bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of cyclooxygenase isoforms in normal human skin and chronic venous ulcers
Authors: Abd‐El‐Aleem Seham A. , Ferguson Mark W. J. , Appleton Ian , Bhowmick Arnab , McCollum Charles N. , Ireland Grenham W. 
Published: August 2002

AbstractChronic venous ulcers are an example of abnormal wound healing showing chronic inflammation which together with the underlying vascular pathology results in delayed healing. Prostaglandins are among the most important mediators of inflammation. They have proinflammatory effects, predominantly by affecting the vasculature. Cyclooxygenase (COX) is the rate‐limiting enzyme in prostanoid synthesis. It is present in two isoforms: COX‐1 (constitutive cyclooxygenase) which is produced in the body to maintain normal haemostatic functions, and COX‐2 (inducible cyclooxygenase), which is induced during inflammation in response to cytokines. Using immunoenzymatic labelling and western blot analysis, this study has shown that both COX‐1 and COX‐2 were up‐regulated in chronic venous leg ulcers by comparison with normal human skin. De novo appearance of COX‐2 in chronic venous ulcers was demonstrated, which is not seen in normal human skin. The main cellular sources of both COX isoforms are macrophages and endothelial cells. COX‐2 is also produced by mast cells and fibroblasts. A COX radioimmunoassay showed up‐regulation of COX activity in chronic venous ulcers compared with normal skin (p<0.05). Up‐regulation of COX‐1 in chronic venous leg ulcers could produce prostacyclin, which contributes to angiogenesis. Thus, inhibition of COX‐1 by non‐steroidal anti‐inflammatory drugs (NSAIDs) could increase the local ischaemia and hypoxia associated with chronic venous ulcers. On the other hand, up‐regulation of COX‐2 is most likely responsible for the persistent inflammation in chronic venous leg ulcers. COX‐2 selective inhibitors could therefore be effective in the treatment of chronic venous ulcers. Copyright © 2001 John Wiley & Sons, Ltd.
Effects of the extracellular matrix on lumican expression in rat aortic smooth muscle cells in vitro
Authors: Qin Hanjuan , Ishiwata Toshiyuki , Asano Goro 
Published: August 2002

AbstractLumican is a small leucine‐rich proteoglycan (SLRP), which contributes to cell migration, proliferation, tissue hydration, and collagen fibrillogenesis. Whether lumican is localized in rat aortic smooth muscle cells (SMCs) and what its relationships might be to other extracellular matrix components have not yet been elucidated. In this study, using reverse transcription‐polymerase chain reaction (RT‐PCR), competitive RT‐PCR, and western blot, lumican messenger ribonucleic acid (mRNA) was expressed in cultured rat aortic SMCs. SMCs cultured in serum‐free medium showed four bands at 68, 62, 50, and 37 kD. The 68 and 62 kD bands corresponded to proteoglycan, the 50 kD band to glycoprotein, and the 37 kD band to the core protein form of lumican. The relationships of lumican to fibronectin and laminin were also investigated. The lumican mRNA level in SMCs cultured on fibronectin was highest at day 1, but it increased at day 3 in SMCs cultured on laminin. On the fibronectin or laminin‐coated plates, SMCs expressed only the 68 and 62 kD bands, corresponding to proteoglycan. Pretreatment with anti‐β1 integrin receptor antibody revealed a decrease in the proteoglycan forms of lumican protein and an additional two bands at 50 and 37 kD, indicating glycoprotein and the core protein of lumican. These results show that lumican was synthesized in cultured rat aortic SMCs as proteoglycan, glycoprotein, and core protein. The extracellular matrix (ECM) affected lumican protein production and restricted the lumican protein form to proteoglycan via the β1 integrin receptor in SMCs. Copyright © 2001 John Wiley & Sons, Ltd.
Quantification of the production of dihydrokaempferol by flavanone 3‐hydroxytransferase using capillary electrophoresis
Authors: Owens Daniel K. , Hale Tracy , Wilson Lori J. , McIntosh Cecilia A. 
Published: August 2002

AbstractA sensitive method using capillary electrophoresis for the separation, detection, and quantification of dihydrokaempferol (1) is reported. Well‐resolved, sharp symmetrical peaks were obtained in grapefruit leaf extracts for 1, naringenin (2), and the internal standard, naringin (3). Long columns were required to resolve 1 from 2 in crude enzyme reactions and this resulted in run times of 60 min. The limit of detection for 1 was found to be 1.44 ng/µL (4.2 pg). The method showed excellent linearity and reproducibility. The method was used to determine the activity of flavanone 3‐hydroxytransferase (F3H) in leaf tissue of grapefruit by quantification of the production of dihydrokaempferol in controlled time course reactions. The sensitivity of the method makes it adaptable to assaying F3H activity in individual young seedlings and/or in small tissue samples and requires only 100 mg of tissue. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis of hydrocephalus‐stenosis of the aqueduct of Sylvius by ultrasound in the first trimester of pregnancy. Report of two cases
Authors: Senat M. V. , Bernard J. P. , Delezoide A. , Saugier‐Veber P. , Hillion Y. , Roume J. , Ville Y. 
Published: August 2002

AbstractHydrocephalus‐stenosis of the acqueduct of Sylvius sequence (HSAS) is characterized by hydrocephalus, macrocephaly, adducted thumbs, spasticity, agenesis of the corpus callosum and mental retardation. X‐linked hydrocephalus is known to be due to mutations in the gene coding for the neural cell adhesion molecule L1 (L1‐CAM) and diagnosis is made by identification of a mutation in the L1‐CAM gene. Prenatal diagnosis of HSAS is usually suggested on ultrasound examination showing hydrocephalus in a male fetus associated with bilateral adducted thumbs. Mutation screening of the L1‐CAM gene is indicated when neuropathological examination shows hypoplasia of the corticospinal tract associated with aqueductal stenosis. We report here two cases of HSAS diagnosed within the same family by ultrasound examination in the first trimester of pregnancy when bilateral adducted thumbs were the only early ultrasound marker. Copyright © 2001 John Wiley & Sons, Ltd.
Middle cerebral artery Doppler study in fetuses with homozygous α‐thalassaemia‐1 at 12–13 weeks of gestation
Authors: Hang Lam Yung , Hoi Yin Tang Mary 
Published: August 2002

AbstractObjectiveFetuses affected by homozygous α‐thalassaemia‐1 are anaemic from the first trimester of pregnancy. We investigated middle cerebral artery Doppler velocimetry in these affected fetuses at 12–13 weeks of gestation to assess its use in predicting fetal anaemia.MethodsWomen referred for the prenatal diagnosis of homozygous α‐thalassaemia‐1 before 14 weeks of gestation were recruited. All fetuses underwent pulsed Doppler examinations following colour flow mapping at 12 or 13 weeks of gestation. Homozygous α‐thalassaemia‐1 was diagnosed by DNA or haemoglobin study. The middle cerebral artery Doppler indices were compared between the affected fetuses and fetuses unaffected by homozygous α‐thalassaemia‐1.ResultsBetween 1998 and 2000, 80 eligible women were recruited. Of these, 19 fetuses were affected by homozygous α‐thalassaemia‐1. Two of them showed hydropic changes at the time of Doppler study. The affected fetuses had significantly higher middle cerebral artery peak systolic velocity (Vmax) (36% increase) and time‐averaged maximum velocity (Vtamx) (33% increase).ConclusionThe increase of cerebral blood flow in affected fetuses is consistent with our previous finding of an increased forward flow in the ductus venosus, cardiac dilatation and an increase of cardiac output to preferentially shunt more oxygenated blood to the brain as a compensatory mechanism. However, extensive overlap of the middle cerebral artery flow velocity values between affected and unaffected fetuses precludes its use in predicting anaemia at 12–13 weeks' gestation. Copyright © 2002 John Wiley & Sons, Ltd.
Ultrasound diagnosis of structural abnormalities in the first trimester
Authors: Dugoff Lorraine 
Published: August 2002

AbstractThe advances in ultrasound technology have made it possible to identify fetal structural abnormalities and genetic syndromes in the first trimester. First trimester prenatal diagnosis of fetal central nervous system, renal, gastrointestinal, cardiac, and skeletal abnormalities is reviewed. Copyright © 2002 John Wiley & Sons, Ltd.
The effect of fast reporting by amnio‐PCR on anxiety levels in women with positive biochemical screening for Down syndrome — a randomized controlled trial
Authors: Cheong Leung Wing , Hang Lam Yung , Wong Ying , T. Lau Elizabeth , Hoi Yin Tang Mary 
Published: August 2002

AbstractObjectiveTo study the effect of fast reporting by polymerase chain reaction on amniotic fluid cells (amnio‐PCR) on anxiety levels in women with positive biochemical screening for Down syndrome.MethodBetween May 2000 and April 2001, 60 screen‐positive women were randomized before amniocentesis into either having (group A) or not having (group B) fast‐reporting by amnio‐PCR. Anxiety levels were measured by the Spielberger State‐Trait Anxiety Inventory just prior to amniocentesis, three days (when PCR results were known to group A) and three weeks (when standard karyotype results were known to both groups) afterwards.ResultsTwo women were excluded because in one woman amnio‐PCR showed trisomy 21 and the other miscarried shortly after amniocentesis. The state‐anxiety scores increased over the three‐week period after being informed of the positive‐screen result in both groups. The trait‐ and state‐anxiety scores at all points did not differ between the two groups.ConclusionsIn contrast to the general belief, fast reporting by amnio‐PCR did not alleviate anxiety in women who are screen‐positive for Down syndrome. Copyright © 2002 John Wiley & Sons, Ltd.
Dyslipidaemia and diabetes
Authors: John Betteridge D. 
Published: August 2002

AbstractDyslipidaemia, characterized by hypertriglyceridaemia, low HDL cholesterol, the accumulation of remnant particles and small dense LDL, is one of the major risk factors contributing to the burden of macrovascular disease in type 2 diabetes. It is open to therapeutic intervention by lifestyle and lipid‐lowering drugs and goals for lipid and lipoprotein concentrations are now included in international guidelines for patient management. There is good evidence from subgroup analyses of major coronary heart disease (CHD) secondary prevention trials that lipid‐lowering drugs are beneficial in diabetic patients. Less information is available for primary prevention and the results of on‐going trials performed specifically in diabetic populations are awaited. Nevertheless many patients will fulfil the absolute CHD risk criteria for primary prevention with lipid‐lowering drugs. Copyright © 2001 John Wiley & Sons, Ltd.
Effect of electron‐beam irradiation on poly(vinyl chloride)/epoxidized natural rubber blend: dynamic mechanical analysis
Authors: Ratnam Chantara Thevy , Nasir Mohd , Baharin Azhari , Zaman Khairul 
Published: August 2002

AbstractThe irradiation‐induced crosslinking in 50/50 poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blend was investigated by means of dynamic mechanical analysis. The influence of trimethylolpropane triacrylate on the irradiation‐induced crosslinking of PVC/ENR blends was also studied. The enhancement in storage modulus and Tg with irradiation dose indicated the formation of irradiation‐induced crosslinks. This is further supported by the decrease in tan δmax and loss modulus peak. The compatibility of the blend was found to be improved upon irradiation. The Fox model was used to provide a further insight into the irradiation‐induced compatibility in the blend. Scanning electron microscopy studies on the cryofracture surface morphology of the blends as well as the homopolymer have been undertaken in order to gain more evidence on the irradiation‐induced crosslinking.© 2001 Society of Chemical Industry
Associating behaviour of polyacrylamide modified with a new hydrophobic zwitterionic monomer
Authors: Grassl Bruno , Francois Jeanne , Billon Laurent 
Published: August 2002

AbstractThe nucleophilic ring opening of dicyanoketene ethylene acetal by tertiary amino monomers leads to an hydrophobic zwitterionic monomer [(dimethylammonioethoxy)dicyanoethenolate]propylmethacrylamide (DADPMA) characterized by a very high dipole moment. Hydrophobically modified water soluble polymers have been prepared by classical radical polymerization of acrylamide and DADPMA either in homogeneous medium (water/ethanol mixtures) or in micellar solution (water containing sodium dodecylsulphate (SDS)). The copolymers obtained have a high molecular weight (M
w = 2–5 × 106 g mol−1) and are water soluble for a content of DADPMA lower than 1% mole/mole. The properties of the copolymers in aqueous solution depend on the synthesis conditions, especially on the ratio ethanol:zwitterionic monomer.© 2001 Society of Chemical Industry
Optically active poly(ester‐amide)s: synthesis and characterization
Authors: Philip Biju , Sreekumar K 
Published: August 2002

AbstractThe synthesis and characterization of a new series of chiral poly(ester‐amide)s are reported. They were prepared by the simple reaction of diacid chlorides with biphenolic azo chromophores and optically active dihydroxy compound (isosorbide) in dimethyl acetamide at 100 °C. The polymers containing isosorbide units were optically active. The polymers showed Tg between 100 and 190 °C and were stable up to 400 °C. These poly(ester‐amide)s showed a positive solvatochromism in UV–visible absorption spectra. Second harmonic generation activities were measured by the powder method.© 2001 Society of Chemical Industry
Influence of experimental variables on thermally stimulated recovery results: analysis of simulations and real data on a polymeric system
Authors: Alves N M , Mano J F , Gómez Ribelles J L 
Published: August 2002

AbstractThermally stimulated recovery (TSR) is a low frequency mechanical spectroscopy technique that allows investigation of conformational mobility in polymeric systems. In this study the effect of initial parameters chosen to perform experiments on the TSR response of a material in the thermal sampling mode is investigated. The studied experimental parameters are creep time (tσ) recovery time (tr) and window width (ΔTw); all are independently changed at one constant creep temperature. A simple model, able to describe global TSR and TS measurements, is used to evaluate the influence of each of the different parameters. The simulations are conducted for a system with a uniform distribution of activation energies and a fixed pre‐exponential factor. These simulation results are qualitatively compared with some experimental data obtained for semicrystalline poly(ethylene terephthalate) under different conditions in the glass transition region. The tendencies resulting from the influence of the studied parameters on the intensity, the position of the TS peaks and the corresponding activation energies are found to be the same for the experimental and simulated results. Only the variation of the activation energy with tσ is opposite to that observed with the modelling results; this feature is explained on the basis of structural relaxation effects.© 2002 Society of Chemical Industry
Tensile behaviour of homogeneous ethylene copolymers
Authors: Xu Xu‐Rong , Xu Jun‐Ting , Feng Lin‐Xian 
Published: August 2002

AbstractThe tensile behaviour of homogeneous ethylene–butene copolymer and heterogeneous ethylene–butene copolymer has been compared in uniaxial tension. The homogeneous copolymer exhibits a more marked double yield behaviour. Composition distribution and heat treatment greatly influence the double yield behaviour of ethylene copolymer. A more homogeneous composition distribution has the same effect as rising draw temperature and decreasing draw rate on the double yield behaviour of ethylene copolymers. It is found that the occurrence of the double yield phenomenon is distinguished by the difference between two yield strains. Metallocene‐based ethylene copolymer shows better tensile break properties than conventional ethylene copolymer.© 2002 Society of Chemical Industry
Synthesis and characterization of some polyamides incorporating modified isophthalic acid units
Authors: Onciu Marioara , Rusu Elena 
Published: August 2002

AbstractSome polyamides with side chains were prepared using a direct polycondensation reaction between carboxyl groups from O‐cinnamoyl‐5‐hydroxyisophthalic acid and N‐cinnamoyl‐5‐aminoisophthalic acid and various diisocyanates in the presence of 4‐dimethylaminopyridine, as catalyst, without use of condensing agents. The polymers were characterized by elemental analysis, viscosimetry, spectroscopic and thermal measurements.© 2002 Society of Chemical Industry
Microstructure analysis of N‐vinyl‐2‐pyrrolidone/vinyl acetate copolymers by NMR spectroscopy
Authors: Brar Ajaib S , Kumar Rajeev 
Published: August 2002

AbstractN‐Vinyl‐2‐pyrrolidone (V) and vinyl acetate (A) copolymers of different compositions were synthesized by free radical bulk polymerization. The copolymer composition of these copolymers was determined using quantitative 13C{1H} NMR spectra. The reactivity ratios for these comonomers were determined using the Kelen–Tudos (KT) and non‐linear least‐square error‐in‐variable (EVM) methods. The reactivity ratios calculated from the KT and EVM methods are rV = 2.86 ± 0.16, rA = 0.36 ± 0.09 and rV = 2.56, rA = 0.33, respectively. 1H, 13C{1H} and 1H–13C heteronuclear shift correlation spectroscopy (HSQC) and 1H–1H homonuclear total correlation spectroscopy (TOCSY) were used for the compositional and configurational assignments of V/A copolymers. The 13C distortionless enhancement by polarization transfer (DEPT) technique was used to resolve the methine, methylene and methyl resonance signals in the V/A copolymers.© 2002 Society of Chemical Industry
Effect of isomerization on thermal behaviour of bisitaconimides
Authors: Solanki Anjali , Choudhary Veena , Varma I K 
Published: August 2002

AbstractThe effect of isomerization of N,N′‐bisitaconimido‐4,4′‐diphenyl ether to the corresponding biscitraconimide on the curing characteristics and thermal stability of cured resins is described. Resins having bisitaconimide:biscitraconimide ratios of 23:77–93:7 were prepared by reacting 4,4′‐diaminodiphenyl ether with itaconic anhydride in solvents of different polarities and under different reaction conditions. Resins containing a higher proportion of citraconimide had a lower melting point (191 vs 208 °C). The curing exotherm was observed immediately after melting in all the resins and exothermic peak temperature reduced with increase in citraconimide content. Resins having a higher proportion of citraconimide on isothermal curing (200 °C, 2 h) and subsequent heating in nitrogen atmosphere degraded at a slightly lower temperature. However, the char yield at 800 °C did not show any systematic dependence on citraconimide content.© 2002 Society of Chemical Industry
Gel formation in atom transfer radical polymerization of 2‐(N,N‐dimethylamino)ethyl methacrylate and ethylene glycol dimethacrylate
Authors: Jiang Chengfa , Shen Youqing , Zhu Shiping , Hunkeler David 
Published: August 2002

AbstractCopolymers of 2‐(N,N‐dimethylamino)ethyl methacrylate (DMAEMA) and ethylene glycol dimethacrylate (EGDMA) were synthesized via atom transfer radical polymerization using ethyl 2‐bromoisobutyrate as the initiator, Cu(I)Br as the catalyst, and 1,1,4,7,10,10‐hexamethyltriethylene tetramine as the ligand. At low crosslinker levels, the polymerizations followed the first‐order kinetics. However, when the crosslinker level was above 10 mol %, the ln([M]0/[M]) versus time curves showed deceleration at medium conversions because of the higher reactivity of EGDMA than that of DMAEMA. An acceleration at high conversions was also observed and probably caused by the diffusion limitations of catalyst/ligand complex in the polymer network. The hydrogels were characterized by swelling experiments, and the sol polymers were characterized by the size exclusion chromatographic technique to determine the number‐average molecular weight and polydispersity. The gel data were analyzed and, via a comparison to Flory's gelation theory, found to be more homogeneous than similar hydrogels prepared by conventional free‐radical polymerization methods. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3780–3788, 2001
Amine–quinone polyimides
Authors: Han Mijeong , Nikles David E. 
Published: August 2002

AbstractTwo dianiline monomers were prepared by the reaction of either 4,4′‐methylenedianiline or 4,4′‐oxydianiline with 1,4‐benzoquinone. These monomers were used to synthesize a series of amine–quinone polyimides by condensation with either 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride or 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride to make the corresponding polyamic acid. The polyamic acids were converted to the polyimides by thermal imidization at 290 °C. The amine–quinone polyimides gave freestanding films with tensile strengths in the range of 90 to 150 MPa and Young's moduli of 0.9 to 1.5 GPa. The thermal decomposition temperature under nitrogen was 440 to 480 °C and the glass‐transition temperature was in the range of 280 to 310 °C. The amine–quinone polyimides had the excellent thermal and mechanical properties that one expects for polyimides. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4044–4049, 2001
Synthesis and characterization of novel crosslinkable polymers with a nonlinear optical chromophore as a pendant group
Authors: Jin Sung‐Ho , Kim Sung‐Hyun , Gal Yeong‐Soon 
Published: August 2002

AbstractNew crosslinkable polymers with a nonlinear optical (NLO) active chromophore as a pendant group were synthesized by condensation chain polymerization via palladium‐catalyzed carbon–carbon coupling reactions. The polymerization yields were almost quantitative between the diiodobenzene (DIB) and diethyldipropargyl malonate (DEDPM) or 4‐(dimethylamino)‐4′‐(6‐dipropargylacetoxypropylsulfonyl)stilbene (DASS‐6) monomers. To improve the molecular weight and mechanical properties of the NLO active polymer, we carried out the copolymerization with DIB and DASS‐6 with various feed ratios of DEDPM. The resulting polymers were soluble in organic solvents and spun‐cast onto indium tin oxide‐coated glass substrates to make thin films. The molecular structures of the resulting polymers were characterized with various instrumental methods to confirm the carbon–carbon coupling reactions between the DIB and diacetylene monomers. The absorption of the ultraviolet–visible spectrum of the resulting polymers was drastically reduced after thermal curing at 160 °C because of the crosslinking of the reactive acetylene group in the polymer backbone. The electrooptic coefficient (r33) measured at 1.3 μm ranged from 7 to 15 pm/V. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4025–4034, 2001