Tsang‐Pin , Huang Ching‐Cheng 
Published: August 2005

AbstractSeveral random and block copolynorbornenes with side chains containing terminal hydroxyl, amino, methacryloyl or ammonium groups were derived from the functional alkyl ester‐containing norbornenes by ring‐opening metathesis polymerization (ROMP). The main chain of ROMP‐type polynorbornene had a more important role for glass‐transition temperature in comparison with vinyl addition polymerization. There is little effect on glass‐transition temperature (about −39 °C) of polynorbornenes with different length of alkyl side chain. The organosoluble copolynorbornenes with active crosslinkable methylacryloyl side chains derived from functional hydroxyl group were prepared to improve the thermal stability of poly(methyl methacrylate) [decomposition temperature (Td)10% = 325 °C in nitrogen] by forming networked AB crosslinked polymer (T = 367 °C in nitrogen). The sizes of nanometer‐scale polymeric micelles of block copolymers having hydrophobic alkyl ester and hydrophilic ammonium groups were measured in the range of 11–25 nm by scanning electron microscopy. These polymeric materials with various functional groups or amphiphilic architectures are accessible by ROMP, whose topology makes them particularly attractive for application potential such as biomedical and photoelectric materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4233–4247, 2005
Ethylene and propylene polymerization with bis(indenyl)zirconium/Mao catalytic systems modified by sterically demanding alcohols
Authors: Firme Caio L. , Grafov Andrei V. , Dias Marcos L. 
Published: August 2005

AbstractEthylene and propylene polymerization using Ind2ZrCl2 and Ind2Zr(CH3)2/MAO catalytic systems modified by the sterically demanding bridged alicyclic alcohols, adamantan‐1‐ol, adamantan‐2‐ol, 2‐methyladamantan‐2‐ol, and fenchyl alcohol, was investigated. Lower alcohols like isopropanol completely deactivate the system, whereas in the case of catalysts modified by these voluminous alcohols only a slight decrease in the catalytic activity proportional to alcohol/metallocene molar ratio was observed. The addition of the modifiers gives rise to polymers with higher molecular weights than the nonmodified systems, but no structural changes in the polyethylenes were observed. The addition of the sterically demanding alcohols to the reaction medium changes the regioregularity of polypropylenes, but does not significantly influence their stereoregularity, at 30 °C. Propylene–ethylene copolymers containing up to 8.6% of ethylene units derived from 1,3‐insertion and significant amount of rr‐centered pentads were obtained by single‐monomer polymerization of propylene with Ind2ZrCl2/MMAO/adamantan‐1‐ol, at 70 °C. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4248–4259, 2005
A modified UNIFAC model for the prediction of phase equilibrium for polymer solutions
Authors: Liu Qing Lin , Cheng Zhen Feng 
Published: July 2005

AbstractA new simple activity coefficient model for the prediction of solvent activities in polymer solutions is presented. The model consists of three terms, the combinatorial and the residual terms, which are taken from UNIFAC model, and a free‐volume term derived from the van der Waals partition function with the mixed volume, the mixed free‐volume and the mixed c‐value being supposed to be given by linear mixing rules. Twenty‐one polymer solution systems were used to test the applicability of the present model. Compared with the UNIFAC‐FV, Entropic‐FV, and Entropic‐FV‐1.2 models, it is found that the model proposed in this work can produce better results than those from the other three models. Furthermore, the model is valid for a broad range of polymer concentration and a wide range of temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2541–2547, 2005
Rheology of concentrated blends with immiscible components
Authors: Yu Wei , Zhou Chixing , Xu Yuanze 
Published: July 2005

AbstractThe rheology and morphology evolution of nondilute and concentrated immiscible blends were investigated in this paper. A theoretical model was established by a Hamiltonian formalism. The interactions between droplets were integrated in the morphology‐dependent drag coefficient. The phenomenological parameters in the model were determined by the comparisons with the dilute emulsion model and the Krieger–Dougherty model. The model showed better predictions in the shear viscosity and first normal stress difference than that of the dilute emulsion model. The effects of volume fraction on droplet deformation were also predicted and compared with the numerical simulations. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2534–2540, 2005
Rheological characterization and microphase‐separated structure of a poly(ether‐block‐amide) segmented block copolymer
Authors: Yang I‐Kuan , Tsai Ping‐Hung 
Published: July 2005

AbstractMelt of a segmented block copolymer having poly(lauryl lactam) as the hard segment and poly(tetramethylene oxide) as the soft segment was investigated by rheological techniques. Storage modulus of the polymer melt exhibits the nonterminal behavior resembling those of diblock and triblock copolymer melts, indicating the existence of a microphase‐separated structure. Contrary to block copolymers, the melt of the segmented block copolymer changes from a weak structure to a stiff one upon raising temperature. The storage modulus of the weak structure at low temperatures is inert to large‐amplitude oscillatory shear, while the oscillatory shear destroys the stiff structure at high temperatures and reduces its storage modulus to a value that is same as that of the weak structure. The tapping‐mode data of atomic force microscopy reveal that at low temperatures the polymer melt exhibits a biphasic structure consisted of small spherical soft domains dispersed in a slightly harder matrix; and at high temperatures the spherical domain structure preserves, though the domain coarsens and the hardness difference between the domain and the matrix enlarges. Infrared spectrum analysis shows that the temperature‐induced structural change is related to the dissociation of hydrogen bonding between the hard and soft segments. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2557–2567, 2005
Coupling between conformation and proton binding in proteins
Authors: Vila Jorge A. , Ripoll Daniel R. , Arnautova Yelena A. , Vorobjev Yury N. , Scheraga Harold A. 
Published: August 2005

AbstractInterest centers here on whether the use of a fixed charge distribution of a protein solute, or a treatment that considers proton‐binding equilibria by solving the Poisson equation, is a better approach to discriminate native from non‐native conformations of proteins. In this analysis of the charge distribution of 7 proteins, we estimate the solvation free energy contribution to the total free energy by exploring the 2ζ possible ionization states of the whole molecule, with ζ being the number of ionizable groups in the amino acid sequence, for every conformation in the ensembles of 7 proteins. As an additional consideration of the role of electrostatic interactions in determining the charge distribution of native folds, we carried out a comparison of alternative charge assignment models for the ionizable residues in a set of 21 native‐like proteins. The results of this work indicate that (1) for 6 out of 7 proteins, estimation of solvent polarization based on the Generalized Born model with a fixed charge distribution provides the optimal trade‐off between accuracy, with respect to the Poisson equation, and speed when compared to the accessible surface area model; for the seventh protein, consideration of all possible ionization states of the whole molecule appears to be crucial to discriminate the native from non‐native conformations; (2) significant differences in the degree of ionization and hence the charge distribution for native folds are found between the different charge models examined; (3) the stability of the native state is determined by a delicate balance of all the energy components, and (4) conformational entropy, and hence the dynamics of folding, may play a crucial role for a successful ab initio protein folding prediction. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Electrochemical detection of indoles at diamond electrodes
Authors: Foord John S. , Chatterjee Arnab 
Published: July 2005

AbstractIndoles represent an important class of chemical compounds, of biological significance, and various attempts have been made to develop electrochemical sensors for their detection. In general, this has failed because of the electrode fouling which tends to occur when conventional electrode materials are employed, so we have explored the use of diamond electrodes, in view of their known resistance to electrode poisoning. High phase purity boron‐doped diamond electrodes show no detectable oxidative signal when used in solutions containing indole‐3‐methanol or 1‐methyl indole. However, indole oxidation at electrode potentials greater than 0.7 V vs. SCE is seen if lower purity diamond or nanodiamond electrodes are employed. Electrode fouling is found to be problematic, but significantly better than at pyrolytic graphite electrodes. The oxidation of tryptophan at high phase purity diamond electrodes is seen, indicating that in general the indole oxidation chemistry is dependent both on the type of diamond electrode used, and the particular indole involved. Sensitive detection of tryptophan at micromolar concentrations is observed without electrode fouling, although electrode passivation is seen in concentrated tryptophan solutions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Methyl radical beam sources for ultra high vacuum applications
Authors: Gehin T. , Wallart X. , Vignaud D. 
Published: July 2005

AbstractMethyl radical beam sources for ultra high vacuum applications have been characterised using ionisation threshold mass spectrometry. Methane, ethane and acetone have been dissociated in a resistively heated carbon gas cracker cell. The effect of pressure on the methyl radicals formation has been studied independently of the precursor gas flow by changing the cell conductance. Methyl radical fluxes heavily depend on the pressure and the nature of precursor, ranging from 1 × 1015 cm–2 s–1 for a methane flow of 1 sccm up to 2 × 1016 cm–2 s–1 when acetone is used. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of vacancy related defects in diamond
Authors: Hounsome L. S. , Jones R. , Martineau P. M. , Shaw M. J. , Briddon P. R. , Öberg S. , Blumenau A. T. , Fujita N. 
Published: July 2005

Abstract〈110〉 vacancy chains, multi‐vacancy clusters and vacancy discs have been modeled using density functional theory within the AIMPRO and DFTB codes. While a connection can be established between the results on vacancy chains and previous EPR experiments, no connection can be made between the point defects and the optical properties of natural type IIa brown diamonds. However, a vacancy disc consisting of a {111} double plane of vacancies is stable and possesses an absorption spectrum similar to that found in brown diamonds. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrochemical characterization of intrinsic hydrogen terminated single crystalline CVD diamond
Authors: Shin D. , Watanabe H. , Nebel C. E. 
Published: July 2005

AbstractCyclic voltammetry experiments have been performed on high quality intrinsic hydrogen terminated single crystalline CVD diamond to characterize the electron transfer at the interface of the diamond/redox‐electrolyte system. In vacuum these diamond films are insulating, but immersed into electrolyte solutions which contain Fe(CN)63–/4– or Ru(NH3)62+/3+ generates insulator–metal transition. The two redox systems have chemical potentials below the valence‐band maximum EVBM as calculated from the formal potentials. The same experiments applied with methyl viologen (MV) as redox couple results in no detectable electron exchange. MV has two levels, but both are above EVBM. The reversible electron exchange with Fe(CN)63–/4– or Ru(NH3)62+/3+ is rate limited, as peaks are broadened and shifted to higher and lower potentials. The results are compared with data available in the literature for high quality H‐terminated boron doped (metallic) polycrystalline diamond which shows that the formal potentials are basically comparable. Electrochemical oxidation terminates the experiments as the surface conductivity is removed and films become highly resistive. The results are discussed using the transfer‐doping and the Marcus‐Gerischer models for interpretation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Peculiarities of thermopower in Bi microwires at low temperatures
Authors: Gitsu D. , Huber T. , Konopko L. , Nikolaeva A. 
Published: July 2005

AbstractThe temperature dependence (4.2–300 K) of the thermopower of thin Bi wires was investigated. The cylindrical Bi crystals ranging in size from 0.19 to 3 µm were prepared by high‐frequency liquid‐phase casting in a glass capillary. The nanowires are single crystal and are oriented with the (1011) crystalline axis along the wire axis. For temperatures below ∼12 K the thermopower is dominated by phonon drag and a maximum is observed at around 6 K. The position of this maximum and its value depends on the wire's diameter and the length of the samples. In the temperature range 8–11 K the phonon‐drag contribution follows an exponential temperature dependence that is characteristic of a two‐stage mechanism. The positive thermopower maxima of the order of 10 µV K–1 are explained in terms of the phonon drag of carriers. Several mechanisms that may account for the data are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sequence determination in aliphatic poly(ester amide)s by matrix‐assisted laser desorption/ionization time‐of‐flight and time‐of‐flight/time‐of‐flight tandem mass spectrometry
Authors: Rizzarelli Paola , Puglisi Concetto , Montaudo Giorgio 
Published: August 2005

AbstractPoly(ester amide)s from dimethyl sebacate or sebacic acid and 2‐aminoethanol or 4‐amino‐1‐butanol were characterized by post‐source decay matrix‐assisted laser desorption/ionization time‐of‐flight (PSD‐MALDI‐TOF) and time‐of‐flight/time‐of‐flight tandem mass spectrometry (MALDI‐TOF/TOF‐MS/MS). Sodiated oligomers were selected as precursor ions for dissociation studies. PSD analysis was performed on dimethyl sebacate, dicarboxylic, carboxylic and amino alcohol, and diamino alcohol terminated oligomers. PSD‐MALDI‐TOF mass spectra yielded information on the fragmentation mechanisms of the poly(ester amide) chains, showing that the main cleavages proceed through a β‐hydrogen transfer rearrangement. MALDI‐TOF/TOF‐MS/MS provided structural information concerning ester/amide sequences in the polymer chains. As expected, together with the ions appearing in the PSD‐MALDI mass spectrum, several new abundant fragment ions in the low‐mass range are present in MALDI‐TOF/TOF‐MS/MS spectra. These new product ions proved to be diagnostic and made it possible to establish the presence of random sequences of ester and amide bonds in the poly(ester amide)s samples. Copyright © 2005 John Wiley & Sons, Ltd.
‘De novo’ sequencing of Atlantic cod vitellogenin tryptic peptides by matrix‐assisted laser desorption/ionization quadrupole time‐of‐flight tandem mass spectrometry: similarities with haddock vitellogenin
Authors: Cohen Alejandro M. , Mansour Atef A. H. , Banoub Joseph H. 
Published: July 2005

AbstractVitellogenin is a protein produced by the liver of oviparous animals in response to circulating estrogens. The amino acid sequence of vitellogenin from Atlantic cod (Gadus morhua) has not yet been determined. In this study Atlantic cod vitellogenin was characterized using a ‘bottom‐up’ mass spectrometric approach. Vitellogenin synthesis was induced ‘in vivo’ with β‐estradiol, and subjected to trypsin digestion for characterization by matrix‐assisted laser desorption/ionization quadrupole time‐of‐flight tandem mass spectrometry. A peptide mass fingerprint was obtained and ‘de novo’ sequencing of the most abundant tryptic peptides was performed by low‐energy collision‐induced dissociation tandem mass spectrometry. As a result of these experiments, the sequences of various tryptic peptides have been elucidated. The database search has shown that Atlantic cod vitellogenin shares a series of common peptides with the two different known vitellogenin sequences of haddock, a closely related species. These findings allow us to propose that Atlantic cod might also co‐express at least two distinct forms of vitellogenin. Copyright © 2005 John Wiley & Sons, Ltd.
Total synthesis of ciguatoxin CTX3C: a venture into the problems of ciguatera seafood poisoning
Authors: Hirama Masahiro 
Published: July 2005

AbstractAfter a twelve‐year struggle, the total synthesis of ciguatoxin CTX3C has been achieved. Annually, more than 20,000 people worldwide suffer from ciguatera seafood poisoning. The extremely small amounts of the causative neurotoxin, ciguatoxin, in fish hampered the isolation, structural elucidation, detailed biological study, and preparation of anti‐ciguatoxin antibodies for detecting these toxins. The large (3 nanometers long) and complicated molecular structure of ciguatoxins hindered chemists from completing a total synthesis. The chemical synthesis of CTX3C, determination of the absolute configuration, and synthesis‐based preparation of the monoclonal antibodies as well as the effect of synthetic CTX3C on voltage‐sensitive sodium channels are outlined. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 240–250; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20049
Characterization of surface carbon films on weathered Japanese roof tiles by soft x‐ray spectroscopy
Authors: Muramatsu Yasuji , Yamashita Michiru , Motoyama Muneyuki , Hirose Mika , Denlinger Jonathan D. , Gullikson Eric M. , Perera Rupert C. C. 
Published: July 2005

AbstractThe effects of weathering on carbon films deposited on Japanese smoked roof tiles were investigated by soft x‐ray absorption and emission spectroscopy using synchrotron radiation. X‐ray absorption measurements revealed that weathering oxidizes the carbon films and that partial carboxy chemical bonding occurs. Incident angle‐dependent x‐ray absorption spectra in the C K region confirmed that the degree of the orientation at the surface of the oxidized carbon films decreases with weathering. However, the take‐off angle‐dependent C K x‐ray emission spectra showed that the orientation of the layered carbon structure is maintained in the bulk portion when weathered. Therefore, it is confirmed that oxidation proceeds from the surface of the carbon films. Weathering degrades and oxidizes the surface carbon films, which causes the metallic silver color to change to darker gray. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of Intraperitoneal Application of an Endotoxin Inhibitor on Survival Time in a Laparoscopic Model of Peritonitis in Rats
Authors: Kuhn Roger , Schubert Daniel , Tautenhahn Joerg , Nestler Gerd , Schulz Hans‐Ulrich , Bartelmann Maike , Lippert Hans , Pross Matthias 
Published: August 2005

AbstractGram‐negative sepsis due to fecal peritonitis is a hazardous disease with a high percentage having a lethal course. The inflammatory effects are induced by endotoxin release. We performed this study to evaluate the potential of direct intraperitoneal application of an endotoxin inhibitor in a laparoscopic peritonitis model in rats. The human feces specimen was prepared, and a standard fecal specimen (0.5 ml/kg b.w.) was applied via minilaparotomy. The rats were randomized to two studies. First, rats were randomized to three groups to define the survival time: (1) rats without further manipulation; (2) rats with laparoscopic lavage using NaCl; (3) rats with laparoscopic lavage using endotoxin inhibitor. Second, rats underwent the same procedure used in the first part of the study and an additional group with only NaCl lavage without peritonitis was randomized. To evaluate the immunologic or biochemical effects, animals were killed at a standard time of 20 hours until the postmortem examination was established. Interleukins 6 and 10 (IL‐6, IL‐10), malondialdehyde, and protein carbonyl group levels in plasma and particularly in peritoneal fluid were assayed. The first part of the experiment showed significantly increased survival after endotoxin inhibitor lavage. In the second part, administration of endotoxin inhibitor intraperitoneally caused a significant reduction of IL‐6 in the peritoneal fluid, in contrast to that in the other groups. Laparoscopic application of endotoxin inhibitor intraperitoneally thus produced a beneficial effect on survival and reduction of IL‐6 in peritoneal fluid. Hence, it is possible to influence the inflammation cascade by causing intraperitoneal endotoxin inhibition.