bluuebunny/crossref_metadata_2025_split huggingface dataset:
Issues and methodological challenges in developing and evaluating health care interventions for older people with diabetes mellitus – part 2
Authors: Forbes A , Berry J , While A , Hitman GA , Sinclair AJ 
Published: August 2002

AbstractThis review discusses a number of different issues relating to the development and evaluation of interventions for the diabetes care of older people. The review draws on the experience of a pilot study examining a new model of care for older frail people with type 2 diabetes, which comprised a specially developed clinical protocol to support district nurses in carrying out a diabetic annual review for the ‘older housebound’. The review examines the difficulties encountered in conducting research with this vulnerable subset of the population of people with diabetes and suggests how they may be overcome. Particular attention is directed at clarifying the research population, the validity of the proposed intervention, alternative approaches to the care of the older population with diabetes, sample selection and recruitment, and outcome measures. Copyright © 2002 John Wiley & Sons, Ltd.
Interaction of main‐chain polycations with sodium dodecyl sulfate
Authors: Zheng Xiaoliang , Cao Weixiao 
Published: August 2002

AbstractThe interaction of the main‐chain polycations 2,2‐ionene (I2,2) and 3,3‐ionene (I3,3) with sodium dodecyl sulfate (SDS) has been investigated in aqueous solution. It was confirmed that the interaction is cooperative and a stoichiometric 1:1 complex of I2,2–SDS or I3,3–SDS with regular structure forms as a precipitate irrespective of the molar ratio of the components. It is completely different from the interaction of side‐chain polycations such as the poly[(vinyl pyridine)‐co‐styrene] copolymer cation (PVSC) with SDS, in which no cooperative effect was observed. The driving force responsible for the cooperative effect is believed to be the hydrophobic attraction between the SDS molecule already linked on the ionene chain and the next SDS molecule to be entered. It was also confirmed that the structures of the complexes are very different, ie the ionene–SDS complexes exhibit high regularity whereas the PVSC–SDS complex is irregular.© 2001 Society of Chemical Industry
Basic characterization of polypropene‐block‐poly(methylene‐1,3‐cyclopentane‐co‐propene) synthesized from propene and 1,5‐hexadiene with modified stopped‐flow method
Authors: Kono Hiroyuki , Ichiki Tomohito , Mori Hideharu , Nakatani Hisayuki , Terano Minoru 
Published: August 2002

AbstractBlock copolymerization of propene and 1,5‐hexadiene was carried out by a modified stopped‐flow polymerization method with an MgCl2‐supported Ziegler catalyst. The resulting polymer, polypropene‐block‐poly(methylene‐1,3‐cyclopentane‐co‐propene) (PP‐b‐(PMCP‐co‐PP)), in which the crystallizable PP part was linked with the non‐crystallizable PMCP‐co‐PP part, was characterized by optical microscopy, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and tensile testing. The block copolymer having a chemical linkage between PP and PMCP‐co‐PP showed properties different from those of homopolymer, random copolymer and blend polymer.© 2001 Society of Chemical Industry
Syntheses, antitumour activities and antiangiogenesis of 1,2,3‐tris(ethoxycarbonyl)‐2‐propyl acrylate and its polymers
Authors: Kim Min‐Jeong , Chung Il‐Doo , Lee Sun‐Mi , Kim Seon‐Hee , Ha Chang‐Sik , Cho Won‐Jei 
Published: August 2002

AbstractA new monomer, 1,2,3‐tris(ethoxycarbonyl)‐2‐propyl acrylate (TPA), was synthesized by reaction of acryloyl chloride and triethyl citrate. The homopolymer of TPA and its copolymers with acrylic acid (AA), vinyl acetate (VAc) and maleic anhydride (MAH) were prepared by polymerization using lauroyl peroxide (LPO) at 70 °C for 24 h. The structures of TPA and its polymers were identified by FTIR, 1H NMR, 13C NMR spectroscopies, and elemental analysis. The number average molecular weights and polydispersity indices of the synthesized polymers determined by GPC were in the range 4200–23 000 g mol−1 and 1.1–2.1, respectively. The IC50 values of the synthesized samples against cancer cell lines were greater than those of 5‐fluorouracil (5‐FU). The percentage inhibition values of SV40 DNA replication were 82.2 for TPA, 34.3 for poly (TPA), 81.9 for poly(TPA‐co‐AA), 82.0 for poly(TPA‐co‐VAc), 35.6 for poly(TPA‐co‐MAH) and 12.7 for 5‐FU. The inhibitions of SV40 DNA replication and antiangiogenesis for the synthesized TPA and its polymers are much greater than those of the control.© 2001 Society of Chemical Industry
Copolymerization of methyl methacrylate and allyl acetate Part I. Rate of reaction
Authors: Hendrana Sunit , Hill David J T , Senake Perera M C , Pomery Peter J 
Published: August 2002

AbstractFree radical bulk copolymerization of methyl methacrylate (MMA) and allyl acetate (AAc) has been investigated using electron spin resonance (ESR) and FT–near infrared (FTNIR) spectroscopy. Data are used to evaluate the rate constants. The mole fraction of AAc plays an important role in the copolymerization of these two monomers. AAc not only delays the Trommsdorff effect but also increases the onset of percentage total conversion at which the Trommsdorff region begins. With AAc fraction 0.5 and higher, no Trommsdorff effect was observed. Inclusion of AAc into copolymer structure mainly occurs in the Trommsdorf region or when the AAc fraction in the comonomer feed is dominant. This is associated with a drop in the concentration of propagating radicals. However, ESR spectra indicate that the MMA propagating radical is predominant during the reaction. In the comonomer mixtures where a Trommsdorff region can be observed, the addition of AAc does not produce any significant change in kp and kt in the steady state region. Major changes in kp and kt are observed after the gel point and glassy state, respectively.© 2001 Society of Chemical Industry
Aqueous poly(urethane–urea) dispersions and cast films based on m‐TMXDL. 1. Structure–property relationships
Authors: Lahtinen Mika , Price Colin 
Published: August 2002

AbstractAqueous poly(urethane–urea) dispersions were prepared from polycaprolactone diol, α,α,α′,α′‐tetramethyl‐1,3‐xylylene diisocyanate (m‐TMXDI) and α,α‐dimethylol propionic acid (DMPA) using a prepolymer mixing process. In the process, polyurethane prepolymers were neutralised with triethylamine and the chains extended in water with either hydrazine, 1,2‐ethylene diamine or 1,2‐propylene diamine. For comparison, some samples were prepared from a more commonly used diisocyanate, isophorone diisocyanate (IPDI). Dispersion characteristics and basic structure–property relationships of the cast films were determined. m‐TMXDI provided some advantages over IPDI in the preparations since its use gave lower prepolymer viscosities and better resistance to elevated temperatures. Films prepared from m‐TMXDI dispersions exhibited considerably lower values of Young's modulus and hardness and higher elongations at break than those prepared from IPDI‐based dispersions for analogous compositions, whereas differences in the average particle sizes or viscosities of the dispersions were only small. When the DMA content was varied, the dispersions and cast films of m‐TMXDI‐based systems showed similar changes as are known to occur in IPDI‐based systems: as the DMPA content was increased, the average particle size of the dispersions decreased and the viscosity increased, and for the cast films, the Young's modulus and tensile strength increased and the maximum elongation at break decreased. Changing the chain‐extension agent from hydrazine to 1,2‐ethylene diamine, to 1,2‐propylene diamine and had little effect on the particle size of the dispersions, but increased the Young's modulus and hardness of the respective cast films. Molar masses of the chain‐extended polymers were unexpectedly low. DSC analysis of cast films indicated that the degree of crystallisation of the soft or hard domains was low.© 2002 Society of Chemical Industry
Long‐range substituent and temperature effect on prototropic tautomerism in 2‐(acylmethyl)quinolines
Authors: Gawinecki Ryszard , Ośmiałowski Borys , Kolehmainen Erkki , Kauppinen Reijo 
Published: August 2002

AbstractTautomeric equilibria between 2‐(cinnamoylmethyl)quinoline, (Z)‐1,2‐dihydro‐2‐(cinnamoylmethylene)quinoline and (Z)‐4‐phenyl‐1‐(2‐quinolyl)‐1,3‐butadien‐2‐ol were studied by 1H, 13C and 15N NMR methods. The —CHCH— fragment conjugated with phenyl and a strong electron donor p‐(1‐pyrrolidine) substituent were found to favour the enolimine tautomer. This undergoes fast exchange (on the NMR time‐scale) with the enaminone form. The amount of the latter tautomer was found to increase at low temperatures. Copyright © 2001 John Wiley & Sons, Ltd.
Theoretical investigations on bond enthalpy additivity deviations in the formation of triplet diradicals from hetero‐substituted 1,3‐dimethylenecyclobutanes
Authors: Zhang Daisy Y. 
Published: August 2002

AbstractIn our continuing effort to understand better the cause of the large positive deviation from bond enthalpy additivity (BEA) observed in the formation of triplet 1,3‐dimethylenecyclobutane‐2,4‐diyl (1c) from 1,3‐dimethylenecyclobutane (1a), we performed B3LYP/6–31G* calculations on a series of 1,3‐disubstituted cyclobutanes, where the methylene groups in 1a are replaced by hetero groups, specifically O, NH, S, PH and SiH2. The size of the deviation from BEA (ΔBEA) is found to increase consistently with decreasing bond strength of the exocyclic π bonds. DFT calculations were also carried out on related hydrocarbons and the ΔBEA value in each case was found to be in close agreement with that predicted by simple Hückel theory. All of the computational results provide convincing evidence that antiaromaticity is absent in these diradicals, and the positive deviations from BEA, as large as 30.3 kcal mol−1, are due to the more substantial increase in the π electron delocalization in the monoradicals than that in the diradicals. Copyright © 2001 John Wiley & Sons, Ltd.
O‐Phosphorylated calix[4]arenes as Li+‐selective­receptors
Authors: Lukin, Oleg , Vysotsky Myroslav O. , Kalchenko* Vitaly I. 
Published: August 2002

AbstractPhosphorylation of p‐tert‐butylcalix[4]arene 9 or calix[4]arene 10, having two diethoxyphosphoryl groups at distal positions on their narrow rim (phenolic oxygen atoms), by dibutyloxophosphinechloride or alkylation of 10 by methyl bromoacetate led to the corresponding tetrasubstituted calix[4]arenes 8b–d fixed in a cone conformation. The latter compounds and the similar derivative of calix[4]arene 8a with four diethoxyphosphoryl groups were found to exhibit lithium cation selectivity, which was supported by UV–Vis spectra of THF solutions of the alkali metal picrates and their water–chloroform extraction in the presence of ligands 8a–d. Calculated K/K selectivities range from 2.9 (8d) to 9.5 (8a), which are among the highest values for the calixarene‐based Li+‐selective receptors reported to date. Copyright © 2001 John Wiley & Sons, Ltd.
Mechanism and proton activating factors in the base‐induced β‐elimination reaction of N‐[2‐(2‐quinolyl)ethyl]quinuclidinium salt
Authors: Alunni S. , Orazi C. 
Published: August 2002

AbstractN‐[2‐(2‐Quinolyl)ethyl]quinuclidinium salt in OH−–H2O, 50 °C, µ = 1 M KCl undergoes an elimination reaction with formation of 2‐vinylquinoline; the second‐order rate constant is kNOH = 12.8 × 10−3 dm3 mol−1 s−1. In acetohydroxamic acid–acetohydroxamate buffers at pH 8–9 the β‐elimination reaction occurs by a reversible E1cb mechanism, (E1cb)R. In this process, carbon deprotonation occurs from the conjugate acid, protonated at the nitrogen atom of the quinoline ring, NH+; this species is present at a very low concentration with respect to the unprotonated substrate N, with pKa = 3.87 at 50 °C, µ = 1 M KCl. The reason for the high reactivity of NH+ with respect to N is related to the high stability of the intermediate carbanion formed from NH+, which presents an enamine structure. Kinetic parameters from a study of acid–base catalysis can be calculated and compared with those of the related system activated by a pyridine ring. Studies of H/D exchange and solvent isotope effect are in agreement with the proposed mechanism. Copyright © 2001 John Wiley & Sons, Ltd.
Multisensitive polymers based on 2‐vinylpyridine and N‐isopropylacrylamide *
Authors: Wohlrab Sebastian , Kuckling Dirk 
Published: August 2002

AbstractPoly(2‐vinylpyridine) (P2VP) containing functionalized end groups was synthesized using nitroxyl‐mediated radical polymerization with a hydroxy‐functionalized stable free radical. It was shown that P2VP could be synthesized with variable molar masses and low polydispersities. The transformation of the hydroxy groups to an acrylic ester led to the formation of macromonomers. A free‐radical copolymerization of these macromonomers with N‐isopropylacrylamide gave a graft copolymer with a poly(N‐ispopropylacrylamide) backbone and P2VP side chains. Polymers containing different amounts of the monomers were synthesized. It was possible to vary both the amount of P2VP side chains at a constant chain length of the macromonomer and the chain length at a nearly constant chain number. The behavior of the multifunctional macromolecules at different temperatures and pH values was investigated using dynamic light scattering and DSC. The macromolecules were found to retain the specific properties of the homopolymers. The hydrodynamic radii of the synthesized graft copolymers were both dependent on the temperature and pH value. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3797–3804, 2001
Synthesis and characterization of high molecular weight atactic polybutene‐1 with a monotitanocene/methylaluminoxane catalyst system
Authors: Huang Qigu , Wu Qing , Zhu Fangming , Lin Shangan 
Published: August 2002

AbstractA novel catalyst precursor, the monotitanocene (η5‐pentamethylcyclopentadienyl) titanium tricinnamyloxide [Cp*Ti(OCH2CHCHC6H5)3], was synthesized and employed for butene‐1 polymerization in the presence of methylaluminoxane. The effects of the polymerization conditions on the catalytic activity, molecular weight, stereoregularity, and regioregularity of the polymer so obtained were investigated in detail. The results show that the monotitanocene is desirable for the production of atactic polybutene‐1 coupled with good yields under typical polymerization conditions, high molecular weight (weight‐average molecular weight = 5.3–9.6 × 105), and stereoirregularity with the Bernoullian factor B equal to 0.95, which indicates that chain‐end control is predominant. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4068–4073, 2001
Functional polyesters prepared by polymerization of α‐allyl(valerolactone) and its copolymerization with ε‐caprolactone and δ‐valerolactone
Authors: Parrish Bryan , Quansah Jennifer K. , Emrick Todd 
Published: August 2002

AbstractWe report the ring‐opening homopolymerization of α‐allyl(valerolactone), compound 2, and its copolymerization with ε‐caprolactone and δ‐valerolactone using stannous(II) catalysis. Although the polymerization of substituted δ‐valerolactones has received little attention for the preparation of functional polyesters, we found that compound 2 may be incorporated in controllable amounts into copolymers with other lactones, or simply homopolymerized to give a highly functionalized, novel poly(valerolactone). The presence of the pendant allyl substituent had a substantial impact on the thermal properties of these materials relative to conventional polyesters prepared from lactones, and most of the polymers presented here are liquids at room temperature. Dihydroxylation of the pendant allyl groups gave polyesters with increased hydrophilicity that degraded more or less rapidly depending on their extent of functionality. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1983–1990, 2002
Star‐shaped and photocrosslinked poly(1,5‐dioxepan‐2‐one): Synthesis and characterization
Authors: Ryner Maria , Valdre Alexandra , Albertsson Ann‐Christine 
Published: August 2002

AbstractNew star‐shaped and photocrosslinked poly(1,5‐dioxepan‐2‐one) (PDXO) has been synthesized through ring‐opening polymerization initiated by SnOct2/pentaerythritol. The star‐shaped PDXO was end‐functionalized by acrolyol chloride to form acrylate end groups. The end‐functionalized PDXO was photocrosslinked initiated by 2,2‐dimethoxy‐2‐phenylacetophenone. The gel content ranged from 80 to 99%, indicating a high degree of crosslinking. The thermal properties of the star‐shaped PDXO and the photocrosslinked PDXO were analyzed by differential scanning calorimetry. The glass‐transition temperature was determined to approximately −32 °C for the crosslinked PDXO. The viscosity numbers were determined for star‐shaped PDXO, with reference to linear homologues. The star‐shaped PDXO had lower viscosity numbers than the linear counterparts. The crosslinked PDXO showed a rather hydrophilic surface as compared with other resorbable polyesters. The advancing contact angle was 64 ± 2, and the receding angle was 57 ± 4. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2049–2054, 2002
MALDI‐TOF‐MS analysis of living cationic polymerization of vinyl ethers. III. Polymerization with SnCl4 and TiCl4 in the absence of additives
Authors: Katayama Hiroshi , Kamigaito Masami , Sawamoto Mitsuo 
Published: August 2002

AbstractMatrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analysis revealed that the precision control (or the living nature) of the cationic polymerization of vinyl ethers with SnCl4 or TiCl4 critically depends on the Lewis acid concentration and temperature. Specifically, at an extremely low Lewis acid concentration, for example, the polymerization with the HCl–vinyl ether adduct (an initiator) is living at −78 °C in CH2Cl2 solvent, whereas side reactions occurred at a higher concentration of SnCl4 or at a higher temperature, −15 °C. This was more pronounced with SnCl4 than with TiCl4, which was due to a stronger Lewis acidity of SnCl4 as suggested by NMR analysis of the model reactions. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1258–1267, 2001
Synthesis and specific biodegradation of novel polyesteramides containing amino acid residues
Authors: Fan Yujiang , Kobayashi Masami , Kise Hideo 
Published: August 2002

AbstractNovel polyesteramides were synthesized from p‐nitrophenyl esters of sebacic or adipic acids and diamines containing α‐amino acid ester groups. The optimal polymerization condition was 60 °C in N,N‐dimethylformamide. The structures of these polymers were confirmed by IR and NMR. The number‐average molecular weights of these polyesteramides ranged from 2280 to 23,600 (except for the polymers containing glycine residues), depending on the nature of the amino acid used. The biodegradability of the polyesteramides was investigated by in vitro hydrolysis with proteases and a lipase as catalysts in borate buffer solutions. The results indicated that the polymers containing L‐phenylalanine were hydrolyzed most effectively by α‐chymotrypsin, subtilisin Carlsberg, and subtilisin BPN′. The polyesteramides containing other amino acid residues also underwent hydrolysis to different extents, reflecting the substrate specificity of the proteases. Lipase had almost no effect on the hydrolytic degradation of these polyesteramides. The polymers containing glycine residues were hardly decomposed by any of the enzymes used. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1318–1328, 2001
Design and synthesis of highly reactive photopolymerizable epoxy monomers
Authors: Crivello James V. , Ortiz Ricardo Acosta 
Published: August 2002

AbstractThe synthesis of a series of novel cationically photopolymerizable epoxide monomers bearing benzyl, allyl, and propargyl acetal and ether groups that can stabilize free radicals was carried out. These monomers display enhanced reactivity in cationic photopolymerization in the presence of certain onium salt photoinitiators. Specifically, this article describes schemes for the synthesis of cycloaliphatic epoxy monomers bearing free‐radical stabilizing groups. During UV irradiation of an onium salt cationic photoinitiator, the aryl radicals that are generated abstract labile protons present in such monomers to generate the corresponding carbon‐centered radicals. Subsequently, these radicals can interact with the onium salt by a redox mechanism to induce the decomposition of these salts. The overall result is that additional cationic species are generated by this mechanism that increase the rate and extent of the cationic ring‐opening polymerization of the epoxide monomer. An investigation of the photopolymerizations of the monomers prepared during this work was carried out using Fourier transform real‐time infrared spectroscopy, and conclusions were drawn with respect to the relationship between their structures and reactivity. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2385–2395, 2001
Synthesis and characterization of new soluble cardo polyesters derived from 1,1‐bis‐[4‐(4‐chlorocarboxyphenoxy)phenyl]‐4‐tert‐butylcyclohexane with various bisphenols by solution polycondensation
Authors: Liaw Der‐Jang , Hsu Jun‐Jang , Liaw Been‐Yang 
Published: August 2002

AbstractA new cardo diacid chloride, 1,1‐bis‐[4‐(4‐chlorocarboxyphenoxy)phenyl]‐4‐tert‐butylcyclohexane (4), was synthesized from 1,1‐bis‐[4‐(4‐carboxyphenoxy)phenyl]‐4‐tert‐butylcyclohexane in refluxing thionyl chloride. Subsequently, various new polyesters were prepared from 4 with various bisphenols by solution polycondensation in nitrobenzene using pyridine as a hydrogen chloride quencher at 150 °C. These polyesters were produced with inherent viscosities of 0.32–0.50 dL · g−1. Most of these polyesters exhibited excellent solubility in a variety of solvents such as N,N‐dimethylformamide, tetrahydrofuran, tetrachloroethane, dimethyl sulfoxide, N,N‐dimethylacetamide, N‐methyl‐2‐pyrrolidinone, m‐cresol, o‐chlorophenol, and chloroform. These polymers showed glass‐transition temperatures (Tg's) between 144 and 197 °C. The polymer containing the adamantane group exhibited the highest Tg value. The 10% weight loss temperatures of the polyesters, measured by thermogravimetric analysis, were found to be in the range of 426–451 °C in nitrogen. These cardo polyesters exhibited higher Tg's and better solubility than bisphenol A‐based polyesters. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2951–2956, 2001
Synthesis and characterization of aromatic cyclolinear phosphazene polyetherketones containing bis‐Spiro‐substituted cyclotriphosphazene unit
Authors: Tunca Umit , Erdogmus Ali , Hizal Gurkan 
Published: August 2002

AbstractA novel monomer, 2,2‐bis‐(4′‐fluorobenzoylphenoxy)‐4,4,6,6‐bis[spiro‐(2′,2″‐dioxy‐1′, 1′‐biphenylyl)] cyclotriphosphazene, was synthesized and polymerized with 4,4′‐difluorobenzophenone as a comonomer and 4,4′‐isopropylidenediphenol or 4,4′‐(hexafluoroisopropylidene) diphenol in N,N‐dimethylacetamide at 162 °C for 4 h to give two series of aromatic cyclolinear phosphazene polyetherketones containing bis‐spiro‐substituted cyclotriphosphazene groups. The structure of the monomer was confirmed by 1H, 13C, and 31P NMR. The effect of the incorporation of the bis‐spiro‐substituted cyclotriphosphazene group on the thermal properties of these polymers was investigated by DSC and thermogravimetric analysis. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2993–2997, 2001