bluuebunny/crossref_metadata_2025 huggingface dataset:
Stretchable, Large‐area Organic Electronics
Authors: Sekitani Tsuyoshi , Someya Takao
Published: March 2010

Stretchability will significantly expand the application scope of electronics, particularly large‐area electronics—displays, sensors, and actuators. If arbitrary surfaces and movable parts could be covered with stretchable electronics, which is impossible with conventional electronics, new classes of applications are expected to emerge. A large hurdle is manufacturing electrical wiring with high conductivity, high stretchability, and large‐area compatibility. This Review describes stretchable, large‐area electronics based on organic field‐effect transistors for applications to sensors and displays. First, novel net‐shaped organic transistors are employed to realize stretchable, large‐area sensor networks that detect distributions of pressure and temperature simultaneously. The whole system is functional even when it is stretched by 25%. In order to further improve stretchability, printable elastic conductors are developed by dispersing single‐walled carbon nanotubes (SWNTs) as dopants uniformly in rubbers. Further, we describe integration of printable elastic conductors with organic transistors to construct a rubber‐like stretchable active matrix for large‐area sensor and display applications. Finally, we will discuss the future prospects of stretchable, large‐area electronics with delineating a picture of the next‐generation human/machine interfaces from the aspect of materials science and electronic engineering.
Chiral Amine Synthesis – Recent Developments and Trends for Enamide Reduction, Reductive Amination, and Imine Reduction
Authors: Nugent Thomas C. , El‐Shazly Mohamed
Published: March 2010

The review examines the chiral amine literature from 2000–2009 (May) concerning enantioselective and diastereoselective methods for N‐acylenamide and enamine reduction, reductive amination, and imine reduction. The reaction steps for each strategy, from ketone to primary chiral amine, are clearly defined, with best methods and yields for starting material preparation and final deprotection noted. Categories of chiral amines have been defined in Section 1 to allow the reader to quickly understand whether their specific target amine falls within a difficult to synthesize, or not, structural class. Amino acids are not considered in this work.
Synthesis and Reactions of Enantiopure Substituted Benzene cis‐Hexahydro‐1,2‐diols
Authors: Boyd D. R. , Sharma N. D. , Berberian M. V. , Dunne K. S. , Hardacre C. , Kaik M. , Kelly B. , Malone J. F. , McGregor S. T. , Stevenson P. J.
Published: March 2010

Enantiopure cis‐dihydro‐1,2‐diol metabolites, obtained from toluene dioxygenase‐catalysed cis‐dihydroxylation of six monosubstituted benzene substrates, have been converted to their corresponding cis‐hexahydro‐1,2‐diol derivatives by catalytic hydrogenation via their cis‐tetrahydro‐1,2‐diol intermediates. Optimal reaction conditions for total catalytic hydrogenation of the cis‐dihydro‐1,2‐diols have been established using six heterogeneous catalysts. The relative and absolute configurations of the resulting benzene cis‐hexahydro‐1,2‐diol products have been unequivocally established by X‐ray crystallography and NMR spectroscopy. Methods have been developed to obtain enantiopure cis‐hexahydro‐1,2‐diol diastereoisomers, to desymmetrise a meso‐cis‐hexahydro‐1,2‐diol and to synthesise 2‐substituted cyclohexanols. The potential of these enantiopure cyclohexanols as chiral reagents was briefly evaluated through their application in the synthesis of two enantiomerically enriched phosphine oxides from the corresponding racemic phosphine precursors.
Selective Hydrogenation of Amides using Ruthenium/ Molybdenum Catalysts
Authors: Beamson Graham , Papworth Adam J , Philipps Charles , Smith Andrew M , Whyman Robin
Published: March 2010

Recyclable, heterogeneous bimetallic ruthenium/molybdenum catalysts, formed in situ from triruthenium dodecacarbonyl [Ru3(CO)12] and molybdenum hexacarbonyl [Mo(CO)6], are effective for the selective liquid phase hydrogenation of cyclohexylcarboxamide (CyCONH2) to cyclohexanemethylamine (CyCH2NH2), with no secondary or tertiary amine by‐product formation. Variation of Mo:Ru composition reveals both synergistic and poisoning effects, with the optimum combination of conversion and selectivity at ca. 0.5, and total inhibition of catalysis evident at ≥1. Good amide conversions are noted within the reaction condition regimes 20–100 bar hydrogen and 145–160 °C. The order of reactivity of these catalysts towards reduction of different amide functional groups is primary>tertiary≫secondary. In situ HP‐FT‐IR spectroscopy confirms that catalyst genesis occurs during an induction period associated with decomposition of the organometallic precursors. Ex situ characterisation, using XRD, XPS and EDX‐STEM, for active Mo:Ru compositions, has provided evidence for intimately mixed ca. 2.5–4 nm particles that contain metallic ruthenium, and molybdenum (in several oxidation states, including zero).
Technical note: PCR analysis of minimum target amount of ancient DNA
Authors: Woide Daniela , Zink Albert , Thalhammer Stefan
Published: March 2010

The study of ancient DNA plays an important role in archaeological and palaeontological research as well as in pathology and forensics. Here, we present a new tool for ancient DNA analysis, which overcomes contamination problems, DNA degradation, and the negative effects of PCR inhibitors while reducing the amount of starting target material in the picogram range. Ancient bone samples from four Egyptian mummies were examined by combining laser microdissection, conventional DNA extraction, and low‐volume PCR. Initially, several bone particles (osteons) in the micrometer range were extracted by laser microdissection. Subsequently, ancient DNA amplification was performed to verify our extraction method. Amelogenin and β‐actin gene specific fragments were amplified via low‐volume PCR in a total reaction volume of 1 μl. Results of microdissected mummy DNA samples were compared to mummy DNA, which was extracted using a standard DNA extraction method based on pulverization of bone material. Our results highlight the combination of laser microdissection and low‐volume PCR as a promising new technique in ancient DNA analysis. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
Interfacial Behavior of Benzoic Acid and Phenylphosphonic Acid on Nanocrystalline TiO2 Surfaces
Authors: Ganbold Erdene‐Ochir , Lee Yunhee , Lee Kangtaek , Kwon Ohyun , Joo Sang‐Woo
Published: March 2010

The interfacial behavior of self‐assembled thin films of benzoic acid (BA) and phenylphosphonic acid (PPOA) anchored on TiO2 surfaces was studied by using temperature‐dependent diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. On the basis of the disappearance of the OH band from the infrared spectra at room temperature, BA and PPOA appear to adsorb onto TiO2 surfaces through carboxylate and phosphonate groups, respectively. Above 420 °C, DRIFT spectra indicated that both BA and PPOA desorb from TiO2 surfaces; however, dissimilar desorption behavior could be inferred for BA and PPOA from their temperature‐dependent spectral changes. The benzene ring modes of PPOA remained above 420 °C, whereas those of BA disappeared. Density functional theory calculations showed that the adsorption of BA and PPOA on TiO2 surfaces corresponded to bidentate bridging geometry on TiO2 surfaces, and the adsorption of PPOA is stronger than that of BA. The monodentate structures with energy differences of 4.9 and 9.1 kcal mol−1 from the most stable bidentate structures of BA and PPOA, respectively, from the DFT calculations appeared to be possible, particularly at the high temperatures above 420 °C, as indicated by the intensified OH bands. The geometry of PPOA was also estimated to be more upright standing than that of BA on TiO2 surfaces, which may lead a rather straight detachment from the TiO2 surfaces based on the presence of in‐plane ring modes in the DRIFT spectra at the higher temperature.
Alkylations of N4‐(4‐Pyridyl)‐3,5‐di(2‐pyridyl)‐1,2,4‐triazole: First Observation of Room‐Temperature Rearrangement of an N4‐Substituted Triazole to the N1 Analogue
Authors: Kitchen Jonathan A. , Larsen David S. , Brooker Sally
Published: March 2010

Attempts to use alkylation to introduce a positive charge at the nitrogen atom of the 4‐pyridyl ring in the bis(bidentate) triazole ligand N4‐(4‐pyridyl)‐3,5‐di(2‐pyridyl)‐1,2,4‐triazole (pydpt) were made to ascertain what effect a strongly electron‐withdrawing group would have on the magnetic properties of any subsequent iron(II) complexes. Alkylation of pydpt under relatively mild conditions led in some cases to unexpected rearrangement products. Specifically, when benzyl bromide is used as the alkylating agent, and the reaction is carried out in refluxing acetonitrile, the N4 substituent moves to the N1 position. However, when the same reaction is performed in dichloromethane at room temperature, the rearrangement does not occur and the desired product containing an alkylated N4 substituent is obtained. Heating a pure sample of N4‐Bzpydpt⋅Br to reflux in MeCN resulted in clean conversion to N1Bzpydpt.Br. This is consistent with N4‐Bzpydpt.Br being the kinetic product whereas N1Bzpydpt.Br is the thermodynamic product. When methyl iodide is used as the alkylating agent, the N4 to N1 rearrangement occurs even at room temperature, and at reflux pydpt is doubly alkylated. The observation of the lowest reported temperatures for an N4 to N1 rearrangement is due to this particular rearrangement involving nucleophilic aromatic substitution: a possible mechanism for this transformation is suggested.
The evolution of chaos in active galaxy models with an oblate or a prolate dark halo component
Authors: Caranicolas N.D. , Zotos E.E.
Published: March 2010

The evolution of chaotic motion in a galactic dynamical model with a disk, a dense nucleus and a flat biaxial dark halo component is investigated. Two cases are studied: (i) the case where the halo component is oblate and (ii) the case where a prolate halo is present. In both cases, numerical calculations show that the extent of the chaotic regions decreases exponentially as the scale‐length of the dark halo increases. On the other hand, a linear relationship exists between the extent of the chaotic regions and the flatness parameter of the halo component. A linear relationship between the critical value of the angular momentum and the flatness parameter is also found. Some theoretical arguments to support the numerical outcomes are presented. An estimation of the degree of chaos is made by computing the Lyapunov Characteristic Exponents. Comparison with earlier work is also made (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sixty four nights of UBV photometry of early‐type stars at La Sila
Authors: Mayer P. , Božić H. , Lorenz R. , Drechsel H.
Published: March 2010

UBV measurements of early‐type stars, mostly eclipsing binaries, obtained at La Silla in the years 1990 to 1994 with the ESO 50 cm telescope are presented. Most of these data were already used in our individual studies of several binaries. Now all photometric measurements were reduced again with an advanced technique and are made available electronically. Our data for MY Ser have not yet been published; new light curve is given and solved. The result is that MY Ser is a contact binary, with very large fill‐out parameter. Also a light curve and its solution for V1051 Cen are provided, and the problem of the period of V871 Cen is pointed out. Besides binaries (and the comparison and check stars) data for several stars in southern H II regions are included. Extinction and transformation coefficients are given (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Four‐colour photometry of EY Dra: A study of an ultra‐fast rotating active dM1‐2e star
Authors: Vida K. , Oláh K. , Kőväri Zs. , Jurcsik J. , Sódor Á. , Váradi M. , Belucz B. , Dékány I. , Hurta Zs. , Nagy I. , Posztobányi K.
Published: March 2010

We present more than 1000‐day long photometry of EY Draconis in BV (RI)C passbands. The changes in the light curve are caused by the spottedness of the rotating surface. Modelling of the spotted surface shows that there are two large active regions present on the star on the opposite hemispheres. The evolution of the surface patterns suggests a flip‐flop phenomenon. Using Fourier analysis, we detect a rotation period of Prot = 0.45875 d, and an activity cycle with P ≈ 350 d, similar to the 11‐year long cycle of the Sun. This cycle with its year‐long period is the shortest one ever detected on active stars. Two bright flares are also detected and analysed (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carotenoid and fatty acid metabolism in light‐stressed Dunaliella salina
Authors: Lamers Packo P. , van de Laak Carlien C.W. , Kaasenbrood Petrouchka S. , Lorier Jeroen , Janssen Marcel , De Vos Ric C.H. , Bino Raoul J. , Wijffels René H.
Published: March 2010

β‐Carotene is overproduced in the alga Dunaliella salina in response to high light intensities. We have studied the effects of a sudden light increase on carotenoid and fatty acid metabolism using a flat panel photobioreactor that was run in turbidostat mode to ensure a constant light regime throughout the experiments. Upon the shift to an increased light intensity, β‐carotene production commenced immediately. The first 4 h after induction were marked by constant intracellular levels of β‐carotene (2.2 g LCV−1), which resulted from identical increases in the production rates of cell volume and β‐carotene. Following this initial phase, β‐carotene productivity continued to increase while the cell volume productivity dropped. As a result, the intracellular β‐carotene concentration increased reaching a maximum of 17 g LCV−1 after 2 days of light stress. Approximately 1 day before that, the maximum β‐carotene productivity of 30 pg cell−1 day−1 (equivalent to 37 mg LRV−1 day−1) was obtained, which was about one order of magnitude larger than the average productivity reported for a commercial β‐carotene production facility, indicating a vast potential for improvement. Furthermore, by studying the light‐induced changes in both β‐carotene and fatty acid metabolism, it appeared that carotenoid overproduction was associated with oil globule formation and a decrease in the degree of fatty acid unsaturation. Our results indicate that cellular β‐carotene accumulation in D. salina correlates with accumulation of specific fatty acid species (C16:0 and C18:1) rather than with total fatty acid content. Biotechnol. Bioeng. 2010;106: 638–648. © 2010 Wiley Periodicals, Inc.
Characterization and applications of serum‐free induced adhesion in jurkat suspension cells
Authors: Audiffred Julianne F. , De Leo Sarah E. , Brown Paige K. , Hale‐Donze Hollie , Monroe W. Todd
Published: March 2010

In this study, we demonstrate that the presence of serum in different media plays an important role in inducing transient and reversible adhesion in Jurkat suspension cells. Attachment of Jurkat cells in two distinct media formulations (serum‐fortified and serum‐free) to untreated polystyrene (PS), plasma‐treated PS, and fibronectin‐coated PS was compared. Additional analysis characterized the occurrence of this transient cell adhesion, including attachment rate, reversibility of attachment, and viability and preservation of phenotype in cells during and after attachment. As a demonstration of the utility of this technique, a few applications of transiently adhering Jurkat cells are shown which would be otherwise difficult with freely suspended cells, such as increased gene delivery, confocal‐based apoptosis detection, and real‐time electric‐field effect monitoring in Jurkat cells. Biotechnol. Bioeng. 2010;106: 784–793. © 2010 Wiley Periodicals, Inc.
Ring‐Opening Metathesis Polymerization Based Pore‐Size‐Selective Functionalization of Glycidyl Methacrylate Based Monolithic Media: Access to Size‐Stable Nanoparticles for Ligand‐Free Metal Catalysis
Authors: Bandari Rajendar , Höche Thomas , Prager Andrea , Dirnberger Klaus , Buchmeiser Michael R.
Published: March 2010

Monolithic polymeric supports have been prepared by electron‐beam‐triggered free‐radical polymerization using a mixture of glycidyl methacrylate and trimethylolpropane triacrylate in 2‐propanol, 1‐dodecanol, and toluene. Under appropriate conditions, phase separation occurred, which resulted in the formation of a porous monolithic matrix that was characterized by large (convective) pores in the 30 μm range as well as pores of <600 nm. The epoxy groups in pores of >7 nm were hydrolyzed by using poly(styrenesulfonic acid) (Mw=69 400 g mol−1, PDI=2.4). The remaining epoxy groups inside pores of <7 nm were subjected to aminolysis with norborn‐5‐en‐2‐ylmethylamine (2) and provided covalently bound norborn‐2‐ene (NBE) groups inside these pores. These NBE groups were then treated with the first‐generation Grubbs initiator [RuCl2(PCy3)2(CHPh)]. These immobilized Ru–alkylidenes were further used for the surface modification of the small pores by a grafting approach. A series of monomers, that is, 7‐oxanorborn‐5‐ene‐2,3‐dicarboxylic anhydride (3), norborn‐5‐ene‐2,3‐dicarboxylic anhydride (4), N,N‐di‐2‐pyridyl‐7‐oxanorborn‐5‐ene‐2‐carboxylic amide (5), N,N‐di‐2‐pyridylnorborn‐5‐ene‐2‐carboxamide (6), N‐[2‐(dimethylamino)ethyl]bicyclo[2.2.1]hept‐5‐ene‐2‐carboxamide (7), and dimethyl bicyclo[2.2.1]hept‐5‐en‐2‐ylphosphonate (8), were used for this purpose. Finally, monoliths functionalized with poly‐5 graft polymers were used to permanently immobilize Pd2+ and Pt4+, respectively, inside the pores. After reduction, metal nanoparticles 2 nm in diameter were formed. The palladium‐nanoparticle‐loaded monoliths were used in both Heck‐ and Suzuki‐type coupling reactions achieving turnover numbers of up to 167 000 and 63 000, respectively.
N,N′‐Methylenediimidazolium Salts: From Self‐Assembly to an Efficient DNAse Protection System
Authors: Pardin Christophe , Leclercq Loïc , Schmitzer Andreea R.
Published: March 2010

We have developed N,N′‐dialkylmethylenediimidazolium salts ([CnCnDIM][X]2) that self‐organize into multilayered cationic vesicles and can interact with DNA. These preorganized systems form complexes with linear DNA and protect it from DNase I cleavage.
Homoleptic Tris(Pyridyl Pyrazolate) IrIII Complexes: En Route to Highly Efficient Phosphorescent OLEDs
Authors: Chen Kellen , Yang Cheng‐Han , Chi Yun , Liu Chao‐Shiuan , Chang Chih‐Hao , Chen Chung‐Chia , Wu Chung‐Chih , Chung Min‐Wen , Cheng Yi‐Ming , Lee Gene‐Hsiang , Chou Pi‐Tai
Published: March 2010

Treatment of the metal reagent IrCl3⋅nH2O with two equivalents of 2‐pyridyl pyrazole (N^N)H (3‐tert‐butyl‐5‐(2‐pyridyl) pyrazole, (bppz)H and 3‐trifluoromethyl‐5‐(2‐pyridyl) pyrazole, (fppz)H), afforded the isomeric IrIII metal complexes with a general formula cis‐[Ir(bppz)2Cl2]H (2 a), trans‐[Ir(bppz)2Cl2]H (3 a), cis‐[Ir(fppz)2Cl2]H (2 b), and trans‐[Ir(fppz)2Cl2]H (3 b). Single‐crystal X‐ray diffraction studies on 2 b and 3 a revealed the coexistence of two pyrazolate chelates and two terminal chloride ligands on the coordination sphere. Subsequent reactivity studies confirmed their intermediacy to the preparation of homoleptic mer‐[Ir(bppz)3] (1 a) and mer‐[Ir(fppz)3] (1 b) that showed dual intraligand and ligand‐to‐ligand charge‐transfer phosphorescence at room temperature. To attain bright, room‐temperature phosphorescence further, we then synthesized two isoquinolinyl pyrazolate complexes, mer‐[Ir(bipz)3] (4 a) and mer‐[Ir(fipz)3] (4 b) ((bipz)H=3‐tert‐butyl‐5‐(1‐isoquinolyl) pyrazole and (fipz)H=3‐trifluoromethyl‐5‐(1‐isoquinolyl) pyrazole). Their orange luminescence is mainly attributed to the mixed MLCT/ππ* transition, and the quantum yields were as high as 86 (4 a) and 50 % (4 b) in degassed CH2Cl2 solution at RT. The organic light‐emitting diodes (OLEDs) were then fabricated by using 4 a as a dopant, giving orange luminescence with CIEx,y=0.55, 0.45 (CIEx,y=the 1931 Commission Internationale de L’Eclairage (x,y) coordinates) and peak efficiencies of 14.6 % photon/electron, 34.8 cd A−1, 26.1 lm W−1. The device data were then compared with the previously reported heteroleptic complex [Ir(dfpz)2(bipz)] (5) ((dfpz)H=1‐(2,4‐difluorophenyl) pyrazole), revealing the possible effect of the bipz chelate and phosphor design on the overall electrophosphorescent performance, which can be understood by the differences in the carrier‐transport properties.
A Conjugated Thiophene‐Based Rotaxane: Synthesis, Spectroscopy, and Modeling
Authors: Zalewski Leszek , Wykes Michael , Brovelli Sergio , Bonini Massimo , Breiner Thomas , Kastler Marcel , Dötz Florian , Beljonne David , Anderson Harry L. , Cacialli Franco , Samorì Paolo
Published: March 2010

A dithiophene rotaxane 1⊂β‐CD and its shape‐persistent corresponding dumbbell 1 were synthesized and fully characterized. 2D NOESY experiments, supported by molecular dynamics calculations, revealed a very mobile macrocycle (β‐CD). Steady‐state and time‐resolved photoluminescence experiments in solution were employed to elucidate the excited‐state dynamics for both systems and to explore the effect of cyclodextrin encapsulation. The photoluminescence (PL) spectrum of 1⊂β‐CD was found to be blueshifted with respect to the dumbbell 1 (2.81 and 2.78 eV, respectively). Additionally, in contrast to previous observations, neither PL spectra nor the decay kinetics of both threaded and unthreaded systems showed changes upon increasing the concentration or changing the polarity of the solutions, thereby providing evidence for a lack of tendency toward aggregation of the unthreaded backbone.
Study of the Light‐Induced Spin Crossover Process of the [FeII(bpy)3]2+ Complex
Authors: de Graaf Coen , Sousa Carmen
Published: March 2010

Ab initio calculations have been performed on [FeII(bpy)3]2+ (bpy=bipyridine) to establish the variation of the energy of the electronic states relevant to light‐induced excited‐state spin trapping as a function of the Feligand distance. Light‐induced spin crossover takes place after excitation into the singlet metal‐to‐ligand charge‐transfer (MLCT) band. We found that the corresponding electronic states have their energy minimum in the same region as the low‐spin (LS) state and that the energy dependence of the triplet MLCT states are nearly identical to the 1MLCT states. The high‐spin (HS) state is found to cross the MLCT band near the equilibrium geometry of the MLCT states. These findings give additional support to the hypothesis of a fast singlet–triplet interconversion in the MLCT manifold, followed by a 3MLCT–HS (5T2) conversion accompanied by an elongation of the FeN distance.
A Highly Potent and Selective Caspase 1 Inhibitor that Utilizes a Key 3‐Cyanopropanoic Acid Moiety
Authors: Boxer Matthew B. , Quinn Amy M. , Shen Min , Jadhav Ajit , Leister William , Simeonov Anton , Auld Douglas S. , Thomas Craig J.
Published: March 2010

Herein, we examine the potential of a nitrile‐containing propionic acid moiety as an electrophile for covalent attack by the active‐site cysteine residue of caspase 1. The syntheses of several cyanopropanate‐containing small molecules based on the optimized peptidic scaffold of prodrug VX‐765 were accomplished. These compounds were found to be potent inhibitors of caspase 1 (IC50 values ≤1 nM). Examination of these novel small molecules against a caspase panel demonstrated an impressive degree of selectivity for caspase 1 inhibition over other caspase isozymes. Assessment of hydrolytic stability and selected ADME properties highlighted these agents as potentially useful tools for studying caspase 1 down‐regulation in various settings, including in vivo analyses.
An efficient curvilinear non‐hydrostatic model for simulating surface water waves
Authors: Choi Doo Yong , Wu Chin H. , Young Chih‐Chieh
Published: March 2010

An efficient curvilinear non‐hydrostatic free surface model is developed to simulate surface water waves in horizontally curved boundaries. The generalized curvilinear governing equations are solved by a fractional step method on a rectangular transformed domain. Of importance is to employ a higher order (either quadratic or cubic spline function) integral method for the top‐layer non‐hydrostatic pressure under a staggered grid framework. Model accuracy and efficiency, in terms of required vertical layers, are critically examined on a linear progressive wave case. The model is then applied to simulate waves propagating in a canal with variable widths, cnoidal wave runup around a circular cylinder, and three‐dimensional wave transformation in a circular channel. Overall the results show that the curvilinear non‐hydrostatic model using a few, e.g. 2–4, vertical layers is capable of simulating wave dispersion, diffraction, and reflection due to curved sidewalls. Copyright © 2010 John Wiley & Sons, Ltd.
The foundation‐institution partnership: The role of institutionally related foundations in public higher education
Authors: Bass David
Published: March 2010

Institutionally related foundations play an important role in helping public colleges and universities realize their aspirations to receive private philanthropic dollars. This chapter contains practical advice for maintaining a successful foundation and fostering a positive relationship between that organization and its host institution.
Characterization of poly(ethylene glycol) gels with added collagen for neural tissue engineering
Authors: Scott Rebecca , Marquardt Laura , Willits Rebecca Kuntz
Published: March 2010

Over the past decade, it has been increasingly recognized that both chemical and mechanical properties of scaffolds influence neural cell behavior, ranging from growth to differentiation to migration. However, mechanical properties are difficult to control for in the design of scaffolds for nerve regeneration, as properties change over time for most biologically derived scaffolds. The focus of this project was to examine how the mechanical properties of a nondegradable scaffold, poly(ethylene glycol) (PEG) gels, influenced nerve cell behavior. Low concentration PEG gels, of 3, 4, or 5% PEG, with added collagen to alter chemical properties were examined for both their mechanical properties and their ability to support nerve expression and extension. Stiffness (G*) significantly increased with increased PEG concentration. The addition of chemically conjugated collagen significantly decreased the stiffness compared to plain gels. This phenomenon was confirmed to be an effect of the conjugate, and not the protein itself, as G* of gels containing conjugate, but no protein, was not significantly different than G* of gels with conjugated protein. PC12 cell neurite expression increased with decreasing PEG and increasing collagen concentration. At its best, the expression approached the value on collagen‐coated tissue culture plastic, which is a substantial improvement over previous studies on PEG. Neurite extension of dorsal root ganglia was also improved on these same gels over gels with either higher PEG concentration or lower collagen amount. Overall, these results suggest that exploration of lower stiffness materials is necessary to improve neurite growth and extension in three‐dimensional synthetic scaffolds. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Mechanism and Modeling of Emulsion Polymerization: New Ideas and Concepts – 1. Particle Nucleation
Authors: Tauer Klaus , Nazaran Pantea
Published: March 2010

Summary: New experimental data for nucleation in emulsion polymerization prove that the process is heterogeneous in nature so that water‐borne oligomers precipitate at the surface of monomer drops. The particle morphology at the early stage of the process is strongly influenced by the initiator concentration. The hydrophilicity of the monomer is less important as methyl methacrylate, styrene, and 4‐tert‐butyl styrene show similar behaviour.
Dissipative Structure in the Course of Drying Suspensions and Solutions
Authors: Okubo Tsuneo
Published: March 2010

Summary: Convectional, sedimentation and drying dissipative patterns during the course of dryness of suspensions and solutions are reviewed. The whole processes of convection were analyzed in the seven steps: irregular circulation accompanied with the upward heat transportation, global convectional flow from the central area toward outside edge at the surface layers of liquid, cooperative formation of distorted Benard cells, reversal of global flow of convection, growing of the spoke lines from the outside edge toward central area at the liquid surface layers, cluster and further bundle formation of the spoke lines, and the convectional flow by the pinning effect. The sedimentary colloidal particles were suspended above the substrate by the electric double layers and moved by the balancing of the external force fields including convectional flow and sedimentation. Principal macroscopic drying patterns are broad rings and spoke lines. Microscopic patterns such as star, needle, street road, string and cross‐like are formed. The stratified structures form from micro to macro scales. Information on the size, shape, conformation and/or flexibility of particles or polymers is transferred cooperatively, and further accompanied with the amplification and selection processes during the course of dryness.
Photon Trapping and the Enhancement of Electronic Excitation Energy Transfer Efficiency Caused by Colloidal Crystals
Authors: Tsuchida Akira , Ohi Yuji , Takahashi Shinya , Kimura Hiroshi , Okubo Tsuneo
Published: March 2010

Summary: The efficiency of electronic excitation energy transfer from photoexcited fluorescein to rhodamine 6G is enhanced by 2.26 times in an exhaustively deionized colloidal silica suspension. This enhancement is caused by the photon trapping effects due to the Bragg reflection of colloidal crystals formed in the suspension. The lower enhancement efficiency of 1.41 times observed for rhodamine B as an acceptor is attributed to the inefficient spectral overlap between donor fluorescence and acceptor absorption bands.
Quantification method affects estimates of voluntary quadriceps activation
Authors: Krishnan Chandramouli , Williams Glenn N.
Published: March 2010

The aim of this study was to investigate the effect of quantification method on estimates of voluntary quadriceps muscle activation. Twenty‐two people with no history of serious lower extremity injuries underwent voluntary quadriceps activation testing at 60° of knee flexion. Estimates of quadriceps activation were derived with: (1) a formula based on the interpolated twitch technique (ITT); (2) the central activation ratio (CAR); and (3) a modified central activation ratio. Predictive equations were developed that describe the relationships between the three methods. Significant differences (P < 0.001) were observed between the estimates of voluntary quadriceps muscle activation obtained using the three methods (ITT percent activation = 93.0 ± 6.4%, CAR = 95.9 ± 3.8%, modified CAR = 98.5 ± 4.1%). Excellent correlation (r = 0.995) was observed between ITT‐based percent activation and the CAR method. The associations between these methods and the modified CAR approach were weaker. Quantification method affects activation estimates. The equations developed will assist scientists in accurately comparing the results of studies that use different methods of quantifying activation. Muscle Nerve, 2010
SERPINB3 induces epithelial–mesenchymal transition
Authors: Quarta Santina , Vidalino Laura , Turato Cristian , Ruvoletto Mariagrazia , Calabrese Fiorella , Valente Marialuisa , Cannito, Stefania , Fassina Giorgio , Parola Maurizio , Gatta Angelo , Pontisso Patrizia
Published: March 2010

Epithelial–mesenchymal transition is believed to facilitate invasion and metastasis formation of epithelial tumour cells. SERPINB3 is a serine protease inhibitor, physiologically found in normal squamous epithelium but over‐expressed in epithelial tumours and known to inhibit apoptosis. We tested the hypothesis that SERPINB3 has a role in invasion by modulating the epithelial–mesenchymal transition programme, using morphological, molecular and cell biology techniques on HepG2 cell clones transfected with the human SERPINB3 gene. The paracrine effect of this serpin was determined by the addition of exogenous recombinant SERPINB3 protein to HepG2 and MDCK cell line. SERPINB3 expression leads to changes in transfected cells morphology, characterized by clusters of loosely connected cells with elongated shape. Ultrastructural analysis confirmed the decrease of desmosomal junctions and widening of intercellular spaces. These alterations were associated with a reduction of E‐cadherin and an increase of β‐catenin, with a parallel increase of cell proliferation. SERPINB3 clones, untransfected HepG2 and MDCK cells treated with exogenous SERPINB3 expressed vimentin, undetectable in controls. SERPINB3 induced significant cell scattering, migration and invasiveness in untransfected cells. These effects were not dependent on the anti‐protease activity of the protein, as documented by the results obtained with an active loop‐deleted recombinant SERPINB3 protein. Scatter activity was inhibited by an anti‐SERPINB3 antibody in a dose‐dependent manner and SERPINB3‐transfected cells formed a significantly higher number of colonies on soft agar than controls. In conclusion, the observed results indicate that SERPINB3 induces deregulation of adhesion processes and increases the invasiveness potential supported by features of epithelial–mesenchymal transition, acting at both the autocrine and the paracrine level. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The mechanisms underlying fibroblast apoptosis regulated by growth factors during wound healing
Authors: Akasaka Yoshikiyo , Ono Ichiro , Kamiya Takafumi , Ishikawa Yukio , Kinoshita Toshio , Ishiguro Shigeki , Yokoo Tomoko , Imaizumi Risa , Inomata Naomi , Fujita Kazuko , Akishima‐Fukasawa Yuri , Uzuki Miwa , Ito Kinji , Ishii Toshiharu
Published: March 2010

While investigating the mechanisms underlying cell death during wound healing processes, we uncovered the pro‐apoptotic effects of basic fibroblast growth factor (bFGF) on granulation tissue fibroblasts following pretreatment with transforming growth factor (TGF)‐β1 in vitro. bFGF induced caspse‐3 activation and apoptosis in TGF‐β1‐pretreated granulation tissue‐derived fibroblasts (GF‐1) following bFGF treatment for 48 and 96 h. In contrast, fibroblasts that had been treated in the same manner and that originated from the uninjured dermis did not display apoptosis, indicating that the mechanisms underlying apoptosis events in fibroblasts that originate from normal dermal and wound tissues differ. In this process, we also found that bFGF inhibited Akt phosphorylation at serine 473 and induced a rapid loss of phosphorylation of focal adhesion kinase (FAK) at tyrosine 397 in pretreated GF‐1 cells, an event that coincided with the dissociation of phosphorylated FAK from the focal adhesions. Therefore, inhibition of survival signals relayed via the disrupted focal adhesion structures and inactivated Akt following bFGF treatment may lead to apoptosis in GF‐1 cells pretreated with TGF‐β1. Pretreatment of GF‐1 with TGF‐β1 followed by the addition of bFGF resulted in significantly greater inhibition of phosphorylation of Akt and FAK compared to treatment with TGF‐β1 or bFGF alone. The combinatorial treatment also led to proteolysis of FAK and inhibition of FAK and Akt protein expression in GF‐1 cells. These findings demonstrated a significant role for the two cytokines in apoptosis of granulation tissue fibroblasts during wound healing. In vivo studies also confirmed a marked decline in phosphorylation and protein expression of Akt and FAK in bFGF‐injected skin wounds. These results led to the hypothesis that temporal activation of TGF‐β1 and bFGF at the injury site promotes apoptosis in granulation tissue fibroblasts, an event that is critical for the termination of proliferative granulation tissue formation. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Phase I study of valspodar (PSC‐833) with mitoxantrone and etoposide in refractory and relapsed pediatric acute leukemia: A report from the Children's Oncology Group
Authors: O'Brien Maureen M. , Lacayo Norman J. , Lum Bert L. , Kshirsagar Smita , Buck Steven , Ravindranath Yaddanapudi , Bernstein Mark , Weinstein Howard , Chang Myron N. , Arceci Robert J. , Sikic Branimir I. , Dahl Gary V.
Published: March 2010

Background

Valspodar, a non‐immunosuppressive analog of cylosporine, is a potent P‐glycoprotein (MDR1) inhibitor. As MDR1‐mediated efflux of chemotherapeutic agents from leukemic blasts may contribute to drug resistance, a phase 1 study of valspodar combined with mitoxantrone and etoposide in pediatric patients with relapsed or refractory leukemias was performed.

Procedure

Patients received a valspodar‐loading dose (2 mg/kg) followed by a 5‐day continuous valspodar infusion (8, 10, 12.5, or 15 mg/kg/day) combined with lower than standard doses of mitoxantrone and etoposide. The valspodar dose was escalated using a standard 3 + 3 phase I design.

Results

Twenty‐one patients were evaluable for toxicity and 20 for response. The maximum tolerated dose (MTD) of valspodar was 12.5 mg/kg/day, combined with 50% dose‐reduced mitoxantrone and etoposide. The clearance of mitoxantrone and etoposide was decreased by 64% and 60%, respectively, when combined with valspodar. Dose‐limiting toxicities included stomatitis, ataxia, and bone marrow aplasia. Three of 11 patients with acute lymphoblastic leukemia (ALL) had complete responses while no patient with acute myeloid leukemia (AML) had an objective response. In vitro studies demonstrated P‐glycoprotein expression on the blasts of 5 of 14 patients, although only 1 had inhibition of rhodamine efflux by valspodar.

Conclusions

While this regimen was tolerable, responses in this heavily pretreated population were limited to a subset of patients with ALL. Pediatr Blood Cancer 2010;54:694–702. © 2010 Wiley‐Liss, Inc.
Stanozolol treatment for successful prevention of attacks of severe primary cryofibrinogenemia
Authors: Unal Sule , Kara Fehime , Ozen Seza , Orhan Diclehan , Tuncer Murat , Gumruk Fatma
Published: March 2010

Severe essential cryofibrinogenemia is rare in childhood, and both the diagnosis and the management are challenging for pediatricians. An 11‐year‐old male, who had already lost two digits following cold exposure, was referred after multiple visits to various hospitals and subsequently diagnosed as primary cryofibrinogenemia. His history revealed unresponsiveness to calcium channel blockers, acetyl salicylic acid, pentoxifylline, dextran, and steroids. Stanozolol (2 mg/day, orally) prophylaxis was initiated and no new skin lesions developed following starting this treatment. Some of the newly formed lesions at the onset of stanozolol healed. Pediatr Blood Cancer 2010;55:174–176. © 2010 Wiley‐Liss, Inc.
Modelling c‐Si/SiNx interface recombination by surface damage
Authors: Steingrube Silke , Altermatt Pietro P. , Schmidt Jan , Brendel Rolf
Published: March 2010

Amorphous silicon nitride (SiNx) layers are widely used for the electronic passivation of surfaces in Si solar cells. However, measurements have consistently shown that the effective recombination velocity Seff increases with decreasing excess carrier density Δn < 1015 cm–3 at acceptor densities below 1017 cm–3. This poor performance is not observed at surfaces diffused with dopants, which requires an additional high temperature process during cell fabrication. Understanding the poor performance at low Δn may therefore provide strate gies for cost reduction in solar cell processing. This paper presents a detailed quantitative analysis of this effect. It is concluded that the lifetime is reduced to a value near 1 μs in a 100–500 nm thin region underneath the SiNx layer. We predict, that to avoid this effect, a mere tenfold reduction of the density of defect states in this region is sufficient. A possible explanation of this effect are defects caused by H‐termination during wafer pretreatment. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Representing and using scenarios for responding to climate change
Authors: Rosentrater Lynn D.
Published: March 2010

Scenarios have become a standard tool in climate studies and provide the basis for our understanding of climate‐related challenges, the mechanisms for adaptation, and options for mitigation. They can be thought of in two ways: either as products that describe outcomes resulting from specific driving forces, or as processes for establishing long‐term planning targets. Common scenario types include emissions scenarios, climate change scenarios, and socioeconomic scenarios, all of which are used in strategic planning to compare the potential consequences of different future contexts. Scenario‐based studies also shape the information that is used to motivate the changes in behavior that are needed to achieve mitigation goals. This review presents some of the issues that arise when using scenarios for responding to climate change. Uncertainties associated with scenario approaches are an apparent barrier to the development of policies regarding climate change, especially at local and national scales. Scenarios are also ineffective at addressing noncognitive influences on climate change perception and therefore do not stimulate behavioral change. Copyright © 2010 John Wiley & Sons, Inc.

This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Behavior Change and Responses
Network reliability evaluation
Authors: Sahinoglu Mehmet , Rice Benjamin
Published: March 2010

This article, beyond presenting a spectrum of network reliability methods studied in the past decades, describes a scalable innovative ‘overlap technique’ to tackle large complex networks' reliability evaluation difficulties, which cannot be handled by straightforward reliability block diagramming (RBD) techniques used for the simple parallel‐series topologies. Examples are shown on how to apply the overlap algorithm to compute the ingress‐egress reliability. Monte Carlo simulations demonstrate the methods discussed. (1) Static (time independent), (2) dynamic (time dependent) using a versatile Weibull distribution to represent the multiple stages of network components from infancy to useful life period and to wear‐out, and (3) multistate versions to include derated behavior beyond conventional working and nonworking states, are illustrated for calculating the directional source‐target (s‐t) reliability of complex networks by using the Java software ERBDC:Exact Reliability Block Diagramming Calculator. Copyright © 2010 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Reliability, Survivability, and Quality Control
Three New Iron(II) Thiocyanato Coordination Polymers Based on 4,4′‐Bipyridine as Ligand and the Influence of Methanol on Their Structures
Authors: Wriedt Mario , Näther Christian
Published: March 2010

Reaction of iron(II) thiocyanate with 4,4‐bipyridine (bipy) in methanol leads to the formation of three new solvates of different composition depending on the reaction conditions: At room temperature two new ligand‐rich 1:2 (1:2 = ratio between metal and N‐donor ligand) polymorphic forms [Fe(NCS)2(bipy)2·2MeOH]n (1I) and [Fe(NCS)2(bipy)(MeOH)2·(bipy)]n (1II) are obtained, whereas solvothermal conditions leads to the formation of the new ligand‐deficient 1:1 compound [{Fe(NCS)2(bipy)(MeOH)}2]n (2). All crystal structures were determined by X‐ray single crystal structure analysis. In the crystal structure of modification 1I the metal atoms are coordinated by four bridging bipy ligands, which connect them into layers. The methanol molecules occupy voids in the structure. Compared to 1I in modification 1II the crystal structure contains of linear Fe–bipy–Fe chains, which are further connected by hydrogen bonds between coordinating MeOH and noncoordinated bipy ligands into layers. The ligand‐deficient 1:1 compound 2 shows a completely different coordination topology with linear Fe–bipy–Fe chains, which are connected by coordinating methanol molecules into double‐chains. In all compounds the thiocyanato anions are terminal N‐bonded to the metal atoms. Investigation of the thermal behavior of compound 1I shows a two‐step decomposition, in which ligand‐deficient intermediates are formed. Magnetic measurements on 1I reveal Curie–Weiss paramagnetism with increasing antiferromagnetic interactions on cooling.
Tendenzen in der raumbezogenen Forschung
Authors: Gnest Holger , Roggendorf Wolfgang , Fürst Dietrich
Published: March 2010

To prepare the research framework 2000–2005 of the Academy for Regional Research and Regional Planning, a search in relevant internet sources from the fields of research, consultancy and administration was carried out. The interpretation could not be absolutely representative since the information supply was very different. Nevertheless, some topics can be regarded as “big issues”: Implementation and design of sustainability, spatial development in the context of globalization of economy, politics and society, world wide connected cities and agglomerations, the effect of scientific progress, especially in information technology, transport and the changing role of the state and its institutions. Finally some conclusions are drawn concerning the investigation methods and how to deal with these big issues.
Westdeutsche Kommunen und der demographische Wandel
Authors: Langhagen-Rohrbach Christian , Gretschel Sandra
Published: March 2010

Policy and practice perspective
Zur Ermittlung des Gewerbeflächenbedarfs
Authors: Bonny Hanns Werner
Published: March 2010

Policy and practice perspective
Neue Wege der Verkehrswegefinanzierung im Spiegel raumordnerischer Ziele und Grundsätze
Authors: Laaser Claus -Friedrich , Jakubowski Peter
Published: March 2010

The first privately operated motorway projects and heavy truck toll collection schemes on German motorways are components of an intensified integration of road usage and financing. Distance-related user charges could entail higher transport costs for peripheral regions. An empirical analysis for Germany reveals that concerning freight transport peripheral regions might be charged twice compared to more central regions, albeit at rather low shares of transport costs in revenues. Concerning car traffic, the urban fringe of agglomerations would bear the highest transport cost increments. Higher transport costs for peripheral regions and, as a consequence, a more compact spatial division of labour might be at odds with the regional equity objective, but would match other objectives of regional planning.
Rückläufige Verkehrsmengen?!
Authors: Liebe Lars , Weiß Ute
Published: March 2010

This article considers the extent to which it is now necessary to make adjustments to socalled “functional road networks”, an instrument of comprehensive spatial planning, in response to changes in demographics. Drawing on a case-study of the Central Thuringia planning region, the analysis focuses initially on the question of whether population shrinkage and ageing actually impact on levels of road traffic, or whether their effects are offset by other factors. As the authors report, road-traffic volumes are no longer growing relentlessly; in the period between 1995 and 2000, they were, in some areas, already in decline. Additional growth in the future is likely, however, essentially on those routes which are of European significance, whilst the more sparsely populated rural regions are expected to see a continuing decline in traffic levels. The conclusion drawn by the authors in the light of prevailing demographic and financial circumstances is that regional planning can — and should — no longer go on calling for the expansion of all categories of the functional road network on a large scale (as has previously happened in Central Thuringia); it should rather address the issues thrown up by the actual development of traffic volumes.