bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Catalysts
Authors: Albers Peter
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Sulfate Metabolism in Mycobacteria
Authors: Schelle Michael W. , Bertozzi Carolyn R.
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mechanisms of Neuroprotective Effects of Therapeutic Acetylcholinesterase Inhibitors Used in Treatment of Alzheimer′s Disease
Authors: Takatori Yuki
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Herbicide Residues in the Environment
Authors: Dagnac Thierry , Jeannot Roger
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Analysis of Urea Derivative Herbicides in Water and Soil
Authors: Bogialli Sara , Curini Roberta , Di Corcia Antonio , Nazzari Manuela
Published: December 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Evaluation of an inflammation‐based prognostic score in patients with metastatic renal cancer
Authors: Ramsey Sara , Lamb Gavin W. A. , Aitchison Michael , Graham John , McMillan Donald C.
Published: December 2006

BACKGROUND.

Recently, it was shown that an inflammation‐based prognostic score, the Glasgow Prognostic Score (GPS), provides additional prognostic information in patients with advanced cancer. The objective of the current study was to examine the value of the GPS compared with established scoring systems in predicting cancer‐specific survival in patients with metastatic renal cancer.

METHODS.

One hundred nineteen patients who underwent immunotherapy for metastatic renal cancer were recruited. The Memorial Sloan‐Kettering Cancer Center (MSKCC) score and the Metastatic Renal Carcinoma Comprehensive Prognostic System (MRCCPS) score were calculated as described previously. Patients who had both an elevated C‐reactive protein level (>10 mg/L) and hypoalbuminemia (<35 g/L) were allocated a GPS of 2. Patients who had only 1 of those 2 biochemical abnormalities were allocated a GPS of 1. Patients who had neither abnormality were allocated a GPS of 0.

RESULTS.

On multivariate analysis of significant individual factors, only calcium (hazard ratio [HR], 3.21; 95% confidence interval [95% CI], 1.51–6.83; P = .002), white cell count (HR, 1.66; 95% CI, 1.17–2.35; P = .004), albumin (HR, 2.63; 95% CI, 1.38–5.03; P = .003), and C‐reactive protein (HR, 2.85; 95% CI; 1.49–5.45; P = .002) were associated independently with cancer‐specific survival. On multivariate analysis of the different scoring systems, the MSKCC (HR, 1.88; 95% CI, 1.22–2.88; P = .004), the MRCCPS (HR, 1.42; 95% CI, 0.97–2.09; P = .071), and the GPS (HR, 2.35; 95% CI, 1.51–3.67; P < .001) were associated independently with cancer‐specific survival.

CONCLUSIONS.

An inflammation‐based prognostic score (GPS) predicted survival independent of established scoring systems in patients with metastatic renal cancer. Cancer 2007. © 2006 American Cancer Society.
The Effect of Catalyst Loading in Copper‐Catalyzed Cyclohexane Functionalization by Carbene Insertion
Authors: Caballero Ana , Díaz‐Requejo M. Mar , Trofimenko Swiatoslaw , Belderraín Tomás R. , Pérez Pedro J.
Published: December 2006

A study of the variables that affect the insertion of the :CHCO2Et group (formed from ethyl diazocetate, EDA) into the C–H bonds of cyclohexane in the presence of a TpxCu complex as the catalyst (Tpx = trispyrazolylborate ligand) has demonstrated an anomalous effect of the catalyst loading. The use of low concentrations of catalyst produces an increase in the yield of the C–H activation product ethyl cyclohexaneacetate. This effect has also been found in the case of other less elaborated catalysts such as [BpBr3Cu] or [(bipy)2Cu][I]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis of Both Enantiomers of Conduritol C Tetraacetate and of meso‐Conduritol D Tetraacetate by Oxidation of Benzoquinone Bis(ethylene acetal)
Authors: Lang Martin , Ziegler Thomas
Published: December 2006

Epoxidation of p‐benzoquinone bis(ethylene acetal) (1) with m‐chloroperbenzoic acid or hydrogen peroxide/benzonitrile afforded corresponding monoepoxide 2, which was converted into p‐benzoquinone mono(ethylene acetal) monoepoxide 5 with perchloric acid. Dihydroxylation of 1 with osmium tetroxide or ruthenium trichloride/sodium periodate afforded corresponding cis‐diol 6, which was subsequently acetylated to give diacetate 7. One ethyleneacetal moiety in 7 could be selectively hydrolyzed with silica gel/ferric chloride under solvent‐free conditions to give ketone 8, which, upon reduction with sodium borohydride and subsequent acetylation of the formed alcohol group, afforded two diastereomeric triacetates 10. Hydrolysis of the remaining acetal functions in the two diastereomers 10, followed by reduction of the second carbonyl group as described above, afforded racemic conduritol C and meso‐conduritol D tetraacetates 12 and 13, respectively. Enzymatic resolution of the racemic arabino‐configured triacetate 10 with Lipozym failed, while the ribo‐configured counterpart reacted smoothly to give enantiomerically pure D‐ribo‐ and L‐ribo‐configured triacetates 10. The latter pair of enantiomerically pure triacetates were converted into both enantiomers of conduritol C tetraacetate 13 as described for the racemic compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Breast cancer mortality after screening mammography in British Columbia women
Authors: Coldman Andrew , Phillips Norm , Warren Linda , Kan Lisa
Published: December 2006

Mammographic screening is a proven method for the early detection of breast cancer. The authors analyzed the impact of service mammographic screening on breast cancer mortality among British Columbia women who volunteered to be screened by the Screening Mammography Program of British Columbia. A cohort of women having at least one mammographic screen by Screening Mammography Program of British Columbia between the ages of 40 and 79 in the period 1988–2003 was identified. All cases and deaths from breast cancer occurring in British Columbia were identified from the British Columbia Cancer Registry and linked to the screening cohort. Expected deaths from breast cancer in the cohort were calculated using incidence and survival rates for British Columbia women not in the cohort. Adjustment was made for age and socioeconomic status of their area of residence at time of diagnosis. The breast cancer mortality ratio was calculated by dividing observed by expected breast cancer deaths. The mortality ratio (95% confidence interval) was 0.60 (0.55, 0.65) for all ages combined (p < 0.0001). The mortality ratio in women aged 40–49 at first screening was 0.61 (0.52, 0.71), similar to that in women over 50 (p = 0.90). Exclusion of mortality associated with breast cancers diagnosed after age 50 in women starting screening in their 40s increased the mortality ratio to 0.63 (0.52, 0.77), but it remained statistically significant. Correction for self‐selection bias using estimates from the literature increased the mortality ratio for all ages to 0.76. Mammographic screening at all ages between 40 and 79 reduced subsequent mortality rates from breast cancer. © 2006 Wiley‐Liss, Inc.
Diffuse functions in natural bond orbital analysis
Authors: Goodman Lionel , Sauers Ronald R.
Published: December 2006

We show that diffuse function augmentation of Pople basis sets at the 6‐311G RHF and B3LYP levels strongly impact conclusions drawn from natural bond orbital (NBO) analysis. The large spatial extent of high quantum number Rydberg orbitals introduced by augmentation contribute importantly to the valence space of neighboring atoms due to the likely inadequacy of the 311 valence functions. In contrast, lesser anomalies are found for augmentation of double zeta type 6‐31G. The energetic anomalies found for bond and antibond NBO descriptions, made nonlocal by augmentation, are most serious for molecules with four or more heavy atoms. For these cases augmentation can lead to nonphysical results. NBO results using Dunning‐type correlation consistent orbitals exhibit much weaker basis set dependence than those using the Pople basis sets.© 2006 Wiley Periodicals, Inc. J Comput Chem 2007
Mechanical strain induces a persistent upregulation of syndecan‐1 expression in smooth muscle cells
Authors: Julien Matheau A. , Haller Carolyn A. , Wang Peiyi , Wen Jing , Chaikof Elliot L.
Published: December 2006

Syndecan‐1 belongs to a family of transmembrane proteoglycans, acts as a coreceptor for growth factor binding, as well as cell–matrix and cell–cell interactions, and is induced in smooth muscle cells (SMCs) following balloon catheter injury. In this report, we investigated syndecan‐1 expression in SMCs in response to several distinct biomechanical force profiles and the related syndecan shedding response. Syndecan‐1 mRNA expression increased in response to 5% and 10% cyclic strain (24 h: 206 ± 40% and 278 ± 33%, respectively, P < 0.05) when compared to unstrained controls. When subjected to 10% cyclic strain for periods of up to 48 h, syndecan‐1 mRNA levels remained elevated at 294 ± 31%. Notably, the SMC mechanosensor mechanism remained responsive after an initial 24 h “preconditioning” period, as evident by a fivefold increase in syndecan‐1 gene expression following a change in cyclic stress from 10% to 20% (48 h: 516 ± 55%, P < 0.05). Of note, similar behavior was not observed in an analysis of syndecan‐2 mRNA levels. Commensurate with mRNA responses, mechanical stress induced an increase in cell‐associated syndecan‐1 protein levels with an associated increase in protein shedding. Given the varied functions of syndecan‐1, stress‐induced effects on SMC syndecan‐1 expression and shedding may represent an additional component of the pro‐inflammatory, growth‐stimulating pathways that are activated in response to changes in the mechanical microenvironment of the vascular wall. Syndecan‐1 expression is uniquely influenced by changes in the phase and magnitude of the local stress field. J. Cell. Physiol. 211: 167–173, 2007. © 2006 Wiley‐Liss, Inc.
Issues relating to the common origin of two Byzantine miniatures:in situexamination with Raman spectroscopy and optical microscopy
Authors: Daniilia Sister , Andrikopoulos Konstantinos S.
Published: December 2006

A large number of Byzantine illustrated manuscripts—precious monuments of the world’s cultural heritage—are preserved in numerous museums and monasteries around the globe. Hitherto no systematic study employing diagnostic methods has been undertaken either to identify their materials or to reveal the particularities of their painting technique, let alone substantiate their origin, authenticity and chronology.

This paper presents the results of research undertaken on two full‐page medieval miniatures painted on isolated sheets of paper. One depicts the evangelist Matthew and the other an eagle (symbolic of the evangelist John the Theologian). The folios are preserved in the sacristy of the Holy Monastery of Simonopetra on Mount Athos and it is supposed that they originally belonged to an unidentified Gospel manuscript of the 12th century. By applying optical microscopy and Raman spectroscopy, it became possible to address the issue of the miniatures' common origin.

The palette used for the image of Saint Matthew was found to comprise eight finely ground pigments:lapis lazuli, cinnabar, orpiment, yellow ochre, haematite, green earth, carbon black and lead white, while in the miniature of the eagle the same pigments (aside from green earth) were used. Exhaustive study has revealed significant similarities in the color palette and painting technique. Technical particularities adapted to the demands of miniature painting have been also observed, revealing an experienced and highly talented artist. A thorough comparison of the two miniatures confirmed that they belong to the same codex and hence must be the work of one and the same painter. Copyright © 2006 John Wiley & Sons, Ltd.
Fabrication of a range of SERS substrates on nanostructured multicore optical fibres
Authors: White D. J. , Mazzolini A. P. , Stoddart P. R.
Published: December 2006

An effective method for producing arrays of nanoscale triangles, rods and wells on the distal end of a silica optical fibre is presented. The structures are produced by applying a wet‐etch procedure to drawn‐down imaging fibres. Structural variation is achieved by altering the final diameter of the drawn fibre. Feature sizes of less than 100 nm can be readily achieved in this way. When coated with silver, surface‐enhanced Raman scattering enhancement factors of over 106 can be achieved, depending on the size and shape of the structures present. Copyright © 2006 John Wiley & Sons, Ltd.
Raman spectroscopy of uranopilite of different origins—implications for molecular structure
Authors: Frost Ray L. , Čejka Jiří , Weier Matt L. , Martens Wayde N. , Ayoko Godwin A.
Published: December 2006

Uranopilite, [(UO2)6(SO4)O2(OH)6(H2O)6](H2O)8, the composition of which may vary, can be understood as a complex hydrated uranyl oxyhydroxy sulfate. The structure of uranopilite from different locations has been studied by Raman spectroscopy at 298 and 77 K. A single intense band at 1009 cm−1 assigned to the ν1 (SO4)2− symmetric stretching mode shifts to higher wavenumbers at 77 K. Three low‐intensity bands are observed at 1143, 1117 and 1097 cm−1. These bands are attributed to the (SO4)2− ν3 anti‐symmetric stretching modes. Multiple bands provide evidence that the symmetry of the sulfate anion in the uranopilite structure is lowered. Three bands are observed in the region 843 to 816 cm−1 in both the 298 and 77 K spectra and are attributed to the ν1 symmetric stretching modes of the (UO2)2+ units. Multiple bands prove the symmetry reduction of the UO2 ion. Multiple OH stretching modes prove a complex arrangement of OH groupings and hydrogen bonding in the crystal structure. A series of infrared bands not observed in the Raman spectra are found at 1559, 1540, 1526 and 1511 cm−1 attributed to δ UOH bending modes. U‐O bond lengths in uranyl and OH/dotbondO bond lengths are calculated and compared with those from X‐ray single crystal structure analysis. The Raman spectra of uranopilites of different origins show subtle differences, proving that the spectra are origin‐ and sample‐dependent. Hydrogen‐bonding network and its arrangement in the crystal structure play an important role in the origin and stability of uranopilite. Copyright © 2006 John Wiley & Sons, Ltd.
Line shape analyses on the CO stretching bands of acetone using a vibrational coupling model
Authors: Kobayashi Kaori , Kanesaka Isao
Published: December 2006

The line shapes of the polarized and depolarized Raman bands of the CO stretching of acetone, as well as the infrared band, are analyzed on the basis of the vibrational coupling model. The analytical procedures are described in detail. Satisfactory agreement between the observed and simulated spectra is obtained using almost the same coupling scheme for the three types of spectra. The orientational correlation between the coupled oscillators is discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Spectroscopic and computational studies on self‐assembly complexes of bis(pyrrol‐2‐ ylmethyleneamine) ligands linked by alkyl spacers with Cu(II)
Authors: Li Wei , Wang Yibo , Yang Lanying , Szeghalmi Adriana , Ye Yong , Ma Jinshi , Luo Mingdao , Hu Ji‐ming , Kiefer Wolfgang
Published: December 2006

Bis(pyrrol‐2‐ylmethyleneamine) ligands and their mononuclear monomeric and dinuclear dimeric self‐assembly complexes with Cu(II) were investigated by means of IR and Raman spectroscopies and density functional theory. The ground‐state geometries were calculated by using the BeckeLeeYangParr composite exchange‐correlation functional (B3LYP) and a combined basis set (LanL2DZ for Cu; 6–31G(d) for C, H, N), and they were compared with the single‐crystal X‐ray diffraction (XRD) structures. The DFT‐calculated CuN bond lengths are generally higher by 0.001–0.040 Å than those determined through XRD. The vibrational spectra were also calculated at the same level of theory for the optimized geometries. The calculated wavenumbers were scaled by a uniform scaling factor and compared with the experimental fundamentals. The predicted spectra are in good agreement with the experimental ones with the deviations generally less than 30 cm−1. In comparison with the spectra of the ligands, the coordination effect shifts the υ(CN) wavenumber by about 50 cm−1 toward a lower value. Because of the weak intermolecular CH···Cu hydrogen bond, the CuN stretching mode is shifted toward a lower wavenumber. Copyright © 2006 John Wiley & Sons, Ltd.
Nanomechanics of single keratin fibres: A Raman study of the α‐helix →β‐sheet transition and the effect of water
Authors: Paquin Raphaël , Colomban Philippe
Published: December 2006

The use of micro‐Raman spectroscopy, through chemical‐bond, nano‐scale probes, allows the changes in conformations (α‐helix →β‐sheet), chain orientation, breakage of disulfide bonds (20%) and the increase of intra‐ and inter‐chain distances during the application of stress to be distinguished. The combination of micro‐Raman spectroscopy and a Universal Fibre Tester allows a quantitative measurement of the extension of chemical bonds in the peptide chain during loading. The nano‐structural transformations of keratin during strain of human hair in a dry environment (40–60% relative humidity) and saturated with water have been studied. Water permits the sliding of the chains and decreases the bond energy of the hair. Spectral analyses and 2D correlation are two coherent and independent methods to follow the structural nano‐mechanical (Raman) and micro‐mechanical (strain/stress) analyses, and confirm the validity of the experimental results, tools and principles used, as well as the agreement with the structural model of keratin fibres described by Chapman and Hearle. Copyright © 2006 John Wiley & Sons, Ltd.
Cover Picture: Macromol. Biosci. 12/2006
Authors: Chitkara Deepak , Shikanov Ariella , Kumar Neeraj , Domb Abraham J.
Published: December 2006

Cover: An image of an injectable P(RA:SA) polymer specimen, obtained using SEM, showed a reversible unique three‐dimensional physical structure that appeared upon exposure to buffer/water removal. This structure may be explained by hydrogen bonding between the carboxylic end groups resulting from slow hydrolytic degradation and the surrounding water molecules. Further details can be found in the article by D. Chitkara, A. Shikanov, N. Kumar,* and A. J. Domb on page 977.
N‐Isopropylacrylamide/2‐Hydroxyethyl Methacrylate Star Diblock Copolymers: Synthesis and Thermoresponsive Behavior
Authors: Cao Zhiqiang , Liu Wenguang , Ye Guixiang , Zhao Xiaoli , Lin Xiaoze , Gao Peng , Yao Kangde
Published: December 2006

Summary: Tri‐arm star diblock copolymers, poly(2‐hydroxyethyl methacrylate)‐block‐poly(N‐isopropylacrylamide) [P(HEMA‐b‐NIPAAm)] with PHEMA and PNIPAAm as separate inner and outer blocks were synthesized via a two‐step ATRP at room temperature. The formation, molecular weight and distribution of polymers were examined, and the kinetics of the reaction was monitored. The PDI of PHEMA was shown to be lower, indicating well‐controlled polymerization of trifunctional macro‐initiator and resultant star copolymers. The thermoresponsive behavior of diblock copolymer aqueous solution were studied by DSC, phase diagrams, temperature‐variable 1H NMR, TEM and DLS. The results revealed that introducing a higher ratio of HEMA into copolymers could facilitate the formation of micelles and the occurrence of phase transition at lower temperatures. TEM images showed that I‐(HEMA40‐NIPAAm320)3 solutions developed into core‐shell micelles with diameters of approximately 100 nm. I‐(HEMA40‐NIPAAm320)3 was used as a representative example to elucidate the mechanism underlying temperature‐induced phase transition of copolymer solution. In this study we proposed a three‐stage transition process: (1) separately dispersed micelles state at ≈17–22 °C; (2) aggregation and fusion of micelles at ≈22–29 °C; (3) sol‐gel transition of PNIPAAm segments at ≈29–35 °C, and serious syneresis of shell layers.

Molecular architecture of Poly(HEMA‐b‐NIPAAm).

magnified image

Molecular architecture of Poly(HEMA‐b‐NIPAAm).
Binary Blends of Polymer Semiconductors: Nanocrystalline Morphology Retards Energy Transfer and Facilitates Efficient White Electroluminescence
Authors: Alam Maksudul M. , Jenekhe Samson A.
Published: December 2006

Summary: Blends of poly(9,9‐dioctylfluorene) (PFO) and poly(2‐methoxy‐5(2′‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene) (MEH‐PPV) were found to phase separate into 40–50 nm crystalline PFO domains and to exhibit efficient white electroluminescence when the composition is below 30 wt.‐% MEH‐PPV. The 5 wt.‐% nanocrystalline blends had a luminance of 4 000 cd · m−2, an external quantum efficiency of 3.1%, and a current efficiency of 3.7 cd · A−1. Transmission electron microscopy, electron diffraction, and atomic force microscopy of blends with higher MEH‐PPV content and the two homopolymers showed them to be amorphous. Only orange‐red electroluminescence, characteristic of MEH‐PPV, was observed from the amorphous blends due to efficient energy transfer from PFO. These results demonstrate that energy transfer processes in binary PFO:MEH‐PPV blends and light‐emitting devices based on them can be controlled through the morphology and composition.

TEM image of a PFO:MEH‐PPV blend.

magnified image

TEM image of a PFO:MEH‐PPV blend.
Mortality in patients with Parkinson's disease treated by stimulation of the subthalamic nucleus
Authors: Schüpbach Michael W.M. , Welter Marie Laure , Bonnet Anne Marie , Elbaz Alexis , Grossardt Brandon R. , Mesnage Valerie , Houeto Jean Luc , Maltête David , Mallet Luc , Rocca Walter A. , Mallet Alain , Agid Yves
Published: December 2006

Subthalamic nucleus (STN) stimulation improves motor disability and quality of life in patients with advanced Parkinson's disease (PD). Short‐term mortality is low, but little is known about long‐term mortality. We assessed mortality and causes of death in 171 consecutive PD patients treated by STN stimulation. Surgery was performed after a median lagtime of 13 years from PD onset at a median age of 57 years. The median follow‐up after surgery was 41 months. Sixteen patients died 8 to 83 months after neurosurgery. Poorer cognitive function was the only predictive factor for mortality (standardized mortality ratio = 2.9; 95% confidence interval [CI], 1.6–4.7; P < 0.0001). Based on a historical comparison of 118 operated patients with 39 nonoperated patients from a different population, survival among operated patients was not better (hazard ratio = 1.2; 95% CI, 0.7–2.1). © 2006 Movement Disorder Society
Complete assignments of 1H and 13C NMR spectroscopic data for two new triterpenoid saponins from Ilex hainanensis
Authors: Zhou Sixiang , Yang Junshan , Liu Fucheng , Tu Pengfei
Published: December 2006

Two novel unsaturated E‐ring pentacyclic triterpenoid saponins, ilexhainanoside A and ilexhainanoside B, were isolated from the leaves of Ilex hainanensis. Their chemical structures were determined by MS, NMR spectroscopy and chemical analysis. Complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, ROESY and 1H–1H COSY). Copyright © 2006 John Wiley & Sons, Ltd.
Conformational study of 2‐arylazo‐1‐vinylpyrroles
Authors: Rusakov Yury Yu. , Krivdin Leonid B. , Senotrusova Elena Yu. , Schmidt Elena Yu. , Vasiltsov Alexander M. , Mikhaleva Albina I. , Trofimov Boris A. , Dyachenko Oleg A. , Chekhlov Anatolii N. , Kazheva Olga N.
Published: December 2006

Conformational study of 2‐phenylazo‐1‐vinylpyrrole and 2‐(4‐bromophenyl)azo‐5‐methyl‐1‐vinylpyrrole was performed on the basis of the experimental measurements and high‐level ab initio calculations of their 13C13C and 13C1H spin–spin coupling constants, showing marked stereochemical behaviour upon the internal rotation of the vinyl group and the pyrrolyl moiety. In liquid phase, both compounds were found to adopt predominant s‐trans‐s‐trans conformation with the noticeable population (ca. 30%) of the higher‐energy s‐cis‐s‐trans conformation in the latter compound. As follows from the X‐ray data, 2‐phenylazo‐1‐vinylpyrrole crystallizes in s‐trans‐s‐trans conformation while the crystalline molecular structure of 2‐(4‐bromophenyl)azo‐5‐methyl‐1‐vinylpyrrole is s‐cis‐s‐trans. Copyright © 2006 John Wiley & Sons, Ltd.
Low frequency tangential filtering decomposition
Authors: Achdou Y. , Nataf F.
Published: December 2006

For block‐tridiagonal systems of linear equations arising from the discretization of partial differential equations, a composite preconditioner is proposed and tested. It combines a classical ILU0 factorization for high frequencies with a tangential filtering preconditioner. The choice of the filtering vector is important: the test‐vector is the Ritz eigenvector corresponding to the approximate lowest eigenvalue, obtained after a limited number of iterations of a ILU0 preconditioned Krylov method. Numerical tests are carried out for this method. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and characterization of poly(higher‐α‐olefin)s with a nickel(α‐diimine)/methylaluminoxane catalyst system: Effect of chain running on the polymer properties
Authors: Subramanyam Ummadisetty , Sivaram Swaminathan
Published: December 2006

Homopolymerization of octadecene‐1 at different reaction conditions has been studied. Significant chain running can be seen at higher polymerization temperatures. Interestingly, insertion of octadecene‐1 into a sterically hindered nickel‐cation/carbon (secondary) bond is observed. The microstructure of the polymer was established using NMR spectroscopy. The effects of chain running on polymer melting, crystallization behavior, and dynamic mechanical thermal properties were studied using DSC and DMTA. The extent of chain running (i.e., 2,ω‐, 1,ω‐enchainments) decreases with an increase in the carbon number of α‐olefins. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 191–210, 2007
Collagen models as a probe in the decay of works of art: synthesis, conformation and immunological studies
Authors: Zevgiti Stella , Sakarellos Constantinos , Sakarellos‐Daitsiotis Maria , Ioakimoglou Eleni , Panou‐Pomonis Eugenia
Published: December 2006

Proteinaceous substances such as collagen, casein and albumin have been widely used as binding media in a variety of works of art. Damages of these ‘sensitive’ materials, mainly caused of the influence of the environment, are responsible for the overall decay of works of art, and their identification is essential to understand ancient technologies, determine the extent of deterioration and help in future restoration and preservation processes. The most commonly used techniques for the identification of proteinaceous binding media are staining techniques, chromatography, spectrometry and immunological methods, although for the latter no systematic studies have been carried out until now. Aiming at contributing to the development of a reliable and reproducible immunoassay for the evaluation of the collagen‐based decay of works of art, sequential polypeptides (Pro‐X‐Gly)n where X represents amino acid residues Val, Lys, Glu and (Hyp‐Val‐Gly)n were prepared as models of collagen fragments derived from artificially and naturally aged animal collagens. Conformational studies of the polypeptides by CD revealed the occurrence of polyproline II‐like structures comparable with those of collagen. Polypeptides and collagen I were administered to animals, and the induced antibodies were used for the immunochemical detection and differentiation of collagen and collagen fragments. The combined application of (i) anti‐collagen antibodies, which strongly interact with native collagen, but poorly recognized by artificially aged collagen and (ii) anti‐polypeptide antibodies, which do not associate with native collagen, but are strongly recognized by collagen fragments in naturally or artificially aged collagen, is a valuable tool in determining the extent of decay in works of art. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
Analogs of arginine vasopressin modified in the N‐terminal part of the molecule with a conformationally constrained cis‐peptide bond motif
Authors: Sobolewski Dariusz , Prahl Adam , Derdowska Izabela , Slaninová Jiřina , Kaczmarek Krzysztof , Zabrocki Janusz , Lammek Bernard
Published: December 2006

The present work is part of our studies aimed at clarifying the influence of steric constraints in the N‐terminal part of arginine vasopressin (AVP) and its analogs on the pharmacological activity of the resulting peptides. We describe the synthesis of eight new analogs of AVP or [3‐mercaptopropionic acid (Mpa)1]AVP (dAVP) substituted at positions 2 and 3 or 3 and 4 with two diastereomers of 4‐aminopyroglutamic acid. The steric constraints provided by this modification turned out, however, so strong that all the peptides were inactive in all of the bioassays (pressor, antidiuretic and uterotonic tests). Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
Raman study of β‐Sr0.33V2O5 micro‐crystals under high pressure
Authors: Kontos A. G. , Lampakis D. , Popović Z. V. , Raptis Y. S. , Liarokapis E. , Isobe M. , Ueda Y.
Published: December 2006

The phonon dynamics of the strontium vanadium oxide bronze (β‐Sr0.33V2O5) is studied using Raman spectroscopy at different temperature under high pressure up to 5.7 GPa. Interesting features of the spectra, such as the narrowing of some modes that harden under pressure (250–300 cm–1) or the softening of a low‐frequency mode, are presented and discussed. Our low temperature measurements confirm that under high hydrostatic pressure the charge ordered phase is suppressed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pressure effects on surfactant solubilized single‐wall carbon nanotubes
Authors: Freire P. T. C. , Lemos V. , Lima J. A. , Saraiva G. D. , Pizani P. S. , Nascimento R. O. , Ricardo N. M. P. S. , Mendes Filho J. , Souza Filho A. G.
Published: December 2006

Raman scattering investigations of surfactant solubilized SWCNTs under hydrostatic pressure were performed. The wave number dependence on pressure for the tangential bands was observed to be discontinuous at 2 GPa, with change of slope for higher pressures. This change coincides with the calculated critical pressure for collapse of the tubes. Therefore, it could be considered as indicative of deformation of the tube along the radial direction. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fertility and testicular fatty acid composition in the chicken as influenced by vitamin E and ethoxyquin
Authors: Tinsley I. J. , Arscott G. H. , Lowry R. R.
Published: December 2006

The fatty acid composition of testicular lipids has been determined and related to fertility data from groups of dubbed White Leghorn cockerels after a 50‐week feeding period on rations containing 10% safflower oil or coconut oil. Supplements of ethoxyquin ord‐α‐tocopherol acetate maintained fertility in birds raised on rations containing safflower oils. This response was associated with higher proportions of 22∶4 ω6 and lower proportions of 18∶2 ω6 in testicular lipids. Testes size was quite variable in the unsupplemented group with changes in fatty acid composition being more pronounced in the smaller testes. A multiple regression was calculated using data from those birds on the safflower oil ration. With a correlation ratio of 0.90 fertility was expressed as a function of testes size, semen concentration and the proportions of 18∶2 ω6, 20∶4 ω6 and 22∶4 ω6 in testicular lipids. Despite the low intake of linoleate significant levels of polyunsaturated fatty acids were maintained in testicular lipids of birds fed the coconut oil rations. The major changes in fatty acid composition of testicular lipids produced by this variable was a decrease in the proportion of 18∶2 ω6 and an increase in the proportion of 18∶1.
Eiution characteristics of fatty acid methyl esters on capillary columns
Authors: Nelson Gary J.
Published: December 2006

The elution characteristics of fatty acid methyl esters on support‐coated and open tubular capillary columns were investigated using reference standards and natural mixtures of fatty acid methyl esters. Over an extended range of fatty acid methyl esters chain lengths (C‐11–C‐26), the plot of the log of the adjusted retention time, t′R, vs. number of carbon atoms in the fatty acid chain was not linear, as has been previously assumed by many investigators. With support‐coated open tubular columns and with diethylene glycol succinate as the stationary phase, the relationship between the log of the retention time and carbon number was best approximated by a second‐order equation: log (t′R)x=α+β(CNx)+γ(CNx)2 where α, β, and γ are the virial coefficients of the equation. In addition, for the longer fatty acid methyl esters, the plots all tended to converge. Hence, for data from capillary columns, especially over a wide range of carbon numbers, all tentative indications based upon linear log plots and parallel lines for different homologous series of fatty acid isomers should be viewed with caution. A method is presented for identifying peaks from capillary columns; it uses quadratic equations and three reference fatty acid methyl ester standards for each homologous series being studied.
Cholanoic (bile) acids in hepatic and nonhepatic tissues of miniature swine
Authors: Dupont Jacqueline , Oh Suk‐Yon , O'Deen Louise A. , Geller Sigmund
Published: December 2006

Preliminary information is given indicating that all tissues of the miniature swine examined thus far contain cholanoic (bile) acids. Thin layer and gas chromatographic analyses suggest that the cholanoic acids are conjugated with glycine and taurine. The amounts appear to be substantial and should be assessed in regard to studies of cholesterol turnover.
Dietary fats and properties of endoplasmic reticulum: II. Dietary lipid induced changes in activities of drug metabolizing enzymes in liver and duodenum of rat
Authors: Hietanen E. , Laitinen M. , Vainio H. , Hänninen O.
Published: December 2006

Rats were fed cholesterol, cacao butter, or olive oil diets to determine the effect of dietary lipids on the rate of drug biotransformation in the liver and duodenum. The cholesterol rich diet maintained the hepatic aryl hydrocarbon hydroxylase activity at the same level as did the standard diet. Rats fed olive oil and cacao butter diets showed lower hepatic aryl hydrocarbon hydrorylase activity. The p‐nitroanisole 0‐demethylase activity was doubled in hepatic microsomes of rats fed the high cholesterol diet when compared to rats fed the standard diet. The hepatic uridine diphosphate glucoronosyltransferase activity showed different patterns depending on the in vitro treatment of the microsomal membranes. If the enzyme activity was assayed from the native, untreated microsomes, an increase in the measurable uridine diphosphate glucuronosyl transferase activity was found in rats having cholesterol rich diet. After the in vitro activation of membrane‐bound uridine diphosphate glucuronosyltransferase by trypsin, the increase in measurable activity was 10 fold in the group fed the standard diet, 6 fold in group fed cholesterol, 4 fold in group fed cacao butter, and 3 fold in group fed olive oil. Trypsin digestion of microsomes increased the measurable uridine diphosphate glucuronosyltransferase activity less in rats fed diets rich in neutral fats than those fed the standard diet. In the duodenal mucosa, lipid diets decreased the activities of drug hydroxylation and glucuronidation.
Taxus baccata seed oil: A new source ofcis‐5,cis‐9‐octadecadienoic acid
Authors: Madrigal R. V. , Smith C. R.
Published: December 2006

Methyl esters prepared from the seed oil of the coniferTaxus baccata L. were found by gas liquid chromatography to contain 12% of a component which, when isolated by preparative thin layer chromatography and characterized by mass spectrometry, ozonolysis and nuclear magnetic resonance, was identified ascis‐5,cis‐9‐octadecadienoic acid.
Isolation of human serum low‐density lipoproteins with the aid of an immune‐specific adsorber
Authors: Kostner Gerhard , Holasek Anton
Published: December 2006

Human serum lipoproteins containing B‐protein have been isolated using an immunoadsorber. Bromoacetyl cellulose was combined with pure antibodies to low density lipoprotein (LDL) and an immunoadsorber of high capacity was obtained. With 1 g of this immunoadsorber all LDL and very low density lipoprotein (VLDL) from 30 ml pooled human serum were adsorbed and then eluted with glycine‐HCl buffer pH 3.2 at 0 C. The isolated lipoproteins were investigated by electrophoresis, immunodiffusion and ultracentrifugation, and found to be identical to LDL+VLDL isolated by ultracentrifugation.
Variation in lipase activities during germination (in dark) of γ‐irradiated castor‐seeds
Authors: Thanki R. J. , Patel K. C. , Patel R. D.
Published: December 2006

A special variety ofR. communis selected for the present investigation, indicated two types of lipases. One of these, is active at pH 4.5 and another at pH 6.8. The acid lipase was maximum in dry seeds. The control and the irradiated seeds when germinated in dark showed a decrease in acid lipase. The decrease in acid lipase was dependent on the period of germination and the applied irradiation dose. The presence of a de novo synthesis of another activity measured at pH 6.8 was found after 24 hr of germination of the control as well as the irradiated seeds. The new activity termed as a neutral lipase showed a gradual increase with the period of germination. Irradiation played a characteristic role in the production of this activity.
Corticoid release and gluconeogenesis following triglyceride ingestion in the rat
Authors: Lenz Paul H. , Wien George H. , Fleischman Alan I.
Published: December 2006

Following a 5.0 ml triglyceride (cottonseed oil) gavage, there was a 60% elevation in the blood glucose concentration by the seventh hour in naturally occurring hypertriglyceridemic rats of the Long Evans strain. Glycogenolysis from liver or gastrocnemius muscle glycogen did not seem to be the source of this glucose. A significant elevation in the plasma total amino acid concentration concomitant with a peak in the blood urea nitrogen concentration by the fifth hour after gavage implicated gluconeogenesis. A prolonged plasma total corticoid elevation from hours 1 1/2 through 3 post‐ingestion, which did not occur in non‐fed or mineral oil‐fed cohorts, supported gluconeogenesis. The serum total protein concentration rose significantly and progressively to a peak by the eighth hour due to an elevation in the albumin concentration. These elevations in serum proteins appeared to support glucocorticoid mediated gluconeogenesis. Adrenalectomy appeared to negate triglyceride‐induced elevation in serum free amino acids, urea nitrogen, total protein and albumin.
Polymorphism of glyceryl ethers and ether esters
Authors: Lutton E. S. , Stewart C. B.
Published: December 2006

Phase behavior has been studied by thermal and diffraction methods for 1‐and 2‐palmityl and stearyl ethers of glycerol and for 14 trialkyl glyceryl ethers, dialkyl monoacyl glyceryl ethers and monoalkyl diacyl glyceryl ethers, all of which were saturated trichain substituted glycerol compounds containing one or more of the following chains: palmityl (Py), palmitoyl (P), stearyl (Sy) and stearoyl (S). The monoalkyl glyceryl ethers resemble monoglycerides in crystallization behavior but with significant differences. Isomeric 1‐ and 2‐ethers are very close in melting point. The 1‐ethers show, besides a stable form, two other forms which transform reversibly to each other. The 2‐ethers are polymorphic but with only one clearly established melting level. All trichain compounds were polymorphic also, most being dimorphic, each exhibiting a metastable α form, typically more stable than that of related triglycerides. Forms other than α were labeled I, II, etc., in order of decreasing melting point and were typically obtained from solvent. Polymorphic behavior showed some rather large departures from that of related triglycerides and appeared generally more sensitive to impurities. The two triethers, PyPyPy and SySySy were dimorphic each with a stable form much resembling metastable α in diffraction pattern, hence presumed to be of a new (more dense) hexagonal type of cross sectional structure. Three dialkyl monoacyl compounds PyPyP, SySyS and SyPyS and also three monoalkyl diacyl compounds PPyP, SSyS and SPyS were dimorphic, with Form I a stable, nontilted, somewhat β′‐like form. PySyS and PSyP, which were trimorphic, showed such a β′‐like form as a Form II, i.e., a second highest melting point. The stable phase of four compounds, namely PyPP, SySS, PySyS (all trimorphic) and dimorphic PySS (and possibly that of SyPP) could be called a β phase. Presence of an alkyl group on the 2 position of glycerol, in all but the PySyS, prevented β structure. PSyP and SyPP exhibited triple chain length structures, not encountered in saturated mixed triglycerides with less than four carbons difference in the acyl chains. SyPP was exceptional in showing four forms.
Exceptional occurrence of odd‐chain fatty acids in smelt (Osmerus mordax) from Jeddore Harbour, Nova Scotia
Authors: Addison R. F. , Ackman R. G.
Published: December 2006

The fatty acid composition of smelt,Osmerus mordax, from several areas in Eastern Canada is reported. Smelt from Jeddore Harbour, N.S., were unusual in having up to 10% of C15, C17 and C19 acids. These acids were similar in structure to odd‐chain acids occurring in other marine lipids, notably mullet, and were distributed among all body and gonad lipids. Possible reasons for their occurrence are discussed.
Reactions of fatty aldehydes with fatty alcohols: Formation of acetals, hemiacetals and alk‐1‐enyl alkyl ethers
Authors: Mahadevan V.
Published: December 2006

A convenient method for the synthesis of acetals of fatty aldehydes and fatty alcohols by transacetatlation between fatty aldehyde dimethyl acetals and fatty alcohols is described. The acetals undergo decomposition to the alk‐1‐enyl alkyl ethers during GLC. Equimolar mixtures of fatty aldehydes and fatty alcohols show hemiacetal structure as evidenced by IR spectra in KBr discs but are dissociated completely into their components in solution and during TLC. They do not undergo dehydration and conversion to alk‐1‐enyl alkyl ethers during GLC under conditions of dealcoholization of acetals but are dissociated into aldehydes and alcohols.
Glycodihydrofusidate: Biliary excretion and its effect on biliary secretion of the rat
Authors: Montet J. C. , Montet A. M. , Gerolami A. , Amic J. , Hauton J. C.
Published: December 2006

Glycodihydrofusidate, which has the same detergent properties as bile salts, is excreted almost exclusively by the bile duct after intravenous injection in the rat. As with bile salts, it leads to a significant (P≤0.05) increase in excretion of lecithins and cholesterol (0.15 μmol lecithin and 0.026 μmol cholesterol per 1 μmol of glycodihydrofusidate excreted). In addition, this drug simultaneously inhibits excretion of both endogenous bile salts and bile pigments.
Identification of plant sterols in plasma and red blood cells of man and experimental animals
Authors: Kuksis A. , Marai L. , Myher J. J. , Geher K.
Published: December 2006

Direct gas liquid chromatography (GLC) of total plasma lipids showed small peaks (0.5–1.5% of total free sterol area) corresponding to free C28 and C29 sterols in ca. 50% of some 3,000 normal subjects and patients with hyperlipemia. Comparable proportions of similar peaks were present in the sterol fraction isolated from the red blood cells of many of these subjects. The maximum levels of these components in the plasma and red blood cells of domestic and laboratory animals were up to 10 times higher than those seen in man. Detailed gas chromatography/mass spectrometry analyses of the plasma lipids from a much more limited number of subjects and animals showed that the GLC peaks corresponding to the free C28 and C29 sterols were largely due to the plant sterols campesterol, stigmasterol, and β‐sitosterol. In all instances, variable amounts (0.05–0.2% of the total free sterol area) of 7‐dehydrocholesterol, desmosterol, lanosterol, and cholesterol α‐oxide were also detected. While the total content and composition of the plasma plant sterols appeared to vary greatly among the subjects, it never exceeded 2% of total sterol in the normal subjects and patients examined. There was no evidence for a significant increase in the plant sterol content of the plasma of patients with hypercholesterolemia or hypertriglyceridemia.
Age‐related changes in the lipid metabolism of Fisher 344 rats
Authors: Story Jon A. , Tepper Shirley A. , Kritchevsky David
Published: December 2006

Lipid metabolism of male Fisher 344 rats aged 2–24 months was studied. Serum and liver cholesterol levels did not display the age‐related gradual increase seen in other rat strains. An increase in the serum plus liver cholesterol pool from 2 to 6 months was followed by a plateau through 18 months and then another increase at 24 months of age. The triglyceride pool increased from 2 to 6 months and then remained unchanged through 24 months of age. Cholesterol synthesis from acetate decreased 50% between 2 and 9 months and fell only slightly through 24 months of age. Assay of 3‐hydroxy‐3‐methyl glutaryl Coenzyme A (HMG‐CoA) reductase showed a similar pattern but did not decrease further after 9 months of age. Cholesterol 7α hydroxylase activity was not significantly altered by age. These age‐ and strain‐related differences present an opportunity for a comparative study of the aging process using the parameters of lipid metabolism as indicators.
Effect of ethanol ingestion on choline phosphotransferase and phosphatidyl ethanolamine methyltransferase activities in liver microsomes
Authors: Uthus Erico O. , Skurdal David N. , Cornatzer W. E.
Published: December 2006

The effect of ethanol ingestion on choline phosphotransferase and phosphatidyl ethanolamine methyltransferase activities, the two enzymes involved in phosphatidyl choline biosynthesis in liver microsomes, has been investigated. Female rats were fed a 5% ethanol‐liquid diet containing amino acids, minerals, vitamins, with and without choline, for 2, 6, and 10 weeks. Control animals were pair‐fed the same isocaloric diet with 5% sucrose with and without choline. Ethanol administration with or without dietary choline stimulated significantly (P<0.001) the specific activities of phosphatidyl ethanolamine methyltransferase in liver microsomes in the animals fed 5% ethanol for 2, 6, and 10 weeks, when compared to those control animals pairfed the isocaloric diet with or without choline. Ethanol administration with or without dietary choline for 2 weeks stimulated significantly (P<0.02) the specific activities of choline phosphotransferase. The specific activities of phosphatidyl ethanolamine methyltransferase continued to increase in the liver microsomes from the animals in which dietary choline was omitted for 2, 6, and 10 weeks in the sucrose controls and alcohol‐fed animals. Ethanol administration stimulates significantly (P<0.001) the phosphatidyl ethanolamine methyltransferase specific activities in liver microsomes of animals fed the liquid diet with dietary omission of choline and methionine for 2 weeks.