bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyelectrolyte Membranes Based on Sulfonated Syndiotactic Polystyrene in Its Clathrate Form
Authors: Borriello A. , Lavorgna M. , Malagnino N. , Mensitieri G. , Napoletano T. , Nicolais L. 
Published: November 2004

AbstractRecently, more and more attention has been focused on new techniques for energy production also in view of environmental problems. A noticeable device is small fuel cell that converts chemical energy into electric energy by electrochemical reaction of hydrogen with oxygen, and exhibits a high‐energy efficiency. Conventional small fuel cells have been classified into phosphoric acid‐type fuel cells, molten carbonate‐type fuel cells, solid oxide‐type fuel cells, solid polymer type fuel cells, etc., according to the type of electrolyte used. The target of this work is the development of a new process to build up polyelectrolyte membranes, for polymer type fuel cell (PEM), by sulfonating syndiotactic polystyrene in its clathrate form. The polyelectrolyte membranes of this paper are inexpensive and exhibit good long‐term stability and ion exchange capability.
On the Physical Parameters and Relaxation Processes in Nematic Azobenzene Polymers for Optical Nanowriting
Authors: Andreozzi Laura , Faetti Massimo , Galli Giancarlo , Giordano Marco , Palazzuoli Diego 
Published: November 2004

AbstractThe possibility of achieving devices for rewritable optical storage is provided by liquid‐crystalline polymers with azobenzene side groups, because they undergo photochemically induced trans‐cis reversible isomerization. In this work we overview our investigations into a nematic azobenzene‐polymethacrylate (PMA4) as a suitable material for optical nanowriting. Relaxation processes over different time‐length scales are discussed with particular reference to understanding the interplay between homogeneity at the molecular level, bit stability and working temperature range.
Physical and Chemical Characterization of Cellulose Based Textiles Modified by Periodate Oxidation
Authors: Princi Elisabetta , Vicini Silvia , Pedemonte Enrico , Proietti Noemi , Capitani Donatella , Segre Anna Laura , D'Orazio Loredana , Gentile Gennaro , Polcaro Carmen , Martuscelli Ezio 
Published: November 2004

AbstractConversion of dihydroxyl groups to dialdehyde by periodate oxidation is a useful method widely used in derivatization of cellulose to activate the polymer to further reactions as grafting polymerization. To investigate the cellulose behavior at different level of oxidation and to better understand the influence of the crystallinity on the effects induced by oxidative reactions on different cellulose materials, linen and cotton textiles have been oxidized with periodate solutions in different conditions. Oxidized cellulose samples have been characterized by several techniques: solid‐state 13C NMR, Wide Angle X‐Ray diffraction, and SEM. Moreover the mechanical properties of the untreated and oxidized yarns have been evaluated by means of tensile tests, the oxidation degree has been measured by means of the hydroxylamine hydrochloride method.
Reactive Polymeric Dyes as Textile Auxiliaries
Authors: Altomare Angelina , Ciardelli Francesco , Solaro Roberto 
Published: November 2004

AbstractCommercial and synthetic azobenzene derivatives were used for the synthesis of hydrophilic polymeric dyes. Two strategies based respectively on the polymerization of dye methacrylic derivatives with different monomers and on the functionalization of reactive polymers were investigated. Polymers containing rather small amounts of the selected dyes were generally obtained, very likely because of the electron withdrawing effect of azo chromophores. Almost quantitative conversions were recorded in the reaction of commercial dyes with maleic anhydride/methyl vinyl ether alternating copolymers. Some of the prepared polymeric dyes were preliminarily tested as textile finishing agents.
Multi‐Layer Pipes for Hydrocarbons Conveyance
Authors: Bulleri Barbara , Genoni Massimo , Gallone Giuseppe , Marchetti Augusto 
Published: November 2004

AbstractThe replacement of metals with plastics in piping systems is a well established practice in a vast range of public and industrial applications. However, difficulties still exist, mainly related to the limited chemical resistance of the polymers commonly used in pipe manufacturing to some conveyed fluids. This prevents using plastic pipes in important applications such as the transport of liquid hydrocarbons, particularly in oil fields. The use of chemically resistant polymers, such as fluorinated polyolefins, is precluded by high cost and poor mechanical properties. Co‐extrusion of multi‐layer pipes carrying an internal chemically resistant liner can be a viable alternative capable to extend the use of plastic pipes to refining and chemical industries. An experimental PE/PA multi‐layer pipe has been developed whose resistance to diffusion and mechanical properties have been tested. Tests in real oil fields confirm the good performance of the new pipes.
Single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization of vinyl chloride catalyzed by thiourea dioxide/octyl viologen in water/tetrahydrofuran at 25 °C
Authors: Percec Virgil , Popov Anatoliy V. , Ramirez‐Castillo Ernesto 
Published: November 2004

AbstractThe single‐electron‐transfer/degenerative‐chain‐transfer mediated living radical polymerization (SET–DTLRP) of vinyl chloride (VC) in H2O/tetrahydrofuran at 25 °C catalyzed by thiourea dioxide [(NH2)2CSO2] is reported. This polymerization occurs only in the presence of a basic sodium bicarbonate (NaHCO3) buffer and the electron‐transfer cocatalyst octyl viologen. The resulting poly(vinyl chloride) (PVC) has a number‐average molecular weight of 1500–7000 and a weight‐average molecular weight/number‐average molecular weight ratio of 1.5. This PVC does not contain detectable amounts of structural defects and has both active chloroiodomethyl and inactive chloromethyl chain ends. Because of possible side reactions caused by the primary sulfoxylate anion (SO), the catalytic activity of (NH2)2CSO2 in the SET–DTLRP of VC is lower than that of the single‐electron‐transfer agent sodium dithionite. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 287–295, 2005
Apparent upfreezing of stones in late‐Pleistocene coversand, Bełchatów vicinity, Central Poland
Authors: Gozdzik Jan S. , French Hugh M. 
Published: November 2004

AbstractStones lie within a well‐sorted coversand in central Poland. They are thought to have migrated to their present positions by upfreezing that occurred as permafrost aggraded beneath an accumulating dune‐sand surface. Some of the stones have risen as much as 1 m into the coversand. ‘Chimney‐like’ sedimentary structures are thought to indicate the path of upward migration. The dynamics of upfreezing in non‐frost susceptible sediment are difficult to understand without recourse to site‐specific factors. Copyright © 2004 John Wiley & Sons, Ltd.
Randomized, Double‐Blind, Placebo‐Controlled, Dose‐Escalating Study of Aerosolized Interferon Gamma‐1b in Patients With Mild to Moderate Cystic Fibrosis Lung Disease
Authors: Moss Richard B. , Mayer‐Hamblett Nicole , Wagener Jeffrey , Daines Cori , Hale Kathryn , Ahrens Richard , Gibson Ronald L. , Anderson Paula , Retsch‐Bogart George , Nasr Samya Z. , Noth Imre , Waltz David , Zeitlin Pamela , Ramsey Bonnie , Starko Karen 
Published: November 2004

AbstractInterferon gamma‐1b (IFN‐γ1b) is a pleiotropic cytokine with immunomodulatory activities that could decrease bacterial burden, inflammation, and obstruction in patients with CF. Patients with CF (≥12 years old, FEV1 ≥40% predicted) were randomly assigned to sequential dose cohorts inhaling 500 μg IFN‐γ1b, 1,000 μg IFN‐γ1b, or placebo by Respirgard II® nebulizer thrice weekly for 12 weeks. Sputum bacterial density and spirometry were measured. Safety, antibiotic use, hospitalization, and sputum neutrophils, elastase, DNA, IL‐8, and myeloperoxidase were also evaluated. Sixty‐six patients (mean age, 24 years, with mean baseline FEV1 of 74 ± 20 (SD) percent predicted) were studied. One patient had bronchospasm after the first dose of IFN‐γ1b; the overall withdrawal rate was 15% (5 in the placebo group, 2 in the 500‐μg IFN‐γ1b group, and 3 in the 1,000 μg IFN‐γ1b group). The 500‐μg IFN‐γ1b dose was well‐tolerated, but the 1,000‐μg dose cohort, who had a higher baseline bacterial density than placebo patients (mean difference, 1.2 log10 CFU/g sputum, 95% confidence interval (CI), 0.1,2.8, P = 0.04), had 24% more hospitalizations for exacerbation than placebo patients (95% CI, 2,45%, P = 0.05). There was a 0.12‐l difference between the 500‐μg IFN‐γ1b and placebo groups with respect to the 12‐week change in FEV1 (active group minus placebo group, 95% CI, −0.03,0.26, P = 0.11), as compared to a 0.01‐l difference between the 1,000‐μg IFN‐γ1b and placebo groups (95% CI, −0.16,0.17, P = 0.96). No effects of IFN‐γ1b were seen in sputum bacterial density or inflammatory biomarkers at 12 weeks. Aerosolized IFN‐γ1b did not improve pulmonary function, reduce sputum bacterial density, or affect inflammatory sputum markers in patients with mild‐moderate lung disease. Pediatr Pulmonol. 2005; 39:209–218. © 2004 Wiley‐Liss, Inc.
Effect of T‐R conformational change on sickle‐cell hemoglobin interactions and aggregation
Authors: Vaiana S. M. , Rotter M. A. , Emanuele A. , Ferrone F. A. , Palma‐Vittorelli M. B. 
Published: November 2004

AbstractWe compare the role of a conformational switch and that of a point mutation in the thermodynamic stability of a protein solution and in the consequent propensity toward aggregation. We study sickle‐cell hemoglobin (HbS), the β6 Glu‐Val point mutant of adult human hemoglobin (HbA), in its R (CO‐liganded) conformation, and compare its aggregation properties to those of both HbS and HbA in their T (unliganded) conformation. Static and dynamic light scattering measurements performed for various hemoglobin concentrations showed critical divergences with mean field exponents as temperature was increased. This allowed determining spinodal data points TS(c) by extrapolation. These points were fitted to theoretical expressions of the TS(c) spinodal line, which delimits the region where the homogeneous solution becomes thermodynamically unstable against demixing in two sets of denser and dilute mesoscopic domains, while remaining still liquid. Fitting provided model‐free numerical values of enthalpy and entropy parameters measuring the stability of solutions against demixing, namely, 93.2 kJ/mol and 314 J/°K‐mol, respectively. Aggregation was observed also for R‐HbS, but in amorphous form and above physiological temperatures close to the spinodal, consistent with the role played in nucleation by anomalous fluctuations governed by the parameter ϵ = (T − TS)/TS. Fourier transform infrared (FTIR) and optical spectroscopy showed that aggregation is neither preceded nor followed by denaturation. Transient multiple interprotein contacts occur in the denser liquid domains for R‐HbS, T‐HbS, and T‐HbA. The distinct effects of their specific nature and configurations, and those of desolvation on the demixing and aggregation thermodynamics, and on the aggregate structure are highlighted. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Average peptide score: a useful parameter for identification of proteins derived from database searches of liquid chromatography/tandem mass spectrometry data
Authors: Chepanoske Cindy Lou , Richardson Bonnie E. , von Rechenberg Moritz , Peltier John M. 
Published: November 2004

AbstractThe quantity and variable quality of data that can be generated from liquid chromatography (LC)/mass spectrometry (MS)‐based proteomics analyses creates many challenges in interpreting the spectra in terms of the actual proteins in a complex sample. In spite of improvements in algorithms that match putative peptide sequences to MS/MS spectra, the assembly of these lists of possible or probable peptides into a ‘correct’ set of proteins is still problematic. We have observed a trend in a simple relationship, derived from standard database search outputs, which can be useful in assessing the quality of a MS/MS‐based protein identification. Specifically, the ratio of the protein score and number of non‐redundant peptides, or average peptide score (APS), can facilitate initial filtering of database search results in addition to providing a useful measure of confidence for the proteins identified. This parameter has been applied to results from the analysis of multi‐protein complexes derived from pull‐down experiments analyzed using a two‐dimensional LC/MS/MS workflow. In particular, the complex list of protein identifications derived from a drug affinity pull‐down with immobilized ampicillin and an E. coli lysate was greatly simplified by applying the APS as a filter, allowing for facile identification of the penicillin‐binding proteins known to interact with ampicillin. Furthermore, an APS threshold can be used for any data sets derived from electrospray ionization (ESI)‐ or matrix‐assisted laser desorption/ionization (MALDI)‐MS/MS experiments and is also not specific to any database search program. Copyright © 2004 John Wiley & Sons, Ltd.
Automated immobilized metal affinity chromatography/nano‐liquid chromatography/electrospray ionization mass spectrometry platform for profiling protein phosphorylation sites
Authors: Ficarro Scott B. , Salomon Arthur R. , Brill Laurence M. , Mason Daniel E. , Stettler‐Gill Michelle , Brock Ansgar , Peters Eric C. 
Published: November 2004

AbstractA versatile integrated system has been developed for the automated enrichment and analysis of phosphopeptides by immobilized metal affinity chromatography/nano‐liquid chromatography/electrospray ionization mass spectrometry (IMAC/nano‐LC/ESI‐MS). This system utilizes two independently controlled high‐performance liquid chromatography (HPLC) pumps, an autosampler and microvalves to prepare and elute samples into an ion trap mass spectrometer. The use of robust reversed‐phase HPLC columns with integrated ESI emitter tips enables the reproducible detection and identification of low‐femtomole quantities of phosphopeptides. The entire system is coordinated through a simple user interface by customized software. The ruggedness of the system is demonstrated by highly reproducible analyses of single and multi‐protein digests, while its utility is demonstrated by the thorough evaluation of the relative immunoprecipitation efficiencies of several commercially available anti‐phosphotyrosine antibodies. Copyright © 2004 John Wiley & Sons, Ltd.
Validating regulatory‐compliant wide dynamic range bioanalytical assays using chip‐based nanoelectrospray tandem mass spectrometry
Authors: Wickremsinhe Enaksha R. , Ackermann Bradley L. , Chaudhary Ajai K. 
Published: November 2004

AbstractAutomated chip‐based infusion nanoelectrospray ionization coupled to tandem mass spectrometry (nanoESI‐MS/MS) was used to validate a bioanalytical assay conforming to United States Food and Drug Administration (FDA) regulatory guidelines and Good Laboratory Practices (GLP). Reboxetine was used as the analyte fortified in dog plasma along with an analog internal standard (IS). The best nanoESI response for reboxetine was observed with 90% acetonitrile (ACN)/water without any mobile phase modifiers. The analyte and IS were extracted from dog plasma samples by liquid‐liquid extraction (LLE). The supernatant was concentrated to dryness and redissolved in 90% ACN/water for nanoESI. Selected reaction monitoring (SRM) data were collected for all samples to generate ion current profiles with a base width of approximately 20 s. Selectivity experiments showed no interferences in blank plasma samples. Interferences as a result of in‐source collision‐induced dissociation of metabolites were not an issue due to the previously documented metabolism of reboxetine. Matrix suppression was evaluated across multiple lots of dog plasma as well as over different animal species (rabbit, rat, mouse) and different anticoagulants (heparin, EDTA). Matrix suppression ranged from approximately 30–60% across the different lots, species etc.; however, in all instances, the analyte and the IS were suppressed by similar amounts, suggesting the similarity in ionization properties between the two. A three‐batch validation was performed (each batch consisting of four different concentrations, six replicates of each concentration) and demonstrated inter‐assay accuracy (% relative error; RE) of less than ±8% and an inter‐assay precision (% relative standard deviation; RSD) of less than 7%, thus meeting regulatory guidelines. A comparison of analyses by nanoESI‐MS/MS and liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) showed that nanoESI‐MS/MS had a greater slope for the calibration standard curve compared to LC/MS/MS, indicating greater sensitivity for the former technique. It is also noteworthy that the amount of sample infused during nanoESI‐MS/MS was approximately 80‐fold less compared to the amount of sample injected during LC/MS/MS. The absence of carryover (attributed to the lack of a common fluid path) in the nanoESI technique enabled the extension of the assay linear dynamic range to 500 000‐fold, and the possibility of analyzing samples in a single batch without the need for re‐analysis of samples with high concentrations. This technology offers the possibility for increased throughput for studies supporting drug development by providing fast data turnaround for assays conforming to regulatory guidelines and GLPs. Copyright © 2004 John Wiley & Sons, Ltd.
Further studies on the fragmentation of protonated ions of peptides containing aspartic acid, glutamic acid, cysteine sulfinic acid, and cysteine sulfonic acid
Authors: Men Lijie , Wang Yinsheng 
Published: November 2004

AbstractHere we examined the fragmentation, on a quadrupole ion‐trap mass spectrometer, of the protonated ions of a group of peptides containing one arginine and two different acidic amino acids, one being aspartic acid (Asp) or glutamic acid (Glu) and the other being cysteine sulfinic acid [C(SO2H)] or cysteine sulfonic acid [C(SO3H)]. Our results showed that, upon collisional activation, the cleavage of the peptide bond C‐terminal to C(SO2H) is much more facile than that of the peptide bond C‐terminal to Asp, Glu, or C(SO3H). There is no significant difference, however, in susceptibility to cleavage of peptide bonds that are C‐terminal to Asp, Glu, and C(SO3H). To understand these experimental observations, we carried out B3LYP/6‐31G* density functional theory calculations for a model cleavage reaction of GXG → b2 + Gly, in which X is Asp, Glu, C(SO2H), or C(SO3H). Our calculation results showed that the cleavage reaction is thermodynamically more favorable when X = C(SO2H) than when X = Asp or C(SO3H). We attributed the less facile cleavage of the amide bond after Glu to that the formation of a six‐membered ring b ion for Glu‐bearing peptides is kinetically not as favorable as the formation of a five‐membered ring b ion for peptides containing the other three acidic amino acids. The results from this study may provide useful tools for peptide sequencing. Copyright © 2004 John Wiley & Sons, Ltd.
An age‐adjusted bootstrap‐based Poly‐k test
Authors: Moon Hojin , Ahn Hongshik , Kodell Ralph L. 
Published: November 2004

AbstractThe assumption of an asymptotic normal distribution of some test statistics may be invalid in certain dose–response trend tests. For instance, the survival‐adjusted Cochran–Armitage test, known as the Poly‐k test, is asymptotically standard normal under the null hypothesis. However, the asymptotic normality is not valid if there is a deviation from the tumour onset distribution that is assumed in this test or if the competing risks survival rates differ across groups. We develop an age‐adjusted bootstrap‐based method to assess the significance of assumed asymptotic normal tests for animal carcinogenicity data. The proposed method differs from conventional bootstrap methods in the aspect of preserving the mortality rate in each dose group under the null hypothesis of equal tumour incidence rates among the groups. We investigate an empirical distribution of the Poly‐3 (P3) trend test statistic using the proposed age‐adjusted bootstrap‐based method and compare it with the P3 test statistic referenced to the assumed standard normal distribution. A simulation study is conducted to evaluate the robustness of these tests to various Weibull‐family tumour onset distributions. The proposed method is applied to National Toxicology Program data sets to evaluate a dose‐related trend of a test substance on the incidence of neoplasms. Published in 2004 by John Wiley & Sons, Ltd.
The future for treatment by bone marrow transplantation for adrenoleukodystrophy, metachromatic leukodystrophy, globoid cell leukodystrophy and Hurler syndrome
Authors: Krivit W. , Lockman L. A. , Watkins P. A. , Hirsch J. , Shapiro E. G. 
Published: November 2004

SummaryWithin the past decade, bone marrow transplantation has been applied to over 200 patients worldwide with the intention of treating storage diseases. Bone marrow transplantation has provided a method for treatment of adrenoleukodystrophy, metachromatic leukodystrophy, globoid cell leukodystrophy and Hurler syndrome. After engraftment, significant improvement in the clinical course of each of these diseases occurs. Survival data of engrafted patients are superior to those of non‐transplanted. Engraftment and the resulting enzymatic reconstitution are concordant. Outcomes based on neuropsychological tests indicate continued maintenance and in some cases increase in cognitive function. Magnetic resonance imaging as well as spectroscopic examinations of the brain provide further evidence that positive changes occur in the central nervous system following long‐term engraftment. A better quality of life follows engraftment. Greater gains from use of bone marrow transplantation for these particular storage diseases will occur in the future. Earlier diagnosis will allow bone marrow transplantation in the presymptomatic stage at a younger age, providing an enhancement of positive effects noted from such treatment. At the same time, advances in bone marrow technology will serve to reduce the risk factors involved with the bone marrow transplantation process itself. These two factors taken together will be more than additive in providing benefits from use of bone marrow transplantation.
Neuropsychological outcomes of several storage diseases with and without bone marrow transplantation
Authors: Shapiro E. G. , Lockman L. A. , Balthazor M. , Krivit W. 
Published: November 2004

SummaryNeuropsychological assessment is essential in providing documentation of the untreated natural history of storage diseases associated with dementia and quantifying the effectiveness of treatment on central nervous system function. Baseline characterization and outcome of bone marrow transplantation (BMT) for three leukodystrophies and three mucopolysaccharidoses are presented. Results suggests that BMT for Hurler syndrome, adrenoleukodystrophy, and globoid cell leukodystrophy can be effective in preventing dementia if done early enough in the disease. Sanfilippo and Hunter syndromes do not benefit and BMT is not recommended. For metachromatic leukodystrophy, BMT is not recommended for symptomatic early‐onset forms of the disease. Further longitudinal follow‐up is needed to determine whether the benefits outweigh the risks of BMT for late‐onset and preclinical metachromatic leukodystrophy.