bluuebunny/crossref_metadata_2025 huggingface dataset:
Generation and Reactivity of 1,2‐Cyclohexadiene under Mild Reaction Conditions (Eur. J. Org. Chem. 32/2009)
Authors: Quintana Iago , Peña Diego , Pérez Dolores , Guitián Enrique
Published: October 2009

The cover picture shows a cyclohexallene‐based starry night over the cathedral of Santiago de Compostela in northwest Spain. 1,2‐Cyclohexadiene is a highly reactive cyclic allene that is usually generated by the use of strong bases or highly nucleophilic reagents, and this limits its scope. Herein we described an improved method to generate this molecule by fluoride‐induced β‐elimination of the corresponding 6‐(trimethylsilyl)cyclohexenyl triflate. This method allows the generation of this strained cyclic allene under mild reaction conditions and with higher efficiency than classical approaches, as demonstrated by trapping experiments based on cycloaddition reactions. Details are discussed in the article by D. Peña et al. on p. 5519 ff.
Gender differences in distributive negotiation: When in the negotiation process do the differences occur?
Authors: Miles Edward W.
Published: October 2009

This study tested whether the degree of association among aspiration level, intended opening offer, actual first offer, actual counter‐offer, and final agreement was moderated by negotiator gender. Results show that gender does moderate the association between the predictor variable of intended opening offer and the criterion variable of actual first offer and the relationship between intended opening offer and actual counter‐offer. Interesting, this latter association was statistically non‐significant for women and statistically significant for men. These results suggest that gender differences disadvantaging women seem to manifest with the actual first offer and the actual counter‐offer. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of Cesium on Nickel Hexacyanoferrate‐Aluminum Oxide Modified Electrodes
Authors: Delgado Luis , Carrero Hermes , Fernández Lenys
Published: October 2009

This report investigates the electrochemical behavior of hexacyanoferrate casted on Ni‐Al2O3 modified electrodes and the preconcentration and detection of cesium ions on such films. It also studies the morphology and the composition of these surfaces. The film was grown on a glassy carbon (GC) surface. Five consecutive voltammetric cycles applied within 0.0 V and −1.6 V at a scan rate of 10 mV/s were enough to cast the film. Scanning electron microscopy (SEM) analyses showed a homogeneous, porous but broken surface of the film. Its composition was studied by X‐ray diffraction (XRD). The presence of NiHCFe was confirmed by Fourier transformed infrared spectroscopy (FT‐IR). The Cs+ preconcentration from diluted solutions was accomplished in 90 s, under a negative potential of −0.20 V applied to the modified working electrode. The detection of cesium has a good sensitivity and a wide linear interval (10−8 and 10−12 mol L−1). Even so, the limit of detection calculated was extremely low (2×10−16 mol L−1), cesium concentrations lower than 10−12 mol L−1 gave signals with no analytical significance. However, to our knowledge, this is the lowest level of cesium ever detected by an electroanalytical technique.
Simultaneous Determination of Tyrosine and Histidine by Differential Pulse Cathodic Stripping Voltammetry Using H‐point Standard Addition Method in Tap and Seawater
Authors: Shahlaei Mohsen , Gholivand Mohammad Bagher , Pourhossein Alireza
Published: October 2009

H‐point standard addition method (HPSAM) has been applied for simultaneous determination of tyrosine and histidine in trace levels using copper ions by adsorptive cathodic stripping voltammetry. The amino acids‐Cu(II) complexes were accumulated onto the surface of a hanging mercury drop electrode for 40 s. The reduction peaks of preconcentrated complexes were used for simultaneous determination of amino acids in the range 8.0–180 and 30–1100 nM for tyrosine and histidine respectively. The effect of various parameters such as pH, concentration of copper, accumulation time and scan rate on the selectivity were studied. Under the optimized conditions the method was successfully applied for determination of tyrosine and histidine in synthetic and real samples.
Analytical fragility analysis of southern Illinois wall pier supported highway bridges
Authors: Bignell John , LaFave James
Published: October 2009

An analytical fragility analysis was conducted in order to characterize the seismic vulnerability of existing southern Illinois wall pier supported highway bridges to potential earthquakes. To perform this fragility analysis, a detailed inventory survey was first taken of the wall pier bridges identified in an earlier random sampling of southern Illinois priority emergency route bridges. From the survey three types of wall pier bridges were identified. Of those identified, hammerhead and regular wall pier supported bridges represented nearly 90% of the population. Incorporating structural variations determined from the random sample survey, nearly 100 three‐dimensional nonlinear finite element models were constructed. Each model was subjected to a randomly assigned synthetic earthquake representative of those that could potentially occur within the region. From these analyses, a series of wall pier supported bridge fragility curves were produced. In addition, a liquefaction fragility analysis was conducted in order to characterize the seismic vulnerability of southern Illinois wall pier supported highway bridge sites to liquefaction in potential earthquakes. To perform this second fragility analysis, wall pier bridges within the southern Illinois random sample that may be susceptible to liquefaction were identified. A soil profile from each of these susceptible bridge sites was then subjected to randomly assigned bedrock motions, and an Arias intensity liquefaction analysis was carried out. From these analyses, a fragility curve for the potentially liquefiable wall pier supported bridge sites was produced. Overall results of this study indicate that southern Illinois wall pier supported bridges are moderately vulnerable to structural damage in a 2% probability of exceedance in 50 year earthquake, and in some cases they could also be highly vulnerable to on‐site liquefaction events. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of freezing, drying and the duration of storage on the composition of essential oils of plain‐leafed parsley [Petroselinum crispum (Mill.) Nym. ssp. neapolitanum Danert] and turnip‐rooted parsley [Petroselinum crispum (Mill.) Nym. ssp. tuberosum (Bernh.) Crov.]
Authors: Petropoulos Spiros A. , Daferera Dimitra , Polissiou Moschos G. , Passam Harold C.
Published: October 2009

The individual amounts of volatile substances occurring in turnip‐rooted parsley leaves [Petroselinum crispum (Mill.) Nym. ssp. tuberosum (Bernh.) Crov.] during freezing, drying and storage are described for the first time and compared with those of plain‐leafed parsley [Petroselinum crispum (Mill.) Nym. ssp. neapolitanum Danert]. Plain‐leafed parsley had a higher total oil content (mg/100 g fresh weight) than turnip‐rooted parsley, and was richer in β‐phellandrene, 1,3,8‐p‐menthatriene, apiole and myristicin, compounds that are considered to make a major contribution to parsley aroma. Freezing caused a slight reduction in the concentrations of β‐phellandrene and 1,3,8‐p‐menthatriene in plain‐leafed parsley, while drying caused a large decrease in 1,3,8‐p‐menthatriene and an increase in β‐phellandrene. In turnip‐rooted parsley the concentrations of 1,3,8‐p‐menthatriene, and to a lesser extent β‐phellandrene, also decreased with freezing, but 1,3,8‐p‐menthatriene increased with drying. Subsequent storage of the frozen or dried leaves caused a further loss of 1,3,8‐p‐menthatriene in all samples except the frozen leaves of turnip‐rooted parsley. In the frozen state, the loss of 1,3,8‐p‐menthatriene in plain‐leafed parsley coincided with an increase in apiole, myristicin, p‐α‐dimethylstyrene and terpinolene, whereas in turnip‐rooted parsley β‐myrcene and β‐phellandrene increased without a concomitant change in 1,3,8‐p‐menthatriene. In the dried state, 1,3,8‐p‐menthatriene decreased progressively over 2 months in turnip‐rooted parsley, while β‐phellandrene and, to a lesser extent, β‐myrcene, p‐α‐dimethylstyrene and terpinolene increased. In the dried leaves of plain‐leafed parsley, the loss of 1,3,8‐p‐menthatriene observed between the first and second months of storage coincided with increases in β‐phellandrene and β‐myrcene. It is concluded that the essential oil profile of parsley leaves depends on both the genotype and the processing method. Copyright © 2009 John Wiley & Sons, Ltd.
Regime‐switching in stock index and Treasury futures returns and measures of stock market stress
Authors: Bansal Naresh , Connolly Robert A. , Stivers Chris
Published: October 2009

We investigate bivariate regime‐switching in daily futures‐contract returns for the US stock index and ten‐year Treasury notes over the crisis‐rich 1997–2005 period. We allow the return means, volatilities, and correlation to all vary across regimes. We document a striking contrast between regimes, with a high‐stress regime that exhibits a much higher stock volatility, a much lower stock–bond correlation, and a higher mean bond return. The high‐stress regime is associated with higher average values of stock‐implied volatility, stock illiquidity, and stock and bond futures trading volume. The lagged implied volatility from equity‐index options is useful in modeling the time‐varying transition probabilities of the regime‐switching process. Our findings support the notions that: (1) stock market stress can have a material influence on Treasury bond pricing, and (2) the diversification benefits of combined stock–bond holdings tend to be greater during times with relatively high stock market stress. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 30:753–779, 2010
Do the dose or route of administration of norethisterone acetate as a part of hormone therapy play a role in risk of breast cancer: National‐wide case‐control study from Finland
Authors: Lyytinen Heli , Dyba Tadeusz , Pukkala Eero , Ylikorkala Olavi
Published: October 2009

We examined the associations between various doses and routes of administration of norethisterone acetate (NETA) in estrogen–progestagen therapy (EPT) and the risk of breast cancer in Finland. All Finnish women with first invasive breast cancer diagnosed between the ages of 50–62 during 1995–2007 (n = 9,956) were identified from the Finnish Cancer Registry. For each case, 3 controls of the same age were retrieved from the Finnish Population Register. The use of estradiol+NETA‐therapy by the cases and controls was traced from the national Medical Reimbursement Registry. The data were analyzed with multivariate conditional logistic regression, adjusting for parity, age at the first birth, and health care district. The continuous mode of NETA use tended to be associated with a higher rate ratio for breast cancer than the sequential use. The use of continuous “low” dose (NETA 0.5 mg + estradiol 1.0 mg) was associated with an increased rate ratio of breast cancer already in less than 3 years of use (odds ratio 1.94; 95% confidence interval 1.39–2.70) while a risk elevation for “high” dose (NETA 1.0 mg + estradiol 2.0 mg) was seen after 3 years use (1.71; 1.51–2.54). Oral and transdermal use of NETA were accompanied with comparable risks for breast cancer. In conclusion, the dose or route of administration of NETA in EPT do not modify the risks for breast cancer.
MicroRNA‐214 is aberrantly expressed in cervical cancers and inhibits the growth of HeLa cells
Authors: Yang Zuozhen , Chen Shuang , Luan Xuejing , Li Yixuan , Liu Min , Li Xin , Liu Tao , Tang Hua
Published: October 2009

MicroRNAs are a group of endogenously expressed, single‐stranded, 18–24 nt RNAs that regulate diverse cellular pathways. Although documented evidence indicates that some microRNAs can function as oncogenes or tumor‐suppressors, the role of miR‐214 in regulating human cervical cancer cells remains unexplored. We determined the expression level of miR‐214 and found it is downregulated in cervical cancer compared with normal tissue. Overexpression of miR‐214 in HeLa cells, a human cervical cancer cell line, significantly inhibited cell proliferation according to the MTT and colony forming assays. HeLa cells that stably overexpress miR‐214 downregulate the expression of MEK3 and JNK1 at both mRNA and protein levels. Further investigation revealed that miR‐214 regulates the expression of MEK3 and JNK1 by targeting the 3′UTRs of these genes. Collectively, these results suggest that miR‐214 negatively regulates HeLa cell proliferation by targeting the noncoding regions of MEK3 and JNK1 mRNAs. © 2009 IUBMB IUBMB Life, 61(11): 1075–1082, 2009
Limited information estimation and evaluation of DSGE models
Authors: Fukač Martin , Pagan Adrian
Published: October 2009

We advance the proposition that dynamic stochastic general equilibrium (DSGE) models should not only be estimated and evaluated with full information methods. These require that the complete system of equations be specified properly. Some limited information analysis, which focuses upon specific equations, is therefore likely to be a useful complement to full system analysis. Two major problems occur when implementing limited information methods. These are the presence of forward‐looking expectations in the system as well as unobservable non‐stationary variables. We present methods for dealing with both of these difficulties, and illustrate the interaction between full and limited information methods using a well‐known model. Copyright © 2009 John Wiley & Sons, Ltd.
Polysaccharide‐based vaccine delivery systems: Macromolecular assembly, interactions with antigen presenting cells, and in vivo immunomonitoring
Authors: Weber Caroline , Drogoz Alexandre , David Laurent , Domard Alain , Charles Marie‐Hélène , Verrier Bernard , Delair Thierry
Published: October 2009

Using a strategy of macromolecular assembly, a colloidal vaccine delivery system was obtained from chitosan and dextran sulfate and loaded with an antigenic protein (p24, the capsid protein of HIV‐1). The colloidal polyelectrolyte complexes (PECs) were obtained by charge neutralization of the polyanion and polycation at a charge ratio (n+/n−) of 2 (CHDS). The conditions of assembly were tuned to maintain the colloidal properties of the carrier in high salt environment. The relative molar masses of the two polyions and the degree of acetylation (DA) of chitosan were essential parameters to achieve this goal, and this could be related to the nanometric scale organization of the colloids observed by Small Angle X‐rays Scattering experiments. The binding of p24 to the colloidal carrier was achieved and the release of the antigen was investigated. Antigen presenting cells [dendritic cells (DCs)], obtained from monocytes, could internalize the colloids. Immature DCs (iDCs) were not matured by the colloidal PECs either loaded or not loaded with p24, as proved by Fluorescent Activated Cell Sorting (FACS) analysis. Despite this lack of in vitro interaction, a specific immune response was observed in mice with a high production of antibodies, after subcutaneous injection. The analysis of the interleukin production shows that both the cellular and the humoral responses were stimulated. This work brings a physico‐chemical insight on polysaccharide‐based antigen delivery systems and opens up new perspectives for their use as vaccine carriers. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Rooted induced trees in triangle‐free graphs
Authors: Pfender Florian
Published: October 2009

For a graph G, let t(G) denote the maximum number of vertices in an induced subgraph of Gthat is a tree. Further, for a vertex v∈V(G), let t(G, v) denote the maximum number of vertices in an induced subgraph of Gthat is a tree, with the extra condition that the tree must contain v. The minimum of t(G) (t(G, v), respectively) over all connected triangle‐free graphs G(and vertices v∈V(G)) on nvertices is denoted by t3(n) (t(n)). Clearly, t(G, v)⩽t(G) for all v∈V(G). In this note, we solve the extremal problem of maximizing |G| for given t(G, v), given that Gis connected and triangle‐free. We show that

and determine the unique extremal graphs. Thus, we get as corollary that \documentclass{article}\footskip=0pc\pagestyle{empty}\begin{document}$t_3(n)\ge t_3^{\ast}(n) = \lceil {\frac{1}{2}}(1+{\sqrt{8n-7}})\rceil$\end{document}, improving a recent result by Fox, Loh and Sudakov. © 2009 Wiley Periodicals, Inc. J Graph Theory 64: 206–209, 2010
On antimagic directed graphs
Authors: Hefetz Dan , Mütze Torsten , Schwartz Justus
Published: October 2009

An antimagic labeling of an undirected graph G with n vertices and m edges is a bijection from the set of edges of G to the integers {1, …, m} such that all n vertex sums are pairwise distinct, where a vertex sum is the sum of labels of all edges incident with that vertex. A graph is called antimagic if it admits an antimagic labeling. In (N. Hartsfield and G. Ringel, Pearls in Graph Theory, Academic Press, Boston, 1990, pp. 108–109), Hartsfield and Ringel conjectured that every simple connected graph, other than K2, is antimagic. Despite considerable effort in recent years, this conjecture is still open. In this article we study a natural variation; namely, we consider antimagic labelings of directed graphs. In particular, we prove that every directed graph whose underlying undirected graph is “dense” is antimagic, and that almost every undirected d‐regular graph admits an orientation which is antimagic. © 2009 Wiley Periodicals, Inc. J Graph Theory 64: 219–232, 2010
Ramsey‐type results for Gallai colorings
Authors: Gyárfás András , Sárközy Gábor N. , Sebő András , Selkow Stanley
Published: October 2009

A Gallai‐coloring of a complete graph is an edge coloring such that no triangle is colored with three distinct colors. Gallai‐colorings occur in various contexts such as the theory of partially ordered sets (in Gallai's original paper) or information theory. Gallai‐colorings extend 2‐colorings of the edges of complete graphs. They actually turn out to be close to 2‐colorings—without being trivial extensions. Here, we give a method to extend some results on 2‐colorings to Gallai‐colorings, among them known and new, easy and difficult results. The method works for Gallai‐extendible families that include, for example, double stars and graphs of diameter at most d for 2⩽d, or complete bipartite graphs. It follows that every Gallai‐colored Kn contains a monochromatic double star with at least 3n+ 1/4 vertices, a monochromatic complete bipartite graph on at least n/2 vertices, monochromatic subgraphs of diameter two with at least 3n/4 vertices, etc. The generalizations are not automatic though, for instance, a Gallai‐colored complete graph does not necessarily contain a monochromatic star on n/2 vertices. It turns out that the extension is possible for graph classes closed under a simple operation called equalization. We also investigate Ramsey numbers of graphs in Gallai‐colorings with a given number of colors. For any graph H let RG(r, H) be the minimum m such that in every Gallai‐coloring of Km with r colors, there is a monochromatic copy of H. We show that for fixed H, RG (r, H) is exponential in r if H is not bipartite; linear in r if H is bipartite but not a star; constant (does not depend on r) if H is a star (and we determine its value). © 2009 Wiley Periodicals, Inc. J Graph Theory 64: 233–243, 2010
Balanced coloring of bipartite graphs
Authors: Feige Uriel , Kogan Shimon
Published: October 2009

Given a bipartite graph G(U∪V, E) with n vertices on each side, an independent set I∈G such that |U∩I|=|V∩I| is called a balanced bipartite independent set. A balanced coloring of G is a coloring of the vertices of G such that each color class induces a balanced bipartite independent set in G. If graph G has a balanced coloring we call it colorable. The coloring number χB(G) is the minimum number of colors in a balanced coloring of a colorable graph G. We shall give bounds on χB(G) in terms of the average degree \documentclass{article}\usepackage{amssymb}\usepackage{amsbsy}\usepackage[mathscr]{euscript}\footskip=0pc\pagestyle{empty}\begin{document}$\bar{d}$\end{document} of G and in terms of the maximum degree Δ of G. In particular we prove the following:

\documentclass{article}\usepackage{amssymb}\usepackage{amsbsy}\usepackage[mathscr]{euscript}\footskip=0pc\pagestyle{empty}\begin{document}$\chi_{{{B}}}({{G}}) \leq {{max}} \{{{2}},\lfloor {{2}}\overline{{{d}}}\rfloor+{{1}}\}$\end{document}.

For any 0<ε<1 there is a constant Δ0 such that the following holds. Let G be a balanced bipartite graph with maximum degree Δ≥Δ0 and n≥(1+ε)2Δ vertices on each side, then \documentclass{article}\usepackage{amssymb}\usepackage{amsbsy}\usepackage[mathscr]{euscript}\footskip=0pc\pagestyle{empty}\begin{document}$\chi_{{{B}}}({{G}})\leq \frac{{{{20}}}}{\epsilon^{{{2}}}} \frac{\Delta}{{{{ln}}}\,\Delta}$.\end{document}

© 2009 Wiley Periodicals, Inc. J Graph Theory 64: 277–291, 2010
Synaptic localization of neuroligin 2 in the rodent retina: Comparative study with the dystroglycan‐containing complex
Authors: Lui Leona , Levinson Joshua N. , Noël Geoffroy , Handrigan Gregory R. , Richman Joy M. , El‐Husseini Alaa , Moukhles Hakima
Published: October 2009

Several recent studies have shown that neuroligin 2 (NL2), a component of the cell adhesion neurexins–neuroligins complex, is localized postsynaptically at hippocampal and other inhibitory synapses throughout the brain. Other studies have shown that components of the dystroglycan complex are also localized at a subset of inhibitory synapses and are coexpressed with NL2 in brain. These data prompted us to undertake a comparative study between the localization of NL2 and the dystroglycan complex in the rodent retina. First, we determined that NL2 mRNA is expressed both in the inner and in the outer nuclear layers. Second, we found that NL2 is localized both in the inner and in the outer synaptic plexiform layers. In the latter, the horseshoe‐shaped pattern of NL2 and its extensive colocalization with RIM2, a component of the presynaptic active zone at ribbon synapses, argue that NL2 is localized presynaptically at photoreceptor terminals. Third, comparison of NL2 and the dystroglycan complex distribution patterns reveals that, despite their coexpression in the outer plexiform layer, they are spatially segregated within distinct domains of the photoreceptor terminals, where NL2 is selectively associated with the active zone and the dystroglycan complex is distally distributed in the lateral regions. Finally, we report that the dystroglycan deficiency in the mdx3cv mouse does not alter NL2 localization in the outer plexiform layer. These data show that the NL2‐ and dystroglycan‐containing complexes are differentially localized in the presynaptic photoreceptor terminals and suggest that they may serve distinct functions in retina. © 2009 Wiley‐Liss, Inc.
DHA diet reduces AD pathology in young APPswe/PS1ΔE9 transgenic mice: Possible gender effects
Authors: Perez Sylvia E. , Berg Brian M. , Moore Kenneth A. , He Bin , Counts Scott E. , Fritz Jason J. , Hu Yuan‐Shih , Lazarov Orly , Lah James J. , Mufson Elliott J.
Published: October 2009

Epidemiological and clinical trial findings suggest that consumption of docosahexaenoic acid (DHA) lowers the risk of Alzhemier's disease (AD). We examined the effects of short‐term (3 months) DHA enriched diet on plaque deposition and synaptic deficts in forebrain of young APPswe/PS1ΔE9 transgenic (tg) and non‐transgenic (ntg) mice. Gas chromatography revealed a significant increase in DHA concomitant with a decrease of arachidonic acid in both brain and liver in mice fed with DHA. Female tg mice consumed relatively more food daily than ntg female mice, independent of diet. Plaque load was significantly reduced in the cortex, ventral hippocampus and striatum of female APPswe/PS1ΔE9 tg mice on DHA diet compared to female tg mice on control diet. Immunoblot quantitation of the APOE receptor, LR11, which is involved in APP trafficking and Aβ production, were unchanged in mice on DHA or control diets. Moreover drebrin levels were significantly increased in the hippocampus of tg mice on the DHA diet. Finally, in vitro DHA treatment prevented amyloid toxicity in cell cultures. Our findings support the concept that increased DHA consumption may play and important role in reducing brain insults in female AD patients. © 2009 Wiley‐Liss, Inc.
Qualitätskontrolle bei Laserschweißnähten
Authors: Döttinger Christoph
Published: October 2009

Im Eiltempo hat das Laserschweißen als Innovatives Fügeverfahren einen festen Platz in der Automobilindustrie erobert. Adäquate Methoden zur Qualitätskontrolle und Fehlerdiagnose konnten hier nur schwer Schritt halten. Abhilfe schaffen kann hier eine neue Generation automatischer Prüfanlagen für Laserschweißnähte, die von der Thermosensorik GmbH aus Erlangen entwickelt wurde: Buchstäblich blitzschnell, d.h. in wenigen 100 Millisekunden, durchläuft die von einem Blitz angeregte Wärmewelle das Karosseriebauteil. Gleichzeitig wird ein Infrarotvideo der gegenüberliegenden Bauteiloberfläche aufgenommen. Dieses gibt Aufschluss über die Qualität der Schweißnaht. Doch wie funktioniert dieses Verfahren?
Hoch intensiv und scharf gebündelt
Authors: Hopp Georg
Published: October 2009

In der Lasermaterialbearbeitung sind technische Gase unverzichtbar. Durch die Auswahl des passenden Schutzgases oder die Entwicklung eines maßgeschneiderten Gasgemischs sowie eines hochwertigen Versorgungssystems lassen sich wirtschaftliche und qualitative Faktoren des Schweiß‐ und Schneidprozesses maßgeblich beeinflussen. Damit können höhere Produktionsraten und bessere Bearbeitungsqualitäten bei gleichzeitig sinkenden Kosten erzielt werden. So führen beispielsweise in der Blechbearbeitung Helium‐Gemische mit Argon oder Wasserstoff oft zu besseren Resultaten als reines Helium. Von den Vorteilen dieser Gase und Gasgemische profitieren nicht nur Großunternehmen, sondern auch kleine und mittelständische Betriebe. Die Bedeutung der Gase für den Laserschweißprozess wird mit der Verbreitung des Laserhybrid‐Verfahrens noch weiter steigen.
SCHWEISSEN & SCHNEIDEN 2009
Authors: Middeldorf Klaus
Published: October 2009

Die großen Messen sind derzeit gute Plätze um ein aktuelles Bild von der Wirtschaftslage zu bekommen. Auf der SCHWEISSEN & SCHNEIDEN war die Stimmung gut, ein vorsichtiger Optimismus war zu spüren. Mit dem Hauptgeschäftsführer des DVS – Deutscher Verband für Schweißen und Verwandte Verfahren e. V. sprach Andreas Thoß über die Rolle der Laserverfahren in der Fügetechnik und über die aktuelle Marktentwicklung.
High‐frequency mode conversion technique for stiff lesion detection with magnetic resonance elastography (MRE)
Authors: Mariappan Yogesh K. , Glaser Kevin J. , Manduca Armando , Romano Anthony J. , Venkatesh Sudhakar K. , Yin Meng , Ehman Richard L.
Published: October 2009

A novel imaging technique is described in which the mode conversion of longitudinal waves is used for the qualitative detection of stiff lesions within soft tissue using magnetic resonance elastography (MRE) methods. Due to the viscoelastic nature of tissue, high‐frequency shear waves attenuate rapidly in soft tissues but much less in stiff tissues. By introducing minimally‐attenuating longitudinal waves at a significantly high frequency into tissue, shear waves produced at interfaces by mode conversion will be detectable in stiff regions, but will be significantly attenuated and thus not detectable in the surrounding soft tissue. This contrast can be used to detect the presence of stiff tissue. The proposed technique is shown to readily depict hard regions (mimicking tumors) present in tissue‐simulating phantoms and ex vivo breast tissue. In vivo feasibility is demonstrated on a patient with liver metastases in whom the tumors are readily distinguished. Preliminary evidence also suggests that quantitative stiffness measurements of stiff regions obtained with this technique are more accurate than those from conventional MRE because of the short shear wavelengths. This rapid, qualitative technique may lend itself to applications in which the localization of stiff, suspicious neoplasms is coupled with more sensitive techniques for thorough characterization. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Viable tumor tissue detection in murine metastatic breast cancer by whole‐body MRI and multispectral analysis
Authors: Barck Kai H. , Willis Brandon , Ross Jed , French Dorothy M. , Filvaroff Ellen H. , Carano Richard A. D.
Published: October 2009

Whole‐body MRI combined with a semiautomated hierarchical multispectral image analysis technique was evaluated as a method for detecting viable tumor tissue in a murine model of metastatic breast cancer (4T1 cell line). Whole‐body apparent diffusion coefficient, T2, and proton density maps were acquired in this study. The viable tumor tissue segmentation included three‐stage k‐means clustering of the parametric maps, morphologic operations, application of a size threshold, and reader discrimination of the segmented objects. The segmentation results were validated by histologic evaluation, and the detection accuracy of the technique was evaluated at three size thresholds (15, 100, and 500 voxels). The accuracy was 88.9% for a 500‐voxel size threshold, and the area under receiver operating characteristic curve was 0.84. The regions of segmented viable tumor tissue within the primary tumors were found mostly on the periphery of the tumors in agreement with the histologic findings. The presented technique was found capable of detecting metastases and segmenting the viable tumor from necrotic regions within tumors found in this model. It offers a noninvasive, whole‐body, viable tumor tissue detection method for preclinical and potentially clinical applications such as tumor screening and evaluating therapeutic efficacy. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Superparamagnetic iron oxide nanoparticles as a dual imaging probe for targeting hepatocytes in vivo
Authors: Lee Chang‐Moon , Jeong Hwan‐Jeong , Kim Eun‐Mi , Kim Dong Wook , Lim Seok Tae , Kim Hyoung Tae , Park In‐Kyu , Jeong Yong Yeon , Kim Jin Woong , Sohn Myung‐Hee
Published: October 2009

Hepatocyte‐specific targeting agents are useful for evaluation of the hepatocytic function and the monitoring of disease progress. Superparamagnetic iron oxide nanoparticles (SPION) bearing terminal galactose groups exhibit a high affinity for the asialoglycoprotein receptor on the hepatocyte surface. In this study, we synthesized and characterized the dual probe SPION detectable by both nuclear and MR imaging modality for specifically targeting hepatocytes in vivo. SPION with 12‐nm diameter were functionalized with dopamine. Surface modification of the SPION was performed to target asialoglycoprotein receptor on hepatocytes, using lactobionic acid. Transmission electron microscope images demonstrated that SPION displayed highly uniform characteristics in terms of both particle size and shape. The X‐ray diffraction pattern of SPION revealed a nanocrystal structure of magnetite. To radiolabel the magnetite with 99mTc, diethylenetriaminepentaacetic acid was conjugated to unreacted functional groups of dopamine. 99mTc‐labeled lactobionic acid‐SPION showed high accumulation in liver, with 38.43 ± 6.45% injected dose per gram. In MR imaging, the reduction of the T2 signal in the liver by lactobionic acid‐SPION was approximately 50.8 ± 7.3%. Competition studies and transmission electron microscope images of liver tissues demonstrated that the lactobionic acid‐SPION were localized in hepatocytes. Therefore, the lactobionic acid‐SPION may be used as a hepatocyte‐targeted dual contrast agent for both nuclear and MR imaging. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Characterizing healthy and diseased white matter using quantitative magnetization transfer and multicomponent T2 relaxometry: A unified view via a four‐pool model
Authors: Levesque Ives R. , Pike G. Bruce
Published: October 2009

Nuclear magnetic resonance relaxation and magnetization transfer in cerebral white matter can be described using a four‐pool model: two for water protons (in separate myelin and intra/extracellular compartments) and two for protons associated with the lipids and proteins of biologic membranes (of myelin and nonmyelin semisolids). This model was used to gain insight into the observations from multicomponent quantitative T2 relaxometry and quantitative magnetization transfer imaging, both based on simplified white matter models and experimentally feasible in vivo. Using a set of coupled Bloch equations describing the behavior of the magnetization in a four‐pool model of white matter, simulations of the quantitative T2 relaxometry and quantitative magnetization transfer imaging techniques were performed. Pathology‐inspired modifications were made to the four‐pool model to gauge their impact on quantitative T2 relaxometry and quantitative magnetization transfer imaging observations. Our results show that changes in the rate of water movement between microanatomic compartments may impact otherwise stable quantitative T2 relaxometry observations; that the measure of the quantitative magnetization transfer imaging–based semisolid pool population is robust, despite the presence of two distinct semisolid components; and that quantitative magnetization transfer imaging compartment size estimates are not influenced by changes in the T2 of the intra/extracellular water pool. The four‐pool model, while impractical for in vivo characterization, yields important insight into the interpretation of changes observed with these quantitative MRI methods based on simplified models of white matter. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Investigation and modeling of magnetization transfer effects in two‐dimensional multislice turbo spin echo sequences with low constant or variable flip angles at 3 T
Authors: Weigel Matthias , Helms Gunther , Hennig Juergen
Published: October 2009

Magnetization transfer effects represent a major source of contrast in multislice turbo spin echo sequences (TSE)/fast spin echo sequences. Generally, low refocusing flip angles have become common in such MRI sequences, especially to mitigate specific absorption rate problems. Since the strength of magnetization transfer effects is related to the radiofrequency power and therefore specific absorption rate applied, magnetization transfer induced signal attenuations are investigated for a variety of TSE sequences with low constant and variable flip angles. Noticeable differences between the sequences have been observed. In particular, fewer signal attenuations are observed for TSE with low flip angles such as hyperecho‐TSE and smooth transitions between pseudo steady states–TSE, leading to contrast that is less dependent on the number of slices. It is shown that the strength of the magnetization transfer‐induced signal attenuations can be understood and described by a physical framework, which is based on the mean square flip angle of a given TSE sequence. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Characterization of T2* heterogeneity in human brain white matter
Authors: Li Tie‐Qiang , Yao Bing , van Gelderen Peter , Merkle Hellmut , Dodd Stephen , Talagala Lalith , Koretsky Alan P. , Duyn Jeff
Published: October 2009

Recent in vivo MRI studies at 7.0 T have demonstrated extensive heterogeneity of T2* relaxation in white matter of the human brain. In order to study the origin of this heterogeneity, we performed T2* measurements at 1.5, 3.0, and 7.0 T in normal volunteers. Formalin‐fixed brain tissue specimens were also studied using T2*‐weighted MRI, histologic staining, chemical analysis, and electron microscopy. We found that T2* relaxation rate (R2* = 1/T2*) in white matter in living human brain is linearly dependent on the main magnetic field strength, and the T2* heterogeneity in white matter observed at 7.0 T can also be detected, albeit more weakly, at 1.5 and 3.0 T. The T2* heterogeneity exists also in white matter of the formalin‐fixed brain tissue specimens, with prominent differences between the major fiber bundles such as the cingulum (CG) and the superior corona radiata. The white matter specimen with substantial difference in T2* has no significant difference in the total iron content, as determined by chemical analysis. On the other hand, evidence from histologic staining and electron microscopy demonstrates these tissue specimens have apparent difference in myelin content and microstructure. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Delayed gadolinium‐enhanced magnetic resonance imaging (dGEMRIC) of hip joint cartilage in femoroacetabular impingement (FAI): Are pre‐ and postcontrast imaging both necessary?
Authors: Bittersohl Bernd , Hosalkar Harish S. , Kim Young‐Jo , Werlen Stefan , Siebenrock Klaus A. , Mamisch Tallal C.
Published: October 2009

The purpose of this study was to assess if delayed gadolinium MRI of cartilage using postcontrast T1 (T1Gd) is sufficient for evaluating cartilage damage in femoroacetabular impingement without using noncontrast values (T10). T1Gd and ΔR1 (1/T1Gd − 1/T10) that include noncontrast T1 measurements were studied in two grades of osteoarthritis and in a control group of asymptomatic young‐adult volunteers. Differences between T1Gd and ΔR1 values for femoroacetabular impingement patients and volunteers were compared. There was a very high correlation between T1Gd and ΔR1 in all study groups. In the study cohort with Tonnis grade 0, correlation (r) was −0.95 and −0.89 with Tonnis grade 1 and −0.88 in asymptomatic volunteers, being statistically significant (P < 0.001) for all groups. For both T1Gd and ΔR1, a statistically significant difference was noted between patients and control group. Significant difference was also noted for both T1Gd and ΔR1 between the patients with Tonnis grade 0 osteoarthritis and those with grade 1 changes. Our results prove a linear correlation between T1Gd and ΔR1, suggesting that T1Gd assessment is sufficient for the clinical utility of delayed gadolinium MRI of cartilage in this setting and additional time‐consuming T10 evaluation may not be needed. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Reconstruction from free‐breathing cardiac MRI data using reproducing kernel Hilbert spaces
Authors: Cîndea Nicolae , Odille Freddy , Bosser Gilles , Felblinger Jacques , Vuissoz Pierre‐André
Published: October 2009

This paper describes a rigorous framework for reconstructing MR images of the heart, acquired continuously over the cardiac and respiratory cycle. The framework generalizes existing techniques, commonly referred to as retrospective gating, and is based on the properties of reproducing kernel Hilbert spaces. The reconstruction problem is formulated as a moment problem in a multidimensional reproducing kernel Hilbert spaces (a two‐dimensional space for cardiac and respiratory resolved imaging). Several reproducing kernel Hilbert spaces were tested and compared, including those corresponding to commonly used interpolation techniques (sinc‐based and splines kernels) and a more specific kernel allowed by the framework (based on a first‐order Sobolev RKHS). The Sobolev reproducing kernel Hilbert spaces was shown to allow improved reconstructions in both simulated and real data from healthy volunteers, acquired in free breathing. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.
2D modelling of a dry joint masonry wall retaining a pulverulent backfill
Authors: Colas A. S. , Morel J. C. , Garnier D.
Published: October 2009

This work focuses on an analysis of dry joint retaining structures based on yield design theory: the stability of the masonry is assessed using rigid block and shear failure mechanisms in the wall and its backfill. An application of this simulation on 2D scale‐down brick and wood models is then addressed, showing close agreement between theoretical predictions and experimental results. Further development on this work, including application of this theory on dry‐stone retaining walls, is discussed as a conclusion. Copyright © 2009 John Wiley & Sons, Ltd.
A coupled model for prediction of settlement and gas flow in MSW landfills
Authors: Yu L. , Batlle F. , Lloret A.
Published: October 2009

Prediction of long‐term settlement and control of gas pollution to the environment are two principle concerns during the management of municipal solid waste (MSW) landfills. The behavior of settlement and gas flow in MSW landfills is complicated due to the combined effect of mechanical deformation of the solid skeleton and continuous biodegradation of the waste. A one‐dimensional settlement and gas flow model is presented in this paper, which is capable of predicting time evolution of settlement as well as temporal and spatial distribution of gas pressure within multi‐layered landfills under a variety of operating scenarios. The analytical solution to the novel model is evaluated with numerical simulation and field measurements. The resulting efficiency and accuracy highlight the capability of the proposed model to reproduce the settlement behavior and gas flow in MSW landfills. The influences of operating conditions and waste properties on settlement and gas pressure are examined for typical MSW landfills. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of pile installation on adjacent structures
Authors: Henke S.
Published: October 2009

Pile installation leads to significant changes in the main state variables of the surrounding soil. In addition, the installation process may have an influence on adjacent or intersecting structures such as pile grillages. In this paper, three‐dimensional numerical analyses are presented to investigate the effects of pile driving with open or closed cross‐sections on the surrounding soil and on adjacent structures. Two different installation methods are used: quasi‐static pile jacking and vibratory pile driving. The numerical models are evaluated and verified using data from field tests performed in situ during the construction of the quay wall at the container terminal CT4 in Bremerhaven.

Two case studies are presented to characterize the main influence factors for additional loading on adjacent structures due to pile installation.

Finally, a parametric study is conducted showing the influence of the installation method, pile cross‐section and distance of a pile from an existing structure on the additional loading for this structure. Copyright © 2009 John Wiley & Sons, Ltd.
Synchronously synthesizing and immobilizing porphyrins on crosslinked polystyrene microspheres and preliminary study on catalytic activity of supported metalloporphyrins
Authors: Gao Baojiao , Zhang Guohai , Li Yanbin , Du Ruikui
Published: October 2009

A novel method for immobilizing porphyrins as well as metalloporphyrins (MPs) on polymeric supports was found, and it is the way to synchronously synthesize and immobilize porphyrins on polymeric microspheres. By using 4‐hydroxybenzaldehyde (HBA)‐bound crosslinked polystyrene (CPS) microspheres, pyrrole, and benzaldehyde in a solution as co‐reactants and through the Adler's reaction between solid–liquid phases, it was successfully realized to simultaneously synthesize and immobilize phenyl porphyrin (PP) on CPS microspheres, resulting in PP‐supported microspheres PP–CPS. With the same method, substituted PPs, 4‐chlorophenyl porphyrin (CPP) and 4‐nitrophenyl porphyrin (NPP), were also successfully immobilized on CPS microspheres by using substituted benzaldehydes, 4‐chlorobenzaldehyde and 4‐nitrobenzaldehyde, as one reactant in the solution, respectively, and other two porphyrin‐supported microspheres, CPP–CPS and NPP–CPS, were obtained. The effects of various factors on the process of synchronously synthesizing and immobilizing porphyrins on CPS microspheres were mainly studied. Further, the coordination reaction of cobalt salt with PP–CPS as well as CPP–CPS and NPP–CPS was conducted, forming three solid catalysts, CoPP–CPS, CoCPP–CPS, and CoNPP–CPS. The catalytic properties of these catalysts in the catalytic oxidation of ethylbenzene to acetophenone by dioxygen were preliminarily examined. The experimental results indicate that the Adler's reaction between solid–liquid phases, namely the reaction between HBA‐bound CPS microspheres and pyrrole as well as free benzaldehyde or analogs in the solution can favorably be carried out. For this process, the fitting protonic acid catalyst is p‐nitrobenzoic acid and appropriate solvent is dimethyl sulfoxide (DMSO). By comparison, the process of preparing CPP–CPS microspheres is easier to be carried out. The obtained three solid catalysts can effectively catalyze the oxidation of ethylbenzene to acetophenone by dioxygen. In comparison, the catalytic activity of CoNPP–CPS is the highest. Copyright © 2009 John Wiley & Sons, Ltd.
An investigation on the mechanical and dynamic rheological properties of single and hybrid filler/polypropylene composites based on talc and calcium carbonate
Authors: Azizi Hamed , Faghihi Jalal
Published: October 2009

Some results of experiments on the mechanical and rheological properties of mineral filled polypropylene were presented. Single filler and hybrid filler composites of talc and calcium carbonate (CaCO3) were prepared in a co‐rotating twin‐screw extruder. The effect of filler type, filler content, and coupling agent on the mechanical and rheological properties of the polypropylene were studied. The coupling agent was maleic anhydride‐grafted polypropylene (PP‐g‐MA). It was found that the mechanical properties are affected by filler type, filler concentration, and the interaction between filler and matrix. The tensile strength of the composite is more affected by the talc while the impact strength is influenced mostly by CaCO3 content. The elongation at break of PP/CaCO3 composites was higher than that of PP/talc composites. The incorporation of coupling agent into PP/mineral filler composites increased the mechanical properties. Rheological properties indicated that the complex viscosity and storage modulus of talc filled samples were higher than those of calcium carbonate filled samples while the tan δ was lower. The rheological properties of hybrid‐filler filled sample were more affected by the talc than calcium carbonate. The PP‐g‐MA increased the complex viscosity and storage modulus of both single and hybrid composites. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Pravastatin use and cancer risk: a meta‐analysis of individual patient data from long‐term prospective controlled trials in Japan
Authors: Matsushita Yasuyuki , Sugihara Masahiro , Kaburagi Junpei , Ozawa Masumi , Iwashita Mikio , Yoshida Sanae , Saito Hanako , Hattori Yoko
Published: October 2009

Purpose

To assess the influence of pravastatin therapy on cancer morbidity and mortality by a meta‐analysis of individual patient data (IPD) from three independent Japanese large‐scale clinical trials.

Methods

We conducted a meta‐analysis of IPD collected from three large‐scale prospective studies, the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study, Kyushu Lipid Intervention Study (KLIS), and Hokuriku Lipid Coronary Heart Disease Study‐Pravastatin Atherosclerosis Trial (Holicos‐PAT), which compared cardiovascular outcomes with pravastatin therapy and non‐statin therapy in Japanese patients with hypercholesterolemia over a follow‐up period of ≥4 years. The incidence of cancer or cancer death in the pravastatin and non‐statin therapy groups was compared by multivariate Cox proportional hazard models stratified by trial. Subgroup analyses by sex and age were also conducted using the same methods.

Results

In a total of 13 724 patients (mean age, 58 years; women, 48%) included in the analyses, pravastatin was not associated with an increased risk of developing cancer (hazard ratio [HR], 0.99; 95% confidence interval [95%CI], 0.81–1.19). Similarly, pravastatin therapy did not statistically affect cancer death (HR, 0.86; 95%CI, 0.61–1.21). Moreover, in subgroups analyses, no influence was observed on cancer incidence or death in relation to sex and age.

Conclusion

Pravastatin did not increase the rate of cancer incidence or cancer death in a large population of Japanese patients followed for >70 000 patient‐years. Copyright © 2009 John Wiley & Sons, Ltd.