bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil‐structure interaction for tower structures
Authors: Warburton G. B.
Published: March 2007

The soil‐structure system is modelled as a uniform vertical beam, which terminates in a base or foundation mass; this mass is attached to the surface of an elastic half‐space. Using known force‐displacement relations for the coupled vibrations of a rigid disc on an elastic half‐space, the natural frequencies and response to a transverse harmonic force, applied at the tip of the beam, are determined through a continuum approach. Effectively the problem reduces to a beam with frequency‐dependent boundary conditions. A parametric study shows that changes in the three ratios, Young's modulus for the beam to that for the half‐space, the radius of the base mass to the length of the beam, L, and the second moment of area of the beam cross‐section/L4, cause large variations in the maximum response, which due to interaction can be considerably smaller or larger than that for a comparable fixed‐base cantilever beam. This dynamic behaviour can be explained by considering the variation of natural frequencies, mode shapes and modal damping factors with these ratios.

A brief study of the response of the structure to a free‐field harmonic acceleration, applied at the soil‐structure interface, suggests that interaction depends upon material and geometric properties of the system, rather than on the nature of the excitation.
Dynamic interaction for idealized off‐shore structures
Authors: Warburton G. B. , Hutton S. G.
Published: March 2007

The structure is idealized as a uniform slender beam of circular cross‐section which supports a rigid tip mass and which is connected at its base to a rigid foundation mass, the latter being attached to the surface of a visco‐elastic half‐space. An analytical solution for harmonic response of the partially submerged structure is obtained in terms of the normal modes of the corresponding structure in vacuo. This is achieved by introducing fluid‐structure coupling into the model. A similar structural model has been described in a companion paper and used to study soil‐structure interaction. Numerical results show the dependence of response on various parameters and contribute towards a better understanding of the dynamics of off‐shore towers.
Non‐linear analysis of coupled wall systems
Authors: Takayanagi Takehira , Schnobrich William C.
Published: March 2007

The non‐linear response history and failure mechanism of coupled wall systems under dynamic loads and static loads are investigated through an analytical model. The walls and coupling beams are replaced by flexural elements. Axial and shear stiffnesses are included for the wall members. The stiffness characteristics of each member are determined by inelastic properties. The suitable hysteresis loops to each constituent member are established to include the specific characteristics of coupled wall systems. The computed results are compared with results obtained from tests using model structures statically and dynamically tested on the Illinois Earthquake Simulator.
Evaluating the seismic reliability of electrical equipment containing ceramic structural members
Authors: Schiff Anshel J. , Torres‐Cabrejos Rafael E. , Yao James T. P.
Published: March 2007

A method for evaluating the reliability of ceramic structural members subjected to earthquake‐induced vibrations is presented. The method uses the Weibull distribution to represent the probability of failure of the brittle ceramic material and includes the effects of stress concentrations introduced by flaws and the volume of material subjected to stress. The stress concentration introduced by the complex form of insulators and at the mounting interfaces is considered. A numerical example is given to illustrate the application of the method.
Seismic response of long curved bridge structures: Experimental model studies
Authors: Williams David , Godden William
Published: March 2007

This paper presents the results of a shaking table study conducted on the seismic behaviour of curved reinforced concrete bridge structures of the type used in highway interchanges. A series of representational 1/30th scale models was constructed in microconcrete to study the effects of both linear and non‐linear dynamic behaviour, the non‐linearity including sliding and impacting at the expansion joints and ductility in the columns. Each model was subjected to a series of increasingly severe simulated earthquakes in the longitudinal and transverse directions, both with and without the vertical component. Response data were recorded in the form of selected displacement time‐histories which were subsequently used as control data in a companion theoretical study. Each model was eventually taken to failure which consisted primarily of extensive damage at the expansion joints. The paper concludes with general observations on the seismic behaviour of long‐span long‐period curved bridges, and emphasizes the sensitivity of this behaviour to the location and design of the joints.
Numerical modelling of the industrial silicon single crystal growth processes
Authors: Nacke Bernard , Muiznieks Andris
Published: March 2007

Silicon wafers produced from the silicon single crystals are the basic material for the manufacturing of various kinds of electronic devices determining the everyday life of the modern society. Silicon single crystals industrially are mainly grown by two methods ‐ by the Czochralski and by the floating zone technique. Both of them involve various physical processes with complex interactions which makes the experimental optimization of the growth techniques a rather hard and expensive task. Therefore, mathematical modelling supported by the rapid increase of the computer power has become an effective means in the development of the industrial crystal growth. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transition to Turbulence in the Hartmann Boundary Layer
Authors: Thess André , Krasnov Dmitry , Boeck Thomas , Zienicke Egbert , Zikanov Oleg , Moresco Pablo , Alboussière Thierry
Published: March 2007

The Hartmann boundary layer is a paradigm of magnetohydrodynamic (MHD) flows. Hartmann boundary layers develop when a liquid metal flows under the influence of a steady magnetic field. The present paper is an overview of recent successful attempts to understand the mechanisms by which the Hartmann layer undergoes a transition from laminar to turbulent flow. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of turbulent metal flows
Authors: Baake E. , Umbrashko A. , Nacke B. , Jakovics A.
Published: March 2007

Comprehensive knowledge of the heat and mass transfer processes in turbulent metal flows is required to realize efficient and reliable melting and casting processes. Experimental and numerical studies of the melt flow in induction furnaces show that the flow pattern, which comprise several vortexes of the mean flow, and the temperature distribution in the melt are significantly influenced by low‐frequency large scale flow oscillations. Two‐ and three‐dimensional hydrodynamic calculations of the melt flow, using two‐equation turbulence models based on Reynolds Averaged Navier‐Stokes approach, do not predict the large scale periodic flow instabilities obtained from the experimental data. That's why the Large Eddy Simulation (LES) numerical technique was approved to be an alternative for the various k ‐ε model modifications. In order to investigate convective scalar transport mechanism in the considered flow the discrete particle tracing approach has been carried out. The studies, presented in this paper, content the numerical simulation of turbulent melt flow of experimental and industrial size induction furnaces and demonstrate the possibility of using the three‐dimensional transient LES approach for successful simulation of heat and mass transfer processes in metallurgical applications. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Control of weakly conductive fluids by near wall Lorentz forces
Authors: Hinze M.
Published: March 2007

In this work optimal and model‐predictive control approaches for control of weakly conductive fluids are developed. The flow around the circular cylinder at low Reynolds numbers serves as prototyping application. Control by near‐wall Lorentz forces gains either to suppress the formation of the von Kármán Vortex Street, or to reduce the drag. Besides a concise mathematical modelling numerical examples are presented which highlight the scope of the presented control approaches. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Forward and inverse problems in MHD: Numerical and experimental results
Authors: Stefani Frank , Gailitis Agris , Gerbeth Gunter , Gundrum Thomas , Xu Mingtian
Published: March 2007

When a conducting fluid comes under the influence of a magnetic field, electrical currents are induced that give rise to a modification of this magnetic field. The ratio of induced magnetic field to applied magnetic field is characterized by the magnetic Reynolds number Rm of the flow. For large Rm, even self‐excitation of a magnetic field can occur. Thishydromagnetic dynamo effectis responsible for the maintenance of the magnetic fields of planets, stars and galaxies. In the present paper, we delineate some recent developments in the numerical treatment of induction effects in arbitrary geometry, and their application for dynamo experiments as well as for a “Contactless Inductive Flow Tomography (CIFT)”. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Boundary Perturbation Methods for Water Waves
Authors: Nicholls David P.
Published: March 2007

The most successful equations for the modeling of ocean wave phenomena are the free–surface Euler equations. Their solutions accurately approximate a wide range of physical problems from open–ocean transport of pollutants, to the forces exerted upon oil platforms by rogue waves, to shoaling and breaking of waves in nearshore regions. These equations provide numerous challenges for theoreticians and practitioners alike as they couple the difficulties of a free boundary problem with the subtle balancing of nonlinearity and dispersion in the absence of dissipation. In this paper we give an overview of, what we term, “Boundary Perturbation” methods for the analysis and numerical simulation of this “water wave problem”. Due to our own research interests this review is focused upon the numerical simulation of traveling water waves, however, the extensive literature on the initial value problem and additional theoretical developments are also briefly discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mainstreaming rural poor in water resources management: preliminary lessons of a bottom‐up WUA development approach in Central Asia
Authors: Yakubov Murat , Hassan Mehmood Ul
Published: March 2007

This paper draws upon experiences in Central Asia with irrigation management transfer arising from a development project currently underway in the Fergana Valley of Central Asia. One of the main features of the project is that it gives much attention to social mobilization in order to bring required water management change and get those at the grassroots duly organized, educated and empowered to truly self‐own and manage their community‐based organization. The paper, through analysis of users' perception before and after the mobilization, documents the changes in, attitudes and knowledge of, and the performance of water users' associations through, users' perspectives. Though no major breakthroughs have been found so far in the quality of irrigation and drainage services provided, there are clear indications that increased grassroots knowledge and awareness about water and irrigation management through intensive mobilization, regular involvement and exposure of the entire water user community to WUA management, planning and operation matters and decision‐making do have a positive bearing on their attitudes, behaviours, capacities and skills, adding considerably to their overall social capital and thus enhancing their chance for a better livelihood. Copyright © 2007 John Wiley & Sons, Ltd.
Understanding gender and diversity dimensions of irrigation management for pro‐poor interventions
Authors: Hussain Intizar
Published: March 2007

This paper offers a critical review and synthesis of key issues and lessons on gender and diversity dimensions of irrigation in the context of poverty alleviation interventions. The paper is a part of the multi‐country study carried out by the author at the International Water Management Institute (IWMI) in collaboration with national partners in six Asian countries (Bangladesh, China, India, Indonesia, Pakistan and Vietnam) during 2001–2002. The paper suggests that, while making large contributions to irrigated agriculture, women depend on, and benefit from, irrigation water in a variety of ways including water uses for domestic and livelihood purposes. Gender and diversity aspects are critical in irrigation management that aims to address poverty issues. An understanding of these aspects is important for designing pro‐poor interventions in irrigated agriculture. Women and low socio‐economic groups have benefited where gender and diversity issues have been incorporated in policy formulation, project design and implementation. Designing the irrigation infrastructure such that the irrigation systems become multiple use systems can enhance the benefits of investments in irrigation for the poor women. Finally, the paper suggests that policy and project level interventions that aim to address gender and diversity issues need to focus not only on areas predominantly inhabited by the poor belonging to low castes, clans, tribes and ethnic minorities, but also in areas where such groups are in minorities. Copyright © 2007 John Wiley & Sons, Ltd.
Poverty‐reducing impacts of irrigation: evidence and lessons
Authors: Hussain Intizar
Published: March 2007

This paper is part of the multi‐country study on “pro‐poor intervention strategies in irrigated agriculture in Asia” carried out by the author at the International Water Management Institute (IWMI) in collaboration with national partners in six Asian countries, namely Bangladesh, China, India, Indonesia, Pakistan and Vietnam. The study is largely based on primary data collected from over 5400 households in 26 irrigation systems during 2001–2002. This paper summarizes the findings of the study, and further extends the results (as presented in the sister paper in this Special Issue) on direct and indirect benefits and disbenefits of irrigation in terms of their poverty alleviation impacts. The paper examines evidence on poverty‐reducing impacts of irrigation in local settings as well as at broader regional levels, and also looks into key factors influencing these impacts, and attempts to answer the following key questions: (i) what is the magnitude of impact of irrigation on poverty reduction; (ii) what is the response of poverty reduction to irrigation or irrigation‐induced expansion in agricultural output across various settings; (iii) do poverty‐reducing impacts of irrigation vary across systems, and if so, why? Or what are the conditioning factors that determine the anti‐poverty impacts of irrigation? The paper offers insights into these questions with analyses and findings from our studies and with review and referencing of other related topical studies on the subject. Finally, the paper draws some generic lessons that could be useful in irrigation investment decisions. Copyright © 2007 John Wiley & Sons, Ltd.
Immune response against polyester implants is influenced by the coating substances
Authors: Wilhelm Lutz , Zippel Roland , von Woedtke Thomas , Kenk Heidrun , Hoene Andreas , Patrzyk Maciej , Schlosser Michael
Published: March 2007

The aim of this study was to evaluate the influence of the coating of polymer implants upon the individual humoral immune response to the polymer matrix. Intramuscular implantation and explantation of samples from three different polyester vascular prostheses coated with collagen, gelatin, or human serum albumin was performed in LEW.1A rats and subsequently compared to sham operated control animals. Antibodies in serum samples were detected by means of enzyme immunoassays employing particles of pure polyester and the respective prosthesis, or solid phase bound coating substances as targets. In contrast to the controls, all animals with implants demonstrated a high antipolyester antibody response with a broad individual variability graduated according to the prosthesis coatings: gelatin > albumin > collagen. This was further significantly increased after the second implantation/first explantation and declined following the last explantation. Only animals with albumin‐coated implants revealed specific antibodies to the coating as well as the strongest overall immunological reaction against the prosthesis already on day 8. Specificity of polymer antibodies was demonstrated by competitive inhibition of median antibody binding. Our results showed a specific immune reaction as a result of the applied polymer, which varied due to the surface‐coating and individual factors. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Reactive oxygen and nitrogen species: Implications for cardiovascular device engineering
Authors: Kader Khalid N. , Coyle Christian H.
Published: March 2007

The development of medical devices for cardiovascular applications has suffered due to lack of understanding of why vascular wall cells act nonphysiologically when exposed to biomaterials. One possible reason might be the chemical environment associated with cardiovascular disease. An improved understanding of cellular and subcellular mechanisms may assist in future device design to account for the disease environment. Reactive oxygen and nitrogen species (ROS/RNS) are produced through normal cellular metabolism and are rendered harmless by enzymatic systems. However, during a disease process, these systems may act aberrantly, and either fail to convert ROS and RNS to harmless substances or by producing more oxidants. There is indirect evidence that the implantation of biomedical materials may also be responsible for the triggering of these aberrant pathways that may lead to the eventual failure of the device. The understanding of how the vascular environment may be changed at the subcellular level by the presence of a biomaterial is critical. In the following pages, we hope to review the current thinking within vascular biology regarding ROS and RNS, how they are measured, and how they may impact vascular cells. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Comparative in vitro and in vivo studies using a bioactive poly(ε‐caprolactone)‐organosiloxane nanohybrid containing calcium salt
Authors: Yoo Jeong Joon , Lee Jong Eun , Kim Hee Joong , Kim Sug‐Jun , Lim Jung Hyun , Lee Seung Jin , Lee Jae Il , Lee Yong‐Keun , Lim Bum‐Soon , Rhee Sang‐Hoon
Published: March 2007

Comparative in vitro and in vivo studies were conducted using a bioactive poly(ε‐caprolactone)‐organosiloxane nanohybrid containing calcium, which was prepared by sol–gel method. The behavior of human bone marrow stromal cells (hBMSCs) during in vitro osteogenic differentiation were evaluated on poly(ε‐caprolactone)‐organosiloxane nanohybrid and poly(ε‐caprolactone)‐organosiloxane nanohybrid coated with apatite, which mimicked in vivo events. hBMSCs cultured on tissue culture plates (TCPs) were used as a control. For comparative studies, in vivo testing was also conducted using poly(ε‐caprolactone)‐organosiloxane nanohybrid and poly(ε‐caprolactone)‐organosiloxane nanohybrid coated with apatite in the diaphyseal bone defects of rabbit tibiae. Initial attachments and early proliferations of hBMSCs onto poly(ε‐caprolactone)‐organosiloxane with or without the apatite layer were comparable those onto TCPs. However, the late proliferation and the osteogenic differentiation activities on poly(ε‐caprolactone)‐organosiloxane nanohybrid were significantly lower than the hybrid coated with apatite or TCPs. These results were caused by the delayed detachment of hBMSCs induced by the upward growth of spire‐shaped apatite granules on the flat apatite layer through mixed nucleation (heterogeneous and homogeneous nucleation) and growth of apatite crystals during cell culture. However, the poly(ε‐caprolactone)‐organosiloxane nanohybrid showed excellent osteoconductivity as same as poly(ε‐caprolactone)‐organosiloxane nanohybrid coated with apatite in vivo even though the cell testing results in vitro were poor. This discrepancy can be explained by the difference in initial degree of supersaturation of apatite in cell culture medium and buffering ability between cell culture medium and body fluid with respect to calcium, which directly affects the nucleation mechanism of apatite crystals and the morphology of grown apatite granules. These findings imply that much attention is required and an optimal method should be used to assess cell responses in vitro. Our results suggest that precoating the apatite layer before in vitro testing is desirable for bioactive materials that release calcium quickly and in large amount because this treatment can more closely mimic in vivo events. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Hybrid titania–aminosilane platforms evaluated with human mesenchymal stem cells
Authors: Manso‐Silván M. , Rodríguez‐Navas C. , Arroyo‐Hernández M. , López‐Elvira E. , Gago R. , Vázquez L. , Agulló‐Rueda F. , Climent A. , Martínez‐Duart J. M. , García‐Ruiz J. P.
Published: March 2007

The properties of hybrid aminopropyltriethoxysilane–tetraisopropylorthotitanate (APTS‐TIPT) platforms prepared by a sol–gel route have been explored, and their biocompatibility was assayed after culture of human mesenchymal stem cells (hMSCs). The organic content of this material was observed to be preferably surface‐oriented as indicated by microanalytical techniques. Furthermore, the surface showed characteristic amino‐silane bands when explored by Raman spectroscopy as well as indications of silane and titanate condensation. Surface activity of the amino groups was probed by ultraviolet–visible spectroscopy imine derivatization and chemical force spectroscopy, showing a pH‐dependent surface charge‐induced potential. hMSCs cultured onto these surfaces showed relevant differences with respect to their behavior on gelatin‐coated glass plates. Even if with a lower proliferative rate than controls, the cells develop long cytosolic prolongations in osteogenic differentiation medium, thus, supporting the idea of an APTS‐TIPT stimulated process. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Initial cytotoxicity of novel titanium alloys
Authors: Koike M. , Lockwood P. E. , Wataha J. C. , Okabe T.
Published: March 2007

We assessed the biological response to several novel titanium alloys that have promising physical properties for biomedical applications. Four commercial titanium alloys [Super‐TIX® 800, Super‐TIX® 51AF, TIMETAL® 21SRx, and Ti‐6Al‐4V (ASTM grade 5)] and three experimental titanium alloys [Ti‐13Cr‐3Cu, Ti‐1.5Si and Ti‐1.5Si‐5Cu] were tested. Specimens (n = 6; 5.0 × 5.0 × 3.0 mm3) were cast in a centrifugal casting machine using a MgO‐based investment and polished to 600 grit, removing 250 μm from each surface. Commercially pure titanium (CP Ti: ASTM grade 2) and Teflon® (polytetrafluoroethylene) were used as positive controls. The specimens were cleaned and disinfected, and then each cleaned specimen was placed in direct contact with Balb/c 3T3 fibroblasts for 72 h. The cytotoxicity [succinic dehydrogenase (SDH) activity] of the extracts was assessed using the MTT method. Cytotoxicity of the metals tested was not statistically different compared to the CP Ti and Teflon® controls (p > 0.05). These novel titanium alloys pose cytotoxic risks no greater than many other commonly used alloys, including commercially pure titanium. The promising short‐term biocompatibility of these Ti alloys is probably due to their excellent corrosion resistance under static conditions, even in biological environments. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Development of self‐expandable covered stents
Authors: Sato Sachiko , Nakayama Yasuhide , Miura Yoshihiro , Okamoto Yoshihiro , Asano Hiroyuki , Ishibashi‐Ueda Hatsue , Zhou Yue‐Min , Hayashida Kyoko , Matsuhashi Toshio , Seiji Kazumasa , Sato Akihiro , Yamada Takayuki , Takahashi Shoki , Ishibashi Tadashi
Published: March 2007

We newly developed self‐expandable covered stents by combining two of our original technologies. Of these, the first is the dip‐coating covering method that was developed previously for balloon‐expandable stents; the other is the newly developed self‐expandable Nitinol stents, namely, Sendai stents. The three types of covered stents with the expansion diameter of 4.5, 5.0, or 6.0 mm thus obtained had a laser‐processed microporous elastomeric cover film (pore diameter: 100 μm, interpore distance: 250 μm). Although the film was extremely thin (∼15 μm), the film could be expanded without causing any damage, the strut was completely embedded within the film, and the luminal surface of the film was smooth and flat. Mechanical properties such as ideal flexibility to follow the shapes of arteries were almost retained even after covering. As appropriate drugs, the blood‐contacting inner and tissue‐contacting outer surfaces of the film were differentially coated with argatroban for antithrombogenicity or FK506 for anti‐inflammation, respectively. The preliminary in vivo study indicated that the covered stents mounted in the delivery catheter were navigated and placed to appropriate position in the arteries, and permissible neointimal thickening after 1‐month implantation was observed similarly in noncovered stents. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Certification in neuromuscular medicine: A new neurologic subspecialty
Authors: Aminoff Michael J. , Massey Janice M. , Scheiber Stephen C. , Juul Dorthea
Published: March 2007

Information is provided concerning the new subspecialty certificate in neuromuscular medicine of the American Board of Psychiatry and Neurology and the eligibility requirements for such certification of practicing neurologists and child neurologists. The Accreditation Council for Graduate Medical Education has approved fellowship training in the subspecialty, and it is likely that residents who wish to pursue a career in neuromuscular medicine will select this training option. Muscle Nerve 35: 409–410, 2007
Yielding of plates with hardening and large deformations
Authors: Eggers Hans , Kröplin Bernd
Published: March 2007

A mixed finite element technique is used to study the influence of yielding on buckled plates. Orthogonal anisotropic hardening is determined solely by a yield condition, which is introduced into a mixed functional for the elastic plate by Lagrange Multipliers. The Euler equations of the constrained functional include Prager's normality rule.

Numerical results are given for rectangular plates of different size calculated for various material properties.
NADPH oxidase is required for neutrophil‐dependent autoantibody‐induced tissue damage
Authors: Chiriac MT , Roesler J , Sindrilaru A , Scharffetter‐Kochanek K , Zillikens D , Sitaru C
Published: March 2007

The contribution of phagocyte‐derived reactive oxygen species to tissue injury in autoimmune inflammatory diseases is unclear. Here we report that granulocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase crucially contributes to tissue injury in experimental models of the antibody‐mediated autoimmune disease epidermolysis bullosa acquisita. Neutrophil cytosolic factor 1‐deficient mice lacking functional NADPH oxidase were resistant to skin blistering by the passive transfer of antibodies against type VII collagen. Pharmacological inhibition or deficiency of human NADPH oxidase abolished dermal‐epidermal separation caused by autoantibodies and granulocytes ex vivo. In addition, recruitment of granulocytes into the skin was required for tissue injury, as demonstrated by the resistance to experimental blistering of wild‐type mice depleted of neutrophils and of CD18‐deficient mice. Transfer of neutrophil cytosolic factor 1‐sufficient granulocytes into neutrophil cytosolic factor 1‐deficient mice demonstrated that granulocytes provide the NADPH oxidase required for tissue damage. Our findings identify granulocyte‐derived NADPH oxidase as a key molecular effector engaged by pathogenic autoantibodies and provide relevant targets for prevention of tissue damage in granulocyte‐mediated autoimmune diseases. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
A simple method for determining sol—gel transition temperatures in weak polymer jellies
Authors: Harrison M. A. , Morgan P. H. , Park G. S.
Published: March 2007

A simple method for determining sol‐gel transition temperatures in mechanically weak thermoreversible gels has been developed. Only 0–3 ml of gel is required and gels with a rigidity modulus as low as 100 dyne cm−2 can be used.
Infra‐red spectra of polyvinyl acetate and poly‐α, α', β‐trideuterovinyl acetate
Authors: Haken J. K. , Werner R. L.
Published: March 2007

The infra‐red spectrum of polyvinyl acetate has been studied from 4000 to 150 cm‐1 and a detailed assignment made. To assist with the assignments the partially deuterated polymer, poly‐α, α, β‐trideuterovinyl acetate, and a branched‐chain acetate have been synthesised and their spectra examined.
Polyborazylene oxides
Authors: Atkinson I. B. , Clapp D. B. , Currell B. R. , Flavell W.
Published: March 2007

The reactions of various B‐dichloro‐N‐triarylborazines with boiling N,N‐dimethylformamide (DMF), and DMF in the presence of dimethylamine have been shown to give condensation polymers of the polyborazylene oxide type. The degrees of polymerisation range in individual cases from about 2–25. The presence of one ortho substituent in the N‐aryl group causes the molecular weight to fall sharply, and polymerisation is completely inhibited in the presence of two ortho substituents. Reactions of several N‐triarylborazines with boiling DMF also gave polyborazylene oxide‐type polymers together with trimethylamine. The infra‐red spectra, and thermal and hydrolytic stability of the polymers have been investigated.
Molecular probe studies of crystallinity in polyethylene
Authors: Stein A. N. , Gray D. G. , Guillet J. E.
Published: March 2007

The molecular probe technique uses a standard gas chromatograph modified to obtain a printed digital record of retention time vs. column temperature to be obtained automatically. From this the observed specific retention time, Vg, can be calculated. If Vg is the theoretical value it can be deduced that: % Crystallinity = [1 − Vg/Vg′ ] × 100. Experimental results using Tenite 800 and Tenite 3310 polyethylene produced and sold by Eastman Chemical Products Inc., Kingsport, Tennessee, U.S.A. justify this equation.
Formation of polymer crystals during polymerisation
Authors: Iguchi M. , Kanetsuna H. , Kawai T.
Published: March 2007

The structures of the polymers obtained in various types of heterogeneous polymerisations have been studied together with the polymerisation kinetics. Examples of these are: fibres of polymethylene and polyethylene; nylon spherulites produced in the polymerisation of lactams; and extended chain crystals of polyoxyethylene. Solid‐state polymerisation is briefly discussed.
Supportive‐expressive group therapy for women with metastatic breast cancer: survival and psychosocial outcome from a randomized controlled trial
Authors: Kissane David W. , Grabsch Brenda , Clarke David M. , Smith Graeme C. , Love Anthony W. , Bloch Sidney , Snyder Raymond D. , Li Yuelin
Published: March 2007

Background: Mixed reports exist about the impact of supportive‐expressive group therapy (SEGT) on survival.

Methods: From 485 women with advanced breast cancer recruited between 1996–2002, 227 (47%) consented and were randomized within an average 10 months of cancer recurrence in a 2:1 ratio to intervention with 1 year or more of weekly SEGT plus three classes of relaxation therapy (147 women) or to control receiving three classes of relaxation therapy (80 women). The primary outcome was survival; psychosocial well‐being was appraised secondarily. Analysis was by intention‐to‐treat.

Results: SEGT did not prolong survival (median survival 24.0 months in SEGT and 18.3 in controls; univariate hazard ratio for death 0.92 [95% CI, 0.69–1.26]; multivariate hazard ratio, 1.06 [95% CI, 0.74–1.51]). Significant predictors of survival were treatment with chemotherapy and hormone therapy (p<0.001), visceral metastases (p<0.001) and advanced disease at first diagnosis (p<0.05). SEGT ameliorated and prevented new DSM‐IV depressive disorders (p = 0.002), reduced hopeless–helplessness (p = 0.004), trauma symptoms (p = 0.04) and improved social functioning (p = 0.03).

Conclusions: SEGT did not prolong survival. It improved quality of life, including treatment of and protection against depression. Copyright © 2007 John Wiley & Sons, Ltd.
Decision‐related uncertainties perceived by people with cancer—modelling the subject of shared decision making
Authors: Kasper Jürgen , Geiger Friedemann , Freiberger Saskia , Schmidt Angelika
Published: March 2007

Aim was to survey distinctive qualities of decision‐related uncertainty in cancer. Assessment of differential perception of uncertainties is a prerequisite for the study of cognitive coping as mediated by risk communication.

A theory building process was initiated. Using in‐depth interviews with cancer patients subjective representations of uncertainty associated with medical decisions were explored. Grounded theory techniques were applied to extract categories out of the interview material.

The qualitative process led to an eight‐dimensional model. Five raters achieved a Fleiss agreement coefficient of 0.61 attributing raw material from interviews to the categories. Patients expressed uncertainties concerning (1) disease‐related issues (prognosis/diagnosis, treatment), (2) risk communication issues (deciphering information, role in the medical dyad, physician's trustability) and (3) aspects of coping with life considering the disease (mastering requirements, social integration, causal attribution).

We found support for a multidimensional model of uncertainty. This approach can be helpful in the investigation of further issues concerning communication and coping with uncertainty related to medical decisions in cancer and other diseases. It sharpens shared decision making theoretically and thereby provides the basis for a measurement concept. Copyright © 2007 John Wiley & Sons, Ltd.
Amelioration of early cognitive deficits by aged garlic extract in Alzheimer's transgenic mice
Authors: Chauhan Neelima B. , Sandoval Jimena
Published: March 2007

Subtle accumulation of β‐amyloid peptide (Aβ) oligomers of Aβ42 species in particular, is known to correlate with cognitive deficits independent of Aβ plaque deposition in the brain. Majority of the research showing behavioral improvement after cerebral Aβ reduction has been reported when the animals carried fewer/abundant amyloid plaques in the brain. Very few studies have addressed whether or not behavioral deficits exist even at the pre‐plaque stage or in the absence of plaques that would parallel the mild cognitive impairment (MCI) stage of Alzheimer's disease (AD). Current study was undertaken to determine whether there exists any cognitive impairment during the pre‐plaque stage which may parallel the MCI stage of AD, and to confirm whether the observed behavioral deficits correlate with Aβ42 predominance. In addition, the study determined whether anti‐amyloidogenic effects of dietary aged garlic extract would prevent progressive behavioral impairment. For this purpose we used Tg2576 model showing slow plaque development with a predominance of Aβ40, and the TgCRND8 model showing accelerated plaque development with a predominance of Aβ42. The results show that at 2 months of age Tg2576 mice did not exhibit behavioral impairment in any of the tasks studied. While 2‐month‐old TgCRND8 mice displayed only a subtle behavioral deficit that matched the behavioral deficits observed in 7‐month‐old Tg2576 mice which may correlate with the MCI stage of AD. TgCRND8 mice at 7 months of age exhibited advanced deterioration in all behavioral tasks studied, suggesting that accelerated Aβ accumulation and the predominance of Aβ42 species may account for the pronounced cognitive deficits observed in TgCRND8. Feeding of aged garlic extract prevented deterioration of hippocampal based memory tasks in these mice, suggesting that aged garlic extract has a potential for preventing AD progression. Copyright © 2007 John Wiley & Sons, Ltd.
Reduction of mouth malodour and volatile sulphur compounds in intensive care patients using an essential oil mouthwash
Authors: Hur Myung‐Haeng , Park Joohyang , Maddock‐Jennings Wendy , Kim Dong Oak , Lee Myeong Soo
Published: March 2007

The aim of this study was to explore the effect of an essential oil solution on levels of malodour and production of volatile sulphur compounds (VSC) in patients nursed in intensive care unit (ICU). Thirty two patients received 3 min of oral cleaning using an essential oil solution (mixture of tea tree, Melaleuca alternifolia, peppermint, Mentha piperita and lemon, Citrus limon) on the first day, and Tantum (benzydamine hydrochloride) on the second day. Two trained nurses measured the level of malodour with a 10 cm visual analogue scale (VAS) and VSC with a Halimeter before (Pre), 5 min after (Post I) and 1 h following treatment (Post II). The level of oral malodour was significantly different following the essential oil session, and differed significantly between two sessions at Post I (p < 0.005) and Post II (p < 0.001). Differences between the two sessions were significant (Tantum, p < 0.001; essential oil, p < 0.001) in the level of VSC and significantly lower in the essential oil session than Tantum at the Post II (p < 0.05). These findings suggest that mouth care using an essential oil mixture of diluted tea tree, peppermint and lemon may be an effective method to reduce malodour and VSC in intensive care unit patients. Copyright © 2007 John Wiley & Sons, Ltd.
Non‐inferiority trial design for recurrent events
Authors: Cook Richard J. , Lee Ker‐Ai , Li Hongdan
Published: March 2007

We describe methods for designing non‐inferiority trials with recurrent event responses arising from mixed‐Poisson models. Sample size formulae are derived for trials in which treatment effects are expressed as relative rates and as absolute differences in cumulative mean functions at a particular time. Simulation studies are conducted to provide empirical validation of the frequency properties of the design and testing procedures under the null and alternative hypotheses using both mixed‐Poisson models and robust marginal methods. The robustness of the design to misspecification of the random effect distribution is also studied empirically. Sample size requirements based on the proposed method are contrasted with those from a design based on the time to the first event for a motivating study of patients with bone metastases at risk of skeletal complications. When the between‐patient heterogeneity in the event rate is small, there may be a considerable reduction in sample size with recurrent event outcomes. Copyright © 2007 John Wiley & Sons, Ltd.
Nanometer‐Sized Molybdenum–Iron Oxide Capsule‐Surface Modifications: External and Internal
Authors: Müller Achim , Bögge Hartmut , Sousa Filipa L. , Schmidtmann Marc , Kurth Dirk G. , Volkmer Dirk , van Slageren Joris , Dressel Martin , Kistler Melissa L. , Liu Tianbo
Published: March 2007

The cluster {(Mo)Mo5}12FeIII30 1 a present in compound 1 (cluster diameter ≈2.3 nm), which belongs to the family of nanoscale spherical porous {(Mo)Mo5}12{Linker}30 capsules that allow a new type of nanochemistry inside their cavities as well as unprecedented aggregation processes under gaseous, solution, and solid‐state conditions, is the starting material for the present investigation. In solution it reacts with LnCl3⋅nH2O (Ln=Ce, Pr) thereby replacing six FeIII ions with LnIII ions to form compounds 2 (Ce) and 3 (Pr). During metal‐cation exchange, some of the pentagonal {(Mo)Mo5O21(H2O)6}6− units, which are connected to the FeIII centers in 1 a, decompose, thus leading to a temporary capsule opening and uptake of the formed smaller molybdate units into the capsule cavities. In 2 and 3, the pentagonal units are connected via 24 FeIII and six LnIII‐type linkers/spacers representing together the capsule skeletons, which are structurally well‐defined in contrast to the capsule contents. The new capsules self‐associate into single‐layer blackberry‐type structures, thus extending the variety of these types of assemblies; the assembly process, that is, the size of the final species, can be controlled by the pH, which allows the generation of differently sized nanoparticles. Magnetic properties of the two new nanomaterials 2 and 3 are also determined.
Reduction of blood and liver cholesterol in the rat by straight and branched chain alkyl amines
Authors: Svoboda J. A. , Wrenn T. R. , Thompson M. J. , Weyant J. R. , Wood D. L. , Bitman J.
Published: March 2007

The activities of a branched chain and several straight chain amines (C12 to C18 chain length), and the azasteroid 25‐aza‐5α‐cholestane were compared with those of 20,25‐diazacholesterol dihydrochloride, which is a potent hypocholesterolemic agent in the rat. These amines and azasteroids inhibit the Δ24‐sterol reductase system in the tobacco hornworm,Manduca sexta (L.), and also block the conversion of C28 and C29 plant sterols to cholesterol, with a resulting accumulation of desmosterol. The effects of these compounds in the rat were determined on body weight gain, cholesterol, desmosterol, and lipid composition of blood, feces, liver, and epididymal fat pad weight. The two azasteroids and the branched chain amine, N,N‐dimethyl‐3, 7,11‐trimethyldodecanamine, had the greatest effect, reducing total plasma lipids and plasma sterols to approximately 40–50% of the levels in control rats and produced a concomitant increase in plasma and liver desmosterol. The branched chain dodecanamine caused a reduction in both feed consumption and body weight gain. The branched and straight chain dodecanamines also severely reduced epididymal fat pad weight. Our results demonstrate that the simple azasteroid, 25‐aza‐5α‐cholestane, is a more potent inhibitor of cholesterol biosynthesis than the diazasterol and that the Δ24‐sterol reductase system in a mammal can be inhibited by simple, nonsteroidal, acyclic amines.
Fatty acid composition at the 2‐position of ether‐linked and diacyl ethanolamine and choline phosphoglycerides of human brain tumors
Authors: Albert Daniel H. , Anderson Carl E.
Published: March 2007

The acyl composition of ethanolamine and choline phosphoglycerides from a series of human brain tumors was determined and compared to that of normal human gray matter. Six glioblastomas, one astrocytoma, one oligodendroglioma, and one meningioma were analyzed. The total fatty acid composition of ethanolamine phosphoglycerides generally had a higher percentage of 18∶1, 18∶2ω6, and 22∶5ω3 and a lower percentage of 22∶6ω3 than that of normal gray matter. Choline phosphoglycerides from the tumors also contained a higher than normal percentage of 18∶2ω6. Separate analysis of the acyl groups at the 2 position of the diacyl and ether‐linked components of the phosphoglycerides revealed that the diacyl component of ethanolamine phosphoglyceride from the tumors had lower than normal amount of 22∶6ω3 and a higher than normal amount of 18∶1 and 18∶2ω6. The acyl composition of ether‐linked ethanolamine phosphoglycerides genearally contained a higher percentage of 20∶4ω6 and a lower percentage of 18∶1 compared to the corresponding fraction from normal gray matter. The astrocytoma analyzed had fatty acid profiles similar to those of the control with the exception of a greater 18∶2ω6 content. These data demonstrate that the composition of the acyl moiety at the 2 position of diacyl and ether‐linked phosphoglycerides of brain tumors differs from the corresponding component from normal gray matter and that the ether‐linked ethanolamine phosphoglycerides provide an important pool of polyunsaturated fatty acids from brain tumor phospholipids.
Effect of substrate polarity on the activity of soybean lipoxygenase isoenzymes
Authors: Bild Gary S. , Ramadoss Candadai S. , Axelrod Bernard
Published: March 2007

In order to characterize the several isoenzymes of soybeans, they were examined with respect to the effect of the polar nature of the substrate. In general, lipoxygenase‐1 was most active when presented with charged substrates such as the anionic form of linoleic acid or of potassium linoleyl sulfate, whereas lipoxygenase‐2 and‐3 preferred nonpolar substrates such as unionized linoleic acid, methyl linoleate, linoleyl methane sulfonate, 10,13‐nonadecadieneamine, or linoleyl acetate. Linoleyl sulfate, which has been advanced as an excellent readily soluble substrate for lipoxygenase, was indeed the best substrate found for lipoxygenase‐1. Lipoxygenase‐2 and‐3 were, by contrast, totally inactive against this substrate. The favorable response of linnoleic acid to lipoxygenase‐2 and‐3 at pH 6.8 was ascribed to the anomalously high pKa value of linoleic acid compared to that of short chain carboxylic acids. The pH‐activity profile obtained with lipoxygenase acting on linoleyl sulfate (which was charged at all pH values examined) was shifted to lower pH values compared to the linoleic acid activity profile. The effect of changing from the charged to the uncharged substrate, when tested against lipoxygenase‐1, was to increase the Km by an order of magnitude.
Fatty acid composition of selected organs of gerbils maintained on a fat‐deficient or fat‐supplemented diet
Authors: Coniglio John G. , Harris D. G.
Published: March 2007

The fatty acid composition of liver, heart, and testes was determined in gerbils maintained on a fat‐deficient or fatsupplemented diet since the age of twenty‐eight days and in gerbil pups, the mothers of which were placed on the respective diets on the day of delivery. Pups born to these mothers were killed at 11 to 19 days at which time increased concentrations of 16∶1, 18∶1, and 20∶3ω9 and decreased concentrations of 18∶2 and 20∶4 (and 22∶5ω6 in testes) were apparent in organs of fat‐deficient compared to fat‐supplemented gerbils. Similar but more marked changes occurred in organs of gerbils placed on the fat‐deficient diet at twenty‐eight days of age and examined at intervals of time up to two months later. In these animals, minimal changes were seen also in fatty acids of the brain. The concentration of 22∶6ω3 was resistant to change with the fat‐deficient diet. Deficient gerbils had hair loss, decreased quantities of spermatids and spermatozoa in the testis, and most but not all had decreased body weight compared to the fat‐supplemented controls. Extremely high concentrations of oleic acid were present in carcass fatty acids of deficient compared to supplemented gerbils, indicating an extremely dynamic fatty acid metabolism in these animals.
Stereospecific synthesis ofcis andtrans fatty esters
Authors: Rakoff Henry , Emken Edward A.
Published: March 2007

Theerythro andthreo isomers of methyl 9,10‐dihydroxyoctadecanoate and thethreo isomer of methyl 12,13‐dihydroxy‐cis‐9‐octadecenoate were converted into methylcis‐ andtrans‐9‐octadecenoate and methylcis‐9,rans‐12‐octadecadienoate, respectively, by reaction of the dihydroxy ester with triethyl orthoformate to give the 2‐ethoxy‐1,3‐dioxolane which was thermally decomposed to the unsaturated ester.
Hydrogenation
Authors: Allen R. R.
Published: March 2007

Hydrogenation of vegetable oils as it is practiced today is described as theory and process. Double bonds in the fatty acid portions of the oils are saturated with hydrogen and rearranged to produce many isomers during the process.