bluuebunny/crossref_metadata_2025 huggingface dataset:
Composition of corrosion layers on a magnesium rare‐earth alloy in simulated body fluids
Authors: Rettig Ralf , Virtanen Sannakaisa
Published: February 2008

In this study, the composition of corrosion product layers on a magnesium rare‐earth alloy in simulated body fluid (m‐SBF) containing albumin in physiological concentration is examined. The time dependence of the composition of the layer is studied. The ions from the body fluid that participate in the corrosion layer formation were identified by analyzing layers formed in different solutions that contain only some of the ions of SBF. The layer composition was analyzed by different complementary methods. We used energy dispersive X‐ray analysis, grazing incidence X‐ray diffraction, and Fourier transform infrared spectroscopy. The morphology of the corrosion layers was studied using scanning electron microscopy and light microscopy. In m‐SBF with and without albumin we found an amorphous layer of carbonated calcium phosphate with some calcium replaced by magnesium. It can be clearly shown that calcium is only deposited in the corrosion layer if phosphates are in the solution. The cross‐sections reveal that there are some sharp crevices in the substrate. The work systematically explores the nature of surface layers on magnesium rare‐earth alloys formed in complex SBFs, with the aim to elucidate the influence of specific electrolyte components on the morphology, structure, and composition of corrosion layers on Mg alloys. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Platelet and endothelial adhesion on fluorosurfactant polymers designed for vascular graft modification
Authors: Tang Chad , Kligman Faina , Larsen Coby C. , Kottke‐Marchant Kandice , Marchant Roger E.
Published: February 2008

A prominent failure mechanism of small diameter expanded polytetrafluoroethylene (ePTFE) vascular grafts is platelet‐mediated thrombosis. We have designed a surface modification for ePTFE consisting of a self‐assembling fluorosurfactant polymer (FSP) bearing biologically active ligands, including adhesive peptides and polysaccharide moieties. The goal of this biomimetic construct is to improve graft hemocompatibility by promoting rapid surface endothelialization, whereas minimizing platelet adhesion. Here we present a direct comparison of platelet and endothelial cell (EC) adhesion to FSPs containing one of three cell‐adhesion peptides: cyclic Arg‐Gly‐Asp‐D‐Phe‐Glu (cRGD), cyclic *Cys‐Arg‐Arg‐Glu‐Thr‐Ala‐Trp‐Ala‐Cys* (cRRE, *denotes disulfide bond cyclization), linear Gly‐Arg‐Gly‐Asp‐Ser‐Pro‐Ala (RGD), or a polysaccharide moiety: oligomaltose (M‐7), later designed to prevent nonspecific protein adhesion. Measurements of soluble peptide‐integrin binding indicated that cRRE exhibits very low affinity for the αIIbβ3 platelet fibrinogen receptor. Static and dynamic adhesion of washed, activated platelets on FSP‐modified surfaces revealed that M‐7 and cRRE promote significantly less platelet adhesion compared to RGD and cRGD FSPs, whereas EC adhesion was similar on all peptide FSPs and minimal on M‐7 FSP. These results illustrate the potential for ligands presented in a FSP surface modification to selectively adhere ECs with limited platelet attachment. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2009
Fibroblast growth factor‐2‐apatite composite layers on titanium screw to reduce pin tract infection rate
Authors: Mutsuzaki Hirotaka , Ito Atsuo , Sakane Masataka , Sogo Yu , Oyane Ayako , Ochiai Naoyuki
Published: February 2008

Fibroblast growth factor‐2 (FGF‐2)‐apatite composite layers were formed on anodically oxidized titanium screws to improve bone‐screw interface strength and to reduce pin tract infection rate through enhanced skin tissue healing in external fixation. A calcium‐containing solution supplemented with FGF‐2, a phosphate‐containing solution, and a sodium bicarbonate solution were mixed at a Ca/P molar ratio of 2.0 to prepare a calcium phosphate solution supersaturated with respect to calcium phosphates. Screws were individually immersed in 10 mL of the calcium phosphate solution at 37°C for 2 days. Low‐crystalline apatite layers incorporating FGF‐2 were formed on the screw surface at FGF‐2 concentrations in the supersaturated calcium phosphate solution equal to or lower than 10 μg/mL. The amounts of FGF‐2 immobilized on the screws ranged from 2.3‐ to 2.4‐μg per screw. The immobilized FGF‐2 retained biological activity, as demonstrated by NIH3T3 cell proliferation. Titanium screws with the composite layer were percutaneously implanted into the bilateral proximal tibial metaphyses in rabbits for 4 weeks. The titanium screws with the composite layer formed at the optimum FGF‐2 concentration showed a significantly higher bone‐screw interface strength and a lower pin tract infection rate than those without the composite layer: the extraction torque and infection rates were respectively 0.230 ± 0.073 Nm and 43.8% for the screws with the composite layer, and 0.170 ± 0.056 Nm and 93.8% for those without the composite layer. Therefore, titanium screws with the FGF‐2‐apatite composite layer are useful for improving bone‐screw interface strength and infection resistance in external skeletal fixation. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
CYR61 is a novel gene associated with temperature‐dependent changes in fish metabolism as revealed by cDNA microarray analysis on a medaka Oryzias latipes cell line
Authors: Hirayama Makoto , Ahsan Md. Nazmul , Mitani Hiroshi , Watabe Shugo
Published: February 2008

A microarray comprising 3,514 cDNAs was constructed from a medaka EST library to elucidate the transcriptional responses associated with temperature shift from 25 to 15°C in a medaka cell line. Microarray analysis revealed that the mRNA levels of 313 clones were significantly different in at least one combination of different incubation periods up to 7 days at a given incubation temperature or between 25 and 15°C at a given incubation period (P < 0.05). These genes are known to be associated with various biological processes including morphogenesis, cell proliferation and response to stress. A number of genes encoding proteins which localize in extracellular areas were apparently up‐regulated at 15°C, whereas those localizing in intracellular areas were down‐regulated at this temperature. In addition, while a number of genes represented long‐term expression changes, only a few responded to short‐term inductions. A typical example was CYR61, a multifunctional matricellular signaling modulator, the mRNA levels of which increased after temperature shift from 25 to 15°C in 3 h, and then decreased rapidly to near the original level within 12 h. Another series of analyses by quantitative reverse transcription‐PCR revealed that the mRNA levels of CYR61 at 5°C were significantly higher even at 24 h after temperature shift compared to those of the cells successively maintained at 25°C. These analyses suggest that remodeling and reorganizing of extracellular structure of cells are important to offset the low temperature effect and CYR61 is considered to be a novel gene associated with temperature response in poikilotherms. J. Cell. Biochem. 104: 1297–1310, 2008. © 2008 Wiley‐Liss, Inc.
Activation of the ERK pathway in osteoblastic cells, role of gremlin and BMP‐2
Authors: Zanotti Stefano , Smerdel‐Ramoya Anna , Stadmeyer Lisa , Canalis Ernesto
Published: February 2008

Gremlin is a glycoprotein that binds and antagonizes the actions of bone morphogenetic proteins (BMPs) ‐2, ‐4, and ‐7. Gremlin appears to activate the extracellular regulated kinase (ERK) pathway in endothelial and tumor cells, and as a consequence to have direct cellular effects. To determine whether gremlin has direct effects in osteoblasts, independent of its BMP binding activity, we examined its effects in ST‐2 murine stromal cell lines and in primary cultures of murine calvarial osteoblasts. Gremlin did not activate Signaling mothers against decapentaplegic (Smad), and suppressed the BMP‐2 induced Smad 1/5/8 phosphorylation and the transactivation of the BMP/Smad reporter construct 12xSBE‐Oc‐pGL3, confirming its BMPs antagonizing activity. Neither gremlin nor BMP‐2 induced ERK 1/2 activation in ST‐2 cells or calvarial osteoblasts. Moreover, slight changes in culture conditions induced the phosphorylation of ERK independent from BMP or gremlin exposure. In conclusion, gremlin inhibits BMP‐2 signaling and activity, and does not have independent actions on ERK signaling in osteoblasts. Consequently, gremlin activity in osteoblasts can be attributed only to its BMP antagonizing effects. J. Cell. Biochem. 104: 1421–1426, 2008. © 2008 Wiley‐Liss, Inc.
p38/NF‐kB‐dependent expression of COX‐2 during differentiation and inflammatory response of chondrocytes
Authors: Ulivi Valentina , Giannoni Paolo , Gentili Chiara , Cancedda Ranieri , Descalzi Fiorella
Published: February 2008

Studying cartilage differentiation, we observed the emergence of inflammation‐related proteins suggesting that a common pathway was activated in cartilage differentiation and inflammation. In the present paper, we investigated the expression pathway of the inflammation‐related enzyme Cyclooxygenase‐2 (COX‐2) during differentiation and inflammatory response of the chondrocytic cell line MC615. Cells were cultured either as (i) proliferating prechondrogenic cells expressing type I collagen or (ii) differentiated hyperconfluent cells expressing Sox9 and type II collagen. The p38 and the NF‐kB pathways were investigated in standard conditions and after inflammatory agents treatment. NF‐kB was constitutively activated in differentiated cells. The activation level of NF‐kB in differentiated cells was comparable to the level in proliferating cells treated with the inflammatory agent LPS. In both cases, p65 was bound to the NF‐kB consensus sequence of COX‐2 promoter. p38, constitutively activated in differentiated cells, was activated in proliferating cells by treatment with LPS or IL‐1α. In stimulated proliferating cells the two pathways are connected since addition of the p38‐specific inhibitor SB203580 inhibited p38 activation, significantly reduced NF‐kB activation and repressed COX‐2 synthesis indicating that p38 is upstream NF‐kB activation and COX‐2 synthesis. In differentiated cells, the treatment with the inflammatory agent neither enhance NF‐kB activation, nor synthesis of COX‐2 while the addition of SB203580 neither repressed activation of p38, nor COX‐2 synthesis, suggesting a constitutive activation of a p38/NF‐kB/COX2 pathway. Our data indicate that in chondrocytes, COX‐2 is expressed via p38 activation/NF‐kB recruitment during both differentiation and inflammatory response. J. Cell. Biochem. 104: 1393–1406, 2008. © 2008 Wiley‐Liss, Inc.
Additional MDA‐MB‐231 breast cancer cell matrix metalloproteinases promote invasiveness
Authors: Hegedüs Luca , Cho Hyojin , Xie Xian , Eliceiri George L.
Published: February 2008

We are interested in two aspects of a given type of metastatic breast cancer: which potentially cancer‐relevant genes are expressed and which factors determine invasiveness. Using reverse transcription real‐time PCR, we detected gene expression of 26 matrix metalloproteinases (MMPs) in MDA‐MB‐231 breast cancer cells, including those of MMP‐12, MMP‐16 variant 2, MMP‐19, MMP‐20, MMP‐21, MMP‐23, MMP‐24, MMP‐25, MMP‐25 variant 2, MMP‐L1, MMP‐26, MMP‐27, and MMP‐28, in contrast to the 13 MMPs detected until now in these cells. We found that MMP genes are expressed at widely different levels in these cells, over five orders of magnitude. After individual siRNA‐induced depletions, we found that six additional species of cancer cell MMPs promote invasiveness in MDA‐MB‐231 cells: MMP‐3, MMP‐11, MMP‐12, MMP‐17, MMP‐19, and MMP‐23, thus raising the total to 12 endogenous MMPs which do so in these cells. The data support the conclusion that some cancer cell MMPs, although expressed at low levels, are needed for cancer trait in MDA‐MB‐231 cells, and that several endogenous MMPs play non‐redundant roles in this process. The mRNA level of MMP‐11, but not of other MMPs, rose substantially following individual siRNA‐targeted depletion of cancer cell MMP‐17 mRNA, while no MMP mRNA increased appreciably after degradation of other MMP mRNAs. This supports the conclusion that MMP‐17 may be a member of an intracellular signaling pathway which downregulates MMP‐11 mRNA. J. Cell. Physiol. 216: 480–485, 2008. © 2008 Wiley‐Liss, Inc.
Contrast‐enhanced sonographic characteristics of neovascularization in carotid atherosclerotic plaques
Authors: Huang Pin‐tong , Huang Fu‐guang , Zou Chun‐peng , Sun Hai‐yan , Tian Xin‐qiao , Yang Yan , Tang Ji‐fei , Yang Peng‐lin , Wang Xiao‐tong
Published: February 2008

Purpose.

To evaluate neovascularization within carotid atherosclerotic plaques with contrast‐enhanced sonography.

Methods.

We used contrast‐enhanced sonography to examine 63 patients with carotid atherosclerotic plaques. The features of neovascularization within the plaques were analyzed and correlated with plaque size and echogenicity.

Results.

There were 81 atherosclerotic plaques, 62 of which (43 soft and 19 mixed) enhanced after injection of a contrast agent. The enhancement occurred from the carotid wall to the center of the plaque with a short‐line pattern in 36 plaques, whereas 26 plaques enhanced from both the carotid wall and the carotid lumen, with a sparse spot pattern. The arrival time of contrast was shorter (p < 0.001) and time to peak was longer (p < 0.001) in the plaques than in the carotid lumen. Time to peak was shorter, whereas enhanced intensity was greater in soft plaques than in mixed plaques (p < 0.01 and p < 0.05, respectively). Among the 19 unenhanced plaques, 6 were hard, 3 were calcified, 3 were soft, and 7 were mixed. The thickness of the unenhanced plaques was <2.4 mm.

Conclusion.

Contrast‐enhanced sonography allows the noninvasive, dynamic evaluation of neovascularization within carotid plaques, and the presence of neovascularization may correlate with plaque morphology. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
Effect of season on thermoregulation, metabolism and ventilation of the southern brown bandicoot Isoodon obesulus (Marsupialia: Peramelidae)
Authors: Larcombe Alexander Neil , Withers Philip Carew
Published: February 2008

Seasonal variation in various thermoregulatory, metabolic and ventilatory parameters was examined for southern brown bandicoots (Isoodon obesulus fusciventer) from a Mediterranean climate near Perth, Western Australia. There was significant seasonal variation over the four annual seasons at thermoneutrality (Ta=30°C) in body temperature, oxygen consumption, carbon dioxide production, respiratory exchange ratio, total evaporative water loss, wet and dry thermal conductance and tidal volume but not mass, ventilatory frequency, minute volume or oxygen extraction efficiency. Only carbon dioxide production and respiratory exchange ratio showed an annual pattern that was significantly related to season, with both being significantly higher in winter, presumably as a result of greater and higher quality food availability. J. Exp. Zool. 309A:175–183, 2008. © 2008 Wiley‐Liss, Inc.
Strategy for improved analysis of peptides by surface‐enhanced Raman spectroscopy (SERS) involving positively charged nanoparticles
Authors: Ngola Sarah M. , Zhang Jingwu , Mitchell Breeana L. , Sundararajan Narayan
Published: February 2008

A strategy for improved surface‐enhanced Raman spectroscopy (SERS) measurements that extends the variety of analytes accessible to SERS analysis is developed. The strategy involves inducing aggregation by mixing positively charged nanoparticles which form SERS‐active clusters when mixed with negatively charged silver nanoparticles fabricated using the Lee–Meisel process. To make positively charged nanoparticles, silver nanoparticles using the traditional Lee–Meisel process are fabricated and coated with a thin layer of silica and the silica modified with silane chemistry. Analytes with a significant amount of negative charge exhibit strong Raman bands when the strategy using these fabricated, positively charged nanoparticles for inducing cluster formation is used, enabling their detection and analysis. We envision the use of positively charged nanoparticles in cluster formation for expanding the range of analytes that can be detected using SERS and hence the range of applications SERS can play a role in. Copyright © 2008 John Wiley & Sons, Ltd.
Correlations between Raman parameters and elemental composition in lead and lead alkali silicate glasses
Authors: Robinet Laurianne , Bouquillon Anne , Hartwig Jean
Published: February 2008

This article examines the influence of the composition on the Raman spectra of lead silicate glass. Modern and historic lead alkali glasses and high‐lead glazed ceramics were analysed complementarily by Raman spectrometry and elemental techniques, either electron microprobe, proton induced X‐ray emission (PIXE) or scanning electron microscope with energy dispersive spectrometry (SEM‐EDS). The results showed that lead alkali silicate and high‐lead silicate glasses can be easily distinguished from their Raman spectra profile. In lead alkali silicate glasses, continuous variations were observed in the spectra with the compositional change. In particular, the position of the intense peak around 1070 cm−1 was linearly correlated to the lead content in the glass. A unique decomposition model was developed for the spectra of lead alkali silicate glasses. From the combination of the Raman and elemental analyses, correlations were established between the spectral components and the composition. These correlations permitted to interpret the spectra and access additional compositional information, such as the lead content from area ratio A990/A900–1150, the total alkali + alkaline‐earth content from the area ratio A1100/A900–1150 or the silica content from the area ratio A1150/A900–1150. In lead silicate glass containing over 25 mol% PbO, the compositional variation induced no variation in the SiO4 network region of the Raman spectra [150–1350 cm−1], therefore no correlations and compositional information could be gained from the glass spectra in this range of composition. This new development of Raman spectroscopy for the analyses of glass will be very valuable for museums to not only access compositional information non‐destructively but also to understand the structural changes involved with their alteration. Copyright © 2008 John Wiley & Sons, Ltd.
In situ Raman study of mineral phases formed as by‐products in a rotary kiln for clinker production
Authors: Gastaldi D. , Boccaleri E. , Canonico F.
Published: February 2008

Portland clinker production consists essentially in the burning of material with defined composition in a rotary kiln at temperatures around 1450 °C. The main fuel used in this process is coal, even though in the last few years the use of alternative fuels has been increasing. Four main minerals are formed, namely, tricalcium and dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. Along with these main phases, variations in burning conditions of fuels or in the local composition of raw materials can lead to the formation of relatively high amounts of secondary by‐products, which can negatively affect the quality of the final material. Characterization of these by‐products allows not only optimization of the process of clinker production but also the design of special refractory materials for the wall of kilns and preheaters. Being found as particles included in (or alternating to) a hard solid clinker matrix, a detailed characterization of these extra phases could be achieved only via microscopic techniques. In this work, micro‐Raman spectroscopy has been successfully tested as a highly selective method for characterization and localization of included minerals that formed as overlapped crusts deposited on the internal wall of a conventional rotary kiln for cement production, without any manipulation of the sample. Understanding the chronological order of deposition of these overlapped layers is extremely important, as it is the only way to go back up to the production process and to individuate the problem. Copyright © 2008 John Wiley & Sons, Ltd.
Coherent anti‐stokes Raman spectroscopy investigation of collisional broadening of the hydrogen Q‐branch transitions by water at high temperatures
Authors: Vereschagin K. A. , Vereschagin A. K. , Smirnov V. V. , Stel'makh O. M. , Fabelinsky V. I. , Clauss W. , Oschwald M.
Published: February 2008

By means of CARS interferometric line shape spectroscopy, the temperature dependences of the broadening coefficients for several Q‐branch lines of hydrogen molecules under collisions with water molecules were determined in the temperature range 2100 < T < 3500 K. Copyright © 2008 John Wiley & Sons, Ltd.
Gastrointestinal stromal tumors and leiomyosarcomas
Authors: Katz Steven C. , DeMatteo Ronald P.
Published: February 2008

Only recently has gastrointestinal stromal tumor (GIST) been recognized as the most frequent GI mesenchymal neoplasm. Prior to the use of KIT staining, most GI stromal tumors were identified as leiomyosarcoma (LMS). For primary GIST, surgery remains the principal treatment and adjuvant imatinib may improve outcomes. Multimodality therapy may also be effective in patients with metastatic GIST. In this review, we summarize the epidemiology, clinicopathologic features, natural history, and clinical management of LMS and GIST. J. Surg. Oncol. 2008;97:350–359. © 2008 Wiley‐Liss, Inc.
Diagnosis and management of pleomorphic sarcomas (so‐called “MFH”) in adults
Authors: Nascimento Alessandra F. , Raut Chandrajit P.
Published: February 2008

The existence of “malignant fibrous histiocytoma” (“MFH”) as a distinct entity is controversial. Previously accepted as the most common sarcoma affecting adults, it is now known to comprise a heterogeneous group of tumors without a specific known line of differentiation. Reclassification of many tumors in this group afforded better prognostication, but traditional treatments still apply. Pleomorphic soft tissue tumors for which a line of differentiation is debatable are presently categorized as undifferentiated pleomorphic sarcoma. J. Surg. Oncol. 2008;97:330–339. © 2008 Wiley‐Liss, Inc.
Diagnosis and management of synovial sarcoma
Authors: Eilber Fritz C. , Dry Sarah M.
Published: February 2008

Synovial sarcoma accounts about 9% of soft tissue sarcomas, most commonly develops in the extremity of young adults, is considered high grade and contains a characteristic translocation (X;18;p11;q11). While surgery and radiation therapy have achieved excellent local control, distant metastasis remains the principal problem limiting survival. Although ifosfamide based chemotherapy has been associated with an improved survival in patients with synovial sarcoma, the search for less toxic and more targeted systemic therapies is ongoing. J. Surg. Oncol. 2008;97:314–320. © 2008 Wiley‐Liss, Inc.
Diagnosis and management of lipomatous tumors
Authors: Dalal Kimberly Moore , Antonescu Cristina R. , Singer Samuel
Published: February 2008

Lipomatous tumors range from benign lipomas to high‐grade liposarcomas. Liposarcomas are classified into five histologic subtypes: well‐differentiated, dedifferentiated, myxoid, round cell, and pleomorphic, which differ in outcomes and patterns of recurrence. Surgical resection is the mainstay of curative treatment; however, large, high grade liposarcomas may benefit from multimodality treatment with chemotherapy and radiation. A histologic‐subtype specific nomogram provides accurate survival predictions. Prospective randomized clinical trials will continue to improve our care of patients with liposarcoma. J. Surg. Oncol. 2008;97:298–313. © 2008 Wiley‐Liss, Inc.
Expression of P53, P27 and KI‐67 in colorectal cancer patients of various ethnic origins: Clinical and tissue microarray based analysis
Authors: Cohen Tzeela , Prus Diana , Shia Jinru , Abu‐Wasel Bassam , Pinto Meir G. , Freund Herbert R. , Stojadinovic Alexander , Grakov Anna , Peretz Tamar , Nissan Aviram
Published: February 2008

Background

This study was conducted to determine survival according to the expression of molecular markers in colorectal cancer (CRC) patients of various ethnic origins.

Methods

Resection of primary tumor was conducted on 171 patients with CRC. Corresponding archived paraffin‐embedded blocks were retrieved and tissue microarray (TMA) constructed. Immunohistochemical staining of the TMA for p53, p27 and Ki‐67 was quantified by two independent pathologists. Survival was analyzed using the Kaplan–Meier product limit method.

Results

With a median follow‐up of 65 months, 56 patients (32.7%) died of disease. AJCC stage correlated with disease‐free (DFS, P < 0.0001) and overall survival (OS, P < 0.0001). IHC staining was positive for Ki‐67 in 77.4%, p53 in 55.8% and p27 in 54.2% of patients. Primary tumor marker expression did not correlate with DFS or OS. The 5‐year DFS for Ashkenazi Jews was 75%, significantly higher than Sephardic Jews (SJ) 64% and Palestinian Arabs (PA) 38%, P = 0.001.

Conclusions

Ethnicity among Ashkenazi and SJ and PA appears to have a significant impact on disease outcome in patients with CRC patients, while primary tumor expression of p53, p27 and Ki‐67 was unrelated to disease outcome. J. Surg. Oncol. 2008;97:416–422. Published 2008 Wiley‐Liss, Inc.
Macromol. Biosci. 2/2008
Authors: Spasova Maria , Paneva Dilyana , Manolova Nevena , Radenkov Philip , Rashkov Iliya
Published: February 2008

Cover:Non‐woven textiles with combined antibacterial and haemostatic activity have been obtained by coating of electrospun poly(L‐lactide) mats with chitosan. The mats are promising candidates for wound healing applications enabling rapid cessation of bleeding and regeneration of injured tissue. Further details can be found in the article by M. Spasova, D. Paneva, N. Manolova, P. Radenkov, and I. Rashkov* on page 153.
Qualitative model of concrete acidification due to cathodic protection
Authors: Peelen W. H. A. , Polder R. B. , Redaelli E. , Bertolini L.
Published: February 2008

In this paper a mathematical description and numerical implementation for ion transport in concrete due to current passage is developed, in which the heterogeneous equilibrium between Ca2+, OH− and the solid Ca(OH)2 is incorporated. The description is based on the Nernst–Planck equation for ion transport, and reaction terms for the dissolution/precipitation of Ca(OH)2. This description was implemented in the finite element package Comsol Multiphysics. In this way Ca(OH)2 depletion in a zone at a CP anode adjacent to a bulk of concrete with Ca(OH)2 could be modelled in one calculation. Drawback of this model is that the kinetic parameters in the reaction terms are not known, and must be chosen high to ensure the dissolution of Ca(OH)2 to be in equilibrium. This proved numerically challenging and sometimes caused long calculation times.

The growth rate of the zone without solid depends on the current density applied, concrete cover, the pore liquid composition and the diffusion constants of Ca2+ and OH−. This rate must be evaluated numerically. This qualitative model of anode acidification shows no participation of Na+; therefore transport properties of this ion do not affect the acidification rate of concrete. The same would hold for any other ion included in the model, which is not involved in electrochemical or chemical reactions.
Galvanised constructional elements in contact with prestressing steel tendons
Authors: Mietz J. , Burkert A. , Lehmann J. , Burkert A. , Eich G.
Published: February 2008

In order to clarify under which practical conditions real risks for hydrogen‐induced stress corrosion cracking of prestressing steels exist laboratory investigations in aqueous solutions and concrete as well as tests with stressed prestressing steels were carried out. While different distances between steel and zinc (cathode and anode) showed only a negligible influence on the polarisation of the steel a significant dependence on the area ratio steel/zinc was observed. A critical area ratio of 10:1 can be defined above which polarisation of the steel to hydrogen evolution potentials is unlikely. The results obtained in the laboratory concerning the critical area ratio were confirmed by on‐site investigations in a precasting plant. Exposure tests with hydrogen loading did not lead to fractures during the testing time for approved prestressing steels. The characteristic mechanical values determined immediately after the hydrogen loading tests did not show significant changes. Thus, an indirect contact between prestressing steels and galvanised elements can be estimated as uncritical. But a direct contact has to be excluded by compliance with DIN 1045‐1, i.e minimal distance of 2 cm between prestressing steel and galvanised elements.
Stainless steel in concrete structures and in the fastening technique
Authors: Nürnberger U. , Wu Y.
Published: February 2008

This paper summarises the state of the art in the application of stainless steel in concrete structures as well as in the fastening technique. Fabrication and application of stainless steel in civil engineering has been undergoing development for many years. Today this material is available in different alloy compositions and has an excellent long‐time resistivity in natural environments and in contact with wet construction materials, which offer a technically attractive and also economical approach for civil engineering, primarily for corrosion endangered bearing construction elements. The higher initial cost of using stainless steel can be justified on the basis that the increase in total project cost is small and is easily overtaken by the benefits of lower maintenance and repair costs. Actually stainless steel has been used in reinforced concrete and in fastening techniques for many years. The current concerns of research is the application of high‐strength stainless steel in prestressed concrete structures.
Advanced models for erosion corrosion and its mitigation
Authors: Schmitt G. , Bakalli M.
Published: February 2008

Erosion corrosion, i.e., flow‐induced localized corrosion (FILC) is initiated when flow dynamic forces surpass the fracture energy of protective layers or scales on metals. With a new model the maximum interaction energies between flowing media and solid walls can be quantified in terms of “freak” energy densities created during singular events (freak events) of perpendicular impacts by near‐wall microturbulence elements. The freak energy densities are in the megaPascal range and match well in the order of magnitude with fracture energies of protective layers and can be estimated from Wavelet diagnostics of electrochemical current noise measured at microelectrodes under mass transport controlled conditions. This solves the problem that wall shear stresses, generally used to quantify critical flow intensities for FILC initiation, range several orders of magnitude (Pa range) below the fracture energies of protective layers. The new advanced model allows for the first time to quantify the maximum fluid dynamic forces exerted on solid walls under different turbulent and disturbed flow conditions (one‐phase liquid flow on jet impinged surfaces and on coupons in rotated cages, surfaces impacted by slug flow and gas‐pulsed impinging jets). Drag reducing additives were shown to reduce freak energy densities to values significantly below fracture energies of protective layers and hence inhibit initiation of FILC. The onset of FILC can be monitored online with the newly developed CoulCount method, an easy‐to‐use, non‐invasive diagnostic tool which evaluates electrochemical current noise between jet impinged electrode pairs made from the metals to be tested.
The change of dielectric properties of barrier coatings during the initial state of immersion
Authors: Strunz W. , Schiller C. A. , Vogelsang J.
Published: February 2008

The initial state of immersion of seven commercially available barrier coatings was monitored using electrochemical impedance spectroscopy (EIS). Within the first spectra, a fast change of state can be detected at low frequencies. This non‐stationarity can be eliminated with an evaluation procedure, known as the Z‐HIT algorithm, resulting in causal spectra which can be interpreted reliably and accurately. The spectra of the coatings can be well modeled by a parallel combination of a capacity and a two step continuous time random walk (CTRW‐2) as a relaxation element. The capacity represents the pure dielectric properties of the coating material which are not affected by the penetrating electrolyte solution. This part of the evaluated coating capacity remains constant during the soaking. In contrast, the parameters of the CTRW‐2 change during water uptake and can be attributed to pores and free sites within the coating material. This separation into parts which are affected by the penetrating solvent and parts which can be described by an ideal dielectric material reflects the inhomogeneous nature of the coatings under test.

In the entire measured frequency range the change of the dielectric properties of the investigated systems can be modeled by the same equivalent circuit which was used formerly to interpret impedance spectra of barrier coatings in the saturated state, requiring four to five adjustable parameters for simulating the experimental data.
Novel repair method for technical enamels based on sol–gel and sol‐dispersion coatings
Authors: Benfer S. , Fürbeth W. , Schütze M.
Published: February 2008

The aim of the work presented here is the development of a novel repair method for technical enamels by using chemical nanotechnology. Good adhesion of coatings requires good wettability of the substrate by the repair solution. This was achieved by different pre‐treatments of the steel substrates. Low sintering temperatures of the coatings can be ensured by the use of nanoparticle‐based systems. Based on liquid metal alkoxides, a colloidal alumina sol and metal salts homogeneous sols with up to seven enamel compounds were prepared. The sols were brush coated onto plain and partly enamelled steel substrates and sintered in a furnace, by inductive heating or an IR emitter. Thin (single layer ≪ 1µm) crack‐free layers were obtained on nearly all substrates independent of the sintering conditions investigated. The local sintering methods (IR emitter, inductive heating) allow to produce multiple coating systems in short times. Electrochemical impedance spectroscopy (EIS) provides evidence of the protective effect of these layers compared to the bare substrate, but as a result of their chemical composition the layers are not stable in the electrolytic environment for longer times. The thickness of such multiple coatings (20 layers, ≈ 8 µm) is still small compared to that of a technical enamel. Therefore, sol dispersion systems containing powder particles and sol components are applied on top of the sol–gel layers to increase the thickness of the sintered layers.
Influence of the chromate content in cement on the corrosion behaviour of steel in concrete
Authors: Schieß P. , Mayer T. F. , Osterminski K.
Published: February 2008

Chromate, which is known to be an effective corrosion inhibitor in various applications, is contained in cement as a trace element. So far its influence on the corrosion of steel in contact with concrete has not been investigated. However, as the introduction of chromate‐reduced cements has coincided with an increase in corrosion phenomena occurring on steel moulds in precast concrete plants, the question has been raised whether chromate might as well have an influence on the corrosion of reinforcement in hardened concrete.

Against this background different experiments for examining the influence of chromate on the corrosion behaviour of steel in synthetic pore solution, fresh and hardened concrete have been carried out. The results showed that the reduction of chromate has different consequences for the time periods of fresh and hardened concrete. During early hydration within the first 12–24 h the natural chloride content of the concrete constituents may be sufficient to start corrosion. Experiments yielded a higher corrosion risk for steel embedded in chromate‐reduced concrete. This first stage is followed by a repassivation as pH rises and chlorides are bound in the course of cement hydration. In hardened concrete no significant influence of the chromate content in the cement on the corrosion behaviour could be found.
Long‐term durability of electrochemical chloride extraction
Authors: Elsener B.
Published: February 2008

This paper presents field data from one of the first well‐documented reinforced concrete structures that has been rehabilitated with electrochemical chloride extraction (ECE) in the year 1989. The results of half‐cell potential mapping measured 1, 5 and nearly 20 years after the ECE treatment show that the reinforcement was completely repassivated after the ECE treatment and remained in fully passive condition. Regarding the efficiency of the ECE treatment an intermittent (current on–off) is beneficial. The question of repassivation of pre‐corroded reinforcement is discussed. According to this and other results from field applications the ECE treatment is effective and – if further chloride ingress is avoided – also durable. For economical reasons it is recommended to apply the non‐destructive ECE treatment in an early state, before delaminations or spalling has occurred.
A benchmarking test for surface treatment products for zinc die cast
Authors: Feser R. , Schulz Ch.
Published: February 2008

Corrosion protection of zinc surfaces was successfully done in the past by chromate conversion layers. To reduce the amount of Cr(VI) products in the environment substitution processes have been developed. For the zinc industry it was a question whether surface treatment products are on the market which can substitute the conventional chromating process. A benchmarking test should be performed to show how good the Cr(VI) free products are in comparison to the state of the art process. Several corrosion tests have been performed to show the corrosion behaviour of treated zinc die cast products in comparison to Cr(VI) treated and plain surfaces. Additionally electrochemical measurements have been performed to discriminate further between the products. Especially CoulCount measurements show clearly the protection capability of the various surface treatments. No one of the tested products shows the same good behaviour like Cr(VI) treated products, but the performance of several products looks not bad and has to be proofed further under real service conditions.
A trend toward abrasive nano finishing of plane surfaces with magnetic field energy
Authors: Vahdati M. , Shokuhfar A.
Published: February 2008

In new developed parts, roughness has become an effective parameter and influences the performance of the entire system. Manufacturing of parts with fine surface finish have been a target for many advanced industries. Sometimes, it is difficult to reach highly polished surface quality by conventional methods. One of the newly introduced methods for obtaining fine finished surfaces is nano‐scale finishing with abrasive particles in magnetic fields. It is a relatively new finishing process that can be used to produce efficiently shiny surface quality for certain parts [1]. In this process, the cutting movement is provided by the magnetic field energy of permanent or electric poles. Magnetic abrasive particles (MAPs) are used to remove chips, and polish the work‐piece surface [2, 3]. The work‐piece is in the shape of a flat plane. An apparatus has been designed and made for machining the upper face of the plane. Nd‐Fe‐B magnets are used to establish the magnetic field. An NC machine is applied to create the rotational movement of MAPs in the horizontal plane and maintain the vertical position accurately. Various experiments have been designed to specify the machining characteristics of the MAF process. In these experiments different effective conditions are determined. Permanent magnets with 1.2 T magnetic flux density are used as magnetic poles. Homogeneous mechanical mixture of abrasive powder (Silicon Carbide) and ferromagnetic iron particles are used as the MAPs. The experimental setup was designed for finishing the aluminium alloy AA–6061. Test results indicated that the finishing parameters affect the material removal rate (MRR) and surface roughness.
An optimization technique using the characteristics of genetic algorithm
Authors: Kim G.‐H. , Lee Y.‐S.
Published: February 2008

Optimization problems could happen often in discrete or discontinuous search space. Therefore, the traditional gradient‐based methods are not able to apply to this kind of problems. The discrete design variables are considered reasonably and the heuristic techniques are generally adopted to solve this problem, and the genetic algorithm based on stochastic search technique is one of these. The genetic algorithm method with discrete variables can be applied to structural optimization problems, such as composite laminated structures or trusses. However, the discrete optimization adopted in genetic algorithm gives rise to a troublesome task that is a mapping between each strings and discrete variables. And also, its solution quality could be restricted in some cases. In this study, a technique using the genetic algorithm characteristics is developed to utilize continuous design variables instead of discrete design variables in discontinuous solution spaces. Additionally, the proposed algorithm, which is manipulating a fitness function artificially, is applied to example problems and its results are compared with the general discrete genetic algorithm. The example problems are to optimize support positions of an unstable structure with discontinuous solution spaces.
Ascertaining late‐life depressive symptoms in Europe: an evaluation of the survey version of the EURO‐D scale in 10 nations. The SHARE project
Authors: Castro‐Costa Erico , Dewey Michael , Stewart Robert , Banerjee Sube , Huppert Felicia , Mendonca‐Lima Carlos , Bula Christophe , Reisches Friedel , Wancata Johannes , Ritchie Karen , Tsolaki Magda , Mateos Raimundo , Prince Martin
Published: February 2008

The reported prevalence of late‐life depressive symptoms varies widely between studies, a finding that might be attributed to cultural as well as methodological factors. The EURO‐D scale was developed to allow valid comparison of prevalence and risk associations between European countries. This study used Confirmatory Factor Analysis (CFA) and Rasch models to assess whether the goal of measurement invariance had been achieved; using EURO‐D scale data collected in 10 European countries as part of the Survey of Health, Ageing and Retirement in Europe (SHARE) (n = 22,777). The results suggested a two‐factor solution (Affective Suffering and Motivation) after Principal Component Analysis (PCA) in 9 of the 10 countries. With CFA, in all countries, the two‐factor solution had better overall goodness‐of‐fit than the one‐factor solution. However, only the Affective Suffering subscale was equivalent across countries, while the Motivation subscale was not. The Rasch model indicated that the EURO‐D was a hierarchical scale. While the calibration pattern was similar across countries, between countries agreement in item calibrations was stronger for the items loading on the affective suffering than the motivation factor. In conclusion, there is evidence to support the EURO‐D as either a uni‐dimensional or bi‐dimensional scale measure of depressive symptoms in late‐life across European countries. The Affective Suffering sub‐component had more robust cross‐cultural validity than the Motivation sub‐component. Copyright © 2008 John Wiley & Sons, Ltd.
Psychometric properties of the Chinese version of the Swanson, Nolan, and Pelham, version IV scale – parent form
Authors: Gau Susan Shur‐Fen , Shang Chi‐Yung , Liu Shih‐Kai , Lin Chien‐Ho , Swanson James M. , Liu Yu‐Chih , Tu Chang‐Ling
Published: February 2008

This study aimed to establish the psychometric properties of parent ratings on the Chinese version of the Swanson, Nolan, and Pelham IV scale (SNAP‐IV) in a school‐based sample of 3534 students in grades 1 to 8 from two cities and two suburbs in Taiwan and 189 children diagnosed with attention deficit/hyperactivity disorder (ADHD) (aged 6 to 15) consecutively recruited from a medical center in Taipei. Parents completed the Chinese versions of the SNAP‐IV, Strengths and Difficulties Questionnaire, and Child Behavior Checklist. The Chinese SNAP‐IV demonstrated similar three factor structure (Inattention, Hyperactivity/Impulsivity, and Oppositional) as its English version, and satisfactory test–retest reliability (intraclass correlation = 0.59∼0.72), internal consistency (alpha = 0.88∼0.90), concurrent validity (Pearson correlations = 0.56∼0.72), and discriminant validity. Boys scored higher than girls across the eight school grade levels. The SNAP‐IV clearly distinguished children with ADHD from school‐based participants. Comorbidity with oppositional defiant disorder/conduct disorder predicted higher SNAP‐IV scores among children with ADHD. Our findings suggest that the Chinese SNAP‐IV is a reliable and valid instrument for rating ADHD‐related symptoms in both clinical and community settings in Taiwan. Copyright © 2008 John Wiley & Sons, Ltd.
Exploring daily variations of drinking in the Swiss general population. A growth curve analysis
Authors: Heeb Jean‐Luc , Gmel Gerhard , Rehm Jürgen , Mohler‐Kuo Meichun
Published: February 2008

This study aims to address the underlying trajectories of weekly individual drinking patterns by growth models and to relate differences in drinking patterns to socio‐demographic and drinking characteristics of respondents. Data came from a two‐stage stratified random subsample of 747 persons aged 15 years or more from a Swiss study on alcohol consumption using a within‐subject design conducted between March 1999 and July 1999. Beverage specific assessment of daily alcohol consumption was obtained by a weekly drinking diary and other characteristics via telephone interviews. The diary had to be filled out on seven consecutive days. The growth models accounted for up to 37.6% of the initial error variance and provided evidence for two distinct, negatively correlated underlying trajectories of drinking patterns. The first trajectory described an increase in consumption from Monday to Sunday. The second trajectory was about a specific weekend consumption culminating on Saturday with a significantly higher growth rate among young people and heavy episodic drinkers than in other subgroups. Therefore, young and heavy episodic drinkers may be exposed to sudden adverse consequences of alcohol consumption during the weekend. Prevention efforts which are targeted to this subgroup should take its specific drinking pattern into account. Copyright © 2008 John Wiley & Sons, Ltd.
Meta‐analyses of the incidence and prevalence of schizophrenia: conceptual and methodological issues
Authors: Saha Sukanta , Chant David , Mcgrath John
Published: February 2008

While meta‐analytic techniques are routine in the synthesis of data from randomized controlled trials, there are no clear guidelines on how best to summarize frequency data such as incidence and prevalence estimates. Based on data from two recent systematic reviews of the incidence and prevalence of schizophrenia, this paper explores some of the conceptual and methodological issues related to the meta‐analyses of frequency estimates in epidemiology. Because variations in the incidence and prevalence of disorders such as schizophrenia can be informative, there is a case against collapsing data into one pooled estimate. Variations in frequency estimates can be displayed graphically, or summarized with quantiles around measures of central tendency. If pooled estimated are of interest, then researchers need to be aware that studies based on large samples will leverage greater weight on the pooled value. Based on systematic reviews of the incidence and prevalence of schizophrenia, we explore if these and related issues are of practical concern. When used with appropriate caution, meta‐analysis can complement the synthesis of frequency data in epidemiology; however, researchers interested in variation should not rely on meta‐analysis alone. Copyright © 2008 John Wiley & Sons, Ltd.