bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacovigilance of over‐the‐counter products based in community pharmacy: methodological issues from pilot work conducted in Hampshire and Grampian, UK
Authors: Layton D. , Sinclair H. K. , Bond C. M. , Hannaford P. C. , Shakir S. A. W. 
Published: October 2002

AbstractPurposeThe incidence of serious adverse events from non‐prescription medicines remains to be established. The aim of this initial pilot work, using an observational cohort design, was to determine the feasibility of conducting a pharmacovigilance study of a non‐prescription medicine, based in community pharmacies.MethodCommunity pharmacists from Grampian, Scotland, and Hampshire, England, recruited user‐purchasers of ibuprofen. Exposure data were collected from a series of self‐completed questionnaires. Outcome data were any new symptoms, use of concomitant medication and subsequent health‐care utilization.ResultsA total of 1021 eligible customers were recruited, 6.4% (466/7320) and 48.2% (555/1152) by the Hampshire and Grampian networks respectively. The cohorts differed with regard to age, smoking and socio‐economic status, reason for purchase and recommendation, and duration of use. The two cohorts reported different use of concomitant medication (46.0 and 65.5%), asthma (7.2 and 10.5%), stomach/peptic ulcer (3.5 and 2.1%), a higher prevalence of gastrointestinal symptoms post‐compared to pre‐purchase (12.9 vs. 7.2%, p=0.0006 and 8.8 vs. 5.8%, p=0.034), ingestion of doses in excess of the licensed non‐prescription dose by 5.1 and 3.9%, and discontinuation of treatment because the medicine upset them by 4.5 and 3.1%, respectively. Most participants did not seek medical advice for their symptoms.ConclusionGreater vigilance is required for adverse events that may be attributable to non‐prescription product use. Development of pharmacovigilance models using community pharmacies is one means of systematically collecting information regarding drug safety. Further work is needed to identify a method which maximizes patient recruitment whilst maintaining acceptable follow‐up rates. Copyright © 2002 John Wiley & Sons, Ltd.
Substituent effects in reductions of heteroaromatic cations
Authors: Heyes David , Menon Ramesh S. , Watt C. Ian. F. , Wiseman Jake , Kubinski Przemyslaw 
Published: October 2002

AbstractA set of 11 each of 2,4,6‐triphenylpyrylium, ‐thiopyrylium and ‐N‐methylpyridinium tetrafluoroborates carrying a range of substituents in the phenyl rings were prepared. First and second wave reduction potentials were determined. For the thiopyrylium series there are linear correlations between scaled potentials (E°/0.05915) and summed Hammett constants for substituents in the pendant phenyl groups (σ = 2.29 and 3.38 for first and second waves respectively). For the pyrylium series, a good linear relationship (σ = 2.79) is obtained for all substituent patterns for the first wave reduction potentials, but for the second wave there are separate correlations for salts carrying substituents in the 4‐phenyl and for those carrying substituents in 2‐ and 6‐phenyls. For the pyridinium series, the first wave potentials show separate correlations for salts carrying substituents in the 4‐phenyl and for those carrying substituents in 2‐and 6‐phenyls, but a single linear relationship for the second wave potentials. These are related to particular structural features in the cations, radicals and anions in each series. Rates and products were determined for reductions of the pyrylium and thiopyrylium cations by sodium cyanoborohydride and of all cations by sodium borohydride in acetonitrile solution. Reactions are first order in reducing agent and cation. Primary kinetic isotope effects were determined for borohydride reduction of the least reactive of each of the series of cations. Plots of logarithms of second‐order rate constants against summed Hammett constants for substituents in the pendant phenyl groups are linear for all combinations of reagent and cation with 0.91 < σ < 1.50 across all substituent patterns. For parent pyrylium and thiopyryliums, kBH4/kCNBH3 = 8.4 × 104 and 1.5 × 104, respectively, and for reductions by borohydride the reactivities of the pyrylium, thiopyrylium and pyridinium, series decrease in the order 1.4 × 105:8.8 × 103:1. Constant selectivities are not observed. Comparison of the correlations for electrochemical reduction and for hydride addition leads to the conclusion that charge neutralization in the hydride addition transition states runs ahead of bonding changes at the originating B—H bond. Copyright © 2002 John Wiley & Sons, Ltd.
Classifications of families of homologous organic compounds based on energy by means of ab initio ­HF, MP2 and DFT optimizations
Authors: Neugebauer Alexander , Häfelinger Günter 
Published: October 2002

AbstractA method is suggested for combining the quantum chemical principle of isolated molecules and the systematics of homologous families for different functional groups in traditional organic chemistry. The classification of organic compounds is performed by statistical treatments of fundamental quantum mechanical quantities such as total and partial energies. We used the total energies (computed by DFT BLYP and B3LYP, HF and MP2 methods, which are size‐extensive, applying the 6–31 G** and some other basis sets) of isolated molecules obtained by gradient optimizations to classify homologous series of organic compounds by linear least‐squares regressions versus the total number of electrons. Two numerical parameters, slope (h) and intercept (s), are obtained characterizing each family of homologous compounds. Families of for example 17 different functional groups of the same CH2‐homologous unit are grouped on parallel lines with the same slope h, differing only in their s parameters. Isomeric compounds differ in their s values if they belong to the same homologous unit. Compounds of other homologous units (conjugated alkenes, cumulenes and benzenoides) are found with different slopes h on regression lines. Energy partitioning leads also to linear regressions of different statistical accuracy for the components which add fully to the observed h and s parameters. The h and s parameters allow the prediction of unknown total energies of homologous compounds from total energies of a subset of smaller compounds which belong to the same homologous family. Likewise, atomization energies can be predicted using the derived h and s parameters. Copyright © 2002 John Wiley & Sons, Ltd.
Proton affinities of N—O anions and their protonated forms
Authors: Kazazić Saša , Kazazić Snježana P. , Klasinc Leo , McGlynn Sean P. , Pryor William A. 
Published: October 2002

AbstractThe proton affinities (PA) of several N—O anions, namely the singly charged anions nitrite, peroxynitrite, nitrate and peroxynitrate and the doubly charged anions cis‐ and trans‐hyponitrite and oxyhyponitrite, were calculated to be 1413.8, 1440.5, 1348.5, 1414.7, 2065.2, 1987.4 and 1977.9 kJ mol−1, respectively. The PA of the corresponding conjugate acids were 780.3, 749.8, 746.0, 724.7, 1394.9, 1448.9 and 1340.7 kJ mol−1, respectively. The PA of cis‐ and trans‐hyponitric and oxyhyponitric acid were 906.7, 723.8 and 728.2 kJ mol−1, respectively. Comparison with the available experimental values for the acids indicates that the calculated values are good estimates of these important quantities. Copyright © 2002 John Wiley & Sons, Ltd.
Synthesis and characterization of aromatic polyamides containing alkylphthalimido pendent groups
Authors: Ferrero E. , Espeso J. F. , de la Campa J. G. , de Abajo J. , Lozano A. E. 
Published: October 2002

AbstractA series of polyisophthalamides containing pendent phthalimido groups and flexible side spacers were prepared from four novel diacids and three commercial aromatic diamines. These polyamides were prepared in high yields and with high molecular weights by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 70,000–137,000 and 47,000–86,000 g/mol, respectively. The novel polyamides were amorphous and readily soluble and showed glass‐transition temperatures of 150–240 °C, as measured by differential scanning calorimetry. Thermogravimetric analysis showed that the 10% weight‐loss temperatures in nitrogen were 355–430 °C, a significant improvement in thermal stability having been observed with the increase in the side‐chain length. A theoretical quantum mechanical study was successfully carried out to explain these results. Flexible and tough films, cast from polymer solutions, showed tensile strengths of 50–125 MPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3711–3724, 2002
Effects of the structure and morphology of zinc glutarate on the fixation of carbon dioxide into polymer
Authors: Meng Y. Z. , Du L. C. , Tiong S. C. , Zhu Q. , Hay Allan S. 
Published: October 2002

AbstractZinc glutarates were synthesized from zinc oxides with varying purities via different stirring routes. The particle size and structure of these zinc glutarates were determined by wide‐angle X‐ray diffraction, transmission electron microscopy, and the laser particle size analyzer technique. The results demonstrated that the crystallinity and crystalline perfectness of zinc glutarate are the crucial factors that affect the catalytic activity for the copolymerization of carbon dioxide (CO2) and propylene oxide (PO). Additionally, the catalyst with a small particle size dramatically increased the yield of the copolymerization between CO2 and PO. High‐molecular‐weight and regular molecular structure poly(propylene carbonate)s (PPC)s were obtained from CO2 and PO with the synthesized zinc glutarates. Very high catalytic activity of 160.4 g polymer/g catalyst was afforded. The NMR technique revealed that the PPC copolymer exhibits an exact alternating copolymer structure. The relationships between the crystallinity and the particle size of catalyst with the catalytic activity are correlated and discussed. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3579–3591, 2002
Dimethyldioxirane as a new and effective oxidation agent for the epoxidation of α,ω‐di(isobutenyl)polyisobutylene: A convenient synthesis of α,ω‐di(2‐methyl‐3‐hydroxypropyl)‐polyisobutylene
Authors: Kéki Sándor , Nagy Miklós , Deák György , Lévai Albert , Zsuga Miklós 
Published: October 2002

AbstractThe synthesis and characterization of α,ω‐di(2‐methyl‐2,3‐epoxypropyl)polyisobutylene are reported. The epoxidation of α,ω‐di(isobutenyl)polyisobutylene was achieved at room temperature with dimethyldioxirane, which proved to be a very effective reagent for epoxidation without the formation of byproducts. A very good agreement was found for the conversion determined by 1H NMR and matrix‐assisted laser desorption/ionization mass spectrometry (MALDI HMS). The epoxy end groups were converted quantitatively into aldehyde termini with zinc bromide as a catalyst. The aldehyde groups were then reduced with LiAlH4 into primary hydroxyl functions to obtain α,ω‐di(2‐methyl‐3‐hydroxylpropyl)polyisobutylene with high efficiency. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3974–3986, 2002
Novel block ionomers II. Synthesis and characterization of polyisobutylene‐based block cationomers
Authors: Fang Zheng , Kennedy Joseph P. 
Published: October 2002

AbstractVarious novel block cationomers consisting of polyisobutylene (PIB) and poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) segments were synthesized and characterized. The specific targets were various molecular weight diblocks (PIB‐b‐PDMAEMA+) and triblocks (PDMAEMA+‐b‐PIB‐b‐PDMAEMA+), with the PIB blocks in the DPn = 50–200 range (number‐average molecular weight = 3,000–9000 g/mol) connected to blocks of PDMAEMA+ cations in the DPn = 5–20 range (where DP is the number‐average degree of polymerization). The overall synthetic strategy for the preparation of these block cationomers had four steps: (1) synthesis by living cationic polymerization of mono‐ and diallyltelechelic polyisobutylenes, (2) end‐group transformation to obtain PIBs fitted with termini capable of mediating the atom transfer radical polymerization (ATRP) of DMAEMA, (3) ATRP of DMAEMA, and (4) quaternization of PDMAEMA to PDMAEMA +I− by CH3I. Scheme 1 shows the microarchitecture and outlines the synthesis route. Kinetic and model experiments provided guidance for developing convenient synthesis methods. The microarchitecture of PIB–PDMAEMA di‐ and triblocks and the corresponding block cationomers were confirmed by 1H NMR and FTIR spectroscopy and solubility studies. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3679–3691, 2002
Synthesis of novel ladder polymers of poly(3,4‐dihydro‐2H‐pyran‐2‐methanol)
Authors: Abdelaal Magdy Youssef 
Published: October 2002

AbstractPolydi(3,4‐dihydro‐2H‐pyran‐2‐methyl) esters of oxalic, adipic, and phthalic acids were prepared at different temperatures in the presence of different cationic initiators, namely, the boron trifluoride/diethyl ether complex system, anhydrous ferric chloride, and p‐toluene sulfonic acid. The obtained polymers were hydrolyzed under basic conditions, and the polydispersity indices of these polymers were determined before and after hydrolysis. The results are discussed to shed some light on the ability to use this analysis to investigate the precise structure of the obtained polymers and to predict the ability of these polymers to form ladder or semiladder polymers. Characteristics of such polymers were dependent, to some extent, on the type of crosslinks and the cationic initiators used for polymerization as well as the reaction temperature. It seems possible to optimize the conditions leading to formation of ladder or semiladder polydi(3,4‐dihydro‐2H‐pyran‐2‐methyl) esters of oxalic acid and adipic acid, respectively. The ladder structure was confirmed through determination of the polydispersity index before and after hydrolysis of the polymer formed at different temperatures and through computer‐aided molecular modeling. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3909–3915, 2002
Modified cubic spherosilicates as macroinitiators for the synthesis of inorganic–organic starlike polymers
Authors: Holzinger Dieter , Kickelbick Guido 
Published: October 2002

AbstractModified cubic spherosilicate cages of the type [Si8O20]8− were used as rigid, inorganic cores for the synthesis of macroinitiators for thermal and photoinduced free radical and controlled radical polymerizations. Two different routes to these macroinitiators were investigated: the direct modification of the octaanion with chlorosilane‐functionalized initiators and the hydrosilation of SiH‐substituted cages. The latter synthesis of the macroinitiators resulted in more defined reaction products. With these compounds, the polymerizations of styrene and methyl methacrylate were carried out. The free radical polymerizations showed broad polydispersities based on coupling reactions, whereas the copper‐mediated atom transfer radical polymerizations (ATRP) revealed that good polymerization control could be achieved with the prepared initiators. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3858–3872, 2002
Synthesis of π‐conjugated oligomer that can form metallo polymers
Authors: El‐Ghayoury Abdelkrim , Schenning Albertus P. H. J. , Meijer E. W. 
Published: October 2002

AbstractAn oligo(p‐phenylene vinylene) that contains terpyridine ligands has been synthesized. Upon addition of metal ions, a π‐conjugated metallo polymer is formed in which the well‐defined character of oligomers and the material properties of polymers are combined. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4020–4023, 2002
Emulsion polymerization of divinyl monomers stabilized by sodium dodecyl sulfate and bis(2‐ethylhexyl)sulfosuccinate sodium salt
Authors: Gawdzik Barbara , Maciejewska Małgorzata 
Published: October 2002

AbstractThe emulsion polymerization of divinyl monomers is investigated. Emulsions were obtained in the presence of sodium dodecyl sulfate and bis(2‐ethylhexyl)sulfosuccinate sodium salt as surfactants. The influence of monomer type and kind of surfactant on the particle size distribution is studied. The porous structure of the broken emulsions is also determined. The results indicate that the diameter of nanospheres obtained from two divinyl monomers are significantly larger than those obtained from polystyrene. Aggregation of the particles and the pore‐forming diluent added to the emulsion are responsible for the existence of pores. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3967–3973, 2002
Effect of central spacer chain structure on cationic cyclopolymerization tendency of divinyl ethers
Authors: Hashimoto Tamotsu , Ohashi Minoru , Kodaira Toshiyuki 
Published: October 2002

AbstractTo clarify the effects of the central spacer chain structure of divinyl ethers on their cationic cyclopolymerization tendencies, 1,4‐bis[(2‐vinyloxy)ethoxy]benzene (1), 1,4‐bis[(2‐vinyloxy)ethoxy]butane (2), 1,6‐bis[(2‐vinyloxy)ethoxy]hexane (3), 1,8‐bis[(2‐vinyloxy)ethoxy]octane (4), and 1,4‐bis[(4‐vinyloxy)butoxy]butane (5) were polymerized with the hydrogen chloride/zinc chloride (HCl/ZnCl2) initiating system in methylene chloride (CH2Cl2) at 0 °C at low initial monomer concentration ([M]0 = 0.15 M). The polymerizations of divinyl ethers 2 and 3 gave soluble polymers quantitatively. In contrast, the polymerizations of divinyl ethers 1, 4, and 5 underwent gel formation at high monomer conversion. The content of the unreacted vinyl groups of the obtained soluble polymers was measured by 1H NMR spectroscopy. Judging from the relatively low vinyl contents of the polymers produced even in the early stage of the polymerization (monomer conversion < ∼20%), the cyclopolymerization occurred to some extent for 2, 3, and 4. On the contrary, the polymers produced from 1 and 5 exhibited the relatively high vinyl content, indicating that the cyclopolymerization tendencies of 1 and 5 were lower than those of 2, 3, and 4. These results are discussed in terms of the structural variety of the spacer chains: (1) the presence of benzene ring (1 vs 2), (2) their length (2 vs 3 and 4), and (3) the position of ether oxygen (4 vs 5). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4002–4012, 2002
Preparation and characterization of N‐methyl‐substituted polyurethane
Authors: Choi Hee‐Sung , Noh Si‐Tae 
Published: October 2002

AbstractWe prepared N‐methyl‐substituted polyurethanes with different substitution degrees from sodium hydride, methyl p‐toluene sulfonate, and polyether–polyurethane containing poly(oxytetramethylene) glycol, 4,4′‐diphenylmethane diisocyanate, and 1,4‐butanediol. The chemical structures were characterized with Fourier transform infrared and 1H NMR. To investigate the effects of the N‐substitution degree on the morphology, thermal stability, and mechanical properties, we used differential scanning calorimetry, thermogravimetric analysis, and a universal testing machine. As the substitution degree increased, the new free (1708 cm−1) and bonded (1650 cm−1) carbonyl peaks increased. There was no bonded carbonyl peak in fully substituted polyurethane because the urethane groups had no hydrogen. At a small substitution degree, we observed a slight increase in the glass‐transition temperature and decrease in the endotherms of soft‐segment and hard‐segment domains due to the decrease in the hard‐segment domain and the increase in the urethane groups in the soft‐segment domain. The hard‐segment domain decreased and then disappeared as the N‐methyl substitution degree increased. These changes in the morphology resulted (1) in decreased modulus and tensile strength for the films because of the decrease in physical crosslinking points and (2) improved thermal stability as the substitution degree increased. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4077–4083, 2002
Dehydrocoupling and Diels–Alder reactions on siloxane polymers
Authors: Kim Chungkyun , Kwark Kyungran 
Published: October 2002

AbstractDehydrocoupling reactions between linear poly(methylhydrosiloxane) {Me3SiO–[MeSi(H)O]n–SiMe3} and alcohols such as cholesterol, anthracene‐9‐carbinol, (12‐crown‐4)‐2‐carbinol, pyrene‐1‐carbinol, 4‐methyl‐5‐thiazoleethanol, and 4‐pyridilpropanol were introduced under catalytically mild conditions. The degrees of conversion of SiH bonds in polysiloxane were monitored with 1H NMR spectra. The reaction of the 9‐methoxyanthracene adduct on siloxane polymers and maleimide derivatives (maleimide, N‐ethylmaleimide, and maleic acid anhydride) produced [2+4]‐cycloadducts in very high yields. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4013–4019, 2002
Structural polymorphism in poly(dodecamethylen‐di‐O‐methyl‐L‐tartaramide)
Authors: Iribarren Laco José Ignacio 
Published: October 2002

AbstractStructural characterization of poly(dodecamethylen‐di‐O‐methyl‐L‐tartaramide) was carried out with optical microscopy, thermal analysis, X‐ray diffraction, and electron microscopy. Two different crystalline forms were found in accordance with the thermograms, powder and fiber X‐ray diffraction diagrams. The electron microscopy allows corroboration of the morphological and crystallographic differences. Molecular modeling was used to conclude the structural analogies and differences between the two crystalline forms that were related to the chain packing and orientation in the crystal cell, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2523–2530, 2002
Persistent pulmonary interstitial emphysema in an unventilated neonate
Authors: Gürakan Berkan , Tarcan Aylin , Arda Irfan Serdar , Coşkun Mehmet 
Published: October 2002

AbstractPersistent pulmonary interstitial emphysema (PPIE) is a chronic form of pulmonary interstitial emphysema. The disease is histologically distinguished by large cysts and giant cells. Our patient was a female twin who was born at 31 weeks of gestation with a birth weight of 1,450 g. A chest X‐ray at 2 hr after delivery was normal. At 12 hr, respiratory distress developed, and nasal continuous positive airway pressure (CPAP) was initiated. A chest film revealed left‐sided pneumothorax. A chest tube was inserted, and the baby continued on nasal CPAP for 5 days. Her chest X‐ray on postnatal day 4 showed diffuse cystic changes in the left lung. Thoracic computed tomography revealed multiple thick‐walled cysts, the largest measuring 3 cm in diameter. Our case confirms that localized PIE may occur in preterm infants who have been treated with nasal CPAP only. Since this method is being used increasingly to avoid mechanical ventilation and in the postextubation period, it is very important that clinicians be aware of its complications. Pediatr Pulmonol. 2002; 34:409–411. © 2002 Wiley‐Liss, Inc.