bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic polymorphisms and esophageal cancer risk
Authors: Hiyama Toru , Yoshihara Masaharu , Tanaka Shinji , Chayama Kazuaki
Published: August 2007

The aim of this paper is to review and evaluate, in a comprehensive manner, the published data regarding the contribution of genetic polymorphisms to risk of esophageal cancer, including squamous cell carcinoma (SCC) and adenocarcinoma, in humans. All relevant studies available in MEDLINE and published before February 2007 were identified. Studies carried out in humans and that compared esophageal cancer patients with at least 1 standard control group were considered for analysis. One‐hundred studies and 3 meta‐analyses were identified. Eighty (80%) studies were conducted in Asian countries, particularly China including Taiwan (60 (60%) studies). The most intensively examined genes were those encoding carcinogen metabolic enzymes. The most widely studied gene was GSTM1 (15 studies), followed by ALDH2 (11 studies). ALDH2, MTHFR C677T, CYP1A1 Ile/Val, CYP1A1MspI, CYP2E1, GSTP1, GSTM1 and GSTT1 were examined by meta‐analyses and significant relations were found between ALDH2*1*2 and the CYP1A1 Val allele and increased risk of esophageal cancer. In addition, increased risk of esophageal SCC was consistently associated with the ADH2*1*2 and the p53 codon 72 Pro/Pro genotypes. Cohort studies that simultaneously consider multiple genetic and environmental factors possibly involved in esophageal carcinogenesis are needed to ascertain not only the relative contribution of these factors to tumor development but also the contributions of their putative interactions. © 2007 Wiley‐Liss, Inc.
Integrating spirituality and psychotherapy: Ethical issues and principles to consider
Authors: Plante Thomas G.
Published: August 2007

Professional and scientific psychology appears to have rediscovered spirituality and religion during recent years, with a large number of conferences, seminars, workshops, books, and special issues in major professional journals on spirituality and psychology integration. The purpose of this commentary is to highlight some of the more compelling ethical principles and issues to consider in spirituality and psychology integration with a focus on psychotherapy. This commentary will use the American Psychological Association's (2002) Ethics Code and more specifically, the RRICC model of ethics that readily applies to various mental health ethics codes across the world. The RRICC model highlights the ethical values of respect, responsibility, integrity, competence, and concern. Being thoughtful about ethical principles and possible dilemmas as well as getting appropriate training and ongoing consultation can greatly help the professional better navigate these challenging waters. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 891–902, 2007.
Does integrated trauma‐informed substance abuse treatment increase treatment retention?
Authors: Amaro Hortensia , Chernoff Miriam , Brown Vivian , Arévalo Sandra , Gatz Margaret
Published: August 2007

This article presents findings from a quasi‐experimental, nonrandomized group design study that explored whether trauma‐enhanced substance abuse treatment results in longer residential treatment stays and improved outcomes compared with treatment‐as‐usual. We used a subsample (N = 461) of participants in the Women, Co‐Occurring Disorders and Violence Study, which was sponsored by the Substance Abuse and Mental Health Services Administration. The intervention group was 31% less likely to discontinue treatment within 4 months. Baseline mental health and trauma symptoms and alcohol and drug severity scores predicted neither overall length of time in treatment nor differences in retention between intervention and comparison groups. Substance abuse and mental health symptoms improved with increased duration of treatment, particularly for women with more severe baseline symptoms. © 2007 Wiley Periodicals, Inc. J Comm Psychol 35: 845–862, 2007.
Small RNAs: Regulators and guardians of the genome
Authors: Chu Chia‐Ying , Rana Tariq M.
Published: August 2007

Small non‐coding RNAs comprise several classes and sizes, but all share a unifying function in cellular physiology: epigenetic regulation of gene expression. Here, we review the salient aspects of recent studies on the biogenesis and function of three classes of small RNAs: miRNAs, siRNAs, and piRNAs. Although the mechanisms are becoming clear by which siRNA‐triggered mRNA cleavage silences genes, more studies are needed on several issues regarding miRNA‐mediated translation repression. Piwi proteins have been suggested to co‐operate in amplifying piRNA biogenesis to maintain transposon silencing in the germ line genome, but details of this process are still unknown as well as the functional consequences of piRNA expression at discrete genomic loci. J. Cell. Physiol. 213: 412–419, 2007. © 2007 Wiley‐Liss, Inc.
Preparation of [11C]methyl nona‐fluorobutyl‐1‐sulfonate ([11C]MeONf) and its use in the synthesis of [11C]‐6‐OH‐BTA‐1
Authors: Jolly Dean , Lakhrissi Younes , Kovacevic Miriam M. , Chertkow Howard , Schirrmacher Ralf
Published: August 2007

The rapid, simple and high‐yield synthesis of the extraordinarily reactive 11C‐methylating agent, [11C]methyl nona‐fluorobutyl‐1‐sulfonate ([11C]MeONf), and its use in the synthesis of the promising β‐amyloid imaging agent, [11C]‐6‐OH‐BTA‐1, is reported. In terms of radioactive methylation yields, [11C]MeONf seems to surpass [11C]methyl trifluoromethansulfonate ([11C]MeOTf) as a methylating agent in this particular case giving the 11C‐labelled compound in high‐preparative radiochemical yields between 27 and 29% EOS with a minimum formation of radioactive by‐products. Copyright © 2007 John Wiley & Sons, Ltd.
Measurement equivalence of executives' performance ratings for same‐ and opposite‐gender dyads
Authors: Etchegaray Jason M.
Published: August 2007

The measurement equivalence of performance ratings from different raters is important to establish if researchers and practitioners want to have confidence that raters are using the performance measurement system in the same way. The purpose of the present study was to examine the measurement equivalence of performance ratings from male and female direct reports. Women and men executives from various organizations participated in a multisource assessment process for feedback and development purposes and were rated by both women and men direct reports. The results indicated gender equivalence for direct reports' ratings of men and women executives, meaning that regardless of gender, raters provided ratings using the same psychological metric. The implications and limitations of the study are discussed.
Investigation of Thermal Aging of Polyamide 4,6 by1H Solid‐State NMR
Authors: Demco Dan E. , Litvinov Victor M. , Rata Gabriel , Popescu Crisan , Phan Kim‐Hô , Schmidt Angelika , Blümich Bernhard
Published: August 2007

The thermal aging of polyamide 4,6 was investigated by DSC, SEM, WAXS, and1H solid‐state NMR. Phase composition, chain mobility, morphology, and domain sizes were determined as a function of aging time. Proton transverse magnetization relaxation was measured at low resonance frequency,1H wide‐line NMR spectra and1H spin‐diffusion experiments were made at high resonance frequency. The NMR investigation shows that the aging process affects the rigid (crystalline), semi‐rigid (crystalline/amorphous interface), and the mobile (amorphous) fraction of polyamide 4,6. The amount of rigid (crystalline) fraction increases by about 10% upon aging at 200 °C for 1 000 h at the expense of the interfacial fraction. Chain mobility in crystalline phase is reduced upon aging suggesting perfections of the crystalline order.

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Hydroformylation with Dendritic‐Polymer‐Stabilized Rhodium Colloids as Catalyst Precursors
Authors: Tuchbreiter Lydie , Mecking Stefan
Published: August 2007

Hydroformylation of 1‐hexene with rhodium colloids stabilized by poly(ethylene imine) amides with a hyperbranched polyamine core and a lipophilic periphery is reported. The catalyst selectivity for aldehydes increases with increasing temperature or pressure. The ratio of linear to branched aldehydes decreases with increasing temperature. At 80 °C and 90 atm, 1‐hexene is converted completely with 96% selectivity for aldehydes, with a ratio of linear/branched aldehydes of 58:42. Turnover numbers up to 3 × 104 (calculated with respect to the entire amount of Rh present) were observed. The results indicate that the catalyst precursor colloids serve as a reservoir for the formation of soluble Rh(I) complexes as the active species.

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Polymers with Side Chain N‐Alkoxy Pyridinium Ions as Precursors for Photoinduced Grafting and Modification Processes
Authors: Durmaz Yasemin Yuksel , Yilmaz Gorkem , Yagci Yusuf
Published: August 2007

A combination of NMP and photoinitiated polymerization is suggested as a new strategy for the synthesis of graft copolymers. First, P(S‐co‐CMS) copolymer backbones with different chloromethyl content are prepared by NMP. The chloro functions are then converted into photosensitive 4‐phenyl pyridinium‐N‐oxide ion functions. Finally, these photoactive polymers are irradiated in the presence of MMA to obtain the graft copolymers. They and their precursors at various stages are characterized by spectroscopy and GPC. It is demonstrated that the irradiation of photoactive polymers in the presence of a hydrogen donors such as THF facilitates the conversion of pyridinium ions to hydroxyl groups.

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Macromol. Rapid Commun. 15/2007
Authors: Bédard Matthieu , Skirtach Andre G. , Sukhorukov Gleb. B.
Published: August 2007

Cover: Optically‐adressable polymeric microshells made principally of poly(allylamine hydrochloride) and of an azobenzene‐containing polyelectrolyte (PAzo) were produced using the layer‐by‐layer assembly technique. In water, these hollow containers are permeable to labeled polymers. However, by irradiating the loaded capsules with a light source of sufficient intensity, the former shrink and become impermeable to the dye. The supernatant may then be removed and the microshells along with their encapsulated material resuspended in water. Further details can be found in the article by M. Bédard,* A. G. Skirtach, G. B. Sukhorukov on page 1517.
The frequency and size of price adjustment: microeconomic evidence
Authors: Rátfai Attila
Published: August 2007

This paper presents direct, non‐parametric microeconomic evidence on pricing behavior and evaluates the findings in light of theories of nominal price rigidity. The main issues examined include the durability of price quotations and the size of price changes. The analysis is based on a unique high‐frequency panel data set of consumer prices recorded in 1993–1996 in Hungary. The results indicate that price adjustment patterns in the sample are primarily consistent with implications of two‐sided (S,s) pricing models. Copyright © 2007 John Wiley & Sons, Ltd.
Sustained relief of dystonia following cessation of deep brain stimulation
Authors: Hebb Matthew O. , Chiasson Paula , Lang Anthony E. , Brownstone Robert M. , Mendez Ivar
Published: August 2007

We describe the unusual clinical course of a patient with cranial dystonia (i.e., Meige syndrome) and additional upper limb involvement, who developed sustained relief of motor symptoms following cessation of a prolonged course of bilateral pallidal deep brain stimulation (DBS). Early response to therapy proved titratable and reversible; however, the patient gained independence from DBS in the fifth postoperative year and has since been more than a year without treatment or exacerbation of motor symptoms. Among the potential explanations for these neurological benefits lies the intriguing possibility that DBS therapy may have the capacity to induce plastic change that lessens or obviates the need for further treatment in susceptible patients. © 2007 Movement Disorder Society
Myoclonus or tremor in orthostatism: An under‐recognized cause of unsteadiness in Parkinson's disease
Authors: Leu‐Semenescu Smaranda , Roze Emmanuel , Vidailhet Marie , Legrand André‐Pierre , Trocello Jean‐Marc , Cochen Valérie , Sangla Sophie , Apartis Emmanuelle
Published: August 2007

Patients with Parkinson's disease (PD) often complain of unsteadiness. This can occur as the result of various neurological dysfunctions, including changes in postural adjustments, loss of postural reflexes, axial akinesia and rigidity, freezing and/or postural hypotension. In some cases these symptoms remain unexplained, and rare cases of unsteadiness have been attributed to tremor on standing. To delineate this condition, we investigated 11 consecutive PD patients with unexplained unsteadiness because of tremor on standing, seen in our department over a 6‐year period. All the patients had detailed clinical and electrophysiological investigations based on surface polygraphic electromyographic recordings. Four patients had fast orthostatic tremor (13–18 Hz), one had intermediate orthostatic tremor (8–9 Hz), and three had slow orthostatic tremor (4–6 Hz). The remaining 3 patients had orthostatic myoclonus, a condition that has not previously been reported in PD. Patients with fast tremor improved on clonazepam. Patients with slow tremor and myoclonus improved on levodopa and sometimes benefited further when clonazepam was added. These observations show the usefulness of neurophysiological investigations for diagnosing and treating unexplained unsteadiness in Parkinson's disease. © 2007 Movement Disorder Society
Partial Noether operators and first integrals via partial Lagrangians
Authors: Kara A. H. , Mahomed F. M. , Naeem I. , Wafo Soh C.
Published: August 2007

The notions of partial Lagrangians, partial Noether operators and partial Euler–Lagrange equations are used in the construction of first integrals for ordinary differential equations that need not be derivable from variational principles. We obtain a Noether‐like theorem that provides the first integral by means of a formula which has the same structure as the Noether integral. However, the invariance
condition for the determination of the partial Noether operators is different as we have a partial Lagrangian and as a result partial Euler–Lagrange equations. Applications given include those that admit a standard Lagrangian such as the harmonic oscillator, modified Emden and Ermakov–Pinney equations and systems of two second‐order equations that do not have standard Lagrangians. Copyright © 2007 John Wiley & Sons, Ltd.
A large parasitengonid mite (Acari, Erythraeoidea) from the Early Cretaceous Crato Formation of Brazil
Authors: Dunlop J. A.
Published: August 2007

Abstract. A new large, fossil mite (Arachnida: Acari), Pararainbowia martilli n. gen. n. sp., is described from the Early Cretaceous (Aptian) Crato Formation from Ceará State, Brazil. It is assigned to the Cohort Parasitengona and the superfamily Erythraeoidea, some extant members of which can reach up to seven millimetres in body length. Given that doubts have been raised about the identity of putative Crato feather mite eggs, this new fossil represents the first unequivocal record of Acari from the Crato Formation, the first non-amber record of an erythraeoid mite and the oldest named example of this superfamily. Fossil erythraeoids from Mesozoic and Tertiary ambers are briefly reviewed – including a widely overlooked Late Cretaceous species – with comments on Mesozoic mites in general. Thirteen Baltic amber erythraeoids have been formally described, but much unstudied material from various amber sources remains. Ein neues großes Milbenfossil (Arachnida: Acari), Pararainbowia martilli n. gen. n. sp., wird aus der Crato Formation (Unterkreide, Aptium) des Ceará Gebietes in Brasilien beschrieben. Es wird der Kohorte Parasitengona und der Überfamilie Erythraeoidea zugeordnet; die modernen Vertreter erreichen eine Körperlänge bis zu sieben mm. Weil die Identität von Federmilbeneiern aus der Crato Formation in Frage gestellt wurde, ist dieser Neufund der erste klare Hinweis von Acari aus der Crato Formation. Es ist die erste erythraeoide Milbe, die nicht aus dem Bernstein stammt sowie das älteste genannte Beispiel dieser Überfamilie. Fossile erythraeoide Milben aus dem Bernstein des Mesozoikum und des Tertiärs werden kurz zusammengefasst – u. a. eine weitgehend übersehene Art aus der Oberkreide – mit allgemeinen Anmerkungen zu den mesozoischen Milben. Dreizehn erythraeoide Milbenarten sind aus dem baltischen Bernstein genannt und beschrieben worden, aber weiteres unbearbeitetes Material von verschiedenen Bernstein-Fundpunkten liegt noch vor. doi:10.1002/mmng.200700001
First xenacanthid shark from the Pennsylvanian (Moscovian) of the Northern Caucasus (Russia)
Authors: Hampe O. , Ivanov A.
Published: August 2007

Abstract. The occurrence of Triodus teberdaensis n. sp. teeth from the Pennsylvanian Tolstiy Bugor Formation (Moscovian) of Karachay-Cherkess Republic is the first evidence of xenacanthid remains from the Caucasus. The new species was found in carbonate sediments interpreted as resulting from short-term transgressions during the Pennsylvanian regressive phase – further evidence that xenacanthids, predominantly adapted to freshwater, have also lived in marine environments. Das Auftreten von Zähnen des Triodus teberdaensis n. sp. in der oberkarbonischen Tolstiy Bugor Formation (Moscovium) von Karatschai-Tscherkessien ist der erste Nachweis xenacanthider Überreste aus dem Kaukasus. Die neue Art wurde in karbonatischen Sedimenten, die als Transgressions-Intervalle innerhalb der globalen Oberkarbon-Regression interpretiert werden, abgelagert – ein Beleg dafür, dass die überwiegend aus Süßwasserablagerungen bekannten Xenacanthiden auch im marinen Milieu lebten. doi:10.1002/mmng.200700004
An improved perturbation method for stochastic finite element model updating
Authors: Hua X. G. , Ni Y. Q. , Chen Z. Q. , Ko J. M.
Published: August 2007

In this paper, an improved perturbation method is developed for the statistical identification of structural parameters by using the measured modal parameters with randomness. On the basis of the first‐order perturbation method and sensitivity‐based finite element (FE) model updating, two recursive systems of equations are derived for
estimating the first two moments of random structural parameters from the statistics of the measured modal parameters. Regularization technique is introduced to alleviate the ill‐conditioning in solving the equations. The numerical studies of stochastic FE model updating of a truss bridge are presented to verify the improved perturbation method under three different types of uncertainties, namely natural randomness, measurement noise, and the combination of the two. The results obtained using the perturbation method are in good agreement with, although less accurate than, those obtained using the Monte Carlo simulation (MCS) method. It is also revealed that neglecting the correlation of the measured modal parameters may result in an unreliable estimation of the covariance matrix of updating parameters. The statistically updated FE model enables structural design and analysis, damage detection, condition assessment, and evaluation in the framework of probability and statistics. Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of molecular determinants of angiogenesis and lymphangiogenesis in lymph node metastases and in primary tumours of patients with breast cancer
Authors: Van den Eynden GG , Van der Auwera I , Van Laere SJ , Trinh XB , Colpaert CG , van Dam P , Dirix LY , Vermeulen PB , Van Marck EA
Published: August 2007

Angiogenesis and lymphangiogenesis are complex processes, driven by multiple factors. In primary breast tumours (PTs), VEGFA, ‐C and ‐D are the most important (lymph)angiogenic factors. The induction of lymphangiogenesis in axillary lymph node (LN) metastases of patients with breast cancer was described recently. To compare the molecular determinants of (lymph)angiogenesis in LN metastases and PTs of breast cancer patients, RNA was isolated from formalin‐fixed, paraffin‐embedded tissue sections of a metastatically involved and uninvolved LN and the PT from 26 lymph node‐positive patients. The expression of 12 (lymph)angiogenic markers was measured by qRT–PCR. Expression was correlated with tumour cell proliferation, angiogenesis and lymphangiogenesis, quantified by tumour cell proliferation fraction (TCP%) and (lymphatic) endothelial cell proliferation fraction [(L)ECP%]. TCP%, ECP% and LECP% were assessed on immunohistochemical double stains for CD34/Ki‐67 and D2‐40/Ki‐67, respectively. In involved LNs, the relative gene expression levels of PROX1 (p < 0.001) and FGF2 (p = 0.008) were decreased and the expression levels of VEGFA (p = 0.01) and PDGFB (p = 0.002) were increased compared to uninvolved LNs. The expression of most markers was increased in PTs compared to involved LNs. In metastatically involved LNs, the expression of VEGFA correlated with ECP% (r = 0.54, p = 0.009) and LECP% (r = 0.76, p < 0.001). In PTs, VEGFA correlated only with ECP% (r = 0.74, p < 0.001). VEGFD correlated with peritumoural LECP% (r = 0.61, p = 0.001) and with VEGFC (r = 0.78, p < 0.001). Linear regression analysis confirmed the expression of VEGFA as an independent predictor of ECP% in both PTs and LN metastases and of LECP% in LN metastases. The expression of VEGFD, but not of VEGFA, independently predicted peritumoural LECP% in PTs. Our results confirm existing data that, in PTs, angiogenesis and lymphangiogenesis are respectively driven by VEGFA and VEGFD. In contrast, in LN metastases, both processes seem to be driven by VEGFA. Lymphangiogenesis in PTs and in LN metastases might thus be driven by different factors. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of a poly(dimethylsiloxane) modified polyolefin additive on the processing and surface properties of LLDPE
Authors: Zhu S.‐H. , McManus N.T. , Tzoganakis C. , Penlidis A.
Published: August 2007

A polydimethylsiloxane (PDMS) modified polyolefin (obtained by reacting an ethylene‐ethyl acrylate‐maleic anhydride (EEAMA) copolymer with an amine terminated PDMS in the melt phase) was used as a processing aid to facilitate the extrusion of linear low density polyethylene (LLDPE). In blends of LLDPE and PDMS modified polyolefin (PMPO), apparent viscosity and shear stress at the die wall are reduced in comparison to pure LLDPE, and extrusion instabilities are delayed as evidenced by the fact that extrudate surface roughness only occurs at higher shear rates when the additive is present. A higher PDMS content in the PMPO leads to a more pronounced delay of extrusion instabilities. Single‐screw extrusion of LLDPE compounds with a PMPO results in nearly doubled throughput per unit input energy. The reduction of viscosity and improvements in extrudate quality are attributed to the decreasing surface free energy of the PMPO with an increasing PDMS content, as determined by contact angle measurements. Chemical composition analysis of the extrudate surface and cross‐section reveals silicon enrichment at the surface. The friction coefficients of pure PMPO and PMPO/LLDPE blends are measured and found to decrease as a result of the presence of PDMS. POLYM. ENG. SCI., 47:1309–1316, 2007. © 2007 Society of Plastics Engineers
Processability of LLDPE/LDPE blends: Capillary extrusion studies
Authors: Delgadillo‐Velázquez O. , Hatzikiriakos S.G.
Published: August 2007

The processing behavior of a number of linear low‐density polyethylenes/low density polyethylene (LLDPE/ LDPE) blends with emphasis on the effects of long chain branches is presented. A Ziegler‐Natta linear low‐density polyethylene was blended with four low‐density polyethylene LDPE's having distinctly different molecular weights. The weight fractions of the LDPEs used in the blends were 1, 5, 10, 20, 50, and 75 wt%. Capillary extrusion reveals that the onset of sharkskin and gross melt fracture are slightly influenced with the addition of LDPE into LLDPE. However, the amplitude of the oscillations in the stick‐slip flow regime was found to scale well with the weight fraction of LDPE. Amounts as low as 1 wt% LDPE have a significant effect on the amplitude of pressure oscillations. These effects are clearly due to the presence of long chain branching (LCB); furthermore, it was observed that the onset of this flow regime was shifted to higher shear rates with increase of LDPE content. On the other hand, shear rheology is not sensitive to detect addition of small levels of LDPE up to 20 wt%. Extensional rheology can detect levels of LDPE as small as 1 wt% only at high Hencky strain rates (typically greater than 5s−1) and only for certain blends, typically those that contain LDPE of high molecular weight. It is suggested that the magnitude of oscillations in the oscillating melt fracture flow regime is a sensitive method capable of detecting low levels of LCB. POLYM. ENG. SCI., 47:1317–1326, 2007. © 2007 Society of Plastics Engineers
Effects of a tert‐butylphenylene substituent on the structure and optical, fluorescent and thermal properties of the poly(p‐phenylenevinylene) derivatives
Authors: Chang Hung‐Te , Lee Hsun‐Tsing , Chang En‐Chiuan , Yeh Mou‐Yung
Published: August 2007

Two soluble fluorescent polymers, poly(2‐decyloxy‐5‐(4′‐tert‐butylphenyl)‐1,4‐phenylenevinylene) (DtBP‐PPV) and poly(2‐decyloxy‐1,4‐phenylenevinylene) (DO‐PPV), were prepared by a method similar to the Gilch procedure. The DtBP‐PPV and DO‐PPV have a same chemical structure except for the conjugated tert‐bytulphenyl substituents in the former. The polymers are characterized by using 1H NMR, FTIR, UV–vis, photoluminescence (PL), and electroluminescence (EL) spectroscopies and thermogravimetric analysis (TGA). The 1H NMR spectra show no tolane‐bis‐benzyl (TBB) structure defects in DtBP‐PPV but some in DO‐PPV. Both UV–vis absorption and PL emission peaks of the DtBP‐PPV exhibit a red‐shift phenomenon as compared with those of the DO‐PPV. Moreover, with the DtBP‐PPV and DO‐PPV acting as light‐emitting polymers separately, EL devices were fabricated with a sequential lamination of ITO/PEDOT/DtBP‐PPV (or DO‐PPV)/Ca/Ag. The DtBP‐PPV‐based device shows a lower turn‐on voltage, a longer EL emission wavelength, and a higher brightness than the DO‐PPV‐based device. The maximum brightness of DtBP‐PPV‐based device is 57 cd/m2 at an applied voltage of 12 V. POLYM. ENG. SCI., 47:1380–1387, 2007. © 2007 Society of Plastics Engineers
Carrageenan‐g‐poly(acrylamide)/poly(vinylsulfonic acid, sodium salt) as a novel semi‐IPN hydrogel: Synthesis, characterization, and swelling behavior
Authors: Pourjavadi Ali , Ghasemzadeh Hossein
Published: August 2007

A semi‐interpenetrating polymer network (semi‐IPN) hydrogel based on kappa‐carrageenan (κC) and poly (vinylsulfonic acid, sodium salt) (PVSA) was prepared by graft copolymerization of acrylamide (AAm) using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. FTIR spectroscopy was used for confirming the structure of the final product. It was found that the chemical composition of the Semi‐IPN hydrogel is equal to the initial homopolymers and monomer feed compositions. The swelling capacity of the hydrogel was shown to be affected by the MBA, APS, and AAm concentration as well as κC/PVSA weight ratio. The swelling behavior of the hydrogel was also investigated in various pHs and salt solutions. Since the highly swelling biopolymer‐based hydrogel exhibits low salt‐sensitivity, it may be referred to as an anti‐salt superabsorbent hydrogel. The swelling kinetics of the superabsorbent hydrogels was studied as well. POLYM. ENG. SCI., 47:1388–1395, 2007. © 2007 Society of Plastics Engineers
Mechanical, dielectric, and magnetic properties of the silicone elastomer with multi‐walled carbon nanotubes as a nanofiller
Authors: Park Il‐Seok , Kim Kwang J. , Nam Jae‐Do , Lee Joonsoo , Yim Woosoon
Published: August 2007

Silicone elastomer and multi‐walled carbon nanotubes (MWCNTs) composites, applicable as actuators and controllable dampers, were studied. Dynamic mechanical analysis (DMA) and vibrating sample magnetometry (VSM) were used to investigate the mechanical and magnetic properties of silicone elastomers and MWCNTs composites. Also, measurement of their dielectric property was conducted. The addition of MWCNT was able to tailor the damping and dielectric properties of the silicone elastomer. In this study, a 0.7 wt% of MWCNT composite demonstrated an attractive condition for the damping and the dielectric property. Exceedingly, the modulus increased with the application of a magnetic field. The good filler effect with the small addition of the MWCNTs content is caused by their unique structure, catalytic effect, and magnetic property. POLYM. ENG. SCI., 47:1396–1405, 2007. © 2007 Society of Plastics Engineers
Correlation between different microstructural parameters and tensile modulus of various polyethylene blown films
Authors: Fatahi Shokoh , Ajji Abdellah , Lafleur Pierre G.
Published: August 2007

The objective in this study is to establish a model for the prediction of tensile properties using various types of polyethylene films (LLDPE, HDPE, and LDPE). A series of blown films were produced by varying three process parameters: take‐up ratio, blow‐up ratio, and frost line height. The tensile properties of the resulting films were investigated in relation to their microstructural characteristics. The microstructural parameters were determined by differential scanning calorimetry, wide angle X‐ray diffraction (WAXD) pole figures, SAXS (small angle X‐ray diffraction), and birefringence measurements. The orientation parameters of the films were measured by WAXD and birefringence. They were determined for both crystalline and amorphous phases. The crystalline content, lamellar thickness, and crystal sizes were obtained from DSC and WAXD. The SAXS technique was used to find the average length of the crystalline and amorphous layers. A model for the tensile modulus is proposed and correlated to some structural parameters including crystallinity, orientation factors for crystalline c‐axis and amorphous phase, lamellar thickness, crystal size, the average length of the crystal layer, and long spacing period. The measured modulus and the calculated one were compared and a reasonable agreement was found between them for all series of films. POLYM. ENG. SCI., 47:1430–1440, 2007. © 2007 Society of Plastics Engineers
The effect of density profile on the flexural properties of structural foams
Authors: Barzegari M. Reza , Rodrigue Denis
Published: August 2007

In this study, a comparison is made on the models available to predict the flexural modulus of structural polymer foams. Skin thickness and density profile in the core zone are taken into account to better relate foam morphology with mechanical response. It was found that including skin thickness is not sufficient to predict flexural moduli with high levels of precision and thus a transition zone between the skin and the core must be included. To this end, a single continuous equation is proposed to represent the complete density profile, which enabled us to predict our experimental data within 3%. POLYM. ENG. SCI., 47:1459–1468, 2007. © 2007 Society of Plastics Engineers
Temperature and pressure dependence of the free volume in the perfluorinated polymer glass CYTOP: A positron lifetime and pressure‐volume‐temperature study
Authors: Dlubek G. , Pionteck J. , Sniegocka M. , Hassan E. M. , Krause‐Rehberg R.
Published: August 2007

The microstructure of the free volume was studied for an amorphous perfluorinated polymer (Tg = 378 K). To this aim we employed pressure–volume–temperature experiments (PVT) and positron annihilation lifetime spectroscopy (PALS). Using the Simha‐Somcynsky equation of state the hole free volume fraction h and the specific free and occupied volumes, Vf = hV and Vocc = (1 − h)V, were determined. Their expansivities and compressibilities were calculated from fits of the Tait equation to the volume data. It was found that in the glass Vocc has a particular high compressibility, while the compressibility of Vf is rather low, although h (300 K) = 0.108 is large. In the rubbery state the free volume dominates the total compressibility. From the PALS spectra the hole size distribution, its mean, 〈vh〉, and mean dispersion, σh, were calculated. From a comparison of 〈vh〉 with Vf a constant hole density of Nh′ = 0.25 × 1021 g−1 was estimated. The volume of the smallest representative freely fluctuating subsystem, 〈VSV〉 ∝ 1/σh2, is unusually small. This was explained by an inherent topologic disorder of this polymer. 〈vh〉 and σh show an exponential‐like decrease with increasing pressure P at 298 K. The hole density, calculated from Nh′ = Vf/〈vh〉, seems to show an increase with P which is unexpected. This was explained by the compression of holes in the glass in two, rather than three, dimensions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2519–2534, 2007
Charge transport properties in carbon black/polymer composites
Authors: Psarras G. C.
Published: August 2007

The charge transport properties of polymer matrix–carbon black composites are investigated in this study. Direct current conductivity is examined with varying parameters: the temperature and the conductive filler content. Conductivity data are analyzed by means of percolation theory, and both percolation threshold and critical exponent are determined at each of the examined temperatures. The temperature dependence of conductivity and the agreement of experimental results with the variable range hopping model reveal hopping conduction as the predominant transport mechanism, below and in the vicinity of the critical concentration of carbon black particles. At higher concentrations, the contribution of hopping transport to the overall conductivity is reduced and a balance between hopping and conduction via geometrical contact occurs. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2535–2545, 2007
Pulsed laser deposition of quaternary Cu2ZnSnSe4 thin films
Authors: Adhi Wibowo Rachmat , Soo Lee Eun , Munir Badrul , Ho Kim Kyoo
Published: August 2007

We report the successful growth of quaternary Cu2ZnSnSe4 (CZTSe) thin films by pulsed laser deposition (PLD) using Nd:YAG laser. It was found that CZTSe films atomic ratios were close to target atomic ratios with a slight metal excess and selenium deficiency. Quaternary CZTSe films grew and crystallized as a stannite‐type structure even at room temperature. All CZTSe films showed a p‐type electrical conductivity with a high absorption coefficient of 104–105 cm–1, a bandgap of 1.5 eV and a carrier concentration of the order of 1017–1018 cm–3. These results show that pulsed laser deposition could be employed as a particularly effective deposition method for the preparation of quaternary compounds thin films. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Power and sample size when multiple endpoints are considered
Authors: Senn Stephen , Bretz Frank
Published: August 2007

A common approach to analysing clinical trials with multiple outcomes is to control the probability for the trial as a whole of making at least one incorrect positive finding under any configuration of true and false null hypotheses. Popular approaches are to use Bonferroni corrections or structured approaches such as, for example, closed‐test procedures. As is well known, such strategies, which control the family‐wise error rate, typically reduce the type I error for some or all the tests of the various null hypotheses to below the nominal level. In consequence, there is generally a loss of power for individual tests. What is less well appreciated, perhaps, is that depending on approach and circumstances, the test‐wise loss of power does not necessarily lead to a family wise loss of power. In fact, it may be possible to increase the overall power of a trial by carrying out tests on multiple outcomes without increasing the probability of making at least one type I error when all null hypotheses are true.

We examine two types of problems to illustrate this. Unstructured testing problems arise typically (but not exclusively) when many outcomes are being measured. We consider the case of more than two hypotheses when a Bonferroni approach is being applied while for illustration we assume compound symmetry to hold for the correlation of all variables. Using the device of a latent variable it is easy to show that power is not reduced as the number of variables tested increases, provided that the common correlation coefficient is not too high (say less than 0.75). Afterwards, we will consider structured testing problems. Here, multiplicity problems arising from the comparison of more than two treatments, as opposed to more than one measurement, are typical. We conduct a numerical study and conclude again that power is not reduced as the number of tested variables increases. Copyright © 2007 John Wiley & Sons, Ltd.
Iterative learning control with wavelet filtering
Authors: Merry Roel , van de Molengraft René , Steinbuch Maarten
Published: August 2007

The tracking performance of systems that perform repetitive tasks can be significantly improved using iterative learning control (ILC). During successive iterations, ILC learns a high performance feedforward signal from the measured tracking error. In practical applications, the tracking errors of successive experiments contain a repetitive part and a non‐repetitive part. ILC only compensates for the repetitive part, while the non‐repetitive part also enters the learning scheme and deteriorates the performance of ILC. In this paper, analysis of the tracking error of ILC shows the influence of non‐repetitive disturbances. The disturbances of the last two iterations appear to have the largest influence on the tracking error. In order to remove the non‐repetitive disturbances from the tracking error, a wavelet filtering method is proposed, which identifies and removes the non‐repetitive disturbances by a comparison of the time–frequency content of two error realizations for each iteration of ILC. The wavelet filtered error signal contains only the repetitive disturbances and is used as input for ILC. Both simulations and experiments show that with wavelet filtering, a better tracking performance is obtained together with a feedforward signal that contains significantly less disturbances. Copyright © 2007 John Wiley & Sons, Ltd.
Statistisch begründete Festigkeitskennwerte genieteter Bauteile – statische Festigkeit und Wöhlerlinienkatalog
Authors: Greiner Richard , Taras Andreas , Brunner Helmut
Published: August 2007

Die Bewertung der Tragfähigkeit und Restlebensdauer bestehender Eisenbahn‐ und Straßenbrücken gewinnt in den letzten Jahren immer mehr an Bedeutung. Bei der Ausarbeitung der Richtlinie ONR 24008 stellte sich daher erneut die Frage nach der Festigkeit genieteter Bauteile älterer Stahlbrücken. Im Rahmen eines von den Österreichischen Bundesbahnen initiierten Forschungsvorhabens wurden Ergebnisse von statischen Versuchen und Ermüdungsversuchen an genieteten Bauteilen statistisch ausgewertet. Besonders bei den Ergebnissen von Ermüdungsversuchen zeigte sich, dass eine Klassifizierung der untersuchten Konstruktionsdetails entsprechend ihrer Kerbwirkung sinnvoll ist und zu konsistenten Bemessungslinien führt. Als Ergebnis der Studie liegen Tabellen mit statischen Festigkeitswerten sowie einWöhler‐linienkatalog mit Kerbfällen genieteter Bauteile vor.
Shake table model testing and its application
Authors: Lu Xilin , Fu Gongkang , Shi Weixing , Lu Wensheng
Published: August 2007

This paper presents a study of shake table testing for aseismic design of structure systems. Two reinforced concrete structure models of different scales were used first to implement and demonstrate the similitude concept using available testing equipment. This concept was then applied to a 33‐story reinforced concrete building's scaled model, using multidirectional simulated seismic excitations. The test results were used to evaluate and modify the original design. Some of these results were also verified using field testing after the building's construction was completed. Comparison of the results between the model test and the full‐scale test shows that testing based on dynamic similitude using shake table are useful although not perfect and can provide supplementary data for decision making in engineering design. Copyright © 2007 John Wiley & Sons, Ltd.
Practical issues and solutions on installation of viscoelastic dampers in a 46‐story reinforced concrete building structure
Authors: Ahn Sang‐Kyung , Min Kyung‐Won , Park Ji‐Hun , Lee Sang‐Hyun , Lee Dong‐Guen , Oh Jung‐Keun , Kim Ki‐Soo , Lee Sung‐Kyung
Published: August 2007

The purpose of this study is to evaluate the performance of viscoelastic dampers (VEDs) practically used for enhancing the serviceability of a 46‐story reinforced concrete residential building structure. Considering that a bracing system for the installation of VEDs is not appropriate for a residential building because it occupies a large interior space, a method for installing VEDs at the midspan of a horizontal beam connecting the core and exterior columns is proposed. These VEDs control the total structural response in a similar way to a general outrigger system. The results from numerical analysis indicate that VEDs are effective for reducing not only mean components but also fluctuating ones of wind‐induced responses by providing additional damping as well as stiffness. Copyright © 2007 John Wiley & Sons, Ltd.
A comparison of dynamic nonlinear behavior of ordinary and buckling restrained braced frames subjected to strong ground motion
Authors: Asgarian B. , Amirhesari N.
Published: August 2007

In this paper nonlinear dynamic analyses of 4‐ to 12‐story frames with two types of bracing behavior are performed. In the first series of analyses, the bracing post‐buckling behavior is modeled using a Jain‐phenomenological model. In this model bracing buckled against compressive loading and yielded when subjected to tensile loading. In the second series, buckling restrained brace frames subjected to strong ground motion have been analyzed using elements with a bilinear behavior. The results in terms of story drifts, story shears, story shear versus drift hysteresis behavior and plastic hinge locations were compared. By comparing the response of the frame with the buckling restrained brace and the ordinary brace, better performance was observed for the buckling restrained braced frames. Copyright © 2007 John Wiley & Sons, Ltd.
Creep and shrinkage analysis of reinforced concrete frames by history‐adjusted and shrinkage‐adjusted elasticity moduli
Authors: Au F. T. K. , Liu C. H. , Lee P. K. K.
Published: August 2007

Consideration of the time‐dependent deformations due to creep and shrinkage is often necessary to ensure satisfactory behavior of complex concrete structures. The stresses and deformations of a reinforced concrete frame can be analyzed by the finite element method using time integration. However, as the full stress history prior to each time interval considered is necessary, with the increase in the number of time intervals used, the amount of computations increases dramatically. The concept of age‐adjusted elasticity modulus is further explored to develop new functions for efficient evaluation of time‐dependent behavior of concrete frames. The history‐adjusted elasticity modulus is devised so that stage construction can be modeled more accurately. Likewise, the shrinkage‐adjusted elasticity modulus is introduced to enable shrinkage analysis to be carried out using one single step. The methods can cope with frame structures built and loaded in several stages. Accurate results can be obtained by considering just a few large time intervals instead of those fine time steps used in time integration. Numerical examples are presented to demonstrate the usefulness of the new methods. Copyright © 2007 John Wiley & Sons, Ltd.
Diagnosis of femoral hypoplasia–unusual facies syndrome in the fetus
Authors: Paladini D. , Maruotti G. M. , Sglavo G. , Penner I. , Leone F. , D'Armiento M. R. , Martinelli P.
Published: August 2007

Femoral hypoplasia–unusual facies syndrome (FHUFS) is a rare condition characterized by a variable degree of unilateral or bilateral femoral hypoplasia associated with facial clefting and other minor malformations. The prenatal diagnosis of this condition is possible, but so far has been reported prospectively in only two cases. We review all cases of FHUFS reported in the literature and also describe three cases detected prenatally in the mid‐trimester, underlining the variable expression of the syndrome. The reported association with maternal diabetes mellitus and differential diagnosis with other syndromes characterized by femoral hypoplasia are also discussed. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Effects of Neutrophil Elastase Inhibitor on Progression of Acute Lung Injury Following Esophagectomy
Authors: Ono Satoshi , Tsujimoto Hironori , Hiraki Shu‐ichi , Takahata Risa , Kimura Akifumi , Kinoshita Manabu , Ichikura Takashi , Mochizuki Hidetaka
Published: August 2007

The purpose of this study was to evaluate the effect of sivelestat sodium hydrate, a selective inhibitor of neutrophil elastase in the systemic inflammatory response, pulmonary function, and the postoperative clinical course following esophagectomy. Patients with hypoxia associated with surgical stress in the intensive care unit (ICU) immediately after an esophagectomy were eligible for this study. The degree of hypoxia was calculated according to the ratio of arterial oxygen tension (PaO2) to the fractional concentration of inspired oxygen (FiO2)—PaO2/FiO2. Patients with PaO2/FiO2 < 300 mmHg were enrolled in this study. Seven patients were treated with sivelestat, and 10 were not so treated. The degree of hypoxia, the criteria for systemic inflammatory response syndrome (SIRS), and the postoperative clinical course were compared between the two groups. The postoperative decreases in the PaO2/FiO2 ratio were significantly suppressed in the sivelestat group (p < 0.05, by analysis of variance, or ANOVA). Furthermore, 9 of the 10 control group patients developed SIRS on postoperative day 2, whereas only 2 of 7 of the sivelestat group patients developed SIRS (p < 0.05). The postoperative increases in the heart rate were significantly suppressed in the sivelestat group (p < 0.05, ANOVA). The postoperative decreases in the platelet counts were significantly suppressed in the sivelestat group (p < 0.05, ANOVA). The duration of mechanical ventilation and the length of ICU stay for the sivelestat group were shorter than that for the control group. We demonstrated that the postoperative decreases in the PaO2/FiO2 ratio following esophagectomy were significantly suppressed in the sivelestat‐treated group. This clinical study showed that a neutrophil elastase inhibitor may thus be a potentially useful drug for treating acute lung injury following esophagectomy.