bluuebunny/crossref_metadata_2025 huggingface dataset:
Oriented crystallization of crosslinked cis‐1,4‐polybutadiene rubber
Authors: Saijo Kenji , Zhu Yu‐Ping , Hashimoto Takeji , Wasiak Andrzej , Brzostowski Norbert
Published: April 2007

Crosslinked cis‐1,4‐polybutadiene (PB) rubber is known to undergo crystallization during mechanical deformation. This article presents small‐angle X‐ray scattering (SAXS), wide‐angle X‐ray scattering (WAXS), and stress‐relaxation studies of the structural development in crosslinked PB samples crystallized under various orientation regimes. The studies are concerned with isothermal crystallization at various temperatures (10 to −50°C) and at constant elongation ratios (1–4.5) and hence with the effects of weak‐to‐intermediate and high orientations on oriented crystallization versus the behavior of unoriented specimens. The results for weak‐to‐intermediate orientations indicate a decrease in the long spacing during crystallization, which is accompanied by an almost constant lamellar thickness as well as a significant time lag between the development of crystallinity revealed by WAXS and SAXS intensity measurements. The SAXS integral intensity shows an overshoot; that is, the intensity reaches a maximum after some crystallization time and then decreases. Stress measured during crystallization with constant elongation ratios shows decay, which depends on the isothermal crystallization temperature and elongation ratio. Although the crystallization in the weak‐to‐intermediate orientations is interpreted on the basis of nucleation growth, the crystallization under high orientations is best interpreted on the basis of spinodal crystallization. The most pronounced feature of structural formation during crystallization under high orientations is an almost constant long period from nearly the beginning of the crystallization, even in a timescale in which other physical quantities such as the WAXS crystallinity, SAXS integral intensity, and stress still change with time, suggesting spinodal‐like crystallization, orientation‐induced instability of molten network chains and their ordering, which involves spinodal‐decomposition‐like segregation of noncrystallizable parts (crosslinked points) and crystallizable parts (linear chains between the crosslinks) of network chains, and subsequent crystallization of crystallizable chains and pinning of the ordering process induced by crystallization. To the best of our knowledge, this work reports for the first time spinodal‐like crystallization on oriented crosslinked polymer melts. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 137–157, 2007
Poly[(diphenylsilanediyl)ethynediyl]: Structure and optical and electroluminescent properties
Authors: Nešpůrek Stanislav , Toman Petr , Fujii Akihiko , Yoshino Katsumi
Published: April 2007

Poly[(diphenylsilanediyl)ethynediyl] with a band‐gap energy of 5.2 eV is a wide‐band‐gap material with a photoluminescence maximum at a wavelength of 354 nm. It is suitable for the fabrication of ultraviolet electroluminescence diodes. The electroluminescence spectrum consists of a strong peak at 361 nm and a tail up to 570 nm. The external quantum emission efficiency at the main maximum, calculated in terms of emitted photons per transported electronic charge, is 0.01% (no sample optimization has been carried out). The electric characteristics are controlled by contact‐limited currents and double injection. The geometry of the neutral oligo[(diphenylsilanediyl)ethynediyl] molecule and its infrared spectra and the changes in the geometries and charge distributions during the formation of the positive and negative ions have been calculated by quantum chemical methods. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 208–214, 2007
Features of fluorescence spectra of polyethylene 2,6‐naphthalate films
Authors: Ouchi I. , Nakai I. , Ono M. , Kimura S.
Published: April 2007

The characteristics of the fluorescence spectra of polyethylene 2,6‐naphthalate (PEN) films were compared with those of poly(ethylene terephthalate) (PET). The fluorescence spectra of PEN films were found, by photoselection, to consist of two components, one peaking at 425 nm and the other at 445 nm, with their emission transition moments perpendicular to each other. The integrated excitation spectra of the PEN films were much more intense than those of PET. After the resolution of the integrated excitation spectra of PEN, most, but not all, of their component peaks corresponded to those of the absorption spectra. On the basis of this fact together with previous data on photodegradation, the spectral component peaking at 445 nm originated, at least partly, from traces of photochemical products generated by exposure during the measurements. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 114–121, 2007
Synthesis and properties of self‐crosslinkable thermoplastic polyurethanes
Authors: Lapprand A. , Méchin F. , Pascault J.‐P.
Published: April 2007

The chemical modification of a thermoplastic polyurethane (TPU) has been realized by the grafting of polyisocyanates onto urethane groups through allophanate bonds to prepare self‐crosslinkable but still thermoplastic materials. Because of the lateral isocyanate groups, the resulting polymer can be easily crosslinked by the ambient moisture. However, because of the highly viscous character of the TPU even at a high temperature, this chemical reaction must be performed with a twin‐screw extruder above 190°C. The ability of linear, segmented TPUs to undergo physical (micro)structuration that strongly depends on their thermal history has been widely described in the literature, and these transformations usually occur in the same temperature range as that used for performing our chemical reactions. Moreover, the thermally reversible character of urethane and allophanate bonds above ∼ 170°C is also well‐known. Therefore, the precise characterization of the thermomechanical properties of the initial and modified materials is quite delicate because microstructural phenomena and chemical rearrangements can compete and always have to be considered simultaneously. Considering these restrictions, we have nevertheless demonstrated that the structural transformation is faster than crosslinking for a partially crosslinked TPU, but microphase separation is no longer possible for a TPU with a gel fraction higher than 50%. The chemical crosslinks of the modified TPU are reversible, but they still allow an important increase in the thermomechanical properties at a high temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 99–113, 2007
Composites of poly(L‐lactide) with hemp fibers: Morphology and thermal and mechanical properties
Authors: Masirek Robert , Kulinski Zbigniew , Chionna Donatella , Piorkowska Ewa , Pracella Mariano
Published: April 2007

Composites of poly(L‐lactide) (PLA) with hemp fibers (Cannabis sativa), prepared by batch mixing and plasticized with poly(ethylene glycol) (PEG; weight‐average molecular weight = 600 g/mol), were examined by polarized optical microscopy, scanning electron microscopy, wide‐angle X‐ray scattering, differential scanning calorimetry, thermogravimetric analysis, and mechanical tests. The properties of both fully amorphous and semicrystalline samples of PLA/hemp and PLA–PEG/hemp composites were analyzed as a function of the fiber amount. The cold‐crystallization kinetics of PLA in amorphous composites were investigated under isothermal conditions within the range of 70–130°C. For PLA/hemp samples, the bulk crystallization rate displayed a maximum near 110°C, whereas for plasticized samples, a higher and almost constant crystallization rate was observed over the entire temperature range, independently of the hemp amount. The kinetics were then analyzed on the basis of the Avrami model. The effect of fibers on the growth morphology of PLA spherulites, as well as the influence of the plasticizer on the melting behavior of PLA crystals and their reorganization during heating, was also examined. The thermogravimetric analysis of the composites, carried out in both nitrogen and air, showed that the degradation process of fiber‐filled systems started earlier than that of plain PLA, independently of the presence of the plasticizer. Mechanical tests showed that the modulus of elasticity of the composites markedly increased with the hemp content, reaching 5.2 GPa in the case of crystallized PLA reinforced with 20 wt % hemp, whereas the elongation and stress at break decreased with an increasing amount of fiber for all examined systems. Plasticization with PEG did not improve the tensile properties of the composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 255–268, 2007
Modification of rubber by iodoform
Authors: Bieliński Dariusz M. , Ślusarski Ludomir , Głąb Piotr
Published: April 2007

The activity of iodoform (CHI3) toward unsaturated rubbers was examined. Special attention was devoted to cis‐1,4‐(poly)isoprene (IR). The thermal decomposition of CHI3 was studied by ion mass spectroscopy, and the obtained data were used for the identification of pyrolysis products of CHI3 vulcanizates by pyrolytic gas chromatography. The kinetics of the chemical crosslinking of rubber were studied with a cure meter. The changes observed in the chemical structure of rubber were explained on the basis of 13CNMR and Fourier transform infrared spectroscopy, differential scanning calorimetry, equilibrium swelling, and chemical microanalysis data. Apart from crosslinking, a simultaneous modification of the rubber macromolecules took place, specifically the cis–trans isomerization of IR. This resulted in a significant increase in the rubber hardness, especially after a postheat treatment accompanied by oxidation. CHI3–IR vulcanizates behaved like thermoplastics because of the presence of a trans‐1,4 phase, as confirmed by dynamic mechanical thermal analysis. The structure of the macromolecules treated with CHI3 and its effect on the physical properties of the material were compared with those of peroxide–IR vulcanizates. The influence of the modification on the surface energy, bacteriostaticity, and mechanical properties of the vulcanizates was examined. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 177–189, 2007
Studies of the molecular dynamics in polyurethane networks with hyperbranched crosslinkers of different coordination numbers
Authors: Czech Przemyslaw , Okrasa Lidia , Ulanski Jacek , Boiteux Gisele , Mechin Francoise , Cassagnau Philippe
Published: April 2007

Several new polyurethane networks based on hyperbranched polyesters (trade name Boltorn) were synthesized to investigate the influence of the hyperbranched crosslinking agent on the molecular dynamics of the linear segments containing urethane groups. For comparison, linear polyurethanes as well as polyurethanes crosslinked with the classical crosslinker trimethylolpropane were prepared. Broadband dielectric spectroscopy, dynamic mechanical analysis, and differential scanning calorimetry yielded consistent results concerning the molecular relaxation processes; however, dielectric spectroscopy appeared to be more sensitive concerning the secondary relaxation processes. In the temperature range up to 150°C, the molecular relaxations were very similar in all the investigated samples, despite considerable structural differences. The weak influence of the crosslinking on the molecular properties could be explained by the existence of hydrogen bonds forming a physical network, which was very dense in this temperature range in comparison with the chemical crosslinks and therefore dominated the molecular mobility in all the investigated systems. This hypothesis was confirmed by rheological measurements performed at temperatures above 150°C, when the hydrogen bonds should be thermally destroyed. At these temperatures, the effect of crosslinking was manifested by a strong shift of the flowing point: in the linear polyurethanes, this point occurred at much higher frequencies (and lower temperatures) than in the crosslinked analogues. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 89–98, 2007
Effect of crosslinking on polymer electrolytes based on cellulose
Authors: Chelmecki Marcin , Meyer Wolfgang H. , Wegner Gerhard
Published: April 2007

Polymer electrolytes based on biogenic and commercially available substrates have been crosslinked thermally to improve their mechanical properties with only negligible effects on their conductivity. The new materials consist of oligo(ethylene oxide) side chains grafted via ether linkages to a cellulose backbone [poly(ethylene oxide)–2‐hydroxypropylcellulose (PEO–HPC)]. PEO–HPC with a degree of side‐chain substitution up to 3.0, as determined by NMR, has been blended with lithium bis(trifluoromethylsulfone)imide in molar ratios of 0.02 ≤ [Li]/[O] ≤ 0.2. The effect of the salt concentration on the thermal behavior and ionic conductivity has been investigated by impedance spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The uncrosslinked materials are viscous liquids. The PEO–HPC/lithium salt blends have been thermally crosslinked with the application of urethane chemistry. The crosslinking reactions have been monitored by dynamic mechanical analysis. Crosslinking renders the liquid materials into mechanically stable films with a storage modulus of 105 Pa at 100°C. Surprisingly, their conductivities remain rather unaffected and reach at best 2.5 × 10−4 S/cm. The applicability of the PEO–HPC/lithium salt blends as separators in lithium‐ion batteries has been demonstrated by the construction of a storage cell that is rechargeable. A freshly constructed cell reveals a voltage of about 3.2 V and can be recharged with a constant direct‐current voltage up to the open circuit voltage of 3.65. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 25–29, 2007
Preparation and dynamic mechanical properties of polyurethane‐modified epoxy composites filled with functionalized fly ash particulates
Authors: Wu Gaohui , Gu Jian , Zhao Xiao
Published: April 2007

Fly ash (FA) is a porous ceramic, which has proved to have some favorable functions. In this article, we have prepared a series of fly ash filled composites, where the polyurethane‐(PU) modified epoxy (EP) was acted as the matrix. With the purpose of characterizing the effect of the content of PU in the matrices and the surface‐treatment (ST) of fly ash particulates on the dynamic mechanical properties of composites, Fourier transform infrared spectral analysis (FTIR), microstructure observation, impact property test as well as dynamic mechanical analysis (DMA) were systematically investigated. With FTIR test, it can be found that the chemical reactions occur, and new chemical structures are formed between EP and PU, and the functionalized groups existing on the surface of fly ash particulates can also be detected. In fractographs observation of composites, it can be seen that the silane coupling agent improves the interfacial bonding conditions between fly ash particulates and the matrix. Impact property test result reveals that PU improves the toughness of EP. Dynamic mechanical analysis of the composites is carried out from −40 to 150°C using a tension‐compression mode. Results show that the composites, whose matrices are with 10 and 20 wt % PU, may possess better dynamic mechanical properties as compared with the other composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Melt‐electrospinning of poly(ethylene terephthalate) and polyalirate
Authors: Ogata Nobuo , Shimada Naoki , Yamaguchi Shinji , Nakane Koji , Ogihara Takashi
Published: April 2007

Rodlike polymer samples were made from three kinds of poly(ethylene terephthalate) (PET) pellets with different intrinsic viscosities (IV), and from polyalirate (Vectra) pellets. PET and Vectra fibers were produced using a melt‐electrospinning system equipped with a CO2‐laser melting device from these rodlike samples. The effects of IV value and laser output power on the fiber diameter of PET were investigated. Furthermore, the effect of the laser output power on the fiber diameter of Vectra was investigated. The crystal orientation of these produced fibers was also investigated by X‐ray photographs. The following conclusions were reached: (i) the diameter of PET fiber decreases with increasing laser output power; (ii) the minimum average diameter of PET fibers is scarcely influenced by the value of IV; (iii) the electrospun PET fibers show isotropic crystal orientation; (iv) fibers having an average fiber diameter smaller than 1 μm cannot be obtained from PET and Vectra using the system developed; and (v) preferred liquid crystal orientation can be seen in electrospun Vectra fibers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Bioinspired Nanodevice Based on the Folic Acid/Titanium Dioxide System
Authors: Gawęda Sylwia , Stochel Grażyna , Szaciłowski Konrad
Published: April 2007

A new bioinspired nanomaterial has been obtained by chemisorption of folic acid onto nanocrystalline titanium dioxide. The organic chromophore is linked with the semiconductor surface via the glutamate chain and anchored with the carboxylate group. The geometry and electronic structure of the chromophore was studied in detail with DFT. Photoelectrochemical studies revealed photosensitization of the new material towards visible light. The photoelectrodes composed of the folic acid/titanium dioxide hybrid material generated photocurrent over a 300–600‐nm window. Moreover, the direction of the photocurrent could be changed from anodic to cathodic and vice versa by application of the appropriate photoelectrode potential. Photoelectrochemical and spectroscopic studies allowed the elucidation of the mechanism of photocurrent switching. Photoelectrodes composed of folate‐modified titanium dioxide may serve as a simple model of optoelectronic switches and may constitute the basis for molecular photoelectronic devices.
Nonstereogenic α‐aminoisobutyryl‐glycyl dipeptidyl unit nucleates type I′ β‐turn in linear peptides in aqueous solution
Authors: Masterson Larry R. , Etienne Marcus A. , Porcelli Fernando , Barany George , Hammer Robert P. , Veglia Gianluigi
Published: April 2007

The use of α,α‐disubstituted amino acids represents a valuable strategy to exercise conformational control in peptides. Incorporation of the nonstereogenic α‐aminoisobutyryl‐glycyl (Aib‐Gly) dipeptidyl sequence into i + 1 and i + 2 positions of an acyclic peptide sequence, originally designed and investigated by Gellman and coworkers, [H‐Arg‐Tyr‐Val‐Glu‐Val‐Yyy‐Xxx‐Orn‐Lys‐Ile‐Leu‐Gln‐NH2] nucleates a stable [2:4] left‐handed type I′ β‐turn in water. NMR spectra show that this newly designed β‐hairpin does not aggregate in water up to a concentration of ∼1 mM, and that its backbone conformation is superimposable on corresponding hairpins containing the DPro‐Gly (literature) and Aib‐DAla (this work) sequences. The Aib‐Gly turn‐inducer sequence eliminates complications because of cis–trans isomerization of Zzz‐Pro bonds, and constitutes an attractive alternative to the proteogenic Asn‐Gly and nonproteogenic DPro‐Gly motifs previously suggested as turn‐inducer sequences. These design principles could be exploited to prepare water‐soluble β‐hairpin peptides with robust structures and novel function. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 746–753, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Targeting protein–protein interactions: Lessons from p53/MDM2
Authors: Murray Justin K. , Gellman Samuel H.
Published: April 2007

The tremendous challenge of inhibiting therapeutically important protein–protein interactions has created the opportunity to extend traditional medicinal chemistry to a new class of targets and to explore nontraditional strategies. Here we review a widely studied system, the interaction between tumor suppressor p53 and its natural antagonist MDM2, for which both traditional and nontraditional approaches have been reported. This system has been a testing ground for novel proteomimetic scaffold‐based strategies, i.e., for attempts to mimic the recognition surface displayed by a folded protein with unnatural oligomers. Retroinverso peptides, peptoids, terphenyls, β‐hairpins, p‐oligobenzamides, β‐peptides, and miniproteins have all been explored as inhibitors of the p53/MDM2 interaction, and we focus on these oligomer‐based efforts. Traditional approaches have been successful as well, and we briefly review small molecule inhibitors along with other strategies for reactivation of the p53 pathway, for comparison with oligomer‐ based approaches. We close with comments on an emerging dichotomy among protein–protein interaction targets. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 657–686, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Functional genome‐wide analysis of antibody producing NS0 cell line cultivated at different temperatures
Authors: Swiderek Halina , Al‐Rubeai Mohamed
Published: April 2007

Lowering culture temperature has been reported as a significant factor in the improvement of mammalian cell productivity. To determine the physiological changes which take place at different temperature cultivations, an NS0 cell line producing human‐mouse chimeric antibody was cultured at 22, 34 and 37°C. Various cellular parameters such as viability, productivity, metabolism, apoptosis and cell cycle were studied and notable changes were shown to be accompanied by changes in metabolic rates. Reduction of the temperature to 22°C resulted in a decrease in the growth rate, inhibition of antibody production, arrest of cell cycle in G2 phase and delay in apoptosis. A slight increase in antibody production was observed at 34°C due to the increase of growth rate and prolonged stationary phase. To better understand and explore the mechanisms underpinning these biological alterations and to identify the genes involved in the genetic reprogramming, genome‐wide analyses were performed using GeneChip Mouse Genome arrays. The examination of differential gene expression induced by temperature reduction demonstrated a specific pattern of gene expression in NS0 cells in response to temperature stress. The effect of temperature on transcription induced changes within a wide range of genes involved in metabolic and signalling pathways. Most deregulated genes involved in essential metabolic pathways (i.e. glycolysis/gluconeogenesis, pentose phosphate pathway and inositol metabolism) were repressed in cells cultured at 22°C. By combining gene expression and physiological changes at different temperatures it was possible to provide greater understanding of cell response to hypothermic conditions. Biotechnol. Bioeng. 2007;98: 616–630. © 2007 Wiley Periodicals, Inc.
Structure and shear strength of microbial biofilms as determined with confocal laser scanning microscopy and fluid dynamic gauging using a novel rotating disc biofilm reactor
Authors: Möhle Roland B. , Langemann Timo , Haesner Marian , Augustin Wolfgang , Scholl Stephan , Neu Thomas R. , Hempel Dietmar C. , Horn Harald
Published: April 2007

The cohesive strength of microbial biofilms cultivated on a rotating disc has been measured using fluid dynamic gauging (FDG). The thickness of heterotrophic mixed culture biofilms was found to depend on substrate concentration and shear force at the biofilm surface during the cultivation. For high substrate concentrations and low shear forces the biofilm thickness increased to several 100 µm within 7 days. Low substrate concentration and higher shear forces yielded thin biofilms of about 100 µm thickness. Independent from cultivation conditions and thickness of the biofilms their cohesive strength ranged between 6.0 and 7.7 N m−2. The ratio between cohesive strength measured with FDG and shear forces applied during biofilm cultivation have ranged from 200 to 1,100. Higher concentrations of iron in the cultivation media has a positive effect on the stability of the biofilms cultivated. By using the CLSM technique a stable base biofilm with a high amount of stained EPS glycoconjugates could be visualized after gauging. The thickness of the base biofilm was about 100 µm for all biofilms cultivated and was not removable under the applied shear conditions used during FDG. Biotechnol. Bioeng. 2007;98: 747–755. © 2007 Wiley Periodicals, Inc.
Optimal fed‐batch cultivation when mass transfer becomes limiting
Authors: Villadsen John , Patil Kiran R.
Published: April 2007

In the design of an aerobic fed‐batch process to produce, for example, a pharmaceutical protein, the volumetric production rate will eventually become limited by mass transfer when the biomass concentration exceeds a certain upper limit x*. It appears to be common practice to switch from exponential feed of substrate to a constant feed rate when x* is reached. This is done to avoid oxygen starvation with a potential risk of undesired stress responses. But with a constant feed rate the carbon source (glucose) concentration may decrease to a low level with a resulting loss of viability and an undesired production of endotoxins. It is shown that an exponential feeding strategy may be continued, but with a smaller exponent than the one used before oxygen limitation occurs. This will diminish the potential detrimental effects on the culture due to low glucose concentration, and the total time to reach a given final biomass concentration will be reduced. Biotechnol. Bioeng. 2007;98: 706–710. © 2007 Wiley Periodicals, Inc.
Hydrogen sulfide production from elemental sulfur by Desulfovibrio desulfuricans in an anaerobic bioreactor
Authors: Escobar Claudio , Bravo Loreto , Hernández José , Herrera Leandro
Published: April 2007

Feasibility of elemental sulfur reduction by Desulfovibrio desulfuricans in anaerobic conditions in a stirred reactor was studied. Hydrogen was used as energy source, whereas the carbonated species were bicarbonate and yeast extract. Attention was paid to reactor engineering aspects, biofilm formation on the sulfur surface, hydrogen sulfide formation rate and kinetics limitations of the sulfur reduction. D. desulfuricans formed stable biofilms on the sulfur surface. It was found that active sulfur surface availability limits the reaction rate. The reaction rate was first order with respect to sulfur and hydrogen velocity had no effect in the reaction rate for the range 8.2 × 10−2 to 4.1 × 10−1 Nm3 m−2 min−1. At a superficial gas velocity (uG) = 3.1 × 10−2 Nm3 m−2 min−1, H2S(g) production rate decreased due to a deficient H2S stripping. A maximum H2S(g) production rate of 2.1 g H2S L−1 d−1 was achieved during 5 days with an initial sulfur density of 4.7% (w/v). Biotechnol. Bioeng. 2007;98:569–577. © 2007 Wiley Periodicals, Inc.
Reproducible coronary plaque quantification by multislice computed tomography
Authors: Bruining Nico , Roelandt Jos R.T.C. , Palumbo Alessandro , Grutta Ludovico La , Cademartiri Filippo , de Feijter Pim J. , Mollet Nico , van Domburg Ron T. , Serruys P.W. , Hamers Ronald
Published: April 2007

Background: The aim of this study was to investigate reproducibility and accuracy of computer‐assisted coronary plaque measurements by multislice computed tomography coronary angiography (QMSCT‐CA). Methods and Results: Forty‐eight patients undergoing MSCT‐CA and coronary arteriography for symptomatic coronary artery disease and quantitative intravascular ultrasound (IVUS, QCU) were examined. Two investigators performed the QMSCT‐CA twice and a third investigator performed the QCU, all blinded for each other's results. There was no difference found for the matched region of interest (ROI) lengths (QCU 29.4 ± 13 mm vs. QMSCT‐CA 29.6 ± 13 mm, P = 0.6; total length = 1,400 mm). The comparison of volumetric measurements showed (lumen QCU 267 ± 139 mm3 vs. mean QMSCT‐CA 177 ± 91 mm3, P << 0.001; vessel 454 ± 194 mm3 vs. 398 ± 187 mm3, P << 0.001; and plaque 189 ± 93 mm3 vs. 222 ± 121 mm3; investigator 1, P = 0.02; and investigator 2, P = 0.07) significant differences. Automated lumen detection was also applied for QMSCT‐CA (218 ± 112 mm3, P << 0.001 vs. QCU). The interinvestigator variability measurements for QMSCT‐CA showed no significant differences. Conclusion: QMSCT‐CA systematically underestimates absolute coronary lumen‐ and vessel dimensions when compared with QCU. However, repeated measurements of coronary plaque by QMSCT‐CA showed no statistically significant differences, although, the outcome showed a scattered result. Automated lumen detection for QMSCT‐CA showed improved results when compared with those of human investigators. © 2007 Wiley‐Liss, Inc.
Percutaneous coronary artery fistula closurein adults: Technical and procedural aspects
Authors: Collins Nicholas , Mehta Rohit , Benson Lee , Horlick Eric
Published: April 2007

Background:

Coronary artery fistulae (CAF) are an uncommon congenital anomaly characterized by an abnormal connection between the coronary arteries and cardiac chambers or vessels without traversing the usual capillary network. CAF are associated with a number of well‐described symptomatic sequelae, which may necessitate treatment. With a tendency for symptoms to develop over time, symptomatic CAF may present for the first time in adulthood, with limited data existing on the technical aspects related to transcatheter fistula closure in adults.

Methods:

We describe our experience in percutaneous closure of CAF in an exclusively adult population, with an emphasis on the various procedural features of device closure in this patient group.

Results:

Attempted transcatheter CAF closure was performed in 14 patients between 1990 and 2006. Procedural success was achieved in 11 patients, with vessel tortuosity and lumen caliber important limitations in occlusion device delivery. Procedural complications included vessel dissection and device embolization.

Conclusion:

Transcatheter occlusion is a safe and effective method of therapy for symptomatic adults with CAF. © 2007 Wiley‐Liss, Inc.
The past, present, and future of chemometrics worldwide: some etymological, linguistic, and bibliometric investigations
Authors: Kiralj R. , Ferreira Márcia M. C.
Published: April 2007

Internet surfing for the word chemometrics in national languages and, in the Science Citation Index (SCI), searching for articles containing chemometr * were performed. The bibliometric, webometric, and country development descriptors from literature were then treated by Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). In total, 82 written and 127 pronunciation forms of chemometrics were found in 48 languages worldwide. The forms ending in ‘‐y’ (chemometry) and ‘‐ics’ (chemometrics) can be grouped into at least three groups (I, J, K). Scientific collaboration, country development, geography, history, and language were shown to be important determinants in creation of form(s) of chemometrics in a particular country or language. PCA and HCA show that tradition in chemometrics, level of country development, and its scientific production are important for the existence of chemometric societies and laboratories worldwide. Today, the world tends toward becoming more homogeneous with respect to chemometric activity, and will reach a corresponding normal distribution in about 70 years from now. Copyright © 2007 John Wiley & Sons, Ltd.
An adaptive regression adjusted monitoring and fault isolation scheme
Authors: Liu Hancong , Jiang Wei , Tangirala Arun , Shah Sirish
Published: April 2007

A new method is proposed in this work to detect and isolate faults in a system consisting of multivariate normal data. The proposed method reduces the variable dimension via a T2 decomposition and combines multivariate monitoring and diagnosis in a unified approach. An adaptive regression adjusted (ARA) chart is introduced to utilize the diagnosis result in order to improve the monitoring scheme. Once an out‐of‐control alarm is detected, the fault isolation can be done directly. Copyright © 2007 John Wiley & Sons, Ltd.
Calibrating the concentration from a serial dilution process
Authors: Liao Jason J. Z. , Duan Fenghai
Published: April 2007

In a chemistry or biology laboratory, people often dilute the sample sequentially to obtain preparations. This serial dilution process usually generates dilution error which results in correlated concentrations. This kind of error is being neglected in current practice and it can lead to a biased estimate. In this paper, we propose a linear calibration with correlated covariates that takes this serial dilution error into consideration when estimating the concentration of the unknown sample. A consistent and asymptotically unbiased estimator with asymptotic normality is derived. One particular appeal of this approach is that the estimate can be obtained with existing SAS® procedures. A simulation study shows that the new approach performs much better than the current practice with respect to the bias, the mean squared error (MSE), and the coverage probability. It also indicates that the effect of the serial dilution is controlled by an index, which has a similar role as the signal‐to‐noise ratio in a simple regression. A real data set is used to demonstrate the advantage of the proposed approach. Copyright © 2007 John Wiley & Sons, Ltd.
On rotational ambiguity in model‐free analyses of multivariate data
Authors: Vosough Maryam , Mason Caroline , Tauler Romà , Jalali‐Heravi Mehdi , Maeder Marcel
Published: April 2007

Rotational ambiguity is a central but not well investigated problem in all soft‐modelling analyses of multivariate data. A novel method which is based on Resolving Factor Analysis (RFA) is proposed. Completely general and exhaustive results are presented for the two‐component case. In particular the effects of noise and global analysis of series of measurements are investigated. Copyright © 2007 John Wiley & Sons, Ltd.
Crispness assessment of roasted almonds by an integrated approach to texture description: texture, acoustics, sensory and structure
Authors: Varela P. , Chen J. , Fiszman S. , Povey M. J. W.
Published: April 2007

This study combines passive acoustic and mechanical measures of sensory crispness. We show that the acoustic signal is dominated by ‘bursts’ of sound associated with crack failure events in the product which also release measurable amounts of elastic energy. One‐way analysis of variance (ANOVA) and principal component analysis (PCA) were performed on the sensory, acoustical, mechanical and compositional parameters. We show that this chemometric approach is a powerful method for the objective analysis of large, complex data sets in the context of human sensory studies and the objective measure of a sensory parameter; in this case crispness. We demonstrate that sensory crispness in almonds is an amalgam of acoustic and mechanical effects occurring during chewing. We show that our method is capable of predicting the crispness of roasted almonds. Copyright © 2007 John Wiley & Sons, Ltd.
Peak‐finding partial least squares for the analysis of 1H NMR spectra
Authors: Ammann L. P. , Merritt M. , Sagalowsky A. , Nurenberg P.
Published: April 2007

Metabonomic analysis of biofluids and extracts of biological tissues is increasingly being used to diagnose important metabolic differences induced by toxicity, disease processes or genetic differences. 1H nuclear magnetic resonance (NMR) has been shown to be very useful for monitoring the low‐molecular weight metabolite milieu typical of many systems. In this paper, a rigorous comparison of five different methods of data reduction and classification has been made. The five methods include principal components analysis (PCA) followed by linear discriminant analysis (LDA), PCA followed by logistic regression, a combined peak‐picking‐PCA and LDA algorithm, partial least squares (PLS), and a peak‐picking PLS algorithm. To evaluate these five methods, a data set consisting of 1H NMR spectra of the extracts of 29 malignant renal tumors and 17 normal tissues were analyzed. It was determined that peak‐picking with PLS was the most efficient algorithm for correctly classifying this data set. Also, the peak‐picking algorithm makes identification of the metabolites responsible for establishing class membership easier than with the other methods. A variety of different metabolites, including several amino acids and choline containing compounds were identified as markers for malignancy. Copyright © 2007 John Wiley & Sons, Ltd.
Fuzzy‐based purest wavelength selection from spectral data
Authors: Setarehdan Seyed Kamaledin
Published: April 2007

Wavelength selection is usually a useful and sometimes a necessary task in process monitoring using spectroscopic equipment. In this paper, a novel fuzzy‐based purest wavelength selection algorithm from spectral data is presented. The proposed algorithm uses the pure component spectra of all chemical components within the mixture in a fuzzy logic framework to identify the set of the most important wavelengths (the set of the purest wavelengths) for a chemical component of interest. Both synthetic and real (Raman) spectral data sets were employed to evaluate the performance of the proposed algorithm. As a comparative study in the case of the real Raman data, the Evolving Window Factor Analysis (EWFA) technique is applied to both the original spectra and the selected set of the purest wavelengths for a component of interest. The resulting first singular value in EWFA is then compared to the reference concentration trend obtained using the conventional Partial Least Squares (PLS) regression model. The comparison confirms the high quality of the selected set of the purest wavelengths and the effectiveness of the proposed fuzzy‐based algorithm. Copyright © 2007 John Wiley & Sons, Ltd.
The paley‐wiener theorem for the radon transform
Authors: Lax Peter D. , Phillips Ralph S.
Published: April 2007

We prove that the support of a complex‐valued function f in ℝk is contained in a convex set K if and only if the support of its Radon transform k(s, ω) is, for each ω, contained in s ≦ SK (ω); here SK is the support function of the set K. This theorem is used to determine the propagation speeds of hyperbolic differential equations with constant coefficients, to prove the nonexistence of point spectrum for a certain class of partial differential operators, and to give a simple reduction of Lions' convolution theorem to the one‐dimensional convolution theorem of Titchmarsh.
Daytime Sources of Nitrous Acid (HONO) in the Atmospheric Boundary Layer
Authors: Kleffmann Jörg
Published: April 2007

Nitrous acid (HONO) is an important precursor of the hydroxyl radical (OH), the self‐cleaning agent of the atmosphere and a key species in the formation of harmful photooxidants during summer smog. Recent field measurements using very sensitive HONO instruments have shown that daytime HONO concentrations are much higher than has been assumed previously and that the contribution of HONO to the radical formation was underestimated in the past. A strong photochemical HONO source has been proposed, which contributes to the primary OH radical production up to 56 %. These exciting results initiated new laboratory studies, in which new sources of HONO have been identified. It is demonstrated that HONO is photochemically formed 1) on surfaces treated with nitric acid, 2) by reduction of NO2 on photosensitized organic surfaces like humic acids and c) in the gas phase photolysis of ortho‐substituted nitroaromatics. Although significant uncertainties still exist on the exact mechanisms, these additional sources might explain daytime observations in the atmosphere and demonstrate that HONO should be generally measured in field campaigns, besides other radical sources.
Eye movement desensitization and reprocessing in the psychological treatment of trauma‐based psychogenic non‐epileptic seizures
Authors: Kelley Susan D. M. , Benbadis Selim
Published: April 2007

Little is known about the types of mental health treatment that are most effective for psychogenic non‐epileptic seizure (PNES) patients who have high rates of comorbid post‐traumatic stress disorder (PTSD) and dissociation. Eye movement desensitization and reprocessing (EMDR) has proved to be effective in the treatment of PTSD, anxiety states, dissociative symptoms and somatoform disorders. This study, which utilized a non‐controlled qualitative multiple revelatory case design, integrates EMDR into the psychological treatment of PNES patients with confirmed trauma experiences. With EMDR targeting trauma and dissociative symptoms in three patients, PNES were extinguished in two. Those patients have remained seizure‐free for 12–18 months. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of patient dissatisfaction with the therapist on group therapy outcome
Authors: Ogrodniczuk John S. , Joyce Anthony S. , Piper William E.
Published: April 2007

This study had three objectives concerning patients' dissatisfaction with their psychotherapist. The first was to compare patient dissatisfaction with the therapist in interpretive and supportive group therapies. The second was to investigate the relationship between dissatisfaction and treatment outcome. The third was to examine the quality of object relations (QOR) as a moderator of the effect of dissatisfaction on treatment outcome. The study utilized data from 107 patients with complicated grief who participated in a randomized trial of interpretive and supportive group therapies. Patients reported a greater dissatisfaction in interpretive therapy than in supportive therapy. Dissatisfaction was inversely related to improvement in supportive therapy, but not in interpretive therapy. Further, QOR moderated the effect of dissatisfaction on treatment outcome in supportive therapy. The findings suggest that, for certain patients, dissatisfaction with one's therapist may have an adverse effect on one's ability to benefit from group therapy. Copyright © 2007 John Wiley & Sons, Ltd.
Role of FNA cytology and immunochemistry in the diagnosis and management of medullary thyroid carcinoma: Report of six cases and review of the literature
Authors: Bhanot Punam , Yang Jack , Schnadig Vicki J. , Logroño Roberto
Published: April 2007

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine thyroid malignancy. This study retrospectively reviewed 10 fine‐needle aspiration samples from six MTC patients. Aspirated specimens were from thyroid (3), cervical lymph nodes (5), left lung (1), and anterior chest wall (1). Cytomorphology consisted predominantly of plasmacytoid cells (3 cases), spindle cells (2 cases), and epithelioid cells (1 case). However, all specimens had a mixture of other cell types and “salt and pepper” chromatin. Only one specimen showed Congo‐red‐positive amyloid. Calcitonin was expressed in 7/7 specimens. Four patients underwent surgical excision and MTC was confirmed in all four. Follow‐up studies included serum calcitonin (3/6 cases) and imaging (2/6 cases). One patient had MTC associated with multiple endocrine neoplasia IIA syndrome and one had familial MTC with a history of MTC in mother. In conclusion, the cytomorphology of MTC is typical and calcitonin immunostain is a reliable method for confirming primary or metastatic MTC. Early cytological diagnosis of MTC positively impacted patient management. Follow‐up with serum calcitonin and imaging is helpful in the early detection of recurrences. Diagn. Cytopathol. 2007;35:285–292. © 2007 Wiley‐Liss, Inc.
Endoscopic ultrasound‐guided biopsies of pancreatic masses: Comparison between fine needle aspirations and needle core biopsies
Authors: Yun Shine S. , Remotti Helen , Vazquez Madeline F. , Crapanzano John P. , Saqi Anjali
Published: April 2007

Endoscopic ultrasound‐guided fine needle aspiration (EUS‐guided FNA) is a highly sensitive and specific method for diagnosing pancreatic masses. Alternatively, EUS‐guided needle core biopsies (NCB) have also been introduced. We sought to determine efficacies of pancreatic EUS‐guided FNAs and NCBs. Records of consecutive EUS‐guided FNAs received over a 24‐mo‐period were reviewed. Cases with concurrent NCBs were selected for the study. The diagnoses from the two modalities were compared and designated concordant (CC) or discordant (DC). Of 252 cases, 52 had concurrent NCBs. The final diagnoses included primary and secondary tumors. Of the 52 cases, 29/52 (55.8%) were CC and 23/52 (44.2%) were DC. The sensitivities for FNAs and NCBs were 95.0% and 67.6%, respectively. Both modalities were 100% specific. Direct comparison between EUS‐guided FNAs and NCBs demonstrated that the former are more sensitive for diagnosing pancreatic neoplasms, both primaries and metastases. There was no correlation between CC/DC cases and type of neoplasm. Diagn. Cytopathol. 2007;35:276–282. © 2007 Wiley‐Liss, Inc.
Characteristics and key findings for ‘Conjugate vaccines for preventing meningococcal C meningitis and septicaemia’
Authors: van Dalen Elvira , Kremer Leontien
Published: April 2007

These are the characteristics and key findings for a Cochrane review, published in this issue of EBCH, first published as: Conterno LO, Silva Filho CR, Rüggeberg JU, Heath PT. Conjugate vaccines for preventing meningococcal C meningitis and septicaemia. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD001834. DOI: 10.1002/14651858.CD001834.pub2.

Further information for this Cochrane review is available in this issue of EBCH in the accompanying EBCH Summary and Commentary articles. Copyright © 2007 John Wiley & Sons, Ltd.
Characteristics and key findings for ‘Oral versus intravenous rehydration for treating dehydration due to gastroenteritis in children’
Authors: van Dalen Elvira , Kremer Leontien
Published: April 2007

These are the characteristics and key findings for a Cochrane review, published in this issue of EBCH, first published as: Hartling L, Bellemare S, Wiebe N, Russell K, Klassen TP, Craig W. Oral versus intravenous rehydration for treating dehydration due to gastroenteritis in children. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD004390. DOI: 10.1002/14651858.CD004390.pub2.

Further information for this Cochrane review is available in this issue of EBCH in the accompanying EBCH Summary and Commentary articles. Copyright © 2007 John Wiley & Sons, Ltd.