bluuebunny/crossref_metadata_2025_split huggingface dataset:
Curing of an epoxy resin modified with nanoclay monitored by dielectric spectroscopy and rheological measurements
Authors: Kortaberria G. , Solar L. , Jimeno A. , Arruti P. , Gómez C. , Mondragon I. 
Published: September 2006

AbstractDielectric and rheological measurements have been performed in “real‐time” to follow curing reaction on blends of a diglycidyl ether of bisphenol‐A epoxy resin with 4,4‐methylene bis(2,6‐diethylaniline) hardener and different amounts of organically modified nanoclay (Nanofil 919) as modifier. The effect of the modifier and its amount on the curing reaction, as well as that of the curing temperature has been studied. Changes in molecular mobility in the reaction mixture have been investigated by dielectric relaxation spectroscopy. Evolutions of ionic conductivity and main relaxation have been analyzed and vitrification times have been obtained and compared with those obtained by rheological measurements. The relaxational behavior has been analyzed through curing in the frequency domain, being the displacement of the main relaxation indicative of the cure reaction advancement. Gelation and vitrification times for the nanocomposite systems have been found to be lower than for the neat resins, indicating a catalytic effect of the clays on the curing reaction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5927–5933, 2006
Synthesis and characterization of isocyanic acid, m‐phenylenediiso‐propylidene based poly(urethane‐urea) dispersions containing different amount of 2,2‐Bis(hydroxyl methyl)propionic acid
Authors: Chiu Hsien‐Tang , Huang Yi‐Chin , Hu Hsiu‐Yeh 
Published: September 2006

AbstractIsocyanic acid, m‐phenylenediiso‐propylidene (m‐TMXDI)‐based anionic poly(urethane‐urea) dispersions were prepared by the prepolymer mixing process. The equivalent ratio of NCO/OH was kept constant at 1.8, while 2,2‐bis(hydroxyl methyl) propionic acid (DMPA) used was varied from 3 to 10 wt %. The colloidal stability of poly(urethane‐urea) dispersions arose entirely from the presence of ionized carboxylic acid groups. The chemical structure of poly(urethane‐urea) dispersions with various amount of DMPA were identified by FTIR and 13C NMR analysis. The test results showed that the hydrophilicity of poly(urethane‐urea) dispersions were increased with increase in DMPA content. The degree of chain extension was much lower than the values predicted theoretically due to the side reaction of a small amount of hydrophilic isocyanate‐terminated prepolymer with water. The average particle size of poly(urethane‐urea) dispersions were decreased with an increase in DMPA content, and this lead to an increase in viscosity. Also, the thermal degradation behavior were measured and was shown that the initial degradation temperature shifted to lower temperature with an increase in DMPA content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5737–5746, 2006
Methanol permeability and properties of DMFC membranes based on sulfonated PEEK/PVDF blends
Authors: Wootthikanokkhan J. , Seeponkai N. 
Published: September 2006

AbstractProton exchange membranes for a direct methanol fuel cell were prepared by blending poly(vinylidene fluoride) [PVDF] with sulfonated poly(etheretherketone) [SPEEK]. The effects of PVDF content on methanol permeability in the blend membranes were investigated by using a diffusion cell and gas chromatography technique. The thermal resistance and proton conductivity of the membranes were also determined by using a thermal gravimetric analysis (TGA) and an impedance analysis technique, respectively. It was found that methanol permeability in the blend membranes decreased with PVDF content at the expense of proton conductivity. The methanol permeability values of the blend membranes are much lower than that of Nafion 115, whereas proton conductivities of the membranes are comparable to that of Nafion. The thermal stability of these blend membranes are above 250°C which is sufficiently high for use in DMFC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5941–5947, 2006
Influence of high density polyethylene‐g‐maleic anhydride on compatibility and properties of poly(butylene terephthalate)/high density polyethylene blends
Authors: Qi Rongrong , Nie Jinghui , Zhou Chixing , Mao Dalian , Zhang Bian 
Published: September 2006

AbstractPoly(butylene terephthalate)/high density polyethylene (PBT/HDPE) blends and PBT/HDPE‐grafted maleic anhydride (PBT/HDPE‐g‐MAH) blends were prepared by the reactive extrusion approach, and the effect of blend compositions on the morphologies and properties of PBT/HDPE blends and PBT/HDPE‐g‐MAH blends was studied in detail. The results showed that flexural strength, tensile strength, and notched impact strength of PBT/HDPE blends decreased with the addition of HDPE, and flexural strength and tensile strength of PBT/HDPE‐g‐MAH blends decreased, while the notched impact strength of PBT/HDPE‐g‐MAH increased with the addition of HDPE‐g‐MAH. Compared with PBT/HDPE blends, the dimension of the dispersed phase particles in PBT/HDPE‐g‐MAH blends was decreased and the interfacial adhesion was increased. On the other hand, the effects of HDPE and HDPE‐g‐MAH contents on the crystalline and the rheological properties of the blends were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6081–6087, 2006
Evaluation of some of the properties of plasma treated wool fabric
Authors: Kan C. W. , Yuen C. W. M. 
Published: September 2006

AbstractLow temperature plasma (LTP) treatment was applied to wool fabric with the use of a nonpolymerizing gas, namely oxygen. Properties of the LTP‐treated samples including low stress mechanical behavior, air permeability, and thermal characteristics were evaluated in this study. Kawabata evaluation system fabric (KES‐F) was employed to determine the tensile, shearing, bending, and compression strength properties and surface roughness of the specimens. The changes in these properties are believed to be closely related to the interfiber and interyarn frictional force induced by the LTP. The decrease in the air permeability of the LTP‐treated wool fabric was found to be probably because of the plasma action effect on increasing the fabric thickness and a change in fabric surface morphology, which was confirmed by scanning electron microscopy micrographs. The change in the thermal properties of the LTP‐treated wool fabric was in good agreement with the earlier findings and can be attributed to the amount of air trapped between the yarns and fibers. This study suggested that the LTP treatment can influence the final properties of the wool fabric, and also provide information for developing LTP‐treated wool fabric for industrial use. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5958–5964, 2006
A very simple empirical kinetic model of the acid‐catalyzed cure of urea–formaldehyde resins
Authors: Carvalho Luisa M. H. , Costa Mário Rui P. F. N. , Costa Carlos A. V. 
Published: September 2006

AbstractThe hot pressing operation is the final stage in MDF (medium density fiberboard) manufacture; the fiber mat is compressed and heated up to promote the cure of the resin. The aim of the investigations is to study the curing reactions of UF (Urea–Formaldehyde) resins as commonly used in the production of MDF, and to develop a simplified kinetic model. This investigation has combined Raman spectroscopy to study the reaction cure and 13C‐NMR for the quantitative and qualitative characterization of the liquid and still uncured resin. Raman spectroscopy was found very interesting for the study of the resin cure and permitted to obtain kinetic data as the basis for a simple empirical model, considering a homogeneous irreversible reaction of a single kind of methylol group and ureas with rate constants depending on their degree of substitution. Although these results can provide a better understanding of the composition and the cure of an UF resin, several issues remain open, such as the influence of the reversibility of the reactions taking place during the curing process as well as the possible formation of cyclic groups in the resin. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5977–5987, 2006
Reorganization of the chain packing between poly(ethylene isophthalate) chains via coalescence from their inclusion compound formed with γ‐cyclodextrin
Authors: Pang Kyeong , Schmidt Ben , Kotek Richard , Tonelli Alan 
Published: September 2006

AbstractAmorphous poly(ethylene isophthalate) (PEI) was synthesized, and was used for preparing an inclusion compound (IC) with γ‐cyclodextrin (γ‐CD). Coalesced polymer was produced by washing the PEI‐γ‐CD‐IC with hot water. Wide angle X‐ray diffraction, Fourier transform infrared, and differential scanning calorimetry analyses were employed to verify formation of PEI‐γ‐CD‐IC and to compare the as‐synthesized and coalesced PEI samples. These observations suggested that the conformations and morphology/chain‐packing of PEI were changed via coalescence from its γ‐CD inclusion compound. The glass‐transition temperature of the amorphous coalesced PEI is 15–20°C higher than the Tg observed for the as‐synthesized sample, even when observed in the second heat after cooling from well above Tg at 260°C. The amorphous as‐synthesized PEI retains its randomly‐coiling structure, while coalesced PEI has at least partially retained, the highly extended and parallel chains from the narrow channels of the inclusion compound, resulting in better/tighter packing among the PEI chains manifested by a higher Tg. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6049–6053, 2006
Synthesis of nanostructured large particles of polyaniline
Authors: Eftekhari Ali 
Published: September 2006

AbstractSynthesis of larger particles of conductive polymers is usually favorable due to higher conductivity (as a result of lesser interfacial resistance). On the other hand, advantages of nanostructured materials are well known. Thus, it is desirable to fabricate large particles that have nanostructure, to gain double advantage. A simple method based on chemical polymerization under centrifugal forces is proposed to achieve this goal. It was typically employed for a well‐known conductive polymer, namely, polyaniline to fabricate large particles (e.g., 400 μm) with internal nanostructure of ∼100 nm. This also significantly increases the electrical conductivity of the polymer. This is indeed a simple approach, which can be easily performed using a conventional centrifuge system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6060–6063, 2006
Synthesis and Aldose Reductase Inhibitory Activities of Novel O‐Substituted Hydroxyphenylacetic Acid Derivatives
Authors: Rakowitz Dietmar , Angerer Helga , Matuszczak Barbara 
Published: September 2006

AbstractIn continuation of our work aimed towards the preparation of novel aldose reductase inhibitors, several O‐substituted hydroxyphenylacetic acid derivatives were investigated. The highest inhibitory activity was found for compounds 7b and 7c bearing a cyclohexylmethyl substituent. This result demonstrates that within these series, this moiety is a useful surrogate for the 4‐bromo‐2‐fluorobenzyl residue which can be often found in potent aldose reductase inhibitors.
IKKβ inhibition protects against bone and cartilage destruction in a rat model of rheumatoid arthritis
Authors: Schopf Lisa , Savinainen Anneli , Anderson Karen , Kujawa Julie , DuPont Michelle , Silva Matthew , Siebert Elizabeth , Chandra Sudeep , Morgan Jennifer , Gangurde Pranoti , Wen Danyi , Lane Joan , Xu Yajun , Hepperle Michael , Harriman Geraldine , Ocain Timothy , Jaffee Bruce 
Published: September 2006

AbstractObjectiveThe IKK complex regulates NF‐κB activation, an important pathway implicated in the rheumatoid arthritis (RA) disease process. This study was undertaken to assess the efficacy of N‐(6‐chloro‐7‐methoxy‐9H‐β‐carbolin‐8‐yl)‐2‐methylnicotinamide (ML120B), a potent and selective small molecule inhibitor of IKKβ.MethodsPolyarthritis was induced in rats by injection of Freund's complete adjuvant into the hind footpad. ML120B was administered orally twice daily, either prophylactically or therapeutically. Paw volumes and body weights were measured every 2–3 days throughout the study. We assessed bone erosions by several methods: histologic evaluation, quantitative micro–computed tomography (micro‐CT) imaging analysis, and measurement of type I collagen fragments in the serum. Quantitative polymerase chain reaction was used to evaluate expression of messenger RNA for genes related to inflammation and to bone and cartilage integrity.ResultsOral administration of ML120B inhibited paw swelling in a dose‐dependent manner (median effective dosage 12 mg/kg twice daily) and offered significant protection against arthritis‐induced weight loss as well as cartilage and bone erosion. We were able to directly demonstrate that NF‐κB activity in arthritic joints was reduced after ML120B administration. Also, we observed that down‐regulation of the NF‐κB pathway via IKKβ inhibition dampened the chronic inflammatory process associated with rat adjuvant‐induced arthritis.ConclusionThe results of the present study suggest that IKKβ inhibition is an effective therapeutic approach to treat both the inflammation and the bone/cartilage destruction observed in RA. Methods for the determination of serum markers for bone and cartilage destruction, as well as micro‐CT analysis, may aid in predicting and evaluating the therapeutic efficacy of IKKβ inhibition therapy in humans.
Clinical assessment of the long‐term risk of fracture in patients with rheumatoid arthritis
Authors: Staa T. P. Van , Geusens P. , Bijlsma J. W. J. , Leufkens H. G. M. , Cooper C. 
Published: September 2006

AbstractObjectiveTo determine whether patients with rheumatoid arthritis (RA) have an increased risk of fracture, and to estimate their long‐term absolute fracture risk.MethodsWe studied patients with RA ages ≥40 years in the British General Practice Research Database, each matched by age, sex, calendar time, and practice to 3 control patients. Incident fractures, as recorded in the computerized medical records, were ascertained over a median followup of 7.6 years. The fracture rate in RA patients compared with controls was adjusted for smoking, body mass index (BMI), and several clinical risk factors, and Cox proportional hazards models were used to calculate the relative risk (RR) of fracture in RA. A risk score was then developed to provide an estimate of the 5‐ and 10‐year fracture risk among RA patients.ResultsThere were 30,262 patients with RA, of whom 2,460 experienced a fracture during followup. Compared with controls, patients with RA had an increased risk of fracture, which was most marked at the hip (RR 2.0, 95% confidence interval [95% CI] 1.8–2.3) and spine (RR 2.4, 95% CI 2.0–2.8). Indicators of a substantially elevated risk of fracture (at the hip) included >10 years' duration of RA (RR 3.4, 95% CI 3.0–3.9), low BMI (RR 3.9, 95% CI 3.1–4.9), and use of oral glucocorticoids (RR 3.4, 95% CI 3.0–4.0). Modeling of the long‐term risk profiles revealed that, for example, in a woman age 65 years with longstanding RA whose risk factors also included low BMI, a history of fracture, and frequent use of oral glucocorticoids, the 5‐year risk of hip fracture was 5.7% (95% CI 5.3–6.1%).ConclusionPatients with RA are at increased risk of osteoporotic fractures. This increased risk is attributable to a combination of disease activity and use of oral glucocorticoids.
Pediatric granulomatous arthritis: An international registry
Authors: Rosé Carlos D. , Wouters Carine H. , Meiorin Silvia , Doyle Trudy M. , Davey Michael P. , Rosenbaum James T. , Martin Tammy M. 
Published: September 2006

AbstractObjectiveBlau syndrome and its sporadic counterpart, early‐onset sarcoidosis, share an identical phenotype featuring the classic triad of arthritis, dermatitis, and uveitis and are associated with mutations of CARD15 in 50–90% of cases. We chose the term “pediatric granulomatous arthritis” to refer to both. An international registry was established in the spring of 2005 to define the phenotype spectrum and establish the mutation frequency and variants.MethodsHistologically confirmed granuloma and arthritis were required for inclusion. Probands and relatives were genotyped for CARD15. Deidentified clinical information was collected.ResultsOne year after the inception of the registry, 61 individuals from 22 pedigrees had been entered. Seven pedigrees with 19 individuals (8 affected, 11 unaffected) had clinical disease that was atypical, and none of the individuals in those pedigrees showed mutations. There were 9 classic simplex pediatric granulomatous arthritis pedigrees including 19 individuals (9 affected, 10 unaffected) and 6 classic multiplex pedigrees with 22 individuals (17 affected, 5 unaffected). Cutaneous presentation was the most common. Arthritis was polyarticular in 96% of patients. Isolated eye disease was never the presenting symptom, but significant/severe visual impairment was observed in 41% of patients. Eye disease was bilateral in 21 of 22 patients and was complicated by glaucoma in 6 of 22 patients and by cataracts in 50% of patients. Skin biopsy was the best diagnostic approach (because of accuracy and low invasiveness).ConclusionIn this series, the first combining familial and sporadic pedigrees and, to our knowledge, the largest, we further defined the phenotype and showed that all affected classic (and no nonclassic) pedigrees carry a mutation and that there is no asymptomatic carriage. If these data are confirmed, mutation analysis rather than tissue sampling may prove to be the most efficient diagnostic procedure.
Pharmacogenomic and metabolic biomarkers in the folate pathway and their association with methotrexate effects during dosage escalation in rheumatoid arthritis
Authors: Dervieux Thierry , Greenstein Neal , Kremer Joel 
Published: September 2006

AbstractObjectiveTo evaluate the contribution of metabolites (methotrexate [MTX] and folate polyglutamate [PG] levels) and pharmacogenetic biomarkers in the folate pathway to the effects of MTX in patients with rheumatoid arthritis not previously treated with this antifolate.MethodsForty‐eight MTX‐naive adult patients were enrolled in a prospective longitudinal study. MTX therapy was initiated at 7.5 mg/week and was increased every 4–6 weeks until a therapeutic response was achieved. Response was assessed using the Disease Activity Score in 28 joints (DAS28). Red blood cell (RBC) MTX and folate PG levels were measured with 9 common polymorphisms in the folate pathway. Statistical analyses consisted of generalized linear models and multivariate regressions.ResultsAfter 6 months of therapy, the median weekly MTX dosage was 17.5 mg and the median decrease in the DAS28 was 2.0. There was a large interpatient variability in RBC MTXPG levels (median 35 nmoles/liter [interquartile range 28–51] at month 6). Patients with a lesser decrease in the DAS28 (fewer improvements) had lower RBC MTXPG levels (P < 0.05) despite the higher MTX dose administered (P < 0.05). RBC folate PG levels decreased significantly during treatment, and a lesser decrease in RBC folate PGs was associated with a lesser decrease in the DAS28 (P < 0.05). Primary side effects were gastrointestinal and neurologic in nature. Risk genotypes associated with toxicity were in γ‐glutamyl hydrolase (−401CC), 5‐aminoimidazole‐4‐carboxamide ribonucleotide transformylase (347GG), methylenetetrahydrofolate reductase (1298AC/CC), methionine synthase (2756AA), and methionine synthase reductase (66GG).ConclusionRBC MTXPG levels are a useful means by which to monitor therapy. The genetic associations presented generate hypotheses, and confirmation in independent cohorts is warranted.
Variability in the efficacy of interferon‐α in Erdheim‐Chester disease by patient and site of involvement: Results in eight patients
Authors: Haroche Julien , Amoura Zahir , Trad Salim G. , Wechsler Bertrand , Cluzel Philippe , Grenier Philippe A. , Piette Jean‐Charles 
Published: September 2006

AbstractObjectiveErdheim‐Chester disease (ECD) is a rare, non‐Langerhans form of histiocytosis of unknown origin, characterized by infiltration of tissues by spumous histiocytes. ECD features heterogeneous systemic manifestations, and the general prognosis remains poor despite various treatment options.MethodsWe treated 8 patients with multisystemic ECD with subcutaneous interferon‐α (IFNα) at a dosage of 3–9 × 106 units 3 times weekly, for a median duration of 23 months (range 1–46 months).ResultsTreatment was generally well tolerated, and side effects remained limited to fever following injections. Treatment was discontinued in 1 patient, because of severe depression. During treatment, some manifestations of ECD disappeared (i.e., xanthelasma, exophthalmos, papilledema, and intracranial hypertension). The efficacy of IFNα on cardiovascular ECD was variable, however. Treatment resulted in partial regression of “coated aorta” in some cases and clear failure in others; 2 patients died. The level of C‐reactive protein diminished sharply in 5 patients.ConclusionIFNα might be a valuable first‐line therapy for prolonged treatment of ECD. However, the efficacy of IFNα varies among patients and according to the sites of disease involvement, and symptoms may fail to respond to treatment, especially in patients with severe multisystemic forms of ECD with central nervous system and cardiovascular involvement.
An Environmentally Benign Process for the Hydrogenation of Ketones with Homogeneous Iron Catalysts
Authors: Enthaler Stephan , Hagemann Bernhard , Erre Giulia , Junge Kathrin , Beller Matthias 
Published: September 2006

AbstractIron complexes generated in situ catalyze homogeneously the transfer hydrogenation of aliphatic and aromatic ketones by utilizing 2‐propanol as a hydrogen donor in the presence of base. The influence of different reaction parameters on the catalytic activity is investigated in detail by applying a three‐component catalyst system composed of an iron salt, 2,2′:6′,2′′‐terpyridine, and PPh3. The scope and limitations of the described catalyst is shown in the reduction of 11 different ketones. In most cases, high conversion and excellent chemoselectivity are obtained. Mechanistic studies indicate a monohydride reaction pathway for the homogeneous iron catalyst.
Ring‐Closing Olefin Metathesis for the Synthesis of Benzene Derivatives
Authors: Yoshida Kazuhiro , Kawagoe Fumihiro , Iwadate Noriyuki , Takahashi Hidetoshi , Imamoto Tsuneo 
Published: September 2006

AbstractBenzene derivatives were synthesized in excellent yield from 1,4,7‐trien‐3‐ols by tandem ruthenium‐catalyzed ring‐closing olefin metathesis (RCM)/dehydration. The method was extended to the tandem RCM/oxidation process to obtain phenol and aniline derivatives. This method displays many advantages over aromatic‐substitution‐based classical routes.