bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation‐induced gas‐phase grafted polymerization as a method for producing macromolecular carries for active catalytic sites
Authors: Kritskaya D. A. , Ponomarev A. N. , Pomogailo A. D. , Dyachkovskii F. S.
Published: June 2010

To obtain polymer supports with different functional coverage, the kinetic peculiarities of radiation‐induced gas‐phase grafting of allyl (allyl alcohol, ally and diallyl amines) and vinyl (acryl and methacryl acids, their methyl ethers, methylvinylketone, 2‐ and 4‐vinylpyridine, acrylonitrile) monomers to polymer powder (polyethylene, polypropylene, polystyrene, and copolymer of ethylene with propylene) were studied. The degrees and radiation yields of grafting were measured and evidence of the grafting occurrence is given. The radiation yield of allyl monomers grafting to polyethylene was found to be 10–20 molecules/10 eV of absorbed energy and was found to keep constant on a change of the dose rate from 3 × 10−3to 6.5 Mrad/min. That testifies to the absence of second‐order chain termination and provides wide possibilities for effective use of various radiation sources. By grafting some monomers containing radioactive isotopes (14C,3H) and analyzing the grafted product after extraction, the ungrafted homopolymer content was shown to be less than 10%. The appearance of some additional absorption bands from fragments of the grafted monomers in the IR spectrum of the treated polymer was considered as evidence of grafting. Some polymer‐analogous reactions of the grafted polymer (reduction, saponification, hydrolysis, formation of Schiff bases) are given as illustrations of the validity of the method proposed for producing polyfunctional coverage of the macromolecular carries for active catalytic sites.
Comparative study of homogeneous and heterogenized cobalt systems by macromolecular supports in diene monomer polymerization
Authors: Golubeva N. D. , Pomogailo A. D. , Kuzaev A. I. , Ponomarev A. N. , Dyachkovskii F. S.
Published: June 2010

Isoprene and butadiene polymerization has been studied in the presence of homogeneous and heterogenized, polymer‐supported, “cobalt” catalytic systems. Donor‐acceptor or covalent heterogenization Co(II) compounds resulted in retardation of initiation and deactivation reactions in catalytic systems, in increasing molecular masses, and in an integral yield of polymers. It was concluded from analysis of growth‐rate constants, as well as from the structures of the polymers formed, that the active sites were the same in both types of catalysts. The heterogenized systems were postulated to inhibit yielding cobalt compounds in a reduced state.
Synthesis and catalytic properties of transition‐metal complexes immobilized on macromolecular supports in polymerization processes
Authors: Dyachkovskii F. S. , Pomogailo A. D.
Published: June 2010

Functional groups of polymers and copolymers have been considered as the reaction sites for immobilization of transition‐metal complexes. A new type of polymer support has been described, i.e., carbon‐chain polymers with a surface modification due to graft polymerization of monomers with functional groups. Methods have been proposed for investigating the composition and structure of immobilized catalysts. Immobilization of transition metals on polymer supports has been shown to increase their catalytic activity considerably as compared to homogeneous and pseudo‐homogeneous analogs in polymerization processes.
Use of the gel spheron in the study and analysis of polymerous nucleic acids and their components
Authors: Boháček J. , Blažíček G.
Published: June 2010

Rapid separation of polymerous deoxyribonucleic acid (DNA) from ethanol, acetone, or phenol was performed on Spheron P 1000 gel using a 210‐mm glass column of 4‐mm internal diam. for the purpose of determination of these current contaminations in DNA preparations. Complete separation of polymerous DNA from its components, adenine, guanine, cytosine, and thymine was achieved in the same column isocratically eluted with 2M (NH4)2SO4 in 20‐mM potassium phosphate buffer at pH 7. The procedure was found also to be useful for the evaluation of enzymatic degradation of the DNA. Products of deoxyribonuclease‐I digestion were clearly separated from those of untreated polymerous DNA within a 10‐min period. The mechanism responsible for the separation of polymerous DNA of various origin from its low‐molecular constitutents is based on the combined effects of molecular sieving and the specific sorption properties of the Spheron matrix used.
Adsorption chromatography of proteins on controlled‐pore glass
Authors: Mizutani Takaharu , Mizutani Akira
Published: June 2010

Adsorption chromatography on controlled‐pore glass was investigated by a pH‐gradient elution system in glycine buffer using standard proteins and rabbit serum. The pattern on the glass was similar to those on carboxymethylcellulose but there were some differences which might be derived from a cooperative aggregative force between glass and proteins.
Some aspects of organic polymer sorbents and their evaluation
Authors: Millar J. R.
Published: June 2010

The preparation and characterization of macroporous polymeric adsorbents are discussed. Problems arising in the characterization of macropore systems via surface‐area or pore‐size distribution and their relation to the adsorbent behavior of the product are described, and the significance of parameters such as “effective mean pore diameter” or the “inherent dipole moment” of functional groups are considered. An example of the development of a sorbent for a particular commercial process is given to illustrate the points discussed, and the application of novel carbonaceous materials to halocarbon removal is noted. Some pessimism is expressed concerning the practicability of determining the ideal sorbent for a given application by measurement of functionally related parameters.
Calibration of spreading function in GPC using statistical moments
Authors: Vozka S. , Kubín M. , Samay G.
Published: June 2010

A new method is proposed for determining the spreading factor h(v) in the Tung integral equation, based on moment analysis of original (uncorrected) and corrected, normal‐flow chromatograms of calibration standards. The reliability of the new procedure has been verified on model and computer‐generated chromatograms, and tested experimentally on standard GPC columns as well as on microcolumns used in high‐speed gel‐permeation chromatography; its accuracy has been compared with that of known methods. The proposed method is particularly suited to fast gel‐permeation chromatography where, by trading the speed of analysis for efficiency, one can dispense with the knowledge of the molecular‐weight averages of calibration standards. If a well‐characterized sample having a broad molecular‐weight distribution is available, the shape of the function h(v) can be determined with sufficient accuracy from a single chromatogram.
Gel chromatography of carbohydrates on polysaccharide gel
Authors: Eltekov Yu. A. , Strakhova N. M. , Kàlal J. , Peška J. , Štamberg J.
Published: June 2010

Liquid chromatographies of high and low‐molecular carbohydrates and polyethyleneglycols of different molecular masses were studied on porous microspherical cellulose. Dependence of the distribution coefficients of polymer molecules on molecular mass was determined. It was revealed that the distribution coefficient depends on the hydrodynamic diameters of the polymer molecules. The possibility of using macroporous polysaccharide gels in the liquid chromatography of polymers, in order to study carbohydrates and other water soluble polymer, was discussed.
Phase separation phenomena in solutions of cellulose acetate. I. Differential scanning calorimetry of cellulose acetate in mixtures of dioxane and water
Authors: Altena F. W. , Smolders C. A.
Published: June 2010

The nature and kinetics of phase separation processes of solutions of cellulose acetate (degree of substitution, 2.5) in mixtures of dioxane and water are studied by differential scanning calorimetry (DSC). The thermograms on heating show small endothermic effects, detectable only after prolonged aging below the phase separation temperature. Experiments in two regions of the ternary diagram are of interest for the description of the formation mechanism of asymmetric membranes viz., (1) at high polymer and high concentrations and low concentrations of nonsolvent (gelation); (2) at lower polymer concentrations of nonsolvent (liquid–liquid separation followed by gelation). Endothermic effects after prolonged aging are found at high polymer concentrations (≥40%). These results demonstrate that gelation is very slow in these systems. At lower concentrations of polymer and high concentrations of nonsolvent (up to 40%) a more rapid type of phase separation can be observed visually on cooling. The temperature where turbidity sets in (the cloud point) is independent of the rate of cooling. In DSC experiments no exothermic effect is found on cooling. Again, after aging an endothermic effect is present. The endothermic peak, which is situated below the cloud point, is probably a result of melting of the gelled concentrated phase.
Thermal properties of intact nucleoproteides
Authors: Monaselidze J. R. , Chanchalashvili Z. I. , Mgeladze G. N. , Madjagaladze G. V. , Chitadze G. Sh.
Published: June 2010

It is established that the process of chromatin melting in tissues proceeds in one stage with the following transition parameters: T = 82°C, Δ T = 7°C, and Q = 24 cal/g DNA. The difference between the heats of melting for chromatin and DNA is 12 cal/g and corresponds to the melting of the secondary and tertiary structure of chromatin.
Thermodynamics of protonation of polymeric bases whose repeating units behave independently
Authors: Barbucci Rolando , Barone Vincenzo , Ferruti Paolo , Oliva Leone
Published: June 2010

The protonation of some poly(amido amine)s has been studied in aqueous solution by potentiometric, calorimetric, and 13C‐NMR methods. Only “apparent” constants were usually found in polymeric acids and bases; on the other hand, “sharp” basicity constants could be determined for the poly(amido amine)s studied. The log K values determined from 13C‐NMR shifts versus pH agree well with those determined by potentiometric titrations. Also, the protonation enthalpies do not depend on the dissociation degree of polymeric bases, and this is a further proof of the peculiarity of this class of polymers. The trends of ΔH's and the conformations of polymers in solution are analyzed on the basis of theoretical computations.
Mixing enthalpies of polymers with mesomorphic properties and mesogenic plasticizers
Authors: Cser F. , Nyitrai K. , Hardy G. , Menczel J. , Varga J.
Published: June 2010

Mixtures of polymers of mesomorphic properties with mesogenic plasticizers were investigated by differential scanning calorimetry (DSC). The nature of the mesomorphic structure of the polymers could be identified by studying the concentration dependence of such thermal processes as glass transition, mutual solution of the phases and formation of eutectic melts. Mixtures of polymers with a supposed nematic structure such as poly(phenyl‐p‐acryloyloxy‐benzoate) (pPAB), poly(p‐butoxy‐phenyl‐p‐acryloyloxy‐benzoate) (pBPAB), poly(p‐methoxy‐phenyl‐p‐methacryloyloxy‐ethoxy‐benzoate) (pMPMEB), and one copolymer of p‐methyl‐p'‐acryloyloxy‐azoxy‐benzene (MAAB) and cholesteryl‐vinyl‐succinate (CVS) and of nematogenic materials as terephthal‐bis‐butyl‐aniline (TBBA), p‐butoxy‐phenyl‐p‐propionyloxy‐benzoate (BPPB) and the monomers of the copolymer were investigated. None of the systems was found fully miscible with nematic structure. The enthalpies of melting at the clearing points were found proportional to the polymer content of the mixtures. The mixing enthalpies in the liquid state are too small to be measured by DSC. The mixing enthalpies of the solid components resulting in solid plasticized polymer are found proportional to the melting enthalpies of the plasticizers and to their saturation concentration in the polymer. The anisotropy of the bulk polymer originated from the anisometric geometrical shape of the macromolecules themselves, which is in good agreement with the structural concept introduced earlier.
The thermal properties of polypropylene
Authors: Grebowicz Janusz , Lau S.‐F. , Wunderlich Bernhard
Published: June 2010

The thermodynamic properties of isotactic polypropylene in the fully crystalline, glassy, and molten state are established from 0 to 500 K based on data bank heat capacities and the vibrational frequency spectrum. The seven skeletal vibrations are described by θ3 and θ1 of 91 and 714 K for crystalline polypropylene. For the calculation of Cp − Cv, a Lindemann A0 value of 1.5 × 10−3 K mol/J was found. Calculated and experimental heat capacity data show agreement within an average error of −0.3 ± 1.6%. Glassy polypropylene was similarly treated up to the glass transition temperature at 260 K (θ3 = 78 K, θ1 = 633 K, average heat capacity error −0.6 ± 2.8%). The residual 0 K entropy of glassy polypropylene is 1.9 J/K mol. Partially crystalline polypropylene is shown through high‐sensitivity DSC measurements to have a glass transition range from 260 to 380 K. Similarly, high‐sensitivity DSC has been used to characterize the condis phase of polypropylene (conformationally disordered polypropylene) which was prior called “smectic mesophase” or “paracrystalline.” Its heat of transformation to the stable crystal phase is 600 J/mol.
Some rheological properties of solutions and blends of hydrogenated polybutadiene
Authors: Graessley W. W. , Raju V. R.
Published: June 2010

This article describes work with model polymers to explore the effects of long branches on polyethylene melt rheology. Dynamic moduli were measured at two or more temperatures on melts, blends, and solutions of linear (L) and star (B) hydrogenated polybutadiene (HPB). Enhancement factor Γ and temperature coefficient (flow activation energy Ea) were determined from viscosity data and correlated with arm molecular weight Mb and volume fraction of the star component Φ. As in other species, Γ for a given branch point functionality is roughly an exponential function of Φ11/6Mb in entangled melts and solutions. In contrast with other species, however, (Ea)B and (Ea)L are different; (Ea)B – (Ea)L is directly proportional to ΦMb, and the degree of thermorheological complexity varies primarily with (Ea)B – (Ea)L. In blends with linear HPB of comparable viscosity, Γ for the star component remains essentially constant, and (Ea)B – (Ea)L is directly proportional to the volume fraction of the star component.
Conformational properties of perfluoroalkane chains. VI. Intrinsic viscosity and unperturbed dimensions of poly(decamethylene perfluorosebacate)
Authors: Matsuo Keizo , Stockmayer W. H. , Needham G. F.
Published: June 2010

Light‐scattering and viscosity measurements are reported for fractions of poly(decamethylene perfluorosebacate). Intrinsic viscosity (dL/g) relationships at 25°C are [η] = 1.55 × 10−4Mv0.70 in chloroform and (η) = 8.8 × 10−4Mv0.50 in s‐tetrachloroethane. From these data the characteristic ratio is found to be Cθ = 6.3 ± 0.5, indicating that the perfluoroalkane chain is not much more extended than an alkane chain. The solid semicrystalline polymer melts at 45°C, and its x‐ray powder pattern suggests a structure different from that of poly(decamethylene sebacate).
Miscible blends of a vinylidene chloride/vinyl chloride copolymer with polymethacrylates
Authors: Woo E. M. , Barlow J. W. , Paul D. R.
Published: June 2010

A copolymer of vinylidene chloride and vinyl chloride containing 13.5% of the latter has been found to form completely miscible blends with atactic and isotactic poly(methyl methacrylate). poly(ethyl methacrylate), poly(n‐propyl methacrylate), and poly(cyclohexyl methacrylate). All but the latter of these blends were shown to exhibit lower critical solution temperature behavior at temperatures below that at which the copolymer rapidly degrades. The copolymer was found to be only partially miscible with poly(isopropyl methacrylate), while no detectable level of miscibility was observed with poly(methyl acrylate), poly(ethyl acrylate), poly(vinyl acetate), poly(vinyl methyl ether), or poly(vinyl methyl ketone). Information about interactions between components in the miscible blends was estimated from melting point data and is discussed.
Reaction kinetics of polymeric reagents
Authors: Morawetz H.
Published: June 2010

Kinetic studies of reactions in systems containing polymers have led to the following observations: (1) In dilute solution the thermal and the photochemical isomerization of azobenzene residues is not impeded by their incorporation into a polymer backbone. In the glassy state, the kinetics of the isomerization of azobenzene residues in polymer side chains or backbones reflect the distribution of free volume and volume relaxation. (2) Reactions of polymers with low molecular weight reagents may be affected by neighboring group effects and by the contribution of the polymer backbone to the polarity of its microenvironment. (3) Attack of an enzyme on a polymer side chain depends sharply on the spacing of the susceptible bond from the chain backbone. (4) The expected “kinetic excluded volume effect” in reactions between two flexible chain molecules was not observed. (5) Reactions involving groups attached to a swollen crosslinked gel may reflect spatial variations of the local polarity. (6) Attack of water‐soluble reagents on latex particles may be restricted to the surface of the particle. (7) The presence of a polyion exerts various effects on reactions involving two small ionic species.
Reactive functional latex polymers
Authors: Upson D. A.
Published: June 2010

Examples of functional monomers and latex polymers are described. Use of functional monomers allows great versatility in the design of latex polymers with specialized properties. Included are examples of electrophilic, nucleophilic, crosslinkable, hydrolyzable, and metalion‐chelating monomers.
New block copolymers and networks from telechelic prepolymers
Authors: Kennedy Joseph P.
Published: June 2010

The synthesis and characterization of isobutylene/styrene tri‐ and H‐block polymers, and the copolymerization of α,ω‐styryl polyisobutylenes with N‐vinyl pyrrolidone will be presented.
Syndiotactic polypropylene
Authors: Elias Hans‐G. , Ogawa Toshio , Kim Young‐Ha
Published: June 2010

Propylene is the only monomer which can be polymerized both isospecifically and syndiospecifically with the same family of catalysts, i.e., organometallic compounds of the Ziegler–Natta type. Whereas isotactic poly(propylene) can be manufactured by reasonable polymerization conditions to highly valued thermoplastics, the corresponding syndiotactic polypropylene has remained a laboratory product. However, theoretical considerations show that syndiotactic polypropylene may possess some ultimate properties which surpass those of isotactic polypropylene. Propylene was thus polymerized with various catalyst systems and the resulting polymers characterized by carbon‐13 nuclear magnetic resonance, infrared spectroscopy, X‐ray diffraction, gel permeation chromatography, differential scanning calorimetry, and stress/strain measurements [1,2]. Several polymers were fractionated. The combined evidence points toward stereoblocks in syndiotactic polypropylenes [1]. The highest syndiotacticities achieved are, however, still too low to permit the ultradrawing to highly oriented polymers, which would allow approaching the ultimate properties. This result is probably due to a stereostatistic peculiar to the catalyst system, i.e., a symmetric Markov statistic of the first order [3]. This statistic predicts the experimentally found linear dependence of triad fractions on diad fractions [4], a characteristic restricted diad range, and an unusual dependence of the heterotacticity index on the diad contents. The same formalism also describes the features of the so‐called heterotactic polymerizations.
Brittle fracture in PVC pipe material
Authors: McGarry Frederick J. , Mandell John F. , Hsueh‐Lee Lidia
Published: June 2010

Methods to measure the plane strain fracture toughness (K1c) of PVC pipe material, valid according to linear elastic fracture mechanics (LEFM), have been developed. As in metals practice, the crack tip plastic zone must be small compared to initial crack length, section thickness, and other specimen dimensions to achieve validity. Other conditions of test rate and temperature also must be fulfilled. K1c values vary from 2.8 to 4.0 MN m−3/2. Quantitative micromechanical analyses of the plastic flow regions on the fracture surfaces account for only a fraction of the measured toughness. Other deformation mechanisms (crazing) below but near the surfaces have been observed; apparently they absorb the balance of the work required to drive the stable crack. Under catastrophic, rapid crack propagation, only a single craze exists ahead of the crack tip; the multiple crazes disappear. Thus the dynamic fracture toughness may be several factors less than the static or stable value.
Diffusion in polymer‐solvent systems
Authors: Duda J. Larry , Vrentas James S.
Published: June 2010

Recent advances in the area of molecular diffusion in polymer‐solvent systems will be reviewed. Alfrey's classification scheme for the diffusion of solvent molecules in polymers will be used as a starting point. It will be shown that the various regions on Alfrey's diagram are distinguished by the ratio of two characteristic times, a characteristic relaxation time for the polymer‐solvent system and a characteristic diffusion time. Fickian diffusion is realized when this characteristic ratio is a small number, and anomalous behavior occurs when these two characteristic times are the same order of magnitude. Alfrey's “null” region corresponds to those conditions where this dimensionless ratio is much greater than one. The different manifestations of anomalous diffusion with polymer‐solvent systems will be discussed, including case II transport as defined by Alfrey, Gurnee, and Lloyd. Finally, diffusion in polymer‐solvent systems above the glass transition temperature where classical diffusion theory is applicable will be considered. Emphasis will be placed on the demonstration of the ability of theoretical methods based on free volume concepts to predict the concentration and temperature dependencies of diffusion coefficients. The extension of this free volume theory to describe diffusion in glassy polymers will also be demonstrated. Experimental results for several polymer‐solvent systems which exhibit different types of transport behavior will be used to illustrate the correlative and predictive capabilities of these recently developed theories.
Some contributions of turner alfrey to fabrication of polymers
Authors: Schrenk W. J.
Published: June 2010

Enhancement of polymer properties by controlling supramolecular structure during fabrication was of major interest to Turner Alfrey. Supramolecular structure, i.e., the geometric arrangement of macromolecules in a specimen, is established during mechanical processing and can have a profound effect on properties. Several examples of Alfrey's contributions to fabrication of polymers are reviewed which demonstrate the Alfrey method of analyzing complicated fabrication processes.
Pump‐assisted plasticating extrusion*
Authors: McKelvey James M.
Published: June 2010

Within the past several years considerable interest has developed in the practice of retrofitting of plasticating extruders with gear pumps. The primary motivation for this is to reduce surges and fluctuations in the extrusion rate, thereby improving product quality and reducing waste. It is shown that the effectiveness of a gear pump for this purpose is directly related to its volumetric efficiency. The volumetric efficiency depends upon the pump dimensions, the flow behavior of the polymer, and the operating variables of temperature, pressure, and pump speed. Experimental data on a variety of thermoplastic materials has been obtained using a pump with gear wheels of 3.6 cm diameter. These data have been correlated with an empirical equation. Some tentative conclusions are drawn concerning the sizing of gear pumps for specific applications.
Gelation by additive polymerization in two dimensions
Authors: Rushton Andrew F. , Family Fereydoon , Herrmann Hans J.
Published: June 2010

Kinetics of gelation by additive polymerization on a two‐dimensional lattice were investigated with a Monte Carlo simulation. We have determined the critical component γ and the ratio R of the critical amplitudes of the weight‐average degree of polymerization (“susceptibility”) to be γ = 3.8 ± 0.5 and R = 140 ± 45. These results show that this model is neither in the universality class of standard percolation (γ ± 43/18 ± 2.38; R = 219 ± 25) nor the Flory‐Stockmayer model (γ = 1, R = 1).
Kinetics of aggregation and gelation
Authors: Stanley H. Eugene , Family Fereydoon , Gould Harvey
Published: June 2010

We define six kinetic growth models that have witnessed an explosion of recent activity:

Cancer Growth (Eden)

Colloid Growth (Langer‐Müller‐Krumbhaar; Witten‐Sander)

Breakdown (Sawada et al.)

Crystallization (Rikvold)

Invasion Percolation (Schlumberger group)

Addition Polymerization (Manneville‐de Seze; Herrmann et al.)

We also describe briefly some of the approaches used to study these models, with emphasis on the re normalization group approach being developed by us.
Polymer reptation in semidilute solution
Authors: Schaefer D. W.
Published: June 2010

The self‐diffusion constant and solution viscosity are calculated for polymers in semidilute solution using the reptation concept. A space‐filling constraint (rather than binary contacts) is used to construct the tube in the reptation model. In good solvents, scaling predictions are recovered, but in marginal systems unexpected effective power‐law exponents are predicted for the concentration dependence of the self‐diffusion constant, relative viscosity, and reptation time.
Simulation of entangled polymer chains
Authors: Deutsch J. M.
Published: June 2010

The dynamics of polymers are investigated in the regime of high molecular weight and high concentration using Monte Carlo dynamics. The lattice model used is described, and the idealizations used in this and other models are discussed. The results are presented and compared with the results of previous simulations.
Multifunktionale Gebäudehülle und Raum im Raum – Die Cité du Design in St. Etienne/Frankreich
Authors: Sobek Werner , Winterstetter Thomas
Published: June 2010

Die nach den Plänen des deutsch‐französischen Architekten Finn Geipel errichtete Cité du Design in Saint‐Etienne soll sich zum führenden Zentrum für Design entwickeln und als solches wesentliche Impulse zum Strukturwandel in dieser zentralfranzösischen Region geben. Die Cité du Design bietet Raum für verschiedene Institutionen, Initiativen und Unternehmen aus dem Bereich des Design sowie der Informationstechnologie. Das Bauvorhaben besteht aus der sogenannten Platine, einem Aussichtsturm und den umgebauten Gebäuden einer ehemaligen Waffenmanufaktur (Bild 1). Die Platine spielt die zentrale Rolle im Gesamtprojekt: sie bietet wichtige Funktionen wie Ausstellungsräume, Säle für Veranstaltungen und eine Bibliothek. Der Aussichtsturm hatte als erstes fertig gestelltes Gebäude eine wesentliche kommunikationsstrategische Aufgabe zu erfüllen. Der vorliegende Aufsatz widmet sich den neu errichteten Gebäuden, d. h. der Platine und dem Aussichtsturm, die sich durch ihr filigran gestaltetes Stahltragwerk auszeichnen.

Multifunctional building envelope and space‐and‐space – The Cité du Design in St. Etienne/France. The Cité du Design in Saint‐Etienne, built according to the German‐French architect Finn Geipel's designs, is planned to be developed as a leading centre of design and to drive further the structural change in this central French region. The Cité du Design offers space for various institutions, initiatives and companies from the field of design as well as information technology. The project consists of the so‐called Platine, an observation tower and renovated buildings of a former weapon factory. The Platine is the main part of the project and offers important functions such as showrooms, event halls, and a library. The observation tower, the first completed building, had to fulfil an essential task in communication strategy. The following essay presents the newly set up buildings, i. e. the Platine and the observation tower, both of which are characterised by their filigree steel structure design.
Zuschriften zu: Schrade, Chr.: Ermüdungsprobleme prismatischer, trogförmiger Eisenbahnbrücken mit dicken Blechen und deren Bewältigung.
Authors: Gläßer Katrin
Published: June 2010

[Stahlbau 79 (2010), H. 2, S. 136–143 ]
Radiologic and Pathological Correlation of Staging of Rectal Cancer with 3 Tesla Magnetic Resonance Imaging
Authors: Chatterjee Parangama , Eapen Anu , Perakath Benjamin , Singh Ashish
Published: June 2010

Purpose

To assess the sensitivity and specificity of 3 Tesla magnetic resonance imaging (MRI) in the prediction of extramural spread and metastatic adenopathy in rectal carcinoma.

Materials and Methods

This was a prospective cohort study that included forty consecutive patients with rectal carcinoma from the Department of Colorectal Surgery. Three Tesla (3T) MRI was performed on these patients after a 4-hour fast and cleansing water enema. TI-weighted and T2-weighted images were obtained with high-resolution images T2-weighted sequences through the pelvis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 3T MRI for prediction of metastatic adenopathy and extramural spread were calculated. The TNM staging based on MRI was compared with histopathology of the resected specimen (taken as the criterion standard).

Results

In our study, sensitivity, specificity, PPV, and NPV of 3T MRI for prediction of metastatic adenopathy were 100%, 78.3%, 77.3%, and 100%, respectively. Sensitivity, specificity, PPV, and NPV of 3T MRI for prediction of extramural tumour spread were 100% and 20%, 89.7% and 100%, respectively (ie, prediction of stages T3 and above).

Conclusion

MRI allows accurate measurement of the depth of extramural tumour spread. In the assessment of metastatic adenopathy, however, MRI has a low specificity. This study shows that MRI is unlikely to miss any significant parameter in staging of rectal carcinoma. However, it has a tendency to overstage extramural spread of tumour.
Home‐Based Life‐Saving Skills in Liberia: Acquisition and Retention of Skills and Knowledge
Authors: Lori Jody R. , Majszak Christina M. , Martyn Kristy K.
Published: June 2010

Introduction: In 2006, Home‐Based Life‐Saving Skills was introduced in three Liberian counties, in partnership with Africare‐Liberia and the Liberian Ministry of Health and with funding by the United States Agency for International Development.

Methods: Traditional midwives and trained traditional midwives (N = 412) underwent pre‐ and immediate posttesting on four topics. Three hundred eighty‐nine (94%) of the original participants also completed 1‐year follow‐up posttesting.

Results: Mean scores significantly improved between pre‐ and immediate posttests and knowledge improvement was stable at 1 year. Correct responses on individual steps for each of four topics significantly increased over the course of training. The data demonstrate a major change in the knowledge base of the traditional and trained traditional midwives acting as village guides.

Discussion: Home‐Based Life‐Saving Skills is a viable means by which to improve community knowledge and decrease maternal and neonatal morbidity and mortality.
The Sexual Health of Women After Gynecologic Malignancy
Authors: Audette Corinne , Waterman Jeannine
Published: June 2010

Each year in the United States, approximately 80,000 women are diagnosed with gynecologic cancers. Cancer in the female reproductive organs affects sexual functioning in an estimated 50% of women with these cancers. Sexuality issues may persist for more than 10 years after diagnosis, making awareness of these issues an important factor in efforts to improve the quality of life for these women. This article reviews how sexuality is affected and provides recommendations for effective communication, assessment, and management strategies related to sexual dysfunction in gynecologic cancer survivors.
Plankton of the central Great Barrier Reef: abundance, production and trophodynamic roles
Authors: Sorokin Yu.I. , Sorokin P.Yu.
Published: June 2010

The abundance, composition and metabolic activity of plankton were assessed in the Tribulation zone of the central Great Barrier Reef (16°–17°S). Wet phytoplankton biomass ranged in shallow reef waters from 30 to 70 mg m−3, and from 60 to 270 mg m−3in the deep lagoon and in the estuarine areas which are dominated by pico- and nano-algae. Wet bacterioplankton biomass varied from 70 to 290 mg m−3. Wet meroplankton biomass was less than 10 mg m−3. Wet daytime mesozooplankton biomass ranged from 100 to 300 mg m−3in the deep lagoon. In the estuarine area, it reached 400 to 1300 mg m−3and in the shallow inner lagoon of the Low Isles ring reef it varied from 10 to 30 mg m−3. Zooplankton density increased at night and was 3 to 5 fold greater in the deep lagoon, for about 2 orders of magnitude greater over the reef shallows and up to 3 orders of magnitude greater in mangrove habitats, due to the emergence of demersal components from the benthos. The biomass of zooplankton hidden in the benthic substrates during the day reached 10 to 40 g m−2. Pelagic primary production in the deep lagoon varied between 0.2 and 0.5 g C m−2 d−1. A calculation of the energy balance suggests that the basic energy source for heterotrophic plankton production in the deep lagoon is the organic matter exported from surrounding reef benthic communities and from mangroves. The trophic status of coral reef pelagic ecosystem might range from mesotrophic to eutrophic.
Diversity of Indo-AustralianPlakortis(Demospongiae: Plakinidae), with description of four new species
Authors: Muricy Guilherme
Published: June 2010

A collection of 32 specimens of the genusPlakortis(Demospongiae: Plakinidae) from Australia and the Indo-Pacific is here examined. Six species are described, four of which are new to science.Plakortis litahas microrhabds, an irregular tangential ectosomal reticulation, a confused choanosomal skeleton and irregular diods and triods.Plakortis quasiamphiasterhas quasiamphiasters (spined diods and triods), spheres and a skeleton with a distinct subectosomal region.Plakortis communissp. nov. has diods and a tangential ectosomal reticulation with circular meshes; triods and spheres may be present or absent.Plakortis bergquistaesp. nov. has diods in two size-classes, the larger one up to 330–356 µm long, and large triods (actines up to 75–121 µm long).Plakortis fromontaesp. nov. has large diods (up to 220 µm long), rare triods and a double ectosomal reticulation.Plakortis hooperisp. nov. has diods, triods, microrhabds and spheres, with a confused ectosomal skeleton, a thinly encrusting shape and cream colour. Detailed descriptions of external morphology, skeletal arrangement of the ectosome and spicules in SEM are essential for the taxonomy ofPlakortis. The number of valid species in the genus is raised from 15 to 19. A key to Indo-Australian species ofPlakortisis given.
Physical Integrity Rights and Terrorism
Authors: Piazza James A. , Walsh James Igoe
Published: June 2010

Can states afford to protect human rights when facing a terrorist threat? Contemporary academic literature suggests that the answer to this question is no, concluding that states that afford their citizens basic political rights and civil liberties leave themselves more exposed to terrorist attacks (Piazza 2008; Wade and Reiter 2007; Pape 2003; Eubank and Weinberg 1994). American policymakers seem to agree. Both the Bush and Obama administrations regard the curtailment of physical integrity rights as a necessary element of effective counterterrorism policy. The Bush administration responded to the terrorist attacks of September 11, 2001, with policies permitting indefinite detention, extraordinary rendition, use of physically abusive interrogation practices, and increased and largely unchecked surveillance and wiretapping of suspected terrorists. Although it banned abusive interrogation and announced plans to close the detention facility at Guantanamo Bay, the Obama administration has maintained the practice of wiretapping, reserved the option of rendition, and dramatically increased unmanned drone attacks against suspected terrorists in Pakistan, which often results in civilian casualties. Both presidents have claimed that these policies are necessary to keep Americans safe from terrorism (Hosenball 2009; “Bush Defends Policy on Terror Detainees” 2005).
IN MEDIAS RACE (AND CLASS)
Authors: Jackson John L.
Published: June 2010

“Race is the modality in which class is lived” (Hall et al., 1978, p. 394). That's how Stuart Hall evocatively put it, emphasizing the extent to which class relations can actually and substantively “function as race relations” for working class Black Brits (and others). He was arguing, amongst other things, against the neatly reified distinctions scholars traditionally policed between class-based analyses and racial ones.
STILL WALKING THE TIGHTROPE
Authors: Bobo Lawrence D. , Dawson Michael C.
Published: June 2010

This issue of the Du Bois Review: Social Science Research on Race is dedicated to the living memory and many contributions of distinguished historian John Hope Franklin. Writing in his autobiography Mirror to America, Franklin said that:
Role of Salt-Induced Kinase 1 in Androgen Neuroprotection against Cerebral Ischemia
Authors: Cheng Jian , Uchida Masayoshi , Zhang Wenri , Grafe Marjorie R , Herson Paco S , Hurn Patricia D
Published: June 2010

Androgens within physiological ranges protect castrated male mice from cerebral ischemic injury. Yet, underlying mechanisms are unclear. Here, we report that, after middle cerebral artery occlusion (MCAO), salt-induced kinase 1 (SIK1) was induced by a potent androgen—dihydrotestosterone (DHT) at protective doses. To investigate whether SIK1 contributes to DHT neuroprotection after cerebral ischemia, we constructed lentivirus-expressing small interference RNA (siRNA) against SIK1. The SIK1 knockdown by siRNA exacerbated oxygen–glucose deprivation (OGD)-induced cell death in primary cortical neurons, suggesting that SIK1 is an endogenous neuroprotective gene against cerebral ischemia. Furthermore, lentivirus-mediated SIK1 knockdown increased both cortical and striatal infarct sizes in castrated mice treated with a protective dose of DHT. Earlier studies show that SIK1 inhibits histone deacetylase (HDAC) activities by acting as a class IIa HDAC kinase. We observed that SIK1 knockdown decreased histone H3 acetylation in primary neurons. The SIK1 siRNA also exacerbated OGD-induced neuronal death in the presence of trichostatin A (TSA), an HDAC inhibitor, and decreased histone H3 acetylation at 4 hours reoxygenation in TSA-treated neurons. Finally, we showed that DHT at protective doses prevented ischemia-induced histone deacetylation after MCAO. Our finding suggests that SIK1 contributes to neuroprotection by androgens within physiological ranges by inhibiting histone deacetylation.
IUPAC-NIST Solubility Data Series. 88. Esters with Water—Revised and Updated. Part 3. C7 to C9 Esters
Authors: Mączyński Andrzej , Wiśniewska-Gocłowska Barbara
Published: June 2010

The mutual solubilities and related liquid-liquid equilibria of 60 binary systems of C7 to C9 esters with water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2007 are compiled. For 26 systems, sufficient data are available to allow critical evaluation. All data are expressed as mass fraction and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a method based on the evaluation of all experimental data for a given series of esters was used.
Temperature-dependent Raman scattering of KTa1−xNbxO3 thin films
Authors: Bartasyte A. , Kreisel J. , Peng W. , Guilloux-Viry M.
Published: June 2010

We report a Raman scattering investigation of KTa1−xNbxO3 (x=0.35,0.5) thin films deposited on MgO and LaAlO3 as a function of temperature. The observed phase sequence in the range from 90 to 720 K is similar to the structural phase transitions of the end-member material KNbO3. Although similar in the phase sequence, the actual temperatures observed for phase transition temperatures are significantly different from those observed in the literature for bulk samples. Namely, the tetragonal (ferroelectric) to cubic (paraelectric) phase transition is up to 50 K higher in the films when compared to bulk samples. This enhanced ferroelectricity is attributed to biaxial strain in the investigated thin films.
Nanoscale modulation of electronic states across unit cell steps on the surface of an epitaxial colossal magnetoresistance manganite film
Authors: Rana Abhimanyu , Bogle Kashinath , Game Onkar , Patil Shankar , Valanoor Nagarajan , Ogale Satishchandra
Published: June 2010

The nature of electronic states near the edge of unit cell steps on the surface of epitaxial La0.7Sr0.3MnO3 (LSMO) thin films grown by real-time reflection high energy electron diffraction monitored pulsed laser deposition is examined by scanning tunneling microscopy and scanning tunneling spectroscopy techniques. It is observed that the electronic states are strongly modulated near the step edge with considerably high gap at the edge and low gap on the terrace. This modulation weakens at low temperature. The temperature evolution of the density of states and the nature of gap in deep metallic state of LSMO are also discussed.
Nanostructured interfaces in polymer solar cells
Authors: Wiedemann W. , Sims L. , Abdellah A. , Exner A. , Meier R. , Musselman K. P. , MacManus-Driscoll J. L. , Müller-Buschbaum P. , Scarpa G. , Lugli P. , Schmidt-Mende L.
Published: June 2010

The morphology in organic photovoltaics plays a key role in determining the device efficiency. We propose a method to fabricate bilayer devices with controlled nanostructured interfaces by combining nanoimprinting and lamination techniques. This technique allows us to achieve a network structure of donor-acceptor material with a ∼80 nm periodicity and ∼40 nm width. These structures have an abrupt interface between the donor and acceptor materials and show an increased effective interfacial area and photovoltaic performance compared to bilayer solar cells. In contrast to blend films, they will allow an in depth analysis of the influence of morphology on interfacial physical processes.
Extranuclear estrogen receptor-α stimulates NeuroD1 binding to the insulin promoter and favors insulin synthesis
Authors: Wong Winifred P. S. , Tiano Joseph P. , Liu Suhuan , Hewitt Sylvia C. , Le May Cedric , Dalle Stéphane , Katzenellenbogen John A. , Katzenellenbogen Benita S. , Korach Kenneth S. , Mauvais-Jarvis Franck
Published: June 2010

Estrogen receptors (ERs) protect pancreatic islet survival in mice through rapid extranuclear actions. ERα also enhances insulin synthesis in cultured islets. Whether ERα stimulates insulin synthesis in vivo and, if so, through which mechanism(s) remain largely unknown. To address these issues, we generated a pancreas-specific ERα knockout mouse (PERαKO
−/−
) using the Cre-loxP strategy and used a combination of genetic and pharmacologic tools in cultured islets and β cells. Whereas 17β-estradiol (E2) treatment up-regulates pancreatic insulin gene and protein content in control ERαlox/lox mice, these E2 effects are abolished in PERαKO
−/−
mice. We find that E2-activated ERα increases insulin synthesis by enhancing glucose stimulation of the insulin promoter activity. Using a knock-in mouse with a mutated ERα eliminating binding to the estrogen response elements (EREs), we show that E2 stimulation of insulin synthesis is independent of the ERE. We find that the extranuclear ERα interacts with the tyrosine kinase Src, which activates extracellular signal-regulated kinases
1/2
, to increase nuclear localization and binding to the insulin promoter of the transcription factor NeuroD1. This study supports the importance of ERα in β cells as a regulator of insulin synthesis in vivo.
A conserved pattern of brain scaling from sharks to primates
Authors: Yopak Kara E. , Lisney Thomas J. , Darlington Richard B. , Collin Shaun P. , Montgomery John C. , Finlay Barbara L.
Published: June 2010

Several patterns of brain allometry previously observed in mammals have been found to hold for sharks and related taxa (chondrichthyans) as well. In each clade, the relative size of brain parts, with the notable exception of the olfactory bulbs, is highly predictable from the total brain size. Compared with total brain mass, each part scales with a characteristic slope, which is highest for the telencephalon and cerebellum. In addition, cerebellar foliation reflects both absolute and relative cerebellar size, in a manner analogous to mammalian cortical gyrification. This conserved pattern of brain scaling suggests that the fundamental brain plan that evolved in early vertebrates permits appropriate scaling in response to a range of factors, including phylogeny and ecology, where neural mass may be added and subtracted without compromising basic function.
Human ESCRT-III and VPS4 proteins are required for centrosome and spindle maintenance
Authors: Morita Eiji , Colf Leremy A. , Karren Mary Anne , Sandrin Virginie , Rodesch Christopher K. , Sundquist Wesley I.
Published: June 2010

The ESCRT pathway helps mediate the final abscission step of cytokinesis in mammals and archaea. In mammals, two early acting proteins of the ESCRT pathway, ALIX and TSG101, are recruited to the midbody through direct interactions with the phosphoprotein CEP55. CEP55 resides at the centrosome through most of the cell cycle but then migrates to the midbody at the start of cytokinesis, suggesting that the ESCRT pathway may also have centrosomal links. Here, we have systematically analyzed the requirements for late-acting mammalian ESCRT-III and VPS4 proteins at different stages of mitosis and cell division. We found that depletion of VPS4A, VPS4B, or any of the 11 different human ESCRT-III (CHMP) proteins inhibited abscission. Remarkably, depletion of individual ESCRT-III and VPS4 proteins also altered centrosome and spindle pole numbers, producing multipolar spindles (most ESCRT-III/VPS4 proteins) or monopolar spindles (CHMP2A or CHMP5) and causing defects in chromosome segregation and nuclear morphology. VPS4 proteins concentrated at spindle poles during mitosis and then at midbodies during cytokinesis, implying that these proteins function directly at both sites. We conclude that ESCRT-III/VPS4 proteins function at centrosomes to help regulate their maintenance or proliferation and then at midbodies during abscission, thereby helping ensure the ordered progression through the different stages of cell division.
Aperture obstruction influences birefringence evaluation of a Nd : YAG laser system with tandem-set rods
Authors: Wang You , Kan Hirofumi , Ogawa Takayo , Wada Satoshi
Published: June 2010

In this study, we derive a theoretical and experimental expression for evaluating the thermally induced birefringence (TIB) in a Nd : YAG laser system with double rods in tandem. The analytical solution determines the optimum oscillator geometry corresponding to the minimum depolarization loss while the so-called aperture obstruction is considered in the calculation model. It can be seen that the experimental results closely follow the theoretical evaluation for both the depolarized degree and the birefringent distribution of a probe beam. We also find that the traditional evaluation method, which neglects the thermally induced lens effect and aperture truncation during the optical design, leads to an obvious deviation in determining the optimum arrangement of a laser system for compensation of birefringence. The method presented in this paper is thought to be useful in analysing any high-powered oscillators or amplifiers with high pulse energy.