bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Intramolecular Transfer to Polymer on Stationary Free Radical Polymerization of Alkyl Acrylates, 2
Authors: Nikitin Anatoly N. , Hutchinson Robin A.
Published: February 2006

Summary: Procedures are developed to estimate kinetic rate coefficients from available rate data for the free radical solution polymerization of butyl acrylate at 50 °C. The analysis is based upon a complete mechanistic set that includes the formation of mid‐chain radicals through backbiting and their subsequent reaction, and contains no assumptions on how the rate coefficient for cross‐termination of mid‐chain and end‐chain radicals is related to the two homo‐termination rate coefficients. After a thorough statistical analysis, the results of the fitting are combined with other recent literature data to provide a complete set of individual rate coefficients for the butyl acrylate system. Monomer addition to a mid‐chain radical is estimated to be slower than addition to a chain‐end radical by a factor of more than 400. The termination of two mid‐chain radicals is estimated to be two orders of magnitude slower than termination of two end‐chain radicals, with the cross‐termination rate coefficient close to the geometric mean.

Formation of a mid‐chain radical by intramolecular chain transfer to polymer by a chain‐end radical.

image

Formation of a mid‐chain radical by intramolecular chain transfer to polymer by a chain‐end radical.
On the principles of limiting absorption and limit amplitude for a class of locally perturbed waveguides. Part 1: Time‐independent theory
Authors: Morgenröther K. , Werner P.
Published: February 2006

Let Ω be a local perturbation of the n‐dimensional domain Ω0 = Ropf;n − 1 × (0, π). In a previous paper8 we have introduced the notion of an admissible standing wave. We shall prove that the principle of limiting absorption holds for the Dirichlet problem of the reduced wave equation in Ω at ω ≥ 0 if Ω does not allow admissible standing waves with frequency ω. From Reference 8, this condition is satisfied for every ω ≥ 0 if Ω ≠ Ω0, and v·x′ ≤ 0 on δΩ, where x′ = (x1,…, xn − 1, 0) and v is the normal unit vector on δΩ pointing into the complement of Ω. In contrast to this, the principle of limiting absorption is violated in the case of the unperturbed domain Ω0 at the frequencies ω = 1,2,… if n ≤ 3. The second part of our investigation, which will appear in a subsequent paper, is devoted to the principle of limit amplitude.
Numerical simulation of the separated fluid flows at large Reynolds numbers
Authors: Gushchin V. A. , Konshin V. N.
Published: February 2006

The variety of flow regimes (steady separated, periodically separated‐‘Karman vortex street’, unsteady turbulent) and their characteristic peculiarities (separation and reattachment points, secondary separation, boundary layer, instability of the shear mixing layer, etc.) require the construction of effective numerical methods, which will be able to simulate adequately the considered flows.

MERANGE  SMIF–a splitting method for physical factors of incompressible fluids1‐is used for calculations of the steady and unsteady fluid flows past a circular cylinder in a wide range of Reynolds numbers (10° < Re < lo6). The finite‐difference scheme for this method is of second order accuracy in the space variables, has minimal numerical viscosity and is also monotonic. Use of the Navier‐Stokes equations with the corresponding transformation of Cartesian co‐ordinates allows the calculations to be made by one algorithm both in a boundary layer and out of it. The method allows calculations at Re = ∞ cc and simulation of d‘Alembert’s paradox. Some results on the classical problem of the flow around a circular cylinder for a wide range of Reynolds numbers are discussed. The crisis of the total drag coefficient and the sharp rise of the Strouhal number are simulated numerically (without any turbulence models) for the critical Reynolds numbers (Re ≈ 4 × 105), and are in a good agreement with experimental data.
Higher‐order solutions of square driven cavity flow using a variable‐order multi‐grid method
Authors: Nishida Hidetoshi , Satofuka Nobuyuki
Published: February 2006

A new higher‐order method is devised for the numerical simulation of square driven cavity flows. The spatial derivatives of the Navier‐Stokes equations are discretized by means of the modified differential quadrature (MDQ) method. The resulting system of ordinary differential equations (ODEs) in time is then integrated by the classical fourth‐order Runge–Kutta–Gill (RKG) scheme. The elliptic (Poisson) equation is solved by means of a new variable‐order multi‐grid method. The numerical simulations of the square driven cavity flows are carried out with spatial order of accuracy up to 10th order. The results suggest that the higher‐order solutions are more reliable than the well‐known results obtained by Ghia et al.
On stable equal‐order finite element formulations for incompressible flow problems
Authors: Filho Jose Karam , Loula Abimael F. D.
Published: February 2006

In this work we discuss stable equal‐order finite element formulations for incompressible flow problems based on Petrov–Galerkin methods, constructed by adding to the classical Galerkin formulation least‐squares of the governing equations. Continuous and discontinuous pressure interpolations are considered. Numerical results are presented reinforcing the numerical analysis.
Semi‐implicit and explicit finite element schemes for coupled fluid/thermal problems
Authors: Ramaswamy B. , Jue T. C. , Akin J. E.
Published: February 2006

A comparative investigation, based on a series of numerical tests, of two purely explicit and one semi‐implicit finite element methods used for incompressible flow computation is presented. The ‘segregated’ approach is followed and the equations of motion are considered sequentially. The fundamental concepts and characteristics of the formulations and the solution methodology used are described in technical detail. Various modifications to Chorin's projection algorithm are investigated, particularly with respect to their effects on stability and accuracy. The stability of the semi‐implicit method is shown to be less restrictive when compared to the explicit methods as the Reynolds number increases. At large time steps the artificial viscosity is also reduced and higher accuracy is obtained. The performance of the methods discussed in this paper is illustrated by the numerical solutions obtained for the cavity flow and flow past a rearward‐facing step problems at high Reynolds numbers, and free convection flow problem at high Rayleigh numbers. It is shown that the semi‐implicit method needs fewer iterations than the explicit methods, and the accuracy of the present methods is guaranteed by comparison with the existing methods.
Experimental paracetamol‐induced hepatic necrosis: A histopathological study
Authors: Dixon M. F. , Nimmo J. , Prescott L. F.
Published: February 2006

HEPATIC necrosis resulting from massive overdosage with paracetamol (N‐acetyl‐p‐aminophenol, acetaminophen, APAP) was first reported in rats by Boyd and Bereczky in 1966. A report of this complication in man soon followed (Davidson and Eastham, 1966) and a total of 12 such cases have now been reported (Thomson and Prescott, 1966; Maclean et at., 1968; Pimstone and Uys, 1968; Rose, 1969; Toghill et al., 1969). Whilst Boyd and Bereczky were mainly concerned with acute oral toxicity, they summarised the histopathological findings in a large number of tissues and gave a brief description of the histological changes in the liver. There has not been a detailed histopathological study of paracetamol‐induced liver necrosis, nor has the natural course of the lesion been adequately described. The main objective of the present study was to provide such information by examining the changes in the livers of rats killed at various intervals after administration of a single large dose of paracetamol.
An unusual lesion in the pig aorta
Authors: Woolf N. , Robertson W. B.
Published: February 2006

SPONTANEOUS atherosclerosis in the pig corresponds in many respects to the human disease and has been well described by several authors (Gottlieb and Lalich, 1954; Jennings et al., 1961); the process of organisation of mural thrombus in the pig's blood vessels has also been recorded (Jørgensen et al., 1967; Woolf et al., 1968). The naturally occurring lesion we describe here does not appear to fall readily into either category; it has been noted in the pig aorta by other workers (Bragdon, Zeller and Stevenson, 1957; French, Jennings and Florey, 1965; Gupta, Tandon and Ramalingaswami, 1969).

This lesion is, in our experience, confined to the thoracic aorta; it is small, 2–3 mm in diameter, round or oval, glistening and dome‐shaped; and as we thought it had the appearance of a droplet on a non‐wettable surface we have called it the “droplet lesion”.
Flow and cure phenomena in liquid composite molding
Authors: Kendall K. N. , Rudd C. D.
Published: February 2006

Liquid molding processes including resin transfer molding (RTM) and structural reaction injection molding (SRIM) continue to attract attention due to their potential for high volume manufacture. This paper examines and compares the pressuare and temperature histories observed in mold cavities during impregnation, heating, and polymerization for both RTM and SRIM using polyester, vinyl ester, and polyurethane resins in combination with continuous strand mats. Experimental results are related to thermal, chemical and rheological effects. Factors which influence materials behavior and process control and the implications for mold design are discussed.
Influence of fiber length, fiber orientation, and interfacial adhesion on poly (butylene terephthalate)/polyethylene alloys reinforced with short glass fibers
Authors: Joshi M. , Maiti S. N. , Misra A. , Mittal R. K.
Published: February 2006

Blends of poly(butylene terephthalate) and high density polyethylene at a ratio of 80:20 wt% were reinforced with short glass fibers varying from 10 to 30 wt% to enhance mechanical properties. Considerable fiber damage occurred during injection molding, reducing the number average fiber length from the starting value of 4.5 mm to < 1 mm. This value decreased with increasing fiber content, which is also responsible for lowering the reinforcement efficiency. The variation in mechanical properties has been explained on the basis of fiber concertration. The effect of an ionomer, which was used to compatibilize the blends, on properties of corresponding composites has also been studied.
Screw plasticating of discontinuous fiber filled thermoplastic: Mechanisms and prevention of fiber attrition
Authors: Wolf H. J.
Published: February 2006

Processing of fiber compounds in single‐screw plasticating units can cause fiber fracture. Attempts have been made to obtain large residual fiber length in finished components. Therefore, pultrusion compounded materials for extrusion and injection molding have been developed. Pellets chopped from pultruded strands, containing perfectly wetted fibers of uniform length, eliminate the need for the mixing operation in an extrusion compounder. The attempt to preserve the initial fiber length during processing reised interest in the origin of fiber attrition and in optimized processing parameters. Based upon the knowledge that fiber length breakdown takes place mainly during the process of screw plasticating, extrusion trials have been carried out under varied conditions. Fiber length distrubutions and fiber movement within the cross sections of the screw channel along the screw axis have been investigated. It has been shown that screw speed. Pressure and barrel temperature profile, in dependence on screw geometry, show a distinct influence on the residual fiber length. This information provides a description of the prevailing fiber attrition mechanisms and helps define the most suitable hardware and the corresponding adjustment of process parameters to preserve large residual fiber length.
A systematic review of NSAIDs withdrawn from the market due to hepatotoxicity: lessons learned from the bromfenac experience
Authors: Goldkind Lawrence , Laine Loren
Published: February 2006

Drug‐induced hepatotoxicity is the leading cause of acute liver failure (ALF) in the US and the most common adverse event causing drug non‐approval and drug withdrawal by the U.S. Food and Drug Administration (FDA). Three different nonsteroidal anti‐inflammatory drugs (NSAIDs) have been withdrawn in the UK and/or the US due to hepatotoxicity (bromfenac, ibufenac, and benoxaprofen). A systematic review of clinical trials data for these drugs was performed in an effort to identify possible early signals that could have predicted post‐marketing serious hepatoxicity. There were very limited published data on benoxaprofen and none on ibufenac or bromfenac. The publicly accessible archives of the FDA provided information on bromfenac. Flu‐like symptoms associated with hepatic enzyme elevation and a case of possible drug‐related hepatocellular jaundice may in retrospect have been signals for serious hepatotoxicity in the database of 1195 subjects reviewed by the FDA. Following approval, rates of acute liver failure for bromfenac were estimated to be in the range of 1:10 000.

In addition, the safety databases of several drugs also accessed through FDA archives have been reviewed (simvastatin, tacrine, troglitazone, and ximelagatran). These data suggest that while ALT elevations alone do not reliably signal serious hepatotoxicity, elevated transaminases in association with symptomatic hepatitis or jaundice may be predictors of an increased risk of ALF. At present, however, pre‐approval databases are generally not large enough to rule out low rates of serious hepatotoxicity. Therefore, it remains critical that clinicians report such cases to the FDA through the MEDWATCH system and that active post‐marketing monitoring studies be used to identify potential rare cases of hepatotoxicity. Copyright © 2006 John Wiley & Sons, Ltd.
Achilles tendon rupture and its association with fluoroquinolone antibiotics and other potential risk factors in a managed care population
Authors: Seeger John D. , West William A. , Fife Daniel , Noel Gary J. , Johnson Larry N. , Walker Alexander M.
Published: February 2006

Background

Case reports and observational studies have implicated fluoroquinolone antibiotic exposure as a risk factor for Achilles tendon rupture (ATR), an uncommon condition for which there are few formal studies. We sought to quantify the strength of association between exposure to fluoroquinolone antibiotics and the occurrence of ATR, accounting for other risk factors.

Methods

This was a case‐control study nested within a health insurer cohort. Cases of ATR were identified and confirmed using patterns of health insurance claims that were validated through sampled medical record review. Information on risk factors, including fluoroquinolone exposure, came from health insurance claims.

Results

There were 947 cases of ATR and 18 940 controls. A dispensing of a fluoroquinolone antibiotic in the past 6 months was more common among ATR cases than controls, although not significantly so (odds ratio (OR) = 1.2; 95% confidence interval (CI) = 0.9–1.7), and exposure to a higher cumulative fluoroquinolone dose was more strongly associated (OR = 1.5, 95%CI = 1.0–2.3). Other risk factors for ATR were trauma (OR = 17.2, 95%CI = 14.0–20.2), male sex (OR = 3.0, 95%CI = 2.6–3.5), injected corticosteroid administration (OR = 2.2, 95%CI = 1.6–2.9), obesity (OR = 2.0, 95%CI = 1.2–3.1), rheumatoid arthritis (OR = 1.9, 95%CI = 1.0–3.7), skin or soft tissue infections (OR = 1.5, 95%CI = 0.9–2.3), oral corticosteroids (OR = 1.4, 95%CI = 1.0–1.8), and non‐fluoroquinolone antibiotics (OR = 1.2, 95%CI = 1.1–1.5).

Conclusions

The elevation in ATR risk associated with fluoroquinolones was similar in magnitude to that associated with oral corticosteroids or non‐fluoroquinolone antibiotics. Trauma and male sex were more strongly associated with ATR, as were obesity and injected corticosteroids. Copyright © 2006 John Wiley & Sons, Ltd.
Outer membrane vesicles from group B Neisseria meningitidis Δgna33 mutant: Proteomic and immunological comparison with detergent‐derived outer membrane vesicles
Authors: Ferrari Germano , Garaguso Ignazio , Adu‐Bobie Jeannette , Doro Francesco , Taddei Anna Rita , Biolchi Alessia , Brunelli Brunella , Giuliani Marzia Monica , Pizza Mariagrazia , Norais Nathalie , Grandi Guido
Published: February 2006

We compared the proteome of detergent‐derived group B Neisseria meningitidis (MenB) outer membrane vesicles (DOMVs) with the proteome of outer membrane vesicles (m‐OMVs) spontaneously released into culture supernatant by MenB Δgna33, a mutant in which the gene coding for a lytic transglycosylase homologous to the E. coli MltA was deleted. In total, 138 proteins were identified in DOMVs by 1‐ and 2‐DE coupled with MS; 64% of these proteins belonged to the inner membrane and cytoplasmic compartments. By contrast, most of the 60 proteins of m‐OMVs were classified by PSORT as outer membrane proteins. When tested for their capacity to elicit bactericidal antibodies, m‐OMVs elicited a broad protective activity against a large panel of MenB strains. Therefore, the identification of mutations capable of conferring an OMV‐releasing phenotype in bacteria may represent an attractive approach to study bacterial membrane composition and organization, and to design new efficacious vaccine formulations.
Reduction of proteins during sample preparation and two‐dimensional gel electrophoresis of woody plant samples
Authors: Vâlcu Cristina‐Maria , Schlink Katja
Published: February 2006

Protein extraction procedure and the reducing agent content (DTT, dithioerythritol, tributyl phosphine and tris (2‐carboxyethyl) phosphine (TCEP)) of the sample and rehydration buffers were optimised for European beech leaves and roots and Norway spruce needles. Optimal extraction was achieved with 100 mM DTT for leaves and needles and a mixture of 2 mM TCEP and 50 mM DTT for roots. Performing IEF in buffers containing hydroxyethyldisulphide significantly enhanced the quality of separation for all proteins except for acidic root proteins, which were optimally focused in the same buffer as extracted.
Proteomic and biochemical analyses of in vitro carcinogen‐induced lung cell transformation: Synergism between arsenic and benzo[a]pyrene
Authors: Lau Andy T. Y. , Chiu Jen‐Fu
Published: February 2006

Chronic coexposures to carcinogens inorganic arsenic and benzo[a]pyrene (B[a]P) are common in the living environment. However, little is known about their effects exerted at the proteome level. Our previous study in rat lung epithelial cells showed that cell transformation frequency increased by more than 100‐fold when arsenic was given in combination with B[a]P than cells either exposed to arsenic or B[a]P alone. This demonstrated a synergism between them. Here, we reported that alterations to the proteome varied and were more pronounced in the transformed cells that were exposed to a combination of arsenic and B[a]P than to B[a]P and much less to arsenic alone when compared to passage‐matched control cells. In general, three proteins belonging to intermediate filaments were found to be significantly down‐regulated and six proteins belonging to antioxidative stress‐, chaperone‐, and glycolytic proteins were up‐regulated in these transformed cells. These transformed cells were also associated with an increase of proliferation and de‐differentiation. Taken together, our findings suggest that although arsenic or B[a]P alone is sufficient to induce cell transformation and alter the proteome to a similar extent, the effects of coexposure are much more pronounced. This further substantiates the notion that these carcinogens act in concert during cocarcinogenesis.
Proteomic analysis reveals a novel role for the actin cytoskeleton in vincristine resistant childhood leukemia – An in vivo study
Authors: Verrills Nicole M. , Liem Natalia L. , Liaw Tracy Y. E. , Hood Brian D. , Lock Richard B. , Kavallaris Maria
Published: February 2006

Intrinsic or acquired resistance to vincristine (VCR), an antimicrotubule agent used in the treatment of childhood acute lymphoblastic leukemia (ALL), is a major clinical problem. Using a clinically relevant NOD/SCID mouse xenograft model of ALL, we established that alterations in the actin and tubulin cytoskeleton are involved in in vivo VCR resistance. Altered protein expression between VCR‐sensitive ALL xenografts, and xenografts with intrinsic or acquired VCR resistance, was identified using 2‐D DIGE coupled with MS. Of the 19 proteins displaying altered expression, 11 are associated with the actin cytoskeleton. Altered expression of the actin‐ and/or tubulin‐binding proteins gelsolin, moesin, ezrin, tropomyosin, CAP‐G, HSP27, HSP70, TCP‐1, and stathmin were associated with in vivo VCR resistance. The actin‐regulating protein gelsolin was increased in both acquired and resistant leukemia as confirmed by immunoblotting and gene expression. The major cytoskeletal protein, γ‐actin, was down‐regulated in the VCR‐resistant leukemia xenografts; in contrast, there was no significant change in β‐actin expression. This study provides the first evidence for a role of the actin cytoskeleton in intrinsic and acquired in vivo antimicrotubule drug resistance in childhood leukemia and highlights the power of 2‐D DIGE for the discovery of resistance markers, pharmacoproteomics, and signaling pathways in cancer.
Synthesis, characterization, effect of architecture on crystallization, and spherulitic growth of poly(L‐lactide)‐b‐poly(ethylene oxide) copolymers with different branch arms
Authors: Cai Chen , Wang Lu , Dong Chang‐Ming
Published: February 2006

Well‐defined poly(L‐lactide)‐b‐poly(ethylene oxide) (PLLA‐b‐PEO) copolymers with different branch arms were synthesized via the controlled ring‐opening polymerization of L‐lactide followed by a coupling reaction with carboxyl‐terminated poly(ethylene oxide) (PEO); these copolymers included both star‐shaped copolymers having four arms (4sPLLA‐b‐PEO) and six arms (6sPLLA‐b‐PEO) and linear analogues having one arm (LPLLA‐b‐PEO) and two arms (2LPLLA‐b‐PEO). The maximal melting point, cold‐crystallization temperature, and degree of crystallinity (Xc) of the poly(L‐lactide) (PLLA) block within PLLA‐b‐PEO decreased as the branch arm number increased, whereas Xc of the PEO block within the copolymers inversely increased. This was mainly attributed to the relatively decreasing arm length ratio of PLLA to PEO, which resulted in various PLLA crystallization effects restricting the PEO block. These results indicated that both the PLLA and PEO blocks within the block copolymers mutually influenced each other, and the crystallization of both the PLLA and PEO blocks within the PLLA‐b‐PEO copolymers could be adjusted through both the branch arm number and the arm length of each block. Moreover, the spherulitic growth rate (G) decreased as the branch arm number increased: G6sPLLA‐b‐PEO < G4sPLLA‐b‐PEO < G2LPLLA‐b‐PEO < GLPLLA‐b‐PEO. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2034–2044, 2006
Phase behavior, crystallization, and nanostructures in thermoset blends of epoxy resin and amphiphilic star‐shaped block copolymers
Authors: Guo Qipeng , Wang Ke , Chen Ling , Zheng Sixun , Halley Peter J.
Published: February 2006

This article reports thermoset blends of bisphenol A‐type epoxy resin (ER) and two amphiphilic four‐arm star‐shaped diblock copolymers based on hydrophilic poly(ethylene oxide) (PEO) and hydrophobic poly(propylene oxide) (PPO). 4,4′‐Methylenedianiline (MDA) was used as a curing agent. The first star‐shaped diblock copolymer with 70 wt % ethylene oxide (EO), denoted as (PPO‐PEO)4, consists of four PPO‐PEO diblock arms with PPO blocks attached on an ethylenediamine core; the second one with 40 wt % EO, denoted as (PEO‐PPO)4, contains four PEO‐PPO diblock arms with PEO blocks attached on an ethylenediamine core. The phase behavior, crystallization, and nanoscale structures were investigated by differential scanning calorimetry, transmission electron microscopy, and small‐angle X‐ray scattering. It was found that the MDA‐cured ER/(PPO‐PEO)4 blends are not macroscopically phase‐separated over the entire blend composition range. There exist, however, two microphases in the ER/(PPO‐PEO)4 blends. The PPO blocks form a separated microphase, whereas the ER and the PEO blocks, which are miscible, form another microphase. The ER/(PPO‐PEO)4 blends show composition‐dependent nanostructures on the order of 10−30 nm. The 80/20 ER/(PPO‐PEO)4 blend displays spherical PPO micelles uniformly dispersed in a continuous ER‐rich matrix. The 60/40 ER/(PPO‐PEO)4 blend displays a combined morphology of worm‐like micelles and spherical micelles with characteristic of a bicontinuous microphase structure. Macroscopic phase separation took place in the MDA‐cured ER/(PEO‐PPO)4 blends. The MDA‐cured ER/(PEO‐PPO)4 blends with (PEO‐PPO)4 content up to 50 wt % exhibit phase‐separated structures on the order of 0.5–1 μm. This can be considered to be due to the different EO content and block sequence of the (PEO‐PPO)4 copolymer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 975–985, 2006
Thermo‐hygro‐mechanical behavior of spider dragline silk: Glassy and rubbery states
Authors: Plaza Gustavo R. , Guinea Gustavo V. , Pérez‐Rigueiro José , Elices Manuel
Published: February 2006

Spider silk is considered as the basis of a new family of high performance fibers that would reproduce the excellent mechanical properties of the silk, in particular its extreme toughness. However, it has been observed that the mechanical properties of spider silk are severely influenced by humid environments that give rise to significant decreases in its length and elastic modulus. The change from stiff to compliant tensile properties is associated with the glass transition from a glassy to a rubbery state; here, we have found that it depends on both temperature and relative humidity. The glass transition was identified at different temperatures and relative humidities by monitoring the variation of the elastic modulus and observing the emergence of supercontraction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 994–999, 2006
Effect of molecular size on cooperative dynamics of low mass compounds in polystyrene
Authors: Urakawa O. , Ohta E. , Hori H. , Adachi K.
Published: February 2006

We studied the dielectric relaxation behavior of low mass compounds (LMC) mixed in polystyrene (PS). Specifically, LMCs that are used are alkyl‐cyanobenzene (nCBz, n = 0), alkyl‐cyanobiphenyl (nCB, n = 0, 1, 3, 5, and 7), and alkyl‐cyanoterphenyl (nCT, n = 5), where n represents the number of carbon atoms of the normal alkyl groups of the LMCs. Owing to a much larger dipole moment of the cyano group than that of PS, only motions of the LMCs were observed. In a blend of 5CT (5 wt %)/PS, single relaxation process designated as α was observed. On the other hand, in nCB (5 wt %)/PS, partially overlapped two relaxation processes (α and β) were observed in the order of decreasing temperature. We assigned the α process to cooperative motions between the LMC molecules and the PS segments, and the β process to spatially restricted motions of the LMC molecules in the glassy state. In 0CBz (8 wt %)/PS, the α and β processes were observed in distinct temperature regions and the intensity of the α peak was comparable to that of pure PS, indicating that the 0CBz molecules do not move cooperatively with the PS segments. We conclude the existence of two critical sizes (I and II) of LMC in relation to cooperativity: when an LMC molecule is smaller than the size‐I, the motions of the LMCs and PS segments decouple each other, but above the size‐I, they become cooperative. Above the size‐II, the spatially restricted motion (β‐process) of LMC does not occur. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 967–974, 2006
Status of search for supersymmetry
Authors: Bethke S.
Published: February 2006

A brief overview of the current status and of future perspectives of searches for Supersymmetry is given.
Effective supergravity from the weakly coupled heterotic string
Authors: Gaillard M.K.
Published: February 2006

The motivation for Calabi‐Yau‐like compactifications of the weakly coupled E8 ⊗ E8 heterotic string theory, its particle spectrum and the issue of dilaton stabilization are briefly reviewed. Modular invariant models for hidden sector condensation and supersymmetry breaking are described at the quantum level of the effective field theory. Their phenomenological and cosmological implications, including a possible origin for R‐parity, are discussed.
Thermodynamical properties of some coset CFT backgrounds
Authors: Giveon A. , Konechny A. , Rabinovici E. , Sever A.
Published: February 2006

We investigate the thermodynamical features of two Lorentzian signature backgrounds that arise in string theory as exact CFTs and possess more than two disconnected asymptotic regions: the 2‐d charged black hole and the Nappi‐Witten cosmological model. We find multiple smooth disconnected Euclidean versions of the charged black hole background. They are characterized by different temperatures and electro‐chemical potentials. We find that there is no straightforward analog of the Hartle‐Hawking state that would express these thermodynamical features. We also obtain multiple Euclidean versions of the Nappi‐Witten cosmological model and study their singularity structure. It suggests to associate a non‐isotropic temperature with this background.
Supersymmetric models for fermions on a lattice
Authors: Ilieva N. , Narnhofer H. , Thirring W.
Published: February 2006

We investigate the large‐N behaviour of simple examples of supersymmetric interactions for fermions on a lattice. Witten's supersymmetric quantum mechanics and the BCS model appear just as two different aspects of one and the same model. For the BCS model, supersymmetry is only respected in a coherent superposition of Bogoliubov states. In this coherent superposition mesoscopic observables show better stability properties than in a Bogoliubov state.
Noncommutative field theory
Authors: Schupp P.
Published: February 2006

This lecture in honor of Julius Wess on the occasion of his seventieth birthday provides an introductory overview of noncommutative field theory in the approach pioneered by himself.
Supersymmetry Then and Now
Authors: Zumino B.
Published: February 2006

A brief description of some salient aspects of four‐dimensional supersymmetry: early history, supermanifolds, the MSSM, cold dark matter, the cosmological constant and the string landscape.
Compactifications on generalized geometries
Authors: Louis J.
Published: February 2006

We discuss compactifications on generalized geometries and their role as mirror configurations of compactifications with background fluxes.
Solution structure and binding specificity of FBP11/HYPA WW domain as Group‐II/III
Authors: Kato Yusuke , Hino Yumi , Nagata Koji , Tanokura Masaru
Published: February 2006

The Group‐II/III WW domains bind Pro‐rich sequences, the most frequent protein motif found in eucaryotic genomes. We have proposed that the Group‐II and ‐III WW domains be merged into a larger group because the members of each group have relatively wide specificity and bind to the common ligands [Kato et al., J Biol Chem 2004;279:31833–31841]. We have also proposed that Group‐II/III has a common surface patch, the XP2 groove, to bind the ligands. The first WW domain of FBP11/HYPA is one of the Group‐II/III WW domains. The solution structure of the 26 residue‐long converged region exhibits an antiparallel triple stranded β‐sheet with a small hydrophobic core. The WW domain of FBP11/HYPA has both XP and XP2 grooves on its surface. Ligand titration by 1H15N HSQC NMR spectra revealed that the WW domain of FBP11/HYPA binds all the peptides with the PL, PP, and PR motifs. The profile patterns of chemical shift perturbation were quite similar among the spectra titrated with all three ligands. In addition, the titration significantly shifts the signals of the residues that compose the XP2 groove. All these findings suggest the functional importance of the XP2 groove and group definition of Group‐II/III of the WW domains. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Structural and thermodynamic consequences of removal of a conserved disulfide bond from equine β‐lactoglobulin
Authors: Yamada Yoshiteru , Nakagawa Kanako , Yajima Takeo , Saito Keiko , Tokushima Akihito , Fujiwara Kazuo , Ikeguchi Masamichi
Published: February 2006

A disulfide bond between cysteine 66 and cysteine 160 of equine β‐lactoglobulin was removed by substituting cysteine residues with alanine. This disulfide bond is conserved across the lipocalin family. The conformation and stability of the disulfide‐deleted mutant protein was investigated by circular dichroism. The mutant protein assumes a native‐like structure under physiological conditions and assumes a helix‐rich molten globule structure at acid pH or at moderate concentrations of urea as the wild‐type protein does. The urea‐induced unfolding experiment shows that the stability of the native conformation was reduced but that of the molten globule intermediate is not significantly changed at pH 4 by removal of the disulfide bond. On the other hand, the molten globule at acid pH was destabilized by removal of the disulfide bond. This difference in the stabilizing effect of the disulfide bond was interpreted by the effect of the disulfide in keeping the molecule compact against the electrostatic repulsion at acid pH. In contrast to the wild‐type protein, the circular dichroism spectrum in the molten globule state at acid pH depends on anion concentration, suggesting that the expansion of the molecule through electrostatic repulsion induces α‐helices as observed in the cold denatured state of the wild‐type protein. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Robotic whole body stereotactic radiosurgery: clinical advantages of the Cyberknife®integrated system
Authors: Coste‐Manière È , Olender D , Kilby W , Schulz R A
Published: February 2006

Radiosurgery is defined as the delivery of high doses of ionising radiation, in mono‐ or hypo‐ fractionated treatments, to destroy tumours or focal areas of pathology. The clinical requirements of designing a radiosurgical treatment system include providing: a) a highly precise beam delivery to targets located throughout the body, b) a highly conformal dose distribution, c) the ability to irradiate both small and/or large complex‐shaped lesions while minimising the dose to adjacent radiosensitive tissues and d) the ability to interactively track lesion motion due to normal patient motion. To accomplish this, the CyberKnife®radiosurgery system has pioneered in this area by taking advantage of the inherent geometrical targeting precision of a commercial arm‐based robotic system carrying a compact X‐band linear accelerator and integrated with X‐ray imaging and visualisation feedback systems. The arm‐mounted linear accelerator, equipped with patient specific anatomical models, registered to the patient in real‐time with image guidance, dynamically and safely delivers conformal and homogeneous radiation for therapeutic benefit. This paper details the components of the CyberKnife system and their integration in the clinical workflow of radiosurgery. Copyright © 2005 Robotic Publications, Ltd.
Precision placement of instruments for minimally invasive procedures using a “needle driver” robot
Authors: Cleary K , Watson V , Lindisch D , Taylor R H , Fichtinger G , Xu S , White C S , Donlon J , Taylor M , Patriciu A , Mazilu D , Stoianovici D
Published: February 2006

Medical practice continues to move toward less invasive procedures. Many of these procedures require the precision placement of a needle in the anatomy. Over the past several years, our research team has been investigating the use of a robotic needle driver to assist the physician in this task. This paper summarizes our work in this area. The robotic system is briefly described, followed by a description of a clinical trial in spinal nerve blockade. The robot was used under joystick control to place a 22 gauge needle in the spines of 10 patients using fluoroscopic imaging. The results were equivalent to the current manual procedure. We next describe our follow‐up clinical application in lung biopsy for lung cancer screening under CT fluoroscopy. The system concept is discussed and the results of a phantom study are presented. A start‐up company named ImageGuide has recently been formed to commercialize the robot. Their revised robot design is presented, along with plans to install a ceiling‐mounted version of the robot in the CT fluoroscopy suite at Georgetown University. Copyright © 2005 Robotic Publications Ltd.
Distinctive Sorghum Starch Granule Morphologies Appear to Improve Raw Starch Digestibility
Authors: Benmoussa Mustapha , Suhendra Budhi , Aboubacar Adam , Hamaker Bruce R.
Published: February 2006

Various factors, including starch granule channels, have been suggested to contribute to the control of sorghum starch digestibility for animal feed. Isolated starch from two normal sorghum lines (P721N, IS6986) and one high protein digestibility (HPD) mutant line (111) that differed in starch granule morphology were selected to study the influence of these factors on starch digestibility. Scanning electron micrographs were taken of raw and digested starches. Microscopy results confirmed that in all three sorghum lines channels in starch granules are the main route of enzyme penetration and the central cavity area is the starting point of enzyme digestion. Channel density was more pronounced in the HPD sorghum mutant line than in normal lines, which may have been responsible for its relatively high digestibility. Micrographs of IS6986 showed unique starch granule morphology with a collapsed ”doughnut‐shaped” structure in a portion of the granules. These unusual granules were rapidly digested and, unlike normal spherical granules, totally disappeared after 30 min of digestion. Amylases appeared to have fast access to the collapsed‐appearing starch granules. Digestion profiles, following incubation with pepsin and α‐amylase, showed that IS6986 and the HPD mutant (111) had the highest initial rate of starch digestion, followed by P721N. These findings provide insight as to how new sorghum cultivars might be developed with high starch digestibility for animal feed use.
Influence of Jet‐Cooking Temperature and Ionic Strength on Size and Structure of Cationic Potato Amylopectin Starch as Measured by Asymmetrical Flow Field‐Flow Fractionation Multi‐Angle Light Scattering
Authors: Modig Gustaf , Nilsson Per‐Ola , Wahlund Karl‐Gustav
Published: February 2006

Asymmetrical flow field‐flow fractionation (AsFlFFF) in combination with multi‐angle light scattering (MALS) was applied to cationic potato amylopectin (CPAP) to investigate how molar mass, root‐mean‐square (r.m.s.) radius and shape was influenced by different conditions of jet‐cooking. The effect of different jet‐cooking temperatures in the range 110°C – 140°C was studied in an excess steam jet‐cooker. This equipment is used in the industry for dissolution of starch and starch derivatives before technical application. The effect of different ionic strengths conditions was examined in the range of 10–200 mM. The weight‐average molar mass decreased from about 34×107 g/mol to 2.6×107 g/mol when the jet‐cooking temperature was increased from 110°C to 140°C. Concurrently the root‐mean‐square radius decreased from ca 380 nm to 90 nm. The decrease in size was reflected by a decrease in viscosity with increasing temperature. The root‐mean‐square radius was reduced when increasing the ionic strength. This decrease in size was correlated with a decrease in viscosity. Conformation and Kratky plots showed that at low ionic strength (≤ 10 mM) CPAP behaved as a flexible chain with high degree of branching, close to hyperbranching. Increase of the ionic strength gave a more compact structure and changes in the internal structure were observed as well. Consequently, by using AsFlFFF – MALS the effect of technical processing on the molar mass, molecular radius, conformational structure, and shape could be determined in a size region where standard methodology commonly fails.
Preparation and Properties of Octenyl Succinic Anhydride Modified Early Indica Rice Starch
Authors: Song Xiaoyan , He Guoqing , Ruan Hui , Chen Qihe
Published: February 2006

Octenyl succinic anhydride (OSA) modified early indica rice starch was prepared in aqueous slurry systems and the major factors affecting the esterification were investigated systematically. The physicochemical properties of the products were determined by means of Fourier transform infrared (FT‐IR) spectroscopy, scanning electron microscopy (SEM), X‐ray diffraction and Rapid Visco Analyser (RVA). The results indicated that the suitable parameters for the preparation of OSA starch from early indica rice starch in aqueous slurry systems were as follows: concentration of starch slurry 35% (in proportion to water, w/w), reaction period 4 h, pH of reaction system 8.5, reaction temperature 35°C, amount of OSA 3% (in proportion to starch, w/w). The degree of substitution (DS) was 0 018 and the reaction efficiency (RE) was 78%. FT‐IR spectroscopy showed characteristic absorption of the ester carbonyl groups in the OSA starch at 1724 cm‐1. SEM and X‐ray diffraction revealed that OSA groups acted by first attacking the surface and some pores formed, but OSA modification caused no change in the crystalline pattern of rice starch up to DS 0.046. RVA results indicated that the starch derivatives gelatinized at shorter time to achieve higher viscosities with increased OSA modification.
Characterisation and Modelling of Specific Enthalpy and Heat Conductivity of Corn Grits under Consideration of Water Sorption Behaviour
Authors: Potente Helmut , Heim Hans‐Peter , Ernst Wolfgang , Föhrer Thorsten
Published: February 2006

Extrusion of starch is a common process not only in food industry, but also for technical applications. In this context, a special type of extruder with a very short plastication unit allows the processing of foamed products like loose‐fill based on non‐modified, starch‐containing raw materials. A crop product which has been defined as very suitable for this process is corn grit. In order to describe the process behaviour of an extrusion machine, the knowledge of the relevant material properties is indispensable.

This paper provides results from investigations focused on the determination of material data like specific enthalpy (SE) Δh and heat conductivity (HC) λ. Both characteristics increase with rising temperature and water content. Based on these experimental results, mathematical models have been formulated in order to calculate the specific enthalpy and heat conductivity in dependence on temperature and moisture content, which in turn depends on air temperature and relative humidity during the storing of the material before processing. Therefore, the water vapour sorption behaviour of this material was also investigated. The GAB model for the mathematical description of sorption behaviour of starch could also be applied to corn grits and integrated into the models for the calculation of Δh and λ

Specific enthalpy has been determined by DSC (differential scanning calorimetry), heat conductivity has been measured by using a device working with the “Line‐Source‐Method”.
Standards in behavioral teratology testing: Test variability and sensitivity
Authors: Butcher Richard E. , Wootten Virginia , Vorhees Charles V.
Published: February 2006

Regulatory guidelines have produced a need to develop behavioral screening techniques to accompany teratology and reproduction testing. In the repeated use of a provisional test battery, we have found that conclusions about the behavioral teratogenic potential of test compounds are most likely to be revealed using tests having intermediate levels of variability. The results obtained from examining animals exposed developmentally to brominated vegetable oil (BVO as 2.0, 1.0, 0.5, or 0.25 percent of the diet) and comparisons of the tests' co‐efficients of variation, offer an empirical example of this concept. Preweaning tests of locomotion and reflex development demonstrated numerous instances of developmental delay in the BVO‐treated subjects, but postweaning tests revealed few abnormalities. Behavioral testing revealed functional deficits from BVO administration at doses lower than those which have adverse effects on reproduction. Examination of the tests' variability by using coefficients of variation as a comparative index, disclosed that the postweaning test variability was almost twice that of the preweaning tests. Thus, the lack of effects of BVO on most of the postweaning tests should not be conclusively interpreted as indicative of recovery of function, because this pattern is equally likely to have resulted from the lower sensitivity of these tests. An acceptable standard for future behavioral teratology screening requires a close examination of test variability, as it appears to be an important element in the sensitivity and, hence, the interpretation of such procedures.
Alkylation of macromolecules for detecting mutagenic agents
Authors: Ehrenberg L. , Osterman‐Golkar Siv
Published: February 2006

At present, experiments with laboratory organisms and epidemiological studies are the major source of information about the genetic toxicology of environmental agents. Laboratory systems are limited in value by difficulties in the interpretation of negative results, in quantitation, and in extrapolation from experimental effects of chemicals to specific levels of activity in man. Epi‐demiologic methods measure effects in man but are weakened by long latency times, confounding environmental factors, imprecise endpoints, and high background levels, which reduce sensitivity. Several methodological improvements in genetic toxicity testing are needed, including increased resolving power, greater relevance of observations to effects in man, techniques for evaluating interactions of compounds in chemically complex systems, and improvements in quantitative risk assessment. Because most genetically toxic agents ultimately react as electrophilic agents with nucleophilic centers in cellular macro‐molecules, the quantitative analysis of the resulting products may be a useful approach to the evaluation of the risks posed by exposure to specific chemicals. The main nucleophilic centers in biological macromolecules are thiol and thioether sulfurs, nitrogens in amino groups and rings, and oxygen atoms. Using the laws of reaction kinetics of alkylation and the observed kinetics of induced mutagenic effects, it is possible to relate the formation of alkylated products in macromolecules to genetic toxicity. The alkylation of amino acids (eg, histidine and cysteine) in hemoglobin can be measured with sufficient sensitivity and accuracy to use it as a monitor of exposure to alkylating agents. By determining the degree of alkylation of a specific center, it is possible to calculate the internal dose of an agent and, because erythrocyte life‐spans are relatively uniform, the incremental daily exposure of an individual to an alkylating agent. Dosimetry can be equated with radiologic dose so that exposure can be expressed in rad‐equivalents and the effects of specific agents compared quantitatively to biologically well‐characterized doses of radiation.