bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of HCCl + NOx reactions
Authors: Baren Randall E. , Erickson Mark A. , Hershberger John F. 
Published: August 2002

AbstractThe kinetics of reactions of HCCl with NO and NO2 were investigated over the temperature ranges 298–572 k and 298–476 k, respectively, using laser‐induced fluorescence spectroscopy to measure total rate constants and time‐resolved infrared diode laser absorption spectroscopy to probe reaction products. Both reactions are fast, with k(HCCl + NO) = (2.75 ± 0.2) × 10−11 cm3 molecule−1 s−1 and k(HCCl + NO2) = (1.10 ± 0.2) × 10−10 cm3 molecule−1 s−1 at 296 K. Both rate constants displayed only a slight temperature dependence. Detection of products in the HCCl + NO reaction at 296 K indicates that HCNO + Cl is the major product with a branching ratio of ϕ = 0.68 ± 0.06, and NCO + HCl is a minor channel with ϕ = 0.24 ± 0.04. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 34: 12–17, 2002
Protection against human papillomavirus type 16‐E7 oncogene‐induced tumorigenesis by in vivo expression of dominant‐negative c‐jun†
Authors: Young Matthew R. , Farrell Linda , Lambert Paul , Awasthi Parirokh , Colburn Nancy H. 
Published: August 2002

AbstractExpression of the human papillomavirus (HPV) type 16 E6 and E7 gene products is a risk factor for human cervical carcinogenesis as well as skin and oral carcinogenesis. Expression of the HPV‐16 E7 gene in mouse skin induces hyperplasia and enhances tumor promotion. Expression of dominant‐negative c‐jun (TAM67) in the mouse skin protects mice from 7,12‐dimethylbenz[a]anthracene (DMBA)/12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)–induced papillomagenesis without blocking mitogen‐induced hyperproliferation. To determine the role of activator protein‐1 (AP‐1) in HPV‐induced cancer, we crossed HPV‐16 E7 mice with TAM67 mice and analyzed the effects of DMBA/TPA on tumor promotion. We showed that expression of TAM67 protected mice from HPV‐16 E7–enhanced tumorigenesis, suggesting AP‐1 as a target for prevention of HPV‐induced cancer. Published 2002 Wiley‐Liss, Inc.
Profiling of differentially expressed genes induced by high linear energy transfer radiation in breast epithelial cells
Authors: Roy Debasish , Calaf Gloria , Hei Tom K. 
Published: August 2002

AbstractMethods to define patterns of gene expression have applications in a wide range of biological systems. Several molecular biological techniques are used to study expression patterns during the neoplastic progression of breast epithelial cells. In the present study, differential expression of human oncogenes/tumor suppressor genes in human breast epithelial cell lines irradiated with low doses of high linear energy transfer radiation and treated with estrogen was assessed with cDNA expression arrays. Transformed and tumorigenic cell lines were compared with the control cell line to identify differentially expressed genes during tumorigenic progression. Autoradiographic analysis showed that of the 190 genes analyzed, 49 genes showed a high level of altered expression, and 12 genes had minor differences in expression levels. Among these 49 genes, 17 genes were altered at all stages of transformation, 21 were altered only at the early stage, and the remaining 11 were at the late stage of transformation to the tumorigenic stage of progression. Among the 11 late stage–associated genes, seven genes were altered exclusively in the tumorigenic cell lines and in Tumor‐T. Of the 17 all‐stage genes, six were randomly selected, and we confirmed their altered expression by gene‐specific semiquantitative reverse transcription polymerase chain reaction, followed by Northern blot analysis. The results showed that the mRNA expression patterns of all these genes were consistent with the expression pattern seen on the array. Among these six genes, five genes, including c‐myc, puf, MNDA, c‐yes, and Fra‐1 showed upregulation, and the other gene, RBA/p48, showed downregulation in the transformed and tumorigenic cell lines compared with the control MCF‐10F cell line. Investigation of these genes should help establish the molecular mechanisms of progression that are altered by radiation and estrogen treatment. A number of candidates reported here should be useful as biomarkers involved in breast carcinogenesis. © 2001 Wiley‐Liss, Inc.
Fast optical flip‐flop by use of Mach–Zehnder interferometers
Authors: Hill Martin T. , De Waardt H. , Khoe G. D. , Dorren H. J. S. 
Published: August 2002

AbstractOptical flip‐flops formed from two coupled Mach–Zehnder interferometers are presented. The interferometers employ semiconductor optical amplifiers in their arms. The flip‐flops are demonstrated via simulations and experiments. Low switching energy and very high speed are possible in spite of the relatively slow semiconductor optical amplifier carrier recovery time. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 411–415, 2001.
S‐Parameter broadband measurements of microstrip lines and extraction of the substrate intrinsic properties
Authors: Hinojosa J. , Faucon L. , Queffelec P. , Huret F. 
Published: August 2002

AbstractA measurement technique for the broadband determination of the complex permittivity and permeability of isotropic film‐shaped materials is presented. εr and μr are computed from S‐parameter measurements of microstrip lines propagating in the dominant mode and used as cells. The material under test is the microstrip‐line substrate, which is the original feature of this method in comparison with existing techniques. This leads to a simple and reproducible measurement process. Measurements for several materials in the 0.05–40 GHz frequency range show good agreement between measured and predicted data. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 65–69, 2001.
Oxazine‐ and oxazole‐fused derivatives of the alkaloid boldine and their complete structural and spectral assignments by HMQC and HMBC experiments
Authors: Sobarzo‐Sánchez Eduardo , Cassels Bruce K. , Saitz‐Barría Claudio , Jullian Carolina 
Published: August 2002

AbstractThe novel heterocycles 1,11‐dimethoxy‐2‐hydroxy‐6‐methyloxazolo[4,5‐k]‐5,6,6a,7‐tetrahydro‐4H‐dibenzo [de,g]quinoline, 1,12‐dimethoxy‐2‐hydroxy‐6‐methyl‐9‐phenyl‐10H‐oxazin[5,6‐k]‐5,6,6a,7‐tetrahydro‐4H‐ dibenzo[de,g]quinolin‐10‐one and 1,11‐dimethoxy‐2‐hydroxy‐6‐methyl‐9‐phenyloxazolo[4,5‐k]‐5,6,6a,7‐tetrahydro‐4H‐dibenzo[de,g]quinoline were prepared starting from the alkaloid boldine. The structures were confirmed and the 1H and 13C NMR spectra were completely assigned using a combination of one‐ and two‐dimensional NMR techniques. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of the absolute stereochemistry of vitamin E derived oxa‐spiro compounds by NMR spectroscopy
Authors: Schröder Harald , Netscher Thomas 
Published: August 2002

AbstractThis contribution describes the structure elucidation of dimeric and trimeric oxidation products derived from natural (2R,4′R,8′R)‐α‐ and (2R,4′R,8′R)‐γ‐tocopherol, the most important lipid‐soluble vitamin E compounds and antioxidants in biological systems. Complete 1H and 13C NMR signal assignments have been obtained by combinations of one‐ and two‐dimensional NMR techniques. These structural investigations include full determination of stereochemistry and a study of dynamic processes. Copyright © 2001 John Wiley & Sons, Ltd.
Galactose metabolism in normal human lymphoblasts studied by 1H, 13C and 31P NMR spectroscopy of extracts
Authors: Wehrli, Suzanne L. , Reynolds, Robert , Chen, Jie , Yager Claire , Segal Stanton 
Published: August 2002

AbstractThe development of tools to follow and quantitate the fate of galactose in mammalian cells is crucial to the study and understanding of the inherited disorders of galactose metabolism. In this study we incubated normal human lymphoblasts with 1‐ or 2‐13C galactose for 2.5 or 5 h and prepared TCA extracts of the cells. The various galactose metabolites were identified and quantified using a combination of proton, carbon and phosphorus NMR spectra. Galactose‐1‐phosphate (gal‐1P), uridine diphosphogalactose, uridine diphosphoglucose and galactitol were present in the extracts. Average levels for gal‐1P were around 10 nmol/mg protein and for uridine diphosphoglucose, uridine diphosphogalactose and galactitol in the range of 0.5–2 nmol/mg protein. Galactonate was never found in any conditions. Percentage labeling could be estimated for gal‐1P and for the ribose carbons of AMP. The labeling agrees with a conversion of galactose to glucose through the Leloir pathway. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:

Asp

aspartate

CPD

composite pulse decoupling

gal‐1P

galactose‐1‐phosphate

GALT

galactose 1‐phosphate uridylyl transferase

GB

gaussian factor

Glu

glutamate

LB

line broadening

NOE

nuclear Overhauser effect

PPP

pentose phosphate pathway

TCA

trichloroacetic acid

TSP

trimethylsilylpropionic acid

UDPgal

uridine diphosphogalactose

UDPglu

uridine diphosphoglucose.
Edge‐cutsets in the directed hypercube
Authors: Mariz Paul L. , Shahriari Shahriar 
Published: August 2002

AbstractLet n ≥ 2 and 0 ≤ k ≤ n − 2 be integers. We show that given any collection of k skipless chains in 2[n], the Boolean lattice of order n, there exists n − k edge‐disjoint maximal chains that are edge‐disjoint from the original collection. We also characterize all collections of n − 1 pairwise edge‐disjoint skipless chains in 2[n] with the property that there is no maximal chain that is edge‐disjoint from the collection. Since the Hasse diagram of the Boolean lattice of order n is the n‐dimensional hypercube, the results are applicable to the directed hypercube network. © 2002 Wiley Periodicals, Inc.
A meshless method for Kirchhoff plate bending problems
Authors: Leitão Vitor M. A. 
Published: August 2002

AbstractIn this work a meshless method for the analysis of bending of thin homogeneous plates is presented. This meshless method is based on the use of radial basis functions to build an approximation of the general solution of the partial differential equations governing the Kirchhoff plate bending problem. In order to obtain a symmetric and non‐singular linear equation system the Hermite collocation method is used. To assess the formulation a series of plates with different boundary conditions are analysed. Comparisons are made with other results available in the literature. Copyright © 2001 John Wiley & Sons, Ltd.
Isotopic tracking of prehistoric pinniped foraging and distribution along the central California coast: preliminary results
Authors: Burton R. K. , Gifford‐Gonzalez D. , Snodgrass J. J. , Koch P. L. 
Published: August 2002

AbstractZooarchaeological data from Monterey Bay and the adjacent central California coast corroborate earlier observations from northern California and Oregon that Callorhinus ursinus (northern fur seal) was a much more common component in prehistoric marine mammal prey than its present pelagic distribution and foraging habits would predict. C. ursinus remains from mid‐Holocene Monterey Bay occurrences are predominantly from female individuals, associated with an inshore piscifauna, and lack associated artifactual evidence for deep water exploitation. Taken together with evidence from Oregon, this suggests that mid‐Holocene C. ursinus populations had different foraging, resting, and, arguably, reproductive behaviours than historically reported. Currently debated is whether the contrast between prehistoric and present patterns of pinniped species representation results from: 1) late Holocene prehistoric resource depression by aboriginal hunters, 2) depredations of the early historic fur trade, or 3) non‐anthropogenic climatic or oceanographic change. The issue has thus far been addressed with presence or absence data on pinniped species and age/sex classes in dated contexts. While these are fundamental data, they cannot shed light on the nature of foraging behaviour of the species in question, a key dimension of the problem. This paper reports a pilot study utilizing stable isotope analysis aimed to elucidate prehistoric pinniped foraging patterns, specifically that of C. ursinus. Elements from six archaeological sites in Monterey and Santa Cruz counties were analysed for stable isotope compositions of carbon and nitrogen in bone collagen and compared to a latitudinally ordered modern dataset. Results for archaeological C. ursinus strongly suggest that prehistoric animals habitually foraged at lower latitudes than characterize the species today, supporting earlier claims of their year‐round residency south of Alaska. Copyright © 2002 John Wiley & Sons, Ltd.
Hydrophobically modified polyelectrolytes II: synthesis and characterization of poly(acrylic acid‐co‐alkyl acrylate)
Authors: Zhuang Dong‐qing , Ai‐hua Da Jie Chen , Zhang Yun‐xiang , Dieing Reinhold , Ma Lian , Haeussling Lukas 
Published: August 2002

AbstractA series of hydrophobically modified poly(acrylic acid)(R
H‐PAA) were synthesized by solution copolymerization of acrylic acid with a small amount of alkyl acrylate (alkyl chain with a length of 8, 12, 14, 16, 18) and their solution properties were also systematically studied. It was found that the random distribution of alkyl acrylate along the polymeric backbone imparts these new materials pronounced associating ability in aqueous solution and the associating abilities vary with the chain length of the hydrophobic groups. In dilute solution, intramolecular association is observed from the intrinsic viscosity and the dependence of the intrinsic viscosity on chain length and ionic strength is also discussed. In semiconcentration solution, the modified polymers exhibit viscosities of several orders of magnitude higher than the unmodified poly(sodium acrylate) due to the strong intermolecular hydrophobic association. And the viscosifying effects become more significant with the increasing length of the alkyl chain. The copolymer solutions are highly pseudoplastic. Evidences for the hydrophobically associating interaction between hydrocarbon groups are provided by the dependence of the Brookfield viscosity on concentration, temperature, shear rate, ionic strength and pH. Copyright © 2001 John Wiley & Sons, Ltd.
Preparation of silica‐supported methylcellulose‐L‐proline–Pt complex and its catalytic behaviors in asymmetric hydrogenation of propiophenone
Authors: Huang Kai , Xue Lei , Huang Mei‐Yu , Jiang Ying‐Yan 
Published: August 2002

AbstractA new chiral polymer–metal complex, silica‐supported methylcellulose‐L‐proline–Pt complex (SiO2‐MC‐LP–Pt) has been found to be a high optically active catalyst for asymmetric hydrogenation of propiophenone to (R)‐1‐phenyl‐1‐propanol at 30 °C and under atmospheric hydrogen pressure. The product and optical yields of 1–phenyl‐1‐propanol amounted to 62.5 and 92.2%, respectively. The product and optical yields were remarkably affected by the Pt content in the complex, the kind of solvent and the reaction temperature. This catalyst was very stable and could be reused several times without remarkable change in optical catalytic activity. Copyright © 2001 John Wiley & Sons, Ltd.
Trends in primary care antibiotic prescribing in England 1994–1998
Authors: Unsworth L. , Walley T. 
Published: August 2002

AbstractPurposeTo investigate the changing decisions to prescribe antibiotics as manifest in the patterns of prescriptions dispensed in England, and to investigate antibiotic prescribing in different types of practice.MethodsAntibiotic prescribing data and practice characteristics collected for every practice in England for the years 1994/5–1997/8. Morbidity data for common infections was also obtained from published sources.ResultsAntibiotic prescribing was related to practice characteristics, with high prescribing in deprived and single‐handed practices in particular. There was a fall in antibiotic prescribing in all types of practice of practice over the period of the study. Morbidity data from other sources shows a fall in diagnosed morbidity from some infectious diseases over the same period. There were no differences in choice of antibiotic in different types of practice.ConclusionsThe fall in antibiotic prescribing is universal across all kinds of practices and is possibly related to the fall in diagnoses. It is uncertain whether this reflects true morbidity. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of the silica content on rheological behaviour and cure characteristics of silica‐filled styrene–butadiene rubber compounds
Authors: Choi Sung‐Seen 
Published: August 2002

AbstractRheological behaviour and cure characteristics of silica‐filled styrene–butadiene rubber (SBR) compounds and SBR compounds filled with both silica and carbon black with different silica contents were investigated. Rheocurves of the time versus the torque of the compounds showed specific trends with the silica content. For the compounds with low silica content (less than 50 phr), the torque decreased immediately after the steep increase at the initial point of the rheocurve and then increased very slowly. For the compounds with high silica content (more than 50 phr), the rheographs showed two minimum torque points; the torque decreased immediately after the steep increase at the start point of the rheocurve and then increased sharply before reaching the second minimum point. This can be explained by the strong filler–filler interaction of silica. The minimum torque of the compound increased slightly with an increase of the silica content up to 50 phr silica content and then increased appreciably. For the silica‐filled compounds, cure times of the t02, t40, and t90 became shorter with an increase of the filler content. For the compounds filled with both silica and carbon black (total filler content of 80 phr), the cure times became longer with an increase of the silica content ratio.© 2001 Society of Chemical Industry
Reactive processing of acrylic–polyurea interpenetrating networks: reaction kinetic studies
Authors: Stanford John L , Ryan Anthony J , Yang Ying 
Published: August 2002

AbstractInterpenetrating networks (IPNs), comprising a crosslinked acrylic polymer as one component and either a polyurea, a segmented copolyurea or a copoly(urea–isocyanurate) as the other component, have been formed by reaction injection moulding (RIM). The effects on the processability and the formation of the IPNs of (i) the crosslinker concentration in the acrylic component, (ii) the functionality of the amine‐functionalized polyether used for the polyurea, and (iii) the weight fractions of acrylic components are evaluated. Reaction kinetics during RIM processing of the IPNs are studied using adiabatic temperature rise (ATR) measurements. The macroscopic structures of RIM materials, determined via optical microscopy, are used to assess the mixing characteristics operative during reactive processing of the various IPNs. The results are interpreted in terms of differences in the rates of polymerization and in the solubilities of the acrylic‐ and polyurea‐forming components.© 2001 Society of Chemical Industry
Synthesis and characterization of a novel functional monomer containing cyano and propenylphenoxy groups and the properties of its copolymer with bismaleimide (BMI)
Authors: Fang Qiang , Yu Yi‐Hua , Huang Hao , Chao Qi‐Rong , Jiang Lu‐Xia 
Published: August 2002

AbstractA novel functional monomer containing cyano and propenylphenoxy groups, 2,6‐di{2‐[(E)‐l‐propenyl]phenoxy}benzonitrile (DPPB) was prepared with high stereospecificity by the reaction of 2,6‐dichlorobenzonitrile and 2‐allylphenol in a mixed solvent system of N‐methylpyrrolidone (NMP)/toluene in the presence of anhydrous potassium carbonate. The chemical structure of the product was characterized by FTIR, 1H NMR and 13C NMR. The monomer was then used to modify a popular commercial bismaleimide, 4,4‐bismaleimidodiphenylmethane (BMDPM), for improving the shear strength of the resin. The results showed that the modified resin could attain 4.7 times the shear strength of neat BMDPM and good heat resistance when the composition of DPPB in the modified resin was 45% (by weight).© 2002 Society of Chemical Industry
Synthesis, NMR characterization and pharmacological evaluation of ligands derived from diprenorphine for central opioid receptors imaging
Authors: Bourrel François , Massou Stéphane , Baltas Michel , Bergon Michel , Tafani Mathieu , Esquere Jean‐Paul , Tisnès Pierre , Prigent Yann 
Published: August 2002

AbstractThe aim of this work was to explore the synthesis of a tosylated derivative of diprenorphine (DPN) able to be radiolabeled with either fluorine‐18 or iodine‐123, making it suitable for PET or SPECT imaging studies of central opioid receptors, respectively. The strategy was based on the reactivity of the C‐19 alcohol tertiary function. As an unexpected deacetylation of the phenolic function of the diprenorphine occurred, the prosthetic group reacted with the deprotected C‐3 phenolic function instead of the C‐19 alcohol group. UV spectroscopy and 1H and 13C NMR studies provided good evidence for the 3‐phenolic substituted diprenorphine structure. Thorough 2D NMR experiments such as 1H–1H COSY, 1H–1H TOCSY, 1H–13C HMQC, 1H–13C HMBC and 1H–1H NOESY allowed us to assign fully 3‐O‐[(Z)‐4‐fluorobut‐2‐enyl] diprenorphine (10a) and gave us an unambiguous proof of the C‐3 prosthetic group position. In vitro binding studies showed low affinity for both fluoro and iodo derivatives of diprenorphine, Ki = 0.31 ± 0.05 and 0.09 ± 0.03 µM, respectively, for mouse brain membranes, these inhibition constants also being in agreement with a 3‐phenolic substituted structure. Copyright © 2001 John Wiley & Sons, Ltd.
Dual‐parameter correlations on rate of dehydration step of a condensation reaction in aqueous solutions of ethanol, propan‐2‐ol and 2‐methylpropan‐2‐ol
Authors: Yangjeh A. Habibi , Gholami M. R. , Mostaghim R. 
Published: August 2002

AbstractThe reaction kinetics of the dehydration step of the condensation reaction between phenylhydrazine and benzaldehyde was studied spectrophotometrically in aqueous solutions of ethanol, propan‐2‐ol and 2‐methylpropan‐2‐ol at pH 11.5 at 25 °C. The apparent second‐order rate constants k2app of the reaction increase with mole fraction of water in all the aqueous solutions. Single‐parameter correlations of log k2app versus π* (dipolarity/polarizability), α (hydrogen‐bond donor acidity) and $E_{\rm T}^{\rm N}$ (normalized polarity parameter) were obtained in all the aqueous solutions. In all cases, the correlations versus $E_{\rm T}^{\rm N}$ and π* are acceptable, but correlations versus α are poor (e.g. in aqueous solutions of ethanol the correlation coefficients are 0.964, 0.967, and 0.751 respectively). The results of dual‐parameter correlations of log k2app versus π* and α in all cases represent improvements with regard to the single‐parameter models (in aqueous solutions of ethanol r = 0.995; s.e. = 0.038; n = 13). The apparent second‐order rate constants of the reaction increase with α, π* and $E_{\rm T}^{\rm N}$. Increasing the hydrogen‐bond donor acidity of the solvent stabilizes the activated complex of the reaction via hydrogen‐bond formation with the intermediate. A dual‐parameter equation of log k2app versus π* and α was obtained for the combined data set of aqueous solutions (n = 35, r = 0.989, s.e. = 0.062, F2,32 = 719.21), in which π* has the major effect on the reaction rate relative to α. Copyright © 2001 John Wiley & Sons, Ltd.