bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic activities of polymer‐supported metal complexes in oxidation of phenol and epoxidation of cyclohexene
Authors: Gupta K. C. , Sutar A. K. 
Published: November 2007

AbstractThe metal complexes of N, N′‐bis (o‐hydroxy acetophenone) propylene diamine (HPPn) Schiff base were supported on cross‐linked polystyrene beads. The complexation of iron(III), copper(II), and zinc(II) ions on polymer‐anchored HPPn Schiff base was 83.4, 85.7, and 84.5 wt%, respectively, whereas the complexation of these metal ions on unsupported HPPn Schiff base was 82.3, 84.5, and 83.9 wt%. The iron(III) complexes of HPPn Schiff base were octahedral in geometry, whereas copper(II) and zinc(II) ions complexes were square planar and tetrahedral. Complexation of metal ions increased the thermal stability of HPPn Schiff base. Catalytic activity of metal complexes was tested by studying the oxidation of phenol and epoxidation of cyclohexene in the presence of hydrogen peroxide. The polymer‐supported HPPn Schiff base complexes of iron(III) ions showed 73.0 wt% conversion of phenol and 90.6 wt% conversion of cyclohexene at a molar ratio of 1:1:1 of substrate to catalyst and hydrogen peroxide, but unsupported complexes of iron(III) ions showed 63.8 wt% conversion for phenol and 83.2 wt% conversion for cyclohexene. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 93.1 and 98.3 wt%, respectively with supported HPPn Schiff base complexes of iron(III) ions but was lower with HPPn Schiff base complexes of copper(II) and zinc(II) ions. Activation energy for the epoxidation of cyclohexene and phenol conversion with unsupported HPPn Schiff base complexes of iron(III) ions was 16.6 kJ mol−1 and 21.2 kJ mol−1, respectively, but was lower with supported complexes of iron(III) ions. Copyright © 2007 John Wiley & Sons, Ltd.
Primary tumour expression of the cysteine cathepsin inhibitor Stefin A inhibits distant metastasis in breast cancer
Authors: Parker BS , Ciocca DR , Bidwell BN , Gago FE , Fanelli MA , George J , Slavin JL , Möller A , Steel R , Pouliot N , Eckhardt BL , Henderson MA , Anderson RL 
Published: November 2007

AbstractUsing the clinically relevant 4T1‐derived syngeneic murine model of spontaneous mammary metastasis to bone, we have identified the cysteine cathepsin inhibitor Stefin A as a gene differentially expressed in primary and metastatic mammary tumours. In primary tumours, Stefin A expression correlated inversely with metastatic potential in 4T1‐derived lines and was not detected in tumour cells in culture, indicating induction only within the tumour microenvironment. Enforced expression of Stefin A in the highly metastatic 4T1.2 cell line significantly reduced spontaneous bone metastasis following orthotopic injection into the mammary gland. Consistent with the mouse data, Stefin A expression correlated with disease‐free survival (absence of distant metastasis) in a cohort of 142 primary tumours from breast cancer patients. This was most significant for patients with invasive ductal carcinoma expressing Stefin A, who were less likely to develop distant metastases (log rank test, p = 0.0075). In a multivariate disease‐free survival analysis (Cox proportional hazards model), Stefin A expression remained a significant independent prognostic factor in patients with invasive ductal carcinoma (p = 0.0014), along with grade and progesterone receptor (PR) status. In human lung and bone metastases, we detected irregular Stefin A staining patterns, with expression often localizing to micrometastases (<0.2 mm) in direct contact with the stroma. We propose that Stefin A, as a cysteine cathepsin inhibitor, may be a marker of increased cathepsin activity in metastases. Using immunohistology, the cathepsin inhibitor was detected co‐expressed with cathepsin B in lung and bone metastases in both the murine model and human tissues. We conclude that Stefin A expression reduces distant metastasis in breast cancer and propose that this may be due to the inhibition of cysteine cathepsins, such as cathepsin B. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Synthesis of exfoliated polyamide 6,6/organically modified montmorillonite nanocomposites by in situ interfacial polymerization
Authors: Tarameshlou M. , Jafari S.H. , Khonakdar H.A. , Farmahini‐Farahani M. , Ahmadian S. 
Published: November 2007

AbstractPolyamide 6,6 (PA 6,6)/organically modified montmorillonite (OMMT) nanocomposites were prepared by a novel method, using direct interfacial polymerization of an aqueous hexamethylene diamine and a nonaqueous adipoyl chloride in dichloromethane solution containing different amounts of OMMT dispersed nanoparticles. The state of dispersion of OMMT in the PA 6,6 matrix was investigated by means of X‐ray diffraction, as well as transmission electronic microscopy. The results indicated that the OMMT nanoparticles were dispersed homogeneously and nearly exfoliated in the PA 6,6 matrix. The random arrangement of clay platelets in the PA 6,6 matrix, exfoliation, and intercalation of clays between the PA 6,6 matrix were distinguished. The amount of the incorporated OMMT in the PA 6,6 matrix was determined by means of TGA technique. Furthermore it was found that addition of a small amount of OMMT dramatically improved the thermal stability of PA 6,6. The TGA thermograms of all the synthesized nanocomposite samples showed an interesting unexpected lag in the weight loss at high temperatures, which could be another evidence for formation of fully exfoliated nanocomposites structures, with improved thermal stability. Nucleating effect of the OMMT nanoparticles and their influence on crystallization behavior of PA 6,6 was confirmed by DSC. Finally it is concluded that the in situ interfacial polycondensation is a suitable method for synthesis of nanocomposites with well dispersed structures and enhanced properties. POLYM. COMPOS., 28:733–738, 2007. © 2007 Society of Plastics Engineers
Surface modification of bagasse fibers by silane coupling agents through microwave oven and its effects on physical, mechanical, and rheological properties of PP bagasse fiber composite
Authors: Hashemi S.A. , Arabi H. , Mirzaeyan N. 
Published: November 2007

AbstractPolypropylene/bagasse fiber composites were prepared by compounding polypropylene (PP) with bagasse fibers as reinforcing filler. Surfaces of fibers were modified through the use of silane coupling agents (Vinyltrimethoxysilane and γ‐Glycidoxypropyltrimethoxysilane). The fiber coating was performed by mixing of silane with fibers and cured through microwave oven in presence of catalyst. It was found that modification of surface fiber will change the physical, mechanical, morphological, and rheological properties of composite. It was observed from scanning electron microscopy that fiber adhesion to matrix has been improved and so as dispersion. Addition of fibers increases the melt viscosity in unmodified fibers but reduced the melt viscosity for modified fibers and even the viscosity is lower at higher loading compared with unmodified fibers. The tensile strength and tensile modulus increased in modified fibers compared with the unmodified on the same loading, but elongation at break decreased. The effect of coupling agent on properties of filled PP depend on the content of coupling agents and optimum amount was achieve through measurement of water absorption. Two types of coupling agents were used, one as A‐171 [CH2CHSi (OCH3)3] and second one as A‐187 [CH2OCHCH2O (CH2)3Si(OCH3)], the first one shows better adhesion to the fibers and improvements in mechanical properties are much better compared with the second one. POLYM. COMPOS., 28:713–721, 2007. © 2007 Society of Plastics Engineers
Nonpolar interactions between trans‐membrane helical EGF peptide and phosphatidylcholines, sphingomyelins and cholesterol. Molecular dynamics simulation studies
Authors: Róg Tomasz , Murzyn Krzysztof , Karttunen Mikko , Pasenkiewicz‐Gierula Marta 
Published: November 2007

AbstractA molecular dynamics simulation study of four lipid bilayers with inserted trans‐membrane helical fragment of epithelial growth factor (EGF) receptor (EGF peptide) was performed. The lipid bilayers differ in their lipid composition and consist of (i) unsaturated phosphatidylcholine (palmitoyloleoylphosphatidylcholine, POPC), (ii) POPC and 20 mol% of cholesterol (Chol), (iii) sphingomyelin (SM) and 20 mol% of Chol, and (iv) SM and 50 mol% of Chol. Only 1 out of 26 residues in the EGF‐peptide sequence is polar (Thr). The hydrophobic thickness of each bilayer is different but shorter than the length of the peptide and so, due to hydrophobic mismatch, the inserted peptide is tilted in each bilayer. Additionally, in the POPC bilayer, which is the thinnest, the peptide loses its helical structure in a short three‐amino acid fragment. This facilitates bending of the peptide and burying all hydrophobic amino acids inside the membrane core (Figure 1(b)). Bilayer lipid composition affects interactions between the peptide and lipids in the membrane core. Chol increases packing of atoms relative to the peptide side chains, and thus increases van der Waals interactions. On average, the packing around the peptide is higher in SM‐based bilayers than POPC‐based bilayers but for certain amino acids, packing depends on their position relative to the bilayer center. In the bilayer center, packing is higher in POPC‐based bilayers, while in regions closer to the interface packing is higher in SM‐based bilayers. In general, amino acids with larger side chains interact strongly with lipids, and thus the peptide sequence is important for the pattern of interactions at different membrane depths. This pattern closely resembles the shape of recently published lateral pressure profiles [Ollila et alJ. Struct. Biol. DOI:10.1016/j.jsb.2007.01.012]. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Rapid identification of oxidation‐induced conformational changes by kinetic analysis
Authors: Venkatesh Sanjay , Tomer Kenneth B. , Sharp Joshua S. 
Published: November 2007

AbstractProtein oxidation by reactive oxygen species is known to result in changes in the structure and function of the oxidized protein. Many proteins can tolerate multiple oxidation events before altering their conformation, while others suffer gross changes in conformation after a single oxidation event. Additionally, reactive oxygen species have been used in conjunction with mass spectrometry to map the accessible surface of proteins, often after verification that the oxidations do not alter the conformation. However, detection of oxidation‐induced conformational changes by detailed kinetic oxidation analysis of individual proteolytic peptides or non‐mass spectrometric analysis is labor‐intensive and often requires significant amounts of sample. In this work, we describe a methodology to detect oxidation‐induced conformational changes in proteins via direct analysis of the intact protein. The kinetics of addition of oxygen to unmodified protein are compared with the kinetics of addition of oxygen to the mono‐oxidized protein. These changes in the rate of oxidation of the oxidized versus the non‐oxidized protein are strongly correlated with increases in the random coil content as measured by the molar ellipticity at 198 nm. This methodology requires only small amounts of protein, and can be done rapidly without additional sample handling or derivatization. Copyright © 2007 John Wiley & Sons, Ltd.
A UD factorization‐based nonlinear adaptive set‐membership filter for ellipsoidal estimation
Authors: Zhou Bo , Han Jianda , Liu Guangjun 
Published: November 2007

AbstractThe extended set‐membership filter (ESMF) for nonlinear ellipsoidal estimation suffers from numerical instability, computation complexity as well as the difficulty in filter parameter selection. In this paper, a UD factorization‐based adaptive set‐membership filter is developed and applied to nonlinear joint estimation of both time‐varying states and parameters. As a result of using the proposed UD factorization, combined with a new sequential and selective measurement update strategy, the numerical stability and real‐time applicability of conventional ESMF are substantially improved. Furthermore, an adaptive selection scheme of the filter parameters is derived to reduce the computation complexity and achieve sub‐optimal estimation. Simulation results have shown the efficiency and robustness of the proposed method. Copyright © 2007 John Wiley & Sons, Ltd.
Ecophilosophy as a philosophical underpinning of sustainable development
Authors: Piątek Zdzisława 
Published: November 2007

AbstractThe subjects considered here underpin the philosophical way in which the sustainable development concept is justified. In this context, the new branch of philosophy known as ecophilosophy is seen to have left behind the special pleading on behalf of humankind's exploitative attitudes towards Nature, in favour of considerations that – as they assign value to the biosphere per se – aim at the harmonious coexistence of the human species with all beings present in the biosphere.In the conceptual terms with which ecophilosophy has armed itself, sustainable development is the search for proper moderation in so far as human activity in the environment is concerned. A strategy for sustainable development is a mechanism needing to be incorporated into any further advancement of Western civilization.Ecophilosophy's chances of emerging are related to whether an inevitable, unavoidable antagonism between Nature and culture does or does not exist. It is the contention of this article that it does not. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
The surface of enargite after exposure to acidic ferric solutions: an XPS/XAES study
Authors: Fantauzzi M. , Elsener B. , Atzei D. , Lattanzi P. , Rossi A. 
Published: November 2007

AbstractEnargite surface reactivity in acidic ferric solutions simulating the acid mine drainage (AMD) environment has been investigated by X‐ray photoelectron (XPS) and X‐ray excited Auger electron spectroscopy (XAES) surface analysis. Natural enargite samples from a Peruvian mine with close to the nominal composition Cu3AsS4 have been analysed after cleavage and a 24 h exposure to 0.025 mol/l ferric acidic solutions.The results, based on the calculated modified Auger parameter α′, show that the chemical state of copper and arsenic in enargite does not change during immersion in acidic, oxidising solutions. The sulfur S 2p spectrum of enargite is characterized by two components, one at 162.0 ± 0.2 eV and the other at 163.5 ± 0.2 eV. The lower binding energy component (162.0 eV) is attributed to the sulfur atoms in enargite. Immersion does not change the chemical state of this compound. XPS/ARXPS measurements show the intensity of the higher binding energy component (163.5 ± 0.2 eV), located at the outermost surface of the reacted enargite, to increase after immersion in solutions. The chemical state plot suggests that this sulfur compound might be associated with the formation of a copper‐deficient enargite surface layer and not with elemental sulfur.Based also on the quantitative XPS determinations, the surface of the reacted enargite can be described as a layered structure: a thin copper‐deficient enargite layer (up to 0.7 nm) is formed on a slightly sulfur‐enriched enargite surface, the arsenic content remaining constant. Copyright © 2007 John Wiley & Sons, Ltd.
Reliability analysis for continuous measurements: Equivalence test for agreement
Authors: Yi Qilong , Wang P. Peter , He Yaohua 
Published: November 2007

AbstractIn tandem with the rapid development of medical technology, methods for assessing intrarater and interrater reliability or agreement across tools for continuous measurements have become an increasingly important research topic. Thus far, a number of reliability assessment methods have been proposed. Among them, the limits of agreement and repeatability coefficients were found to be the most useful tools for assessing reliability when measurements are on a continuous scale. However, both are considered as descriptive methods. The concepts of consistency or conformity require an equivalence test without which judgment would be subjective. In this paper we will extend the repeatability coefficient approach and propose an equivalence test that can be used to confirm the agreement between two or more measurement tools or assess interrater and intrarater reliability. Using this approach, a formula to calculate sample size will also be suggested and examples will be provided to illustrate the method. Copyright © 2007 John Wiley & Sons, Ltd.
A Bayesian approach to adjust for diagnostic misclassification between two mortality causes in Poisson regression
Authors: Stamey James D. , Young Dean M. , Seaman John W. 
Published: November 2007

AbstractResponse misclassification of counted data biases and understates the uncertainty of parameter estimators in Poisson regression models. To correct these problems, researchers have devised classical procedures that rely on asymptotic distribution results and supplemental validation data in order to estimate unknown misclassification parameters. We derive a new Bayesian Poisson regression procedure that accounts and corrects for misclassification for a count variable with two categories. Under the Bayesian paradigm, one can use validation data, expert opinion, or a combination of these two approaches to correct for the consequences of misclassification. The Bayesian procedure proposed here yields an operationally effective way to correct and account for misclassification effects in Poisson count regression models. We demonstrate the performance of the model in a simulation study. Additionally, we analyze two real‐data examples and compare our new Bayesian inference method that adjusts for misclassification with a similar analysis that ignores misclassification. Copyright © 2007 John Wiley & Sons, Ltd.
The economics of super‐tall towers
Authors: Watts Steve , Kalita Neal , Maclean Michael 
Published: November 2007

AbstractThis paper addresses global economic factors influencing the decisions leading to the development of super‐tall towers, including population growth and urbanization, economic cycles and the ‘Skyscraper Index’, regulation and ‘regulatory tax’, and resource availability. The project economics of individual developments are then explored with respect to construction costs. The development, design and construction challenges that impact on cost are also discussed. Furthermore, a breakdown of costs is given in the form of an indicative cost model (for a central London landmark tower) from cost data collected by Davis Langdon in the course of their work as construction consultants. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of Uptake Characteristics and Prognostic Value of 201Tl and 18F‐FDG in Esophageal Cancer
Authors: Chung Hyun Woo , Lee Kyung‐Han , Lee Eun Jeong , Lee Su Jin , Cho Young Seok , Choi Joon Young , Shim Young Mog , Kim Kwhanmien , Kim Byung‐Tae 
Published: November 2007

AbstractBackgroundPatients with esophageal cancer often undergo 201Tl myocardial imaging for preoperative risk evaluation, thereby providing an excellent opportunity to assess tumor handling of 201Tl. We thus compared the characteristics of 201Tl and 18F‐FDG uptake by esophageal cancer and further investigated their prognostic values.MethodsThe study included 100 newly diagnosed esophageal cancer patients who underwent preoperative 201Tl SPECT and 18F‐FDG PET exams. Tumor to mediastinal uptake (T/M) ratio and retention index (RI) of 201Tl, tumor 18F‐FDG pSUV, tumor size, location, and stage were assessed. Survival analysis was performed for disease‐free survival using the Kaplan–Meier method. Cox proportional hazard models were used to determine independent risk factors.Results201Tl SPECT and 18F‐FDG PET visualized the primary tumor in 85/100 (85.0%) and 91/100 (91.0%) patients, respectively (p = 0.03). There were close correlations between early and delayed 201Tl T/M ratios (r = 0.83, p < 0.0001) and between T/M ratios and 18F‐FDG pSUV (r = 0.56 and 0.57, respectively, both p < 0.0001). Both T/M ratios and 18F‐FDG pSUV correlated significantly with tumor stage (ρ = 0.45, 0.40, and 0.59, respectively, all p < 0.0001). Survival analysis revealed tumor size, 201Tl negative tumors, 18F‐FDG negative tumors, delayed 201Tl T/M ratio, RI, stage, and 18F‐FDG pSUV to be significant univariate predictors for disease‐free survival. Multivariate survival analysis showed stage (p = 0.02) to be a significant independent prognostic predictor.ConclusionsIn patients with esophageal cancer, assessment of tumor 201Tl uptake, as with 18F‐FDG, may provide potentially useful information regarding tumor characteristics.
Fourier Transform Near Infrared Spectroscopy: A Newly Developed, Non‐Invasive Method To Measure Body Fat
Authors: Azizian H. , Kramer J. K. G. , Heymsfield S. B. , Winsborough S. 
Published: November 2007

AbstractAn FT‐NIR technique is reported to provide a fast, accurate and low cost method of determining in‐vivo human body fat content. The body fat content of 353 healthy subjects (154 males and 199 females) of various height, weight, and age were measured by FT‐NIR and compared to 420 subjects investigated by magnetic resonance imaging (MRI). The procedure involved scanning each subject's upper ear that provided a necessary reflectance surface and proved representative of the subject's subcutaneous fat content. The average FT‐NIR spectrum was compared to a reference mixture with known and similar fat content and composition to that of humans. The FT‐NIR response was incorporated into an empirical equation using the ratio of subcutaneous to total body fat from MRI data, taking into account the subject's gender, height, weight and age. The results on the two data sets were similar and demonstrated that the FT‐NIR technique can be used to obtain a measure of the body fat content of individuals, similar to that using MRI. In addition, the FT‐NIR was used to more accurately monitor the fat content of sleep apnea patients.
The Percentage of n‐3 Highly Unsaturated Fatty Acids in Total HUFA as a Biomarker for Omega‐3 Fatty Acid Status in Tissues
Authors: Stark Ken D. 
Published: November 2007

AbstractA blood biomarker of omega‐3 fatty acid intake and tissue status could serve as a modifiable risk factor for cardiovascular disease. The percentage of omega‐3 highly unsaturated fatty acid (HUFA ≥ 20 carbons and ≥3 double bonds) in the total HUFA pool (the n‐3 HUFA score) was examined as a potential blood biomarker of omega‐3 fatty acids in tissues. The fatty acid composition of total lipid extracts (TLE) and phospholipid (PL) fractions were determined for plasma and erythrocytes samples of human subjects (n = 20) and the n‐3 HUFA score and the sum of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were compared. Omega‐3 fatty acids in blood and tissues of rats (n = 31) and pigs (n = 48) were also determined and the associations were compared. The n‐3 HUFA score is more consistent across plasma and erythrocytes, with strong correlations between TLE and PL in plasma (r = 0.93) and erythrocytes (r = 0.94). The n‐3 HUFA score was less variable and blood levels correlated strongly with various animal tissues. The n‐3 HUFA score is a useful blood biomarker that does not require the isolation of the PL class thereby supporting high throughput analyses. The strength of association between the n‐3 HUFA score and disease risk needs to be examined.