bluuebunny/crossref_metadata_2025 huggingface dataset:
Adipokines in NASH: Postprandial Lipid Metabolism as a Link Between Adiponectin and Liver Disease *
Authors: Musso Giovanni , Gambino Roberto , Durazzo Marilena , Biroli Giampaolo , Carello Monica , Fagà Emanuela , Pacini Giovanni , De Michieli Franco , Rabbione Laura , Premoli Alberto , Cassader Maurizio , Pagano Gianfranco
Published: October 2005

Abstract

Circulating levels of four adipokines (adiponectin, TNF-α, leptin, and resistin) and the postprandial lipid and adiponectin responses to an oral fat load were assessed in 25 non-obese, non-diabetic patients with biopsy-proven nonalcoholic steatohepatitis (NASH) and correlated with metabolic indices and liver histology. Circulating adiponectin was lower in NASH compared with controls (5,476 ± 344 vs. 11,548 ± 836 ng/mL;

P

= .00001) and on multiple regression analysis correlated negatively with liver steatosis, necroinflammation (OR = 5.0;

P

= .009), and fibrosis (OR = 8.0;

P

= .003).The magnitude of postprandial lipemia was significantly higher in NASH than in controls and was related to fasting adiponectin (β = −0.78;

P

= .00003). Controls showed a significant increase in serum adiponectin in response to the fat load, whereas patients with NASH showed a slight decrease. Postprandial free fatty acids response correlated inversely with adiponectin response in both groups and independently predicted the severity of liver steatosis in NASH (β = 0.51;

P

= .031).
In conclusion
, hypoadiponectinemia is present before overt diabetes and obesity appear and correlates with the severity of liver histology in NASH. Impaired postprandial lipid metabolism may be an additional mechanism linking hypoadiponectinemia and NASH and posing a higher cardiovascular risk to these subjects. The mechanism(s) underlying these differences are unknown, but the type of dietary fat seems to play a role. These findings may have important pathogenetic and therapeutic implications in both liver and metabolic disease. (Hepatology 2005.)
Dietary and lifestyle determinants of mammographic breast density. A longitudinal study in a Mediterranean population
Authors: Masala Giovanna , Ambrogetti Daniela , Assedi Melania , Giorgi Daniela , Del Turco Marco Rosselli , Palli Domenico
Published: October 2005

High mammographic breast density (H‐MBD) has been associated with increased breast cancer (BC) risk, even after adjustment for established BC risk factors. Only a few studies have examined the influence of diet on MBD. In a longitudinal study in Florence, Italy, we identified about 2,000 women with a mammogram taken 5 years after enrollment, when detailed information on dietary and lifestyle habits and anthropometric measurements had been collected. Original mammograms have been identified and retrieved (1,668; 83%), and MBD was assessed by 2 experienced readers, according to Wolfe's classification and a semiquantitative scale. By logistic analysis, we compared women with H‐MBD (P2 + DY according to Wolfe's classification) with those with low‐MBD (N1 + P1). H‐MBD was confirmed to be inversely associated with BMI, number of children and breast feeding, while it was directly associated with higher educational level, premenopausal status and a previous breast biopsy. In multivariate analyses adjusted for nondietary variables, H‐MBD was inversely associated with increasing consumption of vegetables (p for trend = 0.005) and olive oil (p for trend = 0.04). An inverse association was also evident between H‐MBD and frequent consumption of cheese and high intakes of β‐carotene, vitamin C, calcium and potassium (p for trend ≤ 0.05). On the other hand, we found a positive association with increasing consumption of wine (p for trend = 0.01). This large longitudinal study, the first carried out in Mediterranean women, suggests that specific dietary components may play a key role in determining MBD in this population, thus possibly modulating BC risk. © 2005 Wiley‐Liss, Inc.
FHIT protein enhances paclitaxel‐induced apoptosis in lung cancer cells
Authors: Kim Cheol Hyeon , Yoo Jung Sun , Lee Choon‐Taek , Kim Young Whan , Han Sung Koo , Shim Young‐Soo , Yoo Chul‐Gyu
Published: October 2005

The fragile histidine triad (FHIT) gene is a frequent target of deletions in lung cancer. Previous studies have shown that FHIT gene transfer into lung cancer cells lacking FHIT expression results in induction of apoptosis. However, the effect of FHIT expression on apoptosis induced by chemotherapeutic agents and its intracellular mechanism is poorly understood. This study was undertaken to elucidate the effect of FHIT expression and the role of Bcl‐2‐caspase signaling in paclitaxel‐induced apoptosis in lung cancer cells. NCI‐H358 lung cancer cells, which lack FHIT expression, were stably transfected with plasmid vector containing FLAG‐tagged wildtype FHIT. We investigated effects of paclitaxel on apoptosis, activation of caspase system and expression of Bcl‐2 family. We next evaluated whether these effects were reversed by blocking FHIT expression using siRNA. Paclitaxel enhanced apoptosis in FHIT‐expressing cells compared to that in control vector‐transfected cells, and this enhancement was suppressed by siRNA treatment. Activities of caspase‐3 and caspase‐7, but not of caspase‐8, were higher in FHIT‐expressing cells than in control vector‐transfected cells, and this was reduced by siRNA treatment. When caspase activation was blocked by a pan‐caspase inhibitor in FHIT‐expressing cells, paclitaxel‐induced apoptotic cell death was decreased similar to that in control vector‐transfected cells. Bcl‐2 and Bcl‐xL expressions were down‐regulated after paclitaxel treatment in FHIT‐expressing cells, whereas Bax and Bad expressions were up‐regulated. These were reversed by siRNA treatment. These results indicate that paclitaxel‐induced apoptosis enhanced by FHIT expression in lung cancer cells might be associated with modulation of Bcl‐2‐caspase signaling. © 2005 Wiley‐Liss, Inc.
Daily timed meals dissociate circadian rhythms in hepatoma and healthy host liver
Authors: Davidson Alec J. , Straume Martin , Block Gene D. , Menaker Michael
Published: October 2005

Dividing cells, including human cancers, organize processes necessary for their duplication according to circadian time. Recent evidence has shown that disruption of central regulation of circadian rhythms can increase the rate at which a variety of cancers develop in rodents. To study circadian rhythms in liver tumors, we have chemically induced hepatocellular carcinoma in transgenic rats bearing a luciferase reporter gene attached to the promoter of a core circadian clock gene (Period 1). We explanted normal liver cells and hepatomas, placed them into short‐term culture, and precisely measured their molecular clock function by recording light output. Results show that isolated hepatocellular carcinoma is capable of generating circadian rhythms in vitro. Temporally restricting food availability to either day or night altered the phase of the rhythms in both healthy and malignant tissue. However, the hepatomas were much less sensitive to this signal resulting in markedly different phase relationships between host and tumor tissue as a function of mealtime. These data support the conclusion that hepatoma is differentially sensitive to circadian timing signals, although it maintains the circadian organization of the nonmalignant cells from which it arose. Because circadian clocks are known to modulate the sensitivity of many therapeutic cytotoxic targets, controlling mealtiming might be used to increase the efficacy of treatment. Specifically, meal and treatment schedules could be designed that take advantage of coincident times of greatest tumor sensitivity and lowest sensitivity of host tissue to damage. © 2005 Wiley‐Liss, Inc.
MALDI‐TOF MS characterization of proanthocyanidins from cranberry fruit (Vaccinium macrocarpon) that inhibit tumor cell growth and matrix metalloproteinase expression in vitro
Authors: Neto Catherine C , Krueger Christian G , Lamoureaux Toni L , Kondo Miwako , Vaisberg Abraham J , Hurta Robert AR , Curtis Shannon , Matchett Michael D , Yeung Horace , Sweeney Marva I , Reed Jess D
Published: October 2005

Proanthocyanidin‐rich extracts were prepared by fractionation of the fruit of the North American cranberry (Vaccinium macrocarpon). In vitro growth inhibition assays in eight tumor cell lines showed that selected fractions inhibited the growth of H460 lung tumors, HT‐29 colon and K562 leukemia cells at GI50 values ranging from 20 to 80 µg ml−1. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) of one of these fractions found it to be composed of polyflavan‐3‐ols, which are primarily tetramers through heptamers of epicatechin containing one or two A‐type linkages. Whole cranberry extract and the proanthocyanidin fractions were screened for effect on the expression of matrix metalloproteinases in DU 145 prostate carcinoma cells. The expression of MMP‐2 and MMP‐9 was inhibited in response to whole cranberry extract and to a lesser degree by the proanthocyanidin fractions. Copyright © 2005 Society of Chemical Industry
Rod‐Length Dependent Aggregation in a Series of Oligo(p‐benzamide)‐Block‐Poly(ethylene glycol) Rod‐Coil Copolymers
Authors: Abbel Robert , Schleuss Tobias W. , Frey Holger , Kilbinger Andreas F. M.
Published: October 2005

Summary:The synthesis of a series of rod‐coil diblock copolymers with flexible poly(ethylene oxide) chains ($\overline M _{\rm n}$ = 5 000 g · mol−1) and rod blocks consisting of monodisperse oligo(p‐benzamide)s is described. The formation of defined supramolecular aggregates in solution as well as the solid state has been analyzed. The length of the oligo(p‐benzamide)s has been systematically varied fromn = 1 to 7 units. The influence ofnon aggregation in chloroform and aqueous solution was investigated by GPC as well as UV‐vis spectroscopy. A critical aggregation length was found for chloroform (n = 5) and water (n = 4), below which no aggregation is observed under otherwise identical experimental conditions. Aggregation of the polymers in chloroform solution can be chemically reversed by the addition of PCl5, resulting in conversion of the aromatic amides into imidoyl chlorides. Such amide‐protected block copolymers show no aggregation in NMR and GPC experiments. Imidoyl chloride formation was shown to be reversible, i.e., addition of water regenerated the oligo(p‐benzamide) blocks.

Conversion of aramide block copolymer into molecularly dissolved form using PCl5.

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Conversion of aramide block copolymer into molecularly dissolved form using PCl5.
Epoxy Resin Containing Octamaleimidophenyl Polyhedral Oligomeric Silsesquioxane
Authors: Ni Yong , Zheng Sixun
Published: October 2005

Summary: Octamaleimidophenyl polyhedral oligomeric silsesquioxane (OmipPOSS) was synthesized via the imidization reaction between octaaminophenyl polyhedral oligomeric silsesquioxane (OapPOSS) and maleic anhydride, and it was characterized by means of Fourier transform infrared (FTIR) and NMR spectroscopies. OmipPOSS was further employed to prepare epoxy hybrids. The thermosetting hybrids containing OmipPOSS up to 10 wt.‐% were obtained via in situ polymerization of diglycidyl ether of bisphenol A (DGEBA) and 4,4′‐diaminodiphenylmethane (DDM) in the presence of OmipPOSS. High‐resolution transmission electronic microscopy (TEM) indicates that the nanometer‐scaled dispersion of POSS molecules was obtained, suggesting that the nanocomposites were successfully prepared. The results of DSC showed that the glass transition temperatures (Tg's) of the POSS‐containing nanocomposites are dependent on the content of POSS in the nanocomposites. When the contents of POSS are less than 5 wt.‐%, the nanocomposites displayed the enhanced glass transition temperatures (Tg's) in comparison with control epoxy. Thermogravimetric analysis (TGA) showed that all the nanocomposites containing POSS displayed improved char yield, suggesting the flame retardance of the materials is improved.

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Efficient Synthesis and Copolymerization of Poly(acrylic acid) and Poly(acrylic ester) Macromonomers: Manipulation of Steric Factors
Authors: McHale Ronan , Aldabbagh Fawaz , Carroll William M. , Yamada Bunichiro
Published: October 2005

Summary: Macromonomers have been prepared by polymerization of acrylic acid (AA) and tert‐butyl acrylate (tBA) in the presence of the addition‐fragmentation chain transfer (AFCT) agents, ethyl α‐(bromomethyl)acrylate (EBMA) and tert‐butyl α‐(bromomethyl)acrylate (BBMA). Chain transfer constants of 1.25 (EBMA) and 1.14 (BBMA) in the AA polymerization, and 2.42 (EBMA) and 1.75 (BBMA) in the tBA polymerization were obtained. The reduction in molecular weight with increasing concentration of AFCT agent and efficient introduction of 2‐carbalkoxy‐2‐propenyl ω‐end group was indicative of macromonomer formation. Polymerizations were retarded with increasing concentrations of AFCT agent and increases in the absolute concentration of EBMA slowed down the polymerization of AA but not tBA. The difference between EBMA and BBMA was less significant with tBA; more efficient macromonomer synthesis was indicated by less retardation and greater double bond retention at higher conversions. Copolymerizations of poly(AA) and poly(tBA) macromonomers with styrene indicated that the former was more reactive towards the St propagating radical. The results are rationalized in terms of the steric hindrance imposed by the tert‐butyl group. Poly(tBA) macromonomer was successfully hydrolyzed to give an alternative route to the poly(AA) macromonomer.

Reaction mechanism for macromonomer synthesis using AFCT.

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Reaction mechanism for macromonomer synthesis using AFCT.
Controlling the Thermosensitive Gelation Properties of Poly(organophosphazenes) by Blending
Authors: Kang Gyung Don , Heo Jeong‐Yun , Jung Sung Bum , Song Soo‐Chang
Published: October 2005

Summary: After synthesizing both hard poly(organophosphazenes), which acted as strong hydrogels at a temperature below 37 °C, and soft poly(organophosphazenes), which displayed the opposite properties, we blended the polymers. When these polymers were blended at an appropriate ratio, the blended aqueous solution changed into a transparent hydrogel with improved mechanical properties at a temperature of 37 °C. According to DSC and IR measurements, the two polymers blended homogeneously and exhibited a behavior characteristic of a completely different copolymer.

An aqueous poly(organophosphazene) solution at room temperature (left) is reversibly and rapidly transformed into a transparent hydrogel at body temperature (right) when a hard poly(organophosphazene) is blended with a soft one at an appropriate ratio.

image

An aqueous poly(organophosphazene) solution at room temperature (left) is reversibly and rapidly transformed into a transparent hydrogel at body temperature (right) when a hard poly(organophosphazene) is blended with a soft one at an appropriate ratio.
Front Cover: Macromol. Rapid Commun. 20/2005
Authors: Yu Haifeng , Shishido Atsushi , Ikeda Tomiki , Iyoda Tomokazu
Published: October 2005

Front Cover: Novel amphiphilic diblock and triblock LC copolymers with well‐defined structures were prepared by ATRP. The low content AZO in the triblock copolymer can be used as a photo‐trigger to regulate the non‐AZO mesogens and change the PEO domains formed in microphase separation. Further details can be found in the Communication by H. Yu, A. Shishido, T. Ikeda,* and T. Iyoda on page 1594.
Modeling and Sensitivity Analysis of Particle Size Distribution and Chain Length Distribution in a Semibatch Emulsion Copolymerization Reactor
Authors: Park Myung‐June , Dokucu Mustafa T. , Doyle Francis J.
Published: October 2005

Summary: A comprehensive model is developed to predict the relationship between the particle size distribution and molecular weights of particles in an emulsion copolymerization reactor. A full population balance equation is used for the particle size distribution and extended to the model for the molecular properties using a continuous reactor approach. The numerical prediction clearly distinguishes the characteristics of molecular properties of particles by homogeneous nucleation from those by micellar nucleation with the dependence on the particle size. Sensitivity analysis of the proposed model under a variety of conditions shows that the compartmentalized feature of the emulsion system should be considered for better prediction of molecular properties, and provides information on the manipulated variables and lumped parameters which effectively decompose the correlation of both properties. Finally, a control strategy utilizing a lumped parameters tracking method is suggested for the regulation of both the particle size distribution and molecular properties.

Time evolution of number‐averaged molecular weights in the element under base conditions.

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Time evolution of number‐averaged molecular weights in the element under base conditions.
The Effect of Chain Architecture on the Dynamics of Copolymers in a Homopolymer Matrix: Lattice Monte Carlo Simulations using the Bond‐Fluctuation Model
Authors: Kamath Sudesh Y. , Dadmun Mark D.
Published: October 2005

Summary: The effects of copolymer sequence distribution on the dynamics of a copolymer in a homopolymer matrix are studied using computer simulations within the framework of the bond‐fluctuation model on blends containing low concentrations (10%) of copolymers dispersed in a homopolymer matrix. The sequence distribution of the two copolymer components was changed while maintaining the overall copolymer composition at 50/50. Our results indicate that copolymers with disordered sequence distributions exhibit dynamics that are faster than that of a homopolymer melt, while those with ordered sequence distributions exhibit a tendency to form aggregates that lead to slower dynamics as well as phase separation. Analysis of the structure suggests that copolymers with an alternating sequence distribution form large aggregates that are short‐lived, while diblocks form permanent micelle‐like structures. Analysis of the local composition around a copolymer molecule indicates that aggregation between copolymer chains has a direct impact on the local composition. This in turn has a significant impact on system dynamics. Our results indicate that the dynamics of random, random‐blocky, and alternating copolymers are nearly identical and are faster than that of a homopolymer melt. However, alternating copolymers form aggregates and hence are not uniformly distributed throughout the matrix phase. Thus, alternating copolymers are at a disadvantage in their ability to be effective compatibilizers. From a dynamic perspective, copolymers with random and random‐blocky copolymers seem to be ideal compatibilizers since they are distributed uniformly throughout the system and move rapidly through the matrix phase.

Snapshots of aggregates of alternating copolymer chains. Dark and bright spheres represent A and B monomers, respectively.

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Snapshots of aggregates of alternating copolymer chains. Dark and bright spheres represent A and B monomers, respectively.
Cover Picture: Macromol. Theory Simul. 8/2005
Authors: Nie Zhihong , Su Zhaohui , Sun Zhaoyan , Shi Tongfei , An Lijia
Published: October 2005

Cover: The picture schematically describes the definition of the axes and how to clearly understand the orientation and shape of polymer chains for this system. If the system is in a disordered state or in the ODT process, the axes are defined as if the system were in the ordered state. Thus we can clearly monitor the change of the polymer conformation with temperature and film thickness. Further details can be found in the Full Paper by Z. Nie, Z. Su, Z. Sun, T. Shi,* and L. An* on page 463.
Medieval big cat remains from the Royal Menagerie at the Tower of London
Authors: O'Regan H. , Turner A. , Sabin R.
Published: October 2005

Big cats have been regarded as a symbol of power in different cultures throughout history. Here we present a study of the only known big cat remains from the Royal Menagerie at the Tower of London. They were excavated in 1937 but have not previously been published. Our radiocarbon dating has established that they range in date from the 13th–17th centuries, making them the earliest post‐Pleistocene big cat remains in Britain. We provide a description of the specimens–two lion skulls, a fragmentary leopard, plus 19 dog crania–and discuss the partially occluded foramen magnum of one of the lions. This anomaly has also been noted in captive and unprovenanced cat skulls from the early 20th century, indicating that it is a condition with a long history. We discuss the remains, the history of the menagerie, and the uses of the animals, in the light of our knowledge of conditions for captive animals at the time. Zooarchaeological studies such as these may also provide insights for modern conservation of zoo animals, and this aspect of the work is also considered. Copyright © 2005 John Wiley & Sons, Ltd.
Limitations with the response evaluation criteria in solid tumors (RECIST) guidance in disseminated pediatric malignancy
Authors: Barnacle A.M. , McHugh Kieran
Published: October 2005

Background

Response evaluation criteria in solid tumors (RECIST) guidelines were published in 2000 to evaluate response to treatment in solid tumors. These have sought to unify response assessment, and the new guidelines extend beyond lesion assessment to address modern imaging strategies. The RECIST guidelines, however, become complex and problematic when used to evaluate metastatic disease.

Methods

Ten consecutive oncology cases representative of tumors common to our pediatric practice were selected. All cases were evaluated at initial presentation and follow‐up. The RECIST criteria were retrospectively applied in each case. A standardized evaluation form was used.

Results

The age range of the patients included in the study was 1 month to 16 years, with a mean age of 3.9 years. A range of tumor responses was identified: partial response (n = 6), stable disease (n = 2), and progressive disease (n = 2). Two of these responses were likely incorrect. Tumor bulk was underestimated in the axial plane, many lesions were either calcified and unmeasurable, or despite being well‐defined were too small to be measurable under the strict RECIST guidance.

Conclusion

In highlighting specific problems with disseminated pediatric tumors, we emphasize the pressing need for debate regarding the application of RECIST in pediatric oncology and encourage the development of a pediatric radiology oncology group to collaborate in future modifications of the RECIST guidance. Pediatr Blood Cancer. © 2005 Wiley‐Liss, Inc.
Mn(III) oxidation of peptide polymers of elastin sequences: synthesis, kinetics and mechanistic study
Authors: Abiraj K. , Baba A. Ramesha , Srinivasa G. R. , Gowda D. Channe
Published: October 2005

Protein based‐polymers comprised of Ala‐, Val‐ and Ile‐containing tetrapeptide repeating sequences of elastin were synthesized based on the increasing order of hydrophobicity and subjected to metal‐catalyzed oxidation to identify the amino acid residues, which are sensitive to oxidation. These polytetrapeptides (PTP) were oxidized using Mn(OAc)3 at 25°C and the kinetics of the reaction were monitored spectrophotometrically at λmax = 400 nm. A first‐order rate dependence on the substrate concentration [PTP] and [Mn(III)] and an inverse order dependence on [H+] has been observed. Further, the rate is independent of [Mn(OAc)2]. The effect of the dielectric constant on the rate was studied by varying the percentage of AcOH. Activation parameters were evaluated using Arrhenius and Eyring plots. The oxidation products were isolated and characterized. Based on the results obtained, a plausible mechanism involving [Mn(OAc)4]− is proposed. It is noteworthy that the rate of oxidation of poly(GGIP) was higher than those of poly(GGVP) and poly(GGAP). This may be due to their increased hydrophobicity. The overall order of rate of oxidation of PTP is poly(GGIP) > poly(GGVP) > poly(GGAP). Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and metathesis activity of ruthenium dimethylvinyl carbene complexes
Authors: Lehman Stephen E. , Wagener Kenneth B. , Akvan Shahab
Published: October 2005

Two new dimethylvinyl carbene complexes, RuCl2(SIMes)(PPh3)CHCHC(CH3)2 and RuCl2(SIMes)(3BP)2CHCHC(CH3)2, were synthesized from RuCl2(PCp3)2CHCHC(CH3)2. Complex RuCl2(SIMes)(3BP)2CHCHC(CH3)2 does not suffer from the problem of incomplete initiation that has been observed for the other dimethylvinyl carbene complexes, as witnessed by complete and rapid reaction with ethyl vinyl ether. Acyclic diene metathesis (ADMET) polymerization of 1,9‐decadiene with these complexes was found to give polymers with chemical and thermal properties similar to those obtained with Schrock's molybdenum catalyst. These complexes are also catalysts for ring‐opening metathesis polymerization. The parent complex RuCl2(SIMes)(PCp3)CHCHC(CH3)2 was found to give polyoctenamer with high initial heats of fusion, suggesting a dependence of the “as formed” crystallinity of the polymer on the rate of the ROMP reaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6134–6145, 2005
Preparation, characterization, and thermal properties of alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,3‐bis(ethylene)permethyloligosiloxanylene]s
Authors: Lee Nam S. , Gädda Thomas M. , Weber William P.
Published: October 2005

alt‐Copoly[1,9‐decaphenylpentasiloxanylene/1,3‐bis(ethylene)tetramethyldisiloxanylene], alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,5‐bis(ethylene)hexamethyltrisiloxanylene], alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,7‐bis(ethylene)octamethyltetrasiloxanylene], and alt‐copoly[1,9‐decaphenylpentasiloxanylene/1,9‐bis(ethylene)decamethylpentasiloxanylene] were synthesized by Pt‐catalyzed hydrosilylation reactions of 1,9 divinyldecaphenylpentasiloxanes with a series of oligodimethylsiloxanes. The molecular weights of these copolymers were determined by gel permeation chromatography. Their glass‐transition temperatures (Tg's) were obtained by differential scanning calorimetry. The thermal stabilities of the copolymers were measured by thermogravimetric analysis. The structures of the copolymers were verified by 1H, 13C, and 29Si NMR as well as IR and UV spectroscopy. The copolymers displayed high thermal stabilities and a single Tg, indicating that phase separation between the two short blocks did not occur. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6146–6152, 2005
Thermoresponsive copolymers of methacrylic acid and poly(ethylene glycol) methyl ether methacrylate
Authors: Jones Janevieve A. , Novo Noel , Flagler Kendra , Pagnucco Christina D. , Carew Steve , Cheong Charles , Kong Xiang Z. , Burke Nicholas A. D. , Stöver Harald D. H.
Published: October 2005

Copolymers of methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) were prepared and their cloud points in aqueous solution were studied as a function of comonomer ratio, solution pH, and presence of hydrophobic comonomers. Under acidic conditions, the cloud point falls below 0 °C for copolymers with between 25% to 60% ether content, because of the formation of hydrophobic H‐bonded ether–acid complexes. The cloud point also decreases with solution pH. For equivalent ether to acid ratios, the cloud point decreases with decreasing PEG chain length, because of the presence of a larger number of hydrophobic methyl and methacrylate groups. Similarly, the cloud point decreases upon incorporation of hydrophobic comonomers such as butyl, lauryl, or glycidyl methacrylates. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6095–6104, 2005
Matrix‐assisted laser desorption/ionization time‐of‐flight analysis of the copolymerization reaction of an expanding monomer with a diepoxide
Authors: Miller Matthew D. , Holder Andrew J. , Guthrie Jill R. , Pinzino Charles S. , Chappelow Cecil C. , Eick J. David
Published: October 2005

In search of a composite with low stress and low shrinkage properties, this study includes matrix‐assisted laser desorption/ionization time‐of‐flight analysis of the photoinitiated cationic polymerization between an expanding monomer [1,5,7,11‐tetraoxaspiro[5.5]undecane (TOSU)] and a diepoxide [bisphenol A diglycidyl ether (BADGE)]. Past studies using NMR and differential scanning calorimetry analyses concluded copolymerization indirectly on the basis of deviations from homopolymer product data. This is the first study to provide direct evidence of copolymerization between these species. Unlike previous research, this study enables the identification of the TOSU homopolymer and the absence of the BADGE homopolymer, suggesting initial cationic activation of TOSU. In addition to peaks that correspond to the presumed mechanism for six‐membered TOSU polymerization, many peaks have a net gain or loss of cyclic carbonate in support of a new polymerization mechanism participating in the reaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5962–5970, 2005
Copolymers of 2,5‐bis[(4‐methoxyphenyl) oxycarbonyl]styrene with n‐butyl acrylate: Design, synthesis, and characterization
Authors: Gao Long‐Cheng , Pan Qi‐Wei , Yi Yi , Fan Xing‐He , Chen Xiao‐Fang , Zhou Qi‐Feng
Published: October 2005

A series of rod–coil diblock copolymers, consisting of poly{2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]styrene} as a rigid segment and poly(n‐butyl acrylate) as a flexible part, were successfully prepared through two inverse procedures by atom transfer radical polymerization. The copolymers were characterized by 1H NMR and gel permeation chromatography and had high molecular weights and relatively narrow polydispersities (polydispersity index < 1.20). All the block copolymers synthesized had two distinct glass‐transition temperatures according to differential scanning calorimetry. A polarizing optical microscopy investigation demonstrated the liquid crystallinity of the diblock copolymers. The self‐assembly behaviors in dilute solutions was studied by transmission electron microscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5935–5943, 2005
Cover Picture: Plasma Process. Polym. 8/2005
Authors: Beck Alison J. , Whittle Jason D. , Bullett Nial A. , Eves Paula , Mac Neil Sheila , McArthur Sally L. , Shard Alexander G.
Published: October 2005

Cover: The Figure shows the X‐ray photoelectron spectra of the nitrogen 1s core levels and the near edge X‐ray fine structure nitrogen K edge of plasma polymers and plasma co‐polymers prepared from allylamine and mixtures of acrylic acid and allylamine. Molecular models of allylamine, acrylic acid and allylammonium acrylate salt are shown to illustrate the chemistry. This is shown on a background of a micrograph of melanocytes cultured on a plasma polymer coating. The micrograph has been artificially colourised. Further details can be found in the Full Paper by A. J. Beck,* J. D. Whittle, N. A. Bullett, P. Eves, S. Mac Neil, S. L. McArthur, and A. G. Shard on page 641.
A tetrapeptide‐based method for polyproline II‐type secondary structure prediction
Authors: Vlasov Peter K. , Vlasova Anna V. , Tumanyan Vladimir G. , Esipova Natalia G.
Published: October 2005

We describe a new method for polyproline II‐type (PPII) secondary structure prediction based on tetrapeptide conformation properties using data obtained from all globular proteins in the Protein Data Bank (PDB). This is the first method for PPII prediction with a relatively high level of accuracy (∼60%). Our method uses only frequencies of different conformations among oligopeptides without any additional parameters. We also attempted to predict α‐helices and β‐strands using the same approach. We find that the application of our method reveals interrelation between sequence and structure even for very short oligopeptides (tetrapeptides). Proteins 2005. © 2005 Wiley‐Liss, Inc.
Mutagenesis at Pro309 of single‐chain urokinase‐type plasminogen activator alters its catalytic properties
Authors: Sun Ziyong , Liu Jian‐Ning
Published: October 2005

The charge of Lys300(c143) located within a flexible loop(297–313) of sc‐uPA has been identified as an important determinant for its high intrinsic activity. Mutations affecting the flexibility of the loop also modulate the intrinsic activity. Glu‐plasminogen activation by sc‐uPA is strongly promoted by fibrin fragment E but not fibrin fragment D‐dimer, whereas plasminogen activation by t‐PA is strongly promoted by fragment D‐dimer but not fragment E. To further investigate the effect of conformation changes in the flexible loop on catalytic properties of sc‐uPA, cassette mutations at Pro309(c152) were made and characterized. It was found that the activation of Pro309(c152) mutants by Lys‐plasmin was only moderately affected. In contrast, the intrinsic and two‐chain activities of Pro309(c152) mutants against S2444 were both significantly decreased. The two‐chain activities of these mutants against Glu‐plasminogen were also reduced in a range of 1.1‐ to 127‐fold. The mutations of Pro309(c152) to Trp/Phe and Arg/Asp more significantly affected both intrinsic and two‐chain activities, while only a moderate decrease in activity was found with mutations to Ala/Ser/Thr. In contrast to wild‐type sc‐uPA, plasminogen activation by Pro309(c152) mutants was found to be promoted by both fibrin fragment E and D‐dimer. In the presence of 2.0 μM D‐dimer, plasminogen activation by mutant Pro309(c152)→ His was promoted by 22‐fold, while only 2.0‐fold promotion was found with mutant Pro309(c152) → Gly. In conclusion, these findings demonstrated that conformation changes in the flexible loop of sc‐uPA not only affect its intrinsic and two‐chain activity, but also extend its promotion of plasminogen activation by fragment E to D‐dimer. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Integrating risk‐based inspection into risk management plans
Authors: Conley M.
Published: October 2005

Using risk as a metric for decisions, the right inspection can be applied at the right time. Risk‐based inspection is an approach for integrating risk metrics for both inspection‐type activities (such as preventative maintenance) and design‐type activities (such as safety systems to decrease risk).

Risk management plans are being developed for ammonia storage facilities to:

ensure the safety of employees, the public, and the environment

aid management in the decision‐making process to determine which activities achieve the most cost‐effective form of risk reduction

allow prioritization of even very different activities under the umbrella of good risk management practices.

© 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Simulation calculations of surface segregation for Au–Cu alloys using an analytic embedded atom model
Authors: Bangwei Zhang , Taglauer Edmund , Xiaolin Shu , Wangyu Hu , Huiqiu Deng
Published: October 2005

The key problem for applying the Monte Carlo (MC) method to segregation lies in the selection of an appropriate energy model for the simulations. Zhang et al. proposed a modified analytic embedded atomic method (MAEAM), which has been applied to a variety of fundamental problems in metals and alloys. We used this MAEAM and MC method for the simulations of segregation of AuCu and Au3Cu alloys. For the (100) surface, the calculations show that Au is enriched in the 1st layer (70 at% for AuCu, 99 at% for Au3Cu), while Cu is enriched in the 2nd layer (50–62 at% for AuCu, 35–48 at% for Au3Cu). The composition profiles are generally oscillating. For the (111) surface, we also found Au to be enriched in the 1st layer. However, Cu is not enriched in the 2nd layer, it reaches the bulk composition from 2nd to 4th layer. Au increases from 92 to 97 at% and 99 to 100 at% for Au3Cu(111) and (100), respectively, when the temperature varies from 1000 to 200 K, which is basically in agreement with the measurements for Au3Cu(100) by Taglauer et al. However, the Au concentration does not change for the AuCu alloy in the same temperature range. We also calculate the segregation energy, the simulation results agree qualitatively with the experimental data available. Our results demonstrate that the MAEAM model provides an effective means for simulating the segregation of alloys. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of the temperature‐dependent resistivity of La1–xTexMnO3
Authors: Guan Dong‐yi , Zhou Qing‐li , Jin Kui‐juan , Tan Guo‐tai , Chen Zheng‐hao , Lu Hui‐bin , Cheng Bo‐lin , Zhou Yue‐liang , He Meng , Han Peng , Yang Guo‐zhen
Published: October 2005

The resistivity ρ of La1–xTexMnO3 (x = 0.1, 0.14) is studied using a random resistor network, based on phase separation between ferromagnetic (FM) and paramagnetic (PM) domains. By considering the irregular shape of the domains, a revised method, which is used to find the shortest paths across the sample, leads to a good agreement between the simulated results and experiment data. Moreover, it is found that FM components increase with Te doping, leading to a reduction of the resistivity and a shift of the transition temperature. This method is proved to be valid and the phase separation scenario is shown theoretically to be good enough in describing the electrical conductivity of the doped manganese perovskites. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Substantial addition of PbO and liquid phase conversion during the final processing of (Bi,Pb)‐2223 thick film on Ag substrate and their influence on the microstructure and transport properties
Authors: Azzouz F. Ben , M'chirgui A. , Ben Salem M.
Published: October 2005

(Bi,Pb)‐2223 polycrystalline samples were made by introducing into the precursor powders various weight fractions of PbO during the final sintering cycle of a multi‐step preparation process. The influence of PbO addition on the melting temperature, high‐TC ((Bi,Pb)‐2223) phase formation, microstructure and transport property of samples was studied by DTA, XRD, SEM/EDX and electrical measurements. The results showed that the substantial addition of PbO up to 10 wt% promotes likely the stability and the abundance of the transient liquid phase during sintering, which in turn improved the grain growth an connectivity of (Bi,Pb)‐2223 phase, hence resulted in the improvement of transport current JC. The ultimate value of critical current density at 77 K in the self‐field is found to be 1080 A/cm2 in (Bi,Pb)‐2223 thick films on Ag substrate samples. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Estimation of gloss from rough surface parameters
Authors: Simonsen Ingve , Larsen Åge G. , Andreassen Erik , Ommundsen Espen , Nord‐Varhaug Katrin
Published: October 2005

Gloss is a quantity used in the optical industry to quantify and categorize materials according to how well they scatter light specularly. With the aid of phase perturbation theory, we derive an approximate expression for this quantity for a one‐dimensional randomly rough surface. It is demonstrated that gloss depends in an exponential way on two dimensionless quantities that are associated with the surface randomness: the root‐mean‐square roughness times the perpendicular momentum transfer for the specular direction, and a correlation function dependent factor times a lateral momentum variable associated with the collection angle. Rigorous Monte Carlo simulations are used to access the quality of this approximation, and good agreement is observed over large regions of parameter space. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Developments in the n‐electron valence state perturbation theory
Authors: Angeli Celestino , Borini Stefano , Cavallini Alex , Cestari Mirko , Cimiraglia Renzo , Ferrighi Lara , Sparta Manuel
Published: October 2005

A short summary of the n‐electron valence state perturbation theory (NEVPT) is provided, and the defects inherent in cases of quasi‐degeneration are underscored. A new version of the theory, called QD‐NEVPT, based on quasi‐degenerate perturbation theory, is presented. The new theory introduces an effective interaction among the zero‐order wave functions and overcomes the difficulties of state‐specific NEVPT. An application concerning the interaction among the π → π* and Rydberg singlets of formaldehyde is presented. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Lower semicontinuity and existence of minimizers in incremental finite‐strain elastoplasticity
Authors: Mielke A. , Müller S.
Published: October 2005

We study incremental problems in geometrically nonlinear elastoplasticity. Using the multiplicative decomposition Dφ= FelFpl we consider general energy functionals of the form

ℐ(φ, Fpl) = ∫ΩU(x, DφF‐1pl, Fpl, 𝒢(Fpl)) dx‐<ℓ, φ>,

which occur as the sum of the stored energy and the dissipation in one time step. Here 𝒢(Fpl) is the dislocation tensor which takes the form ${1\over {\rm det} F_{\rm pl}}$ curl3(Fpl),Fpl T in dimension d = 3.

Imposing the usual constraint det Fpl ≡ 1 and suitable growth and polyconvexity conditions on U we show that the minimum of ℐ is attained in the natural Sobolev spaces. Moreover, we are able to treat multiple time steps by controlling the stored and dissipated energies. We also address the relation of the incremental problem to the time‐continuous energetic formulation of elastoplasticity.
Comparative use of longline oysterbeds and adjacent tidal flats by waterbirds
Authors: CONNOLLY LINDA M. , COLWELL MARK A.
Published: October 2005

Commercial oyster Crassostrea spp. cultivation in intertidal habitats may degrade foraging habitat of waterbirds. Consequently, we compared species abundances, community similarity and diversity of waterbirds using longline oyster culture beds and adjacent control plots on tidal flats of Humboldt Bay, California. Abundances of most species differed significantly between treatments, with seven of 13 shorebirds Charadriiformes and three of four wading birds Ciconiiformes more abundant on longline plots. By contrast, Black-bellied Plover Pluvialis squatarola were more abundant on control plots. Marbled Godwit Limosa fedoa, Long-billed Curlew Numenius americanus and Dunlin Calidris alpina showed mixed results depending on location and Great Blue Heron Ardea herodias were more abundant only on one control plot. Community composition was similar on longline and control plots, although diversity (H′) was greater on longline plots. Varying species' responses to longline techniques may have been associated with interspecific differences in diet and foraging behaviour, and the impacts of longlines and oyster-harvesting on prey distribution. Overall, longlines did not negatively affect the foraging behaviour of most species, but the underlying causes for increased bird use may lead to impacts on other trophic levels and over a longer temporal scale.
Effects of deforestation and forest modification on understorey birds in Central Sulawesi, Indonesia
Authors: WALTERT M. , MARDIASTUTI A. , MÜHLENBERG MICHAEL
Published: October 2005

To estimate the potential of forest birds to persist in the increasingly deforested island of Sulawesi, we undertook a mist-net survey in the understorey of natural as well as modified forest (forest garden and heavily logged forest) at submontane elevations in Central Sulawesi. A total of forty 102 m mist-net lines were distributed over five 16 ha study sites. Two of the sites were situated in an extensively forested valley, and three in a valley with severely fragmented forest. Of 23 species captured, only seven were typical understorey dwellers of submontane forest, five of which are Sulawesi region endemics. Most were found in similar numbers in natural and modified forest, but one species was significantly more common in modified forest. Of the five endemics, two species were confined to, and one species was significantly more abundant in, the extensively forested valley compared with the severely deforested valley. Our results suggest that the conservation of the remaining submontane forest is crucial to the conservation of Central Sulawesi's understorey bird diversity, but that many Sulawesi endemics might be able to survive in modified habitats.
The effects of forest fragmentation on the population density and distribution of the globally Endangered Ibadan Malimbe Malimbus ibadanensis and other malimbe species
Authors: MANU SHIIWUA , PEACH WILL , BOWDEN CHRIS , CRESSWELL WILL
Published: October 2005

The Ibadan Malimbe Malimbus ibadanensis is a globally Endangered but poorly known forest species endemic to a small region of south-western Nigeria, where almost all forest has been severely fragmented. We carried out the first comprehensive survey of Ibadan Malimbe, and tested whether forest fragmentation is important in determining the distribution of this and related species in south-west Nigerian forest patches. Ibadan Malimbes were found at 19 of 52 sites surveyed but these were all clustered in a relatively small part of what appears to have been the former range. Unlike other malimbes, Ibadan Malimbes were less abundant in, or absent from, relatively isolated forest patches. Red-headed Malimbe M. rubricollis, Red-vented Malimbe M. scutatus and Crested Malimbe M. malimbicus were significantly more abundant in forest patches that retained vegetation characteristic of primary forest (i.e. tall trees and high tree densities). The average density of Ibadan Malimbes was 0.22 birds/ha (95% confidence limits (CL): 0.14–0.34) across all sites, but varied with degree of isolation, with densities of 0.06 birds/ha (0.03–0.14) in the 50% of fragments that were most isolated, compared with 0.33 (0.19–0.56) in the 50% of fragments that were least isolated. This gives a population estimate of 2,469 individuals (1,401–4,365) for the remaining potentially occupied forest area of 112 km2. Given that our survey covered most forest patches within the majority of the historical range of Ibadan Malimbe this can probably be considered a reasonable maximum world population estimate. Ibadan Malimbes appear to be restricted to a small number of relatively small forest patches most of which are highly vulnerable to further destruction, degradation and fragmentation. Conservation effort should urgently focus on the protection of currently occupied sites and increasing the number and extent of forest patches within and around the existing range.
Variability of particulate organic carbon concentration in the north polar Atlantic based on ocean color observations with Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS)
Authors: Stramska Malgorzata , Stramski Dariusz
Published: October 2005

We use satellite data from Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) to investigate distributions of particulate organic carbon (POC) concentration in surface waters of the north polar Atlantic Ocean during the spring–summer season (April through August) over a 6‐year period from 1998 through 2003. By use of field data collected at sea, we developed regional relationships for the purpose of estimating POC from remote‐sensing observations of ocean color. Analysis of several approaches used in the POC algorithm development and match‐up analysis of coincident in situ–derived and satellite‐derived estimates of POC resulted in selection of an algorithm that is based on the blue‐to‐green ratio of remote‐sensing reflectance Rrs (or normalized water‐leaving radiance Lwn). The application of the selected algorithm to a 6‐year record of SeaWiFS monthly composite data of Lwn revealed patterns of seasonal and interannual variability of POC in the study region. For example, the results show a clear increase of POC throughout the season. The lowest values, generally less than 200 mg m−3, and at some locations often less than 50 mg m−3, were observed in April. In May and June, POC can exceed 300 or even 400 mg m−3 in some parts of the study region. Patterns of interannual variability are intricate, as they depend on the geographic location within the study region and particular time of year (month) considered. By comparing the results averaged over the entire study region and the entire season (April through August) for each year separately, we found that the lowest POC occurred in 2001 and the highest POC occurred in 2002 and 1999.